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/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
66int vfs_stat_fd(int dfd, char __user *name, struct kstat *stat)
67{
68 struct nameidata nd;
69 int error;
70
71 error = __user_walk_fd(dfd, name, LOOKUP_FOLLOW, &nd);
72 if (!error) {
73 error = vfs_getattr(nd.mnt, nd.dentry, stat);
74 path_release(&nd);
75 }
76 return error;
77}
78
79int vfs_stat(char __user *name, struct kstat *stat)
80{
81 return vfs_stat_fd(AT_FDCWD, name, stat);
82}
83
84EXPORT_SYMBOL(vfs_stat);
85
86int vfs_lstat_fd(int dfd, char __user *name, struct kstat *stat)
87{
88 struct nameidata nd;
89 int error;
90
91 error = __user_walk_fd(dfd, name, 0, &nd);
92 if (!error) {
93 error = vfs_getattr(nd.mnt, nd.dentry, stat);
94 path_release(&nd);
95 }
96 return error;
97}
98
99int vfs_lstat(char __user *name, struct kstat *stat)
100{
101 return vfs_lstat_fd(AT_FDCWD, name, stat);
102}
103
104EXPORT_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;
164 int error = vfs_stat_fd(AT_FDCWD, filename, &stat);
165
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;
174 int error = vfs_lstat_fd(AT_FDCWD, filename, &stat);
175
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
242asmlinkage 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
253asmlinkage long sys_newlstat(char __user *filename, struct stat __user *statbuf)
254{
255 struct kstat stat;
256 int error = vfs_lstat_fd(AT_FDCWD, filename, &stat);
257
258 if (!error)
259 error = cp_new_stat(&stat, statbuf);
260
261 return error;
262}
263
264asmlinkage long sys_newfstatat(int dfd, char __user *filename,
265 struct stat __user *statbuf, int flag)
266{
267 struct kstat stat;
268 int error = -EINVAL;
269
270 if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0)
271 goto out;
272
273 if (flag & AT_SYMLINK_NOFOLLOW)
274 error = vfs_lstat_fd(dfd, filename, &stat);
275 else
276 error = vfs_stat_fd(dfd, filename, &stat);
277
278 if (!error)
279 error = cp_new_stat(&stat, statbuf);
280
281out:
282 return error;
283}
284
285asmlinkage long sys_newfstat(unsigned int fd, struct stat __user *statbuf)
286{
287 struct kstat stat;
288 int error = vfs_fstat(fd, &stat);
289
290 if (!error)
291 error = cp_new_stat(&stat, statbuf);
292
293 return error;
294}
295
296asmlinkage long sys_readlinkat(int dfd, const char __user *path,
297 char __user *buf, int bufsiz)
298{
299 struct nameidata nd;
300 int error;
301
302 if (bufsiz <= 0)
303 return -EINVAL;
304
305 error = __user_walk_fd(dfd, path, 0, &nd);
306 if (!error) {
307 struct inode * inode = nd.dentry->d_inode;
308
309 error = -EINVAL;
310 if (inode->i_op && inode->i_op->readlink) {
311 error = security_inode_readlink(nd.dentry);
312 if (!error) {
313 touch_atime(nd.mnt, nd.dentry);
314 error = inode->i_op->readlink(nd.dentry, buf, bufsiz);
315 }
316 }
317 path_release(&nd);
318 }
319 return error;
320}
321
322asmlinkage long sys_readlink(const char __user *path, char __user *buf,
323 int bufsiz)
324{
325 return sys_readlinkat(AT_FDCWD, path, buf, bufsiz);
326}
327
328
329/* ---------- LFS-64 ----------- */
330#ifdef __ARCH_WANT_STAT64
331
332static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf)
333{
334 struct stat64 tmp;
335
336 memset(&tmp, 0, sizeof(struct stat64));
337#ifdef CONFIG_MIPS
338 /* mips has weird padding, so we don't get 64 bits there */
339 if (!new_valid_dev(stat->dev) || !new_valid_dev(stat->rdev))
340 return -EOVERFLOW;
341 tmp.st_dev = new_encode_dev(stat->dev);
342 tmp.st_rdev = new_encode_dev(stat->rdev);
343#else
344 tmp.st_dev = huge_encode_dev(stat->dev);
345 tmp.st_rdev = huge_encode_dev(stat->rdev);
346#endif
347 tmp.st_ino = stat->ino;
348#ifdef STAT64_HAS_BROKEN_ST_INO
349 tmp.__st_ino = stat->ino;
350#endif
351 tmp.st_mode = stat->mode;
352 tmp.st_nlink = stat->nlink;
353 tmp.st_uid = stat->uid;
354 tmp.st_gid = stat->gid;
355 tmp.st_atime = stat->atime.tv_sec;
356 tmp.st_atime_nsec = stat->atime.tv_nsec;
357 tmp.st_mtime = stat->mtime.tv_sec;
358 tmp.st_mtime_nsec = stat->mtime.tv_nsec;
359 tmp.st_ctime = stat->ctime.tv_sec;
360 tmp.st_ctime_nsec = stat->ctime.tv_nsec;
361 tmp.st_size = stat->size;
362 tmp.st_blocks = stat->blocks;
363 tmp.st_blksize = stat->blksize;
364 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
365}
366
367asmlinkage long sys_stat64(char __user * filename, struct stat64 __user * statbuf)
368{
369 struct kstat stat;
370 int error = vfs_stat(filename, &stat);
371
372 if (!error)
373 error = cp_new_stat64(&stat, statbuf);
374
375 return error;
376}
377asmlinkage long sys_lstat64(char __user * filename, struct stat64 __user * statbuf)
378{
379 struct kstat stat;
380 int error = vfs_lstat(filename, &stat);
381
382 if (!error)
383 error = cp_new_stat64(&stat, statbuf);
384
385 return error;
386}
387asmlinkage long sys_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#endif /* __ARCH_WANT_STAT64 */
399
400void inode_add_bytes(struct inode *inode, loff_t bytes)
401{
402 spin_lock(&inode->i_lock);
403 inode->i_blocks += bytes >> 9;
404 bytes &= 511;
405 inode->i_bytes += bytes;
406 if (inode->i_bytes >= 512) {
407 inode->i_blocks++;
408 inode->i_bytes -= 512;
409 }
410 spin_unlock(&inode->i_lock);
411}
412
413EXPORT_SYMBOL(inode_add_bytes);
414
415void inode_sub_bytes(struct inode *inode, loff_t bytes)
416{
417 spin_lock(&inode->i_lock);
418 inode->i_blocks -= bytes >> 9;
419 bytes &= 511;
420 if (inode->i_bytes < bytes) {
421 inode->i_blocks--;
422 inode->i_bytes += 512;
423 }
424 inode->i_bytes -= bytes;
425 spin_unlock(&inode->i_lock);
426}
427
428EXPORT_SYMBOL(inode_sub_bytes);
429
430loff_t inode_get_bytes(struct inode *inode)
431{
432 loff_t ret;
433
434 spin_lock(&inode->i_lock);
435 ret = (((loff_t)inode->i_blocks) << 9) + inode->i_bytes;
436 spin_unlock(&inode->i_lock);
437 return ret;
438}
439
440EXPORT_SYMBOL(inode_get_bytes);
441
442void inode_set_bytes(struct inode *inode, loff_t bytes)
443{
444 /* Caller is here responsible for sufficient locking
445 * (ie. inode->i_lock) */
446 inode->i_blocks = bytes >> 9;
447 inode->i_bytes = bytes & 511;
448}
449
450EXPORT_SYMBOL(inode_set_bytes);