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1 | /* |
2 | * linux/fs/stat.c |
3 | * |
4 | * Copyright (C) 1991, 1992 Linus Torvalds |
5 | */ |
6 | |
7 | #include <linux/module.h> |
8 | #include <linux/mm.h> |
9 | #include <linux/errno.h> |
10 | #include <linux/file.h> |
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> |
16 | #include <linux/pagemap.h> |
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; |
30 | stat->atime = inode->i_atime; |
31 | stat->mtime = inode->i_mtime; |
32 | stat->ctime = inode->i_ctime; |
33 | stat->size = i_size_read(inode); |
34 | stat->blocks = inode->i_blocks; |
35 | stat->blksize = (1 << inode->i_blkbits); |
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); |
53 | return 0; |
54 | } |
55 | |
56 | EXPORT_SYMBOL(vfs_getattr); |
57 | |
58 | int vfs_fstat(unsigned int fd, struct kstat *stat) |
59 | { |
60 | struct file *f = fget(fd); |
61 | int error = -EBADF; |
62 | |
63 | if (f) { |
64 | error = vfs_getattr(f->f_path.mnt, f->f_path.dentry, stat); |
65 | fput(f); |
66 | } |
67 | return error; |
68 | } |
69 | EXPORT_SYMBOL(vfs_fstat); |
70 | |
71 | int vfs_fstatat(int dfd, const char __user *filename, struct kstat *stat, |
72 | int flag) |
73 | { |
74 | struct path path; |
75 | int error = -EINVAL; |
76 | int lookup_flags = 0; |
77 | |
78 | if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0) |
79 | goto out; |
80 | |
81 | if (!(flag & AT_SYMLINK_NOFOLLOW)) |
82 | lookup_flags |= LOOKUP_FOLLOW; |
83 | |
84 | error = user_path_at(dfd, filename, lookup_flags, &path); |
85 | if (error) |
86 | goto out; |
87 | |
88 | error = vfs_getattr(path.mnt, path.dentry, stat); |
89 | path_put(&path); |
90 | out: |
91 | return error; |
92 | } |
93 | EXPORT_SYMBOL(vfs_fstatat); |
94 | |
95 | int vfs_stat(const char __user *name, struct kstat *stat) |
96 | { |
97 | return vfs_fstatat(AT_FDCWD, name, stat, 0); |
98 | } |
99 | EXPORT_SYMBOL(vfs_stat); |
100 | |
101 | int vfs_lstat(const char __user *name, struct kstat *stat) |
102 | { |
103 | return vfs_fstatat(AT_FDCWD, name, stat, AT_SYMLINK_NOFOLLOW); |
104 | } |
105 | EXPORT_SYMBOL(vfs_lstat); |
106 | |
107 | |
108 | #ifdef __ARCH_WANT_OLD_STAT |
109 | |
110 | /* |
111 | * For backward compatibility? Maybe this should be moved |
112 | * into arch/i386 instead? |
113 | */ |
114 | static int cp_old_stat(struct kstat *stat, struct __old_kernel_stat __user * statbuf) |
115 | { |
116 | static int warncount = 5; |
117 | struct __old_kernel_stat tmp; |
118 | |
119 | if (warncount > 0) { |
120 | warncount--; |
121 | printk(KERN_WARNING "VFS: Warning: %s using old stat() call. Recompile your binary.\n", |
122 | current->comm); |
123 | } else if (warncount < 0) { |
124 | /* it's laughable, but... */ |
125 | warncount = 0; |
126 | } |
127 | |
128 | memset(&tmp, 0, sizeof(struct __old_kernel_stat)); |
129 | tmp.st_dev = old_encode_dev(stat->dev); |
130 | tmp.st_ino = stat->ino; |
131 | if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino) |
132 | return -EOVERFLOW; |
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 | SYSCALL_DEFINE2(stat, const char __user *, filename, |
152 | struct __old_kernel_stat __user *, statbuf) |
153 | { |
154 | struct kstat stat; |
155 | int error; |
156 | |
157 | error = vfs_stat(filename, &stat); |
158 | if (error) |
159 | return error; |
160 | |
161 | return cp_old_stat(&stat, statbuf); |
162 | } |
163 | |
164 | SYSCALL_DEFINE2(lstat, const char __user *, filename, |
165 | struct __old_kernel_stat __user *, statbuf) |
166 | { |
167 | struct kstat stat; |
168 | int error; |
169 | |
170 | error = vfs_lstat(filename, &stat); |
171 | if (error) |
172 | return error; |
173 | |
174 | return cp_old_stat(&stat, statbuf); |
175 | } |
176 | |
177 | SYSCALL_DEFINE2(fstat, unsigned int, fd, struct __old_kernel_stat __user *, statbuf) |
178 | { |
179 | struct kstat stat; |
180 | int error = vfs_fstat(fd, &stat); |
181 | |
182 | if (!error) |
183 | error = cp_old_stat(&stat, statbuf); |
184 | |
185 | return error; |
186 | } |
187 | |
188 | #endif /* __ARCH_WANT_OLD_STAT */ |
189 | |
190 | static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf) |
191 | { |
192 | struct stat tmp; |
193 | |
194 | #if BITS_PER_LONG == 32 |
195 | if (!old_valid_dev(stat->dev) || !old_valid_dev(stat->rdev)) |
196 | return -EOVERFLOW; |
197 | #else |
198 | if (!new_valid_dev(stat->dev) || !new_valid_dev(stat->rdev)) |
199 | return -EOVERFLOW; |
200 | #endif |
201 | |
202 | memset(&tmp, 0, sizeof(tmp)); |
203 | #if BITS_PER_LONG == 32 |
204 | tmp.st_dev = old_encode_dev(stat->dev); |
205 | #else |
206 | tmp.st_dev = new_encode_dev(stat->dev); |
207 | #endif |
208 | tmp.st_ino = stat->ino; |
209 | if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino) |
210 | return -EOVERFLOW; |
211 | tmp.st_mode = stat->mode; |
212 | tmp.st_nlink = stat->nlink; |
213 | if (tmp.st_nlink != stat->nlink) |
214 | return -EOVERFLOW; |
215 | SET_UID(tmp.st_uid, stat->uid); |
216 | SET_GID(tmp.st_gid, stat->gid); |
217 | #if BITS_PER_LONG == 32 |
218 | tmp.st_rdev = old_encode_dev(stat->rdev); |
219 | #else |
220 | tmp.st_rdev = new_encode_dev(stat->rdev); |
221 | #endif |
222 | #if BITS_PER_LONG == 32 |
223 | if (stat->size > MAX_NON_LFS) |
224 | return -EOVERFLOW; |
225 | #endif |
226 | tmp.st_size = stat->size; |
227 | tmp.st_atime = stat->atime.tv_sec; |
228 | tmp.st_mtime = stat->mtime.tv_sec; |
229 | tmp.st_ctime = stat->ctime.tv_sec; |
230 | #ifdef STAT_HAVE_NSEC |
231 | tmp.st_atime_nsec = stat->atime.tv_nsec; |
232 | tmp.st_mtime_nsec = stat->mtime.tv_nsec; |
233 | tmp.st_ctime_nsec = stat->ctime.tv_nsec; |
234 | #endif |
235 | tmp.st_blocks = stat->blocks; |
236 | tmp.st_blksize = stat->blksize; |
237 | return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0; |
238 | } |
239 | |
240 | SYSCALL_DEFINE2(newstat, const char __user *, filename, |
241 | struct stat __user *, statbuf) |
242 | { |
243 | struct kstat stat; |
244 | int error = vfs_stat(filename, &stat); |
245 | |
246 | if (error) |
247 | return error; |
248 | return cp_new_stat(&stat, statbuf); |
249 | } |
250 | |
251 | SYSCALL_DEFINE2(newlstat, const char __user *, filename, |
252 | struct stat __user *, statbuf) |
253 | { |
254 | struct kstat stat; |
255 | int error; |
256 | |
257 | error = vfs_lstat(filename, &stat); |
258 | if (error) |
259 | return error; |
260 | |
261 | return cp_new_stat(&stat, statbuf); |
262 | } |
263 | |
264 | #if !defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_SYS_NEWFSTATAT) |
265 | SYSCALL_DEFINE4(newfstatat, int, dfd, const char __user *, filename, |
266 | struct stat __user *, statbuf, int, flag) |
267 | { |
268 | struct kstat stat; |
269 | int error; |
270 | |
271 | error = vfs_fstatat(dfd, filename, &stat, flag); |
272 | if (error) |
273 | return error; |
274 | return cp_new_stat(&stat, statbuf); |
275 | } |
276 | #endif |
277 | |
278 | SYSCALL_DEFINE2(newfstat, unsigned int, fd, struct stat __user *, statbuf) |
279 | { |
280 | struct kstat stat; |
281 | int error = vfs_fstat(fd, &stat); |
282 | |
283 | if (!error) |
284 | error = cp_new_stat(&stat, statbuf); |
285 | |
286 | return error; |
287 | } |
288 | |
289 | SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname, |
290 | char __user *, buf, int, bufsiz) |
291 | { |
292 | struct path path; |
293 | int error; |
294 | |
295 | if (bufsiz <= 0) |
296 | return -EINVAL; |
297 | |
298 | error = user_path_at(dfd, pathname, 0, &path); |
299 | if (!error) { |
300 | struct inode *inode = path.dentry->d_inode; |
301 | |
302 | error = -EINVAL; |
303 | if (inode->i_op->readlink) { |
304 | error = security_inode_readlink(path.dentry); |
305 | if (!error) { |
306 | touch_atime(path.mnt, path.dentry); |
307 | error = inode->i_op->readlink(path.dentry, |
308 | buf, bufsiz); |
309 | } |
310 | } |
311 | path_put(&path); |
312 | } |
313 | return error; |
314 | } |
315 | |
316 | SYSCALL_DEFINE3(readlink, const char __user *, path, char __user *, buf, |
317 | int, bufsiz) |
318 | { |
319 | return sys_readlinkat(AT_FDCWD, path, buf, bufsiz); |
320 | } |
321 | |
322 | |
323 | /* ---------- LFS-64 ----------- */ |
324 | #ifdef __ARCH_WANT_STAT64 |
325 | |
326 | static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf) |
327 | { |
328 | struct stat64 tmp; |
329 | |
330 | memset(&tmp, 0, sizeof(struct stat64)); |
331 | #ifdef CONFIG_MIPS |
332 | /* mips has weird padding, so we don't get 64 bits there */ |
333 | if (!new_valid_dev(stat->dev) || !new_valid_dev(stat->rdev)) |
334 | return -EOVERFLOW; |
335 | tmp.st_dev = new_encode_dev(stat->dev); |
336 | tmp.st_rdev = new_encode_dev(stat->rdev); |
337 | #else |
338 | tmp.st_dev = huge_encode_dev(stat->dev); |
339 | tmp.st_rdev = huge_encode_dev(stat->rdev); |
340 | #endif |
341 | tmp.st_ino = stat->ino; |
342 | if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino) |
343 | return -EOVERFLOW; |
344 | #ifdef STAT64_HAS_BROKEN_ST_INO |
345 | tmp.__st_ino = stat->ino; |
346 | #endif |
347 | tmp.st_mode = stat->mode; |
348 | tmp.st_nlink = stat->nlink; |
349 | tmp.st_uid = stat->uid; |
350 | tmp.st_gid = stat->gid; |
351 | tmp.st_atime = stat->atime.tv_sec; |
352 | tmp.st_atime_nsec = stat->atime.tv_nsec; |
353 | tmp.st_mtime = stat->mtime.tv_sec; |
354 | tmp.st_mtime_nsec = stat->mtime.tv_nsec; |
355 | tmp.st_ctime = stat->ctime.tv_sec; |
356 | tmp.st_ctime_nsec = stat->ctime.tv_nsec; |
357 | tmp.st_size = stat->size; |
358 | tmp.st_blocks = stat->blocks; |
359 | tmp.st_blksize = stat->blksize; |
360 | return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0; |
361 | } |
362 | |
363 | SYSCALL_DEFINE2(stat64, const char __user *, filename, |
364 | struct stat64 __user *, statbuf) |
365 | { |
366 | struct kstat stat; |
367 | int error = vfs_stat(filename, &stat); |
368 | |
369 | if (!error) |
370 | error = cp_new_stat64(&stat, statbuf); |
371 | |
372 | return error; |
373 | } |
374 | |
375 | SYSCALL_DEFINE2(lstat64, const char __user *, filename, |
376 | struct stat64 __user *, statbuf) |
377 | { |
378 | struct kstat stat; |
379 | int error = vfs_lstat(filename, &stat); |
380 | |
381 | if (!error) |
382 | error = cp_new_stat64(&stat, statbuf); |
383 | |
384 | return error; |
385 | } |
386 | |
387 | SYSCALL_DEFINE2(fstat64, unsigned long, fd, struct stat64 __user *, statbuf) |
388 | { |
389 | struct kstat stat; |
390 | int error = vfs_fstat(fd, &stat); |
391 | |
392 | if (!error) |
393 | error = cp_new_stat64(&stat, statbuf); |
394 | |
395 | return error; |
396 | } |
397 | |
398 | SYSCALL_DEFINE4(fstatat64, int, dfd, const char __user *, filename, |
399 | struct stat64 __user *, statbuf, int, flag) |
400 | { |
401 | struct kstat stat; |
402 | int error; |
403 | |
404 | error = vfs_fstatat(dfd, filename, &stat, flag); |
405 | if (error) |
406 | return error; |
407 | return cp_new_stat64(&stat, statbuf); |
408 | } |
409 | #endif /* __ARCH_WANT_STAT64 */ |
410 | |
411 | /* Caller is here responsible for sufficient locking (ie. inode->i_lock) */ |
412 | void __inode_add_bytes(struct inode *inode, loff_t bytes) |
413 | { |
414 | inode->i_blocks += bytes >> 9; |
415 | bytes &= 511; |
416 | inode->i_bytes += bytes; |
417 | if (inode->i_bytes >= 512) { |
418 | inode->i_blocks++; |
419 | inode->i_bytes -= 512; |
420 | } |
421 | } |
422 | |
423 | void inode_add_bytes(struct inode *inode, loff_t bytes) |
424 | { |
425 | spin_lock(&inode->i_lock); |
426 | __inode_add_bytes(inode, bytes); |
427 | spin_unlock(&inode->i_lock); |
428 | } |
429 | |
430 | EXPORT_SYMBOL(inode_add_bytes); |
431 | |
432 | void inode_sub_bytes(struct inode *inode, loff_t bytes) |
433 | { |
434 | spin_lock(&inode->i_lock); |
435 | inode->i_blocks -= bytes >> 9; |
436 | bytes &= 511; |
437 | if (inode->i_bytes < bytes) { |
438 | inode->i_blocks--; |
439 | inode->i_bytes += 512; |
440 | } |
441 | inode->i_bytes -= bytes; |
442 | spin_unlock(&inode->i_lock); |
443 | } |
444 | |
445 | EXPORT_SYMBOL(inode_sub_bytes); |
446 | |
447 | loff_t inode_get_bytes(struct inode *inode) |
448 | { |
449 | loff_t ret; |
450 | |
451 | spin_lock(&inode->i_lock); |
452 | ret = (((loff_t)inode->i_blocks) << 9) + inode->i_bytes; |
453 | spin_unlock(&inode->i_lock); |
454 | return ret; |
455 | } |
456 | |
457 | EXPORT_SYMBOL(inode_get_bytes); |
458 | |
459 | void inode_set_bytes(struct inode *inode, loff_t bytes) |
460 | { |
461 | /* Caller is here responsible for sufficient locking |
462 | * (ie. inode->i_lock) */ |
463 | inode->i_blocks = bytes >> 9; |
464 | inode->i_bytes = bytes & 511; |
465 | } |
466 | |
467 | EXPORT_SYMBOL(inode_set_bytes); |
468 |
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