Annotation of /trunk/kernel26-magellan/patches-2.6.21-r4/0153-2.6.21-unionfs-2.0-u2.patch
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Tue Jun 12 08:03:28 2007 UTC (16 years, 11 months ago) by niro
File size: 247073 byte(s)
Tue Jun 12 08:03:28 2007 UTC (16 years, 11 months ago) by niro
File size: 247073 byte(s)
files for 2.6.21-magellan-r4
1 | niro | 222 | diff --git a/Documentation/filesystems/00-INDEX b/Documentation/filesystems/00-INDEX |
2 | index 5717858..2ef035e 100644 | ||
3 | --- a/Documentation/filesystems/00-INDEX | ||
4 | +++ b/Documentation/filesystems/00-INDEX | ||
5 | @@ -84,6 +84,8 @@ udf.txt | ||
6 | - info and mount options for the UDF filesystem. | ||
7 | ufs.txt | ||
8 | - info on the ufs filesystem. | ||
9 | +unionfs/ | ||
10 | + - info on the unionfs filesystem | ||
11 | vfat.txt | ||
12 | - info on using the VFAT filesystem used in Windows NT and Windows 95 | ||
13 | vfs.txt | ||
14 | diff --git a/Documentation/filesystems/unionfs/00-INDEX b/Documentation/filesystems/unionfs/00-INDEX | ||
15 | new file mode 100644 | ||
16 | index 0000000..96fdf67 | ||
17 | --- /dev/null | ||
18 | +++ b/Documentation/filesystems/unionfs/00-INDEX | ||
19 | @@ -0,0 +1,10 @@ | ||
20 | +00-INDEX | ||
21 | + - this file. | ||
22 | +concepts.txt | ||
23 | + - A brief introduction of concepts. | ||
24 | +issues.txt | ||
25 | + - A summary of known issues with unionfs. | ||
26 | +rename.txt | ||
27 | + - Information regarding rename operations. | ||
28 | +usage.txt | ||
29 | + - Usage information and examples. | ||
30 | diff --git a/Documentation/filesystems/unionfs/concepts.txt b/Documentation/filesystems/unionfs/concepts.txt | ||
31 | new file mode 100644 | ||
32 | index 0000000..83d45b9 | ||
33 | --- /dev/null | ||
34 | +++ b/Documentation/filesystems/unionfs/concepts.txt | ||
35 | @@ -0,0 +1,75 @@ | ||
36 | +Unionfs 2.0 CONCEPTS: | ||
37 | +===================== | ||
38 | + | ||
39 | +This file describes the concepts needed by a namespace unification file | ||
40 | +system. | ||
41 | + | ||
42 | +Branch Priority: | ||
43 | +================ | ||
44 | + | ||
45 | +Each branch is assigned a unique priority - starting from 0 (highest | ||
46 | +priority). No two branches can have the same priority. | ||
47 | + | ||
48 | + | ||
49 | +Branch Mode: | ||
50 | +============ | ||
51 | + | ||
52 | +Each branch is assigned a mode - read-write or read-only. This allows | ||
53 | +directories on media mounted read-write to be used in a read-only manner. | ||
54 | + | ||
55 | + | ||
56 | +Whiteouts: | ||
57 | +========== | ||
58 | + | ||
59 | +A whiteout removes a file name from the namespace. Whiteouts are needed when | ||
60 | +one attempts to remove a file on a read-only branch. | ||
61 | + | ||
62 | +Suppose we have a two-branch union, where branch 0 is read-write and branch | ||
63 | +1 is read-only. And a file 'foo' on branch 1: | ||
64 | + | ||
65 | +./b0/ | ||
66 | +./b1/ | ||
67 | +./b1/foo | ||
68 | + | ||
69 | +The unified view would simply be: | ||
70 | + | ||
71 | +./union/ | ||
72 | +./union/foo | ||
73 | + | ||
74 | +Since 'foo' is stored on a read-only branch, it cannot be removed. A | ||
75 | +whiteout is used to remove the name 'foo' from the unified namespace. Again, | ||
76 | +since branch 1 is read-only, the whiteout cannot be created there. So, we | ||
77 | +try on a higher priority (lower numerically) branch and create the whiteout | ||
78 | +there. | ||
79 | + | ||
80 | +./b0/ | ||
81 | +./b0/.wh.foo | ||
82 | +./b1/ | ||
83 | +./b1/foo | ||
84 | + | ||
85 | +Later, when Unionfs traverses branches (due to lookup or readdir), it | ||
86 | +eliminate 'foo' from the namespace (as well as the whiteout itself.) | ||
87 | + | ||
88 | + | ||
89 | +Duplicate Elimination: | ||
90 | +====================== | ||
91 | + | ||
92 | +It is possible for files on different branches to have the same name. | ||
93 | +Unionfs then has to select which instance of the file to show to the user. | ||
94 | +Given the fact that each branch has a priority associated with it, the | ||
95 | +simplest solution is to take the instance from the highest priority | ||
96 | +(numerically lowest value) and "hide" the others. | ||
97 | + | ||
98 | + | ||
99 | +Copyup: | ||
100 | +======= | ||
101 | + | ||
102 | +When a change is made to the contents of a file's data or meta-data, they | ||
103 | +have to be stored somewhere. The best way is to create a copy of the | ||
104 | +original file on a branch that is writable, and then redirect the write | ||
105 | +though to this copy. The copy must be made on a higher priority branch so | ||
106 | +that lookup and readdir return this newer "version" of the file rather than | ||
107 | +the original (see duplicate elimination). | ||
108 | + | ||
109 | + | ||
110 | +For more information, see <http://unionfs.filesystems.org/>. | ||
111 | diff --git a/Documentation/filesystems/unionfs/issues.txt b/Documentation/filesystems/unionfs/issues.txt | ||
112 | new file mode 100644 | ||
113 | index 0000000..a434fee | ||
114 | --- /dev/null | ||
115 | +++ b/Documentation/filesystems/unionfs/issues.txt | ||
116 | @@ -0,0 +1,39 @@ | ||
117 | +KNOWN Unionfs 2.0 ISSUES: | ||
118 | +========================= | ||
119 | + | ||
120 | +1. The NFS server returns -EACCES for read-only exports, instead of -EROFS. | ||
121 | + This means we can't reliably detect a read-only NFS export. | ||
122 | + | ||
123 | +2. Modifying a Unionfs branch directly, while the union is mounted, is | ||
124 | + currently unsupported. We have tested Unionfs under such conditions, and | ||
125 | + fixed any bugs we found (Unionfs comes with an extensive regression test | ||
126 | + suite). However, it may still be possible that changes made to lower | ||
127 | + branches directly could cause cache incoherency which, in the worst case, | ||
128 | + may case an oops. We are currently addressing this problem for Unionfs | ||
129 | + and also generically for all stackable file systems, by handing mmap and | ||
130 | + introducing small VFS/MM changes that would allow a file system to handle | ||
131 | + cache coherency correctly. | ||
132 | + | ||
133 | + Unionfs 2.0 has a temporary workaround for this. You can force Unionfs | ||
134 | + to increase the superblock generation number, and hence purge all cached | ||
135 | + Unionfs objects, which would then be re-gotten from the lower branches. | ||
136 | + This should ensure cache consistency. To increase the generation number, | ||
137 | + executed the command: | ||
138 | + | ||
139 | + mount -t unionfs -o remount,incgen none MOUNTPOINT | ||
140 | + | ||
141 | + Note that the older way of incrementing the generation number using an | ||
142 | + ioctl, is no longer supported in Unionfs 2.0. Ioctls in general are not | ||
143 | + encouraged. Plus, an ioctl is per-file concept, whereas the generation | ||
144 | + number is a per-file-system concept. Worse, such an ioctl requires an | ||
145 | + open file, which then has to be invalidated by the very nature of the | ||
146 | + generation number increase (read: the old generation increase ioctl was | ||
147 | + pretty racy). | ||
148 | + | ||
149 | +3. Unionfs should not use lookup_one_len() on the underlying f/s as it | ||
150 | + confuses NFS. Currently, unionfs_lookup() passes lookup intents to the | ||
151 | + lower file-system, this eliminates part of the problem. The remaining | ||
152 | + calls to lookup_one_len may need to be changed to pass an intent. | ||
153 | + | ||
154 | + | ||
155 | +For more information, see <http://unionfs.filesystems.org/>. | ||
156 | diff --git a/Documentation/filesystems/unionfs/rename.txt b/Documentation/filesystems/unionfs/rename.txt | ||
157 | new file mode 100644 | ||
158 | index 0000000..e20bb82 | ||
159 | --- /dev/null | ||
160 | +++ b/Documentation/filesystems/unionfs/rename.txt | ||
161 | @@ -0,0 +1,31 @@ | ||
162 | +Rename is a complex beast. The following table shows which rename(2) operations | ||
163 | +should succeed and which should fail. | ||
164 | + | ||
165 | +o: success | ||
166 | +E: error (either unionfs or vfs) | ||
167 | +X: EXDEV | ||
168 | + | ||
169 | +none = file does not exist | ||
170 | +file = file is a file | ||
171 | +dir = file is a empty directory | ||
172 | +child= file is a non-empty directory | ||
173 | +wh = file is a directory containing only whiteouts; this makes it logically | ||
174 | + empty | ||
175 | + | ||
176 | + none file dir child wh | ||
177 | +file o o E E E | ||
178 | +dir o E o E o | ||
179 | +child X E X E X | ||
180 | +wh o E o E o | ||
181 | + | ||
182 | + | ||
183 | +Renaming directories: | ||
184 | +===================== | ||
185 | + | ||
186 | +Whenever a empty (either physically or logically) directory is being renamed, | ||
187 | +the following sequence of events should take place: | ||
188 | + | ||
189 | +1) Remove whiteouts from both source and destination directory | ||
190 | +2) Rename source to destination | ||
191 | +3) Make destination opaque to prevent anything under it from showing up | ||
192 | + | ||
193 | diff --git a/Documentation/filesystems/unionfs/usage.txt b/Documentation/filesystems/unionfs/usage.txt | ||
194 | new file mode 100644 | ||
195 | index 0000000..13fbcea | ||
196 | --- /dev/null | ||
197 | +++ b/Documentation/filesystems/unionfs/usage.txt | ||
198 | @@ -0,0 +1,90 @@ | ||
199 | +Unionfs is a stackable unification file system, which can appear to merge | ||
200 | +the contents of several directories (branches), while keeping their physical | ||
201 | +content separate. Unionfs is useful for unified source tree management, | ||
202 | +merged contents of split CD-ROM, merged separate software package | ||
203 | +directories, data grids, and more. Unionfs allows any mix of read-only and | ||
204 | +read-write branches, as well as insertion and deletion of branches anywhere | ||
205 | +in the fan-out. To maintain Unix semantics, Unionfs handles elimination of | ||
206 | +duplicates, partial-error conditions, and more. | ||
207 | + | ||
208 | +# mount -t unionfs -o branch-option[,union-options[,...]] none MOUNTPOINT | ||
209 | + | ||
210 | +The available branch-option for the mount command is: | ||
211 | + | ||
212 | + dirs=branch[=ro|=rw][:...] | ||
213 | + | ||
214 | +specifies a separated list of which directories compose the union. | ||
215 | +Directories that come earlier in the list have a higher precedence than | ||
216 | +those which come later. Additionally, read-only or read-write permissions of | ||
217 | +the branch can be specified by appending =ro or =rw (default) to each | ||
218 | +directory. | ||
219 | + | ||
220 | +Syntax: | ||
221 | + | ||
222 | + dirs=/branch1[=ro|=rw]:/branch2[=ro|=rw]:...:/branchN[=ro|=rw] | ||
223 | + | ||
224 | +Example: | ||
225 | + | ||
226 | + dirs=/writable_branch=rw:/read-only_branch=ro | ||
227 | + | ||
228 | + | ||
229 | +DYNAMIC BRANCH MANAGEMENT AND REMOUNTS | ||
230 | +====================================== | ||
231 | + | ||
232 | +You can remount a union and change its overall mode, or reconfigure the | ||
233 | +branches, as follows. | ||
234 | + | ||
235 | +To downgrade a union from read-write to read-only: | ||
236 | + | ||
237 | +# mount -t unionfs -o remount,ro none MOUNTPOINT | ||
238 | + | ||
239 | +To upgrade a union from read-only to read-write: | ||
240 | + | ||
241 | +# mount -t unionfs -o remount,rw none MOUNTPOINT | ||
242 | + | ||
243 | +To delete a branch /foo, regardless where it is in the current union: | ||
244 | + | ||
245 | +# mount -t unionfs -o del=/foo none MOUNTPOINT | ||
246 | + | ||
247 | +To insert (add) a branch /foo before /bar: | ||
248 | + | ||
249 | +# mount -t unionfs -o remount,add=/bar:/foo none MOUNTPOINT | ||
250 | + | ||
251 | +To insert (add) a branch /foo (with the "rw" mode flag) before /bar: | ||
252 | + | ||
253 | +# mount -t unionfs -o remount,add=/bar:/foo=rw none MOUNTPOINT | ||
254 | + | ||
255 | +To insert (add) a branch /foo (in "rw" mode) at the very beginning (i.e., a | ||
256 | +new highest-priority branch), you can use the above syntax, or use a short | ||
257 | +hand version as follows: | ||
258 | + | ||
259 | +# mount -t unionfs -o remount,add=/foo none MOUNTPOINT | ||
260 | + | ||
261 | +To append a branch to the very end (new lowest-priority branch): | ||
262 | + | ||
263 | +# mount -t unionfs -o remount,add=:/foo none MOUNTPOINT | ||
264 | + | ||
265 | +To append a branch to the very end (new lowest-priority branch), in | ||
266 | +read-only mode: | ||
267 | + | ||
268 | +# mount -t unionfs -o remount,add=:/foo:ro none MOUNTPOINT | ||
269 | + | ||
270 | +Finally, to change the mode of one existing branch, say /foo, from read-only | ||
271 | +to read-write, and change /bar from read-write to read-only: | ||
272 | + | ||
273 | +# mount -t unionfs -o remount,mode=/foo=rw,mode=/bar=ro none MOUNTPOINT | ||
274 | + | ||
275 | + | ||
276 | +CACHE CONSISTENCY | ||
277 | +================= | ||
278 | + | ||
279 | +If you modify any file on any of the lower branches directly, while there is | ||
280 | +a Unionfs 2.0 mounted above any of those branches, you should tell Unionfs | ||
281 | +to purge its caches and re-get the objects. To do that, you have to | ||
282 | +incremenet the generation number of the superblock using the following | ||
283 | +command: | ||
284 | + | ||
285 | +# mount -t unionfs -o remount,remount,incgen none MOUNTPOINT | ||
286 | + | ||
287 | + | ||
288 | +For more information, see <http://unionfs.filesystems.org/>. | ||
289 | diff --git a/MAINTAINERS b/MAINTAINERS | ||
290 | index 277877a..0b728ac 100644 | ||
291 | --- a/MAINTAINERS | ||
292 | +++ b/MAINTAINERS | ||
293 | @@ -3364,6 +3364,13 @@ L: linux-kernel@vger.kernel.org | ||
294 | W: http://www.kernel.dk | ||
295 | S: Maintained | ||
296 | |||
297 | +UNIONFS | ||
298 | +P: Josef "Jeff" Sipek | ||
299 | +M: jsipek@cs.sunysb.edu | ||
300 | +L: unionfs@filesystems.org | ||
301 | +W: http://unionfs.filesystems.org | ||
302 | +S: Maintained | ||
303 | + | ||
304 | USB ACM DRIVER | ||
305 | P: Oliver Neukum | ||
306 | M: oliver@neukum.name | ||
307 | diff --git a/fs/Kconfig b/fs/Kconfig | ||
308 | index 3c4886b..a8cebe3 100644 | ||
309 | --- a/fs/Kconfig | ||
310 | +++ b/fs/Kconfig | ||
311 | @@ -1034,6 +1034,41 @@ config CONFIGFS_FS | ||
312 | |||
313 | endmenu | ||
314 | |||
315 | +menu "Layered filesystems" | ||
316 | + | ||
317 | +config ECRYPT_FS | ||
318 | + tristate "eCrypt filesystem layer support (EXPERIMENTAL)" | ||
319 | + depends on EXPERIMENTAL && KEYS && CRYPTO && NET | ||
320 | + help | ||
321 | + Encrypted filesystem that operates on the VFS layer. See | ||
322 | + <file:Documentation/ecryptfs.txt> to learn more about | ||
323 | + eCryptfs. Userspace components are required and can be | ||
324 | + obtained from <http://ecryptfs.sf.net>. | ||
325 | + | ||
326 | + To compile this file system support as a module, choose M here: the | ||
327 | + module will be called ecryptfs. | ||
328 | + | ||
329 | +config UNION_FS | ||
330 | + tristate "Union file system (EXPERIMENTAL)" | ||
331 | + depends on SLAB && EXPERIMENTAL | ||
332 | + help | ||
333 | + Unionfs is a stackable unification file system, which appears to | ||
334 | + merge the contents of several directories (branches), while keeping | ||
335 | + their physical content separate. | ||
336 | + | ||
337 | + See <http://unionfs.filesystems.org> for details | ||
338 | + | ||
339 | +config UNION_FS_XATTR | ||
340 | + bool "Unionfs extended attributes" | ||
341 | + depends on UNION_FS | ||
342 | + help | ||
343 | + Extended attributes are name:value pairs associated with inodes by | ||
344 | + the kernel or by users (see the attr(5) manual page). | ||
345 | + | ||
346 | + If unsure, say N. | ||
347 | + | ||
348 | +endmenu | ||
349 | + | ||
350 | menu "Miscellaneous filesystems" | ||
351 | |||
352 | config ADFS_FS | ||
353 | @@ -1086,18 +1121,6 @@ config AFFS_FS | ||
354 | To compile this file system support as a module, choose M here: the | ||
355 | module will be called affs. If unsure, say N. | ||
356 | |||
357 | -config ECRYPT_FS | ||
358 | - tristate "eCrypt filesystem layer support (EXPERIMENTAL)" | ||
359 | - depends on EXPERIMENTAL && KEYS && CRYPTO && NET | ||
360 | - help | ||
361 | - Encrypted filesystem that operates on the VFS layer. See | ||
362 | - <file:Documentation/ecryptfs.txt> to learn more about | ||
363 | - eCryptfs. Userspace components are required and can be | ||
364 | - obtained from <http://ecryptfs.sf.net>. | ||
365 | - | ||
366 | - To compile this file system support as a module, choose M here: the | ||
367 | - module will be called ecryptfs. | ||
368 | - | ||
369 | config HFS_FS | ||
370 | tristate "Apple Macintosh file system support (EXPERIMENTAL)" | ||
371 | depends on BLOCK && EXPERIMENTAL | ||
372 | diff --git a/fs/Makefile b/fs/Makefile | ||
373 | index 9edf411..b490b1a 100644 | ||
374 | --- a/fs/Makefile | ||
375 | +++ b/fs/Makefile | ||
376 | @@ -114,3 +114,4 @@ obj-$(CONFIG_HPPFS) += hppfs/ | ||
377 | obj-$(CONFIG_DEBUG_FS) += debugfs/ | ||
378 | obj-$(CONFIG_OCFS2_FS) += ocfs2/ | ||
379 | obj-$(CONFIG_GFS2_FS) += gfs2/ | ||
380 | +obj-$(CONFIG_UNION_FS) += unionfs/ | ||
381 | diff --git a/fs/drop_caches.c b/fs/drop_caches.c | ||
382 | index 03ea769..6a7aa05 100644 | ||
383 | --- a/fs/drop_caches.c | ||
384 | +++ b/fs/drop_caches.c | ||
385 | @@ -3,6 +3,7 @@ | ||
386 | */ | ||
387 | |||
388 | #include <linux/kernel.h> | ||
389 | +#include <linux/module.h> | ||
390 | #include <linux/mm.h> | ||
391 | #include <linux/fs.h> | ||
392 | #include <linux/writeback.h> | ||
393 | @@ -12,7 +13,7 @@ | ||
394 | /* A global variable is a bit ugly, but it keeps the code simple */ | ||
395 | int sysctl_drop_caches; | ||
396 | |||
397 | -static void drop_pagecache_sb(struct super_block *sb) | ||
398 | +void drop_pagecache_sb(struct super_block *sb) | ||
399 | { | ||
400 | struct inode *inode; | ||
401 | |||
402 | @@ -24,6 +25,7 @@ static void drop_pagecache_sb(struct super_block *sb) | ||
403 | } | ||
404 | spin_unlock(&inode_lock); | ||
405 | } | ||
406 | +EXPORT_SYMBOL(drop_pagecache_sb); | ||
407 | |||
408 | void drop_pagecache(void) | ||
409 | { | ||
410 | diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c | ||
411 | index 1548be2..6655918 100644 | ||
412 | --- a/fs/ecryptfs/inode.c | ||
413 | +++ b/fs/ecryptfs/inode.c | ||
414 | @@ -280,7 +280,9 @@ static struct dentry *ecryptfs_lookup(struct inode *dir, struct dentry *dentry, | ||
415 | int rc = 0; | ||
416 | struct dentry *lower_dir_dentry; | ||
417 | struct dentry *lower_dentry; | ||
418 | + struct dentry *dentry_save; | ||
419 | struct vfsmount *lower_mnt; | ||
420 | + struct vfsmount *mnt_save; | ||
421 | char *encoded_name; | ||
422 | unsigned int encoded_namelen; | ||
423 | struct ecryptfs_crypt_stat *crypt_stat = NULL; | ||
424 | @@ -308,9 +310,13 @@ static struct dentry *ecryptfs_lookup(struct inode *dir, struct dentry *dentry, | ||
425 | } | ||
426 | ecryptfs_printk(KERN_DEBUG, "encoded_name = [%s]; encoded_namelen " | ||
427 | "= [%d]\n", encoded_name, encoded_namelen); | ||
428 | - lower_dentry = lookup_one_len(encoded_name, lower_dir_dentry, | ||
429 | - encoded_namelen - 1); | ||
430 | + dentry_save = nd->dentry; | ||
431 | + mnt_save = nd->mnt; | ||
432 | + lower_dentry = lookup_one_len_nd(encoded_name, lower_dir_dentry, | ||
433 | + (encoded_namelen - 1), nd); | ||
434 | kfree(encoded_name); | ||
435 | + nd->mnt = mnt_save; | ||
436 | + nd->dentry = dentry_save; | ||
437 | if (IS_ERR(lower_dentry)) { | ||
438 | ecryptfs_printk(KERN_ERR, "ERR from lower_dentry\n"); | ||
439 | rc = PTR_ERR(lower_dentry); | ||
440 | diff --git a/fs/namei.c b/fs/namei.c | ||
441 | index ee60cc4..2995fba 100644 | ||
442 | --- a/fs/namei.c | ||
443 | +++ b/fs/namei.c | ||
444 | @@ -1292,8 +1292,8 @@ static struct dentry *lookup_hash(struct nameidata *nd) | ||
445 | return __lookup_hash(&nd->last, nd->dentry, nd); | ||
446 | } | ||
447 | |||
448 | -/* SMP-safe */ | ||
449 | -struct dentry * lookup_one_len(const char * name, struct dentry * base, int len) | ||
450 | +struct dentry *lookup_one_len_nd(const char *name, struct dentry *base, | ||
451 | + int len, struct nameidata *nd) | ||
452 | { | ||
453 | unsigned long hash; | ||
454 | struct qstr this; | ||
455 | @@ -1313,7 +1313,7 @@ struct dentry * lookup_one_len(const char * name, struct dentry * base, int len) | ||
456 | } | ||
457 | this.hash = end_name_hash(hash); | ||
458 | |||
459 | - return __lookup_hash(&this, base, NULL); | ||
460 | + return __lookup_hash(&this, base, nd); | ||
461 | access: | ||
462 | return ERR_PTR(-EACCES); | ||
463 | } | ||
464 | @@ -2758,7 +2758,7 @@ EXPORT_SYMBOL(follow_up); | ||
465 | EXPORT_SYMBOL(get_write_access); /* binfmt_aout */ | ||
466 | EXPORT_SYMBOL(getname); | ||
467 | EXPORT_SYMBOL(lock_rename); | ||
468 | -EXPORT_SYMBOL(lookup_one_len); | ||
469 | +EXPORT_SYMBOL(lookup_one_len_nd); | ||
470 | EXPORT_SYMBOL(page_follow_link_light); | ||
471 | EXPORT_SYMBOL(page_put_link); | ||
472 | EXPORT_SYMBOL(page_readlink); | ||
473 | diff --git a/fs/unionfs/Makefile b/fs/unionfs/Makefile | ||
474 | new file mode 100644 | ||
475 | index 0000000..e6b2e0c | ||
476 | --- /dev/null | ||
477 | +++ b/fs/unionfs/Makefile | ||
478 | @@ -0,0 +1,7 @@ | ||
479 | +obj-$(CONFIG_UNION_FS) += unionfs.o | ||
480 | + | ||
481 | +unionfs-y := subr.o dentry.o file.o inode.o main.o super.o \ | ||
482 | + branchman.o rdstate.o copyup.o dirhelper.o rename.o \ | ||
483 | + unlink.o lookup.o commonfops.o dirfops.o sioq.o | ||
484 | + | ||
485 | +unionfs-$(CONFIG_UNION_FS_XATTR) += xattr.o | ||
486 | diff --git a/fs/unionfs/branchman.c b/fs/unionfs/branchman.c | ||
487 | new file mode 100644 | ||
488 | index 0000000..6912be9 | ||
489 | --- /dev/null | ||
490 | +++ b/fs/unionfs/branchman.c | ||
491 | @@ -0,0 +1,60 @@ | ||
492 | +/* | ||
493 | + * Copyright (c) 2003-2007 Erez Zadok | ||
494 | + * Copyright (c) 2003-2006 Charles P. Wright | ||
495 | + * Copyright (c) 2005-2007 Josef 'Jeff' Sipek | ||
496 | + * Copyright (c) 2005-2006 Junjiro Okajima | ||
497 | + * Copyright (c) 2005 Arun M. Krishnakumar | ||
498 | + * Copyright (c) 2004-2006 David P. Quigley | ||
499 | + * Copyright (c) 2003-2004 Mohammad Nayyer Zubair | ||
500 | + * Copyright (c) 2003 Puja Gupta | ||
501 | + * Copyright (c) 2003 Harikesavan Krishnan | ||
502 | + * Copyright (c) 2003-2007 Stony Brook University | ||
503 | + * Copyright (c) 2003-2007 The Research Foundation of State University of New York | ||
504 | + * | ||
505 | + * This program is free software; you can redistribute it and/or modify | ||
506 | + * it under the terms of the GNU General Public License version 2 as | ||
507 | + * published by the Free Software Foundation. | ||
508 | + */ | ||
509 | + | ||
510 | +#include "union.h" | ||
511 | + | ||
512 | +/* return to userspace the branch indices containing the file in question | ||
513 | + * | ||
514 | + * We use fd_set and therefore we are limited to the number of the branches | ||
515 | + * to FD_SETSIZE, which is currently 1024 - plenty for most people | ||
516 | + */ | ||
517 | +int unionfs_ioctl_queryfile(struct file *file, unsigned int cmd, | ||
518 | + unsigned long arg) | ||
519 | +{ | ||
520 | + int err = 0; | ||
521 | + fd_set branchlist; | ||
522 | + | ||
523 | + int bstart = 0, bend = 0, bindex = 0; | ||
524 | + struct dentry *dentry, *hidden_dentry; | ||
525 | + | ||
526 | + dentry = file->f_dentry; | ||
527 | + unionfs_lock_dentry(dentry); | ||
528 | + if ((err = unionfs_partial_lookup(dentry))) | ||
529 | + goto out; | ||
530 | + bstart = dbstart(dentry); | ||
531 | + bend = dbend(dentry); | ||
532 | + | ||
533 | + FD_ZERO(&branchlist); | ||
534 | + | ||
535 | + for (bindex = bstart; bindex <= bend; bindex++) { | ||
536 | + hidden_dentry = unionfs_lower_dentry_idx(dentry, bindex); | ||
537 | + if (!hidden_dentry) | ||
538 | + continue; | ||
539 | + if (hidden_dentry->d_inode) | ||
540 | + FD_SET(bindex, &branchlist); | ||
541 | + } | ||
542 | + | ||
543 | + err = copy_to_user((void __user *)arg, &branchlist, sizeof(fd_set)); | ||
544 | + if (err) | ||
545 | + err = -EFAULT; | ||
546 | + | ||
547 | +out: | ||
548 | + unionfs_unlock_dentry(dentry); | ||
549 | + return err < 0 ? err : bend; | ||
550 | +} | ||
551 | + | ||
552 | diff --git a/fs/unionfs/commonfops.c b/fs/unionfs/commonfops.c | ||
553 | new file mode 100644 | ||
554 | index 0000000..c9df99d | ||
555 | --- /dev/null | ||
556 | +++ b/fs/unionfs/commonfops.c | ||
557 | @@ -0,0 +1,687 @@ | ||
558 | +/* | ||
559 | + * Copyright (c) 2003-2007 Erez Zadok | ||
560 | + * Copyright (c) 2003-2006 Charles P. Wright | ||
561 | + * Copyright (c) 2005-2007 Josef 'Jeff' Sipek | ||
562 | + * Copyright (c) 2005-2006 Junjiro Okajima | ||
563 | + * Copyright (c) 2005 Arun M. Krishnakumar | ||
564 | + * Copyright (c) 2004-2006 David P. Quigley | ||
565 | + * Copyright (c) 2003-2004 Mohammad Nayyer Zubair | ||
566 | + * Copyright (c) 2003 Puja Gupta | ||
567 | + * Copyright (c) 2003 Harikesavan Krishnan | ||
568 | + * Copyright (c) 2003-2007 Stony Brook University | ||
569 | + * Copyright (c) 2003-2007 The Research Foundation of State University of New York | ||
570 | + * | ||
571 | + * This program is free software; you can redistribute it and/or modify | ||
572 | + * it under the terms of the GNU General Public License version 2 as | ||
573 | + * published by the Free Software Foundation. | ||
574 | + */ | ||
575 | + | ||
576 | +#include "union.h" | ||
577 | + | ||
578 | +/* 1) Copyup the file | ||
579 | + * 2) Rename the file to '.unionfs<original inode#><counter>' - obviously | ||
580 | + * stolen from NFS's silly rename | ||
581 | + */ | ||
582 | +static int copyup_deleted_file(struct file *file, struct dentry *dentry, | ||
583 | + int bstart, int bindex) | ||
584 | +{ | ||
585 | + static unsigned int counter; | ||
586 | + const int i_inosize = sizeof(dentry->d_inode->i_ino) * 2; | ||
587 | + const int countersize = sizeof(counter) * 2; | ||
588 | + const int nlen = sizeof(".unionfs") + i_inosize + countersize - 1; | ||
589 | + char name[nlen + 1]; | ||
590 | + | ||
591 | + int err; | ||
592 | + struct dentry *tmp_dentry = NULL; | ||
593 | + struct dentry *hidden_dentry; | ||
594 | + struct dentry *hidden_dir_dentry = NULL; | ||
595 | + | ||
596 | + hidden_dentry = unionfs_lower_dentry_idx(dentry, bstart); | ||
597 | + | ||
598 | + sprintf(name, ".unionfs%*.*lx", | ||
599 | + i_inosize, i_inosize, hidden_dentry->d_inode->i_ino); | ||
600 | + | ||
601 | + /* | ||
602 | + * Loop, looking for an unused temp name to copyup to. | ||
603 | + * | ||
604 | + * It's somewhat silly that we look for a free temp tmp name in the | ||
605 | + * source branch (bstart) instead of the dest branch (bindex), where | ||
606 | + * the final name will be created. We _will_ catch it if somehow | ||
607 | + * the name exists in the dest branch, but it'd be nice to catch it | ||
608 | + * sooner than later. | ||
609 | + */ | ||
610 | + tmp_dentry = NULL; | ||
611 | + do { | ||
612 | + char *suffix = name + nlen - countersize; | ||
613 | + | ||
614 | + dput(tmp_dentry); | ||
615 | + counter++; | ||
616 | + sprintf(suffix, "%*.*x", countersize, countersize, counter); | ||
617 | + | ||
618 | + printk(KERN_DEBUG "unionfs: trying to rename %s to %s\n", | ||
619 | + dentry->d_name.name, name); | ||
620 | + | ||
621 | + tmp_dentry = lookup_one_len(name, hidden_dentry->d_parent, | ||
622 | + UNIONFS_TMPNAM_LEN); | ||
623 | + if (IS_ERR(tmp_dentry)) { | ||
624 | + err = PTR_ERR(tmp_dentry); | ||
625 | + goto out; | ||
626 | + } | ||
627 | + /* don't dput here because of do-while condition eval order */ | ||
628 | + } while (tmp_dentry->d_inode != NULL); /* need negative dentry */ | ||
629 | + dput(tmp_dentry); | ||
630 | + | ||
631 | + err = copyup_named_file(dentry->d_parent->d_inode, file, name, bstart, | ||
632 | + bindex, file->f_dentry->d_inode->i_size); | ||
633 | + if (err) | ||
634 | + goto out; | ||
635 | + | ||
636 | + /* bring it to the same state as an unlinked file */ | ||
637 | + hidden_dentry = unionfs_lower_dentry_idx(dentry, dbstart(dentry)); | ||
638 | + hidden_dir_dentry = lock_parent(hidden_dentry); | ||
639 | + err = vfs_unlink(hidden_dir_dentry->d_inode, hidden_dentry); | ||
640 | + unlock_dir(hidden_dir_dentry); | ||
641 | + | ||
642 | +out: | ||
643 | + return err; | ||
644 | +} | ||
645 | + | ||
646 | +/* | ||
647 | + * Find new index of matching branch with an open file, since branches could | ||
648 | + * have been added/deleted causing the one with open files to shift. | ||
649 | + * | ||
650 | + * @file: current file whose branches may have changed | ||
651 | + * @bindex: index of branch within current file (could be old branch) | ||
652 | + * @new_sb: the new superblock which may have new branch IDs | ||
653 | + * Returns index of newly found branch (0 or greater), -1 otherwise. | ||
654 | + */ | ||
655 | +static int find_new_branch_index(struct file *file, int bindex, | ||
656 | + struct super_block *new_sb) | ||
657 | +{ | ||
658 | + int old_branch_id = UNIONFS_F(file)->saved_branch_ids[bindex]; | ||
659 | + int i; | ||
660 | + | ||
661 | + for (i = 0; i < sbmax(new_sb); i++) | ||
662 | + if (old_branch_id == branch_id(new_sb, i)) | ||
663 | + return i; | ||
664 | + /* | ||
665 | + * XXX: maybe we should BUG_ON if not found new branch index? | ||
666 | + * (really that should never happen). | ||
667 | + */ | ||
668 | + return -1; | ||
669 | +} | ||
670 | + | ||
671 | +/* put all references held by upper struct file and free lower file pointer | ||
672 | + * array | ||
673 | + */ | ||
674 | +static void cleanup_file(struct file *file) | ||
675 | +{ | ||
676 | + int bindex, bstart, bend; | ||
677 | + struct file **lf; | ||
678 | + struct super_block *sb = file->f_dentry->d_sb; | ||
679 | + | ||
680 | + lf = UNIONFS_F(file)->lower_files; | ||
681 | + bstart = fbstart(file); | ||
682 | + bend = fbend(file); | ||
683 | + | ||
684 | + for (bindex = bstart; bindex <= bend; bindex++) { | ||
685 | + if (unionfs_lower_file_idx(file, bindex)) { | ||
686 | + int i; /* holds (possibly) updated branch index */ | ||
687 | + i = find_new_branch_index(file, bindex, sb); | ||
688 | + if (i < 0) | ||
689 | + printk(KERN_ERR "unionfs: no supberlock for file %p\n", | ||
690 | + file); | ||
691 | + else { | ||
692 | + unionfs_read_lock(sb); | ||
693 | + branchput(sb, i); | ||
694 | + unionfs_read_unlock(sb); | ||
695 | + /* XXX: is it correct to use sb->s_root here? */ | ||
696 | + unionfs_mntput(sb->s_root, i); | ||
697 | + /* XXX: mntget b/c fput below will call mntput */ | ||
698 | + unionfs_mntget(sb->s_root, bindex); | ||
699 | + } | ||
700 | + fput(unionfs_lower_file_idx(file, bindex)); | ||
701 | + } | ||
702 | + } | ||
703 | + | ||
704 | + UNIONFS_F(file)->lower_files = NULL; | ||
705 | + kfree(lf); | ||
706 | + kfree(UNIONFS_F(file)->saved_branch_ids); | ||
707 | + /* set to NULL because caller needs to know if to kfree on error */ | ||
708 | + UNIONFS_F(file)->saved_branch_ids = NULL; | ||
709 | +} | ||
710 | + | ||
711 | +/* open all lower files for a given file */ | ||
712 | +static int open_all_files(struct file *file) | ||
713 | +{ | ||
714 | + int bindex, bstart, bend, err = 0; | ||
715 | + struct file *hidden_file; | ||
716 | + struct dentry *hidden_dentry; | ||
717 | + struct dentry *dentry = file->f_dentry; | ||
718 | + struct super_block *sb = dentry->d_sb; | ||
719 | + | ||
720 | + bstart = dbstart(dentry); | ||
721 | + bend = dbend(dentry); | ||
722 | + | ||
723 | + for (bindex = bstart; bindex <= bend; bindex++) { | ||
724 | + hidden_dentry = unionfs_lower_dentry_idx(dentry, bindex); | ||
725 | + if (!hidden_dentry) | ||
726 | + continue; | ||
727 | + | ||
728 | + dget(hidden_dentry); | ||
729 | + unionfs_mntget(dentry, bindex); | ||
730 | + unionfs_read_lock(sb); | ||
731 | + branchget(sb, bindex); | ||
732 | + unionfs_read_unlock(sb); | ||
733 | + | ||
734 | + hidden_file = dentry_open(hidden_dentry, | ||
735 | + unionfs_lower_mnt_idx(dentry, bindex), | ||
736 | + file->f_flags); | ||
737 | + if (IS_ERR(hidden_file)) { | ||
738 | + err = PTR_ERR(hidden_file); | ||
739 | + goto out; | ||
740 | + } else | ||
741 | + unionfs_set_lower_file_idx(file, bindex, hidden_file); | ||
742 | + } | ||
743 | +out: | ||
744 | + return err; | ||
745 | +} | ||
746 | + | ||
747 | +/* open the highest priority file for a given upper file */ | ||
748 | +static int open_highest_file(struct file *file, int willwrite) | ||
749 | +{ | ||
750 | + int bindex, bstart, bend, err = 0; | ||
751 | + struct file *hidden_file; | ||
752 | + struct dentry *hidden_dentry; | ||
753 | + | ||
754 | + struct dentry *dentry = file->f_dentry; | ||
755 | + struct inode *parent_inode = dentry->d_parent->d_inode; | ||
756 | + struct super_block *sb = dentry->d_sb; | ||
757 | + size_t inode_size = dentry->d_inode->i_size; | ||
758 | + | ||
759 | + bstart = dbstart(dentry); | ||
760 | + bend = dbend(dentry); | ||
761 | + | ||
762 | + hidden_dentry = unionfs_lower_dentry(dentry); | ||
763 | + if (willwrite && IS_WRITE_FLAG(file->f_flags) && is_robranch(dentry)) { | ||
764 | + for (bindex = bstart - 1; bindex >= 0; bindex--) { | ||
765 | + err = copyup_file(parent_inode, file, bstart, bindex, | ||
766 | + inode_size); | ||
767 | + if (!err) | ||
768 | + break; | ||
769 | + } | ||
770 | + atomic_set(&UNIONFS_F(file)->generation, | ||
771 | + atomic_read(&UNIONFS_I(dentry->d_inode)->generation)); | ||
772 | + goto out; | ||
773 | + } | ||
774 | + | ||
775 | + dget(hidden_dentry); | ||
776 | + unionfs_mntget(dentry, bstart); | ||
777 | + unionfs_read_lock(sb); | ||
778 | + branchget(sb, bstart); | ||
779 | + unionfs_read_unlock(sb); | ||
780 | + hidden_file = dentry_open(hidden_dentry, | ||
781 | + unionfs_lower_mnt_idx(dentry, bstart), file->f_flags); | ||
782 | + if (IS_ERR(hidden_file)) { | ||
783 | + err = PTR_ERR(hidden_file); | ||
784 | + goto out; | ||
785 | + } | ||
786 | + unionfs_set_lower_file(file, hidden_file); | ||
787 | + /* Fix up the position. */ | ||
788 | + hidden_file->f_pos = file->f_pos; | ||
789 | + | ||
790 | + memcpy(&hidden_file->f_ra, &file->f_ra, sizeof(struct file_ra_state)); | ||
791 | +out: | ||
792 | + return err; | ||
793 | +} | ||
794 | + | ||
795 | +static int do_delayed_copyup(struct file *file, struct dentry *dentry) | ||
796 | +{ | ||
797 | + int bindex, bstart, bend, err = 0; | ||
798 | + struct inode *parent_inode = dentry->d_parent->d_inode; | ||
799 | + loff_t inode_size = file->f_dentry->d_inode->i_size; | ||
800 | + | ||
801 | + bstart = fbstart(file); | ||
802 | + bend = fbend(file); | ||
803 | + | ||
804 | + BUG_ON(!S_ISREG(file->f_dentry->d_inode->i_mode)); | ||
805 | + | ||
806 | + for (bindex = bstart - 1; bindex >= 0; bindex--) { | ||
807 | + if (!d_deleted(file->f_dentry)) | ||
808 | + err = copyup_file(parent_inode, file, bstart, | ||
809 | + bindex, inode_size); | ||
810 | + else | ||
811 | + err = copyup_deleted_file(file, dentry, bstart, bindex); | ||
812 | + | ||
813 | + if (!err) | ||
814 | + break; | ||
815 | + } | ||
816 | + if (!err && (bstart > fbstart(file))) { | ||
817 | + bend = fbend(file); | ||
818 | + for (bindex = bstart; bindex <= bend; bindex++) { | ||
819 | + if (unionfs_lower_file_idx(file, bindex)) { | ||
820 | + unionfs_read_lock(dentry->d_sb); | ||
821 | + branchput(dentry->d_sb, bindex); | ||
822 | + unionfs_read_unlock(dentry->d_sb); | ||
823 | + fput(unionfs_lower_file_idx(file, bindex)); | ||
824 | + unionfs_set_lower_file_idx(file, bindex, NULL); | ||
825 | + } | ||
826 | + } | ||
827 | + fbend(file) = bend; | ||
828 | + } | ||
829 | + return err; | ||
830 | +} | ||
831 | + | ||
832 | +/* | ||
833 | + * Revalidate the struct file | ||
834 | + * @file: file to revalidate | ||
835 | + * @willwrite: 1 if caller may cause changes to the file; 0 otherwise. | ||
836 | + */ | ||
837 | +int unionfs_file_revalidate(struct file *file, int willwrite) | ||
838 | +{ | ||
839 | + struct super_block *sb; | ||
840 | + struct dentry *dentry; | ||
841 | + int sbgen, fgen, dgen; | ||
842 | + int bstart, bend; | ||
843 | + int size; | ||
844 | + | ||
845 | + int err = 0; | ||
846 | + | ||
847 | + dentry = file->f_dentry; | ||
848 | + unionfs_lock_dentry(dentry); | ||
849 | + sb = dentry->d_sb; | ||
850 | + | ||
851 | + /* first revalidate the dentry inside struct file */ | ||
852 | + if (!__unionfs_d_revalidate_chain(dentry, NULL) && !d_deleted(dentry)) { | ||
853 | + err = -ESTALE; | ||
854 | + goto out_nofree; | ||
855 | + } | ||
856 | + | ||
857 | + sbgen = atomic_read(&UNIONFS_SB(sb)->generation); | ||
858 | + dgen = atomic_read(&UNIONFS_D(dentry)->generation); | ||
859 | + fgen = atomic_read(&UNIONFS_F(file)->generation); | ||
860 | + | ||
861 | + BUG_ON(sbgen > dgen); | ||
862 | + | ||
863 | + /* There are two cases we are interested in. The first is if the | ||
864 | + * generation is lower than the super-block. The second is if someone | ||
865 | + * has copied up this file from underneath us, we also need to refresh | ||
866 | + * things. | ||
867 | + */ | ||
868 | + if (!d_deleted(dentry) && | ||
869 | + (sbgen > fgen || dbstart(dentry) != fbstart(file))) { | ||
870 | + /* First we throw out the existing files. */ | ||
871 | + cleanup_file(file); | ||
872 | + | ||
873 | + /* Now we reopen the file(s) as in unionfs_open. */ | ||
874 | + bstart = fbstart(file) = dbstart(dentry); | ||
875 | + bend = fbend(file) = dbend(dentry); | ||
876 | + | ||
877 | + size = sizeof(struct file *) * sbmax(sb); | ||
878 | + UNIONFS_F(file)->lower_files = kzalloc(size, GFP_KERNEL); | ||
879 | + if (!UNIONFS_F(file)->lower_files) { | ||
880 | + err = -ENOMEM; | ||
881 | + goto out; | ||
882 | + } | ||
883 | + size = sizeof(int) * sbmax(sb); | ||
884 | + UNIONFS_F(file)->saved_branch_ids = kzalloc(size, GFP_KERNEL); | ||
885 | + if (!UNIONFS_F(file)->saved_branch_ids) { | ||
886 | + err = -ENOMEM; | ||
887 | + goto out; | ||
888 | + } | ||
889 | + | ||
890 | + if (S_ISDIR(dentry->d_inode->i_mode)) { | ||
891 | + /* We need to open all the files. */ | ||
892 | + err = open_all_files(file); | ||
893 | + if (err) | ||
894 | + goto out; | ||
895 | + } else { | ||
896 | + /* We only open the highest priority branch. */ | ||
897 | + err = open_highest_file(file, willwrite); | ||
898 | + if (err) | ||
899 | + goto out; | ||
900 | + } | ||
901 | + atomic_set(&UNIONFS_F(file)->generation, | ||
902 | + atomic_read(&UNIONFS_I(dentry->d_inode)-> | ||
903 | + generation)); | ||
904 | + } | ||
905 | + | ||
906 | + /* Copyup on the first write to a file on a readonly branch. */ | ||
907 | + if (willwrite && IS_WRITE_FLAG(file->f_flags) && | ||
908 | + !IS_WRITE_FLAG(unionfs_lower_file(file)->f_flags) && | ||
909 | + is_robranch(dentry)) { | ||
910 | + printk(KERN_DEBUG "Doing delayed copyup of a read-write " | ||
911 | + "file on a read-only branch.\n"); | ||
912 | + err = do_delayed_copyup(file, dentry); | ||
913 | + } | ||
914 | + | ||
915 | +out: | ||
916 | + if (err) { | ||
917 | + kfree(UNIONFS_F(file)->lower_files); | ||
918 | + kfree(UNIONFS_F(file)->saved_branch_ids); | ||
919 | + } | ||
920 | +out_nofree: | ||
921 | + unionfs_unlock_dentry(dentry); | ||
922 | + return err; | ||
923 | +} | ||
924 | + | ||
925 | +/* unionfs_open helper function: open a directory */ | ||
926 | +static int __open_dir(struct inode *inode, struct file *file) | ||
927 | +{ | ||
928 | + struct dentry *hidden_dentry; | ||
929 | + struct file *hidden_file; | ||
930 | + int bindex, bstart, bend; | ||
931 | + | ||
932 | + bstart = fbstart(file) = dbstart(file->f_dentry); | ||
933 | + bend = fbend(file) = dbend(file->f_dentry); | ||
934 | + | ||
935 | + for (bindex = bstart; bindex <= bend; bindex++) { | ||
936 | + hidden_dentry = unionfs_lower_dentry_idx(file->f_dentry, bindex); | ||
937 | + if (!hidden_dentry) | ||
938 | + continue; | ||
939 | + | ||
940 | + dget(hidden_dentry); | ||
941 | + unionfs_mntget(file->f_dentry, bindex); | ||
942 | + hidden_file = dentry_open(hidden_dentry, | ||
943 | + unionfs_lower_mnt_idx(file->f_dentry, bindex), | ||
944 | + file->f_flags); | ||
945 | + if (IS_ERR(hidden_file)) | ||
946 | + return PTR_ERR(hidden_file); | ||
947 | + | ||
948 | + unionfs_set_lower_file_idx(file, bindex, hidden_file); | ||
949 | + | ||
950 | + /* The branchget goes after the open, because otherwise | ||
951 | + * we would miss the reference on release. | ||
952 | + */ | ||
953 | + unionfs_read_lock(inode->i_sb); | ||
954 | + branchget(inode->i_sb, bindex); | ||
955 | + unionfs_read_unlock(inode->i_sb); | ||
956 | + } | ||
957 | + | ||
958 | + return 0; | ||
959 | +} | ||
960 | + | ||
961 | +/* unionfs_open helper function: open a file */ | ||
962 | +static int __open_file(struct inode *inode, struct file *file) | ||
963 | +{ | ||
964 | + struct dentry *hidden_dentry; | ||
965 | + struct file *hidden_file; | ||
966 | + int hidden_flags; | ||
967 | + int bindex, bstart, bend; | ||
968 | + | ||
969 | + hidden_dentry = unionfs_lower_dentry(file->f_dentry); | ||
970 | + hidden_flags = file->f_flags; | ||
971 | + | ||
972 | + bstart = fbstart(file) = dbstart(file->f_dentry); | ||
973 | + bend = fbend(file) = dbend(file->f_dentry); | ||
974 | + | ||
975 | + /* check for the permission for hidden file. If the error is COPYUP_ERR, | ||
976 | + * copyup the file. | ||
977 | + */ | ||
978 | + if (hidden_dentry->d_inode && is_robranch(file->f_dentry)) { | ||
979 | + /* if the open will change the file, copy it up otherwise | ||
980 | + * defer it. | ||
981 | + */ | ||
982 | + if (hidden_flags & O_TRUNC) { | ||
983 | + int size = 0; | ||
984 | + int err = -EROFS; | ||
985 | + | ||
986 | + /* copyup the file */ | ||
987 | + for (bindex = bstart - 1; bindex >= 0; bindex--) { | ||
988 | + err = copyup_file(file->f_dentry->d_parent->d_inode, | ||
989 | + file, bstart, bindex, size); | ||
990 | + if (!err) | ||
991 | + break; | ||
992 | + } | ||
993 | + return err; | ||
994 | + } else | ||
995 | + hidden_flags &= ~(OPEN_WRITE_FLAGS); | ||
996 | + } | ||
997 | + | ||
998 | + dget(hidden_dentry); | ||
999 | + | ||
1000 | + /* dentry_open will decrement mnt refcnt if err. | ||
1001 | + * otherwise fput() will do an mntput() for us upon file close. | ||
1002 | + */ | ||
1003 | + unionfs_mntget(file->f_dentry, bstart); | ||
1004 | + hidden_file = dentry_open(hidden_dentry, | ||
1005 | + unionfs_lower_mnt_idx(file->f_dentry, bstart), | ||
1006 | + hidden_flags); | ||
1007 | + if (IS_ERR(hidden_file)) | ||
1008 | + return PTR_ERR(hidden_file); | ||
1009 | + | ||
1010 | + unionfs_set_lower_file(file, hidden_file); | ||
1011 | + unionfs_read_lock(inode->i_sb); | ||
1012 | + branchget(inode->i_sb, bstart); | ||
1013 | + unionfs_read_unlock(inode->i_sb); | ||
1014 | + | ||
1015 | + return 0; | ||
1016 | +} | ||
1017 | + | ||
1018 | +int unionfs_open(struct inode *inode, struct file *file) | ||
1019 | +{ | ||
1020 | + int err = 0; | ||
1021 | + struct file *hidden_file = NULL; | ||
1022 | + struct dentry *dentry = NULL; | ||
1023 | + int bindex = 0, bstart = 0, bend = 0; | ||
1024 | + int size; | ||
1025 | + | ||
1026 | + unionfs_read_lock(inode->i_sb); | ||
1027 | + file->private_data = kzalloc(sizeof(struct unionfs_file_info), GFP_KERNEL); | ||
1028 | + if (!UNIONFS_F(file)) { | ||
1029 | + err = -ENOMEM; | ||
1030 | + goto out_nofree; | ||
1031 | + } | ||
1032 | + fbstart(file) = -1; | ||
1033 | + fbend(file) = -1; | ||
1034 | + atomic_set(&UNIONFS_F(file)->generation, | ||
1035 | + atomic_read(&UNIONFS_I(inode)->generation)); | ||
1036 | + | ||
1037 | + size = sizeof(struct file *) * sbmax(inode->i_sb); | ||
1038 | + UNIONFS_F(file)->lower_files = kzalloc(size, GFP_KERNEL); | ||
1039 | + if (!UNIONFS_F(file)->lower_files) { | ||
1040 | + err = -ENOMEM; | ||
1041 | + goto out; | ||
1042 | + } | ||
1043 | + size = sizeof(int) * sbmax(inode->i_sb); | ||
1044 | + UNIONFS_F(file)->saved_branch_ids = kzalloc(size, GFP_KERNEL); | ||
1045 | + if (!UNIONFS_F(file)->saved_branch_ids) { | ||
1046 | + err = -ENOMEM; | ||
1047 | + goto out; | ||
1048 | + } | ||
1049 | + | ||
1050 | + dentry = file->f_dentry; | ||
1051 | + unionfs_lock_dentry(dentry); | ||
1052 | + | ||
1053 | + bstart = fbstart(file) = dbstart(dentry); | ||
1054 | + bend = fbend(file) = dbend(dentry); | ||
1055 | + | ||
1056 | + /* increment, so that we can flush appropriately */ | ||
1057 | + atomic_inc(&UNIONFS_I(dentry->d_inode)->totalopens); | ||
1058 | + | ||
1059 | + /* open all directories and make the unionfs file struct point to | ||
1060 | + * these hidden file structs | ||
1061 | + */ | ||
1062 | + if (S_ISDIR(inode->i_mode)) | ||
1063 | + err = __open_dir(inode, file); /* open a dir */ | ||
1064 | + else | ||
1065 | + err = __open_file(inode, file); /* open a file */ | ||
1066 | + | ||
1067 | + /* freeing the allocated resources, and fput the opened files */ | ||
1068 | + if (err) { | ||
1069 | + atomic_dec(&UNIONFS_I(dentry->d_inode)->totalopens); | ||
1070 | + for (bindex = bstart; bindex <= bend; bindex++) { | ||
1071 | + hidden_file = unionfs_lower_file_idx(file, bindex); | ||
1072 | + if (!hidden_file) | ||
1073 | + continue; | ||
1074 | + | ||
1075 | + unionfs_read_lock(file->f_dentry->d_sb); | ||
1076 | + branchput(file->f_dentry->d_sb, bindex); | ||
1077 | + unionfs_read_unlock(file->f_dentry->d_sb); | ||
1078 | + /* fput calls dput for hidden_dentry */ | ||
1079 | + fput(hidden_file); | ||
1080 | + } | ||
1081 | + } | ||
1082 | + | ||
1083 | + unionfs_unlock_dentry(dentry); | ||
1084 | + | ||
1085 | +out: | ||
1086 | + if (err) { | ||
1087 | + kfree(UNIONFS_F(file)->lower_files); | ||
1088 | + kfree(UNIONFS_F(file)->saved_branch_ids); | ||
1089 | + kfree(UNIONFS_F(file)); | ||
1090 | + } | ||
1091 | +out_nofree: | ||
1092 | + unionfs_read_unlock(inode->i_sb); | ||
1093 | + return err; | ||
1094 | +} | ||
1095 | + | ||
1096 | +/* release all lower object references & free the file info structure */ | ||
1097 | +int unionfs_file_release(struct inode *inode, struct file *file) | ||
1098 | +{ | ||
1099 | + struct file *hidden_file = NULL; | ||
1100 | + struct unionfs_file_info *fileinfo = UNIONFS_F(file); | ||
1101 | + struct unionfs_inode_info *inodeinfo = UNIONFS_I(inode); | ||
1102 | + int bindex, bstart, bend; | ||
1103 | + int fgen; | ||
1104 | + | ||
1105 | + unionfs_read_lock(inode->i_sb); | ||
1106 | + /* fput all the hidden files */ | ||
1107 | + fgen = atomic_read(&fileinfo->generation); | ||
1108 | + bstart = fbstart(file); | ||
1109 | + bend = fbend(file); | ||
1110 | + | ||
1111 | + for (bindex = bstart; bindex <= bend; bindex++) { | ||
1112 | + hidden_file = unionfs_lower_file_idx(file, bindex); | ||
1113 | + | ||
1114 | + if (hidden_file) { | ||
1115 | + fput(hidden_file); | ||
1116 | + unionfs_read_lock(inode->i_sb); | ||
1117 | + branchput(inode->i_sb, bindex); | ||
1118 | + unionfs_read_unlock(inode->i_sb); | ||
1119 | + } | ||
1120 | + } | ||
1121 | + kfree(fileinfo->lower_files); | ||
1122 | + kfree(fileinfo->saved_branch_ids); | ||
1123 | + | ||
1124 | + if (fileinfo->rdstate) { | ||
1125 | + fileinfo->rdstate->access = jiffies; | ||
1126 | + printk(KERN_DEBUG "Saving rdstate with cookie %u [%d.%lld]\n", | ||
1127 | + fileinfo->rdstate->cookie, | ||
1128 | + fileinfo->rdstate->bindex, | ||
1129 | + (long long)fileinfo->rdstate->dirpos); | ||
1130 | + spin_lock(&inodeinfo->rdlock); | ||
1131 | + inodeinfo->rdcount++; | ||
1132 | + list_add_tail(&fileinfo->rdstate->cache, | ||
1133 | + &inodeinfo->readdircache); | ||
1134 | + mark_inode_dirty(inode); | ||
1135 | + spin_unlock(&inodeinfo->rdlock); | ||
1136 | + fileinfo->rdstate = NULL; | ||
1137 | + } | ||
1138 | + kfree(fileinfo); | ||
1139 | + unionfs_read_unlock(inode->i_sb); | ||
1140 | + return 0; | ||
1141 | +} | ||
1142 | + | ||
1143 | +/* pass the ioctl to the lower fs */ | ||
1144 | +static long do_ioctl(struct file *file, unsigned int cmd, unsigned long arg) | ||
1145 | +{ | ||
1146 | + struct file *hidden_file; | ||
1147 | + int err; | ||
1148 | + | ||
1149 | + hidden_file = unionfs_lower_file(file); | ||
1150 | + | ||
1151 | + err = security_file_ioctl(hidden_file, cmd, arg); | ||
1152 | + if (err) | ||
1153 | + goto out; | ||
1154 | + | ||
1155 | + err = -ENOTTY; | ||
1156 | + if (!hidden_file || !hidden_file->f_op) | ||
1157 | + goto out; | ||
1158 | + if (hidden_file->f_op->unlocked_ioctl) { | ||
1159 | + err = hidden_file->f_op->unlocked_ioctl(hidden_file, cmd, arg); | ||
1160 | + } else if (hidden_file->f_op->ioctl) { | ||
1161 | + lock_kernel(); | ||
1162 | + err = hidden_file->f_op->ioctl(hidden_file->f_dentry->d_inode, | ||
1163 | + hidden_file, cmd, arg); | ||
1164 | + unlock_kernel(); | ||
1165 | + } | ||
1166 | + | ||
1167 | +out: | ||
1168 | + unionfs_read_unlock(file->f_dentry->d_sb); | ||
1169 | + return err; | ||
1170 | +} | ||
1171 | + | ||
1172 | +long unionfs_ioctl(struct file *file, unsigned int cmd, unsigned long arg) | ||
1173 | +{ | ||
1174 | + long err; | ||
1175 | + | ||
1176 | + unionfs_read_lock(file->f_dentry->d_sb); | ||
1177 | + if ((err = unionfs_file_revalidate(file, 1))) | ||
1178 | + goto out; | ||
1179 | + | ||
1180 | + /* check if asked for local commands */ | ||
1181 | + switch (cmd) { | ||
1182 | + case UNIONFS_IOCTL_INCGEN: | ||
1183 | + /* Increment the superblock generation count */ | ||
1184 | + printk("unionfs: incgen ioctl deprecated; use \"-o remount,incgen\"\n"); | ||
1185 | + err = -ENOSYS; | ||
1186 | + break; | ||
1187 | + | ||
1188 | + case UNIONFS_IOCTL_QUERYFILE: | ||
1189 | + /* Return list of branches containing the given file */ | ||
1190 | + err = unionfs_ioctl_queryfile(file, cmd, arg); | ||
1191 | + break; | ||
1192 | + | ||
1193 | + default: | ||
1194 | + /* pass the ioctl down */ | ||
1195 | + err = do_ioctl(file, cmd, arg); | ||
1196 | + break; | ||
1197 | + } | ||
1198 | + | ||
1199 | +out: | ||
1200 | + return err; | ||
1201 | +} | ||
1202 | + | ||
1203 | +int unionfs_flush(struct file *file, fl_owner_t id) | ||
1204 | +{ | ||
1205 | + int err = 0; | ||
1206 | + struct file *hidden_file = NULL; | ||
1207 | + struct dentry *dentry = file->f_dentry; | ||
1208 | + int bindex, bstart, bend; | ||
1209 | + | ||
1210 | + unionfs_read_lock(file->f_dentry->d_sb); | ||
1211 | + | ||
1212 | + if ((err = unionfs_file_revalidate(file, 1))) | ||
1213 | + goto out; | ||
1214 | + | ||
1215 | + if (!atomic_dec_and_test(&UNIONFS_I(dentry->d_inode)->totalopens)) | ||
1216 | + goto out; | ||
1217 | + | ||
1218 | + unionfs_lock_dentry(dentry); | ||
1219 | + | ||
1220 | + bstart = fbstart(file); | ||
1221 | + bend = fbend(file); | ||
1222 | + for (bindex = bstart; bindex <= bend; bindex++) { | ||
1223 | + hidden_file = unionfs_lower_file_idx(file, bindex); | ||
1224 | + | ||
1225 | + if (hidden_file && hidden_file->f_op && hidden_file->f_op->flush) { | ||
1226 | + err = hidden_file->f_op->flush(hidden_file, id); | ||
1227 | + if (err) | ||
1228 | + goto out_lock; | ||
1229 | + | ||
1230 | + /* if there are no more references to the dentry, dput it */ | ||
1231 | + if (d_deleted(dentry)) { | ||
1232 | + dput(unionfs_lower_dentry_idx(dentry, bindex)); | ||
1233 | + unionfs_set_lower_dentry_idx(dentry, bindex, NULL); | ||
1234 | + } | ||
1235 | + } | ||
1236 | + | ||
1237 | + } | ||
1238 | + | ||
1239 | +out_lock: | ||
1240 | + unionfs_unlock_dentry(dentry); | ||
1241 | +out: | ||
1242 | + unionfs_read_unlock(file->f_dentry->d_sb); | ||
1243 | + return err; | ||
1244 | +} | ||
1245 | diff --git a/fs/unionfs/copyup.c b/fs/unionfs/copyup.c | ||
1246 | new file mode 100644 | ||
1247 | index 0000000..411553a | ||
1248 | --- /dev/null | ||
1249 | +++ b/fs/unionfs/copyup.c | ||
1250 | @@ -0,0 +1,776 @@ | ||
1251 | +/* | ||
1252 | + * Copyright (c) 2003-2007 Erez Zadok | ||
1253 | + * Copyright (c) 2003-2006 Charles P. Wright | ||
1254 | + * Copyright (c) 2005-2007 Josef 'Jeff' Sipek | ||
1255 | + * Copyright (c) 2005-2006 Junjiro Okajima | ||
1256 | + * Copyright (c) 2005 Arun M. Krishnakumar | ||
1257 | + * Copyright (c) 2004-2006 David P. Quigley | ||
1258 | + * Copyright (c) 2003-2004 Mohammad Nayyer Zubair | ||
1259 | + * Copyright (c) 2003 Puja Gupta | ||
1260 | + * Copyright (c) 2003 Harikesavan Krishnan | ||
1261 | + * Copyright (c) 2003-2007 Stony Brook University | ||
1262 | + * Copyright (c) 2003-2007 The Research Foundation of State University of New York* | ||
1263 | + * | ||
1264 | + * This program is free software; you can redistribute it and/or modify | ||
1265 | + * it under the terms of the GNU General Public License version 2 as | ||
1266 | + * published by the Free Software Foundation. | ||
1267 | + */ | ||
1268 | + | ||
1269 | +#include "union.h" | ||
1270 | + | ||
1271 | +static int copyup_named_dentry(struct inode *dir, struct dentry *dentry, | ||
1272 | + int bstart, int new_bindex, const char *name, | ||
1273 | + int namelen, struct file **copyup_file, | ||
1274 | + loff_t len); | ||
1275 | +static struct dentry *create_parents_named(struct inode *dir, | ||
1276 | + struct dentry *dentry, | ||
1277 | + const char *name, int bindex); | ||
1278 | + | ||
1279 | +/* For detailed explanation of copyup see: | ||
1280 | + * Documentation/filesystems/unionfs/concepts.txt | ||
1281 | + */ | ||
1282 | + | ||
1283 | +#ifdef CONFIG_UNION_FS_XATTR | ||
1284 | +/* copyup all extended attrs for a given dentry */ | ||
1285 | +static int copyup_xattrs(struct dentry *old_hidden_dentry, | ||
1286 | + struct dentry *new_hidden_dentry) | ||
1287 | +{ | ||
1288 | + int err = 0; | ||
1289 | + ssize_t list_size = -1; | ||
1290 | + char *name_list = NULL; | ||
1291 | + char *attr_value = NULL; | ||
1292 | + char *name_list_orig = NULL; | ||
1293 | + | ||
1294 | + list_size = vfs_listxattr(old_hidden_dentry, NULL, 0); | ||
1295 | + | ||
1296 | + if (list_size <= 0) { | ||
1297 | + err = list_size; | ||
1298 | + goto out; | ||
1299 | + } | ||
1300 | + | ||
1301 | + name_list = unionfs_xattr_alloc(list_size + 1, XATTR_LIST_MAX); | ||
1302 | + if (!name_list || IS_ERR(name_list)) { | ||
1303 | + err = PTR_ERR(name_list); | ||
1304 | + goto out; | ||
1305 | + } | ||
1306 | + list_size = vfs_listxattr(old_hidden_dentry, name_list, list_size); | ||
1307 | + attr_value = unionfs_xattr_alloc(XATTR_SIZE_MAX, XATTR_SIZE_MAX); | ||
1308 | + if (!attr_value || IS_ERR(attr_value)) { | ||
1309 | + err = PTR_ERR(name_list); | ||
1310 | + goto out; | ||
1311 | + } | ||
1312 | + name_list_orig = name_list; | ||
1313 | + while (*name_list) { | ||
1314 | + ssize_t size; | ||
1315 | + | ||
1316 | + /* Lock here since vfs_getxattr doesn't lock for us */ | ||
1317 | + mutex_lock(&old_hidden_dentry->d_inode->i_mutex); | ||
1318 | + size = vfs_getxattr(old_hidden_dentry, name_list, | ||
1319 | + attr_value, XATTR_SIZE_MAX); | ||
1320 | + mutex_unlock(&old_hidden_dentry->d_inode->i_mutex); | ||
1321 | + if (size < 0) { | ||
1322 | + err = size; | ||
1323 | + goto out; | ||
1324 | + } | ||
1325 | + | ||
1326 | + if (size > XATTR_SIZE_MAX) { | ||
1327 | + err = -E2BIG; | ||
1328 | + goto out; | ||
1329 | + } | ||
1330 | + /* Don't lock here since vfs_setxattr does it for us. */ | ||
1331 | + err = vfs_setxattr(new_hidden_dentry, name_list, attr_value, | ||
1332 | + size, 0); | ||
1333 | + | ||
1334 | + if (err < 0) | ||
1335 | + goto out; | ||
1336 | + name_list += strlen(name_list) + 1; | ||
1337 | + } | ||
1338 | + out: | ||
1339 | + name_list = name_list_orig; | ||
1340 | + | ||
1341 | + if (name_list) | ||
1342 | + unionfs_xattr_free(name_list, list_size + 1); | ||
1343 | + if (attr_value) | ||
1344 | + unionfs_xattr_free(attr_value, XATTR_SIZE_MAX); | ||
1345 | + /* It is no big deal if this fails, we just roll with the punches. */ | ||
1346 | + if (err == -ENOTSUPP || err == -EOPNOTSUPP) | ||
1347 | + err = 0; | ||
1348 | + return err; | ||
1349 | +} | ||
1350 | +#endif /* CONFIG_UNION_FS_XATTR */ | ||
1351 | + | ||
1352 | +/* Determine the mode based on the copyup flags, and the existing dentry. */ | ||
1353 | +static int copyup_permissions(struct super_block *sb, | ||
1354 | + struct dentry *old_hidden_dentry, | ||
1355 | + struct dentry *new_hidden_dentry) | ||
1356 | +{ | ||
1357 | + struct inode *i = old_hidden_dentry->d_inode; | ||
1358 | + struct iattr newattrs; | ||
1359 | + int err; | ||
1360 | + | ||
1361 | + newattrs.ia_atime = i->i_atime; | ||
1362 | + newattrs.ia_mtime = i->i_mtime; | ||
1363 | + newattrs.ia_ctime = i->i_ctime; | ||
1364 | + | ||
1365 | + newattrs.ia_gid = i->i_gid; | ||
1366 | + newattrs.ia_uid = i->i_uid; | ||
1367 | + | ||
1368 | + newattrs.ia_mode = i->i_mode; | ||
1369 | + | ||
1370 | + newattrs.ia_valid = ATTR_CTIME | ATTR_ATIME | ATTR_MTIME | | ||
1371 | + ATTR_ATIME_SET | ATTR_MTIME_SET | ATTR_FORCE | | ||
1372 | + ATTR_GID | ATTR_UID | ATTR_MODE; | ||
1373 | + | ||
1374 | + err = notify_change(new_hidden_dentry, &newattrs); | ||
1375 | + | ||
1376 | + return err; | ||
1377 | +} | ||
1378 | + | ||
1379 | +int copyup_dentry(struct inode *dir, struct dentry *dentry, | ||
1380 | + int bstart, int new_bindex, | ||
1381 | + struct file **copyup_file, loff_t len) | ||
1382 | +{ | ||
1383 | + return copyup_named_dentry(dir, dentry, bstart, new_bindex, | ||
1384 | + dentry->d_name.name, | ||
1385 | + dentry->d_name.len, copyup_file, len); | ||
1386 | +} | ||
1387 | + | ||
1388 | +/* create the new device/file/directory - use copyup_permission to copyup | ||
1389 | + * times, and mode | ||
1390 | + * | ||
1391 | + * if the object being copied up is a regular file, the file is only created, | ||
1392 | + * the contents have to be copied up separately | ||
1393 | + */ | ||
1394 | +static int __copyup_ndentry(struct dentry *old_hidden_dentry, | ||
1395 | + struct dentry *new_hidden_dentry, | ||
1396 | + struct dentry *new_hidden_parent_dentry, | ||
1397 | + char *symbuf) | ||
1398 | +{ | ||
1399 | + int err = 0; | ||
1400 | + umode_t old_mode = old_hidden_dentry->d_inode->i_mode; | ||
1401 | + struct sioq_args args; | ||
1402 | + | ||
1403 | + if (S_ISDIR(old_mode)) { | ||
1404 | + args.mkdir.parent = new_hidden_parent_dentry->d_inode; | ||
1405 | + args.mkdir.dentry = new_hidden_dentry; | ||
1406 | + args.mkdir.mode = old_mode; | ||
1407 | + | ||
1408 | + run_sioq(__unionfs_mkdir, &args); | ||
1409 | + err = args.err; | ||
1410 | + } else if (S_ISLNK(old_mode)) { | ||
1411 | + args.symlink.parent = new_hidden_parent_dentry->d_inode; | ||
1412 | + args.symlink.dentry = new_hidden_dentry; | ||
1413 | + args.symlink.symbuf = symbuf; | ||
1414 | + args.symlink.mode = old_mode; | ||
1415 | + | ||
1416 | + run_sioq(__unionfs_symlink, &args); | ||
1417 | + err = args.err; | ||
1418 | + } else if (S_ISBLK(old_mode) || S_ISCHR(old_mode) || | ||
1419 | + S_ISFIFO(old_mode) || S_ISSOCK(old_mode)) { | ||
1420 | + args.mknod.parent = new_hidden_parent_dentry->d_inode; | ||
1421 | + args.mknod.dentry = new_hidden_dentry; | ||
1422 | + args.mknod.mode = old_mode; | ||
1423 | + args.mknod.dev = old_hidden_dentry->d_inode->i_rdev; | ||
1424 | + | ||
1425 | + run_sioq(__unionfs_mknod, &args); | ||
1426 | + err = args.err; | ||
1427 | + } else if (S_ISREG(old_mode)) { | ||
1428 | + args.create.parent = new_hidden_parent_dentry->d_inode; | ||
1429 | + args.create.dentry = new_hidden_dentry; | ||
1430 | + args.create.mode = old_mode; | ||
1431 | + args.create.nd = NULL; | ||
1432 | + | ||
1433 | + run_sioq(__unionfs_create, &args); | ||
1434 | + err = args.err; | ||
1435 | + } else { | ||
1436 | + printk(KERN_ERR "Unknown inode type %d\n", | ||
1437 | + old_mode); | ||
1438 | + BUG(); | ||
1439 | + } | ||
1440 | + | ||
1441 | + return err; | ||
1442 | +} | ||
1443 | + | ||
1444 | +static int __copyup_reg_data(struct dentry *dentry, | ||
1445 | + struct dentry *new_hidden_dentry, int new_bindex, | ||
1446 | + struct dentry *old_hidden_dentry, int old_bindex, | ||
1447 | + struct file **copyup_file, loff_t len) | ||
1448 | +{ | ||
1449 | + struct super_block *sb = dentry->d_sb; | ||
1450 | + struct file *input_file; | ||
1451 | + struct file *output_file; | ||
1452 | + mm_segment_t old_fs; | ||
1453 | + char *buf = NULL; | ||
1454 | + ssize_t read_bytes, write_bytes; | ||
1455 | + loff_t size; | ||
1456 | + int err = 0; | ||
1457 | + | ||
1458 | + /* open old file */ | ||
1459 | + unionfs_mntget(dentry, old_bindex); | ||
1460 | + unionfs_read_lock(sb); | ||
1461 | + branchget(sb, old_bindex); | ||
1462 | + unionfs_read_unlock(sb); | ||
1463 | + input_file = dentry_open(old_hidden_dentry, | ||
1464 | + unionfs_lower_mnt_idx(dentry, old_bindex), | ||
1465 | + O_RDONLY | O_LARGEFILE); | ||
1466 | + if (IS_ERR(input_file)) { | ||
1467 | + dput(old_hidden_dentry); | ||
1468 | + err = PTR_ERR(input_file); | ||
1469 | + goto out; | ||
1470 | + } | ||
1471 | + if (!input_file->f_op || !input_file->f_op->read) { | ||
1472 | + err = -EINVAL; | ||
1473 | + goto out_close_in; | ||
1474 | + } | ||
1475 | + | ||
1476 | + /* open new file */ | ||
1477 | + dget(new_hidden_dentry); | ||
1478 | + unionfs_mntget(dentry, new_bindex); | ||
1479 | + unionfs_read_lock(sb); | ||
1480 | + branchget(sb, new_bindex); | ||
1481 | + unionfs_read_unlock(sb); | ||
1482 | + output_file = dentry_open(new_hidden_dentry, | ||
1483 | + unionfs_lower_mnt_idx(dentry, new_bindex), | ||
1484 | + O_WRONLY | O_LARGEFILE); | ||
1485 | + if (IS_ERR(output_file)) { | ||
1486 | + err = PTR_ERR(output_file); | ||
1487 | + goto out_close_in2; | ||
1488 | + } | ||
1489 | + if (!output_file->f_op || !output_file->f_op->write) { | ||
1490 | + err = -EINVAL; | ||
1491 | + goto out_close_out; | ||
1492 | + } | ||
1493 | + | ||
1494 | + /* allocating a buffer */ | ||
1495 | + buf = kmalloc(PAGE_SIZE, GFP_KERNEL); | ||
1496 | + if (!buf) { | ||
1497 | + err = -ENOMEM; | ||
1498 | + goto out_close_out; | ||
1499 | + } | ||
1500 | + | ||
1501 | + input_file->f_pos = 0; | ||
1502 | + output_file->f_pos = 0; | ||
1503 | + | ||
1504 | + old_fs = get_fs(); | ||
1505 | + set_fs(KERNEL_DS); | ||
1506 | + | ||
1507 | + size = len; | ||
1508 | + err = 0; | ||
1509 | + do { | ||
1510 | + if (len >= PAGE_SIZE) | ||
1511 | + size = PAGE_SIZE; | ||
1512 | + else if ((len < PAGE_SIZE) && (len > 0)) | ||
1513 | + size = len; | ||
1514 | + | ||
1515 | + len -= PAGE_SIZE; | ||
1516 | + | ||
1517 | + read_bytes = | ||
1518 | + input_file->f_op->read(input_file, | ||
1519 | + (char __user *)buf, size, | ||
1520 | + &input_file->f_pos); | ||
1521 | + if (read_bytes <= 0) { | ||
1522 | + err = read_bytes; | ||
1523 | + break; | ||
1524 | + } | ||
1525 | + | ||
1526 | + write_bytes = | ||
1527 | + output_file->f_op->write(output_file, | ||
1528 | + (char __user *)buf, | ||
1529 | + read_bytes, | ||
1530 | + &output_file->f_pos); | ||
1531 | + if ((write_bytes < 0) || (write_bytes < read_bytes)) { | ||
1532 | + err = write_bytes; | ||
1533 | + break; | ||
1534 | + } | ||
1535 | + } while ((read_bytes > 0) && (len > 0)); | ||
1536 | + | ||
1537 | + set_fs(old_fs); | ||
1538 | + | ||
1539 | + kfree(buf); | ||
1540 | + | ||
1541 | + if (err) | ||
1542 | + goto out_close_out; | ||
1543 | + if (copyup_file) { | ||
1544 | + *copyup_file = output_file; | ||
1545 | + goto out_close_in; | ||
1546 | + } | ||
1547 | + | ||
1548 | +out_close_out: | ||
1549 | + fput(output_file); | ||
1550 | + | ||
1551 | +out_close_in2: | ||
1552 | + unionfs_read_lock(sb); | ||
1553 | + branchput(sb, new_bindex); | ||
1554 | + unionfs_read_unlock(sb); | ||
1555 | + | ||
1556 | +out_close_in: | ||
1557 | + fput(input_file); | ||
1558 | + | ||
1559 | +out: | ||
1560 | + unionfs_read_lock(sb); | ||
1561 | + branchput(sb, old_bindex); | ||
1562 | + unionfs_read_unlock(sb); | ||
1563 | + | ||
1564 | + return err; | ||
1565 | +} | ||
1566 | + | ||
1567 | +/* dput the lower references for old and new dentry & clear a lower dentry | ||
1568 | + * pointer | ||
1569 | + */ | ||
1570 | +static void __clear(struct dentry *dentry, struct dentry *old_hidden_dentry, | ||
1571 | + int old_bstart, int old_bend, | ||
1572 | + struct dentry *new_hidden_dentry, int new_bindex) | ||
1573 | +{ | ||
1574 | + /* get rid of the hidden dentry and all its traces */ | ||
1575 | + unionfs_set_lower_dentry_idx(dentry, new_bindex, NULL); | ||
1576 | + set_dbstart(dentry, old_bstart); | ||
1577 | + set_dbend(dentry, old_bend); | ||
1578 | + | ||
1579 | + dput(new_hidden_dentry); | ||
1580 | + dput(old_hidden_dentry); | ||
1581 | +} | ||
1582 | + | ||
1583 | +/* copy up a dentry to a file of specified name */ | ||
1584 | +static int copyup_named_dentry(struct inode *dir, struct dentry *dentry, | ||
1585 | + int bstart, int new_bindex, const char *name, | ||
1586 | + int namelen, struct file **copyup_file, | ||
1587 | + loff_t len) | ||
1588 | +{ | ||
1589 | + struct dentry *new_hidden_dentry; | ||
1590 | + struct dentry *old_hidden_dentry = NULL; | ||
1591 | + struct super_block *sb; | ||
1592 | + int err = 0; | ||
1593 | + int old_bindex; | ||
1594 | + int old_bstart; | ||
1595 | + int old_bend; | ||
1596 | + struct dentry *new_hidden_parent_dentry = NULL; | ||
1597 | + mm_segment_t oldfs; | ||
1598 | + char *symbuf = NULL; | ||
1599 | + | ||
1600 | + verify_locked(dentry); | ||
1601 | + | ||
1602 | + old_bindex = bstart; | ||
1603 | + old_bstart = dbstart(dentry); | ||
1604 | + old_bend = dbend(dentry); | ||
1605 | + | ||
1606 | + BUG_ON(new_bindex < 0); | ||
1607 | + BUG_ON(new_bindex >= old_bindex); | ||
1608 | + | ||
1609 | + sb = dir->i_sb; | ||
1610 | + | ||
1611 | + if ((err = is_robranch_super(sb, new_bindex))) | ||
1612 | + goto out; | ||
1613 | + | ||
1614 | + /* Create the directory structure above this dentry. */ | ||
1615 | + new_hidden_dentry = create_parents_named(dir, dentry, name, new_bindex); | ||
1616 | + if (IS_ERR(new_hidden_dentry)) { | ||
1617 | + err = PTR_ERR(new_hidden_dentry); | ||
1618 | + goto out; | ||
1619 | + } | ||
1620 | + | ||
1621 | + old_hidden_dentry = unionfs_lower_dentry_idx(dentry, old_bindex); | ||
1622 | + /* we conditionally dput this old_hidden_dentry at end of function */ | ||
1623 | + dget(old_hidden_dentry); | ||
1624 | + | ||
1625 | + /* For symlinks, we must read the link before we lock the directory. */ | ||
1626 | + if (S_ISLNK(old_hidden_dentry->d_inode->i_mode)) { | ||
1627 | + | ||
1628 | + symbuf = kmalloc(PATH_MAX, GFP_KERNEL); | ||
1629 | + if (!symbuf) { | ||
1630 | + __clear(dentry, old_hidden_dentry, | ||
1631 | + old_bstart, old_bend, | ||
1632 | + new_hidden_dentry, new_bindex); | ||
1633 | + err = -ENOMEM; | ||
1634 | + goto out_free; | ||
1635 | + } | ||
1636 | + | ||
1637 | + oldfs = get_fs(); | ||
1638 | + set_fs(KERNEL_DS); | ||
1639 | + err = old_hidden_dentry->d_inode->i_op->readlink( | ||
1640 | + old_hidden_dentry, | ||
1641 | + (char __user *)symbuf, | ||
1642 | + PATH_MAX); | ||
1643 | + set_fs(oldfs); | ||
1644 | + if (err) { | ||
1645 | + __clear(dentry, old_hidden_dentry, | ||
1646 | + old_bstart, old_bend, | ||
1647 | + new_hidden_dentry, new_bindex); | ||
1648 | + goto out_free; | ||
1649 | + } | ||
1650 | + symbuf[err] = '\0'; | ||
1651 | + } | ||
1652 | + | ||
1653 | + /* Now we lock the parent, and create the object in the new branch. */ | ||
1654 | + new_hidden_parent_dentry = lock_parent(new_hidden_dentry); | ||
1655 | + | ||
1656 | + /* create the new inode */ | ||
1657 | + err = __copyup_ndentry(old_hidden_dentry, new_hidden_dentry, | ||
1658 | + new_hidden_parent_dentry, symbuf); | ||
1659 | + | ||
1660 | + if (err) { | ||
1661 | + __clear(dentry, old_hidden_dentry, | ||
1662 | + old_bstart, old_bend, | ||
1663 | + new_hidden_dentry, new_bindex); | ||
1664 | + goto out_unlock; | ||
1665 | + } | ||
1666 | + | ||
1667 | + /* We actually copyup the file here. */ | ||
1668 | + if (S_ISREG(old_hidden_dentry->d_inode->i_mode)) | ||
1669 | + err = __copyup_reg_data(dentry, new_hidden_dentry, new_bindex, | ||
1670 | + old_hidden_dentry, old_bindex, copyup_file, len); | ||
1671 | + if (err) | ||
1672 | + goto out_unlink; | ||
1673 | + | ||
1674 | + /* Set permissions. */ | ||
1675 | + if ((err = copyup_permissions(sb, old_hidden_dentry, new_hidden_dentry))) | ||
1676 | + goto out_unlink; | ||
1677 | + | ||
1678 | +#ifdef CONFIG_UNION_FS_XATTR | ||
1679 | + /* Selinux uses extended attributes for permissions. */ | ||
1680 | + if ((err = copyup_xattrs(old_hidden_dentry, new_hidden_dentry))) | ||
1681 | + goto out_unlink; | ||
1682 | +#endif | ||
1683 | + | ||
1684 | + /* do not allow files getting deleted to be reinterposed */ | ||
1685 | + if (!d_deleted(dentry)) | ||
1686 | + unionfs_reinterpose(dentry); | ||
1687 | + | ||
1688 | + goto out_unlock; | ||
1689 | + /****/ | ||
1690 | + | ||
1691 | +out_unlink: | ||
1692 | + /* copyup failed, because we possibly ran out of space or | ||
1693 | + * quota, or something else happened so let's unlink; we don't | ||
1694 | + * really care about the return value of vfs_unlink | ||
1695 | + */ | ||
1696 | + vfs_unlink(new_hidden_parent_dentry->d_inode, new_hidden_dentry); | ||
1697 | + | ||
1698 | + if (copyup_file) { | ||
1699 | + /* need to close the file */ | ||
1700 | + | ||
1701 | + fput(*copyup_file); | ||
1702 | + unionfs_read_lock(sb); | ||
1703 | + branchput(sb, new_bindex); | ||
1704 | + unionfs_read_unlock(sb); | ||
1705 | + } | ||
1706 | + | ||
1707 | + /* | ||
1708 | + * TODO: should we reset the error to something like -EIO? | ||
1709 | + * | ||
1710 | + * If we don't reset, the user may get some non-sensical errors, but | ||
1711 | + * on the other hand, if we reset to EIO, we guarantee that the user | ||
1712 | + * will get a "confusing" error message. | ||
1713 | + */ | ||
1714 | + | ||
1715 | +out_unlock: | ||
1716 | + unlock_dir(new_hidden_parent_dentry); | ||
1717 | + | ||
1718 | +out_free: | ||
1719 | + /* | ||
1720 | + * If old_hidden_dentry was a directory, we need to dput it. If it | ||
1721 | + * was a file, then it was already dput indirectly by other | ||
1722 | + * functions we call ablve which operate on regular files. | ||
1723 | + */ | ||
1724 | + if (old_hidden_dentry && old_hidden_dentry->d_inode && | ||
1725 | + S_ISDIR(old_hidden_dentry->d_inode->i_mode)) | ||
1726 | + dput(old_hidden_dentry); | ||
1727 | + kfree(symbuf); | ||
1728 | + | ||
1729 | +out: | ||
1730 | + return err; | ||
1731 | +} | ||
1732 | + | ||
1733 | +/* This function creates a copy of a file represented by 'file' which currently | ||
1734 | + * resides in branch 'bstart' to branch 'new_bindex.' The copy will be named | ||
1735 | + * "name". | ||
1736 | + */ | ||
1737 | +int copyup_named_file(struct inode *dir, struct file *file, char *name, | ||
1738 | + int bstart, int new_bindex, loff_t len) | ||
1739 | +{ | ||
1740 | + int err = 0; | ||
1741 | + struct file *output_file = NULL; | ||
1742 | + | ||
1743 | + err = copyup_named_dentry(dir, file->f_dentry, bstart, | ||
1744 | + new_bindex, name, strlen(name), &output_file, | ||
1745 | + len); | ||
1746 | + if (!err) { | ||
1747 | + fbstart(file) = new_bindex; | ||
1748 | + unionfs_set_lower_file_idx(file, new_bindex, output_file); | ||
1749 | + } | ||
1750 | + | ||
1751 | + return err; | ||
1752 | +} | ||
1753 | + | ||
1754 | +/* This function creates a copy of a file represented by 'file' which currently | ||
1755 | + * resides in branch 'bstart' to branch 'new_bindex'. | ||
1756 | + */ | ||
1757 | +int copyup_file(struct inode *dir, struct file *file, int bstart, | ||
1758 | + int new_bindex, loff_t len) | ||
1759 | +{ | ||
1760 | + int err = 0; | ||
1761 | + struct file *output_file = NULL; | ||
1762 | + | ||
1763 | + err = copyup_dentry(dir, file->f_dentry, bstart, new_bindex, | ||
1764 | + &output_file, len); | ||
1765 | + if (!err) { | ||
1766 | + fbstart(file) = new_bindex; | ||
1767 | + unionfs_set_lower_file_idx(file, new_bindex, output_file); | ||
1768 | + } | ||
1769 | + | ||
1770 | + return err; | ||
1771 | +} | ||
1772 | + | ||
1773 | +/* This function replicates the directory structure upto given dentry | ||
1774 | + * in the bindex branch. Can create directory structure recursively to the right | ||
1775 | + * also. | ||
1776 | + */ | ||
1777 | +struct dentry *create_parents(struct inode *dir, struct dentry *dentry, | ||
1778 | + int bindex) | ||
1779 | +{ | ||
1780 | + return create_parents_named(dir, dentry, dentry->d_name.name, bindex); | ||
1781 | +} | ||
1782 | + | ||
1783 | +static void __cleanup_dentry(struct dentry * dentry, int bindex, | ||
1784 | + int old_bstart, int old_bend) | ||
1785 | +{ | ||
1786 | + int loop_start; | ||
1787 | + int loop_end; | ||
1788 | + int new_bstart = -1; | ||
1789 | + int new_bend = -1; | ||
1790 | + int i; | ||
1791 | + | ||
1792 | + loop_start = min(old_bstart, bindex); | ||
1793 | + loop_end = max(old_bend, bindex); | ||
1794 | + | ||
1795 | + /* This loop sets the bstart and bend for the new dentry by | ||
1796 | + * traversing from left to right. It also dputs all negative | ||
1797 | + * dentries except bindex | ||
1798 | + */ | ||
1799 | + for (i = loop_start; i <= loop_end; i++) { | ||
1800 | + if (!unionfs_lower_dentry_idx(dentry, i)) | ||
1801 | + continue; | ||
1802 | + | ||
1803 | + if (i == bindex) { | ||
1804 | + new_bend = i; | ||
1805 | + if (new_bstart < 0) | ||
1806 | + new_bstart = i; | ||
1807 | + continue; | ||
1808 | + } | ||
1809 | + | ||
1810 | + if (!unionfs_lower_dentry_idx(dentry, i)->d_inode) { | ||
1811 | + dput(unionfs_lower_dentry_idx(dentry, i)); | ||
1812 | + unionfs_set_lower_dentry_idx(dentry, i, NULL); | ||
1813 | + | ||
1814 | + unionfs_mntput(dentry, i); | ||
1815 | + unionfs_set_lower_mnt_idx(dentry, i, NULL); | ||
1816 | + } else { | ||
1817 | + if (new_bstart < 0) | ||
1818 | + new_bstart = i; | ||
1819 | + new_bend = i; | ||
1820 | + } | ||
1821 | + } | ||
1822 | + | ||
1823 | + if (new_bstart < 0) | ||
1824 | + new_bstart = bindex; | ||
1825 | + if (new_bend < 0) | ||
1826 | + new_bend = bindex; | ||
1827 | + set_dbstart(dentry, new_bstart); | ||
1828 | + set_dbend(dentry, new_bend); | ||
1829 | + | ||
1830 | +} | ||
1831 | + | ||
1832 | +/* set lower inode ptr and update bstart & bend if necessary */ | ||
1833 | +static void __set_inode(struct dentry * upper, struct dentry * lower, | ||
1834 | + int bindex) | ||
1835 | +{ | ||
1836 | + unionfs_set_lower_inode_idx(upper->d_inode, bindex, | ||
1837 | + igrab(lower->d_inode)); | ||
1838 | + if (likely(ibstart(upper->d_inode) > bindex)) | ||
1839 | + ibstart(upper->d_inode) = bindex; | ||
1840 | + if (likely(ibend(upper->d_inode) < bindex)) | ||
1841 | + ibend(upper->d_inode) = bindex; | ||
1842 | + | ||
1843 | +} | ||
1844 | + | ||
1845 | +/* set lower dentry ptr and update bstart & bend if necessary */ | ||
1846 | +static void __set_dentry(struct dentry * upper, struct dentry * lower, | ||
1847 | + int bindex) | ||
1848 | +{ | ||
1849 | + unionfs_set_lower_dentry_idx(upper, bindex, lower); | ||
1850 | + if (likely(dbstart(upper) > bindex)) | ||
1851 | + set_dbstart(upper, bindex); | ||
1852 | + if (likely(dbend(upper) < bindex)) | ||
1853 | + set_dbend(upper, bindex); | ||
1854 | +} | ||
1855 | + | ||
1856 | +/* This function replicates the directory structure upto given dentry | ||
1857 | + * in the bindex branch. | ||
1858 | + */ | ||
1859 | +static struct dentry *create_parents_named(struct inode *dir, | ||
1860 | + struct dentry *dentry, | ||
1861 | + const char *name, int bindex) | ||
1862 | +{ | ||
1863 | + int err; | ||
1864 | + struct dentry *child_dentry; | ||
1865 | + struct dentry *parent_dentry; | ||
1866 | + struct dentry *hidden_parent_dentry = NULL; | ||
1867 | + struct dentry *hidden_dentry = NULL; | ||
1868 | + const char *childname; | ||
1869 | + unsigned int childnamelen; | ||
1870 | + | ||
1871 | + int old_kmalloc_size; | ||
1872 | + int kmalloc_size; | ||
1873 | + int num_dentry; | ||
1874 | + int count; | ||
1875 | + | ||
1876 | + int old_bstart; | ||
1877 | + int old_bend; | ||
1878 | + struct dentry **path = NULL; | ||
1879 | + struct dentry **tmp_path; | ||
1880 | + struct super_block *sb; | ||
1881 | + | ||
1882 | + verify_locked(dentry); | ||
1883 | + | ||
1884 | + /* There is no sense allocating any less than the minimum. */ | ||
1885 | + kmalloc_size = malloc_sizes[0].cs_size; | ||
1886 | + num_dentry = kmalloc_size / sizeof(struct dentry *); | ||
1887 | + | ||
1888 | + if ((err = is_robranch_super(dir->i_sb, bindex))) { | ||
1889 | + hidden_dentry = ERR_PTR(err); | ||
1890 | + goto out; | ||
1891 | + } | ||
1892 | + | ||
1893 | + old_bstart = dbstart(dentry); | ||
1894 | + old_bend = dbend(dentry); | ||
1895 | + | ||
1896 | + hidden_dentry = ERR_PTR(-ENOMEM); | ||
1897 | + path = kzalloc(kmalloc_size, GFP_KERNEL); | ||
1898 | + if (!path) | ||
1899 | + goto out; | ||
1900 | + | ||
1901 | + /* assume the negative dentry of unionfs as the parent dentry */ | ||
1902 | + parent_dentry = dentry; | ||
1903 | + | ||
1904 | + count = 0; | ||
1905 | + /* This loop finds the first parent that exists in the given branch. | ||
1906 | + * We start building the directory structure from there. At the end | ||
1907 | + * of the loop, the following should hold: | ||
1908 | + * - child_dentry is the first nonexistent child | ||
1909 | + * - parent_dentry is the first existent parent | ||
1910 | + * - path[0] is the = deepest child | ||
1911 | + * - path[count] is the first child to create | ||
1912 | + */ | ||
1913 | + do { | ||
1914 | + child_dentry = parent_dentry; | ||
1915 | + | ||
1916 | + /* find the parent directory dentry in unionfs */ | ||
1917 | + parent_dentry = child_dentry->d_parent; | ||
1918 | + unionfs_lock_dentry(parent_dentry); | ||
1919 | + | ||
1920 | + /* find out the hidden_parent_dentry in the given branch */ | ||
1921 | + hidden_parent_dentry = unionfs_lower_dentry_idx(parent_dentry, bindex); | ||
1922 | + | ||
1923 | + /* store the child dentry */ | ||
1924 | + path[count++] = child_dentry; | ||
1925 | + | ||
1926 | + /* grow path table */ | ||
1927 | + if (count == num_dentry) { | ||
1928 | + old_kmalloc_size = kmalloc_size; | ||
1929 | + kmalloc_size *= 2; | ||
1930 | + num_dentry = kmalloc_size / sizeof(struct dentry *); | ||
1931 | + | ||
1932 | + tmp_path = kzalloc(kmalloc_size, GFP_KERNEL); | ||
1933 | + if (!tmp_path) { | ||
1934 | + hidden_dentry = ERR_PTR(-ENOMEM); | ||
1935 | + goto out; | ||
1936 | + } | ||
1937 | + memcpy(tmp_path, path, old_kmalloc_size); | ||
1938 | + kfree(path); | ||
1939 | + path = tmp_path; | ||
1940 | + tmp_path = NULL; | ||
1941 | + } | ||
1942 | + | ||
1943 | + } while (!hidden_parent_dentry); | ||
1944 | + count--; | ||
1945 | + | ||
1946 | + sb = dentry->d_sb; | ||
1947 | + | ||
1948 | + /* This is basically while(child_dentry != dentry). This loop is | ||
1949 | + * horrible to follow and should be replaced with cleaner code. | ||
1950 | + */ | ||
1951 | + while (1) { | ||
1952 | + /* get hidden parent dir in the current branch */ | ||
1953 | + hidden_parent_dentry = unionfs_lower_dentry_idx(parent_dentry, bindex); | ||
1954 | + unionfs_unlock_dentry(parent_dentry); | ||
1955 | + | ||
1956 | + /* init the values to lookup */ | ||
1957 | + childname = child_dentry->d_name.name; | ||
1958 | + childnamelen = child_dentry->d_name.len; | ||
1959 | + | ||
1960 | + if (child_dentry != dentry) { | ||
1961 | + /* lookup child in the underlying file system */ | ||
1962 | + hidden_dentry = | ||
1963 | + lookup_one_len(childname, hidden_parent_dentry, | ||
1964 | + childnamelen); | ||
1965 | + if (IS_ERR(hidden_dentry)) | ||
1966 | + goto out; | ||
1967 | + } else { | ||
1968 | + | ||
1969 | + /* is the name a whiteout of the childname ? | ||
1970 | + * lookup the whiteout child in the underlying file system | ||
1971 | + */ | ||
1972 | + hidden_dentry = | ||
1973 | + lookup_one_len(name, hidden_parent_dentry, | ||
1974 | + strlen(name)); | ||
1975 | + if (IS_ERR(hidden_dentry)) | ||
1976 | + goto out; | ||
1977 | + | ||
1978 | + /* Replace the current dentry (if any) with the new one. */ | ||
1979 | + dput(unionfs_lower_dentry_idx(dentry, bindex)); | ||
1980 | + unionfs_set_lower_dentry_idx(dentry, bindex, hidden_dentry); | ||
1981 | + | ||
1982 | + __cleanup_dentry(dentry, bindex, old_bstart, old_bend); | ||
1983 | + break; | ||
1984 | + } | ||
1985 | + | ||
1986 | + if (hidden_dentry->d_inode) { | ||
1987 | + /* since this already exists we dput to avoid | ||
1988 | + * multiple references on the same dentry | ||
1989 | + */ | ||
1990 | + dput(hidden_dentry); | ||
1991 | + } else { | ||
1992 | + struct sioq_args args; | ||
1993 | + | ||
1994 | + /* its a negative dentry, create a new dir */ | ||
1995 | + hidden_parent_dentry = lock_parent(hidden_dentry); | ||
1996 | + | ||
1997 | + args.mkdir.parent = hidden_parent_dentry->d_inode; | ||
1998 | + args.mkdir.dentry = hidden_dentry; | ||
1999 | + args.mkdir.mode = child_dentry->d_inode->i_mode; | ||
2000 | + | ||
2001 | + run_sioq(__unionfs_mkdir, &args); | ||
2002 | + err = args.err; | ||
2003 | + | ||
2004 | + if (!err) | ||
2005 | + err = copyup_permissions(dir->i_sb, | ||
2006 | + child_dentry, hidden_dentry); | ||
2007 | + unlock_dir(hidden_parent_dentry); | ||
2008 | + if (err) { | ||
2009 | + dput(hidden_dentry); | ||
2010 | + hidden_dentry = ERR_PTR(err); | ||
2011 | + goto out; | ||
2012 | + } | ||
2013 | + | ||
2014 | + } | ||
2015 | + | ||
2016 | + __set_inode(child_dentry, hidden_dentry, bindex); | ||
2017 | + __set_dentry(child_dentry, hidden_dentry, bindex); | ||
2018 | + | ||
2019 | + parent_dentry = child_dentry; | ||
2020 | + child_dentry = path[--count]; | ||
2021 | + } | ||
2022 | +out: | ||
2023 | + kfree(path); | ||
2024 | + return hidden_dentry; | ||
2025 | +} | ||
2026 | + | ||
2027 | diff --git a/fs/unionfs/dentry.c b/fs/unionfs/dentry.c | ||
2028 | new file mode 100644 | ||
2029 | index 0000000..9eb143d | ||
2030 | --- /dev/null | ||
2031 | +++ b/fs/unionfs/dentry.c | ||
2032 | @@ -0,0 +1,333 @@ | ||
2033 | +/* | ||
2034 | + * Copyright (c) 2003-2007 Erez Zadok | ||
2035 | + * Copyright (c) 2003-2006 Charles P. Wright | ||
2036 | + * Copyright (c) 2005-2007 Josef 'Jeff' Sipek | ||
2037 | + * Copyright (c) 2005-2006 Junjiro Okajima | ||
2038 | + * Copyright (c) 2005 Arun M. Krishnakumar | ||
2039 | + * Copyright (c) 2004-2006 David P. Quigley | ||
2040 | + * Copyright (c) 2003-2004 Mohammad Nayyer Zubair | ||
2041 | + * Copyright (c) 2003 Puja Gupta | ||
2042 | + * Copyright (c) 2003 Harikesavan Krishnan | ||
2043 | + * Copyright (c) 2003-2007 Stony Brook University | ||
2044 | + * Copyright (c) 2003-2007 The Research Foundation of State University of New York | ||
2045 | + * | ||
2046 | + * This program is free software; you can redistribute it and/or modify | ||
2047 | + * it under the terms of the GNU General Public License version 2 as | ||
2048 | + * published by the Free Software Foundation. | ||
2049 | + */ | ||
2050 | + | ||
2051 | +#include "union.h" | ||
2052 | + | ||
2053 | + | ||
2054 | +/* | ||
2055 | + * Revalidate a single dentry. | ||
2056 | + * Assume that dentry's info node is locked. | ||
2057 | + * Assume that parent(s) are all valid already, but | ||
2058 | + * the child may not yet be valid. | ||
2059 | + * Returns 1 if valid, 0 otherwise. | ||
2060 | + */ | ||
2061 | +static int __unionfs_d_revalidate_one(struct dentry *dentry, struct nameidata *nd) | ||
2062 | +{ | ||
2063 | + int valid = 1; /* default is valid (1); invalid is 0. */ | ||
2064 | + struct dentry *hidden_dentry; | ||
2065 | + int bindex, bstart, bend; | ||
2066 | + int sbgen, dgen; | ||
2067 | + int positive = 0; | ||
2068 | + int locked = 0; | ||
2069 | + int interpose_flag; | ||
2070 | + | ||
2071 | + struct nameidata lowernd; /* TODO: be gentler to the stack */ | ||
2072 | + | ||
2073 | + if (nd) | ||
2074 | + memcpy(&lowernd, nd, sizeof(struct nameidata)); | ||
2075 | + else | ||
2076 | + memset(&lowernd, 0, sizeof(struct nameidata)); | ||
2077 | + | ||
2078 | + verify_locked(dentry); | ||
2079 | + | ||
2080 | + /* if the dentry is unhashed, do NOT revalidate */ | ||
2081 | + if (d_deleted(dentry)) { | ||
2082 | + printk(KERN_DEBUG "unhashed dentry being revalidated: %*s\n", | ||
2083 | + dentry->d_name.len, dentry->d_name.name); | ||
2084 | + goto out; | ||
2085 | + } | ||
2086 | + | ||
2087 | + BUG_ON(dbstart(dentry) == -1); | ||
2088 | + if (dentry->d_inode) | ||
2089 | + positive = 1; | ||
2090 | + dgen = atomic_read(&UNIONFS_D(dentry)->generation); | ||
2091 | + sbgen = atomic_read(&UNIONFS_SB(dentry->d_sb)->generation); | ||
2092 | + /* If we are working on an unconnected dentry, then there is no | ||
2093 | + * revalidation to be done, because this file does not exist within the | ||
2094 | + * namespace, and Unionfs operates on the namespace, not data. | ||
2095 | + */ | ||
2096 | + if (sbgen != dgen) { | ||
2097 | + struct dentry *result; | ||
2098 | + int pdgen; | ||
2099 | + | ||
2100 | + /* The root entry should always be valid */ | ||
2101 | + BUG_ON(IS_ROOT(dentry)); | ||
2102 | + | ||
2103 | + /* We can't work correctly if our parent isn't valid. */ | ||
2104 | + pdgen = atomic_read(&UNIONFS_D(dentry->d_parent)->generation); | ||
2105 | + BUG_ON(pdgen != sbgen); /* should never happen here */ | ||
2106 | + | ||
2107 | + /* Free the pointers for our inodes and this dentry. */ | ||
2108 | + bstart = dbstart(dentry); | ||
2109 | + bend = dbend(dentry); | ||
2110 | + if (bstart >= 0) { | ||
2111 | + struct dentry *hidden_dentry; | ||
2112 | + for (bindex = bstart; bindex <= bend; bindex++) { | ||
2113 | + hidden_dentry = | ||
2114 | + unionfs_lower_dentry_idx(dentry, bindex); | ||
2115 | + dput(hidden_dentry); | ||
2116 | + } | ||
2117 | + } | ||
2118 | + set_dbstart(dentry, -1); | ||
2119 | + set_dbend(dentry, -1); | ||
2120 | + | ||
2121 | + interpose_flag = INTERPOSE_REVAL_NEG; | ||
2122 | + if (positive) { | ||
2123 | + interpose_flag = INTERPOSE_REVAL; | ||
2124 | + /* | ||
2125 | + * During BRM, the VFS could already hold a lock on | ||
2126 | + * a file being read, so don't lock it again | ||
2127 | + * (deadlock), but if you lock it in this function, | ||
2128 | + * then release it here too. | ||
2129 | + */ | ||
2130 | + if (!mutex_is_locked(&dentry->d_inode->i_mutex)) { | ||
2131 | + mutex_lock(&dentry->d_inode->i_mutex); | ||
2132 | + locked = 1; | ||
2133 | + } | ||
2134 | + | ||
2135 | + bstart = ibstart(dentry->d_inode); | ||
2136 | + bend = ibend(dentry->d_inode); | ||
2137 | + if (bstart >= 0) { | ||
2138 | + struct inode *hidden_inode; | ||
2139 | + for (bindex = bstart; bindex <= bend; bindex++) { | ||
2140 | + hidden_inode = | ||
2141 | + unionfs_lower_inode_idx(dentry->d_inode, | ||
2142 | + bindex); | ||
2143 | + iput(hidden_inode); | ||
2144 | + } | ||
2145 | + } | ||
2146 | + kfree(UNIONFS_I(dentry->d_inode)->lower_inodes); | ||
2147 | + UNIONFS_I(dentry->d_inode)->lower_inodes = NULL; | ||
2148 | + ibstart(dentry->d_inode) = -1; | ||
2149 | + ibend(dentry->d_inode) = -1; | ||
2150 | + if (locked) | ||
2151 | + mutex_unlock(&dentry->d_inode->i_mutex); | ||
2152 | + } | ||
2153 | + | ||
2154 | + result = unionfs_lookup_backend(dentry, &lowernd, interpose_flag); | ||
2155 | + if (result) { | ||
2156 | + if (IS_ERR(result)) { | ||
2157 | + valid = 0; | ||
2158 | + goto out; | ||
2159 | + } | ||
2160 | + /* current unionfs_lookup_backend() doesn't return | ||
2161 | + * a valid dentry | ||
2162 | + */ | ||
2163 | + dput(dentry); | ||
2164 | + dentry = result; | ||
2165 | + } | ||
2166 | + | ||
2167 | + if (positive && UNIONFS_I(dentry->d_inode)->stale) { | ||
2168 | + make_bad_inode(dentry->d_inode); | ||
2169 | + d_drop(dentry); | ||
2170 | + valid = 0; | ||
2171 | + goto out; | ||
2172 | + } | ||
2173 | + goto out; | ||
2174 | + } | ||
2175 | + | ||
2176 | + /* The revalidation must occur across all branches */ | ||
2177 | + bstart = dbstart(dentry); | ||
2178 | + bend = dbend(dentry); | ||
2179 | + BUG_ON(bstart == -1); | ||
2180 | + for (bindex = bstart; bindex <= bend; bindex++) { | ||
2181 | + hidden_dentry = unionfs_lower_dentry_idx(dentry, bindex); | ||
2182 | + if (!hidden_dentry || !hidden_dentry->d_op | ||
2183 | + || !hidden_dentry->d_op->d_revalidate) | ||
2184 | + continue; | ||
2185 | + if (!hidden_dentry->d_op->d_revalidate(hidden_dentry, &lowernd)) | ||
2186 | + valid = 0; | ||
2187 | + } | ||
2188 | + | ||
2189 | + if (!dentry->d_inode) | ||
2190 | + valid = 0; | ||
2191 | + | ||
2192 | + if (valid) { | ||
2193 | + fsstack_copy_attr_all(dentry->d_inode, | ||
2194 | + unionfs_lower_inode(dentry->d_inode), | ||
2195 | + unionfs_get_nlinks); | ||
2196 | + fsstack_copy_inode_size(dentry->d_inode, | ||
2197 | + unionfs_lower_inode(dentry->d_inode)); | ||
2198 | + } | ||
2199 | + | ||
2200 | +out: | ||
2201 | + return valid; | ||
2202 | +} | ||
2203 | + | ||
2204 | +/* | ||
2205 | + * Revalidate a parent chain of dentries, then the actual node. | ||
2206 | + * Assumes that dentry is locked, but will lock all parents if/when needed. | ||
2207 | + */ | ||
2208 | +int __unionfs_d_revalidate_chain(struct dentry *dentry, struct nameidata *nd) | ||
2209 | +{ | ||
2210 | + int valid = 0; /* default is invalid (0); valid is 1. */ | ||
2211 | + struct dentry **chain = NULL; /* chain of dentries to reval */ | ||
2212 | + int chain_len = 0; | ||
2213 | + struct dentry *dtmp; | ||
2214 | + int sbgen, dgen, i; | ||
2215 | + int saved_bstart, saved_bend, bindex; | ||
2216 | + | ||
2217 | + /* find length of chain needed to revalidate */ | ||
2218 | + /* XXX: should I grab some global (dcache?) lock? */ | ||
2219 | + chain_len = 0; | ||
2220 | + sbgen = atomic_read(&UNIONFS_SB(dentry->d_sb)->generation); | ||
2221 | + dtmp = dentry->d_parent; | ||
2222 | + dgen = atomic_read(&UNIONFS_D(dtmp)->generation); | ||
2223 | + while (sbgen != dgen) { | ||
2224 | + /* The root entry should always be valid */ | ||
2225 | + BUG_ON(IS_ROOT(dtmp)); | ||
2226 | + chain_len++; | ||
2227 | + dtmp = dtmp->d_parent; | ||
2228 | + dgen = atomic_read(&UNIONFS_D(dtmp)->generation); | ||
2229 | + } | ||
2230 | + if (chain_len == 0) { | ||
2231 | + goto out_this; /* shortcut if parents are OK */ | ||
2232 | + } | ||
2233 | + | ||
2234 | + /* | ||
2235 | + * Allocate array of dentries to reval. We could use linked lists, | ||
2236 | + * but the number of entries we need to alloc here is often small, | ||
2237 | + * and short lived, so locality will be better. | ||
2238 | + */ | ||
2239 | + chain = kzalloc(chain_len * sizeof(struct dentry *), GFP_KERNEL); | ||
2240 | + if (!chain) { | ||
2241 | + printk("unionfs: no more memory in %s\n", __FUNCTION__); | ||
2242 | + goto out; | ||
2243 | + } | ||
2244 | + | ||
2245 | + /* | ||
2246 | + * lock all dentries in chain, in child to parent order. | ||
2247 | + * if failed, then sleep for a little, then retry. | ||
2248 | + */ | ||
2249 | + dtmp = dentry->d_parent; | ||
2250 | + for (i=chain_len-1; i>=0; i--) { | ||
2251 | + chain[i] = dget(dtmp); | ||
2252 | + dtmp = dtmp->d_parent; | ||
2253 | + } | ||
2254 | + | ||
2255 | + /* | ||
2256 | + * call __unionfs_d_revalidate() on each dentry, but in parent to | ||
2257 | + * child order. | ||
2258 | + */ | ||
2259 | + for (i=0; i<chain_len; i++) { | ||
2260 | + unionfs_lock_dentry(chain[i]); | ||
2261 | + saved_bstart = dbstart(chain[i]); | ||
2262 | + saved_bend = dbend(chain[i]); | ||
2263 | + sbgen = atomic_read(&UNIONFS_SB(dentry->d_sb)->generation); | ||
2264 | + dgen = atomic_read(&UNIONFS_D(chain[i])->generation); | ||
2265 | + | ||
2266 | + valid = __unionfs_d_revalidate_one(chain[i], nd); | ||
2267 | + /* XXX: is this the correct mntput condition?! */ | ||
2268 | + if (valid && chain_len > 0 && | ||
2269 | + sbgen != dgen && chain[i]->d_inode && | ||
2270 | + S_ISDIR(chain[i]->d_inode->i_mode)) { | ||
2271 | + for (bindex = saved_bstart; bindex <= saved_bend; bindex++) | ||
2272 | + unionfs_mntput(chain[i], bindex); | ||
2273 | + } | ||
2274 | + unionfs_unlock_dentry(chain[i]); | ||
2275 | + | ||
2276 | + if (!valid) { | ||
2277 | + goto out_free; | ||
2278 | + } | ||
2279 | + } | ||
2280 | + | ||
2281 | + | ||
2282 | + out_this: | ||
2283 | + /* finally, lock this dentry and revalidate it */ | ||
2284 | + verify_locked(dentry); | ||
2285 | + dgen = atomic_read(&UNIONFS_D(dentry)->generation); | ||
2286 | + saved_bstart = dbstart(dentry); | ||
2287 | + saved_bend = dbend(dentry); | ||
2288 | + valid = __unionfs_d_revalidate_one(dentry, nd); | ||
2289 | + | ||
2290 | + if (valid && chain_len > 0 && sbgen != dgen) { | ||
2291 | + for (bindex = saved_bstart; bindex <= saved_bend; bindex++) | ||
2292 | + unionfs_mntput(dentry, bindex); | ||
2293 | + } | ||
2294 | + | ||
2295 | + out_free: | ||
2296 | + /* unlock/dput all dentries in chain and return status */ | ||
2297 | + if (chain_len > 0) { | ||
2298 | + for (i=0; i<chain_len; i++) { | ||
2299 | + dput(chain[i]); | ||
2300 | + } | ||
2301 | + kfree(chain); | ||
2302 | + } | ||
2303 | + out: | ||
2304 | + return valid; | ||
2305 | +} | ||
2306 | + | ||
2307 | +static int unionfs_d_revalidate(struct dentry *dentry, struct nameidata *nd) | ||
2308 | +{ | ||
2309 | + int err; | ||
2310 | + | ||
2311 | + unionfs_lock_dentry(dentry); | ||
2312 | + err = __unionfs_d_revalidate_chain(dentry, nd); | ||
2313 | + unionfs_unlock_dentry(dentry); | ||
2314 | + | ||
2315 | + return err; | ||
2316 | +} | ||
2317 | + | ||
2318 | +/* | ||
2319 | + * At this point no one can reference this dentry, so we don't have to be | ||
2320 | + * careful about concurrent access. | ||
2321 | + */ | ||
2322 | +static void unionfs_d_release(struct dentry *dentry) | ||
2323 | +{ | ||
2324 | + int bindex, bstart, bend; | ||
2325 | + | ||
2326 | + /* this could be a negative dentry, so check first */ | ||
2327 | + if (!UNIONFS_D(dentry)) { | ||
2328 | + printk(KERN_DEBUG "dentry without private data: %.*s", | ||
2329 | + dentry->d_name.len, dentry->d_name.name); | ||
2330 | + goto out; | ||
2331 | + } else if (dbstart(dentry) < 0) { | ||
2332 | + /* this is due to a failed lookup */ | ||
2333 | + printk(KERN_DEBUG "dentry without hidden dentries : %.*s", | ||
2334 | + dentry->d_name.len, dentry->d_name.name); | ||
2335 | + goto out_free; | ||
2336 | + } | ||
2337 | + | ||
2338 | + /* Release all the hidden dentries */ | ||
2339 | + bstart = dbstart(dentry); | ||
2340 | + bend = dbend(dentry); | ||
2341 | + for (bindex = bstart; bindex <= bend; bindex++) { | ||
2342 | + dput(unionfs_lower_dentry_idx(dentry, bindex)); | ||
2343 | + unionfs_mntput(dentry, bindex); | ||
2344 | + | ||
2345 | + unionfs_set_lower_dentry_idx(dentry, bindex, NULL); | ||
2346 | + unionfs_set_lower_mnt_idx(dentry, bindex, NULL); | ||
2347 | + } | ||
2348 | + /* free private data (unionfs_dentry_info) here */ | ||
2349 | + kfree(UNIONFS_D(dentry)->lower_paths); | ||
2350 | + UNIONFS_D(dentry)->lower_paths = NULL; | ||
2351 | + | ||
2352 | +out_free: | ||
2353 | + /* No need to unlock it, because it is disappeared. */ | ||
2354 | + free_dentry_private_data(UNIONFS_D(dentry)); | ||
2355 | + dentry->d_fsdata = NULL; /* just to be safe */ | ||
2356 | + | ||
2357 | +out: | ||
2358 | + return; | ||
2359 | +} | ||
2360 | + | ||
2361 | +struct dentry_operations unionfs_dops = { | ||
2362 | + .d_revalidate = unionfs_d_revalidate, | ||
2363 | + .d_release = unionfs_d_release, | ||
2364 | +}; | ||
2365 | + | ||
2366 | diff --git a/fs/unionfs/dirfops.c b/fs/unionfs/dirfops.c | ||
2367 | new file mode 100644 | ||
2368 | index 0000000..6ff32a0 | ||
2369 | --- /dev/null | ||
2370 | +++ b/fs/unionfs/dirfops.c | ||
2371 | @@ -0,0 +1,267 @@ | ||
2372 | +/* | ||
2373 | + * Copyright (c) 2003-2007 Erez Zadok | ||
2374 | + * Copyright (c) 2003-2006 Charles P. Wright | ||
2375 | + * Copyright (c) 2005-2007 Josef 'Jeff' Sipek | ||
2376 | + * Copyright (c) 2005-2006 Junjiro Okajima | ||
2377 | + * Copyright (c) 2005 Arun M. Krishnakumar | ||
2378 | + * Copyright (c) 2004-2006 David P. Quigley | ||
2379 | + * Copyright (c) 2003-2004 Mohammad Nayyer Zubair | ||
2380 | + * Copyright (c) 2003 Puja Gupta | ||
2381 | + * Copyright (c) 2003 Harikesavan Krishnan | ||
2382 | + * Copyright (c) 2003-2007 Stony Brook University | ||
2383 | + * Copyright (c) 2003-2007 The Research Foundation of State University of New York | ||
2384 | + * | ||
2385 | + * This program is free software; you can redistribute it and/or modify | ||
2386 | + * it under the terms of the GNU General Public License version 2 as | ||
2387 | + * published by the Free Software Foundation. | ||
2388 | + */ | ||
2389 | + | ||
2390 | +#include "union.h" | ||
2391 | + | ||
2392 | +/* Make sure our rdstate is playing by the rules. */ | ||
2393 | +static void verify_rdstate_offset(struct unionfs_dir_state *rdstate) | ||
2394 | +{ | ||
2395 | + BUG_ON(rdstate->offset >= DIREOF); | ||
2396 | + BUG_ON(rdstate->cookie >= MAXRDCOOKIE); | ||
2397 | +} | ||
2398 | + | ||
2399 | +struct unionfs_getdents_callback { | ||
2400 | + struct unionfs_dir_state *rdstate; | ||
2401 | + void *dirent; | ||
2402 | + int entries_written; | ||
2403 | + int filldir_called; | ||
2404 | + int filldir_error; | ||
2405 | + filldir_t filldir; | ||
2406 | + struct super_block *sb; | ||
2407 | +}; | ||
2408 | + | ||
2409 | +/* based on generic filldir in fs/readir.c */ | ||
2410 | +static int unionfs_filldir(void *dirent, const char *name, int namelen, | ||
2411 | + loff_t offset, u64 ino, unsigned int d_type) | ||
2412 | +{ | ||
2413 | + struct unionfs_getdents_callback *buf = dirent; | ||
2414 | + struct filldir_node *found = NULL; | ||
2415 | + int err = 0; | ||
2416 | + int is_wh_entry = 0; | ||
2417 | + | ||
2418 | + buf->filldir_called++; | ||
2419 | + | ||
2420 | + if ((namelen > UNIONFS_WHLEN) && | ||
2421 | + !strncmp(name, UNIONFS_WHPFX, UNIONFS_WHLEN)) { | ||
2422 | + name += UNIONFS_WHLEN; | ||
2423 | + namelen -= UNIONFS_WHLEN; | ||
2424 | + is_wh_entry = 1; | ||
2425 | + } | ||
2426 | + | ||
2427 | + found = find_filldir_node(buf->rdstate, name, namelen); | ||
2428 | + | ||
2429 | + if (found) | ||
2430 | + goto out; | ||
2431 | + | ||
2432 | + /* if 'name' isn't a whiteout, filldir it. */ | ||
2433 | + if (!is_wh_entry) { | ||
2434 | + off_t pos = rdstate2offset(buf->rdstate); | ||
2435 | + u64 unionfs_ino = ino; | ||
2436 | + | ||
2437 | + if (!err) { | ||
2438 | + err = buf->filldir(buf->dirent, name, namelen, pos, | ||
2439 | + unionfs_ino, d_type); | ||
2440 | + buf->rdstate->offset++; | ||
2441 | + verify_rdstate_offset(buf->rdstate); | ||
2442 | + } | ||
2443 | + } | ||
2444 | + /* If we did fill it, stuff it in our hash, otherwise return an error */ | ||
2445 | + if (err) { | ||
2446 | + buf->filldir_error = err; | ||
2447 | + goto out; | ||
2448 | + } | ||
2449 | + buf->entries_written++; | ||
2450 | + if ((err = add_filldir_node(buf->rdstate, name, namelen, | ||
2451 | + buf->rdstate->bindex, is_wh_entry))) | ||
2452 | + buf->filldir_error = err; | ||
2453 | + | ||
2454 | +out: | ||
2455 | + return err; | ||
2456 | +} | ||
2457 | + | ||
2458 | +static int unionfs_readdir(struct file *file, void *dirent, filldir_t filldir) | ||
2459 | +{ | ||
2460 | + int err = 0; | ||
2461 | + struct file *hidden_file = NULL; | ||
2462 | + struct inode *inode = NULL; | ||
2463 | + struct unionfs_getdents_callback buf; | ||
2464 | + struct unionfs_dir_state *uds; | ||
2465 | + int bend; | ||
2466 | + loff_t offset; | ||
2467 | + | ||
2468 | + unionfs_read_lock(file->f_dentry->d_sb); | ||
2469 | + if ((err = unionfs_file_revalidate(file, 0))) | ||
2470 | + goto out; | ||
2471 | + | ||
2472 | + inode = file->f_dentry->d_inode; | ||
2473 | + | ||
2474 | + uds = UNIONFS_F(file)->rdstate; | ||
2475 | + if (!uds) { | ||
2476 | + if (file->f_pos == DIREOF) { | ||
2477 | + goto out; | ||
2478 | + } else if (file->f_pos > 0) { | ||
2479 | + uds = find_rdstate(inode, file->f_pos); | ||
2480 | + if (!uds) { | ||
2481 | + err = -ESTALE; | ||
2482 | + goto out; | ||
2483 | + } | ||
2484 | + UNIONFS_F(file)->rdstate = uds; | ||
2485 | + } else { | ||
2486 | + init_rdstate(file); | ||
2487 | + uds = UNIONFS_F(file)->rdstate; | ||
2488 | + } | ||
2489 | + } | ||
2490 | + bend = fbend(file); | ||
2491 | + | ||
2492 | + while (uds->bindex <= bend) { | ||
2493 | + hidden_file = unionfs_lower_file_idx(file, uds->bindex); | ||
2494 | + if (!hidden_file) { | ||
2495 | + uds->bindex++; | ||
2496 | + uds->dirpos = 0; | ||
2497 | + continue; | ||
2498 | + } | ||
2499 | + | ||
2500 | + /* prepare callback buffer */ | ||
2501 | + buf.filldir_called = 0; | ||
2502 | + buf.filldir_error = 0; | ||
2503 | + buf.entries_written = 0; | ||
2504 | + buf.dirent = dirent; | ||
2505 | + buf.filldir = filldir; | ||
2506 | + buf.rdstate = uds; | ||
2507 | + buf.sb = inode->i_sb; | ||
2508 | + | ||
2509 | + /* Read starting from where we last left off. */ | ||
2510 | + offset = vfs_llseek(hidden_file, uds->dirpos, SEEK_SET); | ||
2511 | + if (offset < 0) { | ||
2512 | + err = offset; | ||
2513 | + goto out; | ||
2514 | + } | ||
2515 | + err = vfs_readdir(hidden_file, unionfs_filldir, &buf); | ||
2516 | + | ||
2517 | + /* Save the position for when we continue. */ | ||
2518 | + offset = vfs_llseek(hidden_file, 0, SEEK_CUR); | ||
2519 | + if (offset < 0) { | ||
2520 | + err = offset; | ||
2521 | + goto out; | ||
2522 | + } | ||
2523 | + uds->dirpos = offset; | ||
2524 | + | ||
2525 | + /* Copy the atime. */ | ||
2526 | + fsstack_copy_attr_atime(inode, hidden_file->f_dentry->d_inode); | ||
2527 | + | ||
2528 | + if (err < 0) | ||
2529 | + goto out; | ||
2530 | + | ||
2531 | + if (buf.filldir_error) | ||
2532 | + break; | ||
2533 | + | ||
2534 | + if (!buf.entries_written) { | ||
2535 | + uds->bindex++; | ||
2536 | + uds->dirpos = 0; | ||
2537 | + } | ||
2538 | + } | ||
2539 | + | ||
2540 | + if (!buf.filldir_error && uds->bindex >= bend) { | ||
2541 | + /* Save the number of hash entries for next time. */ | ||
2542 | + UNIONFS_I(inode)->hashsize = uds->hashentries; | ||
2543 | + free_rdstate(uds); | ||
2544 | + UNIONFS_F(file)->rdstate = NULL; | ||
2545 | + file->f_pos = DIREOF; | ||
2546 | + } else | ||
2547 | + file->f_pos = rdstate2offset(uds); | ||
2548 | + | ||
2549 | +out: | ||
2550 | + unionfs_read_unlock(file->f_dentry->d_sb); | ||
2551 | + return err; | ||
2552 | +} | ||
2553 | + | ||
2554 | +/* This is not meant to be a generic repositioning function. If you do | ||
2555 | + * things that aren't supported, then we return EINVAL. | ||
2556 | + * | ||
2557 | + * What is allowed: | ||
2558 | + * (1) seeking to the same position that you are currently at | ||
2559 | + * This really has no effect, but returns where you are. | ||
2560 | + * (2) seeking to the beginning of the file | ||
2561 | + * This throws out all state, and lets you begin again. | ||
2562 | + */ | ||
2563 | +static loff_t unionfs_dir_llseek(struct file *file, loff_t offset, int origin) | ||
2564 | +{ | ||
2565 | + struct unionfs_dir_state *rdstate; | ||
2566 | + loff_t err; | ||
2567 | + | ||
2568 | + unionfs_read_lock(file->f_dentry->d_sb); | ||
2569 | + if ((err = unionfs_file_revalidate(file, 0))) | ||
2570 | + goto out; | ||
2571 | + | ||
2572 | + rdstate = UNIONFS_F(file)->rdstate; | ||
2573 | + | ||
2574 | + /* We let users seek to their current position, but not anywhere else. */ | ||
2575 | + if (!offset) { | ||
2576 | + switch (origin) { | ||
2577 | + case SEEK_SET: | ||
2578 | + if (rdstate) { | ||
2579 | + free_rdstate(rdstate); | ||
2580 | + UNIONFS_F(file)->rdstate = NULL; | ||
2581 | + } | ||
2582 | + init_rdstate(file); | ||
2583 | + err = 0; | ||
2584 | + break; | ||
2585 | + case SEEK_CUR: | ||
2586 | + err = file->f_pos; | ||
2587 | + break; | ||
2588 | + case SEEK_END: | ||
2589 | + /* Unsupported, because we would break everything. */ | ||
2590 | + err = -EINVAL; | ||
2591 | + break; | ||
2592 | + } | ||
2593 | + } else { | ||
2594 | + switch (origin) { | ||
2595 | + case SEEK_SET: | ||
2596 | + if (rdstate) { | ||
2597 | + if (offset == rdstate2offset(rdstate)) | ||
2598 | + err = offset; | ||
2599 | + else if (file->f_pos == DIREOF) | ||
2600 | + err = DIREOF; | ||
2601 | + else | ||
2602 | + err = -EINVAL; | ||
2603 | + } else { | ||
2604 | + rdstate = find_rdstate(file->f_dentry->d_inode, | ||
2605 | + offset); | ||
2606 | + if (rdstate) { | ||
2607 | + UNIONFS_F(file)->rdstate = rdstate; | ||
2608 | + err = rdstate->offset; | ||
2609 | + } else | ||
2610 | + err = -EINVAL; | ||
2611 | + } | ||
2612 | + break; | ||
2613 | + case SEEK_CUR: | ||
2614 | + case SEEK_END: | ||
2615 | + /* Unsupported, because we would break everything. */ | ||
2616 | + err = -EINVAL; | ||
2617 | + break; | ||
2618 | + } | ||
2619 | + } | ||
2620 | + | ||
2621 | +out: | ||
2622 | + unionfs_read_unlock(file->f_dentry->d_sb); | ||
2623 | + return err; | ||
2624 | +} | ||
2625 | + | ||
2626 | +/* Trimmed directory options, we shouldn't pass everything down since | ||
2627 | + * we don't want to operate on partial directories. | ||
2628 | + */ | ||
2629 | +struct file_operations unionfs_dir_fops = { | ||
2630 | + .llseek = unionfs_dir_llseek, | ||
2631 | + .read = generic_read_dir, | ||
2632 | + .readdir = unionfs_readdir, | ||
2633 | + .unlocked_ioctl = unionfs_ioctl, | ||
2634 | + .open = unionfs_open, | ||
2635 | + .release = unionfs_file_release, | ||
2636 | + .flush = unionfs_flush, | ||
2637 | +}; | ||
2638 | + | ||
2639 | diff --git a/fs/unionfs/dirhelper.c b/fs/unionfs/dirhelper.c | ||
2640 | new file mode 100644 | ||
2641 | index 0000000..bd15eb4 | ||
2642 | --- /dev/null | ||
2643 | +++ b/fs/unionfs/dirhelper.c | ||
2644 | @@ -0,0 +1,276 @@ | ||
2645 | +/* | ||
2646 | + * Copyright (c) 2003-2007 Erez Zadok | ||
2647 | + * Copyright (c) 2003-2006 Charles P. Wright | ||
2648 | + * Copyright (c) 2005-2007 Josef 'Jeff' Sipek | ||
2649 | + * Copyright (c) 2005-2006 Junjiro Okajima | ||
2650 | + * Copyright (c) 2005 Arun M. Krishnakumar | ||
2651 | + * Copyright (c) 2004-2006 David P. Quigley | ||
2652 | + * Copyright (c) 2003-2004 Mohammad Nayyer Zubair | ||
2653 | + * Copyright (c) 2003 Puja Gupta | ||
2654 | + * Copyright (c) 2003 Harikesavan Krishnan | ||
2655 | + * Copyright (c) 2003-2007 Stony Brook University | ||
2656 | + * Copyright (c) 2003-2007 The Research Foundation of State University of New York | ||
2657 | + * | ||
2658 | + * This program is free software; you can redistribute it and/or modify | ||
2659 | + * it under the terms of the GNU General Public License version 2 as | ||
2660 | + * published by the Free Software Foundation. | ||
2661 | + */ | ||
2662 | + | ||
2663 | +#include "union.h" | ||
2664 | + | ||
2665 | +/* Delete all of the whiteouts in a given directory for rmdir. | ||
2666 | + * | ||
2667 | + * hidden directory inode should be locked | ||
2668 | + */ | ||
2669 | +int do_delete_whiteouts(struct dentry *dentry, int bindex, | ||
2670 | + struct unionfs_dir_state *namelist) | ||
2671 | +{ | ||
2672 | + int err = 0; | ||
2673 | + struct dentry *hidden_dir_dentry = NULL; | ||
2674 | + struct dentry *hidden_dentry; | ||
2675 | + char *name = NULL, *p; | ||
2676 | + struct inode *hidden_dir; | ||
2677 | + | ||
2678 | + int i; | ||
2679 | + struct list_head *pos; | ||
2680 | + struct filldir_node *cursor; | ||
2681 | + | ||
2682 | + /* Find out hidden parent dentry */ | ||
2683 | + hidden_dir_dentry = unionfs_lower_dentry_idx(dentry, bindex); | ||
2684 | + BUG_ON(!S_ISDIR(hidden_dir_dentry->d_inode->i_mode)); | ||
2685 | + hidden_dir = hidden_dir_dentry->d_inode; | ||
2686 | + BUG_ON(!S_ISDIR(hidden_dir->i_mode)); | ||
2687 | + | ||
2688 | + err = -ENOMEM; | ||
2689 | + name = __getname(); | ||
2690 | + if (!name) | ||
2691 | + goto out; | ||
2692 | + strcpy(name, UNIONFS_WHPFX); | ||
2693 | + p = name + UNIONFS_WHLEN; | ||
2694 | + | ||
2695 | + err = 0; | ||
2696 | + for (i = 0; !err && i < namelist->size; i++) { | ||
2697 | + list_for_each(pos, &namelist->list[i]) { | ||
2698 | + cursor = | ||
2699 | + list_entry(pos, struct filldir_node, file_list); | ||
2700 | + /* Only operate on whiteouts in this branch. */ | ||
2701 | + if (cursor->bindex != bindex) | ||
2702 | + continue; | ||
2703 | + if (!cursor->whiteout) | ||
2704 | + continue; | ||
2705 | + | ||
2706 | + strcpy(p, cursor->name); | ||
2707 | + hidden_dentry = | ||
2708 | + lookup_one_len(name, hidden_dir_dentry, | ||
2709 | + cursor->namelen + UNIONFS_WHLEN); | ||
2710 | + if (IS_ERR(hidden_dentry)) { | ||
2711 | + err = PTR_ERR(hidden_dentry); | ||
2712 | + break; | ||
2713 | + } | ||
2714 | + if (hidden_dentry->d_inode) | ||
2715 | + err = vfs_unlink(hidden_dir, hidden_dentry); | ||
2716 | + dput(hidden_dentry); | ||
2717 | + if (err) | ||
2718 | + break; | ||
2719 | + } | ||
2720 | + } | ||
2721 | + | ||
2722 | + __putname(name); | ||
2723 | + | ||
2724 | + /* After all of the removals, we should copy the attributes once. */ | ||
2725 | + fsstack_copy_attr_times(dentry->d_inode, hidden_dir_dentry->d_inode); | ||
2726 | + | ||
2727 | +out: | ||
2728 | + return err; | ||
2729 | +} | ||
2730 | + | ||
2731 | +/* delete whiteouts in a dir (for rmdir operation) using sioq if necessary */ | ||
2732 | +int delete_whiteouts(struct dentry *dentry, int bindex, | ||
2733 | + struct unionfs_dir_state *namelist) | ||
2734 | +{ | ||
2735 | + int err; | ||
2736 | + struct super_block *sb; | ||
2737 | + struct dentry *hidden_dir_dentry; | ||
2738 | + struct inode *hidden_dir; | ||
2739 | + | ||
2740 | + struct sioq_args args; | ||
2741 | + | ||
2742 | + sb = dentry->d_sb; | ||
2743 | + unionfs_read_lock(sb); | ||
2744 | + | ||
2745 | + BUG_ON(!S_ISDIR(dentry->d_inode->i_mode)); | ||
2746 | + BUG_ON(bindex < dbstart(dentry)); | ||
2747 | + BUG_ON(bindex > dbend(dentry)); | ||
2748 | + err = is_robranch_super(sb, bindex); | ||
2749 | + if (err) | ||
2750 | + goto out; | ||
2751 | + | ||
2752 | + hidden_dir_dentry = unionfs_lower_dentry_idx(dentry, bindex); | ||
2753 | + BUG_ON(!S_ISDIR(hidden_dir_dentry->d_inode->i_mode)); | ||
2754 | + hidden_dir = hidden_dir_dentry->d_inode; | ||
2755 | + BUG_ON(!S_ISDIR(hidden_dir->i_mode)); | ||
2756 | + | ||
2757 | + mutex_lock(&hidden_dir->i_mutex); | ||
2758 | + if (!permission(hidden_dir, MAY_WRITE | MAY_EXEC, NULL)) | ||
2759 | + err = do_delete_whiteouts(dentry, bindex, namelist); | ||
2760 | + else { | ||
2761 | + args.deletewh.namelist = namelist; | ||
2762 | + args.deletewh.dentry = dentry; | ||
2763 | + args.deletewh.bindex = bindex; | ||
2764 | + run_sioq(__delete_whiteouts, &args); | ||
2765 | + err = args.err; | ||
2766 | + } | ||
2767 | + mutex_unlock(&hidden_dir->i_mutex); | ||
2768 | + | ||
2769 | +out: | ||
2770 | + unionfs_read_unlock(sb); | ||
2771 | + return err; | ||
2772 | +} | ||
2773 | + | ||
2774 | +#define RD_NONE 0 | ||
2775 | +#define RD_CHECK_EMPTY 1 | ||
2776 | +/* The callback structure for check_empty. */ | ||
2777 | +struct unionfs_rdutil_callback { | ||
2778 | + int err; | ||
2779 | + int filldir_called; | ||
2780 | + struct unionfs_dir_state *rdstate; | ||
2781 | + int mode; | ||
2782 | +}; | ||
2783 | + | ||
2784 | +/* This filldir function makes sure only whiteouts exist within a directory. */ | ||
2785 | +static int readdir_util_callback(void *dirent, const char *name, int namelen, | ||
2786 | + loff_t offset, u64 ino, unsigned int d_type) | ||
2787 | +{ | ||
2788 | + int err = 0; | ||
2789 | + struct unionfs_rdutil_callback *buf = dirent; | ||
2790 | + int whiteout = 0; | ||
2791 | + struct filldir_node *found; | ||
2792 | + | ||
2793 | + buf->filldir_called = 1; | ||
2794 | + | ||
2795 | + if (name[0] == '.' && (namelen == 1 || (name[1] == '.' && namelen == 2))) | ||
2796 | + goto out; | ||
2797 | + | ||
2798 | + if (namelen > UNIONFS_WHLEN && | ||
2799 | + !strncmp(name, UNIONFS_WHPFX, UNIONFS_WHLEN)) { | ||
2800 | + namelen -= UNIONFS_WHLEN; | ||
2801 | + name += UNIONFS_WHLEN; | ||
2802 | + whiteout = 1; | ||
2803 | + } | ||
2804 | + | ||
2805 | + found = find_filldir_node(buf->rdstate, name, namelen); | ||
2806 | + /* If it was found in the table there was a previous whiteout. */ | ||
2807 | + if (found) | ||
2808 | + goto out; | ||
2809 | + | ||
2810 | + /* If it wasn't found and isn't a whiteout, the directory isn't empty. */ | ||
2811 | + err = -ENOTEMPTY; | ||
2812 | + if ((buf->mode == RD_CHECK_EMPTY) && !whiteout) | ||
2813 | + goto out; | ||
2814 | + | ||
2815 | + err = add_filldir_node(buf->rdstate, name, namelen, | ||
2816 | + buf->rdstate->bindex, whiteout); | ||
2817 | + | ||
2818 | +out: | ||
2819 | + buf->err = err; | ||
2820 | + return err; | ||
2821 | +} | ||
2822 | + | ||
2823 | +/* Is a directory logically empty? */ | ||
2824 | +int check_empty(struct dentry *dentry, struct unionfs_dir_state **namelist) | ||
2825 | +{ | ||
2826 | + int err = 0; | ||
2827 | + struct dentry *hidden_dentry = NULL; | ||
2828 | + struct super_block *sb; | ||
2829 | + struct file *hidden_file; | ||
2830 | + struct unionfs_rdutil_callback *buf = NULL; | ||
2831 | + int bindex, bstart, bend, bopaque; | ||
2832 | + | ||
2833 | + sb = dentry->d_sb; | ||
2834 | + | ||
2835 | + unionfs_read_lock(sb); | ||
2836 | + | ||
2837 | + BUG_ON(!S_ISDIR(dentry->d_inode->i_mode)); | ||
2838 | + | ||
2839 | + if ((err = unionfs_partial_lookup(dentry))) | ||
2840 | + goto out; | ||
2841 | + | ||
2842 | + bstart = dbstart(dentry); | ||
2843 | + bend = dbend(dentry); | ||
2844 | + bopaque = dbopaque(dentry); | ||
2845 | + if (0 <= bopaque && bopaque < bend) | ||
2846 | + bend = bopaque; | ||
2847 | + | ||
2848 | + buf = kmalloc(sizeof(struct unionfs_rdutil_callback), GFP_KERNEL); | ||
2849 | + if (!buf) { | ||
2850 | + err = -ENOMEM; | ||
2851 | + goto out; | ||
2852 | + } | ||
2853 | + buf->err = 0; | ||
2854 | + buf->mode = RD_CHECK_EMPTY; | ||
2855 | + buf->rdstate = alloc_rdstate(dentry->d_inode, bstart); | ||
2856 | + if (!buf->rdstate) { | ||
2857 | + err = -ENOMEM; | ||
2858 | + goto out; | ||
2859 | + } | ||
2860 | + | ||
2861 | + /* Process the hidden directories with rdutil_callback as a filldir. */ | ||
2862 | + for (bindex = bstart; bindex <= bend; bindex++) { | ||
2863 | + hidden_dentry = unionfs_lower_dentry_idx(dentry, bindex); | ||
2864 | + if (!hidden_dentry) | ||
2865 | + continue; | ||
2866 | + if (!hidden_dentry->d_inode) | ||
2867 | + continue; | ||
2868 | + if (!S_ISDIR(hidden_dentry->d_inode->i_mode)) | ||
2869 | + continue; | ||
2870 | + | ||
2871 | + dget(hidden_dentry); | ||
2872 | + unionfs_mntget(dentry, bindex); | ||
2873 | + unionfs_read_lock(sb); | ||
2874 | + branchget(sb, bindex); | ||
2875 | + unionfs_read_unlock(sb); | ||
2876 | + hidden_file = | ||
2877 | + dentry_open(hidden_dentry, unionfs_lower_mnt_idx(dentry, bindex), | ||
2878 | + O_RDONLY); | ||
2879 | + if (IS_ERR(hidden_file)) { | ||
2880 | + err = PTR_ERR(hidden_file); | ||
2881 | + dput(hidden_dentry); | ||
2882 | + unionfs_read_lock(sb); | ||
2883 | + branchput(sb, bindex); | ||
2884 | + unionfs_read_unlock(sb); | ||
2885 | + goto out; | ||
2886 | + } | ||
2887 | + | ||
2888 | + do { | ||
2889 | + buf->filldir_called = 0; | ||
2890 | + buf->rdstate->bindex = bindex; | ||
2891 | + err = vfs_readdir(hidden_file, | ||
2892 | + readdir_util_callback, buf); | ||
2893 | + if (buf->err) | ||
2894 | + err = buf->err; | ||
2895 | + } while ((err >= 0) && buf->filldir_called); | ||
2896 | + | ||
2897 | + /* fput calls dput for hidden_dentry */ | ||
2898 | + fput(hidden_file); | ||
2899 | + unionfs_read_lock(sb); | ||
2900 | + branchput(sb, bindex); | ||
2901 | + unionfs_read_unlock(sb); | ||
2902 | + | ||
2903 | + if (err < 0) | ||
2904 | + goto out; | ||
2905 | + } | ||
2906 | + | ||
2907 | +out: | ||
2908 | + if (buf) { | ||
2909 | + if (namelist && !err) | ||
2910 | + *namelist = buf->rdstate; | ||
2911 | + else if (buf->rdstate) | ||
2912 | + free_rdstate(buf->rdstate); | ||
2913 | + kfree(buf); | ||
2914 | + } | ||
2915 | + | ||
2916 | + unionfs_read_unlock(sb); | ||
2917 | + | ||
2918 | + return err; | ||
2919 | +} | ||
2920 | + | ||
2921 | diff --git a/fs/unionfs/fanout.h b/fs/unionfs/fanout.h | ||
2922 | new file mode 100644 | ||
2923 | index 0000000..9e4a35f | ||
2924 | --- /dev/null | ||
2925 | +++ b/fs/unionfs/fanout.h | ||
2926 | @@ -0,0 +1,231 @@ | ||
2927 | +/* | ||
2928 | + * Copyright (c) 2003-2007 Erez Zadok | ||
2929 | + * Copyright (c) 2003-2006 Charles P. Wright | ||
2930 | + * Copyright (c) 2005-2007 Josef 'Jeff' Sipek | ||
2931 | + * Copyright (c) 2005 Arun M. Krishnakumar | ||
2932 | + * Copyright (c) 2004-2006 David P. Quigley | ||
2933 | + * Copyright (c) 2003-2004 Mohammad Nayyer Zubair | ||
2934 | + * Copyright (c) 2003 Puja Gupta | ||
2935 | + * Copyright (c) 2003 Harikesavan Krishnan | ||
2936 | + * Copyright (c) 2003-2007 Stony Brook University | ||
2937 | + * Copyright (c) 2003-2007 The Research Foundation of State University of New York | ||
2938 | + * | ||
2939 | + * This program is free software; you can redistribute it and/or modify | ||
2940 | + * it under the terms of the GNU General Public License version 2 as | ||
2941 | + * published by the Free Software Foundation. | ||
2942 | + */ | ||
2943 | + | ||
2944 | +#ifndef _FANOUT_H_ | ||
2945 | +#define _FANOUT_H_ | ||
2946 | + | ||
2947 | +/* Inode to private data */ | ||
2948 | +static inline struct unionfs_inode_info *UNIONFS_I(const struct inode *inode) | ||
2949 | +{ | ||
2950 | + return container_of(inode, struct unionfs_inode_info, vfs_inode); | ||
2951 | +} | ||
2952 | + | ||
2953 | +#define ibstart(ino) (UNIONFS_I(ino)->bstart) | ||
2954 | +#define ibend(ino) (UNIONFS_I(ino)->bend) | ||
2955 | + | ||
2956 | +/* Superblock to private data */ | ||
2957 | +#define UNIONFS_SB(super) ((struct unionfs_sb_info *)(super)->s_fs_info) | ||
2958 | +#define sbstart(sb) 0 | ||
2959 | +#define sbend(sb) (UNIONFS_SB(sb)->bend) | ||
2960 | +#define sbmax(sb) (UNIONFS_SB(sb)->bend + 1) | ||
2961 | +#define sbhbid(sb) (UNIONFS_SB(sb)->high_branch_id) | ||
2962 | + | ||
2963 | +/* File to private Data */ | ||
2964 | +#define UNIONFS_F(file) ((struct unionfs_file_info *)((file)->private_data)) | ||
2965 | +#define fbstart(file) (UNIONFS_F(file)->bstart) | ||
2966 | +#define fbend(file) (UNIONFS_F(file)->bend) | ||
2967 | + | ||
2968 | +/* macros to manipulate branch IDs in stored in our superblock */ | ||
2969 | +static inline int branch_id(struct super_block *sb, int index) | ||
2970 | +{ | ||
2971 | + return UNIONFS_SB(sb)->data[index].branch_id; | ||
2972 | +} | ||
2973 | + | ||
2974 | +static inline void set_branch_id(struct super_block *sb, int index, int val) | ||
2975 | +{ | ||
2976 | + UNIONFS_SB(sb)->data[index].branch_id = val; | ||
2977 | +} | ||
2978 | + | ||
2979 | +static inline void new_branch_id(struct super_block *sb, int index) | ||
2980 | +{ | ||
2981 | + set_branch_id(sb, index, ++UNIONFS_SB(sb)->high_branch_id); | ||
2982 | +} | ||
2983 | + | ||
2984 | +/* File to lower file. */ | ||
2985 | +static inline struct file *unionfs_lower_file(const struct file *f) | ||
2986 | +{ | ||
2987 | + return UNIONFS_F(f)->lower_files[fbstart(f)]; | ||
2988 | +} | ||
2989 | + | ||
2990 | +static inline struct file *unionfs_lower_file_idx(const struct file *f, int index) | ||
2991 | +{ | ||
2992 | + return UNIONFS_F(f)->lower_files[index]; | ||
2993 | +} | ||
2994 | + | ||
2995 | +static inline void unionfs_set_lower_file_idx(struct file *f, int index, struct file *val) | ||
2996 | +{ | ||
2997 | + UNIONFS_F(f)->lower_files[index] = val; | ||
2998 | + /* save branch ID (may be redundant?) */ | ||
2999 | + UNIONFS_F(f)->saved_branch_ids[index] = | ||
3000 | + branch_id((f)->f_dentry->d_sb, index); | ||
3001 | +} | ||
3002 | + | ||
3003 | +static inline void unionfs_set_lower_file(struct file *f, struct file *val) | ||
3004 | +{ | ||
3005 | + unionfs_set_lower_file_idx((f), fbstart(f), (val)); | ||
3006 | +} | ||
3007 | + | ||
3008 | +/* Inode to lower inode. */ | ||
3009 | +static inline struct inode *unionfs_lower_inode(const struct inode *i) | ||
3010 | +{ | ||
3011 | + return UNIONFS_I(i)->lower_inodes[ibstart(i)]; | ||
3012 | +} | ||
3013 | + | ||
3014 | +static inline struct inode *unionfs_lower_inode_idx(const struct inode *i, int index) | ||
3015 | +{ | ||
3016 | + return UNIONFS_I(i)->lower_inodes[index]; | ||
3017 | +} | ||
3018 | + | ||
3019 | +static inline void unionfs_set_lower_inode_idx(struct inode *i, int index, | ||
3020 | + struct inode *val) | ||
3021 | +{ | ||
3022 | + UNIONFS_I(i)->lower_inodes[index] = val; | ||
3023 | +} | ||
3024 | + | ||
3025 | +static inline void unionfs_set_lower_inode(struct inode *i, struct inode *val) | ||
3026 | +{ | ||
3027 | + UNIONFS_I(i)->lower_inodes[ibstart(i)] = val; | ||
3028 | +} | ||
3029 | + | ||
3030 | +/* Superblock to lower superblock. */ | ||
3031 | +static inline struct super_block *unionfs_lower_super(const struct super_block *sb) | ||
3032 | +{ | ||
3033 | + return UNIONFS_SB(sb)->data[sbstart(sb)].sb; | ||
3034 | +} | ||
3035 | + | ||
3036 | +static inline struct super_block *unionfs_lower_super_idx(const struct super_block *sb, int index) | ||
3037 | +{ | ||
3038 | + return UNIONFS_SB(sb)->data[index].sb; | ||
3039 | +} | ||
3040 | + | ||
3041 | +static inline void unionfs_set_lower_super_idx(struct super_block *sb, int index, | ||
3042 | + struct super_block *val) | ||
3043 | +{ | ||
3044 | + UNIONFS_SB(sb)->data[index].sb = val; | ||
3045 | +} | ||
3046 | + | ||
3047 | +static inline void unionfs_set_lower_super(struct super_block *sb, struct super_block *val) | ||
3048 | +{ | ||
3049 | + UNIONFS_SB(sb)->data[sbstart(sb)].sb = val; | ||
3050 | +} | ||
3051 | + | ||
3052 | +/* Branch count macros. */ | ||
3053 | +static inline int branch_count(const struct super_block *sb, int index) | ||
3054 | +{ | ||
3055 | + return atomic_read(&UNIONFS_SB(sb)->data[index].open_files); | ||
3056 | +} | ||
3057 | + | ||
3058 | +static inline void set_branch_count(struct super_block *sb, int index, int val) | ||
3059 | +{ | ||
3060 | + atomic_set(&UNIONFS_SB(sb)->data[index].open_files, val); | ||
3061 | +} | ||
3062 | + | ||
3063 | +static inline void branchget(struct super_block *sb, int index) | ||
3064 | +{ | ||
3065 | + atomic_inc(&UNIONFS_SB(sb)->data[index].open_files); | ||
3066 | +} | ||
3067 | + | ||
3068 | +static inline void branchput(struct super_block *sb, int index) | ||
3069 | +{ | ||
3070 | + atomic_dec(&UNIONFS_SB(sb)->data[index].open_files); | ||
3071 | +} | ||
3072 | + | ||
3073 | +/* Dentry macros */ | ||
3074 | +static inline struct unionfs_dentry_info *UNIONFS_D(const struct dentry *dent) | ||
3075 | +{ | ||
3076 | + return dent->d_fsdata; | ||
3077 | +} | ||
3078 | + | ||
3079 | +static inline int dbstart(const struct dentry *dent) | ||
3080 | +{ | ||
3081 | + return UNIONFS_D(dent)->bstart; | ||
3082 | +} | ||
3083 | + | ||
3084 | +static inline void set_dbstart(struct dentry *dent, int val) | ||
3085 | +{ | ||
3086 | + UNIONFS_D(dent)->bstart = val; | ||
3087 | +} | ||
3088 | + | ||
3089 | +static inline int dbend(const struct dentry *dent) | ||
3090 | +{ | ||
3091 | + return UNIONFS_D(dent)->bend; | ||
3092 | +} | ||
3093 | + | ||
3094 | +static inline void set_dbend(struct dentry *dent, int val) | ||
3095 | +{ | ||
3096 | + UNIONFS_D(dent)->bend = val; | ||
3097 | +} | ||
3098 | + | ||
3099 | +static inline int dbopaque(const struct dentry *dent) | ||
3100 | +{ | ||
3101 | + return UNIONFS_D(dent)->bopaque; | ||
3102 | +} | ||
3103 | + | ||
3104 | +static inline void set_dbopaque(struct dentry *dent, int val) | ||
3105 | +{ | ||
3106 | + UNIONFS_D(dent)->bopaque = val; | ||
3107 | +} | ||
3108 | + | ||
3109 | +static inline void unionfs_set_lower_dentry_idx(struct dentry *dent, int index, | ||
3110 | + struct dentry *val) | ||
3111 | +{ | ||
3112 | + UNIONFS_D(dent)->lower_paths[index].dentry = val; | ||
3113 | +} | ||
3114 | + | ||
3115 | +static inline struct dentry *unionfs_lower_dentry_idx(const struct dentry *dent, int index) | ||
3116 | +{ | ||
3117 | + return UNIONFS_D(dent)->lower_paths[index].dentry; | ||
3118 | +} | ||
3119 | + | ||
3120 | +static inline struct dentry *unionfs_lower_dentry(const struct dentry *dent) | ||
3121 | +{ | ||
3122 | + return unionfs_lower_dentry_idx(dent, dbstart(dent)); | ||
3123 | +} | ||
3124 | + | ||
3125 | +static inline void unionfs_set_lower_mnt_idx(struct dentry *dent, int index, | ||
3126 | + struct vfsmount *mnt) | ||
3127 | +{ | ||
3128 | + UNIONFS_D(dent)->lower_paths[index].mnt = mnt; | ||
3129 | +} | ||
3130 | + | ||
3131 | +static inline struct vfsmount *unionfs_lower_mnt_idx(const struct dentry *dent, int index) | ||
3132 | +{ | ||
3133 | + return UNIONFS_D(dent)->lower_paths[index].mnt; | ||
3134 | +} | ||
3135 | + | ||
3136 | +static inline struct vfsmount *unionfs_lower_mnt(const struct dentry *dent) | ||
3137 | +{ | ||
3138 | + return unionfs_lower_mnt_idx(dent,dbstart(dent)); | ||
3139 | +} | ||
3140 | + | ||
3141 | +/* Macros for locking a dentry. */ | ||
3142 | +static inline void unionfs_lock_dentry(struct dentry *d) | ||
3143 | +{ | ||
3144 | + mutex_lock(&UNIONFS_D(d)->lock); | ||
3145 | +} | ||
3146 | + | ||
3147 | +static inline void unionfs_unlock_dentry(struct dentry *d) | ||
3148 | +{ | ||
3149 | + mutex_unlock(&UNIONFS_D(d)->lock); | ||
3150 | +} | ||
3151 | + | ||
3152 | +static inline void verify_locked(struct dentry *d) | ||
3153 | +{ | ||
3154 | + BUG_ON(!mutex_is_locked(&UNIONFS_D(d)->lock)); | ||
3155 | +} | ||
3156 | + | ||
3157 | +#endif /* _FANOUT_H */ | ||
3158 | diff --git a/fs/unionfs/file.c b/fs/unionfs/file.c | ||
3159 | new file mode 100644 | ||
3160 | index 0000000..84d6bab | ||
3161 | --- /dev/null | ||
3162 | +++ b/fs/unionfs/file.c | ||
3163 | @@ -0,0 +1,266 @@ | ||
3164 | +/* | ||
3165 | + * Copyright (c) 2003-2007 Erez Zadok | ||
3166 | + * Copyright (c) 2003-2006 Charles P. Wright | ||
3167 | + * Copyright (c) 2005-2007 Josef 'Jeff' Sipek | ||
3168 | + * Copyright (c) 2005-2006 Junjiro Okajima | ||
3169 | + * Copyright (c) 2005 Arun M. Krishnakumar | ||
3170 | + * Copyright (c) 2004-2006 David P. Quigley | ||
3171 | + * Copyright (c) 2003-2004 Mohammad Nayyer Zubair | ||
3172 | + * Copyright (c) 2003 Puja Gupta | ||
3173 | + * Copyright (c) 2003 Harikesavan Krishnan | ||
3174 | + * Copyright (c) 2003-2007 Stony Brook University | ||
3175 | + * Copyright (c) 2003-2007 The Research Foundation of State University of New York | ||
3176 | + * | ||
3177 | + * This program is free software; you can redistribute it and/or modify | ||
3178 | + * it under the terms of the GNU General Public License version 2 as | ||
3179 | + * published by the Free Software Foundation. | ||
3180 | + */ | ||
3181 | + | ||
3182 | +#include "union.h" | ||
3183 | + | ||
3184 | +/******************* | ||
3185 | + * File Operations * | ||
3186 | + *******************/ | ||
3187 | + | ||
3188 | +static loff_t unionfs_llseek(struct file *file, loff_t offset, int origin) | ||
3189 | +{ | ||
3190 | + loff_t err; | ||
3191 | + struct file *hidden_file = NULL; | ||
3192 | + | ||
3193 | + unionfs_read_lock(file->f_dentry->d_sb); | ||
3194 | + if ((err = unionfs_file_revalidate(file, 0))) | ||
3195 | + goto out; | ||
3196 | + | ||
3197 | + hidden_file = unionfs_lower_file(file); | ||
3198 | + /* always set hidden position to this one */ | ||
3199 | + hidden_file->f_pos = file->f_pos; | ||
3200 | + | ||
3201 | + memcpy(&hidden_file->f_ra, &file->f_ra, sizeof(struct file_ra_state)); | ||
3202 | + | ||
3203 | + if (hidden_file->f_op && hidden_file->f_op->llseek) | ||
3204 | + err = hidden_file->f_op->llseek(hidden_file, offset, origin); | ||
3205 | + else | ||
3206 | + err = generic_file_llseek(hidden_file, offset, origin); | ||
3207 | + | ||
3208 | + if (err < 0) | ||
3209 | + goto out; | ||
3210 | + if (err != file->f_pos) { | ||
3211 | + file->f_pos = err; | ||
3212 | + file->f_version++; | ||
3213 | + } | ||
3214 | +out: | ||
3215 | + unionfs_read_unlock(file->f_dentry->d_sb); | ||
3216 | + return err; | ||
3217 | +} | ||
3218 | + | ||
3219 | +static ssize_t unionfs_read(struct file * file, char __user * buf, | ||
3220 | + size_t count, loff_t * ppos) | ||
3221 | +{ | ||
3222 | + struct file *hidden_file; | ||
3223 | + loff_t pos = *ppos; | ||
3224 | + int err; | ||
3225 | + | ||
3226 | + unionfs_read_lock(file->f_dentry->d_sb); | ||
3227 | + if ((err = unionfs_file_revalidate(file, 0))) | ||
3228 | + goto out; | ||
3229 | + | ||
3230 | + err = -EINVAL; | ||
3231 | + hidden_file = unionfs_lower_file(file); | ||
3232 | + if (!hidden_file->f_op || !hidden_file->f_op->read) | ||
3233 | + goto out; | ||
3234 | + | ||
3235 | + err = hidden_file->f_op->read(hidden_file, buf, count, &pos); | ||
3236 | + *ppos = pos; | ||
3237 | + | ||
3238 | +out: | ||
3239 | + unionfs_read_unlock(file->f_dentry->d_sb); | ||
3240 | + return err; | ||
3241 | +} | ||
3242 | + | ||
3243 | +static ssize_t __unionfs_write(struct file * file, const char __user * buf, | ||
3244 | + size_t count, loff_t * ppos) | ||
3245 | +{ | ||
3246 | + int err = -EINVAL; | ||
3247 | + struct file *hidden_file = NULL; | ||
3248 | + struct inode *inode; | ||
3249 | + struct inode *hidden_inode; | ||
3250 | + loff_t pos = *ppos; | ||
3251 | + int bstart, bend; | ||
3252 | + | ||
3253 | + inode = file->f_dentry->d_inode; | ||
3254 | + | ||
3255 | + bstart = fbstart(file); | ||
3256 | + bend = fbend(file); | ||
3257 | + | ||
3258 | + BUG_ON(bstart == -1); | ||
3259 | + | ||
3260 | + hidden_file = unionfs_lower_file(file); | ||
3261 | + hidden_inode = hidden_file->f_dentry->d_inode; | ||
3262 | + | ||
3263 | + if (!hidden_file->f_op || !hidden_file->f_op->write) | ||
3264 | + goto out; | ||
3265 | + | ||
3266 | + /* adjust for append -- seek to the end of the file */ | ||
3267 | + if (file->f_flags & O_APPEND) | ||
3268 | + pos = inode->i_size; | ||
3269 | + | ||
3270 | + err = hidden_file->f_op->write(hidden_file, buf, count, &pos); | ||
3271 | + | ||
3272 | + /* | ||
3273 | + * copy ctime and mtime from lower layer attributes | ||
3274 | + * atime is unchanged for both layers | ||
3275 | + */ | ||
3276 | + if (err >= 0) | ||
3277 | + fsstack_copy_attr_times(inode, hidden_inode); | ||
3278 | + | ||
3279 | + *ppos = pos; | ||
3280 | + | ||
3281 | + /* update this inode's size */ | ||
3282 | + if (pos > inode->i_size) | ||
3283 | + inode->i_size = pos; | ||
3284 | +out: | ||
3285 | + return err; | ||
3286 | +} | ||
3287 | + | ||
3288 | +static ssize_t unionfs_write(struct file * file, const char __user * buf, | ||
3289 | + size_t count, loff_t * ppos) | ||
3290 | +{ | ||
3291 | + int err = 0; | ||
3292 | + | ||
3293 | + unionfs_read_lock(file->f_dentry->d_sb); | ||
3294 | + if ((err = unionfs_file_revalidate(file, 1))) | ||
3295 | + goto out; | ||
3296 | + | ||
3297 | + err = __unionfs_write(file, buf, count, ppos); | ||
3298 | + | ||
3299 | +out: | ||
3300 | + unionfs_read_unlock(file->f_dentry->d_sb); | ||
3301 | + return err; | ||
3302 | +} | ||
3303 | + | ||
3304 | +static int unionfs_file_readdir(struct file *file, void *dirent, | ||
3305 | + filldir_t filldir) | ||
3306 | +{ | ||
3307 | + return -ENOTDIR; | ||
3308 | +} | ||
3309 | + | ||
3310 | +static unsigned int unionfs_poll(struct file *file, poll_table * wait) | ||
3311 | +{ | ||
3312 | + unsigned int mask = DEFAULT_POLLMASK; | ||
3313 | + struct file *hidden_file = NULL; | ||
3314 | + | ||
3315 | + unionfs_read_lock(file->f_dentry->d_sb); | ||
3316 | + if (unionfs_file_revalidate(file, 0)) { | ||
3317 | + /* We should pretend an error happend. */ | ||
3318 | + mask = POLLERR | POLLIN | POLLOUT; | ||
3319 | + goto out; | ||
3320 | + } | ||
3321 | + | ||
3322 | + hidden_file = unionfs_lower_file(file); | ||
3323 | + | ||
3324 | + if (!hidden_file->f_op || !hidden_file->f_op->poll) | ||
3325 | + goto out; | ||
3326 | + | ||
3327 | + mask = hidden_file->f_op->poll(hidden_file, wait); | ||
3328 | + | ||
3329 | +out: | ||
3330 | + unionfs_read_unlock(file->f_dentry->d_sb); | ||
3331 | + return mask; | ||
3332 | +} | ||
3333 | + | ||
3334 | +static int __do_mmap(struct file *file, struct vm_area_struct *vma) | ||
3335 | +{ | ||
3336 | + int err; | ||
3337 | + struct file *hidden_file; | ||
3338 | + | ||
3339 | + hidden_file = unionfs_lower_file(file); | ||
3340 | + | ||
3341 | + err = -ENODEV; | ||
3342 | + if (!hidden_file->f_op || !hidden_file->f_op->mmap) | ||
3343 | + goto out; | ||
3344 | + | ||
3345 | + vma->vm_file = hidden_file; | ||
3346 | + err = hidden_file->f_op->mmap(hidden_file, vma); | ||
3347 | + get_file(hidden_file); /* make sure it doesn't get freed on us */ | ||
3348 | + fput(file); /* no need to keep extra ref on ours */ | ||
3349 | +out: | ||
3350 | + return err; | ||
3351 | +} | ||
3352 | + | ||
3353 | +static int unionfs_mmap(struct file *file, struct vm_area_struct *vma) | ||
3354 | +{ | ||
3355 | + int err = 0; | ||
3356 | + int willwrite; | ||
3357 | + | ||
3358 | + unionfs_read_lock(file->f_dentry->d_sb); | ||
3359 | + /* This might could be deferred to mmap's writepage. */ | ||
3360 | + willwrite = ((vma->vm_flags | VM_SHARED | VM_WRITE) == vma->vm_flags); | ||
3361 | + if ((err = unionfs_file_revalidate(file, willwrite))) | ||
3362 | + goto out; | ||
3363 | + | ||
3364 | + err = __do_mmap(file, vma); | ||
3365 | + | ||
3366 | +out: | ||
3367 | + unionfs_read_unlock(file->f_dentry->d_sb); | ||
3368 | + return err; | ||
3369 | +} | ||
3370 | + | ||
3371 | +static int unionfs_fsync(struct file *file, struct dentry *dentry, int datasync) | ||
3372 | +{ | ||
3373 | + int err; | ||
3374 | + struct file *hidden_file = NULL; | ||
3375 | + | ||
3376 | + unionfs_read_lock(file->f_dentry->d_sb); | ||
3377 | + if ((err = unionfs_file_revalidate(file, 1))) | ||
3378 | + goto out; | ||
3379 | + | ||
3380 | + hidden_file = unionfs_lower_file(file); | ||
3381 | + | ||
3382 | + err = -EINVAL; | ||
3383 | + if (!hidden_file->f_op || !hidden_file->f_op->fsync) | ||
3384 | + goto out; | ||
3385 | + | ||
3386 | + mutex_lock(&hidden_file->f_dentry->d_inode->i_mutex); | ||
3387 | + err = hidden_file->f_op->fsync(hidden_file, hidden_file->f_dentry, | ||
3388 | + datasync); | ||
3389 | + mutex_unlock(&hidden_file->f_dentry->d_inode->i_mutex); | ||
3390 | + | ||
3391 | +out: | ||
3392 | + unionfs_read_unlock(file->f_dentry->d_sb); | ||
3393 | + return err; | ||
3394 | +} | ||
3395 | + | ||
3396 | +static int unionfs_fasync(int fd, struct file *file, int flag) | ||
3397 | +{ | ||
3398 | + int err = 0; | ||
3399 | + struct file *hidden_file = NULL; | ||
3400 | + | ||
3401 | + unionfs_read_lock(file->f_dentry->d_sb); | ||
3402 | + if ((err = unionfs_file_revalidate(file, 1))) | ||
3403 | + goto out; | ||
3404 | + | ||
3405 | + hidden_file = unionfs_lower_file(file); | ||
3406 | + | ||
3407 | + if (hidden_file->f_op && hidden_file->f_op->fasync) | ||
3408 | + err = hidden_file->f_op->fasync(fd, hidden_file, flag); | ||
3409 | + | ||
3410 | +out: | ||
3411 | + unionfs_read_unlock(file->f_dentry->d_sb); | ||
3412 | + return err; | ||
3413 | +} | ||
3414 | + | ||
3415 | +struct file_operations unionfs_main_fops = { | ||
3416 | + .llseek = unionfs_llseek, | ||
3417 | + .read = unionfs_read, | ||
3418 | + .write = unionfs_write, | ||
3419 | + .readdir = unionfs_file_readdir, | ||
3420 | + .poll = unionfs_poll, | ||
3421 | + .unlocked_ioctl = unionfs_ioctl, | ||
3422 | + .mmap = unionfs_mmap, | ||
3423 | + .open = unionfs_open, | ||
3424 | + .flush = unionfs_flush, | ||
3425 | + .release = unionfs_file_release, | ||
3426 | + .fsync = unionfs_fsync, | ||
3427 | + .fasync = unionfs_fasync, | ||
3428 | +}; | ||
3429 | + | ||
3430 | diff --git a/fs/unionfs/inode.c b/fs/unionfs/inode.c | ||
3431 | new file mode 100644 | ||
3432 | index 0000000..97dad8c | ||
3433 | --- /dev/null | ||
3434 | +++ b/fs/unionfs/inode.c | ||
3435 | @@ -0,0 +1,1016 @@ | ||
3436 | +/* | ||
3437 | + * Copyright (c) 2003-2007 Erez Zadok | ||
3438 | + * Copyright (c) 2003-2006 Charles P. Wright | ||
3439 | + * Copyright (c) 2005-2007 Josef 'Jeff' Sipek | ||
3440 | + * Copyright (c) 2005-2006 Junjiro Okajima | ||
3441 | + * Copyright (c) 2005 Arun M. Krishnakumar | ||
3442 | + * Copyright (c) 2004-2006 David P. Quigley | ||
3443 | + * Copyright (c) 2003-2004 Mohammad Nayyer Zubair | ||
3444 | + * Copyright (c) 2003 Puja Gupta | ||
3445 | + * Copyright (c) 2003 Harikesavan Krishnan | ||
3446 | + * Copyright (c) 2003-2007 Stony Brook University | ||
3447 | + * Copyright (c) 2003-2007 The Research Foundation of State University of New York | ||
3448 | + * | ||
3449 | + * This program is free software; you can redistribute it and/or modify | ||
3450 | + * it under the terms of the GNU General Public License version 2 as | ||
3451 | + * published by the Free Software Foundation. | ||
3452 | + */ | ||
3453 | + | ||
3454 | +#include "union.h" | ||
3455 | + | ||
3456 | +static int unionfs_create(struct inode *parent, struct dentry *dentry, | ||
3457 | + int mode, struct nameidata *nd) | ||
3458 | +{ | ||
3459 | + int err = 0; | ||
3460 | + struct dentry *hidden_dentry = NULL; | ||
3461 | + struct dentry *wh_dentry = NULL; | ||
3462 | + struct dentry *new_hidden_dentry; | ||
3463 | + struct dentry *hidden_parent_dentry = NULL; | ||
3464 | + int bindex = 0, bstart; | ||
3465 | + char *name = NULL; | ||
3466 | + int valid = 0; | ||
3467 | + | ||
3468 | + /* | ||
3469 | + * We have to read-lock the superblock rwsem, and we have to | ||
3470 | + * revalidate the parent dentry and this one. A branch-management | ||
3471 | + * operation could have taken place, mid-way through a VFS operation | ||
3472 | + * that eventually reaches here. So we have to ensure consistency, | ||
3473 | + * just as we do with the file operations. | ||
3474 | + * | ||
3475 | + * XXX: we may need to do this for all other inode ops that take a | ||
3476 | + * dentry. | ||
3477 | + */ | ||
3478 | + unionfs_read_lock(dentry->d_sb); | ||
3479 | + unionfs_lock_dentry(dentry); | ||
3480 | + | ||
3481 | + unionfs_lock_dentry(dentry->d_parent); | ||
3482 | + valid = __unionfs_d_revalidate_chain(dentry->d_parent, nd); | ||
3483 | + unionfs_unlock_dentry(dentry->d_parent); | ||
3484 | + if (!valid) { | ||
3485 | + err = -ENOENT; /* same as what real_lookup does */ | ||
3486 | + goto out; | ||
3487 | + } | ||
3488 | + valid = __unionfs_d_revalidate_chain(dentry, nd); | ||
3489 | + /* | ||
3490 | + * It's only a bug if this dentry was not negative and couldn't be | ||
3491 | + * revalidated (shouldn't happen). | ||
3492 | + */ | ||
3493 | + BUG_ON(!valid && dentry->d_inode); | ||
3494 | + | ||
3495 | + /* We start out in the leftmost branch. */ | ||
3496 | + bstart = dbstart(dentry); | ||
3497 | + hidden_dentry = unionfs_lower_dentry(dentry); | ||
3498 | + | ||
3499 | + /* check if whiteout exists in this branch, i.e. lookup .wh.foo first */ | ||
3500 | + name = alloc_whname(dentry->d_name.name, dentry->d_name.len); | ||
3501 | + if (IS_ERR(name)) { | ||
3502 | + err = PTR_ERR(name); | ||
3503 | + goto out; | ||
3504 | + } | ||
3505 | + | ||
3506 | + wh_dentry = lookup_one_len(name, hidden_dentry->d_parent, | ||
3507 | + dentry->d_name.len + UNIONFS_WHLEN); | ||
3508 | + if (IS_ERR(wh_dentry)) { | ||
3509 | + err = PTR_ERR(wh_dentry); | ||
3510 | + wh_dentry = NULL; | ||
3511 | + goto out; | ||
3512 | + } | ||
3513 | + | ||
3514 | + if (wh_dentry->d_inode) { | ||
3515 | + /* .wh.foo has been found. */ | ||
3516 | + /* First truncate it and then rename it to foo (hence having | ||
3517 | + * the same overall effect as a normal create. | ||
3518 | + */ | ||
3519 | + struct dentry *hidden_dir_dentry; | ||
3520 | + struct iattr newattrs; | ||
3521 | + | ||
3522 | + mutex_lock(&wh_dentry->d_inode->i_mutex); | ||
3523 | + newattrs.ia_valid = ATTR_CTIME | ATTR_MODE | ATTR_ATIME | ||
3524 | + | ATTR_MTIME | ATTR_UID | ATTR_GID | ATTR_FORCE | ||
3525 | + | ATTR_KILL_SUID | ATTR_KILL_SGID; | ||
3526 | + | ||
3527 | + newattrs.ia_mode = mode & ~current->fs->umask; | ||
3528 | + newattrs.ia_uid = current->fsuid; | ||
3529 | + newattrs.ia_gid = current->fsgid; | ||
3530 | + | ||
3531 | + if (wh_dentry->d_inode->i_size != 0) { | ||
3532 | + newattrs.ia_valid |= ATTR_SIZE; | ||
3533 | + newattrs.ia_size = 0; | ||
3534 | + } | ||
3535 | + | ||
3536 | + err = notify_change(wh_dentry, &newattrs); | ||
3537 | + | ||
3538 | + mutex_unlock(&wh_dentry->d_inode->i_mutex); | ||
3539 | + | ||
3540 | + if (err) | ||
3541 | + printk(KERN_WARNING "unionfs: %s:%d: notify_change " | ||
3542 | + "failed: %d, ignoring..\n", | ||
3543 | + __FILE__, __LINE__, err); | ||
3544 | + | ||
3545 | + new_hidden_dentry = unionfs_lower_dentry(dentry); | ||
3546 | + dget(new_hidden_dentry); | ||
3547 | + | ||
3548 | + hidden_dir_dentry = dget_parent(wh_dentry); | ||
3549 | + lock_rename(hidden_dir_dentry, hidden_dir_dentry); | ||
3550 | + | ||
3551 | + if (!(err = is_robranch_super(dentry->d_sb, bstart))) { | ||
3552 | + err = vfs_rename(hidden_dir_dentry->d_inode, | ||
3553 | + wh_dentry, | ||
3554 | + hidden_dir_dentry->d_inode, | ||
3555 | + new_hidden_dentry); | ||
3556 | + } | ||
3557 | + if (!err) { | ||
3558 | + fsstack_copy_attr_times(parent, | ||
3559 | + new_hidden_dentry->d_parent->d_inode); | ||
3560 | + fsstack_copy_inode_size(parent, | ||
3561 | + new_hidden_dentry->d_parent->d_inode); | ||
3562 | + parent->i_nlink = unionfs_get_nlinks(parent); | ||
3563 | + } | ||
3564 | + | ||
3565 | + unlock_rename(hidden_dir_dentry, hidden_dir_dentry); | ||
3566 | + dput(hidden_dir_dentry); | ||
3567 | + | ||
3568 | + dput(new_hidden_dentry); | ||
3569 | + | ||
3570 | + if (err) { | ||
3571 | + /* exit if the error returned was NOT -EROFS */ | ||
3572 | + if (!IS_COPYUP_ERR(err)) | ||
3573 | + goto out; | ||
3574 | + /* We were not able to create the file in this | ||
3575 | + * branch, so, we try to create it in one branch to | ||
3576 | + * left | ||
3577 | + */ | ||
3578 | + bstart--; | ||
3579 | + } else { | ||
3580 | + /* reset the unionfs dentry to point to the .wh.foo | ||
3581 | + * entry. | ||
3582 | + */ | ||
3583 | + | ||
3584 | + /* Discard any old reference. */ | ||
3585 | + dput(unionfs_lower_dentry(dentry)); | ||
3586 | + | ||
3587 | + /* Trade one reference to another. */ | ||
3588 | + unionfs_set_lower_dentry_idx(dentry, bstart, wh_dentry); | ||
3589 | + wh_dentry = NULL; | ||
3590 | + | ||
3591 | + err = unionfs_interpose(dentry, parent->i_sb, 0); | ||
3592 | + goto out; | ||
3593 | + } | ||
3594 | + } | ||
3595 | + | ||
3596 | + for (bindex = bstart; bindex >= 0; bindex--) { | ||
3597 | + hidden_dentry = unionfs_lower_dentry_idx(dentry, bindex); | ||
3598 | + if (!hidden_dentry) { | ||
3599 | + /* if hidden_dentry is NULL, create the entire | ||
3600 | + * dentry directory structure in branch 'bindex'. | ||
3601 | + * hidden_dentry will NOT be null when bindex == bstart | ||
3602 | + * because lookup passed as a negative unionfs dentry | ||
3603 | + * pointing to a lone negative underlying dentry */ | ||
3604 | + hidden_dentry = create_parents(parent, dentry, bindex); | ||
3605 | + if (!hidden_dentry || IS_ERR(hidden_dentry)) { | ||
3606 | + if (IS_ERR(hidden_dentry)) | ||
3607 | + err = PTR_ERR(hidden_dentry); | ||
3608 | + continue; | ||
3609 | + } | ||
3610 | + } | ||
3611 | + | ||
3612 | + hidden_parent_dentry = lock_parent(hidden_dentry); | ||
3613 | + if (IS_ERR(hidden_parent_dentry)) { | ||
3614 | + err = PTR_ERR(hidden_parent_dentry); | ||
3615 | + goto out; | ||
3616 | + } | ||
3617 | + /* We shouldn't create things in a read-only branch. */ | ||
3618 | + if (!(err = is_robranch_super(dentry->d_sb, bindex))) | ||
3619 | + err = vfs_create(hidden_parent_dentry->d_inode, | ||
3620 | + hidden_dentry, mode, nd); | ||
3621 | + | ||
3622 | + if (err || !hidden_dentry->d_inode) { | ||
3623 | + unlock_dir(hidden_parent_dentry); | ||
3624 | + | ||
3625 | + /* break out of for loop if the error wasn't -EROFS */ | ||
3626 | + if (!IS_COPYUP_ERR(err)) | ||
3627 | + break; | ||
3628 | + } else { | ||
3629 | + err = unionfs_interpose(dentry, parent->i_sb, 0); | ||
3630 | + if (!err) { | ||
3631 | + fsstack_copy_attr_times(parent, | ||
3632 | + hidden_parent_dentry->d_inode); | ||
3633 | + fsstack_copy_inode_size(parent, | ||
3634 | + hidden_parent_dentry->d_inode); | ||
3635 | + /* update number of links on parent directory */ | ||
3636 | + parent->i_nlink = unionfs_get_nlinks(parent); | ||
3637 | + } | ||
3638 | + unlock_dir(hidden_parent_dentry); | ||
3639 | + break; | ||
3640 | + } | ||
3641 | + } | ||
3642 | + | ||
3643 | +out: | ||
3644 | + dput(wh_dentry); | ||
3645 | + kfree(name); | ||
3646 | + | ||
3647 | + unionfs_unlock_dentry(dentry); | ||
3648 | + unionfs_read_unlock(dentry->d_sb); | ||
3649 | + return err; | ||
3650 | +} | ||
3651 | + | ||
3652 | +static struct dentry *unionfs_lookup(struct inode *parent, | ||
3653 | + struct dentry *dentry, | ||
3654 | + struct nameidata *nd) | ||
3655 | +{ | ||
3656 | + struct path path_save; | ||
3657 | + struct dentry *ret; | ||
3658 | + | ||
3659 | + /* save the dentry & vfsmnt from namei */ | ||
3660 | + if (nd) { | ||
3661 | + path_save.dentry = nd->dentry; | ||
3662 | + path_save.mnt = nd->mnt; | ||
3663 | + } | ||
3664 | + | ||
3665 | + /* The locking is done by unionfs_lookup_backend. */ | ||
3666 | + ret = unionfs_lookup_backend(dentry, nd, INTERPOSE_LOOKUP); | ||
3667 | + | ||
3668 | + /* restore the dentry & vfsmnt in namei */ | ||
3669 | + if (nd) { | ||
3670 | + nd->dentry = path_save.dentry; | ||
3671 | + nd->mnt = path_save.mnt; | ||
3672 | + } | ||
3673 | + | ||
3674 | + return ret; | ||
3675 | +} | ||
3676 | + | ||
3677 | +static int unionfs_link(struct dentry *old_dentry, struct inode *dir, | ||
3678 | + struct dentry *new_dentry) | ||
3679 | +{ | ||
3680 | + int err = 0; | ||
3681 | + struct dentry *hidden_old_dentry = NULL; | ||
3682 | + struct dentry *hidden_new_dentry = NULL; | ||
3683 | + struct dentry *hidden_dir_dentry = NULL; | ||
3684 | + struct dentry *whiteout_dentry; | ||
3685 | + char *name = NULL; | ||
3686 | + | ||
3687 | + BUG_ON(!is_valid_dentry(new_dentry)); | ||
3688 | + BUG_ON(!is_valid_dentry(old_dentry)); | ||
3689 | + | ||
3690 | + double_lock_dentry(new_dentry, old_dentry); | ||
3691 | + | ||
3692 | + hidden_new_dentry = unionfs_lower_dentry(new_dentry); | ||
3693 | + | ||
3694 | + /* check if whiteout exists in the branch of new dentry, i.e. lookup | ||
3695 | + * .wh.foo first. If present, delete it | ||
3696 | + */ | ||
3697 | + name = alloc_whname(new_dentry->d_name.name, new_dentry->d_name.len); | ||
3698 | + if (IS_ERR(name)) { | ||
3699 | + err = PTR_ERR(name); | ||
3700 | + goto out; | ||
3701 | + } | ||
3702 | + | ||
3703 | + whiteout_dentry = lookup_one_len(name, hidden_new_dentry->d_parent, | ||
3704 | + new_dentry->d_name.len + UNIONFS_WHLEN); | ||
3705 | + if (IS_ERR(whiteout_dentry)) { | ||
3706 | + err = PTR_ERR(whiteout_dentry); | ||
3707 | + goto out; | ||
3708 | + } | ||
3709 | + | ||
3710 | + if (!whiteout_dentry->d_inode) { | ||
3711 | + dput(whiteout_dentry); | ||
3712 | + whiteout_dentry = NULL; | ||
3713 | + } else { | ||
3714 | + /* found a .wh.foo entry, unlink it and then call vfs_link() */ | ||
3715 | + hidden_dir_dentry = lock_parent(whiteout_dentry); | ||
3716 | + err = is_robranch_super(new_dentry->d_sb, dbstart(new_dentry)); | ||
3717 | + if (!err) | ||
3718 | + err = vfs_unlink(hidden_dir_dentry->d_inode, | ||
3719 | + whiteout_dentry); | ||
3720 | + | ||
3721 | + fsstack_copy_attr_times(dir, hidden_dir_dentry->d_inode); | ||
3722 | + dir->i_nlink = unionfs_get_nlinks(dir); | ||
3723 | + unlock_dir(hidden_dir_dentry); | ||
3724 | + hidden_dir_dentry = NULL; | ||
3725 | + dput(whiteout_dentry); | ||
3726 | + if (err) | ||
3727 | + goto out; | ||
3728 | + } | ||
3729 | + | ||
3730 | + if (dbstart(old_dentry) != dbstart(new_dentry)) { | ||
3731 | + hidden_new_dentry = | ||
3732 | + create_parents(dir, new_dentry, dbstart(old_dentry)); | ||
3733 | + err = PTR_ERR(hidden_new_dentry); | ||
3734 | + if (IS_COPYUP_ERR(err)) | ||
3735 | + goto docopyup; | ||
3736 | + if (!hidden_new_dentry || IS_ERR(hidden_new_dentry)) | ||
3737 | + goto out; | ||
3738 | + } | ||
3739 | + hidden_new_dentry = unionfs_lower_dentry(new_dentry); | ||
3740 | + hidden_old_dentry = unionfs_lower_dentry(old_dentry); | ||
3741 | + | ||
3742 | + BUG_ON(dbstart(old_dentry) != dbstart(new_dentry)); | ||
3743 | + hidden_dir_dentry = lock_parent(hidden_new_dentry); | ||
3744 | + if (!(err = is_robranch(old_dentry))) | ||
3745 | + err = vfs_link(hidden_old_dentry, hidden_dir_dentry->d_inode, | ||
3746 | + hidden_new_dentry); | ||
3747 | + unlock_dir(hidden_dir_dentry); | ||
3748 | + | ||
3749 | +docopyup: | ||
3750 | + if (IS_COPYUP_ERR(err)) { | ||
3751 | + int old_bstart = dbstart(old_dentry); | ||
3752 | + int bindex; | ||
3753 | + | ||
3754 | + for (bindex = old_bstart - 1; bindex >= 0; bindex--) { | ||
3755 | + err = | ||
3756 | + copyup_dentry(old_dentry->d_parent-> | ||
3757 | + d_inode, old_dentry, | ||
3758 | + old_bstart, bindex, NULL, | ||
3759 | + old_dentry->d_inode->i_size); | ||
3760 | + if (!err) { | ||
3761 | + hidden_new_dentry = | ||
3762 | + create_parents(dir, new_dentry, bindex); | ||
3763 | + hidden_old_dentry = unionfs_lower_dentry(old_dentry); | ||
3764 | + hidden_dir_dentry = | ||
3765 | + lock_parent(hidden_new_dentry); | ||
3766 | + /* do vfs_link */ | ||
3767 | + err = vfs_link(hidden_old_dentry, | ||
3768 | + hidden_dir_dentry->d_inode, | ||
3769 | + hidden_new_dentry); | ||
3770 | + unlock_dir(hidden_dir_dentry); | ||
3771 | + goto check_link; | ||
3772 | + } | ||
3773 | + } | ||
3774 | + goto out; | ||
3775 | + } | ||
3776 | + | ||
3777 | +check_link: | ||
3778 | + if (err || !hidden_new_dentry->d_inode) | ||
3779 | + goto out; | ||
3780 | + | ||
3781 | + /* Its a hard link, so use the same inode */ | ||
3782 | + new_dentry->d_inode = igrab(old_dentry->d_inode); | ||
3783 | + d_instantiate(new_dentry, new_dentry->d_inode); | ||
3784 | + fsstack_copy_attr_all(dir, hidden_new_dentry->d_parent->d_inode, | ||
3785 | + unionfs_get_nlinks); | ||
3786 | + fsstack_copy_inode_size(dir, hidden_new_dentry->d_parent->d_inode); | ||
3787 | + | ||
3788 | + /* propagate number of hard-links */ | ||
3789 | + old_dentry->d_inode->i_nlink = unionfs_get_nlinks(old_dentry->d_inode); | ||
3790 | + | ||
3791 | +out: | ||
3792 | + if (!new_dentry->d_inode) | ||
3793 | + d_drop(new_dentry); | ||
3794 | + | ||
3795 | + kfree(name); | ||
3796 | + | ||
3797 | + unionfs_unlock_dentry(new_dentry); | ||
3798 | + unionfs_unlock_dentry(old_dentry); | ||
3799 | + | ||
3800 | + return err; | ||
3801 | +} | ||
3802 | + | ||
3803 | +static int unionfs_symlink(struct inode *dir, struct dentry *dentry, | ||
3804 | + const char *symname) | ||
3805 | +{ | ||
3806 | + int err = 0; | ||
3807 | + struct dentry *hidden_dentry = NULL; | ||
3808 | + struct dentry *whiteout_dentry = NULL; | ||
3809 | + struct dentry *hidden_dir_dentry = NULL; | ||
3810 | + umode_t mode; | ||
3811 | + int bindex = 0, bstart; | ||
3812 | + char *name = NULL; | ||
3813 | + | ||
3814 | + BUG_ON(!is_valid_dentry(dentry)); | ||
3815 | + | ||
3816 | + unionfs_lock_dentry(dentry); | ||
3817 | + | ||
3818 | + /* We start out in the leftmost branch. */ | ||
3819 | + bstart = dbstart(dentry); | ||
3820 | + | ||
3821 | + hidden_dentry = unionfs_lower_dentry(dentry); | ||
3822 | + | ||
3823 | + /* check if whiteout exists in this branch, i.e. lookup .wh.foo | ||
3824 | + * first. If present, delete it | ||
3825 | + */ | ||
3826 | + name = alloc_whname(dentry->d_name.name, dentry->d_name.len); | ||
3827 | + if (IS_ERR(name)) { | ||
3828 | + err = PTR_ERR(name); | ||
3829 | + goto out; | ||
3830 | + } | ||
3831 | + | ||
3832 | + whiteout_dentry = | ||
3833 | + lookup_one_len(name, hidden_dentry->d_parent, | ||
3834 | + dentry->d_name.len + UNIONFS_WHLEN); | ||
3835 | + if (IS_ERR(whiteout_dentry)) { | ||
3836 | + err = PTR_ERR(whiteout_dentry); | ||
3837 | + goto out; | ||
3838 | + } | ||
3839 | + | ||
3840 | + if (!whiteout_dentry->d_inode) { | ||
3841 | + dput(whiteout_dentry); | ||
3842 | + whiteout_dentry = NULL; | ||
3843 | + } else { | ||
3844 | + /* found a .wh.foo entry, unlink it and then call vfs_symlink() */ | ||
3845 | + hidden_dir_dentry = lock_parent(whiteout_dentry); | ||
3846 | + | ||
3847 | + if (!(err = is_robranch_super(dentry->d_sb, bstart))) | ||
3848 | + err = vfs_unlink(hidden_dir_dentry->d_inode, | ||
3849 | + whiteout_dentry); | ||
3850 | + dput(whiteout_dentry); | ||
3851 | + | ||
3852 | + fsstack_copy_attr_times(dir, hidden_dir_dentry->d_inode); | ||
3853 | + /* propagate number of hard-links */ | ||
3854 | + dir->i_nlink = unionfs_get_nlinks(dir); | ||
3855 | + | ||
3856 | + unlock_dir(hidden_dir_dentry); | ||
3857 | + | ||
3858 | + if (err) { | ||
3859 | + /* exit if the error returned was NOT -EROFS */ | ||
3860 | + if (!IS_COPYUP_ERR(err)) | ||
3861 | + goto out; | ||
3862 | + /* should now try to create symlink in the another branch */ | ||
3863 | + bstart--; | ||
3864 | + } | ||
3865 | + } | ||
3866 | + | ||
3867 | + /* deleted whiteout if it was present, now do a normal vfs_symlink() | ||
3868 | + * with possible recursive directory creation | ||
3869 | + */ | ||
3870 | + for (bindex = bstart; bindex >= 0; bindex--) { | ||
3871 | + hidden_dentry = unionfs_lower_dentry_idx(dentry, bindex); | ||
3872 | + if (!hidden_dentry) { | ||
3873 | + /* if hidden_dentry is NULL, create the entire | ||
3874 | + * dentry directory structure in branch 'bindex'. | ||
3875 | + * hidden_dentry will NOT be null when bindex == | ||
3876 | + * bstart because lookup passed as a negative | ||
3877 | + * unionfs dentry pointing to a lone negative | ||
3878 | + * underlying dentry | ||
3879 | + */ | ||
3880 | + hidden_dentry = create_parents(dir, dentry, bindex); | ||
3881 | + if (!hidden_dentry || IS_ERR(hidden_dentry)) { | ||
3882 | + if (IS_ERR(hidden_dentry)) | ||
3883 | + err = PTR_ERR(hidden_dentry); | ||
3884 | + | ||
3885 | + printk(KERN_DEBUG "hidden dentry NULL (or error)" | ||
3886 | + "for bindex = %d\n", bindex); | ||
3887 | + continue; | ||
3888 | + } | ||
3889 | + } | ||
3890 | + | ||
3891 | + hidden_dir_dentry = lock_parent(hidden_dentry); | ||
3892 | + | ||
3893 | + if (!(err = is_robranch_super(dentry->d_sb, bindex))) { | ||
3894 | + mode = S_IALLUGO; | ||
3895 | + err = | ||
3896 | + vfs_symlink(hidden_dir_dentry->d_inode, | ||
3897 | + hidden_dentry, symname, mode); | ||
3898 | + } | ||
3899 | + unlock_dir(hidden_dir_dentry); | ||
3900 | + | ||
3901 | + if (err || !hidden_dentry->d_inode) { | ||
3902 | + /* break out of for loop if error returned was NOT -EROFS */ | ||
3903 | + if (!IS_COPYUP_ERR(err)) | ||
3904 | + break; | ||
3905 | + } else { | ||
3906 | + err = unionfs_interpose(dentry, dir->i_sb, 0); | ||
3907 | + if (!err) { | ||
3908 | + fsstack_copy_attr_times(dir, | ||
3909 | + hidden_dir_dentry->d_inode); | ||
3910 | + fsstack_copy_inode_size(dir, | ||
3911 | + hidden_dir_dentry->d_inode); | ||
3912 | + /* update number of links on parent directory */ | ||
3913 | + dir->i_nlink = unionfs_get_nlinks(dir); | ||
3914 | + } | ||
3915 | + break; | ||
3916 | + } | ||
3917 | + } | ||
3918 | + | ||
3919 | +out: | ||
3920 | + if (!dentry->d_inode) | ||
3921 | + d_drop(dentry); | ||
3922 | + | ||
3923 | + kfree(name); | ||
3924 | + unionfs_unlock_dentry(dentry); | ||
3925 | + return err; | ||
3926 | +} | ||
3927 | + | ||
3928 | +static int unionfs_mkdir(struct inode *parent, struct dentry *dentry, int mode) | ||
3929 | +{ | ||
3930 | + int err = 0; | ||
3931 | + struct dentry *hidden_dentry = NULL, *whiteout_dentry = NULL; | ||
3932 | + struct dentry *hidden_parent_dentry = NULL; | ||
3933 | + int bindex = 0, bstart; | ||
3934 | + char *name = NULL; | ||
3935 | + int whiteout_unlinked = 0; | ||
3936 | + struct sioq_args args; | ||
3937 | + | ||
3938 | + BUG_ON(!is_valid_dentry(dentry)); | ||
3939 | + | ||
3940 | + unionfs_lock_dentry(dentry); | ||
3941 | + bstart = dbstart(dentry); | ||
3942 | + | ||
3943 | + hidden_dentry = unionfs_lower_dentry(dentry); | ||
3944 | + | ||
3945 | + /* check if whiteout exists in this branch, i.e. lookup .wh.foo first */ | ||
3946 | + name = alloc_whname(dentry->d_name.name, dentry->d_name.len); | ||
3947 | + if (IS_ERR(name)) { | ||
3948 | + err = PTR_ERR(name); | ||
3949 | + goto out; | ||
3950 | + } | ||
3951 | + | ||
3952 | + whiteout_dentry = lookup_one_len(name, hidden_dentry->d_parent, | ||
3953 | + dentry->d_name.len + UNIONFS_WHLEN); | ||
3954 | + if (IS_ERR(whiteout_dentry)) { | ||
3955 | + err = PTR_ERR(whiteout_dentry); | ||
3956 | + goto out; | ||
3957 | + } | ||
3958 | + | ||
3959 | + if (!whiteout_dentry->d_inode) { | ||
3960 | + dput(whiteout_dentry); | ||
3961 | + whiteout_dentry = NULL; | ||
3962 | + } else { | ||
3963 | + hidden_parent_dentry = lock_parent(whiteout_dentry); | ||
3964 | + | ||
3965 | + /* found a.wh.foo entry, remove it then do vfs_mkdir */ | ||
3966 | + if (!(err = is_robranch_super(dentry->d_sb, bstart))) { | ||
3967 | + args.unlink.parent = hidden_parent_dentry->d_inode; | ||
3968 | + args.unlink.dentry = whiteout_dentry; | ||
3969 | + run_sioq(__unionfs_unlink, &args); | ||
3970 | + err = args.err; | ||
3971 | + } | ||
3972 | + dput(whiteout_dentry); | ||
3973 | + | ||
3974 | + unlock_dir(hidden_parent_dentry); | ||
3975 | + | ||
3976 | + if (err) { | ||
3977 | + /* exit if the error returned was NOT -EROFS */ | ||
3978 | + if (!IS_COPYUP_ERR(err)) | ||
3979 | + goto out; | ||
3980 | + bstart--; | ||
3981 | + } else | ||
3982 | + whiteout_unlinked = 1; | ||
3983 | + } | ||
3984 | + | ||
3985 | + for (bindex = bstart; bindex >= 0; bindex--) { | ||
3986 | + int i; | ||
3987 | + int bend = dbend(dentry); | ||
3988 | + | ||
3989 | + if (is_robranch_super(dentry->d_sb, bindex)) | ||
3990 | + continue; | ||
3991 | + | ||
3992 | + hidden_dentry = unionfs_lower_dentry_idx(dentry, bindex); | ||
3993 | + if (!hidden_dentry) { | ||
3994 | + hidden_dentry = create_parents(parent, dentry, bindex); | ||
3995 | + if (!hidden_dentry || IS_ERR(hidden_dentry)) { | ||
3996 | + printk(KERN_DEBUG "hidden dentry NULL for " | ||
3997 | + "bindex = %d\n", bindex); | ||
3998 | + continue; | ||
3999 | + } | ||
4000 | + } | ||
4001 | + | ||
4002 | + hidden_parent_dentry = lock_parent(hidden_dentry); | ||
4003 | + | ||
4004 | + if (IS_ERR(hidden_parent_dentry)) { | ||
4005 | + err = PTR_ERR(hidden_parent_dentry); | ||
4006 | + goto out; | ||
4007 | + } | ||
4008 | + | ||
4009 | + err = vfs_mkdir(hidden_parent_dentry->d_inode, hidden_dentry, mode); | ||
4010 | + | ||
4011 | + unlock_dir(hidden_parent_dentry); | ||
4012 | + | ||
4013 | + /* did the mkdir suceed? */ | ||
4014 | + if (err) | ||
4015 | + break; | ||
4016 | + | ||
4017 | + for (i = bindex + 1; i < bend; i++) { | ||
4018 | + if (unionfs_lower_dentry_idx(dentry, i)) { | ||
4019 | + dput(unionfs_lower_dentry_idx(dentry, i)); | ||
4020 | + unionfs_set_lower_dentry_idx(dentry, i, NULL); | ||
4021 | + } | ||
4022 | + } | ||
4023 | + set_dbend(dentry, bindex); | ||
4024 | + | ||
4025 | + err = unionfs_interpose(dentry, parent->i_sb, 0); | ||
4026 | + if (!err) { | ||
4027 | + fsstack_copy_attr_times(parent, | ||
4028 | + hidden_parent_dentry->d_inode); | ||
4029 | + fsstack_copy_inode_size(parent, | ||
4030 | + hidden_parent_dentry->d_inode); | ||
4031 | + | ||
4032 | + /* update number of links on parent directory */ | ||
4033 | + parent->i_nlink = unionfs_get_nlinks(parent); | ||
4034 | + } | ||
4035 | + | ||
4036 | + err = make_dir_opaque(dentry, dbstart(dentry)); | ||
4037 | + if (err) { | ||
4038 | + printk(KERN_ERR "mkdir: error creating " | ||
4039 | + ".wh.__dir_opaque: %d\n", err); | ||
4040 | + goto out; | ||
4041 | + } | ||
4042 | + | ||
4043 | + /* we are done! */ | ||
4044 | + break; | ||
4045 | + } | ||
4046 | + | ||
4047 | +out: | ||
4048 | + if (!dentry->d_inode) | ||
4049 | + d_drop(dentry); | ||
4050 | + | ||
4051 | + kfree(name); | ||
4052 | + | ||
4053 | + unionfs_unlock_dentry(dentry); | ||
4054 | + return err; | ||
4055 | +} | ||
4056 | + | ||
4057 | +static int unionfs_mknod(struct inode *dir, struct dentry *dentry, int mode, | ||
4058 | + dev_t dev) | ||
4059 | +{ | ||
4060 | + int err = 0; | ||
4061 | + struct dentry *hidden_dentry = NULL, *whiteout_dentry = NULL; | ||
4062 | + struct dentry *hidden_parent_dentry = NULL; | ||
4063 | + int bindex = 0, bstart; | ||
4064 | + char *name = NULL; | ||
4065 | + int whiteout_unlinked = 0; | ||
4066 | + | ||
4067 | + BUG_ON(!is_valid_dentry(dentry)); | ||
4068 | + | ||
4069 | + unionfs_lock_dentry(dentry); | ||
4070 | + bstart = dbstart(dentry); | ||
4071 | + | ||
4072 | + hidden_dentry = unionfs_lower_dentry(dentry); | ||
4073 | + | ||
4074 | + /* check if whiteout exists in this branch, i.e. lookup .wh.foo first */ | ||
4075 | + name = alloc_whname(dentry->d_name.name, dentry->d_name.len); | ||
4076 | + if (IS_ERR(name)) { | ||
4077 | + err = PTR_ERR(name); | ||
4078 | + goto out; | ||
4079 | + } | ||
4080 | + | ||
4081 | + whiteout_dentry = lookup_one_len(name, hidden_dentry->d_parent, | ||
4082 | + dentry->d_name.len + UNIONFS_WHLEN); | ||
4083 | + if (IS_ERR(whiteout_dentry)) { | ||
4084 | + err = PTR_ERR(whiteout_dentry); | ||
4085 | + goto out; | ||
4086 | + } | ||
4087 | + | ||
4088 | + if (!whiteout_dentry->d_inode) { | ||
4089 | + dput(whiteout_dentry); | ||
4090 | + whiteout_dentry = NULL; | ||
4091 | + } else { | ||
4092 | + /* found .wh.foo, unlink it */ | ||
4093 | + hidden_parent_dentry = lock_parent(whiteout_dentry); | ||
4094 | + | ||
4095 | + /* found a.wh.foo entry, remove it then do vfs_mkdir */ | ||
4096 | + if (!(err = is_robranch_super(dentry->d_sb, bstart))) | ||
4097 | + err = vfs_unlink(hidden_parent_dentry->d_inode, | ||
4098 | + whiteout_dentry); | ||
4099 | + dput(whiteout_dentry); | ||
4100 | + | ||
4101 | + unlock_dir(hidden_parent_dentry); | ||
4102 | + | ||
4103 | + if (err) { | ||
4104 | + if (!IS_COPYUP_ERR(err)) | ||
4105 | + goto out; | ||
4106 | + | ||
4107 | + bstart--; | ||
4108 | + } else | ||
4109 | + whiteout_unlinked = 1; | ||
4110 | + } | ||
4111 | + | ||
4112 | + for (bindex = bstart; bindex >= 0; bindex--) { | ||
4113 | + if (is_robranch_super(dentry->d_sb, bindex)) | ||
4114 | + continue; | ||
4115 | + | ||
4116 | + hidden_dentry = unionfs_lower_dentry_idx(dentry, bindex); | ||
4117 | + if (!hidden_dentry) { | ||
4118 | + hidden_dentry = create_parents(dir, dentry, bindex); | ||
4119 | + if (IS_ERR(hidden_dentry)) { | ||
4120 | + printk(KERN_DEBUG | ||
4121 | + "failed to create parents on %d, err = %ld\n", | ||
4122 | + bindex, PTR_ERR(hidden_dentry)); | ||
4123 | + continue; | ||
4124 | + } | ||
4125 | + } | ||
4126 | + | ||
4127 | + hidden_parent_dentry = lock_parent(hidden_dentry); | ||
4128 | + if (IS_ERR(hidden_parent_dentry)) { | ||
4129 | + err = PTR_ERR(hidden_parent_dentry); | ||
4130 | + goto out; | ||
4131 | + } | ||
4132 | + | ||
4133 | + err = vfs_mknod(hidden_parent_dentry->d_inode, | ||
4134 | + hidden_dentry, mode, dev); | ||
4135 | + | ||
4136 | + if (err) { | ||
4137 | + unlock_dir(hidden_parent_dentry); | ||
4138 | + break; | ||
4139 | + } | ||
4140 | + | ||
4141 | + err = unionfs_interpose(dentry, dir->i_sb, 0); | ||
4142 | + if (!err) { | ||
4143 | + fsstack_copy_attr_times(dir, | ||
4144 | + hidden_parent_dentry->d_inode); | ||
4145 | + fsstack_copy_inode_size(dir, | ||
4146 | + hidden_parent_dentry->d_inode); | ||
4147 | + /* update number of links on parent directory */ | ||
4148 | + dir->i_nlink = unionfs_get_nlinks(dir); | ||
4149 | + } | ||
4150 | + unlock_dir(hidden_parent_dentry); | ||
4151 | + | ||
4152 | + break; | ||
4153 | + } | ||
4154 | + | ||
4155 | +out: | ||
4156 | + if (!dentry->d_inode) | ||
4157 | + d_drop(dentry); | ||
4158 | + | ||
4159 | + kfree(name); | ||
4160 | + | ||
4161 | + unionfs_unlock_dentry(dentry); | ||
4162 | + return err; | ||
4163 | +} | ||
4164 | + | ||
4165 | +static int unionfs_readlink(struct dentry *dentry, char __user * buf, | ||
4166 | + int bufsiz) | ||
4167 | +{ | ||
4168 | + int err; | ||
4169 | + struct dentry *hidden_dentry; | ||
4170 | + | ||
4171 | + BUG_ON(!is_valid_dentry(dentry)); | ||
4172 | + | ||
4173 | + unionfs_lock_dentry(dentry); | ||
4174 | + hidden_dentry = unionfs_lower_dentry(dentry); | ||
4175 | + | ||
4176 | + if (!hidden_dentry->d_inode->i_op || | ||
4177 | + !hidden_dentry->d_inode->i_op->readlink) { | ||
4178 | + err = -EINVAL; | ||
4179 | + goto out; | ||
4180 | + } | ||
4181 | + | ||
4182 | + err = hidden_dentry->d_inode->i_op->readlink(hidden_dentry, buf, bufsiz); | ||
4183 | + if (err > 0) | ||
4184 | + fsstack_copy_attr_atime(dentry->d_inode, hidden_dentry->d_inode); | ||
4185 | + | ||
4186 | +out: | ||
4187 | + unionfs_unlock_dentry(dentry); | ||
4188 | + return err; | ||
4189 | +} | ||
4190 | + | ||
4191 | +/* We don't lock the dentry here, because readlink does the heavy lifting. */ | ||
4192 | +static void *unionfs_follow_link(struct dentry *dentry, struct nameidata *nd) | ||
4193 | +{ | ||
4194 | + char *buf; | ||
4195 | + int len = PAGE_SIZE, err; | ||
4196 | + mm_segment_t old_fs; | ||
4197 | + | ||
4198 | + BUG_ON(!is_valid_dentry(dentry)); | ||
4199 | + | ||
4200 | + /* This is freed by the put_link method assuming a successful call. */ | ||
4201 | + buf = kmalloc(len, GFP_KERNEL); | ||
4202 | + if (!buf) { | ||
4203 | + err = -ENOMEM; | ||
4204 | + goto out; | ||
4205 | + } | ||
4206 | + | ||
4207 | + /* read the symlink, and then we will follow it */ | ||
4208 | + old_fs = get_fs(); | ||
4209 | + set_fs(KERNEL_DS); | ||
4210 | + err = dentry->d_inode->i_op->readlink(dentry, (char __user *)buf, len); | ||
4211 | + set_fs(old_fs); | ||
4212 | + if (err < 0) { | ||
4213 | + kfree(buf); | ||
4214 | + buf = NULL; | ||
4215 | + goto out; | ||
4216 | + } | ||
4217 | + buf[err] = 0; | ||
4218 | + nd_set_link(nd, buf); | ||
4219 | + err = 0; | ||
4220 | + | ||
4221 | +out: | ||
4222 | + return ERR_PTR(err); | ||
4223 | +} | ||
4224 | + | ||
4225 | +static void unionfs_put_link(struct dentry *dentry, struct nameidata *nd, | ||
4226 | + void *cookie) | ||
4227 | +{ | ||
4228 | + kfree(nd_get_link(nd)); | ||
4229 | +} | ||
4230 | + | ||
4231 | +/* Basically copied from the kernel vfs permission(), but we've changed | ||
4232 | + * the following: | ||
4233 | + * (1) the IS_RDONLY check is skipped, and | ||
4234 | + * (2) if you set the mount option `mode=nfsro', we assume that -EACCES | ||
4235 | + * means that the export is read-only and we should check standard Unix | ||
4236 | + * permissions. This means that NFS ACL checks (or other advanced | ||
4237 | + * permission features) are bypassed. Note however, that we do call | ||
4238 | + * security_inode_permission, and therefore security inside SELinux, etc. | ||
4239 | + * are performed. | ||
4240 | + */ | ||
4241 | +static int inode_permission(struct inode *inode, int mask, struct nameidata *nd, | ||
4242 | + int bindex) | ||
4243 | +{ | ||
4244 | + int retval, submask; | ||
4245 | + | ||
4246 | + if (mask & MAY_WRITE) { | ||
4247 | + /* The first branch is allowed to be really readonly. */ | ||
4248 | + if (bindex == 0) { | ||
4249 | + umode_t mode = inode->i_mode; | ||
4250 | + if (IS_RDONLY(inode) && | ||
4251 | + (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) | ||
4252 | + return -EROFS; | ||
4253 | + } | ||
4254 | + /* | ||
4255 | + * Nobody gets write access to an immutable file. | ||
4256 | + */ | ||
4257 | + if (IS_IMMUTABLE(inode)) | ||
4258 | + return -EACCES; | ||
4259 | + } | ||
4260 | + | ||
4261 | + /* Ordinary permission routines do not understand MAY_APPEND. */ | ||
4262 | + submask = mask & ~MAY_APPEND; | ||
4263 | + if (inode->i_op && inode->i_op->permission) { | ||
4264 | + retval = inode->i_op->permission(inode, submask, nd); | ||
4265 | + if ((retval == -EACCES) && (submask & MAY_WRITE) && | ||
4266 | + (!strcmp("nfs", (inode)->i_sb->s_type->name)) && | ||
4267 | + (nd) && (nd->mnt) && (nd->mnt->mnt_sb)) { | ||
4268 | + int perms; | ||
4269 | + unionfs_read_lock(nd->mnt->mnt_sb); | ||
4270 | + perms = branchperms(nd->mnt->mnt_sb, bindex); | ||
4271 | + unionfs_read_unlock(nd->mnt->mnt_sb); | ||
4272 | + if (perms & MAY_NFSRO) | ||
4273 | + retval = generic_permission(inode, submask, NULL); | ||
4274 | + } | ||
4275 | + } else | ||
4276 | + retval = generic_permission(inode, submask, NULL); | ||
4277 | + | ||
4278 | + if (retval && retval != -EROFS) /* ignore EROFS */ | ||
4279 | + return retval; | ||
4280 | + | ||
4281 | + retval = security_inode_permission(inode, mask, nd); | ||
4282 | + return ((retval == -EROFS) ? 0 : retval); /* ignore EROFS */ | ||
4283 | +} | ||
4284 | + | ||
4285 | +static int unionfs_permission(struct inode *inode, int mask, | ||
4286 | + struct nameidata *nd) | ||
4287 | +{ | ||
4288 | + struct inode *hidden_inode = NULL; | ||
4289 | + int err = 0; | ||
4290 | + int bindex, bstart, bend; | ||
4291 | + const int is_file = !S_ISDIR(inode->i_mode); | ||
4292 | + const int write_mask = (mask & MAY_WRITE) && !(mask & MAY_READ); | ||
4293 | + | ||
4294 | + unionfs_read_lock(inode->i_sb); | ||
4295 | + | ||
4296 | + bstart = ibstart(inode); | ||
4297 | + bend = ibend(inode); | ||
4298 | + if (bstart < 0 || bend < 0) { | ||
4299 | + /* | ||
4300 | + * With branch-management, we can get a stale inode here. | ||
4301 | + * If so, we return ESTALE back to link_path_walk, which | ||
4302 | + * would discard the dcache entry and re-lookup the | ||
4303 | + * dentry+inode. This should be equivalent to issuing | ||
4304 | + * __unionfs_d_revalidate_chain on nd.dentry here. | ||
4305 | + */ | ||
4306 | + err = -ESTALE; /* force revalidate */ | ||
4307 | + goto out; | ||
4308 | + } | ||
4309 | + | ||
4310 | + for (bindex = bstart; bindex <= bend; bindex++) { | ||
4311 | + hidden_inode = unionfs_lower_inode_idx(inode, bindex); | ||
4312 | + if (!hidden_inode) | ||
4313 | + continue; | ||
4314 | + | ||
4315 | + /* check the condition for D-F-D underlying files/directories, | ||
4316 | + * we dont have to check for files, if we are checking for | ||
4317 | + * directories. | ||
4318 | + */ | ||
4319 | + if (!is_file && !S_ISDIR(hidden_inode->i_mode)) | ||
4320 | + continue; | ||
4321 | + | ||
4322 | + /* We use our own special version of permission, such that | ||
4323 | + * only the first branch returns -EROFS. | ||
4324 | + */ | ||
4325 | + err = inode_permission(hidden_inode, mask, nd, bindex); | ||
4326 | + | ||
4327 | + /* The permissions are an intersection of the overall directory | ||
4328 | + * permissions, so we fail if one fails. | ||
4329 | + */ | ||
4330 | + if (err) | ||
4331 | + goto out; | ||
4332 | + | ||
4333 | + /* only the leftmost file matters. */ | ||
4334 | + if (is_file || write_mask) { | ||
4335 | + if (is_file && write_mask) { | ||
4336 | + err = get_write_access(hidden_inode); | ||
4337 | + if (!err) | ||
4338 | + put_write_access(hidden_inode); | ||
4339 | + } | ||
4340 | + break; | ||
4341 | + } | ||
4342 | + } | ||
4343 | + | ||
4344 | +out: | ||
4345 | + unionfs_read_unlock(inode->i_sb); | ||
4346 | + return err; | ||
4347 | +} | ||
4348 | + | ||
4349 | +static int unionfs_setattr(struct dentry *dentry, struct iattr *ia) | ||
4350 | +{ | ||
4351 | + int err = 0; | ||
4352 | + struct dentry *hidden_dentry; | ||
4353 | + struct inode *inode = NULL; | ||
4354 | + struct inode *hidden_inode = NULL; | ||
4355 | + int bstart, bend, bindex; | ||
4356 | + int i; | ||
4357 | + int copyup = 0; | ||
4358 | + | ||
4359 | + BUG_ON(!is_valid_dentry(dentry)); | ||
4360 | + | ||
4361 | + unionfs_lock_dentry(dentry); | ||
4362 | + bstart = dbstart(dentry); | ||
4363 | + bend = dbend(dentry); | ||
4364 | + inode = dentry->d_inode; | ||
4365 | + | ||
4366 | + for (bindex = bstart; (bindex <= bend) || (bindex == bstart); bindex++) { | ||
4367 | + hidden_dentry = unionfs_lower_dentry_idx(dentry, bindex); | ||
4368 | + if (!hidden_dentry) | ||
4369 | + continue; | ||
4370 | + BUG_ON(hidden_dentry->d_inode == NULL); | ||
4371 | + | ||
4372 | + /* If the file is on a read only branch */ | ||
4373 | + if (is_robranch_super(dentry->d_sb, bindex) | ||
4374 | + || IS_RDONLY(hidden_dentry->d_inode)) { | ||
4375 | + if (copyup || (bindex != bstart)) | ||
4376 | + continue; | ||
4377 | + /* Only if its the leftmost file, copyup the file */ | ||
4378 | + for (i = bstart - 1; i >= 0; i--) { | ||
4379 | + loff_t size = dentry->d_inode->i_size; | ||
4380 | + if (ia->ia_valid & ATTR_SIZE) | ||
4381 | + size = ia->ia_size; | ||
4382 | + err = copyup_dentry(dentry->d_parent->d_inode, | ||
4383 | + dentry, bstart, i, NULL, | ||
4384 | + size); | ||
4385 | + | ||
4386 | + if (!err) { | ||
4387 | + copyup = 1; | ||
4388 | + hidden_dentry = unionfs_lower_dentry(dentry); | ||
4389 | + break; | ||
4390 | + } | ||
4391 | + /* if error is in the leftmost branch, pass it up */ | ||
4392 | + if (i == 0) | ||
4393 | + goto out; | ||
4394 | + } | ||
4395 | + | ||
4396 | + } | ||
4397 | + err = notify_change(hidden_dentry, ia); | ||
4398 | + if (err) | ||
4399 | + goto out; | ||
4400 | + break; | ||
4401 | + } | ||
4402 | + | ||
4403 | + /* get the size from the first hidden inode */ | ||
4404 | + hidden_inode = unionfs_lower_inode(dentry->d_inode); | ||
4405 | + fsstack_copy_attr_all(inode, hidden_inode, unionfs_get_nlinks); | ||
4406 | + fsstack_copy_inode_size(inode, hidden_inode); | ||
4407 | + | ||
4408 | +out: | ||
4409 | + unionfs_unlock_dentry(dentry); | ||
4410 | + return err; | ||
4411 | +} | ||
4412 | + | ||
4413 | +struct inode_operations unionfs_symlink_iops = { | ||
4414 | + .readlink = unionfs_readlink, | ||
4415 | + .permission = unionfs_permission, | ||
4416 | + .follow_link = unionfs_follow_link, | ||
4417 | + .setattr = unionfs_setattr, | ||
4418 | + .put_link = unionfs_put_link, | ||
4419 | +}; | ||
4420 | + | ||
4421 | +struct inode_operations unionfs_dir_iops = { | ||
4422 | + .create = unionfs_create, | ||
4423 | + .lookup = unionfs_lookup, | ||
4424 | + .link = unionfs_link, | ||
4425 | + .unlink = unionfs_unlink, | ||
4426 | + .symlink = unionfs_symlink, | ||
4427 | + .mkdir = unionfs_mkdir, | ||
4428 | + .rmdir = unionfs_rmdir, | ||
4429 | + .mknod = unionfs_mknod, | ||
4430 | + .rename = unionfs_rename, | ||
4431 | + .permission = unionfs_permission, | ||
4432 | + .setattr = unionfs_setattr, | ||
4433 | +#ifdef CONFIG_UNION_FS_XATTR | ||
4434 | + .setxattr = unionfs_setxattr, | ||
4435 | + .getxattr = unionfs_getxattr, | ||
4436 | + .removexattr = unionfs_removexattr, | ||
4437 | + .listxattr = unionfs_listxattr, | ||
4438 | +#endif | ||
4439 | +}; | ||
4440 | + | ||
4441 | +struct inode_operations unionfs_main_iops = { | ||
4442 | + .permission = unionfs_permission, | ||
4443 | + .setattr = unionfs_setattr, | ||
4444 | +#ifdef CONFIG_UNION_FS_XATTR | ||
4445 | + .setxattr = unionfs_setxattr, | ||
4446 | + .getxattr = unionfs_getxattr, | ||
4447 | + .removexattr = unionfs_removexattr, | ||
4448 | + .listxattr = unionfs_listxattr, | ||
4449 | +#endif | ||
4450 | +}; | ||
4451 | + | ||
4452 | diff --git a/fs/unionfs/lookup.c b/fs/unionfs/lookup.c | ||
4453 | new file mode 100644 | ||
4454 | index 0000000..0fc5993 | ||
4455 | --- /dev/null | ||
4456 | +++ b/fs/unionfs/lookup.c | ||
4457 | @@ -0,0 +1,523 @@ | ||
4458 | +/* | ||
4459 | + * Copyright (c) 2003-2007 Erez Zadok | ||
4460 | + * Copyright (c) 2003-2006 Charles P. Wright | ||
4461 | + * Copyright (c) 2005-2007 Josef 'Jeff' Sipek | ||
4462 | + * Copyright (c) 2005-2006 Junjiro Okajima | ||
4463 | + * Copyright (c) 2005 Arun M. Krishnakumar | ||
4464 | + * Copyright (c) 2004-2006 David P. Quigley | ||
4465 | + * Copyright (c) 2003-2004 Mohammad Nayyer Zubair | ||
4466 | + * Copyright (c) 2003 Puja Gupta | ||
4467 | + * Copyright (c) 2003 Harikesavan Krishnan | ||
4468 | + * Copyright (c) 2003-2007 Stony Brook University | ||
4469 | + * Copyright (c) 2003-2007 The Research Foundation of State University of New York | ||
4470 | + * | ||
4471 | + * This program is free software; you can redistribute it and/or modify | ||
4472 | + * it under the terms of the GNU General Public License version 2 as | ||
4473 | + * published by the Free Software Foundation. | ||
4474 | + */ | ||
4475 | + | ||
4476 | +#include "union.h" | ||
4477 | + | ||
4478 | +/* is the filename valid == !(whiteout for a file or opaque dir marker) */ | ||
4479 | +static int is_validname(const char *name) | ||
4480 | +{ | ||
4481 | + if (!strncmp(name, UNIONFS_WHPFX, UNIONFS_WHLEN)) | ||
4482 | + return 0; | ||
4483 | + if (!strncmp(name, UNIONFS_DIR_OPAQUE_NAME, | ||
4484 | + sizeof(UNIONFS_DIR_OPAQUE_NAME) - 1)) | ||
4485 | + return 0; | ||
4486 | + return 1; | ||
4487 | +} | ||
4488 | + | ||
4489 | +/* The rest of these are utility functions for lookup. */ | ||
4490 | +static noinline int is_opaque_dir(struct dentry *dentry, int bindex) | ||
4491 | +{ | ||
4492 | + int err = 0; | ||
4493 | + struct dentry *hidden_dentry; | ||
4494 | + struct dentry *wh_hidden_dentry; | ||
4495 | + struct inode *hidden_inode; | ||
4496 | + struct sioq_args args; | ||
4497 | + | ||
4498 | + hidden_dentry = unionfs_lower_dentry_idx(dentry, bindex); | ||
4499 | + hidden_inode = hidden_dentry->d_inode; | ||
4500 | + | ||
4501 | + BUG_ON(!S_ISDIR(hidden_inode->i_mode)); | ||
4502 | + | ||
4503 | + mutex_lock(&hidden_inode->i_mutex); | ||
4504 | + | ||
4505 | + if (!permission(hidden_inode, MAY_EXEC, NULL)) | ||
4506 | + wh_hidden_dentry = lookup_one_len(UNIONFS_DIR_OPAQUE, hidden_dentry, | ||
4507 | + sizeof(UNIONFS_DIR_OPAQUE) - 1); | ||
4508 | + else { | ||
4509 | + args.is_opaque.dentry = hidden_dentry; | ||
4510 | + run_sioq(__is_opaque_dir, &args); | ||
4511 | + wh_hidden_dentry = args.ret; | ||
4512 | + } | ||
4513 | + | ||
4514 | + mutex_unlock(&hidden_inode->i_mutex); | ||
4515 | + | ||
4516 | + if (IS_ERR(wh_hidden_dentry)) { | ||
4517 | + err = PTR_ERR(wh_hidden_dentry); | ||
4518 | + goto out; | ||
4519 | + } | ||
4520 | + | ||
4521 | + /* This is an opaque dir iff wh_hidden_dentry is positive */ | ||
4522 | + err = !!wh_hidden_dentry->d_inode; | ||
4523 | + | ||
4524 | + dput(wh_hidden_dentry); | ||
4525 | +out: | ||
4526 | + return err; | ||
4527 | +} | ||
4528 | + | ||
4529 | +struct dentry *unionfs_lookup_backend(struct dentry *dentry, struct nameidata *nd, | ||
4530 | + int lookupmode) | ||
4531 | +{ | ||
4532 | + int err = 0; | ||
4533 | + struct dentry *hidden_dentry = NULL; | ||
4534 | + struct dentry *wh_hidden_dentry = NULL; | ||
4535 | + struct dentry *hidden_dir_dentry = NULL; | ||
4536 | + struct dentry *parent_dentry = NULL; | ||
4537 | + int bindex, bstart, bend, bopaque; | ||
4538 | + int dentry_count = 0; /* Number of positive dentries. */ | ||
4539 | + int first_dentry_offset = -1; /* -1 is uninitialized */ | ||
4540 | + struct dentry *first_dentry = NULL; | ||
4541 | + struct dentry *first_hidden_dentry = NULL; | ||
4542 | + struct vfsmount *first_hidden_mnt = NULL; | ||
4543 | + int locked_parent = 0; | ||
4544 | + int locked_child = 0; | ||
4545 | + int allocated_new_info = 0; | ||
4546 | + | ||
4547 | + int opaque; | ||
4548 | + char *whname = NULL; | ||
4549 | + const char *name; | ||
4550 | + int namelen; | ||
4551 | + | ||
4552 | + /* We should already have a lock on this dentry in the case of a | ||
4553 | + * partial lookup, or a revalidation. Otherwise it is returned from | ||
4554 | + * new_dentry_private_data already locked. | ||
4555 | + */ | ||
4556 | + if (lookupmode == INTERPOSE_PARTIAL || lookupmode == INTERPOSE_REVAL || | ||
4557 | + lookupmode == INTERPOSE_REVAL_NEG) | ||
4558 | + verify_locked(dentry); | ||
4559 | + else { | ||
4560 | + BUG_ON(UNIONFS_D(dentry) != NULL); | ||
4561 | + locked_child = 1; | ||
4562 | + } | ||
4563 | + if (lookupmode != INTERPOSE_PARTIAL) { | ||
4564 | + if ((err = new_dentry_private_data(dentry))) | ||
4565 | + goto out; | ||
4566 | + allocated_new_info = 1; | ||
4567 | + } | ||
4568 | + /* must initialize dentry operations */ | ||
4569 | + dentry->d_op = &unionfs_dops; | ||
4570 | + | ||
4571 | + parent_dentry = dget_parent(dentry); | ||
4572 | + /* We never partial lookup the root directory. */ | ||
4573 | + if (parent_dentry != dentry) { | ||
4574 | + unionfs_lock_dentry(parent_dentry); | ||
4575 | + locked_parent = 1; | ||
4576 | + } else { | ||
4577 | + dput(parent_dentry); | ||
4578 | + parent_dentry = NULL; | ||
4579 | + goto out; | ||
4580 | + } | ||
4581 | + | ||
4582 | + name = dentry->d_name.name; | ||
4583 | + namelen = dentry->d_name.len; | ||
4584 | + | ||
4585 | + /* No dentries should get created for possible whiteout names. */ | ||
4586 | + if (!is_validname(name)) { | ||
4587 | + err = -EPERM; | ||
4588 | + goto out_free; | ||
4589 | + } | ||
4590 | + | ||
4591 | + /* Now start the actual lookup procedure. */ | ||
4592 | + bstart = dbstart(parent_dentry); | ||
4593 | + bend = dbend(parent_dentry); | ||
4594 | + bopaque = dbopaque(parent_dentry); | ||
4595 | + BUG_ON(bstart < 0); | ||
4596 | + | ||
4597 | + /* It would be ideal if we could convert partial lookups to only have | ||
4598 | + * to do this work when they really need to. It could probably improve | ||
4599 | + * performance quite a bit, and maybe simplify the rest of the code. | ||
4600 | + */ | ||
4601 | + if (lookupmode == INTERPOSE_PARTIAL) { | ||
4602 | + bstart++; | ||
4603 | + if ((bopaque != -1) && (bopaque < bend)) | ||
4604 | + bend = bopaque; | ||
4605 | + } | ||
4606 | + | ||
4607 | + for (bindex = bstart; bindex <= bend; bindex++) { | ||
4608 | + hidden_dentry = unionfs_lower_dentry_idx(dentry, bindex); | ||
4609 | + if (lookupmode == INTERPOSE_PARTIAL && hidden_dentry) | ||
4610 | + continue; | ||
4611 | + BUG_ON(hidden_dentry != NULL); | ||
4612 | + | ||
4613 | + hidden_dir_dentry = unionfs_lower_dentry_idx(parent_dentry, bindex); | ||
4614 | + | ||
4615 | + /* if the parent hidden dentry does not exist skip this */ | ||
4616 | + if (!(hidden_dir_dentry && hidden_dir_dentry->d_inode)) | ||
4617 | + continue; | ||
4618 | + | ||
4619 | + /* also skip it if the parent isn't a directory. */ | ||
4620 | + if (!S_ISDIR(hidden_dir_dentry->d_inode->i_mode)) | ||
4621 | + continue; | ||
4622 | + | ||
4623 | + /* Reuse the whiteout name because its value doesn't change. */ | ||
4624 | + if (!whname) { | ||
4625 | + whname = alloc_whname(name, namelen); | ||
4626 | + if (IS_ERR(whname)) { | ||
4627 | + err = PTR_ERR(whname); | ||
4628 | + goto out_free; | ||
4629 | + } | ||
4630 | + } | ||
4631 | + | ||
4632 | + /* check if whiteout exists in this branch: lookup .wh.foo */ | ||
4633 | + wh_hidden_dentry = lookup_one_len(whname, hidden_dir_dentry, | ||
4634 | + namelen + UNIONFS_WHLEN); | ||
4635 | + if (IS_ERR(wh_hidden_dentry)) { | ||
4636 | + dput(first_hidden_dentry); | ||
4637 | + unionfs_mntput(first_dentry, first_dentry_offset); | ||
4638 | + err = PTR_ERR(wh_hidden_dentry); | ||
4639 | + goto out_free; | ||
4640 | + } | ||
4641 | + | ||
4642 | + if (wh_hidden_dentry->d_inode) { | ||
4643 | + /* We found a whiteout so lets give up. */ | ||
4644 | + if (S_ISREG(wh_hidden_dentry->d_inode->i_mode)) { | ||
4645 | + set_dbend(dentry, bindex); | ||
4646 | + set_dbopaque(dentry, bindex); | ||
4647 | + dput(wh_hidden_dentry); | ||
4648 | + break; | ||
4649 | + } | ||
4650 | + err = -EIO; | ||
4651 | + printk(KERN_NOTICE "EIO: Invalid whiteout entry type" | ||
4652 | + " %d.\n", wh_hidden_dentry->d_inode->i_mode); | ||
4653 | + dput(wh_hidden_dentry); | ||
4654 | + dput(first_hidden_dentry); | ||
4655 | + unionfs_mntput(first_dentry, first_dentry_offset); | ||
4656 | + goto out_free; | ||
4657 | + } | ||
4658 | + | ||
4659 | + dput(wh_hidden_dentry); | ||
4660 | + wh_hidden_dentry = NULL; | ||
4661 | + | ||
4662 | + /* Now do regular lookup; lookup foo */ | ||
4663 | + nd->dentry = unionfs_lower_dentry_idx(dentry, bindex); | ||
4664 | + /* FIXME: fix following line for mount point crossing */ | ||
4665 | + nd->mnt = unionfs_lower_mnt_idx(parent_dentry, bindex); | ||
4666 | + | ||
4667 | + hidden_dentry = lookup_one_len_nd(name, hidden_dir_dentry, | ||
4668 | + namelen, nd); | ||
4669 | + if (IS_ERR(hidden_dentry)) { | ||
4670 | + dput(first_hidden_dentry); | ||
4671 | + unionfs_mntput(first_dentry, first_dentry_offset); | ||
4672 | + err = PTR_ERR(hidden_dentry); | ||
4673 | + goto out_free; | ||
4674 | + } | ||
4675 | + | ||
4676 | + /* Store the first negative dentry specially, because if they | ||
4677 | + * are all negative we need this for future creates. | ||
4678 | + */ | ||
4679 | + if (!hidden_dentry->d_inode) { | ||
4680 | + if (!first_hidden_dentry && (dbstart(dentry) == -1)) { | ||
4681 | + first_hidden_dentry = hidden_dentry; | ||
4682 | + /* FIXME: following line needs to be changed | ||
4683 | + * to allow mountpoint crossing | ||
4684 | + */ | ||
4685 | + first_dentry = parent_dentry; | ||
4686 | + first_hidden_mnt = unionfs_mntget(parent_dentry, bindex); | ||
4687 | + first_dentry_offset = bindex; | ||
4688 | + } else | ||
4689 | + dput(hidden_dentry); | ||
4690 | + | ||
4691 | + continue; | ||
4692 | + } | ||
4693 | + | ||
4694 | + /* number of positive dentries */ | ||
4695 | + dentry_count++; | ||
4696 | + | ||
4697 | + /* store underlying dentry */ | ||
4698 | + if (dbstart(dentry) == -1) | ||
4699 | + set_dbstart(dentry, bindex); | ||
4700 | + unionfs_set_lower_dentry_idx(dentry, bindex, hidden_dentry); | ||
4701 | + /* FIXME: the following line needs to get fixed to allow | ||
4702 | + * mountpoint crossing | ||
4703 | + */ | ||
4704 | + unionfs_set_lower_mnt_idx(dentry, bindex, | ||
4705 | + unionfs_mntget(parent_dentry, bindex)); | ||
4706 | + set_dbend(dentry, bindex); | ||
4707 | + | ||
4708 | + /* update parent directory's atime with the bindex */ | ||
4709 | + fsstack_copy_attr_atime(parent_dentry->d_inode, | ||
4710 | + hidden_dir_dentry->d_inode); | ||
4711 | + | ||
4712 | + /* We terminate file lookups here. */ | ||
4713 | + if (!S_ISDIR(hidden_dentry->d_inode->i_mode)) { | ||
4714 | + if (lookupmode == INTERPOSE_PARTIAL) | ||
4715 | + continue; | ||
4716 | + if (dentry_count == 1) | ||
4717 | + goto out_positive; | ||
4718 | + /* This can only happen with mixed D-*-F-* */ | ||
4719 | + BUG_ON(!S_ISDIR(unionfs_lower_dentry(dentry)->d_inode->i_mode)); | ||
4720 | + continue; | ||
4721 | + } | ||
4722 | + | ||
4723 | + opaque = is_opaque_dir(dentry, bindex); | ||
4724 | + if (opaque < 0) { | ||
4725 | + dput(first_hidden_dentry); | ||
4726 | + unionfs_mntput(first_dentry, first_dentry_offset); | ||
4727 | + err = opaque; | ||
4728 | + goto out_free; | ||
4729 | + } else if (opaque) { | ||
4730 | + set_dbend(dentry, bindex); | ||
4731 | + set_dbopaque(dentry, bindex); | ||
4732 | + break; | ||
4733 | + } | ||
4734 | + } | ||
4735 | + | ||
4736 | + if (dentry_count) | ||
4737 | + goto out_positive; | ||
4738 | + else | ||
4739 | + goto out_negative; | ||
4740 | + | ||
4741 | +out_negative: | ||
4742 | + if (lookupmode == INTERPOSE_PARTIAL) | ||
4743 | + goto out; | ||
4744 | + | ||
4745 | + /* If we've only got negative dentries, then use the leftmost one. */ | ||
4746 | + if (lookupmode == INTERPOSE_REVAL) { | ||
4747 | + if (dentry->d_inode) | ||
4748 | + UNIONFS_I(dentry->d_inode)->stale = 1; | ||
4749 | + | ||
4750 | + goto out; | ||
4751 | + } | ||
4752 | + /* This should only happen if we found a whiteout. */ | ||
4753 | + if (first_dentry_offset == -1) { | ||
4754 | + nd->dentry = dentry; | ||
4755 | + /* FIXME: fix following line for mount point crossing */ | ||
4756 | + nd->mnt = unionfs_lower_mnt_idx(parent_dentry, bindex); | ||
4757 | + | ||
4758 | + first_hidden_dentry = lookup_one_len_nd(name, hidden_dir_dentry, | ||
4759 | + namelen, nd); | ||
4760 | + first_dentry_offset = bindex; | ||
4761 | + if (IS_ERR(first_hidden_dentry)) { | ||
4762 | + err = PTR_ERR(first_hidden_dentry); | ||
4763 | + goto out; | ||
4764 | + } | ||
4765 | + | ||
4766 | + /* FIXME: the following line needs to be changed to allow | ||
4767 | + * mountpoint crossing | ||
4768 | + */ | ||
4769 | + first_dentry = dentry; | ||
4770 | + first_hidden_mnt = unionfs_mntget(dentry, bindex); | ||
4771 | + } | ||
4772 | + unionfs_set_lower_dentry_idx(dentry, first_dentry_offset, first_hidden_dentry); | ||
4773 | + unionfs_set_lower_mnt_idx(dentry, first_dentry_offset, first_hidden_mnt); | ||
4774 | + set_dbstart(dentry, first_dentry_offset); | ||
4775 | + set_dbend(dentry, first_dentry_offset); | ||
4776 | + | ||
4777 | + if (lookupmode == INTERPOSE_REVAL_NEG) | ||
4778 | + BUG_ON(dentry->d_inode != NULL); | ||
4779 | + else | ||
4780 | + d_add(dentry, NULL); | ||
4781 | + goto out; | ||
4782 | + | ||
4783 | +/* This part of the code is for positive dentries. */ | ||
4784 | +out_positive: | ||
4785 | + BUG_ON(dentry_count <= 0); | ||
4786 | + | ||
4787 | + /* If we're holding onto the first negative dentry & corresponding | ||
4788 | + * vfsmount - throw it out. | ||
4789 | + */ | ||
4790 | + dput(first_hidden_dentry); | ||
4791 | + unionfs_mntput(first_dentry, first_dentry_offset); | ||
4792 | + | ||
4793 | + /* Partial lookups need to reinterpose, or throw away older negs. */ | ||
4794 | + if (lookupmode == INTERPOSE_PARTIAL) { | ||
4795 | + if (dentry->d_inode) { | ||
4796 | + unionfs_reinterpose(dentry); | ||
4797 | + goto out; | ||
4798 | + } | ||
4799 | + | ||
4800 | + /* This somehow turned positive, so it is as if we had a | ||
4801 | + * negative revalidation. | ||
4802 | + */ | ||
4803 | + lookupmode = INTERPOSE_REVAL_NEG; | ||
4804 | + | ||
4805 | + update_bstart(dentry); | ||
4806 | + bstart = dbstart(dentry); | ||
4807 | + bend = dbend(dentry); | ||
4808 | + } | ||
4809 | + | ||
4810 | + err = unionfs_interpose(dentry, dentry->d_sb, lookupmode); | ||
4811 | + if (err) | ||
4812 | + goto out_drop; | ||
4813 | + | ||
4814 | + goto out; | ||
4815 | + | ||
4816 | +out_drop: | ||
4817 | + d_drop(dentry); | ||
4818 | + | ||
4819 | +out_free: | ||
4820 | + /* should dput all the underlying dentries on error condition */ | ||
4821 | + bstart = dbstart(dentry); | ||
4822 | + if (bstart >= 0) { | ||
4823 | + bend = dbend(dentry); | ||
4824 | + for (bindex = bstart; bindex <= bend; bindex++) { | ||
4825 | + dput(unionfs_lower_dentry_idx(dentry, bindex)); | ||
4826 | + unionfs_mntput(dentry, bindex); | ||
4827 | + } | ||
4828 | + } | ||
4829 | + kfree(UNIONFS_D(dentry)->lower_paths); | ||
4830 | + UNIONFS_D(dentry)->lower_paths = NULL; | ||
4831 | + set_dbstart(dentry, -1); | ||
4832 | + set_dbend(dentry, -1); | ||
4833 | + | ||
4834 | +out: | ||
4835 | + if (!err && UNIONFS_D(dentry)) { | ||
4836 | + BUG_ON(dbend(dentry) > UNIONFS_D(dentry)->bcount); | ||
4837 | + BUG_ON(dbend(dentry) > sbmax(dentry->d_sb)); | ||
4838 | + BUG_ON(dbstart(dentry) < 0); | ||
4839 | + } | ||
4840 | + kfree(whname); | ||
4841 | + if (locked_parent) | ||
4842 | + unionfs_unlock_dentry(parent_dentry); | ||
4843 | + dput(parent_dentry); | ||
4844 | + if (locked_child || (err && allocated_new_info)) | ||
4845 | + unionfs_unlock_dentry(dentry); | ||
4846 | + return ERR_PTR(err); | ||
4847 | +} | ||
4848 | + | ||
4849 | +/* This is a utility function that fills in a unionfs dentry.*/ | ||
4850 | +int unionfs_partial_lookup(struct dentry *dentry) | ||
4851 | +{ | ||
4852 | + struct dentry *tmp; | ||
4853 | + struct nameidata nd = { .flags = 0 }; | ||
4854 | + | ||
4855 | + tmp = unionfs_lookup_backend(dentry, &nd, INTERPOSE_PARTIAL); | ||
4856 | + if (!tmp) | ||
4857 | + return 0; | ||
4858 | + if (IS_ERR(tmp)) | ||
4859 | + return PTR_ERR(tmp); | ||
4860 | + /* need to change the interface */ | ||
4861 | + BUG_ON(tmp != dentry); | ||
4862 | + return -ENOSYS; | ||
4863 | +} | ||
4864 | + | ||
4865 | +/* The dentry cache is just so we have properly sized dentries. */ | ||
4866 | +static struct kmem_cache *unionfs_dentry_cachep; | ||
4867 | +int unionfs_init_dentry_cache(void) | ||
4868 | +{ | ||
4869 | + unionfs_dentry_cachep = kmem_cache_create("unionfs_dentry", | ||
4870 | + sizeof(struct unionfs_dentry_info), 0, | ||
4871 | + SLAB_RECLAIM_ACCOUNT, NULL, NULL); | ||
4872 | + | ||
4873 | + return (unionfs_dentry_cachep ? 0 : -ENOMEM); | ||
4874 | +} | ||
4875 | + | ||
4876 | +void unionfs_destroy_dentry_cache(void) | ||
4877 | +{ | ||
4878 | + if (unionfs_dentry_cachep) | ||
4879 | + kmem_cache_destroy(unionfs_dentry_cachep); | ||
4880 | +} | ||
4881 | + | ||
4882 | +void free_dentry_private_data(struct unionfs_dentry_info *udi) | ||
4883 | +{ | ||
4884 | + if (!udi) | ||
4885 | + return; | ||
4886 | + kmem_cache_free(unionfs_dentry_cachep, udi); | ||
4887 | +} | ||
4888 | + | ||
4889 | +/* allocate new dentry private data, free old one if necessary */ | ||
4890 | +int new_dentry_private_data(struct dentry *dentry) | ||
4891 | +{ | ||
4892 | + int newsize; | ||
4893 | + int oldsize = 0; | ||
4894 | + struct unionfs_dentry_info *info = UNIONFS_D(dentry); | ||
4895 | + int unlock_on_err = 0; | ||
4896 | + | ||
4897 | + spin_lock(&dentry->d_lock); | ||
4898 | + if (!info) { | ||
4899 | + dentry->d_fsdata = kmem_cache_alloc(unionfs_dentry_cachep, | ||
4900 | + GFP_ATOMIC); | ||
4901 | + info = UNIONFS_D(dentry); | ||
4902 | + | ||
4903 | + if (!info) | ||
4904 | + goto out; | ||
4905 | + | ||
4906 | + mutex_init(&info->lock); | ||
4907 | + mutex_lock(&info->lock); | ||
4908 | + unlock_on_err = 1; | ||
4909 | + | ||
4910 | + info->lower_paths = NULL; | ||
4911 | + } else | ||
4912 | + oldsize = sizeof(struct path) * info->bcount; | ||
4913 | + | ||
4914 | + info->bstart = -1; | ||
4915 | + info->bend = -1; | ||
4916 | + info->bopaque = -1; | ||
4917 | + info->bcount = sbmax(dentry->d_sb); | ||
4918 | + atomic_set(&info->generation, | ||
4919 | + atomic_read(&UNIONFS_SB(dentry->d_sb)->generation)); | ||
4920 | + newsize = sizeof(struct path) * sbmax(dentry->d_sb); | ||
4921 | + | ||
4922 | + /* Don't reallocate when we already have enough space. */ | ||
4923 | + /* It would be ideal if we could actually use the slab macros to | ||
4924 | + * determine what our object sizes is, but those are not exported. | ||
4925 | + */ | ||
4926 | + if (oldsize) { | ||
4927 | + int minsize = malloc_sizes[0].cs_size; | ||
4928 | + | ||
4929 | + if (!newsize || ((oldsize < newsize) && (newsize > minsize))) { | ||
4930 | + kfree(info->lower_paths); | ||
4931 | + info->lower_paths = NULL; | ||
4932 | + } | ||
4933 | + } | ||
4934 | + | ||
4935 | + if (!info->lower_paths && newsize) { | ||
4936 | + info->lower_paths = kmalloc(newsize, GFP_ATOMIC); | ||
4937 | + if (!info->lower_paths) | ||
4938 | + goto out_free; | ||
4939 | + } | ||
4940 | + | ||
4941 | + memset(info->lower_paths, 0, (oldsize > newsize ? oldsize : newsize)); | ||
4942 | + | ||
4943 | + spin_unlock(&dentry->d_lock); | ||
4944 | + return 0; | ||
4945 | + | ||
4946 | +out_free: | ||
4947 | + kfree(info->lower_paths); | ||
4948 | + if (unlock_on_err) | ||
4949 | + mutex_unlock(&info->lock); | ||
4950 | + | ||
4951 | +out: | ||
4952 | + free_dentry_private_data(info); | ||
4953 | + dentry->d_fsdata = NULL; | ||
4954 | + spin_unlock(&dentry->d_lock); | ||
4955 | + return -ENOMEM; | ||
4956 | +} | ||
4957 | + | ||
4958 | +/* scan through the lower dentry objects, and set bstart to reflect the | ||
4959 | + * starting branch | ||
4960 | + */ | ||
4961 | +void update_bstart(struct dentry *dentry) | ||
4962 | +{ | ||
4963 | + int bindex; | ||
4964 | + int bstart = dbstart(dentry); | ||
4965 | + int bend = dbend(dentry); | ||
4966 | + struct dentry *hidden_dentry; | ||
4967 | + | ||
4968 | + for (bindex = bstart; bindex <= bend; bindex++) { | ||
4969 | + hidden_dentry = unionfs_lower_dentry_idx(dentry, bindex); | ||
4970 | + if (!hidden_dentry) | ||
4971 | + continue; | ||
4972 | + if (hidden_dentry->d_inode) { | ||
4973 | + set_dbstart(dentry, bindex); | ||
4974 | + break; | ||
4975 | + } | ||
4976 | + dput(hidden_dentry); | ||
4977 | + unionfs_set_lower_dentry_idx(dentry, bindex, NULL); | ||
4978 | + } | ||
4979 | +} | ||
4980 | + | ||
4981 | diff --git a/fs/unionfs/main.c b/fs/unionfs/main.c | ||
4982 | new file mode 100644 | ||
4983 | index 0000000..4fffafa | ||
4984 | --- /dev/null | ||
4985 | +++ b/fs/unionfs/main.c | ||
4986 | @@ -0,0 +1,703 @@ | ||
4987 | +/* | ||
4988 | + * Copyright (c) 2003-2007 Erez Zadok | ||
4989 | + * Copyright (c) 2003-2006 Charles P. Wright | ||
4990 | + * Copyright (c) 2005-2007 Josef 'Jeff' Sipek | ||
4991 | + * Copyright (c) 2005-2006 Junjiro Okajima | ||
4992 | + * Copyright (c) 2005 Arun M. Krishnakumar | ||
4993 | + * Copyright (c) 2004-2006 David P. Quigley | ||
4994 | + * Copyright (c) 2003-2004 Mohammad Nayyer Zubair | ||
4995 | + * Copyright (c) 2003 Puja Gupta | ||
4996 | + * Copyright (c) 2003 Harikesavan Krishnan | ||
4997 | + * Copyright (c) 2003-2007 Stony Brook University | ||
4998 | + * Copyright (c) 2003-2007 The Research Foundation of State University of New York | ||
4999 | + * | ||
5000 | + * This program is free software; you can redistribute it and/or modify | ||
5001 | + * it under the terms of the GNU General Public License version 2 as | ||
5002 | + * published by the Free Software Foundation. | ||
5003 | + */ | ||
5004 | + | ||
5005 | +#include "union.h" | ||
5006 | +#include <linux/module.h> | ||
5007 | +#include <linux/moduleparam.h> | ||
5008 | + | ||
5009 | +/* sb we pass is unionfs's super_block */ | ||
5010 | +int unionfs_interpose(struct dentry *dentry, struct super_block *sb, int flag) | ||
5011 | +{ | ||
5012 | + struct inode *hidden_inode; | ||
5013 | + struct dentry *hidden_dentry; | ||
5014 | + int err = 0; | ||
5015 | + struct inode *inode; | ||
5016 | + int is_negative_dentry = 1; | ||
5017 | + int bindex, bstart, bend; | ||
5018 | + | ||
5019 | + verify_locked(dentry); | ||
5020 | + | ||
5021 | + bstart = dbstart(dentry); | ||
5022 | + bend = dbend(dentry); | ||
5023 | + | ||
5024 | + /* Make sure that we didn't get a negative dentry. */ | ||
5025 | + for (bindex = bstart; bindex <= bend; bindex++) { | ||
5026 | + if (unionfs_lower_dentry_idx(dentry, bindex) && | ||
5027 | + unionfs_lower_dentry_idx(dentry, bindex)->d_inode) { | ||
5028 | + is_negative_dentry = 0; | ||
5029 | + break; | ||
5030 | + } | ||
5031 | + } | ||
5032 | + BUG_ON(is_negative_dentry); | ||
5033 | + | ||
5034 | + /* We allocate our new inode below, by calling iget. | ||
5035 | + * iget will call our read_inode which will initialize some | ||
5036 | + * of the new inode's fields | ||
5037 | + */ | ||
5038 | + | ||
5039 | + /* On revalidate we've already got our own inode and just need | ||
5040 | + * to fix it up. | ||
5041 | + */ | ||
5042 | + if (flag == INTERPOSE_REVAL) { | ||
5043 | + inode = dentry->d_inode; | ||
5044 | + UNIONFS_I(inode)->bstart = -1; | ||
5045 | + UNIONFS_I(inode)->bend = -1; | ||
5046 | + atomic_set(&UNIONFS_I(inode)->generation, | ||
5047 | + atomic_read(&UNIONFS_SB(sb)->generation)); | ||
5048 | + | ||
5049 | + UNIONFS_I(inode)->lower_inodes = | ||
5050 | + kcalloc(sbmax(sb), sizeof(struct inode *), GFP_KERNEL); | ||
5051 | + if (!UNIONFS_I(inode)->lower_inodes) { | ||
5052 | + err = -ENOMEM; | ||
5053 | + goto out; | ||
5054 | + } | ||
5055 | + } else { | ||
5056 | + /* get unique inode number for unionfs */ | ||
5057 | + inode = iget(sb, iunique(sb, UNIONFS_ROOT_INO)); | ||
5058 | + if (!inode) { | ||
5059 | + err = -EACCES; | ||
5060 | + goto out; | ||
5061 | + } | ||
5062 | + | ||
5063 | + if (atomic_read(&inode->i_count) > 1) | ||
5064 | + goto skip; | ||
5065 | + } | ||
5066 | + | ||
5067 | + for (bindex = bstart; bindex <= bend; bindex++) { | ||
5068 | + hidden_dentry = unionfs_lower_dentry_idx(dentry, bindex); | ||
5069 | + if (!hidden_dentry) { | ||
5070 | + unionfs_set_lower_inode_idx(inode, bindex, NULL); | ||
5071 | + continue; | ||
5072 | + } | ||
5073 | + | ||
5074 | + /* Initialize the hidden inode to the new hidden inode. */ | ||
5075 | + if (!hidden_dentry->d_inode) | ||
5076 | + continue; | ||
5077 | + | ||
5078 | + unionfs_set_lower_inode_idx(inode, bindex, | ||
5079 | + igrab(hidden_dentry->d_inode)); | ||
5080 | + } | ||
5081 | + | ||
5082 | + ibstart(inode) = dbstart(dentry); | ||
5083 | + ibend(inode) = dbend(dentry); | ||
5084 | + | ||
5085 | + /* Use attributes from the first branch. */ | ||
5086 | + hidden_inode = unionfs_lower_inode(inode); | ||
5087 | + | ||
5088 | + /* Use different set of inode ops for symlinks & directories */ | ||
5089 | + if (S_ISLNK(hidden_inode->i_mode)) | ||
5090 | + inode->i_op = &unionfs_symlink_iops; | ||
5091 | + else if (S_ISDIR(hidden_inode->i_mode)) | ||
5092 | + inode->i_op = &unionfs_dir_iops; | ||
5093 | + | ||
5094 | + /* Use different set of file ops for directories */ | ||
5095 | + if (S_ISDIR(hidden_inode->i_mode)) | ||
5096 | + inode->i_fop = &unionfs_dir_fops; | ||
5097 | + | ||
5098 | + /* properly initialize special inodes */ | ||
5099 | + if (S_ISBLK(hidden_inode->i_mode) || S_ISCHR(hidden_inode->i_mode) || | ||
5100 | + S_ISFIFO(hidden_inode->i_mode) || S_ISSOCK(hidden_inode->i_mode)) | ||
5101 | + init_special_inode(inode, hidden_inode->i_mode, | ||
5102 | + hidden_inode->i_rdev); | ||
5103 | + /* Fix our inode's address operations to that of the lower inode | ||
5104 | + * (Unionfs is FiST-Lite) | ||
5105 | + */ | ||
5106 | + if (inode->i_mapping->a_ops != hidden_inode->i_mapping->a_ops) | ||
5107 | + inode->i_mapping->a_ops = hidden_inode->i_mapping->a_ops; | ||
5108 | + | ||
5109 | + /* all well, copy inode attributes */ | ||
5110 | + fsstack_copy_attr_all(inode, hidden_inode, unionfs_get_nlinks); | ||
5111 | + fsstack_copy_inode_size(inode, hidden_inode); | ||
5112 | + | ||
5113 | +skip: | ||
5114 | + /* only (our) lookup wants to do a d_add */ | ||
5115 | + switch (flag) { | ||
5116 | + case INTERPOSE_DEFAULT: | ||
5117 | + case INTERPOSE_REVAL_NEG: | ||
5118 | + d_instantiate(dentry, inode); | ||
5119 | + break; | ||
5120 | + case INTERPOSE_LOOKUP: | ||
5121 | + err = PTR_ERR(d_splice_alias(inode, dentry)); | ||
5122 | + break; | ||
5123 | + case INTERPOSE_REVAL: | ||
5124 | + /* Do nothing. */ | ||
5125 | + break; | ||
5126 | + default: | ||
5127 | + printk(KERN_ERR "Invalid interpose flag passed!"); | ||
5128 | + BUG(); | ||
5129 | + } | ||
5130 | + | ||
5131 | +out: | ||
5132 | + return err; | ||
5133 | +} | ||
5134 | + | ||
5135 | +void unionfs_reinterpose(struct dentry *dentry) | ||
5136 | +{ | ||
5137 | + struct dentry *hidden_dentry; | ||
5138 | + struct inode *inode; | ||
5139 | + int bindex, bstart, bend; | ||
5140 | + | ||
5141 | + verify_locked(dentry); | ||
5142 | + | ||
5143 | + /* This is pre-allocated inode */ | ||
5144 | + inode = dentry->d_inode; | ||
5145 | + | ||
5146 | + bstart = dbstart(dentry); | ||
5147 | + bend = dbend(dentry); | ||
5148 | + for (bindex = bstart; bindex <= bend; bindex++) { | ||
5149 | + hidden_dentry = unionfs_lower_dentry_idx(dentry, bindex); | ||
5150 | + if (!hidden_dentry) | ||
5151 | + continue; | ||
5152 | + | ||
5153 | + if (!hidden_dentry->d_inode) | ||
5154 | + continue; | ||
5155 | + if (unionfs_lower_inode_idx(inode, bindex)) | ||
5156 | + continue; | ||
5157 | + unionfs_set_lower_inode_idx(inode, bindex, | ||
5158 | + igrab(hidden_dentry->d_inode)); | ||
5159 | + } | ||
5160 | + ibstart(inode) = dbstart(dentry); | ||
5161 | + ibend(inode) = dbend(dentry); | ||
5162 | +} | ||
5163 | + | ||
5164 | +/* make sure the branch we just looked up (nd) makes sense: | ||
5165 | + * | ||
5166 | + * 1) we're not trying to stack unionfs on top of unionfs | ||
5167 | + * 2) it exists | ||
5168 | + * 3) is a directory | ||
5169 | + */ | ||
5170 | +int check_branch(struct nameidata *nd) | ||
5171 | +{ | ||
5172 | + if (!strcmp(nd->dentry->d_sb->s_type->name, "unionfs")) | ||
5173 | + return -EINVAL; | ||
5174 | + if (!nd->dentry->d_inode) | ||
5175 | + return -ENOENT; | ||
5176 | + if (!S_ISDIR(nd->dentry->d_inode->i_mode)) | ||
5177 | + return -ENOTDIR; | ||
5178 | + return 0; | ||
5179 | +} | ||
5180 | + | ||
5181 | +/* checks if two hidden_dentries have overlapping branches */ | ||
5182 | +static int is_branch_overlap(struct dentry *dent1, struct dentry *dent2) | ||
5183 | +{ | ||
5184 | + struct dentry *dent = NULL; | ||
5185 | + | ||
5186 | + dent = dent1; | ||
5187 | + while ((dent != dent2) && (dent->d_parent != dent)) | ||
5188 | + dent = dent->d_parent; | ||
5189 | + | ||
5190 | + if (dent == dent2) | ||
5191 | + return 1; | ||
5192 | + | ||
5193 | + dent = dent2; | ||
5194 | + while ((dent != dent1) && (dent->d_parent != dent)) | ||
5195 | + dent = dent->d_parent; | ||
5196 | + | ||
5197 | + return (dent == dent1); | ||
5198 | +} | ||
5199 | + | ||
5200 | +/* | ||
5201 | + * Parse branch mode helper function | ||
5202 | + */ | ||
5203 | +int __parse_branch_mode(const char *name) | ||
5204 | +{ | ||
5205 | + if (!name) | ||
5206 | + return 0; | ||
5207 | + if (!strcmp(name, "ro")) | ||
5208 | + return MAY_READ; | ||
5209 | + if (!strcmp(name, "rw")) | ||
5210 | + return (MAY_READ | MAY_WRITE); | ||
5211 | + return 0; | ||
5212 | +} | ||
5213 | + | ||
5214 | +/* | ||
5215 | + * Parse "ro" or "rw" options, but default to "rw" of no mode options | ||
5216 | + * was specified. | ||
5217 | + */ | ||
5218 | +int parse_branch_mode(const char *name) | ||
5219 | +{ | ||
5220 | + int perms = __parse_branch_mode(name); | ||
5221 | + if (perms == 0) | ||
5222 | + perms = MAY_READ | MAY_WRITE; | ||
5223 | + return perms; | ||
5224 | +} | ||
5225 | + | ||
5226 | +/* parse the dirs= mount argument */ | ||
5227 | +static int parse_dirs_option(struct super_block *sb, struct unionfs_dentry_info | ||
5228 | + *hidden_root_info, char *options) | ||
5229 | +{ | ||
5230 | + struct nameidata nd; | ||
5231 | + char *name; | ||
5232 | + int err = 0; | ||
5233 | + int branches = 1; | ||
5234 | + int bindex = 0; | ||
5235 | + int i = 0; | ||
5236 | + int j = 0; | ||
5237 | + | ||
5238 | + struct dentry *dent1; | ||
5239 | + struct dentry *dent2; | ||
5240 | + | ||
5241 | + if (options[0] == '\0') { | ||
5242 | + printk(KERN_WARNING "unionfs: no branches specified\n"); | ||
5243 | + err = -EINVAL; | ||
5244 | + goto out; | ||
5245 | + } | ||
5246 | + | ||
5247 | + /* Each colon means we have a separator, this is really just a rough | ||
5248 | + * guess, since strsep will handle empty fields for us. | ||
5249 | + */ | ||
5250 | + for (i = 0; options[i]; i++) | ||
5251 | + if (options[i] == ':') | ||
5252 | + branches++; | ||
5253 | + | ||
5254 | + /* allocate space for underlying pointers to hidden dentry */ | ||
5255 | + UNIONFS_SB(sb)->data = kcalloc(branches, | ||
5256 | + sizeof(struct unionfs_data), GFP_KERNEL); | ||
5257 | + if (!UNIONFS_SB(sb)->data) { | ||
5258 | + err = -ENOMEM; | ||
5259 | + goto out; | ||
5260 | + } | ||
5261 | + | ||
5262 | + hidden_root_info->lower_paths = kcalloc(branches, | ||
5263 | + sizeof(struct path), GFP_KERNEL); | ||
5264 | + if (!hidden_root_info->lower_paths) { | ||
5265 | + err = -ENOMEM; | ||
5266 | + goto out; | ||
5267 | + } | ||
5268 | + | ||
5269 | + /* now parsing a string such as "b1:b2=rw:b3=ro:b4" */ | ||
5270 | + branches = 0; | ||
5271 | + while ((name = strsep(&options, ":")) != NULL) { | ||
5272 | + int perms; | ||
5273 | + char *mode = strchr(name, '='); | ||
5274 | + | ||
5275 | + if (!name || !*name) | ||
5276 | + continue; | ||
5277 | + | ||
5278 | + branches++; | ||
5279 | + | ||
5280 | + /* strip off '=' if any */ | ||
5281 | + if (mode) | ||
5282 | + *mode++ = '\0'; | ||
5283 | + | ||
5284 | + perms = parse_branch_mode(mode); | ||
5285 | + if (!bindex && !(perms & MAY_WRITE)) { | ||
5286 | + err = -EINVAL; | ||
5287 | + goto out; | ||
5288 | + } | ||
5289 | + | ||
5290 | + err = path_lookup(name, LOOKUP_FOLLOW, &nd); | ||
5291 | + if (err) { | ||
5292 | + printk(KERN_WARNING "unionfs: error accessing " | ||
5293 | + "hidden directory '%s' (error %d)\n", name, err); | ||
5294 | + goto out; | ||
5295 | + } | ||
5296 | + | ||
5297 | + if ((err = check_branch(&nd))) { | ||
5298 | + printk(KERN_WARNING "unionfs: hidden directory " | ||
5299 | + "'%s' is not a valid branch\n", name); | ||
5300 | + path_release(&nd); | ||
5301 | + goto out; | ||
5302 | + } | ||
5303 | + | ||
5304 | + hidden_root_info->lower_paths[bindex].dentry = nd.dentry; | ||
5305 | + hidden_root_info->lower_paths[bindex].mnt = nd.mnt; | ||
5306 | + | ||
5307 | + unionfs_write_lock(sb); | ||
5308 | + set_branchperms(sb, bindex, perms); | ||
5309 | + set_branch_count(sb, bindex, 0); | ||
5310 | + new_branch_id(sb, bindex); | ||
5311 | + unionfs_write_unlock(sb); | ||
5312 | + | ||
5313 | + if (hidden_root_info->bstart < 0) | ||
5314 | + hidden_root_info->bstart = bindex; | ||
5315 | + hidden_root_info->bend = bindex; | ||
5316 | + bindex++; | ||
5317 | + } | ||
5318 | + | ||
5319 | + if (branches == 0) { | ||
5320 | + printk(KERN_WARNING "unionfs: no branches specified\n"); | ||
5321 | + err = -EINVAL; | ||
5322 | + goto out; | ||
5323 | + } | ||
5324 | + | ||
5325 | + BUG_ON(branches != (hidden_root_info->bend + 1)); | ||
5326 | + | ||
5327 | + /* ensure that no overlaps exist in the branches */ | ||
5328 | + for (i = 0; i < branches; i++) { | ||
5329 | + for (j = i + 1; j < branches; j++) { | ||
5330 | + dent1 = hidden_root_info->lower_paths[i].dentry; | ||
5331 | + dent2 = hidden_root_info->lower_paths[j].dentry; | ||
5332 | + | ||
5333 | + if (is_branch_overlap(dent1, dent2)) { | ||
5334 | + printk(KERN_WARNING "unionfs: branches %d and " | ||
5335 | + "%d overlap\n", i, j); | ||
5336 | + err = -EINVAL; | ||
5337 | + goto out; | ||
5338 | + } | ||
5339 | + } | ||
5340 | + } | ||
5341 | + | ||
5342 | +out: | ||
5343 | + if (err) { | ||
5344 | + for (i = 0; i < branches; i++) | ||
5345 | + if (hidden_root_info->lower_paths[i].dentry) { | ||
5346 | + dput(hidden_root_info->lower_paths[i].dentry); | ||
5347 | + /* initializing: can't use unionfs_mntput here */ | ||
5348 | + mntput(hidden_root_info->lower_paths[i].mnt); | ||
5349 | + } | ||
5350 | + | ||
5351 | + kfree(hidden_root_info->lower_paths); | ||
5352 | + kfree(UNIONFS_SB(sb)->data); | ||
5353 | + | ||
5354 | + /* MUST clear the pointers to prevent potential double free if | ||
5355 | + * the caller dies later on | ||
5356 | + */ | ||
5357 | + hidden_root_info->lower_paths = NULL; | ||
5358 | + UNIONFS_SB(sb)->data = NULL; | ||
5359 | + } | ||
5360 | + return err; | ||
5361 | +} | ||
5362 | + | ||
5363 | +/* | ||
5364 | + * Parse mount options. See the manual page for usage instructions. | ||
5365 | + * | ||
5366 | + * Returns the dentry object of the lower-level (hidden) directory; | ||
5367 | + * We want to mount our stackable file system on top of that hidden directory. | ||
5368 | + */ | ||
5369 | +static struct unionfs_dentry_info *unionfs_parse_options(struct super_block *sb, | ||
5370 | + char *options) | ||
5371 | +{ | ||
5372 | + struct unionfs_dentry_info *hidden_root_info; | ||
5373 | + char *optname; | ||
5374 | + int err = 0; | ||
5375 | + int bindex; | ||
5376 | + int dirsfound = 0; | ||
5377 | + | ||
5378 | + /* allocate private data area */ | ||
5379 | + err = -ENOMEM; | ||
5380 | + hidden_root_info = | ||
5381 | + kzalloc(sizeof(struct unionfs_dentry_info), GFP_KERNEL); | ||
5382 | + if (!hidden_root_info) | ||
5383 | + goto out_error; | ||
5384 | + hidden_root_info->bstart = -1; | ||
5385 | + hidden_root_info->bend = -1; | ||
5386 | + hidden_root_info->bopaque = -1; | ||
5387 | + | ||
5388 | + while ((optname = strsep(&options, ",")) != NULL) { | ||
5389 | + char *optarg; | ||
5390 | + char *endptr; | ||
5391 | + int intval; | ||
5392 | + | ||
5393 | + if (!optname || !*optname) | ||
5394 | + continue; | ||
5395 | + | ||
5396 | + optarg = strchr(optname, '='); | ||
5397 | + if (optarg) | ||
5398 | + *optarg++ = '\0'; | ||
5399 | + | ||
5400 | + /* All of our options take an argument now. Insert ones that | ||
5401 | + * don't, above this check. | ||
5402 | + */ | ||
5403 | + if (!optarg) { | ||
5404 | + printk("unionfs: %s requires an argument.\n", optname); | ||
5405 | + err = -EINVAL; | ||
5406 | + goto out_error; | ||
5407 | + } | ||
5408 | + | ||
5409 | + if (!strcmp("dirs", optname)) { | ||
5410 | + if (++dirsfound > 1) { | ||
5411 | + printk(KERN_WARNING | ||
5412 | + "unionfs: multiple dirs specified\n"); | ||
5413 | + err = -EINVAL; | ||
5414 | + goto out_error; | ||
5415 | + } | ||
5416 | + err = parse_dirs_option(sb, hidden_root_info, optarg); | ||
5417 | + if (err) | ||
5418 | + goto out_error; | ||
5419 | + continue; | ||
5420 | + } | ||
5421 | + | ||
5422 | + /* All of these options require an integer argument. */ | ||
5423 | + intval = simple_strtoul(optarg, &endptr, 0); | ||
5424 | + if (*endptr) { | ||
5425 | + printk(KERN_WARNING | ||
5426 | + "unionfs: invalid %s option '%s'\n", | ||
5427 | + optname, optarg); | ||
5428 | + err = -EINVAL; | ||
5429 | + goto out_error; | ||
5430 | + } | ||
5431 | + | ||
5432 | + err = -EINVAL; | ||
5433 | + printk(KERN_WARNING | ||
5434 | + "unionfs: unrecognized option '%s'\n", optname); | ||
5435 | + goto out_error; | ||
5436 | + } | ||
5437 | + if (dirsfound != 1) { | ||
5438 | + printk(KERN_WARNING "unionfs: dirs option required\n"); | ||
5439 | + err = -EINVAL; | ||
5440 | + goto out_error; | ||
5441 | + } | ||
5442 | + goto out; | ||
5443 | + | ||
5444 | +out_error: | ||
5445 | + if (hidden_root_info && hidden_root_info->lower_paths) { | ||
5446 | + for (bindex = hidden_root_info->bstart; | ||
5447 | + bindex >= 0 && bindex <= hidden_root_info->bend; | ||
5448 | + bindex++) { | ||
5449 | + struct dentry *d; | ||
5450 | + struct vfsmount *m; | ||
5451 | + | ||
5452 | + d = hidden_root_info->lower_paths[bindex].dentry; | ||
5453 | + m = hidden_root_info->lower_paths[bindex].mnt; | ||
5454 | + | ||
5455 | + dput(d); | ||
5456 | + /* initializing: can't use unionfs_mntput here */ | ||
5457 | + mntput(m); | ||
5458 | + } | ||
5459 | + } | ||
5460 | + | ||
5461 | + kfree(hidden_root_info->lower_paths); | ||
5462 | + kfree(hidden_root_info); | ||
5463 | + | ||
5464 | + kfree(UNIONFS_SB(sb)->data); | ||
5465 | + UNIONFS_SB(sb)->data = NULL; | ||
5466 | + | ||
5467 | + hidden_root_info = ERR_PTR(err); | ||
5468 | +out: | ||
5469 | + return hidden_root_info; | ||
5470 | +} | ||
5471 | + | ||
5472 | +/* our custom d_alloc_root workalike | ||
5473 | + * | ||
5474 | + * we can't use d_alloc_root if we want to use our own interpose function | ||
5475 | + * unchanged, so we simply call our own "fake" d_alloc_root | ||
5476 | + */ | ||
5477 | +static struct dentry *unionfs_d_alloc_root(struct super_block *sb) | ||
5478 | +{ | ||
5479 | + struct dentry *ret = NULL; | ||
5480 | + | ||
5481 | + if (sb) { | ||
5482 | + static const struct qstr name = {.name = "/",.len = 1 }; | ||
5483 | + | ||
5484 | + ret = d_alloc(NULL, &name); | ||
5485 | + if (ret) { | ||
5486 | + ret->d_op = &unionfs_dops; | ||
5487 | + ret->d_sb = sb; | ||
5488 | + ret->d_parent = ret; | ||
5489 | + } | ||
5490 | + } | ||
5491 | + return ret; | ||
5492 | +} | ||
5493 | + | ||
5494 | +static int unionfs_read_super(struct super_block *sb, void *raw_data, | ||
5495 | + int silent) | ||
5496 | +{ | ||
5497 | + int err = 0; | ||
5498 | + | ||
5499 | + struct unionfs_dentry_info *hidden_root_info = NULL; | ||
5500 | + int bindex, bstart, bend; | ||
5501 | + | ||
5502 | + if (!raw_data) { | ||
5503 | + printk(KERN_WARNING | ||
5504 | + "unionfs_read_super: missing data argument\n"); | ||
5505 | + err = -EINVAL; | ||
5506 | + goto out; | ||
5507 | + } | ||
5508 | + | ||
5509 | + /* Allocate superblock private data */ | ||
5510 | + sb->s_fs_info = kzalloc(sizeof(struct unionfs_sb_info), GFP_KERNEL); | ||
5511 | + if (!UNIONFS_SB(sb)) { | ||
5512 | + printk(KERN_WARNING "%s: out of memory\n", __FUNCTION__); | ||
5513 | + err = -ENOMEM; | ||
5514 | + goto out; | ||
5515 | + } | ||
5516 | + | ||
5517 | + UNIONFS_SB(sb)->bend = -1; | ||
5518 | + atomic_set(&UNIONFS_SB(sb)->generation, 1); | ||
5519 | + init_rwsem(&UNIONFS_SB(sb)->rwsem); | ||
5520 | + UNIONFS_SB(sb)->high_branch_id = -1; /* -1 == invalid branch ID */ | ||
5521 | + | ||
5522 | + hidden_root_info = unionfs_parse_options(sb, raw_data); | ||
5523 | + if (IS_ERR(hidden_root_info)) { | ||
5524 | + printk(KERN_WARNING | ||
5525 | + "unionfs_read_super: error while parsing options " | ||
5526 | + "(err = %ld)\n", PTR_ERR(hidden_root_info)); | ||
5527 | + err = PTR_ERR(hidden_root_info); | ||
5528 | + hidden_root_info = NULL; | ||
5529 | + goto out_free; | ||
5530 | + } | ||
5531 | + if (hidden_root_info->bstart == -1) { | ||
5532 | + err = -ENOENT; | ||
5533 | + goto out_free; | ||
5534 | + } | ||
5535 | + | ||
5536 | + /* set the hidden superblock field of upper superblock */ | ||
5537 | + bstart = hidden_root_info->bstart; | ||
5538 | + BUG_ON(bstart != 0); | ||
5539 | + sbend(sb) = bend = hidden_root_info->bend; | ||
5540 | + for (bindex = bstart; bindex <= bend; bindex++) { | ||
5541 | + struct dentry *d; | ||
5542 | + | ||
5543 | + d = hidden_root_info->lower_paths[bindex].dentry; | ||
5544 | + | ||
5545 | + unionfs_write_lock(sb); | ||
5546 | + unionfs_set_lower_super_idx(sb, bindex, d->d_sb); | ||
5547 | + unionfs_write_unlock(sb); | ||
5548 | + } | ||
5549 | + | ||
5550 | + /* Unionfs: Max Bytes is the maximum bytes from highest priority branch */ | ||
5551 | + unionfs_read_lock(sb); | ||
5552 | + sb->s_maxbytes = unionfs_lower_super_idx(sb, 0)->s_maxbytes; | ||
5553 | + unionfs_read_unlock(sb); | ||
5554 | + | ||
5555 | + sb->s_op = &unionfs_sops; | ||
5556 | + | ||
5557 | + /* See comment next to the definition of unionfs_d_alloc_root */ | ||
5558 | + sb->s_root = unionfs_d_alloc_root(sb); | ||
5559 | + if (!sb->s_root) { | ||
5560 | + err = -ENOMEM; | ||
5561 | + goto out_dput; | ||
5562 | + } | ||
5563 | + | ||
5564 | + /* link the upper and lower dentries */ | ||
5565 | + sb->s_root->d_fsdata = NULL; | ||
5566 | + if ((err = new_dentry_private_data(sb->s_root))) | ||
5567 | + goto out_freedpd; | ||
5568 | + | ||
5569 | + /* Set the hidden dentries for s_root */ | ||
5570 | + for (bindex = bstart; bindex <= bend; bindex++) { | ||
5571 | + struct dentry *d; | ||
5572 | + struct vfsmount *m; | ||
5573 | + | ||
5574 | + d = hidden_root_info->lower_paths[bindex].dentry; | ||
5575 | + m = hidden_root_info->lower_paths[bindex].mnt; | ||
5576 | + | ||
5577 | + unionfs_set_lower_dentry_idx(sb->s_root, bindex, d); | ||
5578 | + unionfs_set_lower_mnt_idx(sb->s_root, bindex, m); | ||
5579 | + } | ||
5580 | + set_dbstart(sb->s_root, bstart); | ||
5581 | + set_dbend(sb->s_root, bend); | ||
5582 | + | ||
5583 | + /* Set the generation number to one, since this is for the mount. */ | ||
5584 | + atomic_set(&UNIONFS_D(sb->s_root)->generation, 1); | ||
5585 | + | ||
5586 | + /* call interpose to create the upper level inode */ | ||
5587 | + err = unionfs_interpose(sb->s_root, sb, 0); | ||
5588 | + unionfs_unlock_dentry(sb->s_root); | ||
5589 | + if (!err) | ||
5590 | + goto out; | ||
5591 | + /* else fall through */ | ||
5592 | + | ||
5593 | +out_freedpd: | ||
5594 | + if (UNIONFS_D(sb->s_root)) { | ||
5595 | + kfree(UNIONFS_D(sb->s_root)->lower_paths); | ||
5596 | + free_dentry_private_data(UNIONFS_D(sb->s_root)); | ||
5597 | + } | ||
5598 | + dput(sb->s_root); | ||
5599 | + | ||
5600 | +out_dput: | ||
5601 | + if (hidden_root_info && !IS_ERR(hidden_root_info)) { | ||
5602 | + for (bindex = hidden_root_info->bstart; | ||
5603 | + bindex <= hidden_root_info->bend; bindex++) { | ||
5604 | + struct dentry *d; | ||
5605 | + struct vfsmount *m; | ||
5606 | + | ||
5607 | + d = hidden_root_info->lower_paths[bindex].dentry; | ||
5608 | + m = hidden_root_info->lower_paths[bindex].mnt; | ||
5609 | + | ||
5610 | + dput(d); | ||
5611 | + /* initializing: can't use unionfs_mntput here */ | ||
5612 | + mntput(m); | ||
5613 | + } | ||
5614 | + kfree(hidden_root_info->lower_paths); | ||
5615 | + kfree(hidden_root_info); | ||
5616 | + hidden_root_info = NULL; | ||
5617 | + } | ||
5618 | + | ||
5619 | +out_free: | ||
5620 | + kfree(UNIONFS_SB(sb)->data); | ||
5621 | + kfree(UNIONFS_SB(sb)); | ||
5622 | + sb->s_fs_info = NULL; | ||
5623 | + | ||
5624 | +out: | ||
5625 | + if (hidden_root_info && !IS_ERR(hidden_root_info)) { | ||
5626 | + kfree(hidden_root_info->lower_paths); | ||
5627 | + kfree(hidden_root_info); | ||
5628 | + } | ||
5629 | + return err; | ||
5630 | +} | ||
5631 | + | ||
5632 | +static int unionfs_get_sb(struct file_system_type *fs_type, | ||
5633 | + int flags, const char *dev_name, | ||
5634 | + void *raw_data, struct vfsmount *mnt) | ||
5635 | +{ | ||
5636 | + return get_sb_nodev(fs_type, flags, raw_data, unionfs_read_super, mnt); | ||
5637 | +} | ||
5638 | + | ||
5639 | +static struct file_system_type unionfs_fs_type = { | ||
5640 | + .owner = THIS_MODULE, | ||
5641 | + .name = "unionfs", | ||
5642 | + .get_sb = unionfs_get_sb, | ||
5643 | + .kill_sb = generic_shutdown_super, | ||
5644 | + .fs_flags = FS_REVAL_DOT, | ||
5645 | +}; | ||
5646 | + | ||
5647 | +static int __init init_unionfs_fs(void) | ||
5648 | +{ | ||
5649 | + int err; | ||
5650 | + printk("Registering unionfs " UNIONFS_VERSION "\n"); | ||
5651 | + | ||
5652 | + if ((err = unionfs_init_filldir_cache())) | ||
5653 | + goto out; | ||
5654 | + if ((err = unionfs_init_inode_cache())) | ||
5655 | + goto out; | ||
5656 | + if ((err = unionfs_init_dentry_cache())) | ||
5657 | + goto out; | ||
5658 | + if ((err = init_sioq())) | ||
5659 | + goto out; | ||
5660 | + err = register_filesystem(&unionfs_fs_type); | ||
5661 | +out: | ||
5662 | + if (err) { | ||
5663 | + stop_sioq(); | ||
5664 | + unionfs_destroy_filldir_cache(); | ||
5665 | + unionfs_destroy_inode_cache(); | ||
5666 | + unionfs_destroy_dentry_cache(); | ||
5667 | + } | ||
5668 | + return err; | ||
5669 | +} | ||
5670 | + | ||
5671 | +static void __exit exit_unionfs_fs(void) | ||
5672 | +{ | ||
5673 | + stop_sioq(); | ||
5674 | + unionfs_destroy_filldir_cache(); | ||
5675 | + unionfs_destroy_inode_cache(); | ||
5676 | + unionfs_destroy_dentry_cache(); | ||
5677 | + unregister_filesystem(&unionfs_fs_type); | ||
5678 | + printk("Completed unionfs module unload.\n"); | ||
5679 | +} | ||
5680 | + | ||
5681 | +MODULE_AUTHOR("Erez Zadok, Filesystems and Storage Lab, Stony Brook University" | ||
5682 | + " (http://www.fsl.cs.sunysb.edu)"); | ||
5683 | +MODULE_DESCRIPTION("Unionfs " UNIONFS_VERSION | ||
5684 | + " (http://unionfs.filesystems.org)"); | ||
5685 | +MODULE_LICENSE("GPL"); | ||
5686 | + | ||
5687 | +module_init(init_unionfs_fs); | ||
5688 | +module_exit(exit_unionfs_fs); | ||
5689 | + | ||
5690 | diff --git a/fs/unionfs/rdstate.c b/fs/unionfs/rdstate.c | ||
5691 | new file mode 100644 | ||
5692 | index 0000000..b67a86a | ||
5693 | --- /dev/null | ||
5694 | +++ b/fs/unionfs/rdstate.c | ||
5695 | @@ -0,0 +1,275 @@ | ||
5696 | +/* | ||
5697 | + * Copyright (c) 2003-2007 Erez Zadok | ||
5698 | + * Copyright (c) 2003-2006 Charles P. Wright | ||
5699 | + * Copyright (c) 2005-2007 Josef 'Jeff' Sipek | ||
5700 | + * Copyright (c) 2005-2006 Junjiro Okajima | ||
5701 | + * Copyright (c) 2005 Arun M. Krishnakumar | ||
5702 | + * Copyright (c) 2004-2006 David P. Quigley | ||
5703 | + * Copyright (c) 2003-2004 Mohammad Nayyer Zubair | ||
5704 | + * Copyright (c) 2003 Puja Gupta | ||
5705 | + * Copyright (c) 2003 Harikesavan Krishnan | ||
5706 | + * Copyright (c) 2003-2007 Stony Brook University | ||
5707 | + * Copyright (c) 2003-2007 The Research Foundation of State University of New York | ||
5708 | + * | ||
5709 | + * This program is free software; you can redistribute it and/or modify | ||
5710 | + * it under the terms of the GNU General Public License version 2 as | ||
5711 | + * published by the Free Software Foundation. | ||
5712 | + */ | ||
5713 | + | ||
5714 | +#include "union.h" | ||
5715 | + | ||
5716 | +/* This file contains the routines for maintaining readdir state. */ | ||
5717 | + | ||
5718 | +/* There are two structures here, rdstate which is a hash table | ||
5719 | + * of the second structure which is a filldir_node. | ||
5720 | + */ | ||
5721 | + | ||
5722 | +/* This is a struct kmem_cache for filldir nodes, because we allocate a lot | ||
5723 | + * of them and they shouldn't waste memory. If the node has a small name | ||
5724 | + * (as defined by the dentry structure), then we use an inline name to | ||
5725 | + * preserve kmalloc space. | ||
5726 | + */ | ||
5727 | +static struct kmem_cache *unionfs_filldir_cachep; | ||
5728 | + | ||
5729 | +int unionfs_init_filldir_cache(void) | ||
5730 | +{ | ||
5731 | + unionfs_filldir_cachep = | ||
5732 | + kmem_cache_create("unionfs_filldir", sizeof(struct filldir_node), 0, | ||
5733 | + SLAB_RECLAIM_ACCOUNT, NULL, NULL); | ||
5734 | + | ||
5735 | + return (unionfs_filldir_cachep ? 0 : -ENOMEM); | ||
5736 | +} | ||
5737 | + | ||
5738 | +void unionfs_destroy_filldir_cache(void) | ||
5739 | +{ | ||
5740 | + if (unionfs_filldir_cachep) | ||
5741 | + kmem_cache_destroy(unionfs_filldir_cachep); | ||
5742 | +} | ||
5743 | + | ||
5744 | +/* This is a tuning parameter that tells us roughly how big to make the | ||
5745 | + * hash table in directory entries per page. This isn't perfect, but | ||
5746 | + * at least we get a hash table size that shouldn't be too overloaded. | ||
5747 | + * The following averages are based on my home directory. | ||
5748 | + * 14.44693 Overall | ||
5749 | + * 12.29 Single Page Directories | ||
5750 | + * 117.93 Multi-page directories | ||
5751 | + */ | ||
5752 | +#define DENTPAGE 4096 | ||
5753 | +#define DENTPERONEPAGE 12 | ||
5754 | +#define DENTPERPAGE 118 | ||
5755 | +#define MINHASHSIZE 1 | ||
5756 | +static int guesstimate_hash_size(struct inode *inode) | ||
5757 | +{ | ||
5758 | + struct inode *hidden_inode; | ||
5759 | + int bindex; | ||
5760 | + int hashsize = MINHASHSIZE; | ||
5761 | + | ||
5762 | + if (UNIONFS_I(inode)->hashsize > 0) | ||
5763 | + return UNIONFS_I(inode)->hashsize; | ||
5764 | + | ||
5765 | + for (bindex = ibstart(inode); bindex <= ibend(inode); bindex++) { | ||
5766 | + if (!(hidden_inode = unionfs_lower_inode_idx(inode, bindex))) | ||
5767 | + continue; | ||
5768 | + | ||
5769 | + if (hidden_inode->i_size == DENTPAGE) | ||
5770 | + hashsize += DENTPERONEPAGE; | ||
5771 | + else | ||
5772 | + hashsize += (hidden_inode->i_size / DENTPAGE) * DENTPERPAGE; | ||
5773 | + } | ||
5774 | + | ||
5775 | + return hashsize; | ||
5776 | +} | ||
5777 | + | ||
5778 | +int init_rdstate(struct file *file) | ||
5779 | +{ | ||
5780 | + BUG_ON(sizeof(loff_t) != (sizeof(unsigned int) + sizeof(unsigned int))); | ||
5781 | + BUG_ON(UNIONFS_F(file)->rdstate != NULL); | ||
5782 | + | ||
5783 | + UNIONFS_F(file)->rdstate = alloc_rdstate(file->f_dentry->d_inode, | ||
5784 | + fbstart(file)); | ||
5785 | + | ||
5786 | + return (UNIONFS_F(file)->rdstate ? 0 : -ENOMEM); | ||
5787 | +} | ||
5788 | + | ||
5789 | +struct unionfs_dir_state *find_rdstate(struct inode *inode, loff_t fpos) | ||
5790 | +{ | ||
5791 | + struct unionfs_dir_state *rdstate = NULL; | ||
5792 | + struct list_head *pos; | ||
5793 | + | ||
5794 | + spin_lock(&UNIONFS_I(inode)->rdlock); | ||
5795 | + list_for_each(pos, &UNIONFS_I(inode)->readdircache) { | ||
5796 | + struct unionfs_dir_state *r = | ||
5797 | + list_entry(pos, struct unionfs_dir_state, cache); | ||
5798 | + if (fpos == rdstate2offset(r)) { | ||
5799 | + UNIONFS_I(inode)->rdcount--; | ||
5800 | + list_del(&r->cache); | ||
5801 | + rdstate = r; | ||
5802 | + break; | ||
5803 | + } | ||
5804 | + } | ||
5805 | + spin_unlock(&UNIONFS_I(inode)->rdlock); | ||
5806 | + return rdstate; | ||
5807 | +} | ||
5808 | + | ||
5809 | +struct unionfs_dir_state *alloc_rdstate(struct inode *inode, int bindex) | ||
5810 | +{ | ||
5811 | + int i = 0; | ||
5812 | + int hashsize; | ||
5813 | + unsigned long mallocsize = sizeof(struct unionfs_dir_state); | ||
5814 | + struct unionfs_dir_state *rdstate; | ||
5815 | + | ||
5816 | + hashsize = guesstimate_hash_size(inode); | ||
5817 | + mallocsize += hashsize * sizeof(struct list_head); | ||
5818 | + mallocsize = __roundup_pow_of_two(mallocsize); | ||
5819 | + | ||
5820 | + /* This should give us about 500 entries anyway. */ | ||
5821 | + if (mallocsize > PAGE_SIZE) | ||
5822 | + mallocsize = PAGE_SIZE; | ||
5823 | + | ||
5824 | + hashsize = (mallocsize - | ||
5825 | + sizeof(struct unionfs_dir_state)) / sizeof(struct list_head); | ||
5826 | + | ||
5827 | + rdstate = kmalloc(mallocsize, GFP_KERNEL); | ||
5828 | + if (!rdstate) | ||
5829 | + return NULL; | ||
5830 | + | ||
5831 | + spin_lock(&UNIONFS_I(inode)->rdlock); | ||
5832 | + if (UNIONFS_I(inode)->cookie >= (MAXRDCOOKIE - 1)) | ||
5833 | + UNIONFS_I(inode)->cookie = 1; | ||
5834 | + else | ||
5835 | + UNIONFS_I(inode)->cookie++; | ||
5836 | + | ||
5837 | + rdstate->cookie = UNIONFS_I(inode)->cookie; | ||
5838 | + spin_unlock(&UNIONFS_I(inode)->rdlock); | ||
5839 | + rdstate->offset = 1; | ||
5840 | + rdstate->access = jiffies; | ||
5841 | + rdstate->bindex = bindex; | ||
5842 | + rdstate->dirpos = 0; | ||
5843 | + rdstate->hashentries = 0; | ||
5844 | + rdstate->size = hashsize; | ||
5845 | + for (i = 0; i < rdstate->size; i++) | ||
5846 | + INIT_LIST_HEAD(&rdstate->list[i]); | ||
5847 | + | ||
5848 | + return rdstate; | ||
5849 | +} | ||
5850 | + | ||
5851 | +static void free_filldir_node(struct filldir_node *node) | ||
5852 | +{ | ||
5853 | + if (node->namelen >= DNAME_INLINE_LEN_MIN) | ||
5854 | + kfree(node->name); | ||
5855 | + kmem_cache_free(unionfs_filldir_cachep, node); | ||
5856 | +} | ||
5857 | + | ||
5858 | +void free_rdstate(struct unionfs_dir_state *state) | ||
5859 | +{ | ||
5860 | + struct filldir_node *tmp; | ||
5861 | + int i; | ||
5862 | + | ||
5863 | + for (i = 0; i < state->size; i++) { | ||
5864 | + struct list_head *head = &(state->list[i]); | ||
5865 | + struct list_head *pos, *n; | ||
5866 | + | ||
5867 | + /* traverse the list and deallocate space */ | ||
5868 | + list_for_each_safe(pos, n, head) { | ||
5869 | + tmp = list_entry(pos, struct filldir_node, file_list); | ||
5870 | + list_del(&tmp->file_list); | ||
5871 | + free_filldir_node(tmp); | ||
5872 | + } | ||
5873 | + } | ||
5874 | + | ||
5875 | + kfree(state); | ||
5876 | +} | ||
5877 | + | ||
5878 | +struct filldir_node *find_filldir_node(struct unionfs_dir_state *rdstate, | ||
5879 | + const char *name, int namelen) | ||
5880 | +{ | ||
5881 | + int index; | ||
5882 | + unsigned int hash; | ||
5883 | + struct list_head *head; | ||
5884 | + struct list_head *pos; | ||
5885 | + struct filldir_node *cursor = NULL; | ||
5886 | + int found = 0; | ||
5887 | + | ||
5888 | + BUG_ON(namelen <= 0); | ||
5889 | + | ||
5890 | + hash = full_name_hash(name, namelen); | ||
5891 | + index = hash % rdstate->size; | ||
5892 | + | ||
5893 | + head = &(rdstate->list[index]); | ||
5894 | + list_for_each(pos, head) { | ||
5895 | + cursor = list_entry(pos, struct filldir_node, file_list); | ||
5896 | + | ||
5897 | + if (cursor->namelen == namelen && cursor->hash == hash && | ||
5898 | + !strncmp(cursor->name, name, namelen)) { | ||
5899 | + /* a duplicate exists, and hence no need to create | ||
5900 | + * entry to the list | ||
5901 | + */ | ||
5902 | + found = 1; | ||
5903 | + | ||
5904 | + /* if the duplicate is in this branch, then the file | ||
5905 | + * system is corrupted. | ||
5906 | + */ | ||
5907 | + if (cursor->bindex == rdstate->bindex) { | ||
5908 | + printk(KERN_DEBUG "Possible I/O error " | ||
5909 | + "unionfs_filldir: a file is duplicated " | ||
5910 | + "in the same branch %d: %s\n", | ||
5911 | + rdstate->bindex, cursor->name); | ||
5912 | + } | ||
5913 | + break; | ||
5914 | + } | ||
5915 | + } | ||
5916 | + | ||
5917 | + if (!found) | ||
5918 | + cursor = NULL; | ||
5919 | + | ||
5920 | + return cursor; | ||
5921 | +} | ||
5922 | + | ||
5923 | +int add_filldir_node(struct unionfs_dir_state *rdstate, const char *name, | ||
5924 | + int namelen, int bindex, int whiteout) | ||
5925 | +{ | ||
5926 | + struct filldir_node *new; | ||
5927 | + unsigned int hash; | ||
5928 | + int index; | ||
5929 | + int err = 0; | ||
5930 | + struct list_head *head; | ||
5931 | + | ||
5932 | + BUG_ON(namelen <= 0); | ||
5933 | + | ||
5934 | + hash = full_name_hash(name, namelen); | ||
5935 | + index = hash % rdstate->size; | ||
5936 | + head = &(rdstate->list[index]); | ||
5937 | + | ||
5938 | + new = kmem_cache_alloc(unionfs_filldir_cachep, GFP_KERNEL); | ||
5939 | + if (!new) { | ||
5940 | + err = -ENOMEM; | ||
5941 | + goto out; | ||
5942 | + } | ||
5943 | + | ||
5944 | + INIT_LIST_HEAD(&new->file_list); | ||
5945 | + new->namelen = namelen; | ||
5946 | + new->hash = hash; | ||
5947 | + new->bindex = bindex; | ||
5948 | + new->whiteout = whiteout; | ||
5949 | + | ||
5950 | + if (namelen < DNAME_INLINE_LEN_MIN) | ||
5951 | + new->name = new->iname; | ||
5952 | + else { | ||
5953 | + new->name = kmalloc(namelen + 1, GFP_KERNEL); | ||
5954 | + if (!new->name) { | ||
5955 | + kmem_cache_free(unionfs_filldir_cachep, new); | ||
5956 | + new = NULL; | ||
5957 | + goto out; | ||
5958 | + } | ||
5959 | + } | ||
5960 | + | ||
5961 | + memcpy(new->name, name, namelen); | ||
5962 | + new->name[namelen] = '\0'; | ||
5963 | + | ||
5964 | + rdstate->hashentries++; | ||
5965 | + | ||
5966 | + list_add(&(new->file_list), head); | ||
5967 | +out: | ||
5968 | + return err; | ||
5969 | +} | ||
5970 | + | ||
5971 | diff --git a/fs/unionfs/rename.c b/fs/unionfs/rename.c | ||
5972 | new file mode 100644 | ||
5973 | index 0000000..0044492 | ||
5974 | --- /dev/null | ||
5975 | +++ b/fs/unionfs/rename.c | ||
5976 | @@ -0,0 +1,448 @@ | ||
5977 | +/* | ||
5978 | + * Copyright (c) 2003-2007 Erez Zadok | ||
5979 | + * Copyright (c) 2003-2006 Charles P. Wright | ||
5980 | + * Copyright (c) 2005-2007 Josef 'Jeff' Sipek | ||
5981 | + * Copyright (c) 2005-2006 Junjiro Okajima | ||
5982 | + * Copyright (c) 2005 Arun M. Krishnakumar | ||
5983 | + * Copyright (c) 2004-2006 David P. Quigley | ||
5984 | + * Copyright (c) 2003-2004 Mohammad Nayyer Zubair | ||
5985 | + * Copyright (c) 2003 Puja Gupta | ||
5986 | + * Copyright (c) 2003 Harikesavan Krishnan | ||
5987 | + * Copyright (c) 2003-2007 Stony Brook University | ||
5988 | + * Copyright (c) 2003-2007 The Research Foundation of State University of New York | ||
5989 | + * | ||
5990 | + * This program is free software; you can redistribute it and/or modify | ||
5991 | + * it under the terms of the GNU General Public License version 2 as | ||
5992 | + * published by the Free Software Foundation. | ||
5993 | + */ | ||
5994 | + | ||
5995 | +#include "union.h" | ||
5996 | + | ||
5997 | +static int do_rename(struct inode *old_dir, struct dentry *old_dentry, | ||
5998 | + struct inode *new_dir, struct dentry *new_dentry, | ||
5999 | + int bindex, struct dentry **wh_old) | ||
6000 | +{ | ||
6001 | + int err = 0; | ||
6002 | + struct dentry *hidden_old_dentry; | ||
6003 | + struct dentry *hidden_new_dentry; | ||
6004 | + struct dentry *hidden_old_dir_dentry; | ||
6005 | + struct dentry *hidden_new_dir_dentry; | ||
6006 | + struct dentry *hidden_wh_dentry; | ||
6007 | + struct dentry *hidden_wh_dir_dentry; | ||
6008 | + char *wh_name = NULL; | ||
6009 | + | ||
6010 | + hidden_new_dentry = unionfs_lower_dentry_idx(new_dentry, bindex); | ||
6011 | + hidden_old_dentry = unionfs_lower_dentry_idx(old_dentry, bindex); | ||
6012 | + | ||
6013 | + if (!hidden_new_dentry) { | ||
6014 | + hidden_new_dentry = | ||
6015 | + create_parents(new_dentry->d_parent->d_inode, new_dentry, bindex); | ||
6016 | + if (IS_ERR(hidden_new_dentry)) { | ||
6017 | + printk(KERN_DEBUG "error creating directory tree for" | ||
6018 | + " rename, bindex = %d, err = %ld\n", | ||
6019 | + bindex, PTR_ERR(hidden_new_dentry)); | ||
6020 | + err = PTR_ERR(hidden_new_dentry); | ||
6021 | + goto out; | ||
6022 | + } | ||
6023 | + } | ||
6024 | + | ||
6025 | + wh_name = alloc_whname(new_dentry->d_name.name, new_dentry->d_name.len); | ||
6026 | + if (IS_ERR(wh_name)) { | ||
6027 | + err = PTR_ERR(wh_name); | ||
6028 | + goto out; | ||
6029 | + } | ||
6030 | + | ||
6031 | + hidden_wh_dentry = lookup_one_len(wh_name, hidden_new_dentry->d_parent, | ||
6032 | + new_dentry->d_name.len + UNIONFS_WHLEN); | ||
6033 | + if (IS_ERR(hidden_wh_dentry)) { | ||
6034 | + err = PTR_ERR(hidden_wh_dentry); | ||
6035 | + goto out; | ||
6036 | + } | ||
6037 | + | ||
6038 | + if (hidden_wh_dentry->d_inode) { | ||
6039 | + /* get rid of the whiteout that is existing */ | ||
6040 | + if (hidden_new_dentry->d_inode) { | ||
6041 | + printk(KERN_WARNING "Both a whiteout and a dentry" | ||
6042 | + " exist when doing a rename!\n"); | ||
6043 | + err = -EIO; | ||
6044 | + | ||
6045 | + dput(hidden_wh_dentry); | ||
6046 | + goto out; | ||
6047 | + } | ||
6048 | + | ||
6049 | + hidden_wh_dir_dentry = lock_parent(hidden_wh_dentry); | ||
6050 | + if (!(err = is_robranch_super(old_dentry->d_sb, bindex))) | ||
6051 | + err = vfs_unlink(hidden_wh_dir_dentry->d_inode, | ||
6052 | + hidden_wh_dentry); | ||
6053 | + | ||
6054 | + dput(hidden_wh_dentry); | ||
6055 | + unlock_dir(hidden_wh_dir_dentry); | ||
6056 | + if (err) | ||
6057 | + goto out; | ||
6058 | + } else | ||
6059 | + dput(hidden_wh_dentry); | ||
6060 | + | ||
6061 | + dget(hidden_old_dentry); | ||
6062 | + hidden_old_dir_dentry = dget_parent(hidden_old_dentry); | ||
6063 | + hidden_new_dir_dentry = dget_parent(hidden_new_dentry); | ||
6064 | + | ||
6065 | + lock_rename(hidden_old_dir_dentry, hidden_new_dir_dentry); | ||
6066 | + | ||
6067 | + err = is_robranch_super(old_dentry->d_sb, bindex); | ||
6068 | + if (err) | ||
6069 | + goto out_unlock; | ||
6070 | + | ||
6071 | + /* ready to whiteout for old_dentry. caller will create the actual | ||
6072 | + * whiteout, and must dput(*wh_old) | ||
6073 | + */ | ||
6074 | + if (wh_old) { | ||
6075 | + char *whname; | ||
6076 | + whname = alloc_whname(old_dentry->d_name.name, | ||
6077 | + old_dentry->d_name.len); | ||
6078 | + err = PTR_ERR(whname); | ||
6079 | + if (IS_ERR(whname)) | ||
6080 | + goto out_unlock; | ||
6081 | + *wh_old = lookup_one_len(whname, hidden_old_dir_dentry, | ||
6082 | + old_dentry->d_name.len + UNIONFS_WHLEN); | ||
6083 | + kfree(whname); | ||
6084 | + err = PTR_ERR(*wh_old); | ||
6085 | + if (IS_ERR(*wh_old)) { | ||
6086 | + *wh_old = NULL; | ||
6087 | + goto out_unlock; | ||
6088 | + } | ||
6089 | + } | ||
6090 | + | ||
6091 | + err = vfs_rename(hidden_old_dir_dentry->d_inode, hidden_old_dentry, | ||
6092 | + hidden_new_dir_dentry->d_inode, hidden_new_dentry); | ||
6093 | + | ||
6094 | +out_unlock: | ||
6095 | + unlock_rename(hidden_old_dir_dentry, hidden_new_dir_dentry); | ||
6096 | + | ||
6097 | + dput(hidden_old_dir_dentry); | ||
6098 | + dput(hidden_new_dir_dentry); | ||
6099 | + dput(hidden_old_dentry); | ||
6100 | + | ||
6101 | +out: | ||
6102 | + if (!err) { | ||
6103 | + /* Fixup the newdentry. */ | ||
6104 | + if (bindex < dbstart(new_dentry)) | ||
6105 | + set_dbstart(new_dentry, bindex); | ||
6106 | + else if (bindex > dbend(new_dentry)) | ||
6107 | + set_dbend(new_dentry, bindex); | ||
6108 | + } | ||
6109 | + | ||
6110 | + kfree(wh_name); | ||
6111 | + | ||
6112 | + return err; | ||
6113 | +} | ||
6114 | + | ||
6115 | +static int do_unionfs_rename(struct inode *old_dir, | ||
6116 | + struct dentry *old_dentry, | ||
6117 | + struct inode *new_dir, | ||
6118 | + struct dentry *new_dentry) | ||
6119 | +{ | ||
6120 | + int err = 0; | ||
6121 | + int bindex, bwh_old; | ||
6122 | + int old_bstart, old_bend; | ||
6123 | + int new_bstart, new_bend; | ||
6124 | + int do_copyup = -1; | ||
6125 | + struct dentry *parent_dentry; | ||
6126 | + int local_err = 0; | ||
6127 | + int eio = 0; | ||
6128 | + int revert = 0; | ||
6129 | + struct dentry *wh_old = NULL; | ||
6130 | + | ||
6131 | + old_bstart = dbstart(old_dentry); | ||
6132 | + bwh_old = old_bstart; | ||
6133 | + old_bend = dbend(old_dentry); | ||
6134 | + parent_dentry = old_dentry->d_parent; | ||
6135 | + | ||
6136 | + new_bstart = dbstart(new_dentry); | ||
6137 | + new_bend = dbend(new_dentry); | ||
6138 | + | ||
6139 | + /* Rename source to destination. */ | ||
6140 | + err = do_rename(old_dir, old_dentry, new_dir, new_dentry, old_bstart, | ||
6141 | + &wh_old); | ||
6142 | + if (err) { | ||
6143 | + if (!IS_COPYUP_ERR(err)) | ||
6144 | + goto out; | ||
6145 | + do_copyup = old_bstart - 1; | ||
6146 | + } else | ||
6147 | + revert = 1; | ||
6148 | + | ||
6149 | + /* Unlink all instances of destination that exist to the left of | ||
6150 | + * bstart of source. On error, revert back, goto out. | ||
6151 | + */ | ||
6152 | + for (bindex = old_bstart - 1; bindex >= new_bstart; bindex--) { | ||
6153 | + struct dentry *unlink_dentry; | ||
6154 | + struct dentry *unlink_dir_dentry; | ||
6155 | + | ||
6156 | + unlink_dentry = unionfs_lower_dentry_idx(new_dentry, bindex); | ||
6157 | + if (!unlink_dentry) | ||
6158 | + continue; | ||
6159 | + | ||
6160 | + unlink_dir_dentry = lock_parent(unlink_dentry); | ||
6161 | + if (!(err = is_robranch_super(old_dir->i_sb, bindex))) | ||
6162 | + err = vfs_unlink(unlink_dir_dentry->d_inode, | ||
6163 | + unlink_dentry); | ||
6164 | + | ||
6165 | + fsstack_copy_attr_times(new_dentry->d_parent->d_inode, | ||
6166 | + unlink_dir_dentry->d_inode); | ||
6167 | + /* propagate number of hard-links */ | ||
6168 | + new_dentry->d_parent->d_inode->i_nlink = | ||
6169 | + unionfs_get_nlinks(new_dentry->d_parent->d_inode); | ||
6170 | + | ||
6171 | + unlock_dir(unlink_dir_dentry); | ||
6172 | + if (!err) { | ||
6173 | + if (bindex != new_bstart) { | ||
6174 | + dput(unlink_dentry); | ||
6175 | + unionfs_set_lower_dentry_idx(new_dentry, bindex, NULL); | ||
6176 | + } | ||
6177 | + } else if (IS_COPYUP_ERR(err)) { | ||
6178 | + do_copyup = bindex - 1; | ||
6179 | + } else if (revert) { | ||
6180 | + dput(wh_old); | ||
6181 | + goto revert; | ||
6182 | + } | ||
6183 | + } | ||
6184 | + | ||
6185 | + if (do_copyup != -1) { | ||
6186 | + for (bindex = do_copyup; bindex >= 0; bindex--) { | ||
6187 | + /* copyup the file into some left directory, so that | ||
6188 | + * you can rename it | ||
6189 | + */ | ||
6190 | + err = copyup_dentry(old_dentry->d_parent->d_inode, | ||
6191 | + old_dentry, old_bstart, bindex, NULL, | ||
6192 | + old_dentry->d_inode->i_size); | ||
6193 | + if (!err) { | ||
6194 | + dput(wh_old); | ||
6195 | + bwh_old = bindex; | ||
6196 | + err = do_rename(old_dir, old_dentry, new_dir, | ||
6197 | + new_dentry, bindex, &wh_old); | ||
6198 | + break; | ||
6199 | + } | ||
6200 | + } | ||
6201 | + } | ||
6202 | + | ||
6203 | + /* make it opaque */ | ||
6204 | + if (S_ISDIR(old_dentry->d_inode->i_mode)) { | ||
6205 | + err = make_dir_opaque(old_dentry, dbstart(old_dentry)); | ||
6206 | + if (err) | ||
6207 | + goto revert; | ||
6208 | + } | ||
6209 | + | ||
6210 | + /* Create whiteout for source, only if: | ||
6211 | + * (1) There is more than one underlying instance of source. | ||
6212 | + * (2) We did a copy_up | ||
6213 | + */ | ||
6214 | + if ((old_bstart != old_bend) || (do_copyup != -1)) { | ||
6215 | + struct dentry *hidden_parent; | ||
6216 | + BUG_ON(!wh_old || wh_old->d_inode || bwh_old < 0); | ||
6217 | + hidden_parent = lock_parent(wh_old); | ||
6218 | + local_err = vfs_create(hidden_parent->d_inode, wh_old, S_IRUGO, | ||
6219 | + NULL); | ||
6220 | + unlock_dir(hidden_parent); | ||
6221 | + if (!local_err) | ||
6222 | + set_dbopaque(old_dentry, bwh_old); | ||
6223 | + else { | ||
6224 | + /* We can't fix anything now, so we cop-out and use -EIO. */ | ||
6225 | + printk(KERN_ERR "We can't create a whiteout for the " | ||
6226 | + "source in rename!\n"); | ||
6227 | + err = -EIO; | ||
6228 | + } | ||
6229 | + } | ||
6230 | + | ||
6231 | +out: | ||
6232 | + dput(wh_old); | ||
6233 | + return err; | ||
6234 | + | ||
6235 | +revert: | ||
6236 | + /* Do revert here. */ | ||
6237 | + local_err = unionfs_refresh_hidden_dentry(new_dentry, old_bstart); | ||
6238 | + if (local_err) { | ||
6239 | + printk(KERN_WARNING "Revert failed in rename: the new refresh " | ||
6240 | + "failed.\n"); | ||
6241 | + eio = -EIO; | ||
6242 | + } | ||
6243 | + | ||
6244 | + local_err = unionfs_refresh_hidden_dentry(old_dentry, old_bstart); | ||
6245 | + if (local_err) { | ||
6246 | + printk(KERN_WARNING "Revert failed in rename: the old refresh " | ||
6247 | + "failed.\n"); | ||
6248 | + eio = -EIO; | ||
6249 | + goto revert_out; | ||
6250 | + } | ||
6251 | + | ||
6252 | + if (!unionfs_lower_dentry_idx(new_dentry, bindex) || | ||
6253 | + !unionfs_lower_dentry_idx(new_dentry, bindex)->d_inode) { | ||
6254 | + printk(KERN_WARNING "Revert failed in rename: the object " | ||
6255 | + "disappeared from under us!\n"); | ||
6256 | + eio = -EIO; | ||
6257 | + goto revert_out; | ||
6258 | + } | ||
6259 | + | ||
6260 | + if (unionfs_lower_dentry_idx(old_dentry, bindex) && | ||
6261 | + unionfs_lower_dentry_idx(old_dentry, bindex)->d_inode) { | ||
6262 | + printk(KERN_WARNING "Revert failed in rename: the object was " | ||
6263 | + "created underneath us!\n"); | ||
6264 | + eio = -EIO; | ||
6265 | + goto revert_out; | ||
6266 | + } | ||
6267 | + | ||
6268 | + local_err = do_rename(new_dir, new_dentry, old_dir, old_dentry, old_bstart, | ||
6269 | + NULL); | ||
6270 | + | ||
6271 | + /* If we can't fix it, then we cop-out with -EIO. */ | ||
6272 | + if (local_err) { | ||
6273 | + printk(KERN_WARNING "Revert failed in rename!\n"); | ||
6274 | + eio = -EIO; | ||
6275 | + } | ||
6276 | + | ||
6277 | + local_err = unionfs_refresh_hidden_dentry(new_dentry, bindex); | ||
6278 | + if (local_err) | ||
6279 | + eio = -EIO; | ||
6280 | + local_err = unionfs_refresh_hidden_dentry(old_dentry, bindex); | ||
6281 | + if (local_err) | ||
6282 | + eio = -EIO; | ||
6283 | + | ||
6284 | +revert_out: | ||
6285 | + if (eio) | ||
6286 | + err = eio; | ||
6287 | + return err; | ||
6288 | +} | ||
6289 | + | ||
6290 | +static struct dentry *lookup_whiteout(struct dentry *dentry) | ||
6291 | +{ | ||
6292 | + char *whname; | ||
6293 | + int bindex = -1, bstart = -1, bend = -1; | ||
6294 | + struct dentry *parent, *hidden_parent, *wh_dentry; | ||
6295 | + | ||
6296 | + whname = alloc_whname(dentry->d_name.name, dentry->d_name.len); | ||
6297 | + if (IS_ERR(whname)) | ||
6298 | + return (void *)whname; | ||
6299 | + | ||
6300 | + parent = dget_parent(dentry); | ||
6301 | + unionfs_lock_dentry(parent); | ||
6302 | + bstart = dbstart(parent); | ||
6303 | + bend = dbend(parent); | ||
6304 | + wh_dentry = ERR_PTR(-ENOENT); | ||
6305 | + for (bindex = bstart; bindex <= bend; bindex++) { | ||
6306 | + hidden_parent = unionfs_lower_dentry_idx(parent, bindex); | ||
6307 | + if (!hidden_parent) | ||
6308 | + continue; | ||
6309 | + wh_dentry = lookup_one_len(whname, hidden_parent, | ||
6310 | + dentry->d_name.len + UNIONFS_WHLEN); | ||
6311 | + if (IS_ERR(wh_dentry)) | ||
6312 | + continue; | ||
6313 | + if (wh_dentry->d_inode) | ||
6314 | + break; | ||
6315 | + dput(wh_dentry); | ||
6316 | + wh_dentry = ERR_PTR(-ENOENT); | ||
6317 | + } | ||
6318 | + unionfs_unlock_dentry(parent); | ||
6319 | + dput(parent); | ||
6320 | + kfree(whname); | ||
6321 | + return wh_dentry; | ||
6322 | +} | ||
6323 | + | ||
6324 | +/* We can't copyup a directory, because it may involve huge | ||
6325 | + * numbers of children, etc. Doing that in the kernel would | ||
6326 | + * be bad, so instead we let the userspace recurse and ask us | ||
6327 | + * to copy up each file separately | ||
6328 | + */ | ||
6329 | +static int may_rename_dir(struct dentry *dentry) | ||
6330 | +{ | ||
6331 | + int err, bstart; | ||
6332 | + | ||
6333 | + err = check_empty(dentry, NULL); | ||
6334 | + if (err == -ENOTEMPTY) { | ||
6335 | + if (is_robranch(dentry)) | ||
6336 | + return -EXDEV; | ||
6337 | + } else if (err) | ||
6338 | + return err; | ||
6339 | + | ||
6340 | + bstart = dbstart(dentry); | ||
6341 | + if (dbend(dentry) == bstart || dbopaque(dentry) == bstart) | ||
6342 | + return 0; | ||
6343 | + | ||
6344 | + set_dbstart(dentry, bstart + 1); | ||
6345 | + err = check_empty(dentry, NULL); | ||
6346 | + set_dbstart(dentry, bstart); | ||
6347 | + if (err == -ENOTEMPTY) | ||
6348 | + err = -EXDEV; | ||
6349 | + return err; | ||
6350 | +} | ||
6351 | + | ||
6352 | +int unionfs_rename(struct inode *old_dir, struct dentry *old_dentry, | ||
6353 | + struct inode *new_dir, struct dentry *new_dentry) | ||
6354 | +{ | ||
6355 | + int err = 0; | ||
6356 | + struct dentry *wh_dentry; | ||
6357 | + | ||
6358 | + BUG_ON(!is_valid_dentry(old_dentry)); | ||
6359 | + BUG_ON(!is_valid_dentry(new_dentry)); | ||
6360 | + | ||
6361 | + double_lock_dentry(old_dentry, new_dentry); | ||
6362 | + | ||
6363 | + if (!S_ISDIR(old_dentry->d_inode->i_mode)) | ||
6364 | + err = unionfs_partial_lookup(old_dentry); | ||
6365 | + else | ||
6366 | + err = may_rename_dir(old_dentry); | ||
6367 | + | ||
6368 | + if (err) | ||
6369 | + goto out; | ||
6370 | + | ||
6371 | + err = unionfs_partial_lookup(new_dentry); | ||
6372 | + if (err) | ||
6373 | + goto out; | ||
6374 | + | ||
6375 | + /* | ||
6376 | + * if new_dentry is already hidden because of whiteout, | ||
6377 | + * simply override it even if the whiteouted dir is not empty. | ||
6378 | + */ | ||
6379 | + wh_dentry = lookup_whiteout(new_dentry); | ||
6380 | + if (!IS_ERR(wh_dentry)) | ||
6381 | + dput(wh_dentry); | ||
6382 | + else if (new_dentry->d_inode) { | ||
6383 | + if (S_ISDIR(old_dentry->d_inode->i_mode) != | ||
6384 | + S_ISDIR(new_dentry->d_inode->i_mode)) { | ||
6385 | + err = S_ISDIR(old_dentry->d_inode->i_mode) ? | ||
6386 | + -ENOTDIR : -EISDIR; | ||
6387 | + goto out; | ||
6388 | + } | ||
6389 | + | ||
6390 | + if (S_ISDIR(new_dentry->d_inode->i_mode)) { | ||
6391 | + struct unionfs_dir_state *namelist; | ||
6392 | + /* check if this unionfs directory is empty or not */ | ||
6393 | + err = check_empty(new_dentry, &namelist); | ||
6394 | + if (err) | ||
6395 | + goto out; | ||
6396 | + | ||
6397 | + if (!is_robranch(new_dentry)) | ||
6398 | + err = delete_whiteouts(new_dentry, | ||
6399 | + dbstart(new_dentry), | ||
6400 | + namelist); | ||
6401 | + | ||
6402 | + free_rdstate(namelist); | ||
6403 | + | ||
6404 | + if (err) | ||
6405 | + goto out; | ||
6406 | + } | ||
6407 | + } | ||
6408 | + err = do_unionfs_rename(old_dir, old_dentry, new_dir, new_dentry); | ||
6409 | + | ||
6410 | +out: | ||
6411 | + if (err) | ||
6412 | + /* clear the new_dentry stuff created */ | ||
6413 | + d_drop(new_dentry); | ||
6414 | + else | ||
6415 | + /* force re-lookup since the dir on ro branch is not renamed, | ||
6416 | + and hidden dentries still indicate the un-renamed ones. */ | ||
6417 | + if (S_ISDIR(old_dentry->d_inode->i_mode)) | ||
6418 | + atomic_dec(&UNIONFS_D(old_dentry)->generation); | ||
6419 | + | ||
6420 | + unionfs_unlock_dentry(new_dentry); | ||
6421 | + unionfs_unlock_dentry(old_dentry); | ||
6422 | + return err; | ||
6423 | +} | ||
6424 | + | ||
6425 | diff --git a/fs/unionfs/sioq.c b/fs/unionfs/sioq.c | ||
6426 | new file mode 100644 | ||
6427 | index 0000000..c0d89a3 | ||
6428 | --- /dev/null | ||
6429 | +++ b/fs/unionfs/sioq.c | ||
6430 | @@ -0,0 +1,123 @@ | ||
6431 | +/* | ||
6432 | + * Copyright (c) 2003-2007 Erez Zadok | ||
6433 | + * Copyright (c) 2003-2006 Charles P. Wright | ||
6434 | + * Copyright (c) 2005-2007 Josef 'Jeff' Sipek | ||
6435 | + * Copyright (c) 2005-2006 Junjiro Okajima | ||
6436 | + * Copyright (c) 2005 Arun M. Krishnakumar | ||
6437 | + * Copyright (c) 2004-2006 David P. Quigley | ||
6438 | + * Copyright (c) 2003-2004 Mohammad Nayyer Zubair | ||
6439 | + * Copyright (c) 2003 Puja Gupta | ||
6440 | + * Copyright (c) 2003 Harikesavan Krishnan | ||
6441 | + * Copyright (c) 2003-2007 Stony Brook University | ||
6442 | + * Copyright (c) 2003-2007 The Research Foundation of State University of New York | ||
6443 | + * | ||
6444 | + * This program is free software; you can redistribute it and/or modify | ||
6445 | + * it under the terms of the GNU General Public License version 2 as | ||
6446 | + * published by the Free Software Foundation. | ||
6447 | + */ | ||
6448 | + | ||
6449 | +#include "union.h" | ||
6450 | + | ||
6451 | +/* Super-user IO work Queue - sometimes we need to perform actions which | ||
6452 | + * would fail due to the unix permissions on the parent directory (e.g., | ||
6453 | + * rmdir a directory which appears empty, but in reality contains | ||
6454 | + * whiteouts). | ||
6455 | + */ | ||
6456 | + | ||
6457 | +static struct workqueue_struct *superio_workqueue; | ||
6458 | + | ||
6459 | +int __init init_sioq(void) | ||
6460 | +{ | ||
6461 | + int err; | ||
6462 | + | ||
6463 | + superio_workqueue = create_workqueue("unionfs_siod"); | ||
6464 | + if (!IS_ERR(superio_workqueue)) | ||
6465 | + return 0; | ||
6466 | + | ||
6467 | + err = PTR_ERR(superio_workqueue); | ||
6468 | + printk(KERN_ERR "create_workqueue failed %d\n", err); | ||
6469 | + superio_workqueue = NULL; | ||
6470 | + return err; | ||
6471 | +} | ||
6472 | + | ||
6473 | +void stop_sioq(void) | ||
6474 | +{ | ||
6475 | + if (superio_workqueue) | ||
6476 | + destroy_workqueue(superio_workqueue); | ||
6477 | +} | ||
6478 | + | ||
6479 | +void run_sioq(work_func_t func, struct sioq_args *args) | ||
6480 | +{ | ||
6481 | + INIT_WORK(&args->work, func); | ||
6482 | + | ||
6483 | + init_completion(&args->comp); | ||
6484 | + while (!queue_work(superio_workqueue, &args->work)) { | ||
6485 | + /* TODO: do accounting if needed */ | ||
6486 | + schedule(); | ||
6487 | + } | ||
6488 | + wait_for_completion(&args->comp); | ||
6489 | +} | ||
6490 | + | ||
6491 | +void __unionfs_create(struct work_struct *work) | ||
6492 | +{ | ||
6493 | + struct sioq_args *args = container_of(work, struct sioq_args, work); | ||
6494 | + struct create_args *c = &args->create; | ||
6495 | + | ||
6496 | + args->err = vfs_create(c->parent, c->dentry, c->mode, c->nd); | ||
6497 | + complete(&args->comp); | ||
6498 | +} | ||
6499 | + | ||
6500 | +void __unionfs_mkdir(struct work_struct *work) | ||
6501 | +{ | ||
6502 | + struct sioq_args *args = container_of(work, struct sioq_args, work); | ||
6503 | + struct mkdir_args *m = &args->mkdir; | ||
6504 | + | ||
6505 | + args->err = vfs_mkdir(m->parent, m->dentry, m->mode); | ||
6506 | + complete(&args->comp); | ||
6507 | +} | ||
6508 | + | ||
6509 | +void __unionfs_mknod(struct work_struct *work) | ||
6510 | +{ | ||
6511 | + struct sioq_args *args = container_of(work, struct sioq_args, work); | ||
6512 | + struct mknod_args *m = &args->mknod; | ||
6513 | + | ||
6514 | + args->err = vfs_mknod(m->parent, m->dentry, m->mode, m->dev); | ||
6515 | + complete(&args->comp); | ||
6516 | +} | ||
6517 | + | ||
6518 | +void __unionfs_symlink(struct work_struct *work) | ||
6519 | +{ | ||
6520 | + struct sioq_args *args = container_of(work, struct sioq_args, work); | ||
6521 | + struct symlink_args *s = &args->symlink; | ||
6522 | + | ||
6523 | + args->err = vfs_symlink(s->parent, s->dentry, s->symbuf, s->mode); | ||
6524 | + complete(&args->comp); | ||
6525 | +} | ||
6526 | + | ||
6527 | +void __unionfs_unlink(struct work_struct *work) | ||
6528 | +{ | ||
6529 | + struct sioq_args *args = container_of(work, struct sioq_args, work); | ||
6530 | + struct unlink_args *u = &args->unlink; | ||
6531 | + | ||
6532 | + args->err = vfs_unlink(u->parent, u->dentry); | ||
6533 | + complete(&args->comp); | ||
6534 | +} | ||
6535 | + | ||
6536 | +void __delete_whiteouts(struct work_struct *work) | ||
6537 | +{ | ||
6538 | + struct sioq_args *args = container_of(work, struct sioq_args, work); | ||
6539 | + struct deletewh_args *d = &args->deletewh; | ||
6540 | + | ||
6541 | + args->err = do_delete_whiteouts(d->dentry, d->bindex, d->namelist); | ||
6542 | + complete(&args->comp); | ||
6543 | +} | ||
6544 | + | ||
6545 | +void __is_opaque_dir(struct work_struct *work) | ||
6546 | +{ | ||
6547 | + struct sioq_args *args = container_of(work, struct sioq_args, work); | ||
6548 | + | ||
6549 | + args->ret = lookup_one_len(UNIONFS_DIR_OPAQUE, args->is_opaque.dentry, | ||
6550 | + sizeof(UNIONFS_DIR_OPAQUE) - 1); | ||
6551 | + complete(&args->comp); | ||
6552 | +} | ||
6553 | + | ||
6554 | diff --git a/fs/unionfs/sioq.h b/fs/unionfs/sioq.h | ||
6555 | new file mode 100644 | ||
6556 | index 0000000..20e3b0c | ||
6557 | --- /dev/null | ||
6558 | +++ b/fs/unionfs/sioq.h | ||
6559 | @@ -0,0 +1,78 @@ | ||
6560 | +#ifndef _SIOQ_H | ||
6561 | +#define _SIOQ_H | ||
6562 | + | ||
6563 | +struct deletewh_args { | ||
6564 | + struct unionfs_dir_state *namelist; | ||
6565 | + struct dentry *dentry; | ||
6566 | + int bindex; | ||
6567 | +}; | ||
6568 | + | ||
6569 | +struct is_opaque_args { | ||
6570 | + struct dentry *dentry; | ||
6571 | +}; | ||
6572 | + | ||
6573 | +struct create_args { | ||
6574 | + struct inode *parent; | ||
6575 | + struct dentry *dentry; | ||
6576 | + umode_t mode; | ||
6577 | + struct nameidata *nd; | ||
6578 | +}; | ||
6579 | + | ||
6580 | +struct mkdir_args { | ||
6581 | + struct inode *parent; | ||
6582 | + struct dentry *dentry; | ||
6583 | + umode_t mode; | ||
6584 | +}; | ||
6585 | + | ||
6586 | +struct mknod_args { | ||
6587 | + struct inode *parent; | ||
6588 | + struct dentry *dentry; | ||
6589 | + umode_t mode; | ||
6590 | + dev_t dev; | ||
6591 | +}; | ||
6592 | + | ||
6593 | +struct symlink_args { | ||
6594 | + struct inode *parent; | ||
6595 | + struct dentry *dentry; | ||
6596 | + char *symbuf; | ||
6597 | + umode_t mode; | ||
6598 | +}; | ||
6599 | + | ||
6600 | +struct unlink_args { | ||
6601 | + struct inode *parent; | ||
6602 | + struct dentry *dentry; | ||
6603 | +}; | ||
6604 | + | ||
6605 | + | ||
6606 | +struct sioq_args { | ||
6607 | + struct completion comp; | ||
6608 | + struct work_struct work; | ||
6609 | + int err; | ||
6610 | + void *ret; | ||
6611 | + | ||
6612 | + union { | ||
6613 | + struct deletewh_args deletewh; | ||
6614 | + struct is_opaque_args is_opaque; | ||
6615 | + struct create_args create; | ||
6616 | + struct mkdir_args mkdir; | ||
6617 | + struct mknod_args mknod; | ||
6618 | + struct symlink_args symlink; | ||
6619 | + struct unlink_args unlink; | ||
6620 | + }; | ||
6621 | +}; | ||
6622 | + | ||
6623 | +extern int __init init_sioq(void); | ||
6624 | +extern __exit void stop_sioq(void); | ||
6625 | +extern void run_sioq(work_func_t func, struct sioq_args *args); | ||
6626 | + | ||
6627 | +/* Extern definitions for our privlege escalation helpers */ | ||
6628 | +extern void __unionfs_create(struct work_struct *work); | ||
6629 | +extern void __unionfs_mkdir(struct work_struct *work); | ||
6630 | +extern void __unionfs_mknod(struct work_struct *work); | ||
6631 | +extern void __unionfs_symlink(struct work_struct *work); | ||
6632 | +extern void __unionfs_unlink(struct work_struct *work); | ||
6633 | +extern void __delete_whiteouts(struct work_struct *work); | ||
6634 | +extern void __is_opaque_dir(struct work_struct *work); | ||
6635 | + | ||
6636 | +#endif /* _SIOQ_H */ | ||
6637 | + | ||
6638 | diff --git a/fs/unionfs/subr.c b/fs/unionfs/subr.c | ||
6639 | new file mode 100644 | ||
6640 | index 0000000..d274752 | ||
6641 | --- /dev/null | ||
6642 | +++ b/fs/unionfs/subr.c | ||
6643 | @@ -0,0 +1,233 @@ | ||
6644 | +/* | ||
6645 | + * Copyright (c) 2003-2007 Erez Zadok | ||
6646 | + * Copyright (c) 2003-2006 Charles P. Wright | ||
6647 | + * Copyright (c) 2005-2007 Josef 'Jeff' Sipek | ||
6648 | + * Copyright (c) 2005-2006 Junjiro Okajima | ||
6649 | + * Copyright (c) 2005 Arun M. Krishnakumar | ||
6650 | + * Copyright (c) 2004-2006 David P. Quigley | ||
6651 | + * Copyright (c) 2003-2004 Mohammad Nayyer Zubair | ||
6652 | + * Copyright (c) 2003 Puja Gupta | ||
6653 | + * Copyright (c) 2003 Harikesavan Krishnan | ||
6654 | + * Copyright (c) 2003-2007 Stony Brook University | ||
6655 | + * Copyright (c) 2003-2007 The Research Foundation of State University of New York | ||
6656 | + * | ||
6657 | + * This program is free software; you can redistribute it and/or modify | ||
6658 | + * it under the terms of the GNU General Public License version 2 as | ||
6659 | + * published by the Free Software Foundation. | ||
6660 | + */ | ||
6661 | + | ||
6662 | +#include "union.h" | ||
6663 | + | ||
6664 | +/* Pass an unionfs dentry and an index. It will try to create a whiteout | ||
6665 | + * for the filename in dentry, and will try in branch 'index'. On error, | ||
6666 | + * it will proceed to a branch to the left. | ||
6667 | + */ | ||
6668 | +int create_whiteout(struct dentry *dentry, int start) | ||
6669 | +{ | ||
6670 | + int bstart, bend, bindex; | ||
6671 | + struct dentry *hidden_dir_dentry; | ||
6672 | + struct dentry *hidden_dentry; | ||
6673 | + struct dentry *hidden_wh_dentry; | ||
6674 | + char *name = NULL; | ||
6675 | + int err = -EINVAL; | ||
6676 | + | ||
6677 | + verify_locked(dentry); | ||
6678 | + | ||
6679 | + bstart = dbstart(dentry); | ||
6680 | + bend = dbend(dentry); | ||
6681 | + | ||
6682 | + /* create dentry's whiteout equivalent */ | ||
6683 | + name = alloc_whname(dentry->d_name.name, dentry->d_name.len); | ||
6684 | + if (IS_ERR(name)) { | ||
6685 | + err = PTR_ERR(name); | ||
6686 | + goto out; | ||
6687 | + } | ||
6688 | + | ||
6689 | + for (bindex = start; bindex >= 0; bindex--) { | ||
6690 | + hidden_dentry = unionfs_lower_dentry_idx(dentry, bindex); | ||
6691 | + | ||
6692 | + if (!hidden_dentry) { | ||
6693 | + /* if hidden dentry is not present, create the entire | ||
6694 | + * hidden dentry directory structure and go ahead. | ||
6695 | + * Since we want to just create whiteout, we only want | ||
6696 | + * the parent dentry, and hence get rid of this dentry. | ||
6697 | + */ | ||
6698 | + hidden_dentry = create_parents(dentry->d_inode, | ||
6699 | + dentry, bindex); | ||
6700 | + if (!hidden_dentry || IS_ERR(hidden_dentry)) { | ||
6701 | + printk(KERN_DEBUG "create_parents failed for " | ||
6702 | + "bindex = %d\n", bindex); | ||
6703 | + continue; | ||
6704 | + } | ||
6705 | + } | ||
6706 | + | ||
6707 | + hidden_wh_dentry = lookup_one_len(name, hidden_dentry->d_parent, | ||
6708 | + dentry->d_name.len + UNIONFS_WHLEN); | ||
6709 | + if (IS_ERR(hidden_wh_dentry)) | ||
6710 | + continue; | ||
6711 | + | ||
6712 | + /* The whiteout already exists. This used to be impossible, but | ||
6713 | + * now is possible because of opaqueness. | ||
6714 | + */ | ||
6715 | + if (hidden_wh_dentry->d_inode) { | ||
6716 | + dput(hidden_wh_dentry); | ||
6717 | + err = 0; | ||
6718 | + goto out; | ||
6719 | + } | ||
6720 | + | ||
6721 | + hidden_dir_dentry = lock_parent(hidden_wh_dentry); | ||
6722 | + if (!(err = is_robranch_super(dentry->d_sb, bindex))) { | ||
6723 | + err = vfs_create(hidden_dir_dentry->d_inode, | ||
6724 | + hidden_wh_dentry, | ||
6725 | + ~current->fs->umask & S_IRWXUGO, NULL); | ||
6726 | + | ||
6727 | + } | ||
6728 | + unlock_dir(hidden_dir_dentry); | ||
6729 | + dput(hidden_wh_dentry); | ||
6730 | + | ||
6731 | + if (!err || !IS_COPYUP_ERR(err)) | ||
6732 | + break; | ||
6733 | + } | ||
6734 | + | ||
6735 | + /* set dbopaque so that lookup will not proceed after this branch */ | ||
6736 | + if (!err) | ||
6737 | + set_dbopaque(dentry, bindex); | ||
6738 | + | ||
6739 | +out: | ||
6740 | + kfree(name); | ||
6741 | + return err; | ||
6742 | +} | ||
6743 | + | ||
6744 | +/* This is a helper function for rename, which ends up with hosed over dentries | ||
6745 | + * when it needs to revert. | ||
6746 | + */ | ||
6747 | +int unionfs_refresh_hidden_dentry(struct dentry *dentry, int bindex) | ||
6748 | +{ | ||
6749 | + struct dentry *hidden_dentry; | ||
6750 | + struct dentry *hidden_parent; | ||
6751 | + int err = 0; | ||
6752 | + | ||
6753 | + verify_locked(dentry); | ||
6754 | + | ||
6755 | + unionfs_lock_dentry(dentry->d_parent); | ||
6756 | + hidden_parent = unionfs_lower_dentry_idx(dentry->d_parent, bindex); | ||
6757 | + unionfs_unlock_dentry(dentry->d_parent); | ||
6758 | + | ||
6759 | + BUG_ON(!S_ISDIR(hidden_parent->d_inode->i_mode)); | ||
6760 | + | ||
6761 | + hidden_dentry = lookup_one_len(dentry->d_name.name, hidden_parent, | ||
6762 | + dentry->d_name.len); | ||
6763 | + if (IS_ERR(hidden_dentry)) { | ||
6764 | + err = PTR_ERR(hidden_dentry); | ||
6765 | + goto out; | ||
6766 | + } | ||
6767 | + | ||
6768 | + dput(unionfs_lower_dentry_idx(dentry, bindex)); | ||
6769 | + iput(unionfs_lower_inode_idx(dentry->d_inode, bindex)); | ||
6770 | + unionfs_set_lower_inode_idx(dentry->d_inode, bindex, NULL); | ||
6771 | + | ||
6772 | + if (!hidden_dentry->d_inode) { | ||
6773 | + dput(hidden_dentry); | ||
6774 | + unionfs_set_lower_dentry_idx(dentry, bindex, NULL); | ||
6775 | + } else { | ||
6776 | + unionfs_set_lower_dentry_idx(dentry, bindex, hidden_dentry); | ||
6777 | + unionfs_set_lower_inode_idx(dentry->d_inode, bindex, | ||
6778 | + igrab(hidden_dentry->d_inode)); | ||
6779 | + } | ||
6780 | + | ||
6781 | +out: | ||
6782 | + return err; | ||
6783 | +} | ||
6784 | + | ||
6785 | +int make_dir_opaque(struct dentry *dentry, int bindex) | ||
6786 | +{ | ||
6787 | + int err = 0; | ||
6788 | + struct dentry *hidden_dentry, *diropq; | ||
6789 | + struct inode *hidden_dir; | ||
6790 | + | ||
6791 | + hidden_dentry = unionfs_lower_dentry_idx(dentry, bindex); | ||
6792 | + hidden_dir = hidden_dentry->d_inode; | ||
6793 | + BUG_ON(!S_ISDIR(dentry->d_inode->i_mode) || | ||
6794 | + !S_ISDIR(hidden_dir->i_mode)); | ||
6795 | + | ||
6796 | + mutex_lock(&hidden_dir->i_mutex); | ||
6797 | + diropq = lookup_one_len(UNIONFS_DIR_OPAQUE, hidden_dentry, | ||
6798 | + sizeof(UNIONFS_DIR_OPAQUE) - 1); | ||
6799 | + if (IS_ERR(diropq)) { | ||
6800 | + err = PTR_ERR(diropq); | ||
6801 | + goto out; | ||
6802 | + } | ||
6803 | + | ||
6804 | + if (!diropq->d_inode) | ||
6805 | + err = vfs_create(hidden_dir, diropq, S_IRUGO, NULL); | ||
6806 | + if (!err) | ||
6807 | + set_dbopaque(dentry, bindex); | ||
6808 | + | ||
6809 | + dput(diropq); | ||
6810 | + | ||
6811 | +out: | ||
6812 | + mutex_unlock(&hidden_dir->i_mutex); | ||
6813 | + return err; | ||
6814 | +} | ||
6815 | + | ||
6816 | +/* returns the sum of the n_link values of all the underlying inodes of the | ||
6817 | + * passed inode | ||
6818 | + */ | ||
6819 | +int unionfs_get_nlinks(struct inode *inode) | ||
6820 | +{ | ||
6821 | + int sum_nlinks = 0; | ||
6822 | + int dirs = 0; | ||
6823 | + int bindex; | ||
6824 | + struct inode *hidden_inode; | ||
6825 | + | ||
6826 | + /* don't bother to do all the work since we're unlinked */ | ||
6827 | + if (inode->i_nlink == 0) | ||
6828 | + return 0; | ||
6829 | + | ||
6830 | + if (!S_ISDIR(inode->i_mode)) | ||
6831 | + return unionfs_lower_inode(inode)->i_nlink; | ||
6832 | + | ||
6833 | + for (bindex = ibstart(inode); bindex <= ibend(inode); bindex++) { | ||
6834 | + hidden_inode = unionfs_lower_inode_idx(inode, bindex); | ||
6835 | + | ||
6836 | + /* ignore files */ | ||
6837 | + if (!hidden_inode || !S_ISDIR(hidden_inode->i_mode)) | ||
6838 | + continue; | ||
6839 | + | ||
6840 | + BUG_ON(hidden_inode->i_nlink < 0); | ||
6841 | + | ||
6842 | + /* A deleted directory. */ | ||
6843 | + if (hidden_inode->i_nlink == 0) | ||
6844 | + continue; | ||
6845 | + dirs++; | ||
6846 | + | ||
6847 | + /* | ||
6848 | + * A broken directory... | ||
6849 | + * | ||
6850 | + * Some filesystems don't properly set the number of links | ||
6851 | + * on empty directories | ||
6852 | + */ | ||
6853 | + if (hidden_inode->i_nlink == 1) | ||
6854 | + sum_nlinks += 2; | ||
6855 | + else | ||
6856 | + sum_nlinks += (hidden_inode->i_nlink - 2); | ||
6857 | + } | ||
6858 | + | ||
6859 | + return (!dirs ? 0 : sum_nlinks + 2); | ||
6860 | +} | ||
6861 | + | ||
6862 | +/* construct whiteout filename */ | ||
6863 | +char *alloc_whname(const char *name, int len) | ||
6864 | +{ | ||
6865 | + char *buf; | ||
6866 | + | ||
6867 | + buf = kmalloc(len + UNIONFS_WHLEN + 1, GFP_KERNEL); | ||
6868 | + if (!buf) | ||
6869 | + return ERR_PTR(-ENOMEM); | ||
6870 | + | ||
6871 | + strcpy(buf, UNIONFS_WHPFX); | ||
6872 | + strlcat(buf, name, len + UNIONFS_WHLEN + 1); | ||
6873 | + | ||
6874 | + return buf; | ||
6875 | +} | ||
6876 | + | ||
6877 | diff --git a/fs/unionfs/super.c b/fs/unionfs/super.c | ||
6878 | new file mode 100644 | ||
6879 | index 0000000..02c0cc8 | ||
6880 | --- /dev/null | ||
6881 | +++ b/fs/unionfs/super.c | ||
6882 | @@ -0,0 +1,965 @@ | ||
6883 | +/* | ||
6884 | + * Copyright (c) 2003-2007 Erez Zadok | ||
6885 | + * Copyright (c) 2003-2006 Charles P. Wright | ||
6886 | + * Copyright (c) 2005-2007 Josef 'Jeff' Sipek | ||
6887 | + * Copyright (c) 2005-2006 Junjiro Okajima | ||
6888 | + * Copyright (c) 2005 Arun M. Krishnakumar | ||
6889 | + * Copyright (c) 2004-2006 David P. Quigley | ||
6890 | + * Copyright (c) 2003-2004 Mohammad Nayyer Zubair | ||
6891 | + * Copyright (c) 2003 Puja Gupta | ||
6892 | + * Copyright (c) 2003 Harikesavan Krishnan | ||
6893 | + * Copyright (c) 2003-2007 Stony Brook University | ||
6894 | + * Copyright (c) 2003-2007 The Research Foundation of State University of New York | ||
6895 | + * | ||
6896 | + * This program is free software; you can redistribute it and/or modify | ||
6897 | + * it under the terms of the GNU General Public License version 2 as | ||
6898 | + * published by the Free Software Foundation. | ||
6899 | + */ | ||
6900 | + | ||
6901 | +#include "union.h" | ||
6902 | + | ||
6903 | +/* The inode cache is used with alloc_inode for both our inode info and the | ||
6904 | + * vfs inode. | ||
6905 | + */ | ||
6906 | +static struct kmem_cache *unionfs_inode_cachep; | ||
6907 | + | ||
6908 | +static void unionfs_read_inode(struct inode *inode) | ||
6909 | +{ | ||
6910 | + static struct address_space_operations unionfs_empty_aops; | ||
6911 | + int size; | ||
6912 | + struct unionfs_inode_info *info = UNIONFS_I(inode); | ||
6913 | + | ||
6914 | + if (!info) { | ||
6915 | + printk(KERN_ERR "No kernel memory when allocating inode " | ||
6916 | + "private data!\n"); | ||
6917 | + BUG(); | ||
6918 | + } | ||
6919 | + | ||
6920 | + memset(info, 0, offsetof(struct unionfs_inode_info, vfs_inode)); | ||
6921 | + info->bstart = -1; | ||
6922 | + info->bend = -1; | ||
6923 | + atomic_set(&info->generation, | ||
6924 | + atomic_read(&UNIONFS_SB(inode->i_sb)->generation)); | ||
6925 | + spin_lock_init(&info->rdlock); | ||
6926 | + info->rdcount = 1; | ||
6927 | + info->hashsize = -1; | ||
6928 | + INIT_LIST_HEAD(&info->readdircache); | ||
6929 | + | ||
6930 | + size = sbmax(inode->i_sb) * sizeof(struct inode *); | ||
6931 | + info->lower_inodes = kzalloc(size, GFP_KERNEL); | ||
6932 | + if (!info->lower_inodes) { | ||
6933 | + printk(KERN_ERR "No kernel memory when allocating lower-" | ||
6934 | + "pointer array!\n"); | ||
6935 | + BUG(); | ||
6936 | + } | ||
6937 | + | ||
6938 | + inode->i_version++; | ||
6939 | + inode->i_op = &unionfs_main_iops; | ||
6940 | + inode->i_fop = &unionfs_main_fops; | ||
6941 | + | ||
6942 | + /* I don't think ->a_ops is ever allowed to be NULL */ | ||
6943 | + inode->i_mapping->a_ops = &unionfs_empty_aops; | ||
6944 | +} | ||
6945 | + | ||
6946 | +static void unionfs_put_inode(struct inode *inode) | ||
6947 | +{ | ||
6948 | + /* | ||
6949 | + * This is really funky stuff: | ||
6950 | + * Basically, if i_count == 1, iput will then decrement it and this | ||
6951 | + * inode will be destroyed. It is currently holding a reference to the | ||
6952 | + * hidden inode. Therefore, it needs to release that reference by | ||
6953 | + * calling iput on the hidden inode. iput() _will_ do it for us (by | ||
6954 | + * calling our clear_inode), but _only_ if i_nlink == 0. The problem | ||
6955 | + * is, NFS keeps i_nlink == 1 for silly_rename'd files. So we must for | ||
6956 | + * our i_nlink to 0 here to trick iput() into calling our clear_inode. | ||
6957 | + */ | ||
6958 | + | ||
6959 | + if (atomic_read(&inode->i_count) == 1) | ||
6960 | + inode->i_nlink = 0; | ||
6961 | +} | ||
6962 | + | ||
6963 | +/* | ||
6964 | + * we now define delete_inode, because there are two VFS paths that may | ||
6965 | + * destroy an inode: one of them calls clear inode before doing everything | ||
6966 | + * else that's needed, and the other is fine. This way we truncate the inode | ||
6967 | + * size (and its pages) and then clear our own inode, which will do an iput | ||
6968 | + * on our and the lower inode. | ||
6969 | + */ | ||
6970 | +static void unionfs_delete_inode(struct inode *inode) | ||
6971 | +{ | ||
6972 | + inode->i_size = 0; /* every f/s seems to do that */ | ||
6973 | + | ||
6974 | + clear_inode(inode); | ||
6975 | +} | ||
6976 | + | ||
6977 | +/* final actions when unmounting a file system */ | ||
6978 | +static void unionfs_put_super(struct super_block *sb) | ||
6979 | +{ | ||
6980 | + int bindex, bstart, bend; | ||
6981 | + struct unionfs_sb_info *spd; | ||
6982 | + int leaks = 0; | ||
6983 | + | ||
6984 | + spd = UNIONFS_SB(sb); | ||
6985 | + if (!spd) | ||
6986 | + return; | ||
6987 | + | ||
6988 | + bstart = sbstart(sb); | ||
6989 | + bend = sbend(sb); | ||
6990 | + | ||
6991 | + /* Make sure we have no leaks of branchget/branchput. */ | ||
6992 | + for (bindex = bstart; bindex <= bend; bindex++) | ||
6993 | + if (branch_count(sb, bindex) != 0) { | ||
6994 | + printk("unionfs: branch %d has %d references left!\n", | ||
6995 | + bindex, branch_count(sb,bindex)); | ||
6996 | + leaks = 1; | ||
6997 | + } | ||
6998 | + BUG_ON(leaks != 0); | ||
6999 | + | ||
7000 | + kfree(spd->data); | ||
7001 | + kfree(spd); | ||
7002 | + sb->s_fs_info = NULL; | ||
7003 | +} | ||
7004 | + | ||
7005 | +/* Since people use this to answer the "How big of a file can I write?" | ||
7006 | + * question, we report the size of the highest priority branch as the size of | ||
7007 | + * the union. | ||
7008 | + */ | ||
7009 | +static int unionfs_statfs(struct dentry *dentry, struct kstatfs *buf) | ||
7010 | +{ | ||
7011 | + int err = 0; | ||
7012 | + struct super_block *sb, *hidden_sb; | ||
7013 | + | ||
7014 | + BUG_ON(!is_valid_dentry(dentry)); | ||
7015 | + | ||
7016 | + sb = dentry->d_sb; | ||
7017 | + | ||
7018 | + unionfs_read_lock(sb); | ||
7019 | + hidden_sb = unionfs_lower_super_idx(sb, sbstart(sb)); | ||
7020 | + unionfs_read_unlock(sb); | ||
7021 | + err = vfs_statfs(hidden_sb->s_root, buf); | ||
7022 | + | ||
7023 | + buf->f_type = UNIONFS_SUPER_MAGIC; | ||
7024 | + buf->f_namelen -= UNIONFS_WHLEN; | ||
7025 | + | ||
7026 | + memset(&buf->f_fsid, 0, sizeof(__kernel_fsid_t)); | ||
7027 | + memset(&buf->f_spare, 0, sizeof(buf->f_spare)); | ||
7028 | + | ||
7029 | + return err; | ||
7030 | +} | ||
7031 | + | ||
7032 | +/* handle mode changing during remount */ | ||
7033 | +static noinline int do_remount_mode_option(char *optarg, int cur_branches, | ||
7034 | + struct unionfs_data *new_data, | ||
7035 | + struct path *new_lower_paths) | ||
7036 | +{ | ||
7037 | + int err = -EINVAL; | ||
7038 | + int perms, idx; | ||
7039 | + char *modename = strchr(optarg, '='); | ||
7040 | + struct nameidata nd; | ||
7041 | + | ||
7042 | + /* by now, optarg contains the branch name */ | ||
7043 | + if (!*optarg) { | ||
7044 | + printk("unionfs: no branch specified for mode change.\n"); | ||
7045 | + goto out; | ||
7046 | + } | ||
7047 | + if (!modename) { | ||
7048 | + printk("unionfs: branch \"%s\" requires a mode.\n", optarg); | ||
7049 | + goto out; | ||
7050 | + } | ||
7051 | + *modename++ = '\0'; | ||
7052 | + perms = __parse_branch_mode(modename); | ||
7053 | + if (perms == 0) { | ||
7054 | + printk("unionfs: invalid mode \"%s\" for \"%s\".\n", | ||
7055 | + modename, optarg); | ||
7056 | + goto out; | ||
7057 | + } | ||
7058 | + | ||
7059 | + /* | ||
7060 | + * Find matching branch index. For now, this assumes that nothing | ||
7061 | + * has been mounted on top of this Unionfs stack. Once we have /odf | ||
7062 | + * and cache-coherency resolved, we'll address the branch-path | ||
7063 | + * uniqueness. | ||
7064 | + */ | ||
7065 | + err = path_lookup(optarg, LOOKUP_FOLLOW, &nd); | ||
7066 | + if (err) { | ||
7067 | + printk(KERN_WARNING "unionfs: error accessing " | ||
7068 | + "hidden directory \"%s\" (error %d)\n", | ||
7069 | + optarg, err); | ||
7070 | + goto out; | ||
7071 | + } | ||
7072 | + for (idx=0; idx<cur_branches; idx++) | ||
7073 | + if (nd.mnt == new_lower_paths[idx].mnt && | ||
7074 | + nd.dentry == new_lower_paths[idx].dentry) | ||
7075 | + break; | ||
7076 | + path_release(&nd); /* no longer needed */ | ||
7077 | + if (idx == cur_branches) { | ||
7078 | + err = -ENOENT; /* err may have been reset above */ | ||
7079 | + printk(KERN_WARNING "unionfs: branch \"%s\" " | ||
7080 | + "not found\n", optarg); | ||
7081 | + goto out; | ||
7082 | + } | ||
7083 | + /* check/change mode for existing branch */ | ||
7084 | + /* we don't warn if perms==branchperms */ | ||
7085 | + new_data[idx].branchperms = perms; | ||
7086 | + err = 0; | ||
7087 | +out: | ||
7088 | + return err; | ||
7089 | +} | ||
7090 | + | ||
7091 | +/* handle branch deletion during remount */ | ||
7092 | +static noinline int do_remount_del_option(char *optarg, int cur_branches, | ||
7093 | + struct unionfs_data *new_data, | ||
7094 | + struct path *new_lower_paths) | ||
7095 | +{ | ||
7096 | + int err = -EINVAL; | ||
7097 | + int idx; | ||
7098 | + struct nameidata nd; | ||
7099 | + /* optarg contains the branch name to delete */ | ||
7100 | + | ||
7101 | + /* | ||
7102 | + * Find matching branch index. For now, this assumes that nothing | ||
7103 | + * has been mounted on top of this Unionfs stack. Once we have /odf | ||
7104 | + * and cache-coherency resolved, we'll address the branch-path | ||
7105 | + * uniqueness. | ||
7106 | + */ | ||
7107 | + err = path_lookup(optarg, LOOKUP_FOLLOW, &nd); | ||
7108 | + if (err) { | ||
7109 | + printk(KERN_WARNING "unionfs: error accessing " | ||
7110 | + "hidden directory \"%s\" (error %d)\n", | ||
7111 | + optarg, err); | ||
7112 | + goto out; | ||
7113 | + } | ||
7114 | + for (idx=0; idx < cur_branches; idx++) | ||
7115 | + if (nd.mnt == new_lower_paths[idx].mnt && | ||
7116 | + nd.dentry == new_lower_paths[idx].dentry) | ||
7117 | + break; | ||
7118 | + path_release(&nd); /* no longer needed */ | ||
7119 | + if (idx == cur_branches) { | ||
7120 | + printk(KERN_WARNING "unionfs: branch \"%s\" " | ||
7121 | + "not found\n", optarg); | ||
7122 | + err = -ENOENT; | ||
7123 | + goto out; | ||
7124 | + } | ||
7125 | + /* check if there are any open files on the branch to be deleted */ | ||
7126 | + if (atomic_read(&new_data[idx].open_files) > 0) { | ||
7127 | + err = -EBUSY; | ||
7128 | + goto out; | ||
7129 | + } | ||
7130 | + | ||
7131 | + /* | ||
7132 | + * Now we have to delete the branch. First, release any handles it | ||
7133 | + * has. Then, move the remaining array indexes past "idx" in | ||
7134 | + * new_data and new_lower_paths one to the left. Finally, adjust | ||
7135 | + * cur_branches. | ||
7136 | + */ | ||
7137 | + pathput(&new_lower_paths[idx]); | ||
7138 | + | ||
7139 | + if (idx < cur_branches - 1) { | ||
7140 | + /* if idx==cur_branches-1, we delete last branch: easy */ | ||
7141 | + memmove(&new_data[idx], &new_data[idx+1], | ||
7142 | + (cur_branches - 1 - idx) * sizeof(struct unionfs_data)); | ||
7143 | + memmove(&new_lower_paths[idx], &new_lower_paths[idx+1], | ||
7144 | + (cur_branches - 1 - idx) * sizeof(struct path)); | ||
7145 | + } | ||
7146 | + | ||
7147 | + err = 0; | ||
7148 | +out: | ||
7149 | + return err; | ||
7150 | +} | ||
7151 | + | ||
7152 | +/* handle branch insertion during remount */ | ||
7153 | +static noinline int do_remount_add_option(char *optarg, int cur_branches, | ||
7154 | + struct unionfs_data *new_data, | ||
7155 | + struct path *new_lower_paths, | ||
7156 | + int *high_branch_id) | ||
7157 | +{ | ||
7158 | + int err = -EINVAL; | ||
7159 | + int perms; | ||
7160 | + int idx = 0; /* default: insert at beginning */ | ||
7161 | + char *new_branch , *modename = NULL; | ||
7162 | + struct nameidata nd; | ||
7163 | + | ||
7164 | + /* | ||
7165 | + * optarg can be of several forms: | ||
7166 | + * | ||
7167 | + * /bar:/foo insert /foo before /bar | ||
7168 | + * /bar:/foo=ro insert /foo in ro mode before /bar | ||
7169 | + * /foo insert /foo in the beginning (prepend) | ||
7170 | + * :/foo insert /foo at the end (append) | ||
7171 | + */ | ||
7172 | + if (*optarg == ':') { /* append? */ | ||
7173 | + new_branch = optarg + 1; /* skip ':' */ | ||
7174 | + idx = cur_branches; | ||
7175 | + goto found_insertion_point; | ||
7176 | + } | ||
7177 | + new_branch = strchr(optarg, ':'); | ||
7178 | + if (!new_branch) { /* prepend? */ | ||
7179 | + new_branch = optarg; | ||
7180 | + goto found_insertion_point; | ||
7181 | + } | ||
7182 | + *new_branch++ = '\0'; /* holds path+mode of new branch */ | ||
7183 | + | ||
7184 | + /* | ||
7185 | + * Find matching branch index. For now, this assumes that nothing | ||
7186 | + * has been mounted on top of this Unionfs stack. Once we have /odf | ||
7187 | + * and cache-coherency resolved, we'll address the branch-path | ||
7188 | + * uniqueness. | ||
7189 | + */ | ||
7190 | + err = path_lookup(optarg, LOOKUP_FOLLOW, &nd); | ||
7191 | + if (err) { | ||
7192 | + printk(KERN_WARNING "unionfs: error accessing " | ||
7193 | + "hidden directory \"%s\" (error %d)\n", | ||
7194 | + optarg, err); | ||
7195 | + goto out; | ||
7196 | + } | ||
7197 | + for (idx=0; idx < cur_branches; idx++) | ||
7198 | + if (nd.mnt == new_lower_paths[idx].mnt && | ||
7199 | + nd.dentry == new_lower_paths[idx].dentry) | ||
7200 | + break; | ||
7201 | + path_release(&nd); /* no longer needed */ | ||
7202 | + if (idx == cur_branches) { | ||
7203 | + printk(KERN_WARNING "unionfs: branch \"%s\" " | ||
7204 | + "not found\n", optarg); | ||
7205 | + err = -ENOENT; | ||
7206 | + goto out; | ||
7207 | + } | ||
7208 | + | ||
7209 | + /* | ||
7210 | + * At this point idx will hold the index where the new branch should | ||
7211 | + * be inserted before. | ||
7212 | + */ | ||
7213 | +found_insertion_point: | ||
7214 | + /* find the mode for the new branch */ | ||
7215 | + if (new_branch) | ||
7216 | + modename = strchr(new_branch, '='); | ||
7217 | + if (modename) | ||
7218 | + *modename++ = '\0'; | ||
7219 | + perms = parse_branch_mode(modename); | ||
7220 | + | ||
7221 | + if (!new_branch || !*new_branch) { | ||
7222 | + printk(KERN_WARNING "unionfs: null new branch\n"); | ||
7223 | + err = -EINVAL; | ||
7224 | + goto out; | ||
7225 | + } | ||
7226 | + err = path_lookup(new_branch, LOOKUP_FOLLOW, &nd); | ||
7227 | + if (err) { | ||
7228 | + printk(KERN_WARNING "unionfs: error accessing " | ||
7229 | + "hidden directory \"%s\" (error %d)\n", | ||
7230 | + new_branch, err); | ||
7231 | + goto out; | ||
7232 | + } | ||
7233 | + /* it's probably safe to check_mode the new branch to insert */ | ||
7234 | + if ((err = check_branch(&nd))) { | ||
7235 | + printk(KERN_WARNING "unionfs: hidden directory " | ||
7236 | + "\"%s\" is not a valid branch\n", optarg); | ||
7237 | + path_release(&nd); | ||
7238 | + goto out; | ||
7239 | + } | ||
7240 | + | ||
7241 | + /* | ||
7242 | + * Now we have to insert the new branch. But first, move the bits | ||
7243 | + * to make space for the new branch, if needed. Finally, adjust | ||
7244 | + * cur_branches. | ||
7245 | + * We don't release nd here; it's kept until umount/remount. | ||
7246 | + */ | ||
7247 | + if (idx < cur_branches) { | ||
7248 | + /* if idx==cur_branches, we append: easy */ | ||
7249 | + memmove(&new_data[idx+1], &new_data[idx], | ||
7250 | + (cur_branches - idx) * sizeof(struct unionfs_data)); | ||
7251 | + memmove(&new_lower_paths[idx+1], &new_lower_paths[idx], | ||
7252 | + (cur_branches - idx) * sizeof(struct path)); | ||
7253 | + } | ||
7254 | + new_lower_paths[idx].dentry = nd.dentry; | ||
7255 | + new_lower_paths[idx].mnt = nd.mnt; | ||
7256 | + | ||
7257 | + new_data[idx].sb = nd.dentry->d_sb; | ||
7258 | + atomic_set(&new_data[idx].open_files, 0); | ||
7259 | + new_data[idx].branchperms = perms; | ||
7260 | + new_data[idx].branch_id = ++*high_branch_id; /* assign new branch ID */ | ||
7261 | + | ||
7262 | + err = 0; | ||
7263 | +out: | ||
7264 | + return err; | ||
7265 | +} | ||
7266 | + | ||
7267 | + | ||
7268 | +/* | ||
7269 | + * Support branch management options on remount. | ||
7270 | + * | ||
7271 | + * See Documentation/filesystems/unionfs/ for details. | ||
7272 | + * | ||
7273 | + * @flags: numeric mount options | ||
7274 | + * @options: mount options string | ||
7275 | + * | ||
7276 | + * This function can rearrange a mounted union dynamically, adding and | ||
7277 | + * removing branches, including changing branch modes. Clearly this has to | ||
7278 | + * be done safely and atomically. Luckily, the VFS already calls this | ||
7279 | + * function with lock_super(sb) and lock_kernel() held, preventing | ||
7280 | + * concurrent mixing of new mounts, remounts, and unmounts. Moreover, | ||
7281 | + * do_remount_sb(), our caller function, already called shrink_dcache_sb(sb) | ||
7282 | + * to purge dentries/inodes from our superblock, and also called | ||
7283 | + * fsync_super(sb) to purge any dirty pages. So we're good. | ||
7284 | + * | ||
7285 | + * XXX: however, our remount code may also need to invalidate mapped pages | ||
7286 | + * so as to force them to be re-gotten from the (newly reconfigured) lower | ||
7287 | + * branches. This has to wait for proper mmap and cache coherency support | ||
7288 | + * in the VFS. | ||
7289 | + * | ||
7290 | + */ | ||
7291 | +static int unionfs_remount_fs(struct super_block *sb, int *flags, | ||
7292 | + char *options) | ||
7293 | +{ | ||
7294 | + int err = 0; | ||
7295 | + int i; | ||
7296 | + char *optionstmp, *tmp_to_free; /* kstrdup'ed of "options" */ | ||
7297 | + char *optname; | ||
7298 | + int cur_branches; /* no. of current branches */ | ||
7299 | + int new_branches; /* no. of branches actually left in the end */ | ||
7300 | + int add_branches; /* est. no. of branches to add */ | ||
7301 | + int del_branches; /* est. no. of branches to del */ | ||
7302 | + int max_branches; /* max possible no. of branches */ | ||
7303 | + struct unionfs_data *new_data = NULL, *tmp_data = NULL; | ||
7304 | + struct path *new_lower_paths = NULL, *tmp_lower_paths = NULL; | ||
7305 | + int new_high_branch_id; /* new high branch ID */ | ||
7306 | + | ||
7307 | + unionfs_write_lock(sb); | ||
7308 | + | ||
7309 | + /* | ||
7310 | + * The VFS will take care of "ro" and "rw" flags, and we can safely | ||
7311 | + * ignore MS_SILENT, but anything else left over is an error. So we | ||
7312 | + * need to check if any other flags may have been passed (none are | ||
7313 | + * allowed/supported as of now). | ||
7314 | + */ | ||
7315 | + if ((*flags & ~(MS_RDONLY | MS_SILENT)) != 0) { | ||
7316 | + printk(KERN_WARNING | ||
7317 | + "unionfs: remount flags 0x%x unsupported\n", *flags); | ||
7318 | + err = -EINVAL; | ||
7319 | + goto out_error; | ||
7320 | + } | ||
7321 | + | ||
7322 | + /* | ||
7323 | + * If 'options' is NULL, it's probably because the user just changed | ||
7324 | + * the union to a "ro" or "rw" and the VFS took care of it. So | ||
7325 | + * nothing to do and we're done. | ||
7326 | + */ | ||
7327 | + if (!options || options[0] == '\0') | ||
7328 | + goto out_error; | ||
7329 | + | ||
7330 | + /* | ||
7331 | + * Find out how many branches we will have in the end, counting | ||
7332 | + * "add" and "del" commands. Copy the "options" string because | ||
7333 | + * strsep modifies the string and we need it later. | ||
7334 | + */ | ||
7335 | + optionstmp = tmp_to_free = kstrdup(options, GFP_KERNEL); | ||
7336 | + if (!optionstmp) { | ||
7337 | + err = -ENOMEM; | ||
7338 | + goto out_free; | ||
7339 | + } | ||
7340 | + new_branches = cur_branches = sbmax(sb); /* current no. branches */ | ||
7341 | + add_branches = del_branches = 0; | ||
7342 | + new_high_branch_id = sbhbid(sb); /* save current high_branch_id */ | ||
7343 | + while ((optname = strsep(&optionstmp, ",")) != NULL) { | ||
7344 | + char *optarg; | ||
7345 | + | ||
7346 | + if (!optname || !*optname) | ||
7347 | + continue; | ||
7348 | + | ||
7349 | + optarg = strchr(optname, '='); | ||
7350 | + if (optarg) | ||
7351 | + *optarg++ = '\0'; | ||
7352 | + | ||
7353 | + if (!strcmp("add", optname)) | ||
7354 | + add_branches++; | ||
7355 | + else if (!strcmp("del", optname)) | ||
7356 | + del_branches++; | ||
7357 | + } | ||
7358 | + kfree(tmp_to_free); | ||
7359 | + /* after all changes, will we have at least one branch left? */ | ||
7360 | + if ((new_branches + add_branches - del_branches) < 1) { | ||
7361 | + printk(KERN_WARNING | ||
7362 | + "unionfs: no branches left after remount\n"); | ||
7363 | + err = -EINVAL; | ||
7364 | + goto out_free; | ||
7365 | + } | ||
7366 | + | ||
7367 | + /* | ||
7368 | + * Since we haven't actually parsed all the add/del options, nor | ||
7369 | + * have we checked them for errors, we don't know for sure how many | ||
7370 | + * branches we will have after all changes have taken place. In | ||
7371 | + * fact, the total number of branches left could be less than what | ||
7372 | + * we have now. So we need to allocate space for a temporary | ||
7373 | + * placeholder that is at least as large as the maximum number of | ||
7374 | + * branches we *could* have, which is the current number plus all | ||
7375 | + * the additions. Once we're done with these temp placeholders, we | ||
7376 | + * may have to re-allocate the final size, copy over from the temp, | ||
7377 | + * and then free the temps (done near the end of this function). | ||
7378 | + */ | ||
7379 | + max_branches = cur_branches + add_branches; | ||
7380 | + /* allocate space for new pointers to hidden dentry */ | ||
7381 | + tmp_data = kcalloc(max_branches, | ||
7382 | + sizeof(struct unionfs_data), GFP_KERNEL); | ||
7383 | + if (!tmp_data) { | ||
7384 | + err = -ENOMEM; | ||
7385 | + goto out_free; | ||
7386 | + } | ||
7387 | + /* allocate space for new pointers to lower paths */ | ||
7388 | + tmp_lower_paths = kcalloc(max_branches, | ||
7389 | + sizeof(struct path), GFP_KERNEL); | ||
7390 | + if (!tmp_lower_paths) { | ||
7391 | + err = -ENOMEM; | ||
7392 | + goto out_free; | ||
7393 | + } | ||
7394 | + /* copy current info into new placeholders, incrementing refcnts */ | ||
7395 | + memcpy(tmp_data, UNIONFS_SB(sb)->data, | ||
7396 | + cur_branches * sizeof(struct unionfs_data)); | ||
7397 | + memcpy(tmp_lower_paths, UNIONFS_D(sb->s_root)->lower_paths, | ||
7398 | + cur_branches * sizeof(struct path)); | ||
7399 | + for (i=0; i<cur_branches; i++) | ||
7400 | + pathget(&tmp_lower_paths[i]); /* drop refs at end of fxn */ | ||
7401 | + | ||
7402 | + /******************************************************************* | ||
7403 | + * For each branch command, do path_lookup on the requested branch, | ||
7404 | + * and apply the change to a temp branch list. To handle errors, we | ||
7405 | + * already dup'ed the old arrays (above), and increased the refcnts | ||
7406 | + * on various f/s objects. So now we can do all the path_lookups | ||
7407 | + * and branch-management commands on the new arrays. If it fail mid | ||
7408 | + * way, we free the tmp arrays and *put all objects. If we succeed, | ||
7409 | + * then we free old arrays and *put its objects, and then replace | ||
7410 | + * the arrays with the new tmp list (we may have to re-allocate the | ||
7411 | + * memory because the temp lists could have been larger than what we | ||
7412 | + * actually needed). | ||
7413 | + *******************************************************************/ | ||
7414 | + | ||
7415 | + while ((optname = strsep(&options, ",")) != NULL) { | ||
7416 | + char *optarg; | ||
7417 | + | ||
7418 | + if (!optname || !*optname) | ||
7419 | + continue; | ||
7420 | + /* | ||
7421 | + * At this stage optname holds a comma-delimited option, but | ||
7422 | + * without the commas. Next, we need to break the string on | ||
7423 | + * the '=' symbol to separate CMD=ARG, where ARG itself can | ||
7424 | + * be KEY=VAL. For example, in mode=/foo=rw, CMD is "mode", | ||
7425 | + * KEY is "/foo", and VAL is "rw". | ||
7426 | + */ | ||
7427 | + optarg = strchr(optname, '='); | ||
7428 | + if (optarg) | ||
7429 | + *optarg++ = '\0'; | ||
7430 | + /* incgen remount option (instead of old ioctl) */ | ||
7431 | + if (!strcmp("incgen", optname)) { | ||
7432 | + err = 0; | ||
7433 | + goto out_no_change; | ||
7434 | + } | ||
7435 | + | ||
7436 | + /* | ||
7437 | + * All of our options take an argument now. (Insert ones | ||
7438 | + * that don't above this check.) So at this stage optname | ||
7439 | + * contains the CMD part and optarg contains the ARG part. | ||
7440 | + */ | ||
7441 | + if (!optarg || !*optarg) { | ||
7442 | + printk("unionfs: all remount options require " | ||
7443 | + "an argument (%s).\n", optname); | ||
7444 | + err = -EINVAL; | ||
7445 | + goto out_release; | ||
7446 | + } | ||
7447 | + | ||
7448 | + if (!strcmp("add", optname)) { | ||
7449 | + err = do_remount_add_option(optarg, new_branches, | ||
7450 | + tmp_data, | ||
7451 | + tmp_lower_paths, | ||
7452 | + &new_high_branch_id); | ||
7453 | + if (err) | ||
7454 | + goto out_release; | ||
7455 | + new_branches++; | ||
7456 | + if (new_branches > UNIONFS_MAX_BRANCHES) { | ||
7457 | + printk("unionfs: command exceeds %d branches\n", | ||
7458 | + UNIONFS_MAX_BRANCHES); | ||
7459 | + err = -E2BIG; | ||
7460 | + goto out_release; | ||
7461 | + } | ||
7462 | + continue; | ||
7463 | + } | ||
7464 | + if (!strcmp("del", optname)) { | ||
7465 | + err = do_remount_del_option(optarg, new_branches, | ||
7466 | + tmp_data, | ||
7467 | + tmp_lower_paths); | ||
7468 | + if (err) | ||
7469 | + goto out_release; | ||
7470 | + new_branches--; | ||
7471 | + continue; | ||
7472 | + } | ||
7473 | + if (!strcmp("mode", optname)) { | ||
7474 | + err = do_remount_mode_option(optarg, new_branches, | ||
7475 | + tmp_data, | ||
7476 | + tmp_lower_paths); | ||
7477 | + if (err) | ||
7478 | + goto out_release; | ||
7479 | + continue; | ||
7480 | + } | ||
7481 | + | ||
7482 | + /* | ||
7483 | + * When you use "mount -o remount,ro", mount(8) will | ||
7484 | + * reportedly pass the original dirs= string from | ||
7485 | + * /proc/mounts. So for now, we have to ignore dirs= and | ||
7486 | + * not consider it an error, unless we want to allow users | ||
7487 | + * to pass dirs= in remount. Note that to allow the VFS to | ||
7488 | + * actually process the ro/rw remount options, we have to | ||
7489 | + * return 0 from this function. | ||
7490 | + */ | ||
7491 | + if (!strcmp("dirs", optname)) { | ||
7492 | + printk(KERN_WARNING | ||
7493 | + "unionfs: remount ignoring option \"%s\".\n", | ||
7494 | + optname); | ||
7495 | + continue; | ||
7496 | + } | ||
7497 | + | ||
7498 | + err = -EINVAL; | ||
7499 | + printk(KERN_WARNING | ||
7500 | + "unionfs: unrecognized option \"%s\"\n", optname); | ||
7501 | + goto out_release; | ||
7502 | + } | ||
7503 | + | ||
7504 | +out_no_change: | ||
7505 | + | ||
7506 | + /****************************************************************** | ||
7507 | + * WE'RE ALMOST DONE: see if we need to allocate a small-sized new | ||
7508 | + * vector, copy the vectors to their correct place, release the | ||
7509 | + * refcnt of the older ones, and return. | ||
7510 | + * Also handle invalidating any pgaes that will have to be re-read. | ||
7511 | + *******************************************************************/ | ||
7512 | + | ||
7513 | + /* | ||
7514 | + * Allocate space for actual pointers, if needed. By the time we | ||
7515 | + * finish this block of code, new_branches and new_lower_paths will | ||
7516 | + * have the correct size. None of this code below would be needed | ||
7517 | + * if the kernel had a realloc() function, at least one capable of | ||
7518 | + * shrinking/truncating an allocation's size (hint, hint). | ||
7519 | + */ | ||
7520 | + if (new_branches < max_branches) { | ||
7521 | + | ||
7522 | + /* allocate space for new pointers to hidden dentry */ | ||
7523 | + new_data = kcalloc(new_branches, | ||
7524 | + sizeof(struct unionfs_data), GFP_KERNEL); | ||
7525 | + if (!new_data) { | ||
7526 | + err = -ENOMEM; | ||
7527 | + goto out_release; | ||
7528 | + } | ||
7529 | + /* allocate space for new pointers to lower paths */ | ||
7530 | + new_lower_paths = kcalloc(new_branches, | ||
7531 | + sizeof(struct path), GFP_KERNEL); | ||
7532 | + if (!new_lower_paths) { | ||
7533 | + err = -ENOMEM; | ||
7534 | + goto out_release; | ||
7535 | + } | ||
7536 | + /* | ||
7537 | + * copy current info into new placeholders, incrementing | ||
7538 | + * refcounts. | ||
7539 | + */ | ||
7540 | + memcpy(new_data, tmp_data, | ||
7541 | + new_branches * sizeof(struct unionfs_data)); | ||
7542 | + memcpy(new_lower_paths, tmp_lower_paths, | ||
7543 | + new_branches * sizeof(struct path)); | ||
7544 | + /* | ||
7545 | + * Since we already hold various refcnts on the objects, we | ||
7546 | + * don't need to redo it here. Just free the older memory | ||
7547 | + * and re-point the pointers. | ||
7548 | + */ | ||
7549 | + kfree(tmp_data); | ||
7550 | + kfree(tmp_lower_paths); | ||
7551 | + /* no need to nullify pointers here */ | ||
7552 | + } else { | ||
7553 | + /* number of branches didn't change, no need to re-alloc */ | ||
7554 | + new_data = tmp_data; | ||
7555 | + new_lower_paths = tmp_lower_paths; | ||
7556 | + } | ||
7557 | + | ||
7558 | + /* | ||
7559 | + * OK, just before we actually put the new set of branches in place, | ||
7560 | + * we need to ensure that our own f/s has no dirty objects left. | ||
7561 | + * Luckily, do_remount_sb() already calls shrink_dcache_sb(sb) and | ||
7562 | + * fsync_super(sb), taking care of dentries, inodes, and dirty | ||
7563 | + * pages. So all that's left is for us to invalidate any leftover | ||
7564 | + * (non-dirty) pages to ensure that they will be re-read from the | ||
7565 | + * new lower branches (and to support mmap). | ||
7566 | + */ | ||
7567 | + | ||
7568 | + /* | ||
7569 | + * No we call drop_pagecache_sb() to invalidate all pages in this | ||
7570 | + * super. This function calls invalidate_inode_pages(mapping), | ||
7571 | + * which calls invalidate_mapping_pages(): the latter, however, will | ||
7572 | + * not invalidate pages which are dirty, locked, under writeback, or | ||
7573 | + * mapped into pagetables. We shouldn't have to worry about dirty | ||
7574 | + * or under-writeback pages, because do_remount_sb() called | ||
7575 | + * fsync_super() which would not have returned until all dirty pages | ||
7576 | + * were flushed. | ||
7577 | + * | ||
7578 | + * But do w have to worry about locked pages? Is there any chance | ||
7579 | + * that in here we'll get locked pages? | ||
7580 | + * | ||
7581 | + * XXX: what about pages mapped into pagetables? Are these pages | ||
7582 | + * which user processes may have mmap(2)'ed? If so, then we need to | ||
7583 | + * invalidate those too, no? Maybe we'll have to write our own | ||
7584 | + * version of invalidate_mapping_pages() which also handled mapped | ||
7585 | + * pages. | ||
7586 | + * | ||
7587 | + * XXX: Alternatively, maybe we should call truncate_inode_pages(), | ||
7588 | + * which use two passes over the pages list, and will truncate all | ||
7589 | + * pages. | ||
7590 | + */ | ||
7591 | + drop_pagecache_sb(sb); | ||
7592 | + | ||
7593 | + /* copy new vectors into their correct place */ | ||
7594 | + tmp_data = UNIONFS_SB(sb)->data; | ||
7595 | + UNIONFS_SB(sb)->data = new_data; | ||
7596 | + new_data = NULL; /* so don't free good pointers below */ | ||
7597 | + tmp_lower_paths = UNIONFS_D(sb->s_root)->lower_paths; | ||
7598 | + UNIONFS_D(sb->s_root)->lower_paths = new_lower_paths; | ||
7599 | + new_lower_paths = NULL; /* so don't free good pointers below */ | ||
7600 | + | ||
7601 | + /* update our unionfs_sb_info and root dentry index of last branch */ | ||
7602 | + i = sbmax(sb); /* save no. of branches to release at end */ | ||
7603 | + sbend(sb) = new_branches - 1; | ||
7604 | + set_dbend(sb->s_root, new_branches - 1); | ||
7605 | + UNIONFS_D(sb->s_root)->bcount = new_branches; | ||
7606 | + new_branches = i; /* no. of branches to release below */ | ||
7607 | + | ||
7608 | + /* maxbytes may have changed */ | ||
7609 | + sb->s_maxbytes = unionfs_lower_super_idx(sb, 0)->s_maxbytes; | ||
7610 | + /* update high branch ID */ | ||
7611 | + sbhbid(sb) = new_high_branch_id; | ||
7612 | + | ||
7613 | + /* update our sb->generation for revalidating objects */ | ||
7614 | + i = atomic_inc_return(&UNIONFS_SB(sb)->generation); | ||
7615 | + atomic_set(&UNIONFS_D(sb->s_root)->generation, i); | ||
7616 | + atomic_set(&UNIONFS_I(sb->s_root->d_inode)->generation, i); | ||
7617 | + if (!(*flags & MS_SILENT)) | ||
7618 | + printk("unionfs: new generation number %d\n", i); | ||
7619 | + err = 0; /* reset to success */ | ||
7620 | + | ||
7621 | + /* | ||
7622 | + * The code above falls through to the next label, and releases the | ||
7623 | + * refcnts of the older ones (stored in tmp_*): if we fell through | ||
7624 | + * here, it means success. However, if we jump directly to this | ||
7625 | + * label from any error above, then an error occurred after we | ||
7626 | + * grabbed various refcnts, and so we have to release the | ||
7627 | + * temporarily constructed structures. | ||
7628 | + */ | ||
7629 | +out_release: | ||
7630 | + /* no need to cleanup/release anything in tmp_data */ | ||
7631 | + if (tmp_lower_paths) | ||
7632 | + for (i=0; i<new_branches; i++) | ||
7633 | + pathput(&tmp_lower_paths[i]); | ||
7634 | +out_free: | ||
7635 | + kfree(tmp_lower_paths); | ||
7636 | + kfree(tmp_data); | ||
7637 | + kfree(new_lower_paths); | ||
7638 | + kfree(new_data); | ||
7639 | +out_error: | ||
7640 | + unionfs_write_unlock(sb); | ||
7641 | + return err; | ||
7642 | +} | ||
7643 | + | ||
7644 | +/* | ||
7645 | + * Called by iput() when the inode reference count reached zero | ||
7646 | + * and the inode is not hashed anywhere. Used to clear anything | ||
7647 | + * that needs to be, before the inode is completely destroyed and put | ||
7648 | + * on the inode free list. | ||
7649 | + */ | ||
7650 | +static void unionfs_clear_inode(struct inode *inode) | ||
7651 | +{ | ||
7652 | + int bindex, bstart, bend; | ||
7653 | + struct inode *hidden_inode; | ||
7654 | + struct list_head *pos, *n; | ||
7655 | + struct unionfs_dir_state *rdstate; | ||
7656 | + | ||
7657 | + list_for_each_safe(pos, n, &UNIONFS_I(inode)->readdircache) { | ||
7658 | + rdstate = list_entry(pos, struct unionfs_dir_state, cache); | ||
7659 | + list_del(&rdstate->cache); | ||
7660 | + free_rdstate(rdstate); | ||
7661 | + } | ||
7662 | + | ||
7663 | + /* Decrement a reference to a hidden_inode, which was incremented | ||
7664 | + * by our read_inode when it was created initially. | ||
7665 | + */ | ||
7666 | + bstart = ibstart(inode); | ||
7667 | + bend = ibend(inode); | ||
7668 | + if (bstart >= 0) { | ||
7669 | + for (bindex = bstart; bindex <= bend; bindex++) { | ||
7670 | + hidden_inode = unionfs_lower_inode_idx(inode, bindex); | ||
7671 | + if (!hidden_inode) | ||
7672 | + continue; | ||
7673 | + iput(hidden_inode); | ||
7674 | + } | ||
7675 | + } | ||
7676 | + | ||
7677 | + kfree(UNIONFS_I(inode)->lower_inodes); | ||
7678 | + UNIONFS_I(inode)->lower_inodes = NULL; | ||
7679 | +} | ||
7680 | + | ||
7681 | +static struct inode *unionfs_alloc_inode(struct super_block *sb) | ||
7682 | +{ | ||
7683 | + struct unionfs_inode_info *i; | ||
7684 | + | ||
7685 | + i = kmem_cache_alloc(unionfs_inode_cachep, GFP_KERNEL); | ||
7686 | + if (!i) | ||
7687 | + return NULL; | ||
7688 | + | ||
7689 | + /* memset everything up to the inode to 0 */ | ||
7690 | + memset(i, 0, offsetof(struct unionfs_inode_info, vfs_inode)); | ||
7691 | + | ||
7692 | + i->vfs_inode.i_version = 1; | ||
7693 | + return &i->vfs_inode; | ||
7694 | +} | ||
7695 | + | ||
7696 | +static void unionfs_destroy_inode(struct inode *inode) | ||
7697 | +{ | ||
7698 | + kmem_cache_free(unionfs_inode_cachep, UNIONFS_I(inode)); | ||
7699 | +} | ||
7700 | + | ||
7701 | +/* unionfs inode cache constructor */ | ||
7702 | +static void init_once(void *v, struct kmem_cache * cachep, unsigned long flags) | ||
7703 | +{ | ||
7704 | + struct unionfs_inode_info *i = v; | ||
7705 | + | ||
7706 | + if ((flags & (SLAB_CTOR_VERIFY | SLAB_CTOR_CONSTRUCTOR)) == | ||
7707 | + SLAB_CTOR_CONSTRUCTOR) | ||
7708 | + inode_init_once(&i->vfs_inode); | ||
7709 | +} | ||
7710 | + | ||
7711 | +int unionfs_init_inode_cache(void) | ||
7712 | +{ | ||
7713 | + int err = 0; | ||
7714 | + | ||
7715 | + unionfs_inode_cachep = | ||
7716 | + kmem_cache_create("unionfs_inode_cache", | ||
7717 | + sizeof(struct unionfs_inode_info), 0, | ||
7718 | + SLAB_RECLAIM_ACCOUNT, init_once, NULL); | ||
7719 | + if (!unionfs_inode_cachep) | ||
7720 | + err = -ENOMEM; | ||
7721 | + return err; | ||
7722 | +} | ||
7723 | + | ||
7724 | +void unionfs_destroy_inode_cache(void) | ||
7725 | +{ | ||
7726 | + if (unionfs_inode_cachep) | ||
7727 | + kmem_cache_destroy(unionfs_inode_cachep); | ||
7728 | +} | ||
7729 | + | ||
7730 | +/* Called when we have a dirty inode, right here we only throw out | ||
7731 | + * parts of our readdir list that are too old. | ||
7732 | + */ | ||
7733 | +static int unionfs_write_inode(struct inode *inode, int sync) | ||
7734 | +{ | ||
7735 | + struct list_head *pos, *n; | ||
7736 | + struct unionfs_dir_state *rdstate; | ||
7737 | + | ||
7738 | + spin_lock(&UNIONFS_I(inode)->rdlock); | ||
7739 | + list_for_each_safe(pos, n, &UNIONFS_I(inode)->readdircache) { | ||
7740 | + rdstate = list_entry(pos, struct unionfs_dir_state, cache); | ||
7741 | + /* We keep this list in LRU order. */ | ||
7742 | + if ((rdstate->access + RDCACHE_JIFFIES) > jiffies) | ||
7743 | + break; | ||
7744 | + UNIONFS_I(inode)->rdcount--; | ||
7745 | + list_del(&rdstate->cache); | ||
7746 | + free_rdstate(rdstate); | ||
7747 | + } | ||
7748 | + spin_unlock(&UNIONFS_I(inode)->rdlock); | ||
7749 | + | ||
7750 | + return 0; | ||
7751 | +} | ||
7752 | + | ||
7753 | +/* | ||
7754 | + * Used only in nfs, to kill any pending RPC tasks, so that subsequent | ||
7755 | + * code can actually succeed and won't leave tasks that need handling. | ||
7756 | + */ | ||
7757 | +static void unionfs_umount_begin(struct vfsmount *mnt, int flags) | ||
7758 | +{ | ||
7759 | + struct super_block *sb, *hidden_sb; | ||
7760 | + struct vfsmount *hidden_mnt; | ||
7761 | + int bindex, bstart, bend; | ||
7762 | + | ||
7763 | + if (!(flags & MNT_FORCE)) | ||
7764 | + /* we are not being MNT_FORCEd, therefore we should emulate | ||
7765 | + * old behaviour | ||
7766 | + */ | ||
7767 | + return; | ||
7768 | + | ||
7769 | + sb = mnt->mnt_sb; | ||
7770 | + | ||
7771 | + bstart = sbstart(sb); | ||
7772 | + bend = sbend(sb); | ||
7773 | + for (bindex = bstart; bindex <= bend; bindex++) { | ||
7774 | + hidden_mnt = unionfs_lower_mnt_idx(sb->s_root, bindex); | ||
7775 | + unionfs_read_lock(sb); | ||
7776 | + hidden_sb = unionfs_lower_super_idx(sb, bindex); | ||
7777 | + unionfs_read_unlock(sb); | ||
7778 | + | ||
7779 | + if (hidden_mnt && hidden_sb && hidden_sb->s_op && | ||
7780 | + hidden_sb->s_op->umount_begin) | ||
7781 | + hidden_sb->s_op->umount_begin(hidden_mnt, flags); | ||
7782 | + } | ||
7783 | +} | ||
7784 | + | ||
7785 | +static int unionfs_show_options(struct seq_file *m, struct vfsmount *mnt) | ||
7786 | +{ | ||
7787 | + struct super_block *sb = mnt->mnt_sb; | ||
7788 | + int ret = 0; | ||
7789 | + char *tmp_page; | ||
7790 | + char *path; | ||
7791 | + int bindex, bstart, bend; | ||
7792 | + int perms; | ||
7793 | + | ||
7794 | + unionfs_lock_dentry(sb->s_root); | ||
7795 | + | ||
7796 | + tmp_page = (char*) __get_free_page(GFP_KERNEL); | ||
7797 | + if (!tmp_page) { | ||
7798 | + ret = -ENOMEM; | ||
7799 | + goto out; | ||
7800 | + } | ||
7801 | + | ||
7802 | + bstart = sbstart(sb); | ||
7803 | + bend = sbend(sb); | ||
7804 | + | ||
7805 | + seq_printf(m, ",dirs="); | ||
7806 | + for (bindex = bstart; bindex <= bend; bindex++) { | ||
7807 | + path = d_path(unionfs_lower_dentry_idx(sb->s_root, bindex), | ||
7808 | + unionfs_lower_mnt_idx(sb->s_root, bindex), tmp_page, | ||
7809 | + PAGE_SIZE); | ||
7810 | + if (IS_ERR(path)) { | ||
7811 | + ret = PTR_ERR(path); | ||
7812 | + goto out; | ||
7813 | + } | ||
7814 | + | ||
7815 | + unionfs_read_lock(sb); | ||
7816 | + perms = branchperms(sb, bindex); | ||
7817 | + unionfs_read_unlock(sb); | ||
7818 | + | ||
7819 | + seq_printf(m, "%s=%s", path, | ||
7820 | + perms & MAY_WRITE ? "rw" : "ro"); | ||
7821 | + if (bindex != bend) | ||
7822 | + seq_printf(m, ":"); | ||
7823 | + } | ||
7824 | + | ||
7825 | +out: | ||
7826 | + free_page((unsigned long) tmp_page); | ||
7827 | + | ||
7828 | + unionfs_unlock_dentry(sb->s_root); | ||
7829 | + | ||
7830 | + return ret; | ||
7831 | +} | ||
7832 | + | ||
7833 | +struct super_operations unionfs_sops = { | ||
7834 | + .read_inode = unionfs_read_inode, | ||
7835 | + .put_inode = unionfs_put_inode, | ||
7836 | + .delete_inode = unionfs_delete_inode, | ||
7837 | + .put_super = unionfs_put_super, | ||
7838 | + .statfs = unionfs_statfs, | ||
7839 | + .remount_fs = unionfs_remount_fs, | ||
7840 | + .clear_inode = unionfs_clear_inode, | ||
7841 | + .umount_begin = unionfs_umount_begin, | ||
7842 | + .show_options = unionfs_show_options, | ||
7843 | + .write_inode = unionfs_write_inode, | ||
7844 | + .alloc_inode = unionfs_alloc_inode, | ||
7845 | + .destroy_inode = unionfs_destroy_inode, | ||
7846 | +}; | ||
7847 | + | ||
7848 | diff --git a/fs/unionfs/union.h b/fs/unionfs/union.h | ||
7849 | new file mode 100644 | ||
7850 | index 0000000..b6fa0a2 | ||
7851 | --- /dev/null | ||
7852 | +++ b/fs/unionfs/union.h | ||
7853 | @@ -0,0 +1,489 @@ | ||
7854 | +/* | ||
7855 | + * Copyright (c) 2003-2007 Erez Zadok | ||
7856 | + * Copyright (c) 2003-2006 Charles P. Wright | ||
7857 | + * Copyright (c) 2005-2007 Josef 'Jeff' Sipek | ||
7858 | + * Copyright (c) 2005 Arun M. Krishnakumar | ||
7859 | + * Copyright (c) 2004-2006 David P. Quigley | ||
7860 | + * Copyright (c) 2003-2004 Mohammad Nayyer Zubair | ||
7861 | + * Copyright (c) 2003 Puja Gupta | ||
7862 | + * Copyright (c) 2003 Harikesavan Krishnan | ||
7863 | + * Copyright (c) 2003-2007 Stony Brook University | ||
7864 | + * Copyright (c) 2003-2007 The Research Foundation of State University of New York | ||
7865 | + * | ||
7866 | + * This program is free software; you can redistribute it and/or modify | ||
7867 | + * it under the terms of the GNU General Public License version 2 as | ||
7868 | + * published by the Free Software Foundation. | ||
7869 | + */ | ||
7870 | + | ||
7871 | +#ifndef _UNION_H_ | ||
7872 | +#define _UNION_H_ | ||
7873 | + | ||
7874 | +#include <linux/dcache.h> | ||
7875 | +#include <linux/file.h> | ||
7876 | +#include <linux/list.h> | ||
7877 | +#include <linux/fs.h> | ||
7878 | +#include <linux/mm.h> | ||
7879 | +#include <linux/module.h> | ||
7880 | +#include <linux/mount.h> | ||
7881 | +#include <linux/namei.h> | ||
7882 | +#include <linux/page-flags.h> | ||
7883 | +#include <linux/pagemap.h> | ||
7884 | +#include <linux/poll.h> | ||
7885 | +#include <linux/security.h> | ||
7886 | +#include <linux/seq_file.h> | ||
7887 | +#include <linux/slab.h> | ||
7888 | +#include <linux/spinlock.h> | ||
7889 | +#include <linux/smp_lock.h> | ||
7890 | +#include <linux/statfs.h> | ||
7891 | +#include <linux/string.h> | ||
7892 | +#include <linux/vmalloc.h> | ||
7893 | +#include <linux/writeback.h> | ||
7894 | +#include <linux/xattr.h> | ||
7895 | +#include <linux/fs_stack.h> | ||
7896 | +#include <linux/magic.h> | ||
7897 | +#include <linux/log2.h> | ||
7898 | + | ||
7899 | +#include <asm/mman.h> | ||
7900 | +#include <asm/system.h> | ||
7901 | + | ||
7902 | +#include <linux/union_fs.h> | ||
7903 | + | ||
7904 | +/* the file system name */ | ||
7905 | +#define UNIONFS_NAME "unionfs" | ||
7906 | + | ||
7907 | +/* unionfs root inode number */ | ||
7908 | +#define UNIONFS_ROOT_INO 1 | ||
7909 | + | ||
7910 | +/* number of characters while generating unique temporary file names */ | ||
7911 | +#define UNIONFS_TMPNAM_LEN 12 | ||
7912 | + | ||
7913 | +/* number of times we try to get a unique temporary file name */ | ||
7914 | +#define GET_TMPNAM_MAX_RETRY 5 | ||
7915 | + | ||
7916 | +/* maximum number of branches we support, to avoid memory blowup */ | ||
7917 | +#define UNIONFS_MAX_BRANCHES 128 | ||
7918 | + | ||
7919 | +/* Operations vectors defined in specific files. */ | ||
7920 | +extern struct file_operations unionfs_main_fops; | ||
7921 | +extern struct file_operations unionfs_dir_fops; | ||
7922 | +extern struct inode_operations unionfs_main_iops; | ||
7923 | +extern struct inode_operations unionfs_dir_iops; | ||
7924 | +extern struct inode_operations unionfs_symlink_iops; | ||
7925 | +extern struct super_operations unionfs_sops; | ||
7926 | +extern struct dentry_operations unionfs_dops; | ||
7927 | + | ||
7928 | +/* How long should an entry be allowed to persist */ | ||
7929 | +#define RDCACHE_JIFFIES (5*HZ) | ||
7930 | + | ||
7931 | +/* file private data. */ | ||
7932 | +struct unionfs_file_info { | ||
7933 | + int bstart; | ||
7934 | + int bend; | ||
7935 | + atomic_t generation; | ||
7936 | + | ||
7937 | + struct unionfs_dir_state *rdstate; | ||
7938 | + struct file **lower_files; | ||
7939 | + int *saved_branch_ids; /* IDs of branches when file was opened */ | ||
7940 | +}; | ||
7941 | + | ||
7942 | +/* unionfs inode data in memory */ | ||
7943 | +struct unionfs_inode_info { | ||
7944 | + int bstart; | ||
7945 | + int bend; | ||
7946 | + atomic_t generation; | ||
7947 | + int stale; | ||
7948 | + /* Stuff for readdir over NFS. */ | ||
7949 | + spinlock_t rdlock; | ||
7950 | + struct list_head readdircache; | ||
7951 | + int rdcount; | ||
7952 | + int hashsize; | ||
7953 | + int cookie; | ||
7954 | + | ||
7955 | + /* The hidden inodes */ | ||
7956 | + struct inode **lower_inodes; | ||
7957 | + /* to keep track of reads/writes for unlinks before closes */ | ||
7958 | + atomic_t totalopens; | ||
7959 | + | ||
7960 | + struct inode vfs_inode; | ||
7961 | +}; | ||
7962 | + | ||
7963 | +/* unionfs dentry data in memory */ | ||
7964 | +struct unionfs_dentry_info { | ||
7965 | + /* The semaphore is used to lock the dentry as soon as we get into a | ||
7966 | + * unionfs function from the VFS. Our lock ordering is that children | ||
7967 | + * go before their parents. | ||
7968 | + */ | ||
7969 | + struct mutex lock; | ||
7970 | + int bstart; | ||
7971 | + int bend; | ||
7972 | + int bopaque; | ||
7973 | + int bcount; | ||
7974 | + atomic_t generation; | ||
7975 | + struct path *lower_paths; | ||
7976 | +}; | ||
7977 | + | ||
7978 | +/* These are the pointers to our various objects. */ | ||
7979 | +struct unionfs_data { | ||
7980 | + struct super_block *sb; | ||
7981 | + atomic_t open_files; /* number of open files on branch */ | ||
7982 | + int branchperms; | ||
7983 | + int branch_id; /* unique branch ID at re/mount time */ | ||
7984 | +}; | ||
7985 | + | ||
7986 | +/* unionfs super-block data in memory */ | ||
7987 | +struct unionfs_sb_info { | ||
7988 | + int bend; | ||
7989 | + | ||
7990 | + atomic_t generation; | ||
7991 | + struct rw_semaphore rwsem; /* protects access to data+id fields */ | ||
7992 | + int high_branch_id; /* last unique branch ID given */ | ||
7993 | + struct unionfs_data *data; | ||
7994 | +}; | ||
7995 | + | ||
7996 | +/* | ||
7997 | + * structure for making the linked list of entries by readdir on left branch | ||
7998 | + * to compare with entries on right branch | ||
7999 | + */ | ||
8000 | +struct filldir_node { | ||
8001 | + struct list_head file_list; /* list for directory entries */ | ||
8002 | + char *name; /* name entry */ | ||
8003 | + int hash; /* name hash */ | ||
8004 | + int namelen; /* name len since name is not 0 terminated */ | ||
8005 | + | ||
8006 | + /* we can check for duplicate whiteouts and files in the same branch | ||
8007 | + * in order to return -EIO. | ||
8008 | + */ | ||
8009 | + int bindex; | ||
8010 | + | ||
8011 | + /* is this a whiteout entry? */ | ||
8012 | + int whiteout; | ||
8013 | + | ||
8014 | + /* Inline name, so we don't need to separately kmalloc small ones */ | ||
8015 | + char iname[DNAME_INLINE_LEN_MIN]; | ||
8016 | +}; | ||
8017 | + | ||
8018 | +/* Directory hash table. */ | ||
8019 | +struct unionfs_dir_state { | ||
8020 | + unsigned int cookie; /* The cookie, which is based off of rdversion */ | ||
8021 | + unsigned int offset; /* The entry we have returned. */ | ||
8022 | + int bindex; | ||
8023 | + loff_t dirpos; /* The offset within the lower level directory. */ | ||
8024 | + int size; /* How big is the hash table? */ | ||
8025 | + int hashentries; /* How many entries have been inserted? */ | ||
8026 | + unsigned long access; | ||
8027 | + | ||
8028 | + /* This cache list is used when the inode keeps us around. */ | ||
8029 | + struct list_head cache; | ||
8030 | + struct list_head list[0]; | ||
8031 | +}; | ||
8032 | + | ||
8033 | +/* include miscellaneous macros */ | ||
8034 | +#include "fanout.h" | ||
8035 | +#include "sioq.h" | ||
8036 | + | ||
8037 | +/* Cache creation/deletion routines. */ | ||
8038 | +void unionfs_destroy_filldir_cache(void); | ||
8039 | +int unionfs_init_filldir_cache(void); | ||
8040 | +int unionfs_init_inode_cache(void); | ||
8041 | +void unionfs_destroy_inode_cache(void); | ||
8042 | +int unionfs_init_dentry_cache(void); | ||
8043 | +void unionfs_destroy_dentry_cache(void); | ||
8044 | + | ||
8045 | +/* Initialize and free readdir-specific state. */ | ||
8046 | +int init_rdstate(struct file *file); | ||
8047 | +struct unionfs_dir_state *alloc_rdstate(struct inode *inode, int bindex); | ||
8048 | +struct unionfs_dir_state *find_rdstate(struct inode *inode, loff_t fpos); | ||
8049 | +void free_rdstate(struct unionfs_dir_state *state); | ||
8050 | +int add_filldir_node(struct unionfs_dir_state *rdstate, const char *name, | ||
8051 | + int namelen, int bindex, int whiteout); | ||
8052 | +struct filldir_node *find_filldir_node(struct unionfs_dir_state *rdstate, | ||
8053 | + const char *name, int namelen); | ||
8054 | + | ||
8055 | +struct dentry **alloc_new_dentries(int objs); | ||
8056 | +struct unionfs_data *alloc_new_data(int objs); | ||
8057 | + | ||
8058 | +/* We can only use 32-bits of offset for rdstate --- blech! */ | ||
8059 | +#define DIREOF (0xfffff) | ||
8060 | +#define RDOFFBITS 20 /* This is the number of bits in DIREOF. */ | ||
8061 | +#define MAXRDCOOKIE (0xfff) | ||
8062 | +/* Turn an rdstate into an offset. */ | ||
8063 | +static inline off_t rdstate2offset(struct unionfs_dir_state *buf) | ||
8064 | +{ | ||
8065 | + off_t tmp; | ||
8066 | + tmp = ((buf->cookie & MAXRDCOOKIE) << RDOFFBITS) | ||
8067 | + | (buf->offset & DIREOF); | ||
8068 | + return tmp; | ||
8069 | +} | ||
8070 | + | ||
8071 | +#define unionfs_read_lock(sb) down_read(&UNIONFS_SB(sb)->rwsem) | ||
8072 | +#define unionfs_read_unlock(sb) up_read(&UNIONFS_SB(sb)->rwsem) | ||
8073 | +#define unionfs_write_lock(sb) down_write(&UNIONFS_SB(sb)->rwsem) | ||
8074 | +#define unionfs_write_unlock(sb) up_write(&UNIONFS_SB(sb)->rwsem) | ||
8075 | + | ||
8076 | +static inline void double_lock_dentry(struct dentry *d1, struct dentry *d2) | ||
8077 | +{ | ||
8078 | + if (d2 < d1) { | ||
8079 | + struct dentry *tmp = d1; | ||
8080 | + d1 = d2; | ||
8081 | + d2 = tmp; | ||
8082 | + } | ||
8083 | + unionfs_lock_dentry(d1); | ||
8084 | + unionfs_lock_dentry(d2); | ||
8085 | +} | ||
8086 | + | ||
8087 | +extern int new_dentry_private_data(struct dentry *dentry); | ||
8088 | +void free_dentry_private_data(struct unionfs_dentry_info *udi); | ||
8089 | +void update_bstart(struct dentry *dentry); | ||
8090 | + | ||
8091 | +/* | ||
8092 | + * EXTERNALS: | ||
8093 | + */ | ||
8094 | + | ||
8095 | +/* replicates the directory structure upto given dentry in given branch */ | ||
8096 | +extern struct dentry *create_parents(struct inode *dir, struct dentry *dentry, | ||
8097 | + int bindex); | ||
8098 | + | ||
8099 | +/* partial lookup */ | ||
8100 | +extern int unionfs_partial_lookup(struct dentry *dentry); | ||
8101 | + | ||
8102 | +/* Pass an unionfs dentry and an index and it will try to create a whiteout | ||
8103 | + * in branch 'index'. | ||
8104 | + * | ||
8105 | + * On error, it will proceed to a branch to the left | ||
8106 | + */ | ||
8107 | +extern int create_whiteout(struct dentry *dentry, int start); | ||
8108 | +/* copies a file from dbstart to newbindex branch */ | ||
8109 | +extern int copyup_file(struct inode *dir, struct file *file, int bstart, | ||
8110 | + int newbindex, loff_t size); | ||
8111 | +extern int copyup_named_file(struct inode *dir, struct file *file, | ||
8112 | + char *name, int bstart, int new_bindex, | ||
8113 | + loff_t len); | ||
8114 | +/* copies a dentry from dbstart to newbindex branch */ | ||
8115 | +extern int copyup_dentry(struct inode *dir, struct dentry *dentry, int bstart, | ||
8116 | + int new_bindex, struct file **copyup_file, loff_t len); | ||
8117 | + | ||
8118 | +extern int remove_whiteouts(struct dentry *dentry, struct dentry *hidden_dentry, | ||
8119 | + int bindex); | ||
8120 | + | ||
8121 | +extern int do_delete_whiteouts(struct dentry *dentry, int bindex, | ||
8122 | + struct unionfs_dir_state *namelist); | ||
8123 | + | ||
8124 | +extern int unionfs_get_nlinks(struct inode *inode); | ||
8125 | + | ||
8126 | +/* Is this directory empty: 0 if it is empty, -ENOTEMPTY if not. */ | ||
8127 | +extern int check_empty(struct dentry *dentry, | ||
8128 | + struct unionfs_dir_state **namelist); | ||
8129 | +/* Delete whiteouts from this directory in branch bindex. */ | ||
8130 | +extern int delete_whiteouts(struct dentry *dentry, int bindex, | ||
8131 | + struct unionfs_dir_state *namelist); | ||
8132 | + | ||
8133 | +/* Re-lookup a hidden dentry. */ | ||
8134 | +extern int unionfs_refresh_hidden_dentry(struct dentry *dentry, int bindex); | ||
8135 | + | ||
8136 | +extern void unionfs_reinterpose(struct dentry *this_dentry); | ||
8137 | +extern struct super_block *unionfs_duplicate_super(struct super_block *sb); | ||
8138 | + | ||
8139 | +/* Locking functions. */ | ||
8140 | +extern int unionfs_setlk(struct file *file, int cmd, struct file_lock *fl); | ||
8141 | +extern int unionfs_getlk(struct file *file, struct file_lock *fl); | ||
8142 | + | ||
8143 | +/* Common file operations. */ | ||
8144 | +extern int unionfs_file_revalidate(struct file *file, int willwrite); | ||
8145 | +extern int unionfs_open(struct inode *inode, struct file *file); | ||
8146 | +extern int unionfs_file_release(struct inode *inode, struct file *file); | ||
8147 | +extern int unionfs_flush(struct file *file, fl_owner_t id); | ||
8148 | +extern long unionfs_ioctl(struct file *file, unsigned int cmd, | ||
8149 | + unsigned long arg); | ||
8150 | + | ||
8151 | +/* Inode operations */ | ||
8152 | +extern int unionfs_rename(struct inode *old_dir, struct dentry *old_dentry, | ||
8153 | + struct inode *new_dir, struct dentry *new_dentry); | ||
8154 | +int unionfs_unlink(struct inode *dir, struct dentry *dentry); | ||
8155 | +int unionfs_rmdir(struct inode *dir, struct dentry *dentry); | ||
8156 | + | ||
8157 | +int __unionfs_d_revalidate_chain(struct dentry *dentry, struct nameidata *nd); | ||
8158 | + | ||
8159 | +/* The values for unionfs_interpose's flag. */ | ||
8160 | +#define INTERPOSE_DEFAULT 0 | ||
8161 | +#define INTERPOSE_LOOKUP 1 | ||
8162 | +#define INTERPOSE_REVAL 2 | ||
8163 | +#define INTERPOSE_REVAL_NEG 3 | ||
8164 | +#define INTERPOSE_PARTIAL 4 | ||
8165 | + | ||
8166 | +extern int unionfs_interpose(struct dentry *this_dentry, struct super_block *sb, | ||
8167 | + int flag); | ||
8168 | + | ||
8169 | +/* Branch management ioctls. */ | ||
8170 | +int unionfs_ioctl_incgen(struct file *file, unsigned int cmd, | ||
8171 | + unsigned long arg); | ||
8172 | +int unionfs_ioctl_queryfile(struct file *file, unsigned int cmd, | ||
8173 | + unsigned long arg); | ||
8174 | + | ||
8175 | +#ifdef CONFIG_UNION_FS_XATTR | ||
8176 | +/* Extended attribute functions. */ | ||
8177 | +extern void *unionfs_xattr_alloc(size_t size, size_t limit); | ||
8178 | +extern void unionfs_xattr_free(void *ptr, size_t size); | ||
8179 | + | ||
8180 | +extern ssize_t unionfs_getxattr(struct dentry *dentry, const char *name, | ||
8181 | + void *value, size_t size); | ||
8182 | +extern int unionfs_removexattr(struct dentry *dentry, const char *name); | ||
8183 | +extern ssize_t unionfs_listxattr(struct dentry *dentry, char *list, | ||
8184 | + size_t size); | ||
8185 | +extern int unionfs_setxattr(struct dentry *dentry, const char *name, | ||
8186 | + const void *value, size_t size, int flags); | ||
8187 | +#endif /* CONFIG_UNION_FS_XATTR */ | ||
8188 | + | ||
8189 | +/* The root directory is unhashed, but isn't deleted. */ | ||
8190 | +static inline int d_deleted(struct dentry *d) | ||
8191 | +{ | ||
8192 | + return d_unhashed(d) && (d != d->d_sb->s_root); | ||
8193 | +} | ||
8194 | + | ||
8195 | +struct dentry *unionfs_lookup_backend(struct dentry *dentry, struct nameidata *nd, int lookupmode); | ||
8196 | + | ||
8197 | +/* unionfs_permission, check if we should bypass error to facilitate copyup */ | ||
8198 | +#define IS_COPYUP_ERR(err) ((err) == -EROFS) | ||
8199 | + | ||
8200 | +/* unionfs_open, check if we need to copyup the file */ | ||
8201 | +#define OPEN_WRITE_FLAGS (O_WRONLY | O_RDWR | O_APPEND) | ||
8202 | +#define IS_WRITE_FLAG(flag) ((flag) & OPEN_WRITE_FLAGS) | ||
8203 | + | ||
8204 | +static inline int branchperms(const struct super_block *sb, int index) | ||
8205 | +{ | ||
8206 | + BUG_ON(index < 0); | ||
8207 | + | ||
8208 | + return UNIONFS_SB(sb)->data[index].branchperms; | ||
8209 | +} | ||
8210 | + | ||
8211 | +static inline int set_branchperms(struct super_block *sb, int index, int perms) | ||
8212 | +{ | ||
8213 | + BUG_ON(index < 0); | ||
8214 | + | ||
8215 | + UNIONFS_SB(sb)->data[index].branchperms = perms; | ||
8216 | + | ||
8217 | + return perms; | ||
8218 | +} | ||
8219 | + | ||
8220 | +/* Is this file on a read-only branch? */ | ||
8221 | +static inline int is_robranch_super(const struct super_block *sb, int index) | ||
8222 | +{ | ||
8223 | + int ret; | ||
8224 | + unionfs_read_lock(sb); | ||
8225 | + ret = (!(branchperms(sb, index) & MAY_WRITE)) ? -EROFS : 0; | ||
8226 | + unionfs_read_unlock(sb); | ||
8227 | + return ret; | ||
8228 | +} | ||
8229 | + | ||
8230 | +/* Is this file on a read-only branch? */ | ||
8231 | +static inline int is_robranch_idx(const struct dentry *dentry, int index) | ||
8232 | +{ | ||
8233 | + int err = 0; | ||
8234 | + | ||
8235 | + BUG_ON(index < 0); | ||
8236 | + | ||
8237 | + unionfs_read_lock(dentry->d_sb); | ||
8238 | + if ((!(branchperms(dentry->d_sb, index) & MAY_WRITE)) || | ||
8239 | + IS_RDONLY(unionfs_lower_dentry_idx(dentry, index)->d_inode)) | ||
8240 | + err = -EROFS; | ||
8241 | + unionfs_read_unlock(dentry->d_sb); | ||
8242 | + return err; | ||
8243 | +} | ||
8244 | + | ||
8245 | +static inline int is_robranch(const struct dentry *dentry) | ||
8246 | +{ | ||
8247 | + int index; | ||
8248 | + | ||
8249 | + index = UNIONFS_D(dentry)->bstart; | ||
8250 | + BUG_ON(index < 0); | ||
8251 | + | ||
8252 | + return is_robranch_idx(dentry, index); | ||
8253 | +} | ||
8254 | + | ||
8255 | +/* | ||
8256 | + * Check if dentry is valid or not, as per our generation numbers. | ||
8257 | + * @dentry: dentry to check. | ||
8258 | + * Returns 1 (valid) or 0 (invalid/stale). | ||
8259 | + */ | ||
8260 | +static inline int is_valid_dentry(struct dentry *dentry) | ||
8261 | +{ | ||
8262 | + BUG_ON(!UNIONFS_D(dentry)); | ||
8263 | + BUG_ON(!UNIONFS_SB(dentry->d_sb)); | ||
8264 | + return (atomic_read(&UNIONFS_D(dentry)->generation) == | ||
8265 | + atomic_read(&UNIONFS_SB(dentry->d_sb)->generation)); | ||
8266 | +} | ||
8267 | + | ||
8268 | +/* What do we use for whiteouts. */ | ||
8269 | +#define UNIONFS_WHPFX ".wh." | ||
8270 | +#define UNIONFS_WHLEN 4 | ||
8271 | +/* If a directory contains this file, then it is opaque. We start with the | ||
8272 | + * .wh. flag so that it is blocked by lookup. | ||
8273 | + */ | ||
8274 | +#define UNIONFS_DIR_OPAQUE_NAME "__dir_opaque" | ||
8275 | +#define UNIONFS_DIR_OPAQUE UNIONFS_WHPFX UNIONFS_DIR_OPAQUE_NAME | ||
8276 | + | ||
8277 | +#ifndef DEFAULT_POLLMASK | ||
8278 | +#define DEFAULT_POLLMASK (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM) | ||
8279 | +#endif | ||
8280 | + | ||
8281 | +/* | ||
8282 | + * EXTERNALS: | ||
8283 | + */ | ||
8284 | +extern char *alloc_whname(const char *name, int len); | ||
8285 | +extern int check_branch(struct nameidata *nd); | ||
8286 | +extern int __parse_branch_mode(const char *name); | ||
8287 | +extern int parse_branch_mode(const char *name); | ||
8288 | + | ||
8289 | +/* These two functions are here because it is kind of daft to copy and paste the | ||
8290 | + * contents of the two functions to 32+ places in unionfs | ||
8291 | + */ | ||
8292 | +static inline struct dentry *lock_parent(struct dentry *dentry) | ||
8293 | +{ | ||
8294 | + struct dentry *dir = dget(dentry->d_parent); | ||
8295 | + | ||
8296 | + mutex_lock(&dir->d_inode->i_mutex); | ||
8297 | + return dir; | ||
8298 | +} | ||
8299 | + | ||
8300 | +static inline void unlock_dir(struct dentry *dir) | ||
8301 | +{ | ||
8302 | + mutex_unlock(&dir->d_inode->i_mutex); | ||
8303 | + dput(dir); | ||
8304 | +} | ||
8305 | + | ||
8306 | +extern int make_dir_opaque(struct dentry *dir, int bindex); | ||
8307 | + | ||
8308 | +static inline struct vfsmount *unionfs_mntget(struct dentry *dentry, int bindex) | ||
8309 | +{ | ||
8310 | + struct vfsmount *mnt; | ||
8311 | + if (!dentry) { | ||
8312 | + if (bindex < 0) | ||
8313 | + return NULL; | ||
8314 | + BUG_ON(bindex < 0); | ||
8315 | + } | ||
8316 | + mnt = unionfs_lower_mnt_idx(dentry, bindex); | ||
8317 | + if (!mnt) { | ||
8318 | + if (bindex < 0) | ||
8319 | + return NULL; | ||
8320 | + BUG_ON(mnt && bindex < 0); | ||
8321 | + } | ||
8322 | + mnt = mntget(mnt); | ||
8323 | + return mnt; | ||
8324 | +} | ||
8325 | + | ||
8326 | +static inline void unionfs_mntput(struct dentry *dentry, int bindex) | ||
8327 | +{ | ||
8328 | + struct vfsmount *mnt; | ||
8329 | + if (!dentry) { | ||
8330 | + if (bindex < 0) | ||
8331 | + return; | ||
8332 | + BUG_ON(dentry && bindex < 0); | ||
8333 | + } | ||
8334 | + mnt = unionfs_lower_mnt_idx(dentry, bindex); | ||
8335 | + if (!mnt) { | ||
8336 | + if (bindex < 0) | ||
8337 | + return; | ||
8338 | + BUG_ON(mnt && bindex < 0); | ||
8339 | + } | ||
8340 | + mntput(mnt); | ||
8341 | +} | ||
8342 | +#endif /* not _UNION_H_ */ | ||
8343 | diff --git a/fs/unionfs/unlink.c b/fs/unionfs/unlink.c | ||
8344 | new file mode 100644 | ||
8345 | index 0000000..dd1dd9c | ||
8346 | --- /dev/null | ||
8347 | +++ b/fs/unionfs/unlink.c | ||
8348 | @@ -0,0 +1,166 @@ | ||
8349 | +/* | ||
8350 | + * Copyright (c) 2003-2007 Erez Zadok | ||
8351 | + * Copyright (c) 2003-2006 Charles P. Wright | ||
8352 | + * Copyright (c) 2005-2007 Josef 'Jeff' Sipek | ||
8353 | + * Copyright (c) 2005-2006 Junjiro Okajima | ||
8354 | + * Copyright (c) 2005 Arun M. Krishnakumar | ||
8355 | + * Copyright (c) 2004-2006 David P. Quigley | ||
8356 | + * Copyright (c) 2003-2004 Mohammad Nayyer Zubair | ||
8357 | + * Copyright (c) 2003 Puja Gupta | ||
8358 | + * Copyright (c) 2003 Harikesavan Krishnan | ||
8359 | + * Copyright (c) 2003-2007 Stony Brook University | ||
8360 | + * Copyright (c) 2003-2007 The Research Foundation of State University of New York | ||
8361 | + * | ||
8362 | + * This program is free software; you can redistribute it and/or modify | ||
8363 | + * it under the terms of the GNU General Public License version 2 as | ||
8364 | + * published by the Free Software Foundation. | ||
8365 | + */ | ||
8366 | + | ||
8367 | +#include "union.h" | ||
8368 | + | ||
8369 | +/* unlink a file by creating a whiteout */ | ||
8370 | +static int unionfs_unlink_whiteout(struct inode *dir, struct dentry *dentry) | ||
8371 | +{ | ||
8372 | + struct dentry *hidden_dentry; | ||
8373 | + struct dentry *hidden_dir_dentry; | ||
8374 | + int bindex; | ||
8375 | + int err = 0; | ||
8376 | + | ||
8377 | + if ((err = unionfs_partial_lookup(dentry))) | ||
8378 | + goto out; | ||
8379 | + | ||
8380 | + bindex = dbstart(dentry); | ||
8381 | + | ||
8382 | + hidden_dentry = unionfs_lower_dentry_idx(dentry, bindex); | ||
8383 | + if (!hidden_dentry) | ||
8384 | + goto out; | ||
8385 | + | ||
8386 | + hidden_dir_dentry = lock_parent(hidden_dentry); | ||
8387 | + | ||
8388 | + /* avoid destroying the hidden inode if the file is in use */ | ||
8389 | + dget(hidden_dentry); | ||
8390 | + if (!(err = is_robranch_super(dentry->d_sb, bindex))) | ||
8391 | + err = vfs_unlink(hidden_dir_dentry->d_inode, hidden_dentry); | ||
8392 | + dput(hidden_dentry); | ||
8393 | + fsstack_copy_attr_times(dir, hidden_dir_dentry->d_inode); | ||
8394 | + unlock_dir(hidden_dir_dentry); | ||
8395 | + | ||
8396 | + if (err && !IS_COPYUP_ERR(err)) | ||
8397 | + goto out; | ||
8398 | + | ||
8399 | + if (err) { | ||
8400 | + if (dbstart(dentry) == 0) | ||
8401 | + goto out; | ||
8402 | + | ||
8403 | + err = create_whiteout(dentry, dbstart(dentry) - 1); | ||
8404 | + } else if (dbopaque(dentry) != -1) | ||
8405 | + /* There is a hidden lower-priority file with the same name. */ | ||
8406 | + err = create_whiteout(dentry, dbopaque(dentry)); | ||
8407 | + else | ||
8408 | + err = create_whiteout(dentry, dbstart(dentry)); | ||
8409 | + | ||
8410 | +out: | ||
8411 | + if (!err) | ||
8412 | + dentry->d_inode->i_nlink--; | ||
8413 | + | ||
8414 | + /* We don't want to leave negative leftover dentries for revalidate. */ | ||
8415 | + if (!err && (dbopaque(dentry) != -1)) | ||
8416 | + update_bstart(dentry); | ||
8417 | + | ||
8418 | + return err; | ||
8419 | +} | ||
8420 | + | ||
8421 | +int unionfs_unlink(struct inode *dir, struct dentry *dentry) | ||
8422 | +{ | ||
8423 | + int err = 0; | ||
8424 | + | ||
8425 | + BUG_ON(!is_valid_dentry(dentry)); | ||
8426 | + | ||
8427 | + unionfs_lock_dentry(dentry); | ||
8428 | + | ||
8429 | + err = unionfs_unlink_whiteout(dir, dentry); | ||
8430 | + /* call d_drop so the system "forgets" about us */ | ||
8431 | + if (!err) | ||
8432 | + d_drop(dentry); | ||
8433 | + | ||
8434 | + unionfs_unlock_dentry(dentry); | ||
8435 | + return err; | ||
8436 | +} | ||
8437 | + | ||
8438 | +static int unionfs_rmdir_first(struct inode *dir, struct dentry *dentry, | ||
8439 | + struct unionfs_dir_state *namelist) | ||
8440 | +{ | ||
8441 | + int err; | ||
8442 | + struct dentry *hidden_dentry; | ||
8443 | + struct dentry *hidden_dir_dentry = NULL; | ||
8444 | + | ||
8445 | + /* Here we need to remove whiteout entries. */ | ||
8446 | + err = delete_whiteouts(dentry, dbstart(dentry), namelist); | ||
8447 | + if (err) | ||
8448 | + goto out; | ||
8449 | + | ||
8450 | + hidden_dentry = unionfs_lower_dentry(dentry); | ||
8451 | + | ||
8452 | + hidden_dir_dentry = lock_parent(hidden_dentry); | ||
8453 | + | ||
8454 | + /* avoid destroying the hidden inode if the file is in use */ | ||
8455 | + dget(hidden_dentry); | ||
8456 | + if (!(err = is_robranch(dentry))) | ||
8457 | + err = vfs_rmdir(hidden_dir_dentry->d_inode, hidden_dentry); | ||
8458 | + dput(hidden_dentry); | ||
8459 | + | ||
8460 | + fsstack_copy_attr_times(dir, hidden_dir_dentry->d_inode); | ||
8461 | + /* propagate number of hard-links */ | ||
8462 | + dentry->d_inode->i_nlink = unionfs_get_nlinks(dentry->d_inode); | ||
8463 | + | ||
8464 | +out: | ||
8465 | + if (hidden_dir_dentry) | ||
8466 | + unlock_dir(hidden_dir_dentry); | ||
8467 | + return err; | ||
8468 | +} | ||
8469 | + | ||
8470 | +int unionfs_rmdir(struct inode *dir, struct dentry *dentry) | ||
8471 | +{ | ||
8472 | + int err = 0; | ||
8473 | + struct unionfs_dir_state *namelist = NULL; | ||
8474 | + | ||
8475 | + BUG_ON(!is_valid_dentry(dentry)); | ||
8476 | + | ||
8477 | + unionfs_lock_dentry(dentry); | ||
8478 | + | ||
8479 | + /* check if this unionfs directory is empty or not */ | ||
8480 | + err = check_empty(dentry, &namelist); | ||
8481 | + if (err) | ||
8482 | + goto out; | ||
8483 | + | ||
8484 | + err = unionfs_rmdir_first(dir, dentry, namelist); | ||
8485 | + /* create whiteout */ | ||
8486 | + if (!err) | ||
8487 | + err = create_whiteout(dentry, dbstart(dentry)); | ||
8488 | + else { | ||
8489 | + int new_err; | ||
8490 | + | ||
8491 | + if (dbstart(dentry) == 0) | ||
8492 | + goto out; | ||
8493 | + | ||
8494 | + /* exit if the error returned was NOT -EROFS */ | ||
8495 | + if (!IS_COPYUP_ERR(err)) | ||
8496 | + goto out; | ||
8497 | + | ||
8498 | + new_err = create_whiteout(dentry, dbstart(dentry) - 1); | ||
8499 | + if (new_err != -EEXIST) | ||
8500 | + err = new_err; | ||
8501 | + } | ||
8502 | + | ||
8503 | +out: | ||
8504 | + /* call d_drop so the system "forgets" about us */ | ||
8505 | + if (!err) | ||
8506 | + d_drop(dentry); | ||
8507 | + | ||
8508 | + if (namelist) | ||
8509 | + free_rdstate(namelist); | ||
8510 | + | ||
8511 | + unionfs_unlock_dentry(dentry); | ||
8512 | + return err; | ||
8513 | +} | ||
8514 | + | ||
8515 | diff --git a/fs/unionfs/xattr.c b/fs/unionfs/xattr.c | ||
8516 | new file mode 100644 | ||
8517 | index 0000000..6e1f4bd | ||
8518 | --- /dev/null | ||
8519 | +++ b/fs/unionfs/xattr.c | ||
8520 | @@ -0,0 +1,131 @@ | ||
8521 | +/* | ||
8522 | + * Copyright (c) 2003-2007 Erez Zadok | ||
8523 | + * Copyright (c) 2003-2006 Charles P. Wright | ||
8524 | + * Copyright (c) 2005-2007 Josef 'Jeff' Sipek | ||
8525 | + * Copyright (c) 2005-2006 Junjiro Okajima | ||
8526 | + * Copyright (c) 2005 Arun M. Krishnakumar | ||
8527 | + * Copyright (c) 2004-2006 David P. Quigley | ||
8528 | + * Copyright (c) 2003-2004 Mohammad Nayyer Zubair | ||
8529 | + * Copyright (c) 2003 Puja Gupta | ||
8530 | + * Copyright (c) 2003 Harikesavan Krishnan | ||
8531 | + * Copyright (c) 2003-2007 Stony Brook University | ||
8532 | + * Copyright (c) 2003-2007 The Research Foundation of State University of New York* | ||
8533 | + * | ||
8534 | + * This program is free software; you can redistribute it and/or modify | ||
8535 | + * it under the terms of the GNU General Public License version 2 as | ||
8536 | + * published by the Free Software Foundation. | ||
8537 | + */ | ||
8538 | + | ||
8539 | +#include "union.h" | ||
8540 | + | ||
8541 | +/* This is lifted from fs/xattr.c */ | ||
8542 | +void *unionfs_xattr_alloc(size_t size, size_t limit) | ||
8543 | +{ | ||
8544 | + void *ptr; | ||
8545 | + | ||
8546 | + if (size > limit) | ||
8547 | + return ERR_PTR(-E2BIG); | ||
8548 | + | ||
8549 | + if (!size) /* size request, no buffer is needed */ | ||
8550 | + return NULL; | ||
8551 | + else if (size <= PAGE_SIZE) | ||
8552 | + ptr = kmalloc(size, GFP_KERNEL); | ||
8553 | + else | ||
8554 | + ptr = vmalloc(size); | ||
8555 | + if (!ptr) | ||
8556 | + return ERR_PTR(-ENOMEM); | ||
8557 | + return ptr; | ||
8558 | +} | ||
8559 | + | ||
8560 | +void unionfs_xattr_free(void *ptr, size_t size) | ||
8561 | +{ | ||
8562 | + if (!size) /* size request, no buffer was needed */ | ||
8563 | + return; | ||
8564 | + else if (size <= PAGE_SIZE) | ||
8565 | + kfree(ptr); | ||
8566 | + else | ||
8567 | + vfree(ptr); | ||
8568 | +} | ||
8569 | + | ||
8570 | +/* BKL held by caller. | ||
8571 | + * dentry->d_inode->i_mutex locked | ||
8572 | + */ | ||
8573 | +ssize_t unionfs_getxattr(struct dentry * dentry, const char *name, void *value, | ||
8574 | + size_t size) | ||
8575 | +{ | ||
8576 | + struct dentry *hidden_dentry = NULL; | ||
8577 | + int err = -EOPNOTSUPP; | ||
8578 | + | ||
8579 | + BUG_ON(!is_valid_dentry(dentry)); | ||
8580 | + | ||
8581 | + unionfs_lock_dentry(dentry); | ||
8582 | + | ||
8583 | + hidden_dentry = unionfs_lower_dentry(dentry); | ||
8584 | + | ||
8585 | + err = vfs_getxattr(hidden_dentry, (char*) name, value, size); | ||
8586 | + | ||
8587 | + unionfs_unlock_dentry(dentry); | ||
8588 | + return err; | ||
8589 | +} | ||
8590 | + | ||
8591 | +/* BKL held by caller. | ||
8592 | + * dentry->d_inode->i_mutex locked | ||
8593 | + */ | ||
8594 | +int unionfs_setxattr(struct dentry *dentry, const char *name, const void *value, | ||
8595 | + size_t size, int flags) | ||
8596 | +{ | ||
8597 | + struct dentry *hidden_dentry = NULL; | ||
8598 | + int err = -EOPNOTSUPP; | ||
8599 | + | ||
8600 | + BUG_ON(!is_valid_dentry(dentry)); | ||
8601 | + | ||
8602 | + unionfs_lock_dentry(dentry); | ||
8603 | + hidden_dentry = unionfs_lower_dentry(dentry); | ||
8604 | + | ||
8605 | + err = vfs_setxattr(hidden_dentry, (char*) name, (void*) value, size, flags); | ||
8606 | + | ||
8607 | + unionfs_unlock_dentry(dentry); | ||
8608 | + return err; | ||
8609 | +} | ||
8610 | + | ||
8611 | +/* BKL held by caller. | ||
8612 | + * dentry->d_inode->i_mutex locked | ||
8613 | + */ | ||
8614 | +int unionfs_removexattr(struct dentry *dentry, const char *name) | ||
8615 | +{ | ||
8616 | + struct dentry *hidden_dentry = NULL; | ||
8617 | + int err = -EOPNOTSUPP; | ||
8618 | + | ||
8619 | + BUG_ON(!is_valid_dentry(dentry)); | ||
8620 | + | ||
8621 | + unionfs_lock_dentry(dentry); | ||
8622 | + hidden_dentry = unionfs_lower_dentry(dentry); | ||
8623 | + | ||
8624 | + err = vfs_removexattr(hidden_dentry, (char*) name); | ||
8625 | + | ||
8626 | + unionfs_unlock_dentry(dentry); | ||
8627 | + return err; | ||
8628 | +} | ||
8629 | + | ||
8630 | +/* BKL held by caller. | ||
8631 | + * dentry->d_inode->i_mutex locked | ||
8632 | + */ | ||
8633 | +ssize_t unionfs_listxattr(struct dentry * dentry, char *list, size_t size) | ||
8634 | +{ | ||
8635 | + struct dentry *hidden_dentry = NULL; | ||
8636 | + int err = -EOPNOTSUPP; | ||
8637 | + char *encoded_list = NULL; | ||
8638 | + | ||
8639 | + BUG_ON(!is_valid_dentry(dentry)); | ||
8640 | + | ||
8641 | + unionfs_lock_dentry(dentry); | ||
8642 | + | ||
8643 | + hidden_dentry = unionfs_lower_dentry(dentry); | ||
8644 | + | ||
8645 | + encoded_list = list; | ||
8646 | + err = vfs_listxattr(hidden_dentry, encoded_list, size); | ||
8647 | + | ||
8648 | + unionfs_unlock_dentry(dentry); | ||
8649 | + return err; | ||
8650 | +} | ||
8651 | + | ||
8652 | diff --git a/include/linux/magic.h b/include/linux/magic.h | ||
8653 | index a9c6567..a6751f6 100644 | ||
8654 | --- a/include/linux/magic.h | ||
8655 | +++ b/include/linux/magic.h | ||
8656 | @@ -35,6 +35,8 @@ | ||
8657 | #define REISER2FS_SUPER_MAGIC_STRING "ReIsEr2Fs" | ||
8658 | #define REISER2FS_JR_SUPER_MAGIC_STRING "ReIsEr3Fs" | ||
8659 | |||
8660 | +#define UNIONFS_SUPER_MAGIC 0xf15f083d | ||
8661 | + | ||
8662 | #define SMB_SUPER_MAGIC 0x517B | ||
8663 | #define USBDEVICE_SUPER_MAGIC 0x9fa2 | ||
8664 | |||
8665 | diff --git a/include/linux/mm.h b/include/linux/mm.h | ||
8666 | index 60e0e4a..c680669 100644 | ||
8667 | --- a/include/linux/mm.h | ||
8668 | +++ b/include/linux/mm.h | ||
8669 | @@ -1157,6 +1157,7 @@ int drop_caches_sysctl_handler(struct ctl_table *, int, struct file *, | ||
8670 | void __user *, size_t *, loff_t *); | ||
8671 | unsigned long shrink_slab(unsigned long scanned, gfp_t gfp_mask, | ||
8672 | unsigned long lru_pages); | ||
8673 | +extern void drop_pagecache_sb(struct super_block *); | ||
8674 | void drop_pagecache(void); | ||
8675 | void drop_slab(void); | ||
8676 | |||
8677 | diff --git a/include/linux/namei.h b/include/linux/namei.h | ||
8678 | index d39a5a6..92b422b 100644 | ||
8679 | --- a/include/linux/namei.h | ||
8680 | +++ b/include/linux/namei.h | ||
8681 | @@ -3,6 +3,7 @@ | ||
8682 | |||
8683 | #include <linux/dcache.h> | ||
8684 | #include <linux/linkage.h> | ||
8685 | +#include <linux/mount.h> | ||
8686 | |||
8687 | struct vfsmount; | ||
8688 | |||
8689 | @@ -81,7 +82,15 @@ extern struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry | ||
8690 | extern struct file *nameidata_to_filp(struct nameidata *nd, int flags); | ||
8691 | extern void release_open_intent(struct nameidata *); | ||
8692 | |||
8693 | -extern struct dentry * lookup_one_len(const char *, struct dentry *, int); | ||
8694 | +extern struct dentry *lookup_one_len_nd(const char *, | ||
8695 | + struct dentry *, int, struct nameidata *); | ||
8696 | + | ||
8697 | +/* SMP-safe */ | ||
8698 | +static inline struct dentry *lookup_one_len(const char *name, | ||
8699 | + struct dentry *dir, int len) | ||
8700 | +{ | ||
8701 | + return lookup_one_len_nd(name, dir, len, NULL); | ||
8702 | +} | ||
8703 | |||
8704 | extern int follow_down(struct vfsmount **, struct dentry **); | ||
8705 | extern int follow_up(struct vfsmount **, struct dentry **); | ||
8706 | @@ -99,4 +108,16 @@ static inline char *nd_get_link(struct nameidata *nd) | ||
8707 | return nd->saved_names[nd->depth]; | ||
8708 | } | ||
8709 | |||
8710 | +static inline void pathget(struct path *path) | ||
8711 | +{ | ||
8712 | + mntget(path->mnt); | ||
8713 | + dget(path->dentry); | ||
8714 | +} | ||
8715 | + | ||
8716 | +static inline void pathput(struct path *path) | ||
8717 | +{ | ||
8718 | + dput(path->dentry); | ||
8719 | + mntput(path->mnt); | ||
8720 | +} | ||
8721 | + | ||
8722 | #endif /* _LINUX_NAMEI_H */ | ||
8723 | diff --git a/include/linux/union_fs.h b/include/linux/union_fs.h | ||
8724 | new file mode 100644 | ||
8725 | index 0000000..b724031 | ||
8726 | --- /dev/null | ||
8727 | +++ b/include/linux/union_fs.h | ||
8728 | @@ -0,0 +1,18 @@ | ||
8729 | +#ifndef _LINUX_UNION_FS_H | ||
8730 | +#define _LINUX_UNION_FS_H | ||
8731 | + | ||
8732 | +#define UNIONFS_VERSION "2.0" | ||
8733 | +/* | ||
8734 | + * DEFINITIONS FOR USER AND KERNEL CODE: | ||
8735 | + */ | ||
8736 | +# define UNIONFS_IOCTL_INCGEN _IOR(0x15, 11, int) | ||
8737 | +# define UNIONFS_IOCTL_QUERYFILE _IOR(0x15, 15, int) | ||
8738 | + | ||
8739 | +/* We don't support normal remount, but unionctl uses it. */ | ||
8740 | +# define UNIONFS_REMOUNT_MAGIC 0x4a5a4380 | ||
8741 | + | ||
8742 | +/* should be at least LAST_USED_UNIONFS_PERMISSION<<1 */ | ||
8743 | +#define MAY_NFSRO 16 | ||
8744 | + | ||
8745 | +#endif /* _LINUX_UNIONFS_H */ | ||
8746 | + |