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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
22void 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
39EXPORT_SYMBOL(generic_fillattr);
40
41int 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
64EXPORT_SYMBOL(vfs_getattr);
65
Ulrich Drepper5590ff02006-01-18 17:43:53 -080066int vfs_stat_fd(int dfd, char __user *name, struct kstat *stat)
Linus Torvalds1da177e2005-04-16 15:20:36 -070067{
68 struct nameidata nd;
69 int error;
70
Ulrich Drepper5590ff02006-01-18 17:43:53 -080071 error = __user_walk_fd(dfd, name, LOOKUP_FOLLOW, &nd);
Linus Torvalds1da177e2005-04-16 15:20:36 -070072 if (!error) {
73 error = vfs_getattr(nd.mnt, nd.dentry, stat);
74 path_release(&nd);
75 }
76 return error;
77}
78
Ulrich Drepper5590ff02006-01-18 17:43:53 -080079int vfs_stat(char __user *name, struct kstat *stat)
80{
81 return vfs_stat_fd(AT_FDCWD, name, stat);
82}
83
Linus Torvalds1da177e2005-04-16 15:20:36 -070084EXPORT_SYMBOL(vfs_stat);
85
Ulrich Drepper5590ff02006-01-18 17:43:53 -080086int vfs_lstat_fd(int dfd, char __user *name, struct kstat *stat)
Linus Torvalds1da177e2005-04-16 15:20:36 -070087{
88 struct nameidata nd;
89 int error;
90
Ulrich Drepper5590ff02006-01-18 17:43:53 -080091 error = __user_walk_fd(dfd, name, 0, &nd);
Linus Torvalds1da177e2005-04-16 15:20:36 -070092 if (!error) {
93 error = vfs_getattr(nd.mnt, nd.dentry, stat);
94 path_release(&nd);
95 }
96 return error;
97}
98
Ulrich Drepper5590ff02006-01-18 17:43:53 -080099int vfs_lstat(char __user *name, struct kstat *stat)
100{
101 return vfs_lstat_fd(AT_FDCWD, name, stat);
102}
103
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104EXPORT_SYMBOL(vfs_lstat);
105
106int 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
118EXPORT_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 */
126static 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
161asmlinkage long sys_stat(char __user * filename, struct __old_kernel_stat __user * statbuf)
162{
163 struct kstat stat;
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800164 int error = vfs_stat_fd(AT_FDCWD, filename, &stat);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165
166 if (!error)
167 error = cp_old_stat(&stat, statbuf);
168
169 return error;
170}
171asmlinkage long sys_lstat(char __user * filename, struct __old_kernel_stat __user * statbuf)
172{
173 struct kstat stat;
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800174 int error = vfs_lstat_fd(AT_FDCWD, filename, &stat);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175
176 if (!error)
177 error = cp_old_stat(&stat, statbuf);
178
179 return error;
180}
181asmlinkage 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
194static 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
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800242asmlinkage long sys_newstat(char __user *filename, struct stat __user *statbuf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243{
244 struct kstat stat;
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800245 int error = vfs_stat_fd(AT_FDCWD, filename, &stat);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246
247 if (!error)
248 error = cp_new_stat(&stat, statbuf);
249
250 return error;
251}
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800252
253asmlinkage long sys_newlstat(char __user *filename, struct stat __user *statbuf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254{
255 struct kstat stat;
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800256 int error = vfs_lstat_fd(AT_FDCWD, filename, &stat);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257
258 if (!error)
259 error = cp_new_stat(&stat, statbuf);
260
261 return error;
262}
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800263
Ulrich Dreppercff2b762006-02-11 17:55:47 -0800264#ifndef __ARCH_WANT_STAT64
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800265asmlinkage long sys_newfstatat(int dfd, char __user *filename,
266 struct stat __user *statbuf, int flag)
267{
268 struct kstat stat;
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);
278
279 if (!error)
280 error = cp_new_stat(&stat, statbuf);
281
282out:
283 return error;
284}
Ulrich Dreppercff2b762006-02-11 17:55:47 -0800285#endif
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800286
287asmlinkage long sys_newfstat(unsigned int fd, struct stat __user *statbuf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700288{
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
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800298asmlinkage long sys_readlinkat(int dfd, const char __user *path,
299 char __user *buf, int bufsiz)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700300{
301 struct nameidata nd;
302 int error;
303
304 if (bufsiz <= 0)
305 return -EINVAL;
306
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800307 error = __user_walk_fd(dfd, path, 0, &nd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700308 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
Ulrich Drepper5590ff02006-01-18 17:43:53 -0800324asmlinkage 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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700330
331/* ---------- LFS-64 ----------- */
332#ifdef __ARCH_WANT_STAT64
333
334static 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
369asmlinkage 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}
379asmlinkage 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}
389asmlinkage 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
Ulrich Dreppercff2b762006-02-11 17:55:47 -0800400asmlinkage 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
417out:
418 return error;
419}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700420#endif /* __ARCH_WANT_STAT64 */
421
422void 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
435EXPORT_SYMBOL(inode_add_bytes);
436
437void 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
450EXPORT_SYMBOL(inode_sub_bytes);
451
452loff_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
462EXPORT_SYMBOL(inode_get_bytes);
463
464void 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
472EXPORT_SYMBOL(inode_set_bytes);