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Commit | Line | Data |
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1da177e4 LT |
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 | ||
5590ff0d | 66 | int vfs_stat_fd(int dfd, char __user *name, struct kstat *stat) |
1da177e4 LT |
67 | { |
68 | struct nameidata nd; | |
69 | int error; | |
70 | ||
5590ff0d | 71 | error = __user_walk_fd(dfd, name, LOOKUP_FOLLOW, &nd); |
1da177e4 LT |
72 | if (!error) { |
73 | error = vfs_getattr(nd.mnt, nd.dentry, stat); | |
74 | path_release(&nd); | |
75 | } | |
76 | return error; | |
77 | } | |
78 | ||
5590ff0d UD |
79 | int vfs_stat(char __user *name, struct kstat *stat) |
80 | { | |
81 | return vfs_stat_fd(AT_FDCWD, name, stat); | |
82 | } | |
83 | ||
1da177e4 LT |
84 | EXPORT_SYMBOL(vfs_stat); |
85 | ||
5590ff0d | 86 | int vfs_lstat_fd(int dfd, char __user *name, struct kstat *stat) |
1da177e4 LT |
87 | { |
88 | struct nameidata nd; | |
89 | int error; | |
90 | ||
5590ff0d | 91 | error = __user_walk_fd(dfd, name, 0, &nd); |
1da177e4 LT |
92 | if (!error) { |
93 | error = vfs_getattr(nd.mnt, nd.dentry, stat); | |
94 | path_release(&nd); | |
95 | } | |
96 | return error; | |
97 | } | |
98 | ||
5590ff0d UD |
99 | int vfs_lstat(char __user *name, struct kstat *stat) |
100 | { | |
101 | return vfs_lstat_fd(AT_FDCWD, name, stat); | |
102 | } | |
103 | ||
1da177e4 LT |
104 | EXPORT_SYMBOL(vfs_lstat); |
105 | ||
106 | int vfs_fstat(unsigned int fd, struct kstat *stat) | |
107 | { | |
108 | struct file *f = fget(fd); | |
109 | int error = -EBADF; | |
110 | ||
111 | if (f) { | |
112 | error = vfs_getattr(f->f_vfsmnt, f->f_dentry, stat); | |
113 | fput(f); | |
114 | } | |
115 | return error; | |
116 | } | |
117 | ||
118 | EXPORT_SYMBOL(vfs_fstat); | |
119 | ||
120 | #ifdef __ARCH_WANT_OLD_STAT | |
121 | ||
122 | /* | |
123 | * For backward compatibility? Maybe this should be moved | |
124 | * into arch/i386 instead? | |
125 | */ | |
126 | static int cp_old_stat(struct kstat *stat, struct __old_kernel_stat __user * statbuf) | |
127 | { | |
128 | static int warncount = 5; | |
129 | struct __old_kernel_stat tmp; | |
130 | ||
131 | if (warncount > 0) { | |
132 | warncount--; | |
133 | printk(KERN_WARNING "VFS: Warning: %s using old stat() call. Recompile your binary.\n", | |
134 | current->comm); | |
135 | } else if (warncount < 0) { | |
136 | /* it's laughable, but... */ | |
137 | warncount = 0; | |
138 | } | |
139 | ||
140 | memset(&tmp, 0, sizeof(struct __old_kernel_stat)); | |
141 | tmp.st_dev = old_encode_dev(stat->dev); | |
142 | tmp.st_ino = stat->ino; | |
143 | tmp.st_mode = stat->mode; | |
144 | tmp.st_nlink = stat->nlink; | |
145 | if (tmp.st_nlink != stat->nlink) | |
146 | return -EOVERFLOW; | |
147 | SET_UID(tmp.st_uid, stat->uid); | |
148 | SET_GID(tmp.st_gid, stat->gid); | |
149 | tmp.st_rdev = old_encode_dev(stat->rdev); | |
150 | #if BITS_PER_LONG == 32 | |
151 | if (stat->size > MAX_NON_LFS) | |
152 | return -EOVERFLOW; | |
153 | #endif | |
154 | tmp.st_size = stat->size; | |
155 | tmp.st_atime = stat->atime.tv_sec; | |
156 | tmp.st_mtime = stat->mtime.tv_sec; | |
157 | tmp.st_ctime = stat->ctime.tv_sec; | |
158 | return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0; | |
159 | } | |
160 | ||
161 | asmlinkage long sys_stat(char __user * filename, struct __old_kernel_stat __user * statbuf) | |
162 | { | |
163 | struct kstat stat; | |
5590ff0d | 164 | int error = vfs_stat_fd(AT_FDCWD, filename, &stat); |
1da177e4 LT |
165 | |
166 | if (!error) | |
167 | error = cp_old_stat(&stat, statbuf); | |
168 | ||
169 | return error; | |
170 | } | |
171 | asmlinkage long sys_lstat(char __user * filename, struct __old_kernel_stat __user * statbuf) | |
172 | { | |
173 | struct kstat stat; | |
5590ff0d | 174 | int error = vfs_lstat_fd(AT_FDCWD, filename, &stat); |
1da177e4 LT |
175 | |
176 | if (!error) | |
177 | error = cp_old_stat(&stat, statbuf); | |
178 | ||
179 | return error; | |
180 | } | |
181 | asmlinkage long sys_fstat(unsigned int fd, struct __old_kernel_stat __user * statbuf) | |
182 | { | |
183 | struct kstat stat; | |
184 | int error = vfs_fstat(fd, &stat); | |
185 | ||
186 | if (!error) | |
187 | error = cp_old_stat(&stat, statbuf); | |
188 | ||
189 | return error; | |
190 | } | |
191 | ||
192 | #endif /* __ARCH_WANT_OLD_STAT */ | |
193 | ||
194 | static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf) | |
195 | { | |
196 | struct stat tmp; | |
197 | ||
198 | #if BITS_PER_LONG == 32 | |
199 | if (!old_valid_dev(stat->dev) || !old_valid_dev(stat->rdev)) | |
200 | return -EOVERFLOW; | |
201 | #else | |
202 | if (!new_valid_dev(stat->dev) || !new_valid_dev(stat->rdev)) | |
203 | return -EOVERFLOW; | |
204 | #endif | |
205 | ||
206 | memset(&tmp, 0, sizeof(tmp)); | |
207 | #if BITS_PER_LONG == 32 | |
208 | tmp.st_dev = old_encode_dev(stat->dev); | |
209 | #else | |
210 | tmp.st_dev = new_encode_dev(stat->dev); | |
211 | #endif | |
212 | tmp.st_ino = stat->ino; | |
213 | tmp.st_mode = stat->mode; | |
214 | tmp.st_nlink = stat->nlink; | |
215 | if (tmp.st_nlink != stat->nlink) | |
216 | return -EOVERFLOW; | |
217 | SET_UID(tmp.st_uid, stat->uid); | |
218 | SET_GID(tmp.st_gid, stat->gid); | |
219 | #if BITS_PER_LONG == 32 | |
220 | tmp.st_rdev = old_encode_dev(stat->rdev); | |
221 | #else | |
222 | tmp.st_rdev = new_encode_dev(stat->rdev); | |
223 | #endif | |
224 | #if BITS_PER_LONG == 32 | |
225 | if (stat->size > MAX_NON_LFS) | |
226 | return -EOVERFLOW; | |
227 | #endif | |
228 | tmp.st_size = stat->size; | |
229 | tmp.st_atime = stat->atime.tv_sec; | |
230 | tmp.st_mtime = stat->mtime.tv_sec; | |
231 | tmp.st_ctime = stat->ctime.tv_sec; | |
232 | #ifdef STAT_HAVE_NSEC | |
233 | tmp.st_atime_nsec = stat->atime.tv_nsec; | |
234 | tmp.st_mtime_nsec = stat->mtime.tv_nsec; | |
235 | tmp.st_ctime_nsec = stat->ctime.tv_nsec; | |
236 | #endif | |
237 | tmp.st_blocks = stat->blocks; | |
238 | tmp.st_blksize = stat->blksize; | |
239 | return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0; | |
240 | } | |
241 | ||
5590ff0d UD |
242 | asmlinkage long sys_newstat(char __user *filename, struct stat __user *statbuf) |
243 | { | |
244 | struct kstat stat; | |
245 | int error = vfs_stat_fd(AT_FDCWD, filename, &stat); | |
246 | ||
247 | if (!error) | |
248 | error = cp_new_stat(&stat, statbuf); | |
249 | ||
250 | return error; | |
251 | } | |
252 | ||
253 | asmlinkage long sys_newlstat(char __user *filename, struct stat __user *statbuf) | |
1da177e4 LT |
254 | { |
255 | struct kstat stat; | |
5590ff0d | 256 | int error = vfs_lstat_fd(AT_FDCWD, filename, &stat); |
1da177e4 LT |
257 | |
258 | if (!error) | |
259 | error = cp_new_stat(&stat, statbuf); | |
260 | ||
261 | return error; | |
262 | } | |
5590ff0d | 263 | |
2833c28a | 264 | #if !defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_SYS_NEWFSTATAT) |
5590ff0d UD |
265 | asmlinkage long sys_newfstatat(int dfd, char __user *filename, |
266 | struct stat __user *statbuf, int flag) | |
1da177e4 LT |
267 | { |
268 | struct kstat stat; | |
5590ff0d UD |
269 | int error = -EINVAL; |
270 | ||
271 | if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0) | |
272 | goto out; | |
273 | ||
274 | if (flag & AT_SYMLINK_NOFOLLOW) | |
275 | error = vfs_lstat_fd(dfd, filename, &stat); | |
276 | else | |
277 | error = vfs_stat_fd(dfd, filename, &stat); | |
1da177e4 LT |
278 | |
279 | if (!error) | |
280 | error = cp_new_stat(&stat, statbuf); | |
281 | ||
5590ff0d | 282 | out: |
1da177e4 LT |
283 | return error; |
284 | } | |
cff2b760 | 285 | #endif |
5590ff0d UD |
286 | |
287 | asmlinkage long sys_newfstat(unsigned int fd, struct stat __user *statbuf) | |
1da177e4 LT |
288 | { |
289 | struct kstat stat; | |
290 | int error = vfs_fstat(fd, &stat); | |
291 | ||
292 | if (!error) | |
293 | error = cp_new_stat(&stat, statbuf); | |
294 | ||
295 | return error; | |
296 | } | |
297 | ||
5590ff0d UD |
298 | asmlinkage long sys_readlinkat(int dfd, const char __user *path, |
299 | char __user *buf, int bufsiz) | |
1da177e4 LT |
300 | { |
301 | struct nameidata nd; | |
302 | int error; | |
303 | ||
304 | if (bufsiz <= 0) | |
305 | return -EINVAL; | |
306 | ||
5590ff0d | 307 | error = __user_walk_fd(dfd, path, 0, &nd); |
1da177e4 LT |
308 | if (!error) { |
309 | struct inode * inode = nd.dentry->d_inode; | |
310 | ||
311 | error = -EINVAL; | |
312 | if (inode->i_op && inode->i_op->readlink) { | |
313 | error = security_inode_readlink(nd.dentry); | |
314 | if (!error) { | |
315 | touch_atime(nd.mnt, nd.dentry); | |
316 | error = inode->i_op->readlink(nd.dentry, buf, bufsiz); | |
317 | } | |
318 | } | |
319 | path_release(&nd); | |
320 | } | |
321 | return error; | |
322 | } | |
323 | ||
5590ff0d UD |
324 | asmlinkage long sys_readlink(const char __user *path, char __user *buf, |
325 | int bufsiz) | |
326 | { | |
327 | return sys_readlinkat(AT_FDCWD, path, buf, bufsiz); | |
328 | } | |
329 | ||
1da177e4 LT |
330 | |
331 | /* ---------- LFS-64 ----------- */ | |
332 | #ifdef __ARCH_WANT_STAT64 | |
333 | ||
334 | static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf) | |
335 | { | |
336 | struct stat64 tmp; | |
337 | ||
338 | memset(&tmp, 0, sizeof(struct stat64)); | |
339 | #ifdef CONFIG_MIPS | |
340 | /* mips has weird padding, so we don't get 64 bits there */ | |
341 | if (!new_valid_dev(stat->dev) || !new_valid_dev(stat->rdev)) | |
342 | return -EOVERFLOW; | |
343 | tmp.st_dev = new_encode_dev(stat->dev); | |
344 | tmp.st_rdev = new_encode_dev(stat->rdev); | |
345 | #else | |
346 | tmp.st_dev = huge_encode_dev(stat->dev); | |
347 | tmp.st_rdev = huge_encode_dev(stat->rdev); | |
348 | #endif | |
349 | tmp.st_ino = stat->ino; | |
350 | #ifdef STAT64_HAS_BROKEN_ST_INO | |
351 | tmp.__st_ino = stat->ino; | |
352 | #endif | |
353 | tmp.st_mode = stat->mode; | |
354 | tmp.st_nlink = stat->nlink; | |
355 | tmp.st_uid = stat->uid; | |
356 | tmp.st_gid = stat->gid; | |
357 | tmp.st_atime = stat->atime.tv_sec; | |
358 | tmp.st_atime_nsec = stat->atime.tv_nsec; | |
359 | tmp.st_mtime = stat->mtime.tv_sec; | |
360 | tmp.st_mtime_nsec = stat->mtime.tv_nsec; | |
361 | tmp.st_ctime = stat->ctime.tv_sec; | |
362 | tmp.st_ctime_nsec = stat->ctime.tv_nsec; | |
363 | tmp.st_size = stat->size; | |
364 | tmp.st_blocks = stat->blocks; | |
365 | tmp.st_blksize = stat->blksize; | |
366 | return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0; | |
367 | } | |
368 | ||
369 | asmlinkage long sys_stat64(char __user * filename, struct stat64 __user * statbuf) | |
370 | { | |
371 | struct kstat stat; | |
372 | int error = vfs_stat(filename, &stat); | |
373 | ||
374 | if (!error) | |
375 | error = cp_new_stat64(&stat, statbuf); | |
376 | ||
377 | return error; | |
378 | } | |
379 | asmlinkage long sys_lstat64(char __user * filename, struct stat64 __user * statbuf) | |
380 | { | |
381 | struct kstat stat; | |
382 | int error = vfs_lstat(filename, &stat); | |
383 | ||
384 | if (!error) | |
385 | error = cp_new_stat64(&stat, statbuf); | |
386 | ||
387 | return error; | |
388 | } | |
389 | asmlinkage long sys_fstat64(unsigned long fd, struct stat64 __user * statbuf) | |
390 | { | |
391 | struct kstat stat; | |
392 | int error = vfs_fstat(fd, &stat); | |
393 | ||
394 | if (!error) | |
395 | error = cp_new_stat64(&stat, statbuf); | |
396 | ||
397 | return error; | |
398 | } | |
399 | ||
cff2b760 UD |
400 | asmlinkage long sys_fstatat64(int dfd, char __user *filename, |
401 | struct stat64 __user *statbuf, int flag) | |
402 | { | |
403 | struct kstat stat; | |
404 | int error = -EINVAL; | |
405 | ||
406 | if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0) | |
407 | goto out; | |
408 | ||
409 | if (flag & AT_SYMLINK_NOFOLLOW) | |
410 | error = vfs_lstat_fd(dfd, filename, &stat); | |
411 | else | |
412 | error = vfs_stat_fd(dfd, filename, &stat); | |
413 | ||
414 | if (!error) | |
415 | error = cp_new_stat64(&stat, statbuf); | |
416 | ||
417 | out: | |
418 | return error; | |
419 | } | |
1da177e4 LT |
420 | #endif /* __ARCH_WANT_STAT64 */ |
421 | ||
422 | void inode_add_bytes(struct inode *inode, loff_t bytes) | |
423 | { | |
424 | spin_lock(&inode->i_lock); | |
425 | inode->i_blocks += bytes >> 9; | |
426 | bytes &= 511; | |
427 | inode->i_bytes += bytes; | |
428 | if (inode->i_bytes >= 512) { | |
429 | inode->i_blocks++; | |
430 | inode->i_bytes -= 512; | |
431 | } | |
432 | spin_unlock(&inode->i_lock); | |
433 | } | |
434 | ||
435 | EXPORT_SYMBOL(inode_add_bytes); | |
436 | ||
437 | void inode_sub_bytes(struct inode *inode, loff_t bytes) | |
438 | { | |
439 | spin_lock(&inode->i_lock); | |
440 | inode->i_blocks -= bytes >> 9; | |
441 | bytes &= 511; | |
442 | if (inode->i_bytes < bytes) { | |
443 | inode->i_blocks--; | |
444 | inode->i_bytes += 512; | |
445 | } | |
446 | inode->i_bytes -= bytes; | |
447 | spin_unlock(&inode->i_lock); | |
448 | } | |
449 | ||
450 | EXPORT_SYMBOL(inode_sub_bytes); | |
451 | ||
452 | loff_t inode_get_bytes(struct inode *inode) | |
453 | { | |
454 | loff_t ret; | |
455 | ||
456 | spin_lock(&inode->i_lock); | |
457 | ret = (((loff_t)inode->i_blocks) << 9) + inode->i_bytes; | |
458 | spin_unlock(&inode->i_lock); | |
459 | return ret; | |
460 | } | |
461 | ||
462 | EXPORT_SYMBOL(inode_get_bytes); | |
463 | ||
464 | void inode_set_bytes(struct inode *inode, loff_t bytes) | |
465 | { | |
466 | /* Caller is here responsible for sufficient locking | |
467 | * (ie. inode->i_lock) */ | |
468 | inode->i_blocks = bytes >> 9; | |
469 | inode->i_bytes = bytes & 511; | |
470 | } | |
471 | ||
472 | EXPORT_SYMBOL(inode_set_bytes); |