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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/fs/stat.c
4 *
5 * Copyright (C) 1991, 1992 Linus Torvalds
6 */
7
8#include <linux/export.h>
9#include <linux/mm.h>
10#include <linux/errno.h>
11#include <linux/file.h>
12#include <linux/highuid.h>
13#include <linux/fs.h>
14#include <linux/namei.h>
15#include <linux/security.h>
16#include <linux/cred.h>
17#include <linux/syscalls.h>
18#include <linux/pagemap.h>
19#include <linux/compat.h>
20
21#include <linux/uaccess.h>
22#include <asm/unistd.h>
23
24#include "internal.h"
25#include "mount.h"
26
27/**
28 * generic_fillattr - Fill in the basic attributes from the inode struct
29 * @inode: Inode to use as the source
30 * @stat: Where to fill in the attributes
31 *
32 * Fill in the basic attributes in the kstat structure from data that's to be
33 * found on the VFS inode structure. This is the default if no getattr inode
34 * operation is supplied.
35 */
36void generic_fillattr(struct inode *inode, struct kstat *stat)
37{
38 stat->dev = inode->i_sb->s_dev;
39 stat->ino = inode->i_ino;
40 stat->mode = inode->i_mode;
41 stat->nlink = inode->i_nlink;
42 stat->uid = inode->i_uid;
43 stat->gid = inode->i_gid;
44 stat->rdev = inode->i_rdev;
45 stat->size = i_size_read(inode);
46 stat->atime = inode->i_atime;
47 stat->mtime = inode->i_mtime;
48 stat->ctime = inode->i_ctime;
49 stat->blksize = i_blocksize(inode);
50 stat->blocks = inode->i_blocks;
51}
52EXPORT_SYMBOL(generic_fillattr);
53
54/**
55 * vfs_getattr_nosec - getattr without security checks
56 * @path: file to get attributes from
57 * @stat: structure to return attributes in
58 * @request_mask: STATX_xxx flags indicating what the caller wants
59 * @query_flags: Query mode (KSTAT_QUERY_FLAGS)
60 *
61 * Get attributes without calling security_inode_getattr.
62 *
63 * Currently the only caller other than vfs_getattr is internal to the
64 * filehandle lookup code, which uses only the inode number and returns no
65 * attributes to any user. Any other code probably wants vfs_getattr.
66 */
67int vfs_getattr_nosec(const struct path *path, struct kstat *stat,
68 u32 request_mask, unsigned int query_flags)
69{
70 struct inode *inode = d_backing_inode(path->dentry);
71
72 memset(stat, 0, sizeof(*stat));
73 stat->result_mask |= STATX_BASIC_STATS;
74 query_flags &= KSTAT_QUERY_FLAGS;
75
76 /* allow the fs to override these if it really wants to */
77 /* SB_NOATIME means filesystem supplies dummy atime value */
78 if (inode->i_sb->s_flags & SB_NOATIME)
79 stat->result_mask &= ~STATX_ATIME;
80 if (IS_AUTOMOUNT(inode))
81 stat->attributes |= STATX_ATTR_AUTOMOUNT;
82
83 if (IS_DAX(inode))
84 stat->attributes |= STATX_ATTR_DAX;
85
86 if (inode->i_op->getattr)
87 return inode->i_op->getattr(path, stat, request_mask,
88 query_flags);
89
90 generic_fillattr(inode, stat);
91 return 0;
92}
93EXPORT_SYMBOL(vfs_getattr_nosec);
94
95/*
96 * vfs_getattr - Get the enhanced basic attributes of a file
97 * @path: The file of interest
98 * @stat: Where to return the statistics
99 * @request_mask: STATX_xxx flags indicating what the caller wants
100 * @query_flags: Query mode (KSTAT_QUERY_FLAGS)
101 *
102 * Ask the filesystem for a file's attributes. The caller must indicate in
103 * request_mask and query_flags to indicate what they want.
104 *
105 * If the file is remote, the filesystem can be forced to update the attributes
106 * from the backing store by passing AT_STATX_FORCE_SYNC in query_flags or can
107 * suppress the update by passing AT_STATX_DONT_SYNC.
108 *
109 * Bits must have been set in request_mask to indicate which attributes the
110 * caller wants retrieving. Any such attribute not requested may be returned
111 * anyway, but the value may be approximate, and, if remote, may not have been
112 * synchronised with the server.
113 *
114 * 0 will be returned on success, and a -ve error code if unsuccessful.
115 */
116int vfs_getattr(const struct path *path, struct kstat *stat,
117 u32 request_mask, unsigned int query_flags)
118{
119 int retval;
120
121 retval = security_inode_getattr(path);
122 if (retval)
123 return retval;
124 return vfs_getattr_nosec(path, stat, request_mask, query_flags);
125}
126EXPORT_SYMBOL(vfs_getattr);
127
128/**
129 * vfs_statx_fd - Get the enhanced basic attributes by file descriptor
130 * @fd: The file descriptor referring to the file of interest
131 * @stat: The result structure to fill in.
132 * @request_mask: STATX_xxx flags indicating what the caller wants
133 * @query_flags: Query mode (KSTAT_QUERY_FLAGS)
134 *
135 * This function is a wrapper around vfs_getattr(). The main difference is
136 * that it uses a file descriptor to determine the file location.
137 *
138 * 0 will be returned on success, and a -ve error code if unsuccessful.
139 */
140int vfs_statx_fd(unsigned int fd, struct kstat *stat,
141 u32 request_mask, unsigned int query_flags)
142{
143 struct fd f;
144 int error = -EBADF;
145
146 if (query_flags & ~KSTAT_QUERY_FLAGS)
147 return -EINVAL;
148
149 f = fdget_raw(fd);
150 if (f.file) {
151 error = vfs_getattr(&f.file->f_path, stat,
152 request_mask, query_flags);
153 fdput(f);
154 }
155 return error;
156}
157EXPORT_SYMBOL(vfs_statx_fd);
158
159static inline unsigned vfs_stat_set_lookup_flags(unsigned *lookup_flags,
160 int flags)
161{
162 if ((flags & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT |
163 AT_EMPTY_PATH | KSTAT_QUERY_FLAGS)) != 0)
164 return -EINVAL;
165
166 *lookup_flags = LOOKUP_FOLLOW | LOOKUP_AUTOMOUNT;
167 if (flags & AT_SYMLINK_NOFOLLOW)
168 *lookup_flags &= ~LOOKUP_FOLLOW;
169 if (flags & AT_NO_AUTOMOUNT)
170 *lookup_flags &= ~LOOKUP_AUTOMOUNT;
171 if (flags & AT_EMPTY_PATH)
172 *lookup_flags |= LOOKUP_EMPTY;
173
174 return 0;
175}
176
177/**
178 * vfs_statx - Get basic and extra attributes by filename
179 * @dfd: A file descriptor representing the base dir for a relative filename
180 * @filename: The name of the file of interest
181 * @flags: Flags to control the query
182 * @stat: The result structure to fill in.
183 * @request_mask: STATX_xxx flags indicating what the caller wants
184 *
185 * This function is a wrapper around vfs_getattr(). The main difference is
186 * that it uses a filename and base directory to determine the file location.
187 * Additionally, the use of AT_SYMLINK_NOFOLLOW in flags will prevent a symlink
188 * at the given name from being referenced.
189 *
190 * 0 will be returned on success, and a -ve error code if unsuccessful.
191 */
192int vfs_statx(int dfd, const char __user *filename, int flags,
193 struct kstat *stat, u32 request_mask)
194{
195 struct path path;
196 int error = -EINVAL;
197 unsigned lookup_flags;
198
199 if (vfs_stat_set_lookup_flags(&lookup_flags, flags))
200 return -EINVAL;
201retry:
202 error = user_path_at(dfd, filename, lookup_flags, &path);
203 if (error)
204 goto out;
205
206 error = vfs_getattr(&path, stat, request_mask, flags);
207 stat->mnt_id = real_mount(path.mnt)->mnt_id;
208 stat->result_mask |= STATX_MNT_ID;
209 if (path.mnt->mnt_root == path.dentry)
210 stat->attributes |= STATX_ATTR_MOUNT_ROOT;
211 stat->attributes_mask |= STATX_ATTR_MOUNT_ROOT;
212 path_put(&path);
213 if (retry_estale(error, lookup_flags)) {
214 lookup_flags |= LOOKUP_REVAL;
215 goto retry;
216 }
217out:
218 return error;
219}
220EXPORT_SYMBOL(vfs_statx);
221
222
223#ifdef __ARCH_WANT_OLD_STAT
224
225/*
226 * For backward compatibility? Maybe this should be moved
227 * into arch/i386 instead?
228 */
229static int cp_old_stat(struct kstat *stat, struct __old_kernel_stat __user * statbuf)
230{
231 static int warncount = 5;
232 struct __old_kernel_stat tmp;
233
234 if (warncount > 0) {
235 warncount--;
236 printk(KERN_WARNING "VFS: Warning: %s using old stat() call. Recompile your binary.\n",
237 current->comm);
238 } else if (warncount < 0) {
239 /* it's laughable, but... */
240 warncount = 0;
241 }
242
243 memset(&tmp, 0, sizeof(struct __old_kernel_stat));
244 tmp.st_dev = old_encode_dev(stat->dev);
245 tmp.st_ino = stat->ino;
246 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
247 return -EOVERFLOW;
248 tmp.st_mode = stat->mode;
249 tmp.st_nlink = stat->nlink;
250 if (tmp.st_nlink != stat->nlink)
251 return -EOVERFLOW;
252 SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
253 SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
254 tmp.st_rdev = old_encode_dev(stat->rdev);
255#if BITS_PER_LONG == 32
256 if (stat->size > MAX_NON_LFS)
257 return -EOVERFLOW;
258#endif
259 tmp.st_size = stat->size;
260 tmp.st_atime = stat->atime.tv_sec;
261 tmp.st_mtime = stat->mtime.tv_sec;
262 tmp.st_ctime = stat->ctime.tv_sec;
263 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
264}
265
266SYSCALL_DEFINE2(stat, const char __user *, filename,
267 struct __old_kernel_stat __user *, statbuf)
268{
269 struct kstat stat;
270 int error;
271
272 error = vfs_stat(filename, &stat);
273 if (error)
274 return error;
275
276 return cp_old_stat(&stat, statbuf);
277}
278
279SYSCALL_DEFINE2(lstat, const char __user *, filename,
280 struct __old_kernel_stat __user *, statbuf)
281{
282 struct kstat stat;
283 int error;
284
285 error = vfs_lstat(filename, &stat);
286 if (error)
287 return error;
288
289 return cp_old_stat(&stat, statbuf);
290}
291
292SYSCALL_DEFINE2(fstat, unsigned int, fd, struct __old_kernel_stat __user *, statbuf)
293{
294 struct kstat stat;
295 int error = vfs_fstat(fd, &stat);
296
297 if (!error)
298 error = cp_old_stat(&stat, statbuf);
299
300 return error;
301}
302
303#endif /* __ARCH_WANT_OLD_STAT */
304
305#ifdef __ARCH_WANT_NEW_STAT
306
307#if BITS_PER_LONG == 32
308# define choose_32_64(a,b) a
309#else
310# define choose_32_64(a,b) b
311#endif
312
313#define valid_dev(x) choose_32_64(old_valid_dev(x),true)
314#define encode_dev(x) choose_32_64(old_encode_dev,new_encode_dev)(x)
315
316#ifndef INIT_STRUCT_STAT_PADDING
317# define INIT_STRUCT_STAT_PADDING(st) memset(&st, 0, sizeof(st))
318#endif
319
320static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf)
321{
322 struct stat tmp;
323
324 if (!valid_dev(stat->dev) || !valid_dev(stat->rdev))
325 return -EOVERFLOW;
326#if BITS_PER_LONG == 32
327 if (stat->size > MAX_NON_LFS)
328 return -EOVERFLOW;
329#endif
330
331 INIT_STRUCT_STAT_PADDING(tmp);
332 tmp.st_dev = encode_dev(stat->dev);
333 tmp.st_ino = stat->ino;
334 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
335 return -EOVERFLOW;
336 tmp.st_mode = stat->mode;
337 tmp.st_nlink = stat->nlink;
338 if (tmp.st_nlink != stat->nlink)
339 return -EOVERFLOW;
340 SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
341 SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
342 tmp.st_rdev = encode_dev(stat->rdev);
343 tmp.st_size = stat->size;
344 tmp.st_atime = stat->atime.tv_sec;
345 tmp.st_mtime = stat->mtime.tv_sec;
346 tmp.st_ctime = stat->ctime.tv_sec;
347#ifdef STAT_HAVE_NSEC
348 tmp.st_atime_nsec = stat->atime.tv_nsec;
349 tmp.st_mtime_nsec = stat->mtime.tv_nsec;
350 tmp.st_ctime_nsec = stat->ctime.tv_nsec;
351#endif
352 tmp.st_blocks = stat->blocks;
353 tmp.st_blksize = stat->blksize;
354 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
355}
356
357SYSCALL_DEFINE2(newstat, const char __user *, filename,
358 struct stat __user *, statbuf)
359{
360 struct kstat stat;
361 int error = vfs_stat(filename, &stat);
362
363 if (error)
364 return error;
365 return cp_new_stat(&stat, statbuf);
366}
367
368SYSCALL_DEFINE2(newlstat, const char __user *, filename,
369 struct stat __user *, statbuf)
370{
371 struct kstat stat;
372 int error;
373
374 error = vfs_lstat(filename, &stat);
375 if (error)
376 return error;
377
378 return cp_new_stat(&stat, statbuf);
379}
380
381#if !defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_SYS_NEWFSTATAT)
382SYSCALL_DEFINE4(newfstatat, int, dfd, const char __user *, filename,
383 struct stat __user *, statbuf, int, flag)
384{
385 struct kstat stat;
386 int error;
387
388 error = vfs_fstatat(dfd, filename, &stat, flag);
389 if (error)
390 return error;
391 return cp_new_stat(&stat, statbuf);
392}
393#endif
394
395SYSCALL_DEFINE2(newfstat, unsigned int, fd, struct stat __user *, statbuf)
396{
397 struct kstat stat;
398 int error = vfs_fstat(fd, &stat);
399
400 if (!error)
401 error = cp_new_stat(&stat, statbuf);
402
403 return error;
404}
405#endif
406
407static int do_readlinkat(int dfd, const char __user *pathname,
408 char __user *buf, int bufsiz)
409{
410 struct path path;
411 int error;
412 int empty = 0;
413 unsigned int lookup_flags = LOOKUP_EMPTY;
414
415 if (bufsiz <= 0)
416 return -EINVAL;
417
418retry:
419 error = user_path_at_empty(dfd, pathname, lookup_flags, &path, &empty);
420 if (!error) {
421 struct inode *inode = d_backing_inode(path.dentry);
422
423 error = empty ? -ENOENT : -EINVAL;
424 /*
425 * AFS mountpoints allow readlink(2) but are not symlinks
426 */
427 if (d_is_symlink(path.dentry) || inode->i_op->readlink) {
428 error = security_inode_readlink(path.dentry);
429 if (!error) {
430 touch_atime(&path);
431 error = vfs_readlink(path.dentry, buf, bufsiz);
432 }
433 }
434 path_put(&path);
435 if (retry_estale(error, lookup_flags)) {
436 lookup_flags |= LOOKUP_REVAL;
437 goto retry;
438 }
439 }
440 return error;
441}
442
443SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname,
444 char __user *, buf, int, bufsiz)
445{
446 return do_readlinkat(dfd, pathname, buf, bufsiz);
447}
448
449SYSCALL_DEFINE3(readlink, const char __user *, path, char __user *, buf,
450 int, bufsiz)
451{
452 return do_readlinkat(AT_FDCWD, path, buf, bufsiz);
453}
454
455
456/* ---------- LFS-64 ----------- */
457#if defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_COMPAT_STAT64)
458
459#ifndef INIT_STRUCT_STAT64_PADDING
460# define INIT_STRUCT_STAT64_PADDING(st) memset(&st, 0, sizeof(st))
461#endif
462
463static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf)
464{
465 struct stat64 tmp;
466
467 INIT_STRUCT_STAT64_PADDING(tmp);
468#ifdef CONFIG_MIPS
469 /* mips has weird padding, so we don't get 64 bits there */
470 tmp.st_dev = new_encode_dev(stat->dev);
471 tmp.st_rdev = new_encode_dev(stat->rdev);
472#else
473 tmp.st_dev = huge_encode_dev(stat->dev);
474 tmp.st_rdev = huge_encode_dev(stat->rdev);
475#endif
476 tmp.st_ino = stat->ino;
477 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
478 return -EOVERFLOW;
479#ifdef STAT64_HAS_BROKEN_ST_INO
480 tmp.__st_ino = stat->ino;
481#endif
482 tmp.st_mode = stat->mode;
483 tmp.st_nlink = stat->nlink;
484 tmp.st_uid = from_kuid_munged(current_user_ns(), stat->uid);
485 tmp.st_gid = from_kgid_munged(current_user_ns(), stat->gid);
486 tmp.st_atime = stat->atime.tv_sec;
487 tmp.st_atime_nsec = stat->atime.tv_nsec;
488 tmp.st_mtime = stat->mtime.tv_sec;
489 tmp.st_mtime_nsec = stat->mtime.tv_nsec;
490 tmp.st_ctime = stat->ctime.tv_sec;
491 tmp.st_ctime_nsec = stat->ctime.tv_nsec;
492 tmp.st_size = stat->size;
493 tmp.st_blocks = stat->blocks;
494 tmp.st_blksize = stat->blksize;
495 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
496}
497
498SYSCALL_DEFINE2(stat64, const char __user *, filename,
499 struct stat64 __user *, statbuf)
500{
501 struct kstat stat;
502 int error = vfs_stat(filename, &stat);
503
504 if (!error)
505 error = cp_new_stat64(&stat, statbuf);
506
507 return error;
508}
509
510SYSCALL_DEFINE2(lstat64, const char __user *, filename,
511 struct stat64 __user *, statbuf)
512{
513 struct kstat stat;
514 int error = vfs_lstat(filename, &stat);
515
516 if (!error)
517 error = cp_new_stat64(&stat, statbuf);
518
519 return error;
520}
521
522SYSCALL_DEFINE2(fstat64, unsigned long, fd, struct stat64 __user *, statbuf)
523{
524 struct kstat stat;
525 int error = vfs_fstat(fd, &stat);
526
527 if (!error)
528 error = cp_new_stat64(&stat, statbuf);
529
530 return error;
531}
532
533SYSCALL_DEFINE4(fstatat64, int, dfd, const char __user *, filename,
534 struct stat64 __user *, statbuf, int, flag)
535{
536 struct kstat stat;
537 int error;
538
539 error = vfs_fstatat(dfd, filename, &stat, flag);
540 if (error)
541 return error;
542 return cp_new_stat64(&stat, statbuf);
543}
544#endif /* __ARCH_WANT_STAT64 || __ARCH_WANT_COMPAT_STAT64 */
545
546static noinline_for_stack int
547cp_statx(const struct kstat *stat, struct statx __user *buffer)
548{
549 struct statx tmp;
550
551 memset(&tmp, 0, sizeof(tmp));
552
553 tmp.stx_mask = stat->result_mask;
554 tmp.stx_blksize = stat->blksize;
555 tmp.stx_attributes = stat->attributes;
556 tmp.stx_nlink = stat->nlink;
557 tmp.stx_uid = from_kuid_munged(current_user_ns(), stat->uid);
558 tmp.stx_gid = from_kgid_munged(current_user_ns(), stat->gid);
559 tmp.stx_mode = stat->mode;
560 tmp.stx_ino = stat->ino;
561 tmp.stx_size = stat->size;
562 tmp.stx_blocks = stat->blocks;
563 tmp.stx_attributes_mask = stat->attributes_mask;
564 tmp.stx_atime.tv_sec = stat->atime.tv_sec;
565 tmp.stx_atime.tv_nsec = stat->atime.tv_nsec;
566 tmp.stx_btime.tv_sec = stat->btime.tv_sec;
567 tmp.stx_btime.tv_nsec = stat->btime.tv_nsec;
568 tmp.stx_ctime.tv_sec = stat->ctime.tv_sec;
569 tmp.stx_ctime.tv_nsec = stat->ctime.tv_nsec;
570 tmp.stx_mtime.tv_sec = stat->mtime.tv_sec;
571 tmp.stx_mtime.tv_nsec = stat->mtime.tv_nsec;
572 tmp.stx_rdev_major = MAJOR(stat->rdev);
573 tmp.stx_rdev_minor = MINOR(stat->rdev);
574 tmp.stx_dev_major = MAJOR(stat->dev);
575 tmp.stx_dev_minor = MINOR(stat->dev);
576 tmp.stx_mnt_id = stat->mnt_id;
577
578 return copy_to_user(buffer, &tmp, sizeof(tmp)) ? -EFAULT : 0;
579}
580
581int do_statx(int dfd, const char __user *filename, unsigned flags,
582 unsigned int mask, struct statx __user *buffer)
583{
584 struct kstat stat;
585 int error;
586
587 if (mask & STATX__RESERVED)
588 return -EINVAL;
589 if ((flags & AT_STATX_SYNC_TYPE) == AT_STATX_SYNC_TYPE)
590 return -EINVAL;
591
592 error = vfs_statx(dfd, filename, flags, &stat, mask);
593 if (error)
594 return error;
595
596 return cp_statx(&stat, buffer);
597}
598
599/**
600 * sys_statx - System call to get enhanced stats
601 * @dfd: Base directory to pathwalk from *or* fd to stat.
602 * @filename: File to stat or "" with AT_EMPTY_PATH
603 * @flags: AT_* flags to control pathwalk.
604 * @mask: Parts of statx struct actually required.
605 * @buffer: Result buffer.
606 *
607 * Note that fstat() can be emulated by setting dfd to the fd of interest,
608 * supplying "" as the filename and setting AT_EMPTY_PATH in the flags.
609 */
610SYSCALL_DEFINE5(statx,
611 int, dfd, const char __user *, filename, unsigned, flags,
612 unsigned int, mask,
613 struct statx __user *, buffer)
614{
615 return do_statx(dfd, filename, flags, mask, buffer);
616}
617
618#ifdef CONFIG_COMPAT
619static int cp_compat_stat(struct kstat *stat, struct compat_stat __user *ubuf)
620{
621 struct compat_stat tmp;
622
623 if (!old_valid_dev(stat->dev) || !old_valid_dev(stat->rdev))
624 return -EOVERFLOW;
625
626 memset(&tmp, 0, sizeof(tmp));
627 tmp.st_dev = old_encode_dev(stat->dev);
628 tmp.st_ino = stat->ino;
629 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
630 return -EOVERFLOW;
631 tmp.st_mode = stat->mode;
632 tmp.st_nlink = stat->nlink;
633 if (tmp.st_nlink != stat->nlink)
634 return -EOVERFLOW;
635 SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
636 SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
637 tmp.st_rdev = old_encode_dev(stat->rdev);
638 if ((u64) stat->size > MAX_NON_LFS)
639 return -EOVERFLOW;
640 tmp.st_size = stat->size;
641 tmp.st_atime = stat->atime.tv_sec;
642 tmp.st_atime_nsec = stat->atime.tv_nsec;
643 tmp.st_mtime = stat->mtime.tv_sec;
644 tmp.st_mtime_nsec = stat->mtime.tv_nsec;
645 tmp.st_ctime = stat->ctime.tv_sec;
646 tmp.st_ctime_nsec = stat->ctime.tv_nsec;
647 tmp.st_blocks = stat->blocks;
648 tmp.st_blksize = stat->blksize;
649 return copy_to_user(ubuf, &tmp, sizeof(tmp)) ? -EFAULT : 0;
650}
651
652COMPAT_SYSCALL_DEFINE2(newstat, const char __user *, filename,
653 struct compat_stat __user *, statbuf)
654{
655 struct kstat stat;
656 int error;
657
658 error = vfs_stat(filename, &stat);
659 if (error)
660 return error;
661 return cp_compat_stat(&stat, statbuf);
662}
663
664COMPAT_SYSCALL_DEFINE2(newlstat, const char __user *, filename,
665 struct compat_stat __user *, statbuf)
666{
667 struct kstat stat;
668 int error;
669
670 error = vfs_lstat(filename, &stat);
671 if (error)
672 return error;
673 return cp_compat_stat(&stat, statbuf);
674}
675
676#ifndef __ARCH_WANT_STAT64
677COMPAT_SYSCALL_DEFINE4(newfstatat, unsigned int, dfd,
678 const char __user *, filename,
679 struct compat_stat __user *, statbuf, int, flag)
680{
681 struct kstat stat;
682 int error;
683
684 error = vfs_fstatat(dfd, filename, &stat, flag);
685 if (error)
686 return error;
687 return cp_compat_stat(&stat, statbuf);
688}
689#endif
690
691COMPAT_SYSCALL_DEFINE2(newfstat, unsigned int, fd,
692 struct compat_stat __user *, statbuf)
693{
694 struct kstat stat;
695 int error = vfs_fstat(fd, &stat);
696
697 if (!error)
698 error = cp_compat_stat(&stat, statbuf);
699 return error;
700}
701#endif
702
703/* Caller is here responsible for sufficient locking (ie. inode->i_lock) */
704void __inode_add_bytes(struct inode *inode, loff_t bytes)
705{
706 inode->i_blocks += bytes >> 9;
707 bytes &= 511;
708 inode->i_bytes += bytes;
709 if (inode->i_bytes >= 512) {
710 inode->i_blocks++;
711 inode->i_bytes -= 512;
712 }
713}
714EXPORT_SYMBOL(__inode_add_bytes);
715
716void inode_add_bytes(struct inode *inode, loff_t bytes)
717{
718 spin_lock(&inode->i_lock);
719 __inode_add_bytes(inode, bytes);
720 spin_unlock(&inode->i_lock);
721}
722
723EXPORT_SYMBOL(inode_add_bytes);
724
725void __inode_sub_bytes(struct inode *inode, loff_t bytes)
726{
727 inode->i_blocks -= bytes >> 9;
728 bytes &= 511;
729 if (inode->i_bytes < bytes) {
730 inode->i_blocks--;
731 inode->i_bytes += 512;
732 }
733 inode->i_bytes -= bytes;
734}
735
736EXPORT_SYMBOL(__inode_sub_bytes);
737
738void inode_sub_bytes(struct inode *inode, loff_t bytes)
739{
740 spin_lock(&inode->i_lock);
741 __inode_sub_bytes(inode, bytes);
742 spin_unlock(&inode->i_lock);
743}
744
745EXPORT_SYMBOL(inode_sub_bytes);
746
747loff_t inode_get_bytes(struct inode *inode)
748{
749 loff_t ret;
750
751 spin_lock(&inode->i_lock);
752 ret = __inode_get_bytes(inode);
753 spin_unlock(&inode->i_lock);
754 return ret;
755}
756
757EXPORT_SYMBOL(inode_get_bytes);
758
759void inode_set_bytes(struct inode *inode, loff_t bytes)
760{
761 /* Caller is here responsible for sufficient locking
762 * (ie. inode->i_lock) */
763 inode->i_blocks = bytes >> 9;
764 inode->i_bytes = bytes & 511;
765}
766
767EXPORT_SYMBOL(inode_set_bytes);
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->size = i_size_read(inode);
31 stat->atime = inode->i_atime;
32 stat->mtime = inode->i_mtime;
33 stat->ctime = inode->i_ctime;
34 stat->blksize = (1 << inode->i_blkbits);
35 stat->blocks = inode->i_blocks;
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 |
79 AT_EMPTY_PATH)) != 0)
80 goto out;
81
82 if (!(flag & AT_SYMLINK_NOFOLLOW))
83 lookup_flags |= LOOKUP_FOLLOW;
84 if (flag & AT_EMPTY_PATH)
85 lookup_flags |= LOOKUP_EMPTY;
86
87 error = user_path_at(dfd, filename, lookup_flags, &path);
88 if (error)
89 goto out;
90
91 error = vfs_getattr(path.mnt, path.dentry, stat);
92 path_put(&path);
93out:
94 return error;
95}
96EXPORT_SYMBOL(vfs_fstatat);
97
98int vfs_stat(const char __user *name, struct kstat *stat)
99{
100 return vfs_fstatat(AT_FDCWD, name, stat, 0);
101}
102EXPORT_SYMBOL(vfs_stat);
103
104int vfs_lstat(const char __user *name, struct kstat *stat)
105{
106 return vfs_fstatat(AT_FDCWD, name, stat, AT_SYMLINK_NOFOLLOW);
107}
108EXPORT_SYMBOL(vfs_lstat);
109
110
111#ifdef __ARCH_WANT_OLD_STAT
112
113/*
114 * For backward compatibility? Maybe this should be moved
115 * into arch/i386 instead?
116 */
117static int cp_old_stat(struct kstat *stat, struct __old_kernel_stat __user * statbuf)
118{
119 static int warncount = 5;
120 struct __old_kernel_stat tmp;
121
122 if (warncount > 0) {
123 warncount--;
124 printk(KERN_WARNING "VFS: Warning: %s using old stat() call. Recompile your binary.\n",
125 current->comm);
126 } else if (warncount < 0) {
127 /* it's laughable, but... */
128 warncount = 0;
129 }
130
131 memset(&tmp, 0, sizeof(struct __old_kernel_stat));
132 tmp.st_dev = old_encode_dev(stat->dev);
133 tmp.st_ino = stat->ino;
134 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
135 return -EOVERFLOW;
136 tmp.st_mode = stat->mode;
137 tmp.st_nlink = stat->nlink;
138 if (tmp.st_nlink != stat->nlink)
139 return -EOVERFLOW;
140 SET_UID(tmp.st_uid, stat->uid);
141 SET_GID(tmp.st_gid, stat->gid);
142 tmp.st_rdev = old_encode_dev(stat->rdev);
143#if BITS_PER_LONG == 32
144 if (stat->size > MAX_NON_LFS)
145 return -EOVERFLOW;
146#endif
147 tmp.st_size = stat->size;
148 tmp.st_atime = stat->atime.tv_sec;
149 tmp.st_mtime = stat->mtime.tv_sec;
150 tmp.st_ctime = stat->ctime.tv_sec;
151 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
152}
153
154SYSCALL_DEFINE2(stat, const char __user *, filename,
155 struct __old_kernel_stat __user *, statbuf)
156{
157 struct kstat stat;
158 int error;
159
160 error = vfs_stat(filename, &stat);
161 if (error)
162 return error;
163
164 return cp_old_stat(&stat, statbuf);
165}
166
167SYSCALL_DEFINE2(lstat, const char __user *, filename,
168 struct __old_kernel_stat __user *, statbuf)
169{
170 struct kstat stat;
171 int error;
172
173 error = vfs_lstat(filename, &stat);
174 if (error)
175 return error;
176
177 return cp_old_stat(&stat, statbuf);
178}
179
180SYSCALL_DEFINE2(fstat, unsigned int, fd, struct __old_kernel_stat __user *, statbuf)
181{
182 struct kstat stat;
183 int error = vfs_fstat(fd, &stat);
184
185 if (!error)
186 error = cp_old_stat(&stat, statbuf);
187
188 return error;
189}
190
191#endif /* __ARCH_WANT_OLD_STAT */
192
193static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf)
194{
195 struct stat tmp;
196
197#if BITS_PER_LONG == 32
198 if (!old_valid_dev(stat->dev) || !old_valid_dev(stat->rdev))
199 return -EOVERFLOW;
200#else
201 if (!new_valid_dev(stat->dev) || !new_valid_dev(stat->rdev))
202 return -EOVERFLOW;
203#endif
204
205 memset(&tmp, 0, sizeof(tmp));
206#if BITS_PER_LONG == 32
207 tmp.st_dev = old_encode_dev(stat->dev);
208#else
209 tmp.st_dev = new_encode_dev(stat->dev);
210#endif
211 tmp.st_ino = stat->ino;
212 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
213 return -EOVERFLOW;
214 tmp.st_mode = stat->mode;
215 tmp.st_nlink = stat->nlink;
216 if (tmp.st_nlink != stat->nlink)
217 return -EOVERFLOW;
218 SET_UID(tmp.st_uid, stat->uid);
219 SET_GID(tmp.st_gid, stat->gid);
220#if BITS_PER_LONG == 32
221 tmp.st_rdev = old_encode_dev(stat->rdev);
222#else
223 tmp.st_rdev = new_encode_dev(stat->rdev);
224#endif
225#if BITS_PER_LONG == 32
226 if (stat->size > MAX_NON_LFS)
227 return -EOVERFLOW;
228#endif
229 tmp.st_size = stat->size;
230 tmp.st_atime = stat->atime.tv_sec;
231 tmp.st_mtime = stat->mtime.tv_sec;
232 tmp.st_ctime = stat->ctime.tv_sec;
233#ifdef STAT_HAVE_NSEC
234 tmp.st_atime_nsec = stat->atime.tv_nsec;
235 tmp.st_mtime_nsec = stat->mtime.tv_nsec;
236 tmp.st_ctime_nsec = stat->ctime.tv_nsec;
237#endif
238 tmp.st_blocks = stat->blocks;
239 tmp.st_blksize = stat->blksize;
240 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
241}
242
243SYSCALL_DEFINE2(newstat, const char __user *, filename,
244 struct stat __user *, statbuf)
245{
246 struct kstat stat;
247 int error = vfs_stat(filename, &stat);
248
249 if (error)
250 return error;
251 return cp_new_stat(&stat, statbuf);
252}
253
254SYSCALL_DEFINE2(newlstat, const char __user *, filename,
255 struct stat __user *, statbuf)
256{
257 struct kstat stat;
258 int error;
259
260 error = vfs_lstat(filename, &stat);
261 if (error)
262 return error;
263
264 return cp_new_stat(&stat, statbuf);
265}
266
267#if !defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_SYS_NEWFSTATAT)
268SYSCALL_DEFINE4(newfstatat, int, dfd, const char __user *, filename,
269 struct stat __user *, statbuf, int, flag)
270{
271 struct kstat stat;
272 int error;
273
274 error = vfs_fstatat(dfd, filename, &stat, flag);
275 if (error)
276 return error;
277 return cp_new_stat(&stat, statbuf);
278}
279#endif
280
281SYSCALL_DEFINE2(newfstat, unsigned int, fd, struct stat __user *, statbuf)
282{
283 struct kstat stat;
284 int error = vfs_fstat(fd, &stat);
285
286 if (!error)
287 error = cp_new_stat(&stat, statbuf);
288
289 return error;
290}
291
292SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname,
293 char __user *, buf, int, bufsiz)
294{
295 struct path path;
296 int error;
297
298 if (bufsiz <= 0)
299 return -EINVAL;
300
301 error = user_path_at(dfd, pathname, LOOKUP_EMPTY, &path);
302 if (!error) {
303 struct inode *inode = path.dentry->d_inode;
304
305 error = -EINVAL;
306 if (inode->i_op->readlink) {
307 error = security_inode_readlink(path.dentry);
308 if (!error) {
309 touch_atime(path.mnt, path.dentry);
310 error = inode->i_op->readlink(path.dentry,
311 buf, bufsiz);
312 }
313 }
314 path_put(&path);
315 }
316 return error;
317}
318
319SYSCALL_DEFINE3(readlink, const char __user *, path, char __user *, buf,
320 int, bufsiz)
321{
322 return sys_readlinkat(AT_FDCWD, path, buf, bufsiz);
323}
324
325
326/* ---------- LFS-64 ----------- */
327#ifdef __ARCH_WANT_STAT64
328
329static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf)
330{
331 struct stat64 tmp;
332
333 memset(&tmp, 0, sizeof(struct stat64));
334#ifdef CONFIG_MIPS
335 /* mips has weird padding, so we don't get 64 bits there */
336 if (!new_valid_dev(stat->dev) || !new_valid_dev(stat->rdev))
337 return -EOVERFLOW;
338 tmp.st_dev = new_encode_dev(stat->dev);
339 tmp.st_rdev = new_encode_dev(stat->rdev);
340#else
341 tmp.st_dev = huge_encode_dev(stat->dev);
342 tmp.st_rdev = huge_encode_dev(stat->rdev);
343#endif
344 tmp.st_ino = stat->ino;
345 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
346 return -EOVERFLOW;
347#ifdef STAT64_HAS_BROKEN_ST_INO
348 tmp.__st_ino = stat->ino;
349#endif
350 tmp.st_mode = stat->mode;
351 tmp.st_nlink = stat->nlink;
352 tmp.st_uid = stat->uid;
353 tmp.st_gid = stat->gid;
354 tmp.st_atime = stat->atime.tv_sec;
355 tmp.st_atime_nsec = stat->atime.tv_nsec;
356 tmp.st_mtime = stat->mtime.tv_sec;
357 tmp.st_mtime_nsec = stat->mtime.tv_nsec;
358 tmp.st_ctime = stat->ctime.tv_sec;
359 tmp.st_ctime_nsec = stat->ctime.tv_nsec;
360 tmp.st_size = stat->size;
361 tmp.st_blocks = stat->blocks;
362 tmp.st_blksize = stat->blksize;
363 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
364}
365
366SYSCALL_DEFINE2(stat64, const char __user *, filename,
367 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}
377
378SYSCALL_DEFINE2(lstat64, const char __user *, filename,
379 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}
389
390SYSCALL_DEFINE2(fstat64, unsigned long, fd, struct stat64 __user *, statbuf)
391{
392 struct kstat stat;
393 int error = vfs_fstat(fd, &stat);
394
395 if (!error)
396 error = cp_new_stat64(&stat, statbuf);
397
398 return error;
399}
400
401SYSCALL_DEFINE4(fstatat64, int, dfd, const char __user *, filename,
402 struct stat64 __user *, statbuf, int, flag)
403{
404 struct kstat stat;
405 int error;
406
407 error = vfs_fstatat(dfd, filename, &stat, flag);
408 if (error)
409 return error;
410 return cp_new_stat64(&stat, statbuf);
411}
412#endif /* __ARCH_WANT_STAT64 */
413
414/* Caller is here responsible for sufficient locking (ie. inode->i_lock) */
415void __inode_add_bytes(struct inode *inode, loff_t bytes)
416{
417 inode->i_blocks += bytes >> 9;
418 bytes &= 511;
419 inode->i_bytes += bytes;
420 if (inode->i_bytes >= 512) {
421 inode->i_blocks++;
422 inode->i_bytes -= 512;
423 }
424}
425
426void inode_add_bytes(struct inode *inode, loff_t bytes)
427{
428 spin_lock(&inode->i_lock);
429 __inode_add_bytes(inode, bytes);
430 spin_unlock(&inode->i_lock);
431}
432
433EXPORT_SYMBOL(inode_add_bytes);
434
435void inode_sub_bytes(struct inode *inode, loff_t bytes)
436{
437 spin_lock(&inode->i_lock);
438 inode->i_blocks -= bytes >> 9;
439 bytes &= 511;
440 if (inode->i_bytes < bytes) {
441 inode->i_blocks--;
442 inode->i_bytes += 512;
443 }
444 inode->i_bytes -= bytes;
445 spin_unlock(&inode->i_lock);
446}
447
448EXPORT_SYMBOL(inode_sub_bytes);
449
450loff_t inode_get_bytes(struct inode *inode)
451{
452 loff_t ret;
453
454 spin_lock(&inode->i_lock);
455 ret = (((loff_t)inode->i_blocks) << 9) + inode->i_bytes;
456 spin_unlock(&inode->i_lock);
457 return ret;
458}
459
460EXPORT_SYMBOL(inode_get_bytes);
461
462void inode_set_bytes(struct inode *inode, loff_t bytes)
463{
464 /* Caller is here responsible for sufficient locking
465 * (ie. inode->i_lock) */
466 inode->i_blocks = bytes >> 9;
467 inode->i_bytes = bytes & 511;
468}
469
470EXPORT_SYMBOL(inode_set_bytes);