Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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kernel
os
linux
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
21void 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
38EXPORT_SYMBOL(generic_fillattr);
39
40int 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
56EXPORT_SYMBOL(vfs_getattr);
57
58int 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}
69EXPORT_SYMBOL(vfs_fstat);
70
71int 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 | AT_NO_AUTOMOUNT)) != 0)
79 goto out;
80
81 if (!(flag & AT_SYMLINK_NOFOLLOW))
82 lookup_flags |= LOOKUP_FOLLOW;
83 if (flag & AT_NO_AUTOMOUNT)
84 lookup_flags |= LOOKUP_NO_AUTOMOUNT;
85
86 error = user_path_at(dfd, filename, lookup_flags, &path);
87 if (error)
88 goto out;
89
90 error = vfs_getattr(path.mnt, path.dentry, stat);
91 path_put(&path);
92out:
93 return error;
94}
95EXPORT_SYMBOL(vfs_fstatat);
96
97int vfs_stat(const char __user *name, struct kstat *stat)
98{
99 return vfs_fstatat(AT_FDCWD, name, stat, 0);
100}
101EXPORT_SYMBOL(vfs_stat);
102
103int vfs_lstat(const char __user *name, struct kstat *stat)
104{
105 return vfs_fstatat(AT_FDCWD, name, stat, AT_SYMLINK_NOFOLLOW);
106}
107EXPORT_SYMBOL(vfs_lstat);
108
109
110#ifdef __ARCH_WANT_OLD_STAT
111
112/*
113 * For backward compatibility? Maybe this should be moved
114 * into arch/i386 instead?
115 */
116static 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 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
134 return -EOVERFLOW;
135 tmp.st_mode = stat->mode;
136 tmp.st_nlink = stat->nlink;
137 if (tmp.st_nlink != stat->nlink)
138 return -EOVERFLOW;
139 SET_UID(tmp.st_uid, stat->uid);
140 SET_GID(tmp.st_gid, stat->gid);
141 tmp.st_rdev = old_encode_dev(stat->rdev);
142#if BITS_PER_LONG == 32
143 if (stat->size > MAX_NON_LFS)
144 return -EOVERFLOW;
145#endif
146 tmp.st_size = stat->size;
147 tmp.st_atime = stat->atime.tv_sec;
148 tmp.st_mtime = stat->mtime.tv_sec;
149 tmp.st_ctime = stat->ctime.tv_sec;
150 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
151}
152
153SYSCALL_DEFINE2(stat, const char __user *, filename,
154 struct __old_kernel_stat __user *, statbuf)
155{
156 struct kstat stat;
157 int error;
158
159 error = vfs_stat(filename, &stat);
160 if (error)
161 return error;
162
163 return cp_old_stat(&stat, statbuf);
164}
165
166SYSCALL_DEFINE2(lstat, const char __user *, filename,
167 struct __old_kernel_stat __user *, statbuf)
168{
169 struct kstat stat;
170 int error;
171
172 error = vfs_lstat(filename, &stat);
173 if (error)
174 return error;
175
176 return cp_old_stat(&stat, statbuf);
177}
178
179SYSCALL_DEFINE2(fstat, unsigned int, fd, struct __old_kernel_stat __user *, statbuf)
180{
181 struct kstat stat;
182 int error = vfs_fstat(fd, &stat);
183
184 if (!error)
185 error = cp_old_stat(&stat, statbuf);
186
187 return error;
188}
189
190#endif /* __ARCH_WANT_OLD_STAT */
191
192static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf)
193{
194 struct stat tmp;
195
196#if BITS_PER_LONG == 32
197 if (!old_valid_dev(stat->dev) || !old_valid_dev(stat->rdev))
198 return -EOVERFLOW;
199#else
200 if (!new_valid_dev(stat->dev) || !new_valid_dev(stat->rdev))
201 return -EOVERFLOW;
202#endif
203
204 memset(&tmp, 0, sizeof(tmp));
205#if BITS_PER_LONG == 32
206 tmp.st_dev = old_encode_dev(stat->dev);
207#else
208 tmp.st_dev = new_encode_dev(stat->dev);
209#endif
210 tmp.st_ino = stat->ino;
211 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
212 return -EOVERFLOW;
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
242SYSCALL_DEFINE2(newstat, const char __user *, filename,
243 struct stat __user *, statbuf)
244{
245 struct kstat stat;
246 int error = vfs_stat(filename, &stat);
247
248 if (error)
249 return error;
250 return cp_new_stat(&stat, statbuf);
251}
252
253SYSCALL_DEFINE2(newlstat, const char __user *, filename,
254 struct stat __user *, statbuf)
255{
256 struct kstat stat;
257 int error;
258
259 error = vfs_lstat(filename, &stat);
260 if (error)
261 return error;
262
263 return cp_new_stat(&stat, statbuf);
264}
265
266#if !defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_SYS_NEWFSTATAT)
267SYSCALL_DEFINE4(newfstatat, int, dfd, const char __user *, filename,
268 struct stat __user *, statbuf, int, flag)
269{
270 struct kstat stat;
271 int error;
272
273 error = vfs_fstatat(dfd, filename, &stat, flag);
274 if (error)
275 return error;
276 return cp_new_stat(&stat, statbuf);
277}
278#endif
279
280SYSCALL_DEFINE2(newfstat, unsigned int, fd, struct stat __user *, statbuf)
281{
282 struct kstat stat;
283 int error = vfs_fstat(fd, &stat);
284
285 if (!error)
286 error = cp_new_stat(&stat, statbuf);
287
288 return error;
289}
290
291SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname,
292 char __user *, buf, int, bufsiz)
293{
294 struct path path;
295 int error;
296
297 if (bufsiz <= 0)
298 return -EINVAL;
299
300 error = user_path_at(dfd, pathname, 0, &path);
301 if (!error) {
302 struct inode *inode = path.dentry->d_inode;
303
304 error = -EINVAL;
305 if (inode->i_op->readlink) {
306 error = security_inode_readlink(path.dentry);
307 if (!error) {
308 touch_atime(path.mnt, path.dentry);
309 error = inode->i_op->readlink(path.dentry,
310 buf, bufsiz);
311 }
312 }
313 path_put(&path);
314 }
315 return error;
316}
317
318SYSCALL_DEFINE3(readlink, const char __user *, path, char __user *, buf,
319 int, bufsiz)
320{
321 return sys_readlinkat(AT_FDCWD, path, buf, bufsiz);
322}
323
324
325/* ---------- LFS-64 ----------- */
326#ifdef __ARCH_WANT_STAT64
327
328static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf)
329{
330 struct stat64 tmp;
331
332 memset(&tmp, 0, sizeof(struct stat64));
333#ifdef CONFIG_MIPS
334 /* mips has weird padding, so we don't get 64 bits there */
335 if (!new_valid_dev(stat->dev) || !new_valid_dev(stat->rdev))
336 return -EOVERFLOW;
337 tmp.st_dev = new_encode_dev(stat->dev);
338 tmp.st_rdev = new_encode_dev(stat->rdev);
339#else
340 tmp.st_dev = huge_encode_dev(stat->dev);
341 tmp.st_rdev = huge_encode_dev(stat->rdev);
342#endif
343 tmp.st_ino = stat->ino;
344 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
345 return -EOVERFLOW;
346#ifdef STAT64_HAS_BROKEN_ST_INO
347 tmp.__st_ino = stat->ino;
348#endif
349 tmp.st_mode = stat->mode;
350 tmp.st_nlink = stat->nlink;
351 tmp.st_uid = stat->uid;
352 tmp.st_gid = stat->gid;
353 tmp.st_atime = stat->atime.tv_sec;
354 tmp.st_atime_nsec = stat->atime.tv_nsec;
355 tmp.st_mtime = stat->mtime.tv_sec;
356 tmp.st_mtime_nsec = stat->mtime.tv_nsec;
357 tmp.st_ctime = stat->ctime.tv_sec;
358 tmp.st_ctime_nsec = stat->ctime.tv_nsec;
359 tmp.st_size = stat->size;
360 tmp.st_blocks = stat->blocks;
361 tmp.st_blksize = stat->blksize;
362 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
363}
364
365SYSCALL_DEFINE2(stat64, const char __user *, filename,
366 struct stat64 __user *, statbuf)
367{
368 struct kstat stat;
369 int error = vfs_stat(filename, &stat);
370
371 if (!error)
372 error = cp_new_stat64(&stat, statbuf);
373
374 return error;
375}
376
377SYSCALL_DEFINE2(lstat64, const char __user *, filename,
378 struct stat64 __user *, statbuf)
379{
380 struct kstat stat;
381 int error = vfs_lstat(filename, &stat);
382
383 if (!error)
384 error = cp_new_stat64(&stat, statbuf);
385
386 return error;
387}
388
389SYSCALL_DEFINE2(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
400SYSCALL_DEFINE4(fstatat64, int, dfd, const char __user *, filename,
401 struct stat64 __user *, statbuf, int, flag)
402{
403 struct kstat stat;
404 int error;
405
406 error = vfs_fstatat(dfd, filename, &stat, flag);
407 if (error)
408 return error;
409 return cp_new_stat64(&stat, statbuf);
410}
411#endif /* __ARCH_WANT_STAT64 */
412
413/* Caller is here responsible for sufficient locking (ie. inode->i_lock) */
414void __inode_add_bytes(struct inode *inode, loff_t bytes)
415{
416 inode->i_blocks += bytes >> 9;
417 bytes &= 511;
418 inode->i_bytes += bytes;
419 if (inode->i_bytes >= 512) {
420 inode->i_blocks++;
421 inode->i_bytes -= 512;
422 }
423}
424
425void inode_add_bytes(struct inode *inode, loff_t bytes)
426{
427 spin_lock(&inode->i_lock);
428 __inode_add_bytes(inode, bytes);
429 spin_unlock(&inode->i_lock);
430}
431
432EXPORT_SYMBOL(inode_add_bytes);
433
434void inode_sub_bytes(struct inode *inode, loff_t bytes)
435{
436 spin_lock(&inode->i_lock);
437 inode->i_blocks -= bytes >> 9;
438 bytes &= 511;
439 if (inode->i_bytes < bytes) {
440 inode->i_blocks--;
441 inode->i_bytes += 512;
442 }
443 inode->i_bytes -= bytes;
444 spin_unlock(&inode->i_lock);
445}
446
447EXPORT_SYMBOL(inode_sub_bytes);
448
449loff_t inode_get_bytes(struct inode *inode)
450{
451 loff_t ret;
452
453 spin_lock(&inode->i_lock);
454 ret = (((loff_t)inode->i_blocks) << 9) + inode->i_bytes;
455 spin_unlock(&inode->i_lock);
456 return ret;
457}
458
459EXPORT_SYMBOL(inode_get_bytes);
460
461void inode_set_bytes(struct inode *inode, loff_t bytes)
462{
463 /* Caller is here responsible for sufficient locking
464 * (ie. inode->i_lock) */
465 inode->i_blocks = bytes >> 9;
466 inode->i_bytes = bytes & 511;
467}
468
469EXPORT_SYMBOL(inode_set_bytes);