Contents of /trunk/kernel26-magellan/patches-2.6.21-r7/0153-2.6.21-unionfs-2.0-u2.patch
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Sat Jul 21 00:37:57 2007 UTC (17 years, 2 months ago) by niro
File size: 247073 byte(s)
Sat Jul 21 00:37:57 2007 UTC (17 years, 2 months ago) by niro
File size: 247073 byte(s)
2.6.21-magellan-r7
1 | 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 | + |