Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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kernel
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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/smp_lock.h>
12#include <linux/highuid.h>
13#include <linux/fs.h>
14#include <linux/namei.h>
15#include <linux/security.h>
16#include <linux/syscalls.h>
17#include <linux/pagemap.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 = (1 << inode->i_blkbits);
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 return 0;
55}
56
57EXPORT_SYMBOL(vfs_getattr);
58
59int vfs_stat_fd(int dfd, char __user *name, struct kstat *stat)
60{
61 struct nameidata nd;
62 int error;
63
64 error = __user_walk_fd(dfd, name, LOOKUP_FOLLOW, &nd);
65 if (!error) {
66 error = vfs_getattr(nd.mnt, nd.dentry, stat);
67 path_release(&nd);
68 }
69 return error;
70}
71
72int vfs_stat(char __user *name, struct kstat *stat)
73{
74 return vfs_stat_fd(AT_FDCWD, name, stat);
75}
76
77EXPORT_SYMBOL(vfs_stat);
78
79int vfs_lstat_fd(int dfd, char __user *name, struct kstat *stat)
80{
81 struct nameidata nd;
82 int error;
83
84 error = __user_walk_fd(dfd, name, 0, &nd);
85 if (!error) {
86 error = vfs_getattr(nd.mnt, nd.dentry, stat);
87 path_release(&nd);
88 }
89 return error;
90}
91
92int vfs_lstat(char __user *name, struct kstat *stat)
93{
94 return vfs_lstat_fd(AT_FDCWD, name, stat);
95}
96
97EXPORT_SYMBOL(vfs_lstat);
98
99int vfs_fstat(unsigned int fd, struct kstat *stat)
100{
101 struct file *f = fget(fd);
102 int error = -EBADF;
103
104 if (f) {
105 error = vfs_getattr(f->f_path.mnt, f->f_path.dentry, stat);
106 fput(f);
107 }
108 return error;
109}
110
111EXPORT_SYMBOL(vfs_fstat);
112
113#ifdef __ARCH_WANT_OLD_STAT
114
115/*
116 * For backward compatibility? Maybe this should be moved
117 * into arch/i386 instead?
118 */
119static int cp_old_stat(struct kstat *stat, struct __old_kernel_stat __user * statbuf)
120{
121 static int warncount = 5;
122 struct __old_kernel_stat tmp;
123
124 if (warncount > 0) {
125 warncount--;
126 printk(KERN_WARNING "VFS: Warning: %s using old stat() call. Recompile your binary.\n",
127 current->comm);
128 } else if (warncount < 0) {
129 /* it's laughable, but... */
130 warncount = 0;
131 }
132
133 memset(&tmp, 0, sizeof(struct __old_kernel_stat));
134 tmp.st_dev = old_encode_dev(stat->dev);
135 tmp.st_ino = stat->ino;
136 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
137 return -EOVERFLOW;
138 tmp.st_mode = stat->mode;
139 tmp.st_nlink = stat->nlink;
140 if (tmp.st_nlink != stat->nlink)
141 return -EOVERFLOW;
142 SET_UID(tmp.st_uid, stat->uid);
143 SET_GID(tmp.st_gid, stat->gid);
144 tmp.st_rdev = old_encode_dev(stat->rdev);
145#if BITS_PER_LONG == 32
146 if (stat->size > MAX_NON_LFS)
147 return -EOVERFLOW;
148#endif
149 tmp.st_size = stat->size;
150 tmp.st_atime = stat->atime.tv_sec;
151 tmp.st_mtime = stat->mtime.tv_sec;
152 tmp.st_ctime = stat->ctime.tv_sec;
153 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
154}
155
156asmlinkage long sys_stat(char __user * filename, struct __old_kernel_stat __user * statbuf)
157{
158 struct kstat stat;
159 int error = vfs_stat_fd(AT_FDCWD, filename, &stat);
160
161 if (!error)
162 error = cp_old_stat(&stat, statbuf);
163
164 return error;
165}
166asmlinkage long sys_lstat(char __user * filename, struct __old_kernel_stat __user * statbuf)
167{
168 struct kstat stat;
169 int error = vfs_lstat_fd(AT_FDCWD, filename, &stat);
170
171 if (!error)
172 error = cp_old_stat(&stat, statbuf);
173
174 return error;
175}
176asmlinkage long sys_fstat(unsigned int fd, struct __old_kernel_stat __user * statbuf)
177{
178 struct kstat stat;
179 int error = vfs_fstat(fd, &stat);
180
181 if (!error)
182 error = cp_old_stat(&stat, statbuf);
183
184 return error;
185}
186
187#endif /* __ARCH_WANT_OLD_STAT */
188
189static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf)
190{
191 struct stat tmp;
192
193#if BITS_PER_LONG == 32
194 if (!old_valid_dev(stat->dev) || !old_valid_dev(stat->rdev))
195 return -EOVERFLOW;
196#else
197 if (!new_valid_dev(stat->dev) || !new_valid_dev(stat->rdev))
198 return -EOVERFLOW;
199#endif
200
201 memset(&tmp, 0, sizeof(tmp));
202#if BITS_PER_LONG == 32
203 tmp.st_dev = old_encode_dev(stat->dev);
204#else
205 tmp.st_dev = new_encode_dev(stat->dev);
206#endif
207 tmp.st_ino = stat->ino;
208 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
209 return -EOVERFLOW;
210 tmp.st_mode = stat->mode;
211 tmp.st_nlink = stat->nlink;
212 if (tmp.st_nlink != stat->nlink)
213 return -EOVERFLOW;
214 SET_UID(tmp.st_uid, stat->uid);
215 SET_GID(tmp.st_gid, stat->gid);
216#if BITS_PER_LONG == 32
217 tmp.st_rdev = old_encode_dev(stat->rdev);
218#else
219 tmp.st_rdev = new_encode_dev(stat->rdev);
220#endif
221#if BITS_PER_LONG == 32
222 if (stat->size > MAX_NON_LFS)
223 return -EOVERFLOW;
224#endif
225 tmp.st_size = stat->size;
226 tmp.st_atime = stat->atime.tv_sec;
227 tmp.st_mtime = stat->mtime.tv_sec;
228 tmp.st_ctime = stat->ctime.tv_sec;
229#ifdef STAT_HAVE_NSEC
230 tmp.st_atime_nsec = stat->atime.tv_nsec;
231 tmp.st_mtime_nsec = stat->mtime.tv_nsec;
232 tmp.st_ctime_nsec = stat->ctime.tv_nsec;
233#endif
234 tmp.st_blocks = stat->blocks;
235 tmp.st_blksize = stat->blksize;
236 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
237}
238
239asmlinkage long sys_newstat(char __user *filename, struct stat __user *statbuf)
240{
241 struct kstat stat;
242 int error = vfs_stat_fd(AT_FDCWD, filename, &stat);
243
244 if (!error)
245 error = cp_new_stat(&stat, statbuf);
246
247 return error;
248}
249
250asmlinkage long sys_newlstat(char __user *filename, struct stat __user *statbuf)
251{
252 struct kstat stat;
253 int error = vfs_lstat_fd(AT_FDCWD, filename, &stat);
254
255 if (!error)
256 error = cp_new_stat(&stat, statbuf);
257
258 return error;
259}
260
261#if !defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_SYS_NEWFSTATAT)
262asmlinkage long sys_newfstatat(int dfd, char __user *filename,
263 struct stat __user *statbuf, int flag)
264{
265 struct kstat stat;
266 int error = -EINVAL;
267
268 if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0)
269 goto out;
270
271 if (flag & AT_SYMLINK_NOFOLLOW)
272 error = vfs_lstat_fd(dfd, filename, &stat);
273 else
274 error = vfs_stat_fd(dfd, filename, &stat);
275
276 if (!error)
277 error = cp_new_stat(&stat, statbuf);
278
279out:
280 return error;
281}
282#endif
283
284asmlinkage long sys_newfstat(unsigned int fd, struct stat __user *statbuf)
285{
286 struct kstat stat;
287 int error = vfs_fstat(fd, &stat);
288
289 if (!error)
290 error = cp_new_stat(&stat, statbuf);
291
292 return error;
293}
294
295asmlinkage long sys_readlinkat(int dfd, const char __user *path,
296 char __user *buf, int bufsiz)
297{
298 struct nameidata nd;
299 int error;
300
301 if (bufsiz <= 0)
302 return -EINVAL;
303
304 error = __user_walk_fd(dfd, path, 0, &nd);
305 if (!error) {
306 struct inode * inode = nd.dentry->d_inode;
307
308 error = -EINVAL;
309 if (inode->i_op && inode->i_op->readlink) {
310 error = security_inode_readlink(nd.dentry);
311 if (!error) {
312 touch_atime(nd.mnt, nd.dentry);
313 error = inode->i_op->readlink(nd.dentry, buf, bufsiz);
314 }
315 }
316 path_release(&nd);
317 }
318 return error;
319}
320
321asmlinkage long sys_readlink(const char __user *path, char __user *buf,
322 int bufsiz)
323{
324 return sys_readlinkat(AT_FDCWD, path, buf, bufsiz);
325}
326
327
328/* ---------- LFS-64 ----------- */
329#ifdef __ARCH_WANT_STAT64
330
331static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf)
332{
333 struct stat64 tmp;
334
335 memset(&tmp, 0, sizeof(struct stat64));
336#ifdef CONFIG_MIPS
337 /* mips has weird padding, so we don't get 64 bits there */
338 if (!new_valid_dev(stat->dev) || !new_valid_dev(stat->rdev))
339 return -EOVERFLOW;
340 tmp.st_dev = new_encode_dev(stat->dev);
341 tmp.st_rdev = new_encode_dev(stat->rdev);
342#else
343 tmp.st_dev = huge_encode_dev(stat->dev);
344 tmp.st_rdev = huge_encode_dev(stat->rdev);
345#endif
346 tmp.st_ino = stat->ino;
347 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
348 return -EOVERFLOW;
349#ifdef STAT64_HAS_BROKEN_ST_INO
350 tmp.__st_ino = stat->ino;
351#endif
352 tmp.st_mode = stat->mode;
353 tmp.st_nlink = stat->nlink;
354 tmp.st_uid = stat->uid;
355 tmp.st_gid = stat->gid;
356 tmp.st_atime = stat->atime.tv_sec;
357 tmp.st_atime_nsec = stat->atime.tv_nsec;
358 tmp.st_mtime = stat->mtime.tv_sec;
359 tmp.st_mtime_nsec = stat->mtime.tv_nsec;
360 tmp.st_ctime = stat->ctime.tv_sec;
361 tmp.st_ctime_nsec = stat->ctime.tv_nsec;
362 tmp.st_size = stat->size;
363 tmp.st_blocks = stat->blocks;
364 tmp.st_blksize = stat->blksize;
365 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
366}
367
368asmlinkage long sys_stat64(char __user * filename, struct stat64 __user * statbuf)
369{
370 struct kstat stat;
371 int error = vfs_stat(filename, &stat);
372
373 if (!error)
374 error = cp_new_stat64(&stat, statbuf);
375
376 return error;
377}
378asmlinkage long sys_lstat64(char __user * filename, 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}
388asmlinkage long sys_fstat64(unsigned long fd, struct stat64 __user * statbuf)
389{
390 struct kstat stat;
391 int error = vfs_fstat(fd, &stat);
392
393 if (!error)
394 error = cp_new_stat64(&stat, statbuf);
395
396 return error;
397}
398
399asmlinkage long sys_fstatat64(int dfd, char __user *filename,
400 struct stat64 __user *statbuf, int flag)
401{
402 struct kstat stat;
403 int error = -EINVAL;
404
405 if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0)
406 goto out;
407
408 if (flag & AT_SYMLINK_NOFOLLOW)
409 error = vfs_lstat_fd(dfd, filename, &stat);
410 else
411 error = vfs_stat_fd(dfd, filename, &stat);
412
413 if (!error)
414 error = cp_new_stat64(&stat, statbuf);
415
416out:
417 return error;
418}
419#endif /* __ARCH_WANT_STAT64 */
420
421void inode_add_bytes(struct inode *inode, loff_t bytes)
422{
423 spin_lock(&inode->i_lock);
424 inode->i_blocks += bytes >> 9;
425 bytes &= 511;
426 inode->i_bytes += bytes;
427 if (inode->i_bytes >= 512) {
428 inode->i_blocks++;
429 inode->i_bytes -= 512;
430 }
431 spin_unlock(&inode->i_lock);
432}
433
434EXPORT_SYMBOL(inode_add_bytes);
435
436void inode_sub_bytes(struct inode *inode, loff_t bytes)
437{
438 spin_lock(&inode->i_lock);
439 inode->i_blocks -= bytes >> 9;
440 bytes &= 511;
441 if (inode->i_bytes < bytes) {
442 inode->i_blocks--;
443 inode->i_bytes += 512;
444 }
445 inode->i_bytes -= bytes;
446 spin_unlock(&inode->i_lock);
447}
448
449EXPORT_SYMBOL(inode_sub_bytes);
450
451loff_t inode_get_bytes(struct inode *inode)
452{
453 loff_t ret;
454
455 spin_lock(&inode->i_lock);
456 ret = (((loff_t)inode->i_blocks) << 9) + inode->i_bytes;
457 spin_unlock(&inode->i_lock);
458 return ret;
459}
460
461EXPORT_SYMBOL(inode_get_bytes);
462
463void inode_set_bytes(struct inode *inode, loff_t bytes)
464{
465 /* Caller is here responsible for sufficient locking
466 * (ie. inode->i_lock) */
467 inode->i_blocks = bytes >> 9;
468 inode->i_bytes = bytes & 511;
469}
470
471EXPORT_SYMBOL(inode_set_bytes);