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Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/fs/stat.c | |
3 | * | |
4 | * Copyright (C) 1991, 1992 Linus Torvalds | |
5 | */ | |
6 | ||
630d9c47 | 7 | #include <linux/export.h> |
1da177e4 LT |
8 | #include <linux/mm.h> |
9 | #include <linux/errno.h> | |
10 | #include <linux/file.h> | |
1da177e4 LT |
11 | #include <linux/highuid.h> |
12 | #include <linux/fs.h> | |
13 | #include <linux/namei.h> | |
14 | #include <linux/security.h> | |
15 | #include <linux/syscalls.h> | |
ba52de12 | 16 | #include <linux/pagemap.h> |
1da177e4 LT |
17 | |
18 | #include <asm/uaccess.h> | |
19 | #include <asm/unistd.h> | |
20 | ||
21 | void generic_fillattr(struct inode *inode, struct kstat *stat) | |
22 | { | |
23 | stat->dev = inode->i_sb->s_dev; | |
24 | stat->ino = inode->i_ino; | |
25 | stat->mode = inode->i_mode; | |
26 | stat->nlink = inode->i_nlink; | |
27 | stat->uid = inode->i_uid; | |
28 | stat->gid = inode->i_gid; | |
29 | stat->rdev = inode->i_rdev; | |
3ddcd056 | 30 | stat->size = i_size_read(inode); |
1da177e4 LT |
31 | stat->atime = inode->i_atime; |
32 | stat->mtime = inode->i_mtime; | |
33 | stat->ctime = inode->i_ctime; | |
ba52de12 | 34 | stat->blksize = (1 << inode->i_blkbits); |
3ddcd056 | 35 | stat->blocks = inode->i_blocks; |
1da177e4 LT |
36 | } |
37 | ||
38 | EXPORT_SYMBOL(generic_fillattr); | |
39 | ||
40 | int vfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) | |
41 | { | |
42 | struct inode *inode = dentry->d_inode; | |
43 | int retval; | |
44 | ||
45 | retval = security_inode_getattr(mnt, dentry); | |
46 | if (retval) | |
47 | return retval; | |
48 | ||
49 | if (inode->i_op->getattr) | |
50 | return inode->i_op->getattr(mnt, dentry, stat); | |
51 | ||
52 | generic_fillattr(inode, stat); | |
1da177e4 LT |
53 | return 0; |
54 | } | |
55 | ||
56 | EXPORT_SYMBOL(vfs_getattr); | |
57 | ||
1da177e4 LT |
58 | int vfs_fstat(unsigned int fd, struct kstat *stat) |
59 | { | |
2903ff01 | 60 | struct fd f = fdget_raw(fd); |
1da177e4 LT |
61 | int error = -EBADF; |
62 | ||
2903ff01 AV |
63 | if (f.file) { |
64 | error = vfs_getattr(f.file->f_path.mnt, f.file->f_path.dentry, | |
65 | stat); | |
66 | fdput(f); | |
1da177e4 LT |
67 | } |
68 | return error; | |
69 | } | |
1da177e4 LT |
70 | EXPORT_SYMBOL(vfs_fstat); |
71 | ||
c7887325 DH |
72 | int vfs_fstatat(int dfd, const char __user *filename, struct kstat *stat, |
73 | int flag) | |
0112fc22 | 74 | { |
2eae7a18 | 75 | struct path path; |
0112fc22 | 76 | int error = -EINVAL; |
2eae7a18 | 77 | int lookup_flags = 0; |
0112fc22 | 78 | |
65cfc672 AV |
79 | if ((flag & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT | |
80 | AT_EMPTY_PATH)) != 0) | |
0112fc22 OD |
81 | goto out; |
82 | ||
2eae7a18 CH |
83 | if (!(flag & AT_SYMLINK_NOFOLLOW)) |
84 | lookup_flags |= LOOKUP_FOLLOW; | |
65cfc672 AV |
85 | if (flag & AT_EMPTY_PATH) |
86 | lookup_flags |= LOOKUP_EMPTY; | |
2eae7a18 CH |
87 | |
88 | error = user_path_at(dfd, filename, lookup_flags, &path); | |
89 | if (error) | |
90 | goto out; | |
91 | ||
92 | error = vfs_getattr(path.mnt, path.dentry, stat); | |
93 | path_put(&path); | |
0112fc22 OD |
94 | out: |
95 | return error; | |
96 | } | |
0112fc22 OD |
97 | EXPORT_SYMBOL(vfs_fstatat); |
98 | ||
c7887325 | 99 | int vfs_stat(const char __user *name, struct kstat *stat) |
2eae7a18 CH |
100 | { |
101 | return vfs_fstatat(AT_FDCWD, name, stat, 0); | |
102 | } | |
103 | EXPORT_SYMBOL(vfs_stat); | |
104 | ||
c7887325 | 105 | int vfs_lstat(const char __user *name, struct kstat *stat) |
2eae7a18 CH |
106 | { |
107 | return vfs_fstatat(AT_FDCWD, name, stat, AT_SYMLINK_NOFOLLOW); | |
108 | } | |
109 | EXPORT_SYMBOL(vfs_lstat); | |
110 | ||
0112fc22 | 111 | |
1da177e4 LT |
112 | #ifdef __ARCH_WANT_OLD_STAT |
113 | ||
114 | /* | |
115 | * For backward compatibility? Maybe this should be moved | |
116 | * into arch/i386 instead? | |
117 | */ | |
118 | static int cp_old_stat(struct kstat *stat, struct __old_kernel_stat __user * statbuf) | |
119 | { | |
120 | static int warncount = 5; | |
121 | struct __old_kernel_stat tmp; | |
122 | ||
123 | if (warncount > 0) { | |
124 | warncount--; | |
125 | printk(KERN_WARNING "VFS: Warning: %s using old stat() call. Recompile your binary.\n", | |
126 | current->comm); | |
127 | } else if (warncount < 0) { | |
128 | /* it's laughable, but... */ | |
129 | warncount = 0; | |
130 | } | |
131 | ||
132 | memset(&tmp, 0, sizeof(struct __old_kernel_stat)); | |
133 | tmp.st_dev = old_encode_dev(stat->dev); | |
134 | tmp.st_ino = stat->ino; | |
afefdbb2 DH |
135 | if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino) |
136 | return -EOVERFLOW; | |
1da177e4 LT |
137 | tmp.st_mode = stat->mode; |
138 | tmp.st_nlink = stat->nlink; | |
139 | if (tmp.st_nlink != stat->nlink) | |
140 | return -EOVERFLOW; | |
a7c1938e EB |
141 | SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid)); |
142 | SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid)); | |
1da177e4 LT |
143 | tmp.st_rdev = old_encode_dev(stat->rdev); |
144 | #if BITS_PER_LONG == 32 | |
145 | if (stat->size > MAX_NON_LFS) | |
146 | return -EOVERFLOW; | |
147 | #endif | |
148 | tmp.st_size = stat->size; | |
149 | tmp.st_atime = stat->atime.tv_sec; | |
150 | tmp.st_mtime = stat->mtime.tv_sec; | |
151 | tmp.st_ctime = stat->ctime.tv_sec; | |
152 | return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0; | |
153 | } | |
154 | ||
c7887325 DH |
155 | SYSCALL_DEFINE2(stat, const char __user *, filename, |
156 | struct __old_kernel_stat __user *, statbuf) | |
1da177e4 LT |
157 | { |
158 | struct kstat stat; | |
2eae7a18 | 159 | int error; |
1da177e4 | 160 | |
2eae7a18 CH |
161 | error = vfs_stat(filename, &stat); |
162 | if (error) | |
163 | return error; | |
1da177e4 | 164 | |
2eae7a18 | 165 | return cp_old_stat(&stat, statbuf); |
1da177e4 | 166 | } |
257ac264 | 167 | |
c7887325 DH |
168 | SYSCALL_DEFINE2(lstat, const char __user *, filename, |
169 | struct __old_kernel_stat __user *, statbuf) | |
1da177e4 LT |
170 | { |
171 | struct kstat stat; | |
2eae7a18 | 172 | int error; |
1da177e4 | 173 | |
2eae7a18 CH |
174 | error = vfs_lstat(filename, &stat); |
175 | if (error) | |
176 | return error; | |
1da177e4 | 177 | |
2eae7a18 | 178 | return cp_old_stat(&stat, statbuf); |
1da177e4 | 179 | } |
257ac264 HC |
180 | |
181 | SYSCALL_DEFINE2(fstat, unsigned int, fd, struct __old_kernel_stat __user *, statbuf) | |
1da177e4 LT |
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 | ||
a52dd971 LT |
194 | #if BITS_PER_LONG == 32 |
195 | # define choose_32_64(a,b) a | |
196 | #else | |
197 | # define choose_32_64(a,b) b | |
198 | #endif | |
199 | ||
200 | #define valid_dev(x) choose_32_64(old_valid_dev,new_valid_dev)(x) | |
201 | #define encode_dev(x) choose_32_64(old_encode_dev,new_encode_dev)(x) | |
202 | ||
8529f613 LT |
203 | #ifndef INIT_STRUCT_STAT_PADDING |
204 | # define INIT_STRUCT_STAT_PADDING(st) memset(&st, 0, sizeof(st)) | |
205 | #endif | |
206 | ||
1da177e4 LT |
207 | static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf) |
208 | { | |
209 | struct stat tmp; | |
210 | ||
a52dd971 | 211 | if (!valid_dev(stat->dev) || !valid_dev(stat->rdev)) |
1da177e4 | 212 | return -EOVERFLOW; |
a52dd971 LT |
213 | #if BITS_PER_LONG == 32 |
214 | if (stat->size > MAX_NON_LFS) | |
1da177e4 LT |
215 | return -EOVERFLOW; |
216 | #endif | |
217 | ||
8529f613 | 218 | INIT_STRUCT_STAT_PADDING(tmp); |
a52dd971 | 219 | tmp.st_dev = encode_dev(stat->dev); |
1da177e4 | 220 | tmp.st_ino = stat->ino; |
afefdbb2 DH |
221 | if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino) |
222 | return -EOVERFLOW; | |
1da177e4 LT |
223 | tmp.st_mode = stat->mode; |
224 | tmp.st_nlink = stat->nlink; | |
225 | if (tmp.st_nlink != stat->nlink) | |
226 | return -EOVERFLOW; | |
a7c1938e EB |
227 | SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid)); |
228 | SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid)); | |
a52dd971 | 229 | tmp.st_rdev = encode_dev(stat->rdev); |
1da177e4 LT |
230 | tmp.st_size = stat->size; |
231 | tmp.st_atime = stat->atime.tv_sec; | |
232 | tmp.st_mtime = stat->mtime.tv_sec; | |
233 | tmp.st_ctime = stat->ctime.tv_sec; | |
234 | #ifdef STAT_HAVE_NSEC | |
235 | tmp.st_atime_nsec = stat->atime.tv_nsec; | |
236 | tmp.st_mtime_nsec = stat->mtime.tv_nsec; | |
237 | tmp.st_ctime_nsec = stat->ctime.tv_nsec; | |
238 | #endif | |
239 | tmp.st_blocks = stat->blocks; | |
240 | tmp.st_blksize = stat->blksize; | |
241 | return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0; | |
242 | } | |
243 | ||
c7887325 DH |
244 | SYSCALL_DEFINE2(newstat, const char __user *, filename, |
245 | struct stat __user *, statbuf) | |
5590ff0d UD |
246 | { |
247 | struct kstat stat; | |
2eae7a18 | 248 | int error = vfs_stat(filename, &stat); |
5590ff0d | 249 | |
2eae7a18 CH |
250 | if (error) |
251 | return error; | |
252 | return cp_new_stat(&stat, statbuf); | |
5590ff0d UD |
253 | } |
254 | ||
c7887325 DH |
255 | SYSCALL_DEFINE2(newlstat, const char __user *, filename, |
256 | struct stat __user *, statbuf) | |
1da177e4 LT |
257 | { |
258 | struct kstat stat; | |
2eae7a18 | 259 | int error; |
1da177e4 | 260 | |
2eae7a18 CH |
261 | error = vfs_lstat(filename, &stat); |
262 | if (error) | |
263 | return error; | |
1da177e4 | 264 | |
2eae7a18 | 265 | return cp_new_stat(&stat, statbuf); |
1da177e4 | 266 | } |
5590ff0d | 267 | |
2833c28a | 268 | #if !defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_SYS_NEWFSTATAT) |
c7887325 | 269 | SYSCALL_DEFINE4(newfstatat, int, dfd, const char __user *, filename, |
6559eed8 | 270 | struct stat __user *, statbuf, int, flag) |
1da177e4 LT |
271 | { |
272 | struct kstat stat; | |
0112fc22 | 273 | int error; |
1da177e4 | 274 | |
0112fc22 OD |
275 | error = vfs_fstatat(dfd, filename, &stat, flag); |
276 | if (error) | |
277 | return error; | |
278 | return cp_new_stat(&stat, statbuf); | |
1da177e4 | 279 | } |
cff2b760 | 280 | #endif |
5590ff0d | 281 | |
257ac264 | 282 | SYSCALL_DEFINE2(newfstat, unsigned int, fd, struct stat __user *, statbuf) |
1da177e4 LT |
283 | { |
284 | struct kstat stat; | |
285 | int error = vfs_fstat(fd, &stat); | |
286 | ||
287 | if (!error) | |
288 | error = cp_new_stat(&stat, statbuf); | |
289 | ||
290 | return error; | |
291 | } | |
292 | ||
6559eed8 HC |
293 | SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname, |
294 | char __user *, buf, int, bufsiz) | |
1da177e4 | 295 | { |
2d8f3038 | 296 | struct path path; |
1da177e4 | 297 | int error; |
1fa1e7f6 | 298 | int empty = 0; |
1da177e4 LT |
299 | |
300 | if (bufsiz <= 0) | |
301 | return -EINVAL; | |
302 | ||
1fa1e7f6 | 303 | error = user_path_at_empty(dfd, pathname, LOOKUP_EMPTY, &path, &empty); |
1da177e4 | 304 | if (!error) { |
2d8f3038 | 305 | struct inode *inode = path.dentry->d_inode; |
1da177e4 | 306 | |
1fa1e7f6 | 307 | error = empty ? -ENOENT : -EINVAL; |
acfa4380 | 308 | if (inode->i_op->readlink) { |
2d8f3038 | 309 | error = security_inode_readlink(path.dentry); |
1da177e4 | 310 | if (!error) { |
68ac1234 | 311 | touch_atime(&path); |
2d8f3038 | 312 | error = inode->i_op->readlink(path.dentry, |
4ac91378 | 313 | buf, bufsiz); |
1da177e4 LT |
314 | } |
315 | } | |
2d8f3038 | 316 | path_put(&path); |
1da177e4 LT |
317 | } |
318 | return error; | |
319 | } | |
320 | ||
002c8976 HC |
321 | SYSCALL_DEFINE3(readlink, const char __user *, path, char __user *, buf, |
322 | int, bufsiz) | |
5590ff0d UD |
323 | { |
324 | return sys_readlinkat(AT_FDCWD, path, buf, bufsiz); | |
325 | } | |
326 | ||
1da177e4 LT |
327 | |
328 | /* ---------- LFS-64 ----------- */ | |
0753f70f | 329 | #if defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_COMPAT_STAT64) |
1da177e4 | 330 | |
8529f613 LT |
331 | #ifndef INIT_STRUCT_STAT64_PADDING |
332 | # define INIT_STRUCT_STAT64_PADDING(st) memset(&st, 0, sizeof(st)) | |
333 | #endif | |
334 | ||
1da177e4 LT |
335 | static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf) |
336 | { | |
337 | struct stat64 tmp; | |
338 | ||
8529f613 | 339 | INIT_STRUCT_STAT64_PADDING(tmp); |
1da177e4 LT |
340 | #ifdef CONFIG_MIPS |
341 | /* mips has weird padding, so we don't get 64 bits there */ | |
342 | if (!new_valid_dev(stat->dev) || !new_valid_dev(stat->rdev)) | |
343 | return -EOVERFLOW; | |
344 | tmp.st_dev = new_encode_dev(stat->dev); | |
345 | tmp.st_rdev = new_encode_dev(stat->rdev); | |
346 | #else | |
347 | tmp.st_dev = huge_encode_dev(stat->dev); | |
348 | tmp.st_rdev = huge_encode_dev(stat->rdev); | |
349 | #endif | |
350 | tmp.st_ino = stat->ino; | |
afefdbb2 DH |
351 | if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino) |
352 | return -EOVERFLOW; | |
1da177e4 LT |
353 | #ifdef STAT64_HAS_BROKEN_ST_INO |
354 | tmp.__st_ino = stat->ino; | |
355 | #endif | |
356 | tmp.st_mode = stat->mode; | |
357 | tmp.st_nlink = stat->nlink; | |
a7c1938e EB |
358 | tmp.st_uid = from_kuid_munged(current_user_ns(), stat->uid); |
359 | tmp.st_gid = from_kgid_munged(current_user_ns(), stat->gid); | |
1da177e4 LT |
360 | tmp.st_atime = stat->atime.tv_sec; |
361 | tmp.st_atime_nsec = stat->atime.tv_nsec; | |
362 | tmp.st_mtime = stat->mtime.tv_sec; | |
363 | tmp.st_mtime_nsec = stat->mtime.tv_nsec; | |
364 | tmp.st_ctime = stat->ctime.tv_sec; | |
365 | tmp.st_ctime_nsec = stat->ctime.tv_nsec; | |
366 | tmp.st_size = stat->size; | |
367 | tmp.st_blocks = stat->blocks; | |
368 | tmp.st_blksize = stat->blksize; | |
369 | return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0; | |
370 | } | |
371 | ||
c7887325 DH |
372 | SYSCALL_DEFINE2(stat64, const char __user *, filename, |
373 | struct stat64 __user *, statbuf) | |
1da177e4 LT |
374 | { |
375 | struct kstat stat; | |
376 | int error = vfs_stat(filename, &stat); | |
377 | ||
378 | if (!error) | |
379 | error = cp_new_stat64(&stat, statbuf); | |
380 | ||
381 | return error; | |
382 | } | |
257ac264 | 383 | |
c7887325 DH |
384 | SYSCALL_DEFINE2(lstat64, const char __user *, filename, |
385 | struct stat64 __user *, statbuf) | |
1da177e4 LT |
386 | { |
387 | struct kstat stat; | |
388 | int error = vfs_lstat(filename, &stat); | |
389 | ||
390 | if (!error) | |
391 | error = cp_new_stat64(&stat, statbuf); | |
392 | ||
393 | return error; | |
394 | } | |
257ac264 HC |
395 | |
396 | SYSCALL_DEFINE2(fstat64, unsigned long, fd, struct stat64 __user *, statbuf) | |
1da177e4 LT |
397 | { |
398 | struct kstat stat; | |
399 | int error = vfs_fstat(fd, &stat); | |
400 | ||
401 | if (!error) | |
402 | error = cp_new_stat64(&stat, statbuf); | |
403 | ||
404 | return error; | |
405 | } | |
406 | ||
c7887325 | 407 | SYSCALL_DEFINE4(fstatat64, int, dfd, const char __user *, filename, |
6559eed8 | 408 | struct stat64 __user *, statbuf, int, flag) |
cff2b760 UD |
409 | { |
410 | struct kstat stat; | |
0112fc22 | 411 | int error; |
cff2b760 | 412 | |
0112fc22 OD |
413 | error = vfs_fstatat(dfd, filename, &stat, flag); |
414 | if (error) | |
415 | return error; | |
416 | return cp_new_stat64(&stat, statbuf); | |
cff2b760 | 417 | } |
0753f70f | 418 | #endif /* __ARCH_WANT_STAT64 || __ARCH_WANT_COMPAT_STAT64 */ |
1da177e4 | 419 | |
b462707e DM |
420 | /* Caller is here responsible for sufficient locking (ie. inode->i_lock) */ |
421 | void __inode_add_bytes(struct inode *inode, loff_t bytes) | |
1da177e4 | 422 | { |
1da177e4 LT |
423 | inode->i_blocks += bytes >> 9; |
424 | bytes &= 511; | |
425 | inode->i_bytes += bytes; | |
426 | if (inode->i_bytes >= 512) { | |
427 | inode->i_blocks++; | |
428 | inode->i_bytes -= 512; | |
429 | } | |
b462707e DM |
430 | } |
431 | ||
432 | void inode_add_bytes(struct inode *inode, loff_t bytes) | |
433 | { | |
434 | spin_lock(&inode->i_lock); | |
435 | __inode_add_bytes(inode, bytes); | |
1da177e4 LT |
436 | spin_unlock(&inode->i_lock); |
437 | } | |
438 | ||
439 | EXPORT_SYMBOL(inode_add_bytes); | |
440 | ||
441 | void inode_sub_bytes(struct inode *inode, loff_t bytes) | |
442 | { | |
443 | spin_lock(&inode->i_lock); | |
444 | inode->i_blocks -= bytes >> 9; | |
445 | bytes &= 511; | |
446 | if (inode->i_bytes < bytes) { | |
447 | inode->i_blocks--; | |
448 | inode->i_bytes += 512; | |
449 | } | |
450 | inode->i_bytes -= bytes; | |
451 | spin_unlock(&inode->i_lock); | |
452 | } | |
453 | ||
454 | EXPORT_SYMBOL(inode_sub_bytes); | |
455 | ||
456 | loff_t inode_get_bytes(struct inode *inode) | |
457 | { | |
458 | loff_t ret; | |
459 | ||
460 | spin_lock(&inode->i_lock); | |
461 | ret = (((loff_t)inode->i_blocks) << 9) + inode->i_bytes; | |
462 | spin_unlock(&inode->i_lock); | |
463 | return ret; | |
464 | } | |
465 | ||
466 | EXPORT_SYMBOL(inode_get_bytes); | |
467 | ||
468 | void inode_set_bytes(struct inode *inode, loff_t bytes) | |
469 | { | |
470 | /* Caller is here responsible for sufficient locking | |
471 | * (ie. inode->i_lock) */ | |
472 | inode->i_blocks = bytes >> 9; | |
473 | inode->i_bytes = bytes & 511; | |
474 | } | |
475 | ||
476 | EXPORT_SYMBOL(inode_set_bytes); |