Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
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/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 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 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
144 return -EOVERFLOW;
145 tmp.st_mode = stat->mode;
146 tmp.st_nlink = stat->nlink;
147 if (tmp.st_nlink != stat->nlink)
148 return -EOVERFLOW;
149 SET_UID(tmp.st_uid, stat->uid);
150 SET_GID(tmp.st_gid, stat->gid);
151 tmp.st_rdev = old_encode_dev(stat->rdev);
152#if BITS_PER_LONG == 32
153 if (stat->size > MAX_NON_LFS)
154 return -EOVERFLOW;
155#endif
156 tmp.st_size = stat->size;
157 tmp.st_atime = stat->atime.tv_sec;
158 tmp.st_mtime = stat->mtime.tv_sec;
159 tmp.st_ctime = stat->ctime.tv_sec;
160 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
161}
162
163asmlinkage long sys_stat(char __user * filename, struct __old_kernel_stat __user * statbuf)
164{
165 struct kstat stat;
166 int error = vfs_stat_fd(AT_FDCWD, filename, &stat);
167
168 if (!error)
169 error = cp_old_stat(&stat, statbuf);
170
171 return error;
172}
173asmlinkage long sys_lstat(char __user * filename, struct __old_kernel_stat __user * statbuf)
174{
175 struct kstat stat;
176 int error = vfs_lstat_fd(AT_FDCWD, filename, &stat);
177
178 if (!error)
179 error = cp_old_stat(&stat, statbuf);
180
181 return error;
182}
183asmlinkage long sys_fstat(unsigned int fd, struct __old_kernel_stat __user * statbuf)
184{
185 struct kstat stat;
186 int error = vfs_fstat(fd, &stat);
187
188 if (!error)
189 error = cp_old_stat(&stat, statbuf);
190
191 return error;
192}
193
194#endif /* __ARCH_WANT_OLD_STAT */
195
196static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf)
197{
198 struct stat tmp;
199
200#if BITS_PER_LONG == 32
201 if (!old_valid_dev(stat->dev) || !old_valid_dev(stat->rdev))
202 return -EOVERFLOW;
203#else
204 if (!new_valid_dev(stat->dev) || !new_valid_dev(stat->rdev))
205 return -EOVERFLOW;
206#endif
207
208 memset(&tmp, 0, sizeof(tmp));
209#if BITS_PER_LONG == 32
210 tmp.st_dev = old_encode_dev(stat->dev);
211#else
212 tmp.st_dev = new_encode_dev(stat->dev);
213#endif
214 tmp.st_ino = stat->ino;
215 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
216 return -EOVERFLOW;
217 tmp.st_mode = stat->mode;
218 tmp.st_nlink = stat->nlink;
219 if (tmp.st_nlink != stat->nlink)
220 return -EOVERFLOW;
221 SET_UID(tmp.st_uid, stat->uid);
222 SET_GID(tmp.st_gid, stat->gid);
223#if BITS_PER_LONG == 32
224 tmp.st_rdev = old_encode_dev(stat->rdev);
225#else
226 tmp.st_rdev = new_encode_dev(stat->rdev);
227#endif
228#if BITS_PER_LONG == 32
229 if (stat->size > MAX_NON_LFS)
230 return -EOVERFLOW;
231#endif
232 tmp.st_size = stat->size;
233 tmp.st_atime = stat->atime.tv_sec;
234 tmp.st_mtime = stat->mtime.tv_sec;
235 tmp.st_ctime = stat->ctime.tv_sec;
236#ifdef STAT_HAVE_NSEC
237 tmp.st_atime_nsec = stat->atime.tv_nsec;
238 tmp.st_mtime_nsec = stat->mtime.tv_nsec;
239 tmp.st_ctime_nsec = stat->ctime.tv_nsec;
240#endif
241 tmp.st_blocks = stat->blocks;
242 tmp.st_blksize = stat->blksize;
243 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
244}
245
246asmlinkage long sys_newstat(char __user *filename, struct stat __user *statbuf)
247{
248 struct kstat stat;
249 int error = vfs_stat_fd(AT_FDCWD, filename, &stat);
250
251 if (!error)
252 error = cp_new_stat(&stat, statbuf);
253
254 return error;
255}
256
257asmlinkage long sys_newlstat(char __user *filename, struct stat __user *statbuf)
258{
259 struct kstat stat;
260 int error = vfs_lstat_fd(AT_FDCWD, filename, &stat);
261
262 if (!error)
263 error = cp_new_stat(&stat, statbuf);
264
265 return error;
266}
267
268#if !defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_SYS_NEWFSTATAT)
269asmlinkage long sys_newfstatat(int dfd, char __user *filename,
270 struct stat __user *statbuf, int flag)
271{
272 struct kstat stat;
273 int error = -EINVAL;
274
275 if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0)
276 goto out;
277
278 if (flag & AT_SYMLINK_NOFOLLOW)
279 error = vfs_lstat_fd(dfd, filename, &stat);
280 else
281 error = vfs_stat_fd(dfd, filename, &stat);
282
283 if (!error)
284 error = cp_new_stat(&stat, statbuf);
285
286out:
287 return error;
288}
289#endif
290
291asmlinkage long sys_newfstat(unsigned int fd, struct stat __user *statbuf)
292{
293 struct kstat stat;
294 int error = vfs_fstat(fd, &stat);
295
296 if (!error)
297 error = cp_new_stat(&stat, statbuf);
298
299 return error;
300}
301
302asmlinkage long sys_readlinkat(int dfd, const char __user *path,
303 char __user *buf, int bufsiz)
304{
305 struct nameidata nd;
306 int error;
307
308 if (bufsiz <= 0)
309 return -EINVAL;
310
311 error = __user_walk_fd(dfd, path, 0, &nd);
312 if (!error) {
313 struct inode * inode = nd.dentry->d_inode;
314
315 error = -EINVAL;
316 if (inode->i_op && inode->i_op->readlink) {
317 error = security_inode_readlink(nd.dentry);
318 if (!error) {
319 touch_atime(nd.mnt, nd.dentry);
320 error = inode->i_op->readlink(nd.dentry, buf, bufsiz);
321 }
322 }
323 path_release(&nd);
324 }
325 return error;
326}
327
328asmlinkage long sys_readlink(const char __user *path, char __user *buf,
329 int bufsiz)
330{
331 return sys_readlinkat(AT_FDCWD, path, buf, bufsiz);
332}
333
334
335/* ---------- LFS-64 ----------- */
336#ifdef __ARCH_WANT_STAT64
337
338static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf)
339{
340 struct stat64 tmp;
341
342 memset(&tmp, 0, sizeof(struct stat64));
343#ifdef CONFIG_MIPS
344 /* mips has weird padding, so we don't get 64 bits there */
345 if (!new_valid_dev(stat->dev) || !new_valid_dev(stat->rdev))
346 return -EOVERFLOW;
347 tmp.st_dev = new_encode_dev(stat->dev);
348 tmp.st_rdev = new_encode_dev(stat->rdev);
349#else
350 tmp.st_dev = huge_encode_dev(stat->dev);
351 tmp.st_rdev = huge_encode_dev(stat->rdev);
352#endif
353 tmp.st_ino = stat->ino;
354 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
355 return -EOVERFLOW;
356#ifdef STAT64_HAS_BROKEN_ST_INO
357 tmp.__st_ino = stat->ino;
358#endif
359 tmp.st_mode = stat->mode;
360 tmp.st_nlink = stat->nlink;
361 tmp.st_uid = stat->uid;
362 tmp.st_gid = stat->gid;
363 tmp.st_atime = stat->atime.tv_sec;
364 tmp.st_atime_nsec = stat->atime.tv_nsec;
365 tmp.st_mtime = stat->mtime.tv_sec;
366 tmp.st_mtime_nsec = stat->mtime.tv_nsec;
367 tmp.st_ctime = stat->ctime.tv_sec;
368 tmp.st_ctime_nsec = stat->ctime.tv_nsec;
369 tmp.st_size = stat->size;
370 tmp.st_blocks = stat->blocks;
371 tmp.st_blksize = stat->blksize;
372 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
373}
374
375asmlinkage long sys_stat64(char __user * filename, struct stat64 __user * statbuf)
376{
377 struct kstat stat;
378 int error = vfs_stat(filename, &stat);
379
380 if (!error)
381 error = cp_new_stat64(&stat, statbuf);
382
383 return error;
384}
385asmlinkage long sys_lstat64(char __user * filename, struct stat64 __user * statbuf)
386{
387 struct kstat stat;
388 int error = vfs_lstat(filename, &stat);
389
390 if (!error)
391 error = cp_new_stat64(&stat, statbuf);
392
393 return error;
394}
395asmlinkage long sys_fstat64(unsigned long fd, struct stat64 __user * statbuf)
396{
397 struct kstat stat;
398 int error = vfs_fstat(fd, &stat);
399
400 if (!error)
401 error = cp_new_stat64(&stat, statbuf);
402
403 return error;
404}
405
406asmlinkage long sys_fstatat64(int dfd, char __user *filename,
407 struct stat64 __user *statbuf, int flag)
408{
409 struct kstat stat;
410 int error = -EINVAL;
411
412 if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0)
413 goto out;
414
415 if (flag & AT_SYMLINK_NOFOLLOW)
416 error = vfs_lstat_fd(dfd, filename, &stat);
417 else
418 error = vfs_stat_fd(dfd, filename, &stat);
419
420 if (!error)
421 error = cp_new_stat64(&stat, statbuf);
422
423out:
424 return error;
425}
426#endif /* __ARCH_WANT_STAT64 */
427
428void inode_add_bytes(struct inode *inode, loff_t bytes)
429{
430 spin_lock(&inode->i_lock);
431 inode->i_blocks += bytes >> 9;
432 bytes &= 511;
433 inode->i_bytes += bytes;
434 if (inode->i_bytes >= 512) {
435 inode->i_blocks++;
436 inode->i_bytes -= 512;
437 }
438 spin_unlock(&inode->i_lock);
439}
440
441EXPORT_SYMBOL(inode_add_bytes);
442
443void inode_sub_bytes(struct inode *inode, loff_t bytes)
444{
445 spin_lock(&inode->i_lock);
446 inode->i_blocks -= bytes >> 9;
447 bytes &= 511;
448 if (inode->i_bytes < bytes) {
449 inode->i_blocks--;
450 inode->i_bytes += 512;
451 }
452 inode->i_bytes -= bytes;
453 spin_unlock(&inode->i_lock);
454}
455
456EXPORT_SYMBOL(inode_sub_bytes);
457
458loff_t inode_get_bytes(struct inode *inode)
459{
460 loff_t ret;
461
462 spin_lock(&inode->i_lock);
463 ret = (((loff_t)inode->i_blocks) << 9) + inode->i_bytes;
464 spin_unlock(&inode->i_lock);
465 return ret;
466}
467
468EXPORT_SYMBOL(inode_get_bytes);
469
470void inode_set_bytes(struct inode *inode, loff_t bytes)
471{
472 /* Caller is here responsible for sufficient locking
473 * (ie. inode->i_lock) */
474 inode->i_blocks = bytes >> 9;
475 inode->i_bytes = bytes & 511;
476}
477
478EXPORT_SYMBOL(inode_set_bytes);