Contents of /alx-src/tags/kernel26-2.6.12-alx-r9/fs/stat.c
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Wed Mar 4 11:03:09 2009 UTC (15 years, 3 months ago) by niro
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File size: 9413 byte(s)
Wed Mar 4 11:03:09 2009 UTC (15 years, 3 months ago) by niro
File MIME type: text/plain
File size: 9413 byte(s)
Tag kernel26-2.6.12-alx-r9
1 | /* |
2 | * linux/fs/stat.c |
3 | * |
4 | * Copyright (C) 1991, 1992 Linus Torvalds |
5 | */ |
6 | |
7 | #include <linux/config.h> |
8 | #include <linux/module.h> |
9 | #include <linux/mm.h> |
10 | #include <linux/errno.h> |
11 | #include <linux/file.h> |
12 | #include <linux/smp_lock.h> |
13 | #include <linux/highuid.h> |
14 | #include <linux/fs.h> |
15 | #include <linux/namei.h> |
16 | #include <linux/security.h> |
17 | #include <linux/syscalls.h> |
18 | |
19 | #include <asm/uaccess.h> |
20 | #include <asm/unistd.h> |
21 | |
22 | void generic_fillattr(struct inode *inode, struct kstat *stat) |
23 | { |
24 | stat->dev = inode->i_sb->s_dev; |
25 | stat->ino = inode->i_ino; |
26 | stat->mode = inode->i_mode; |
27 | stat->nlink = inode->i_nlink; |
28 | stat->uid = inode->i_uid; |
29 | stat->gid = inode->i_gid; |
30 | stat->rdev = inode->i_rdev; |
31 | stat->atime = inode->i_atime; |
32 | stat->mtime = inode->i_mtime; |
33 | stat->ctime = inode->i_ctime; |
34 | stat->size = i_size_read(inode); |
35 | stat->blocks = inode->i_blocks; |
36 | stat->blksize = inode->i_blksize; |
37 | } |
38 | |
39 | EXPORT_SYMBOL(generic_fillattr); |
40 | |
41 | int vfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) |
42 | { |
43 | struct inode *inode = dentry->d_inode; |
44 | int retval; |
45 | |
46 | retval = security_inode_getattr(mnt, dentry); |
47 | if (retval) |
48 | return retval; |
49 | |
50 | if (inode->i_op->getattr) |
51 | return inode->i_op->getattr(mnt, dentry, stat); |
52 | |
53 | generic_fillattr(inode, stat); |
54 | if (!stat->blksize) { |
55 | struct super_block *s = inode->i_sb; |
56 | unsigned blocks; |
57 | blocks = (stat->size+s->s_blocksize-1) >> s->s_blocksize_bits; |
58 | stat->blocks = (s->s_blocksize / 512) * blocks; |
59 | stat->blksize = s->s_blocksize; |
60 | } |
61 | return 0; |
62 | } |
63 | |
64 | EXPORT_SYMBOL(vfs_getattr); |
65 | |
66 | int vfs_stat(char __user *name, struct kstat *stat) |
67 | { |
68 | struct nameidata nd; |
69 | int error; |
70 | |
71 | error = user_path_walk(name, &nd); |
72 | if (!error) { |
73 | error = vfs_getattr(nd.mnt, nd.dentry, stat); |
74 | path_release(&nd); |
75 | } |
76 | return error; |
77 | } |
78 | |
79 | EXPORT_SYMBOL(vfs_stat); |
80 | |
81 | int vfs_lstat(char __user *name, struct kstat *stat) |
82 | { |
83 | struct nameidata nd; |
84 | int error; |
85 | |
86 | error = user_path_walk_link(name, &nd); |
87 | if (!error) { |
88 | error = vfs_getattr(nd.mnt, nd.dentry, stat); |
89 | path_release(&nd); |
90 | } |
91 | return error; |
92 | } |
93 | |
94 | EXPORT_SYMBOL(vfs_lstat); |
95 | |
96 | int vfs_fstat(unsigned int fd, struct kstat *stat) |
97 | { |
98 | struct file *f = fget(fd); |
99 | int error = -EBADF; |
100 | |
101 | if (f) { |
102 | error = vfs_getattr(f->f_vfsmnt, f->f_dentry, stat); |
103 | fput(f); |
104 | } |
105 | return error; |
106 | } |
107 | |
108 | EXPORT_SYMBOL(vfs_fstat); |
109 | |
110 | #ifdef __ARCH_WANT_OLD_STAT |
111 | |
112 | /* |
113 | * For backward compatibility? Maybe this should be moved |
114 | * into arch/i386 instead? |
115 | */ |
116 | static int cp_old_stat(struct kstat *stat, struct __old_kernel_stat __user * statbuf) |
117 | { |
118 | static int warncount = 5; |
119 | struct __old_kernel_stat tmp; |
120 | |
121 | if (warncount > 0) { |
122 | warncount--; |
123 | printk(KERN_WARNING "VFS: Warning: %s using old stat() call. Recompile your binary.\n", |
124 | current->comm); |
125 | } else if (warncount < 0) { |
126 | /* it's laughable, but... */ |
127 | warncount = 0; |
128 | } |
129 | |
130 | memset(&tmp, 0, sizeof(struct __old_kernel_stat)); |
131 | tmp.st_dev = old_encode_dev(stat->dev); |
132 | tmp.st_ino = stat->ino; |
133 | tmp.st_mode = stat->mode; |
134 | tmp.st_nlink = stat->nlink; |
135 | if (tmp.st_nlink != stat->nlink) |
136 | return -EOVERFLOW; |
137 | SET_UID(tmp.st_uid, stat->uid); |
138 | SET_GID(tmp.st_gid, stat->gid); |
139 | tmp.st_rdev = old_encode_dev(stat->rdev); |
140 | #if BITS_PER_LONG == 32 |
141 | if (stat->size > MAX_NON_LFS) |
142 | return -EOVERFLOW; |
143 | #endif |
144 | tmp.st_size = stat->size; |
145 | tmp.st_atime = stat->atime.tv_sec; |
146 | tmp.st_mtime = stat->mtime.tv_sec; |
147 | tmp.st_ctime = stat->ctime.tv_sec; |
148 | return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0; |
149 | } |
150 | |
151 | asmlinkage long sys_stat(char __user * filename, struct __old_kernel_stat __user * statbuf) |
152 | { |
153 | struct kstat stat; |
154 | int error = vfs_stat(filename, &stat); |
155 | |
156 | if (!error) |
157 | error = cp_old_stat(&stat, statbuf); |
158 | |
159 | return error; |
160 | } |
161 | asmlinkage long sys_lstat(char __user * filename, struct __old_kernel_stat __user * statbuf) |
162 | { |
163 | struct kstat stat; |
164 | int error = vfs_lstat(filename, &stat); |
165 | |
166 | if (!error) |
167 | error = cp_old_stat(&stat, statbuf); |
168 | |
169 | return error; |
170 | } |
171 | asmlinkage long sys_fstat(unsigned int fd, struct __old_kernel_stat __user * statbuf) |
172 | { |
173 | struct kstat stat; |
174 | int error = vfs_fstat(fd, &stat); |
175 | |
176 | if (!error) |
177 | error = cp_old_stat(&stat, statbuf); |
178 | |
179 | return error; |
180 | } |
181 | |
182 | #endif /* __ARCH_WANT_OLD_STAT */ |
183 | |
184 | static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf) |
185 | { |
186 | struct stat tmp; |
187 | |
188 | #if BITS_PER_LONG == 32 |
189 | if (!old_valid_dev(stat->dev) || !old_valid_dev(stat->rdev)) |
190 | return -EOVERFLOW; |
191 | #else |
192 | if (!new_valid_dev(stat->dev) || !new_valid_dev(stat->rdev)) |
193 | return -EOVERFLOW; |
194 | #endif |
195 | |
196 | memset(&tmp, 0, sizeof(tmp)); |
197 | #if BITS_PER_LONG == 32 |
198 | tmp.st_dev = old_encode_dev(stat->dev); |
199 | #else |
200 | tmp.st_dev = new_encode_dev(stat->dev); |
201 | #endif |
202 | tmp.st_ino = stat->ino; |
203 | tmp.st_mode = stat->mode; |
204 | tmp.st_nlink = stat->nlink; |
205 | if (tmp.st_nlink != stat->nlink) |
206 | return -EOVERFLOW; |
207 | SET_UID(tmp.st_uid, stat->uid); |
208 | SET_GID(tmp.st_gid, stat->gid); |
209 | #if BITS_PER_LONG == 32 |
210 | tmp.st_rdev = old_encode_dev(stat->rdev); |
211 | #else |
212 | tmp.st_rdev = new_encode_dev(stat->rdev); |
213 | #endif |
214 | #if BITS_PER_LONG == 32 |
215 | if (stat->size > MAX_NON_LFS) |
216 | return -EOVERFLOW; |
217 | #endif |
218 | tmp.st_size = stat->size; |
219 | tmp.st_atime = stat->atime.tv_sec; |
220 | tmp.st_mtime = stat->mtime.tv_sec; |
221 | tmp.st_ctime = stat->ctime.tv_sec; |
222 | #ifdef STAT_HAVE_NSEC |
223 | tmp.st_atime_nsec = stat->atime.tv_nsec; |
224 | tmp.st_mtime_nsec = stat->mtime.tv_nsec; |
225 | tmp.st_ctime_nsec = stat->ctime.tv_nsec; |
226 | #endif |
227 | tmp.st_blocks = stat->blocks; |
228 | tmp.st_blksize = stat->blksize; |
229 | return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0; |
230 | } |
231 | |
232 | asmlinkage long sys_newstat(char __user * filename, struct stat __user * statbuf) |
233 | { |
234 | struct kstat stat; |
235 | int error = vfs_stat(filename, &stat); |
236 | |
237 | if (!error) |
238 | error = cp_new_stat(&stat, statbuf); |
239 | |
240 | return error; |
241 | } |
242 | asmlinkage long sys_newlstat(char __user * filename, struct stat __user * statbuf) |
243 | { |
244 | struct kstat stat; |
245 | int error = vfs_lstat(filename, &stat); |
246 | |
247 | if (!error) |
248 | error = cp_new_stat(&stat, statbuf); |
249 | |
250 | return error; |
251 | } |
252 | asmlinkage long sys_newfstat(unsigned int fd, struct stat __user * statbuf) |
253 | { |
254 | struct kstat stat; |
255 | int error = vfs_fstat(fd, &stat); |
256 | |
257 | if (!error) |
258 | error = cp_new_stat(&stat, statbuf); |
259 | |
260 | return error; |
261 | } |
262 | |
263 | asmlinkage long sys_readlink(const char __user * path, char __user * buf, int bufsiz) |
264 | { |
265 | struct nameidata nd; |
266 | int error; |
267 | |
268 | if (bufsiz <= 0) |
269 | return -EINVAL; |
270 | |
271 | error = user_path_walk_link(path, &nd); |
272 | if (!error) { |
273 | struct inode * inode = nd.dentry->d_inode; |
274 | |
275 | error = -EINVAL; |
276 | if (inode->i_op && inode->i_op->readlink) { |
277 | error = security_inode_readlink(nd.dentry); |
278 | if (!error) { |
279 | touch_atime(nd.mnt, nd.dentry); |
280 | error = inode->i_op->readlink(nd.dentry, buf, bufsiz); |
281 | } |
282 | } |
283 | path_release(&nd); |
284 | } |
285 | return error; |
286 | } |
287 | |
288 | |
289 | /* ---------- LFS-64 ----------- */ |
290 | #ifdef __ARCH_WANT_STAT64 |
291 | |
292 | static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf) |
293 | { |
294 | struct stat64 tmp; |
295 | |
296 | memset(&tmp, 0, sizeof(struct stat64)); |
297 | #ifdef CONFIG_MIPS |
298 | /* mips has weird padding, so we don't get 64 bits there */ |
299 | if (!new_valid_dev(stat->dev) || !new_valid_dev(stat->rdev)) |
300 | return -EOVERFLOW; |
301 | tmp.st_dev = new_encode_dev(stat->dev); |
302 | tmp.st_rdev = new_encode_dev(stat->rdev); |
303 | #else |
304 | tmp.st_dev = huge_encode_dev(stat->dev); |
305 | tmp.st_rdev = huge_encode_dev(stat->rdev); |
306 | #endif |
307 | tmp.st_ino = stat->ino; |
308 | #ifdef STAT64_HAS_BROKEN_ST_INO |
309 | tmp.__st_ino = stat->ino; |
310 | #endif |
311 | tmp.st_mode = stat->mode; |
312 | tmp.st_nlink = stat->nlink; |
313 | tmp.st_uid = stat->uid; |
314 | tmp.st_gid = stat->gid; |
315 | tmp.st_atime = stat->atime.tv_sec; |
316 | tmp.st_atime_nsec = stat->atime.tv_nsec; |
317 | tmp.st_mtime = stat->mtime.tv_sec; |
318 | tmp.st_mtime_nsec = stat->mtime.tv_nsec; |
319 | tmp.st_ctime = stat->ctime.tv_sec; |
320 | tmp.st_ctime_nsec = stat->ctime.tv_nsec; |
321 | tmp.st_size = stat->size; |
322 | tmp.st_blocks = stat->blocks; |
323 | tmp.st_blksize = stat->blksize; |
324 | return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0; |
325 | } |
326 | |
327 | asmlinkage long sys_stat64(char __user * filename, struct stat64 __user * statbuf) |
328 | { |
329 | struct kstat stat; |
330 | int error = vfs_stat(filename, &stat); |
331 | |
332 | if (!error) |
333 | error = cp_new_stat64(&stat, statbuf); |
334 | |
335 | return error; |
336 | } |
337 | asmlinkage long sys_lstat64(char __user * filename, struct stat64 __user * statbuf) |
338 | { |
339 | struct kstat stat; |
340 | int error = vfs_lstat(filename, &stat); |
341 | |
342 | if (!error) |
343 | error = cp_new_stat64(&stat, statbuf); |
344 | |
345 | return error; |
346 | } |
347 | asmlinkage long sys_fstat64(unsigned long fd, struct stat64 __user * statbuf) |
348 | { |
349 | struct kstat stat; |
350 | int error = vfs_fstat(fd, &stat); |
351 | |
352 | if (!error) |
353 | error = cp_new_stat64(&stat, statbuf); |
354 | |
355 | return error; |
356 | } |
357 | |
358 | #endif /* __ARCH_WANT_STAT64 */ |
359 | |
360 | void inode_add_bytes(struct inode *inode, loff_t bytes) |
361 | { |
362 | spin_lock(&inode->i_lock); |
363 | inode->i_blocks += bytes >> 9; |
364 | bytes &= 511; |
365 | inode->i_bytes += bytes; |
366 | if (inode->i_bytes >= 512) { |
367 | inode->i_blocks++; |
368 | inode->i_bytes -= 512; |
369 | } |
370 | spin_unlock(&inode->i_lock); |
371 | } |
372 | |
373 | EXPORT_SYMBOL(inode_add_bytes); |
374 | |
375 | void inode_sub_bytes(struct inode *inode, loff_t bytes) |
376 | { |
377 | spin_lock(&inode->i_lock); |
378 | inode->i_blocks -= bytes >> 9; |
379 | bytes &= 511; |
380 | if (inode->i_bytes < bytes) { |
381 | inode->i_blocks--; |
382 | inode->i_bytes += 512; |
383 | } |
384 | inode->i_bytes -= bytes; |
385 | spin_unlock(&inode->i_lock); |
386 | } |
387 | |
388 | EXPORT_SYMBOL(inode_sub_bytes); |
389 | |
390 | loff_t inode_get_bytes(struct inode *inode) |
391 | { |
392 | loff_t ret; |
393 | |
394 | spin_lock(&inode->i_lock); |
395 | ret = (((loff_t)inode->i_blocks) << 9) + inode->i_bytes; |
396 | spin_unlock(&inode->i_lock); |
397 | return ret; |
398 | } |
399 | |
400 | EXPORT_SYMBOL(inode_get_bytes); |
401 | |
402 | void inode_set_bytes(struct inode *inode, loff_t bytes) |
403 | { |
404 | /* Caller is here responsible for sufficient locking |
405 | * (ie. inode->i_lock) */ |
406 | inode->i_blocks = bytes >> 9; |
407 | inode->i_bytes = bytes & 511; |
408 | } |
409 | |
410 | EXPORT_SYMBOL(inode_set_bytes); |