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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// 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/blkdev.h>
9#include <linux/export.h>
10#include <linux/mm.h>
11#include <linux/errno.h>
12#include <linux/file.h>
13#include <linux/highuid.h>
14#include <linux/fs.h>
15#include <linux/namei.h>
16#include <linux/security.h>
17#include <linux/cred.h>
18#include <linux/syscalls.h>
19#include <linux/pagemap.h>
20#include <linux/compat.h>
21#include <linux/iversion.h>
22
23#include <linux/uaccess.h>
24#include <asm/unistd.h>
25
26#include "internal.h"
27#include "mount.h"
28
29/**
30 * generic_fillattr - Fill in the basic attributes from the inode struct
31 * @idmap: idmap of the mount the inode was found from
32 * @request_mask: statx request_mask
33 * @inode: Inode to use as the source
34 * @stat: Where to fill in the attributes
35 *
36 * Fill in the basic attributes in the kstat structure from data that's to be
37 * found on the VFS inode structure. This is the default if no getattr inode
38 * operation is supplied.
39 *
40 * If the inode has been found through an idmapped mount the idmap of
41 * the vfsmount must be passed through @idmap. This function will then
42 * take care to map the inode according to @idmap before filling in the
43 * uid and gid filds. On non-idmapped mounts or if permission checking is to be
44 * performed on the raw inode simply pass @nop_mnt_idmap.
45 */
46void generic_fillattr(struct mnt_idmap *idmap, u32 request_mask,
47 struct inode *inode, struct kstat *stat)
48{
49 vfsuid_t vfsuid = i_uid_into_vfsuid(idmap, inode);
50 vfsgid_t vfsgid = i_gid_into_vfsgid(idmap, inode);
51
52 stat->dev = inode->i_sb->s_dev;
53 stat->ino = inode->i_ino;
54 stat->mode = inode->i_mode;
55 stat->nlink = inode->i_nlink;
56 stat->uid = vfsuid_into_kuid(vfsuid);
57 stat->gid = vfsgid_into_kgid(vfsgid);
58 stat->rdev = inode->i_rdev;
59 stat->size = i_size_read(inode);
60 stat->atime = inode_get_atime(inode);
61 stat->mtime = inode_get_mtime(inode);
62 stat->ctime = inode_get_ctime(inode);
63 stat->blksize = i_blocksize(inode);
64 stat->blocks = inode->i_blocks;
65
66 if ((request_mask & STATX_CHANGE_COOKIE) && IS_I_VERSION(inode)) {
67 stat->result_mask |= STATX_CHANGE_COOKIE;
68 stat->change_cookie = inode_query_iversion(inode);
69 }
70
71}
72EXPORT_SYMBOL(generic_fillattr);
73
74/**
75 * generic_fill_statx_attr - Fill in the statx attributes from the inode flags
76 * @inode: Inode to use as the source
77 * @stat: Where to fill in the attribute flags
78 *
79 * Fill in the STATX_ATTR_* flags in the kstat structure for properties of the
80 * inode that are published on i_flags and enforced by the VFS.
81 */
82void generic_fill_statx_attr(struct inode *inode, struct kstat *stat)
83{
84 if (inode->i_flags & S_IMMUTABLE)
85 stat->attributes |= STATX_ATTR_IMMUTABLE;
86 if (inode->i_flags & S_APPEND)
87 stat->attributes |= STATX_ATTR_APPEND;
88 stat->attributes_mask |= KSTAT_ATTR_VFS_FLAGS;
89}
90EXPORT_SYMBOL(generic_fill_statx_attr);
91
92/**
93 * vfs_getattr_nosec - getattr without security checks
94 * @path: file to get attributes from
95 * @stat: structure to return attributes in
96 * @request_mask: STATX_xxx flags indicating what the caller wants
97 * @query_flags: Query mode (AT_STATX_SYNC_TYPE)
98 *
99 * Get attributes without calling security_inode_getattr.
100 *
101 * Currently the only caller other than vfs_getattr is internal to the
102 * filehandle lookup code, which uses only the inode number and returns no
103 * attributes to any user. Any other code probably wants vfs_getattr.
104 */
105int vfs_getattr_nosec(const struct path *path, struct kstat *stat,
106 u32 request_mask, unsigned int query_flags)
107{
108 struct mnt_idmap *idmap;
109 struct inode *inode = d_backing_inode(path->dentry);
110
111 memset(stat, 0, sizeof(*stat));
112 stat->result_mask |= STATX_BASIC_STATS;
113 query_flags &= AT_STATX_SYNC_TYPE;
114
115 /* allow the fs to override these if it really wants to */
116 /* SB_NOATIME means filesystem supplies dummy atime value */
117 if (inode->i_sb->s_flags & SB_NOATIME)
118 stat->result_mask &= ~STATX_ATIME;
119
120 /*
121 * Note: If you add another clause to set an attribute flag, please
122 * update attributes_mask below.
123 */
124 if (IS_AUTOMOUNT(inode))
125 stat->attributes |= STATX_ATTR_AUTOMOUNT;
126
127 if (IS_DAX(inode))
128 stat->attributes |= STATX_ATTR_DAX;
129
130 stat->attributes_mask |= (STATX_ATTR_AUTOMOUNT |
131 STATX_ATTR_DAX);
132
133 idmap = mnt_idmap(path->mnt);
134 if (inode->i_op->getattr)
135 return inode->i_op->getattr(idmap, path, stat,
136 request_mask,
137 query_flags | AT_GETATTR_NOSEC);
138
139 generic_fillattr(idmap, request_mask, inode, stat);
140 return 0;
141}
142EXPORT_SYMBOL(vfs_getattr_nosec);
143
144/*
145 * vfs_getattr - Get the enhanced basic attributes of a file
146 * @path: The file of interest
147 * @stat: Where to return the statistics
148 * @request_mask: STATX_xxx flags indicating what the caller wants
149 * @query_flags: Query mode (AT_STATX_SYNC_TYPE)
150 *
151 * Ask the filesystem for a file's attributes. The caller must indicate in
152 * request_mask and query_flags to indicate what they want.
153 *
154 * If the file is remote, the filesystem can be forced to update the attributes
155 * from the backing store by passing AT_STATX_FORCE_SYNC in query_flags or can
156 * suppress the update by passing AT_STATX_DONT_SYNC.
157 *
158 * Bits must have been set in request_mask to indicate which attributes the
159 * caller wants retrieving. Any such attribute not requested may be returned
160 * anyway, but the value may be approximate, and, if remote, may not have been
161 * synchronised with the server.
162 *
163 * 0 will be returned on success, and a -ve error code if unsuccessful.
164 */
165int vfs_getattr(const struct path *path, struct kstat *stat,
166 u32 request_mask, unsigned int query_flags)
167{
168 int retval;
169
170 if (WARN_ON_ONCE(query_flags & AT_GETATTR_NOSEC))
171 return -EPERM;
172
173 retval = security_inode_getattr(path);
174 if (retval)
175 return retval;
176 return vfs_getattr_nosec(path, stat, request_mask, query_flags);
177}
178EXPORT_SYMBOL(vfs_getattr);
179
180/**
181 * vfs_fstat - Get the basic attributes by file descriptor
182 * @fd: The file descriptor referring to the file of interest
183 * @stat: The result structure to fill in.
184 *
185 * This function is a wrapper around vfs_getattr(). The main difference is
186 * that it uses a file descriptor to determine the file location.
187 *
188 * 0 will be returned on success, and a -ve error code if unsuccessful.
189 */
190int vfs_fstat(int fd, struct kstat *stat)
191{
192 struct fd f;
193 int error;
194
195 f = fdget_raw(fd);
196 if (!f.file)
197 return -EBADF;
198 error = vfs_getattr(&f.file->f_path, stat, STATX_BASIC_STATS, 0);
199 fdput(f);
200 return error;
201}
202
203int getname_statx_lookup_flags(int flags)
204{
205 int lookup_flags = 0;
206
207 if (!(flags & AT_SYMLINK_NOFOLLOW))
208 lookup_flags |= LOOKUP_FOLLOW;
209 if (!(flags & AT_NO_AUTOMOUNT))
210 lookup_flags |= LOOKUP_AUTOMOUNT;
211 if (flags & AT_EMPTY_PATH)
212 lookup_flags |= LOOKUP_EMPTY;
213
214 return lookup_flags;
215}
216
217/**
218 * vfs_statx - Get basic and extra attributes by filename
219 * @dfd: A file descriptor representing the base dir for a relative filename
220 * @filename: The name of the file of interest
221 * @flags: Flags to control the query
222 * @stat: The result structure to fill in.
223 * @request_mask: STATX_xxx flags indicating what the caller wants
224 *
225 * This function is a wrapper around vfs_getattr(). The main difference is
226 * that it uses a filename and base directory to determine the file location.
227 * Additionally, the use of AT_SYMLINK_NOFOLLOW in flags will prevent a symlink
228 * at the given name from being referenced.
229 *
230 * 0 will be returned on success, and a -ve error code if unsuccessful.
231 */
232static int vfs_statx(int dfd, struct filename *filename, int flags,
233 struct kstat *stat, u32 request_mask)
234{
235 struct path path;
236 unsigned int lookup_flags = getname_statx_lookup_flags(flags);
237 int error;
238
239 if (flags & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT | AT_EMPTY_PATH |
240 AT_STATX_SYNC_TYPE))
241 return -EINVAL;
242
243retry:
244 error = filename_lookup(dfd, filename, lookup_flags, &path, NULL);
245 if (error)
246 goto out;
247
248 error = vfs_getattr(&path, stat, request_mask, flags);
249
250 if (request_mask & STATX_MNT_ID_UNIQUE) {
251 stat->mnt_id = real_mount(path.mnt)->mnt_id_unique;
252 stat->result_mask |= STATX_MNT_ID_UNIQUE;
253 } else {
254 stat->mnt_id = real_mount(path.mnt)->mnt_id;
255 stat->result_mask |= STATX_MNT_ID;
256 }
257
258 if (path.mnt->mnt_root == path.dentry)
259 stat->attributes |= STATX_ATTR_MOUNT_ROOT;
260 stat->attributes_mask |= STATX_ATTR_MOUNT_ROOT;
261
262 /* Handle STATX_DIOALIGN for block devices. */
263 if (request_mask & STATX_DIOALIGN) {
264 struct inode *inode = d_backing_inode(path.dentry);
265
266 if (S_ISBLK(inode->i_mode))
267 bdev_statx_dioalign(inode, stat);
268 }
269
270 path_put(&path);
271 if (retry_estale(error, lookup_flags)) {
272 lookup_flags |= LOOKUP_REVAL;
273 goto retry;
274 }
275out:
276 return error;
277}
278
279int vfs_fstatat(int dfd, const char __user *filename,
280 struct kstat *stat, int flags)
281{
282 int ret;
283 int statx_flags = flags | AT_NO_AUTOMOUNT;
284 struct filename *name;
285
286 /*
287 * Work around glibc turning fstat() into fstatat(AT_EMPTY_PATH)
288 *
289 * If AT_EMPTY_PATH is set, we expect the common case to be that
290 * empty path, and avoid doing all the extra pathname work.
291 */
292 if (dfd >= 0 && flags == AT_EMPTY_PATH) {
293 char c;
294
295 ret = get_user(c, filename);
296 if (unlikely(ret))
297 return ret;
298
299 if (likely(!c))
300 return vfs_fstat(dfd, stat);
301 }
302
303 name = getname_flags(filename, getname_statx_lookup_flags(statx_flags), NULL);
304 ret = vfs_statx(dfd, name, statx_flags, stat, STATX_BASIC_STATS);
305 putname(name);
306
307 return ret;
308}
309
310#ifdef __ARCH_WANT_OLD_STAT
311
312/*
313 * For backward compatibility? Maybe this should be moved
314 * into arch/i386 instead?
315 */
316static int cp_old_stat(struct kstat *stat, struct __old_kernel_stat __user * statbuf)
317{
318 static int warncount = 5;
319 struct __old_kernel_stat tmp;
320
321 if (warncount > 0) {
322 warncount--;
323 printk(KERN_WARNING "VFS: Warning: %s using old stat() call. Recompile your binary.\n",
324 current->comm);
325 } else if (warncount < 0) {
326 /* it's laughable, but... */
327 warncount = 0;
328 }
329
330 memset(&tmp, 0, sizeof(struct __old_kernel_stat));
331 tmp.st_dev = old_encode_dev(stat->dev);
332 tmp.st_ino = stat->ino;
333 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
334 return -EOVERFLOW;
335 tmp.st_mode = stat->mode;
336 tmp.st_nlink = stat->nlink;
337 if (tmp.st_nlink != stat->nlink)
338 return -EOVERFLOW;
339 SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
340 SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
341 tmp.st_rdev = old_encode_dev(stat->rdev);
342#if BITS_PER_LONG == 32
343 if (stat->size > MAX_NON_LFS)
344 return -EOVERFLOW;
345#endif
346 tmp.st_size = stat->size;
347 tmp.st_atime = stat->atime.tv_sec;
348 tmp.st_mtime = stat->mtime.tv_sec;
349 tmp.st_ctime = stat->ctime.tv_sec;
350 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
351}
352
353SYSCALL_DEFINE2(stat, const char __user *, filename,
354 struct __old_kernel_stat __user *, statbuf)
355{
356 struct kstat stat;
357 int error;
358
359 error = vfs_stat(filename, &stat);
360 if (error)
361 return error;
362
363 return cp_old_stat(&stat, statbuf);
364}
365
366SYSCALL_DEFINE2(lstat, const char __user *, filename,
367 struct __old_kernel_stat __user *, statbuf)
368{
369 struct kstat stat;
370 int error;
371
372 error = vfs_lstat(filename, &stat);
373 if (error)
374 return error;
375
376 return cp_old_stat(&stat, statbuf);
377}
378
379SYSCALL_DEFINE2(fstat, unsigned int, fd, struct __old_kernel_stat __user *, statbuf)
380{
381 struct kstat stat;
382 int error = vfs_fstat(fd, &stat);
383
384 if (!error)
385 error = cp_old_stat(&stat, statbuf);
386
387 return error;
388}
389
390#endif /* __ARCH_WANT_OLD_STAT */
391
392#ifdef __ARCH_WANT_NEW_STAT
393
394#ifndef INIT_STRUCT_STAT_PADDING
395# define INIT_STRUCT_STAT_PADDING(st) memset(&st, 0, sizeof(st))
396#endif
397
398static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf)
399{
400 struct stat tmp;
401
402 if (sizeof(tmp.st_dev) < 4 && !old_valid_dev(stat->dev))
403 return -EOVERFLOW;
404 if (sizeof(tmp.st_rdev) < 4 && !old_valid_dev(stat->rdev))
405 return -EOVERFLOW;
406#if BITS_PER_LONG == 32
407 if (stat->size > MAX_NON_LFS)
408 return -EOVERFLOW;
409#endif
410
411 INIT_STRUCT_STAT_PADDING(tmp);
412 tmp.st_dev = new_encode_dev(stat->dev);
413 tmp.st_ino = stat->ino;
414 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
415 return -EOVERFLOW;
416 tmp.st_mode = stat->mode;
417 tmp.st_nlink = stat->nlink;
418 if (tmp.st_nlink != stat->nlink)
419 return -EOVERFLOW;
420 SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
421 SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
422 tmp.st_rdev = new_encode_dev(stat->rdev);
423 tmp.st_size = stat->size;
424 tmp.st_atime = stat->atime.tv_sec;
425 tmp.st_mtime = stat->mtime.tv_sec;
426 tmp.st_ctime = stat->ctime.tv_sec;
427#ifdef STAT_HAVE_NSEC
428 tmp.st_atime_nsec = stat->atime.tv_nsec;
429 tmp.st_mtime_nsec = stat->mtime.tv_nsec;
430 tmp.st_ctime_nsec = stat->ctime.tv_nsec;
431#endif
432 tmp.st_blocks = stat->blocks;
433 tmp.st_blksize = stat->blksize;
434 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
435}
436
437SYSCALL_DEFINE2(newstat, const char __user *, filename,
438 struct stat __user *, statbuf)
439{
440 struct kstat stat;
441 int error = vfs_stat(filename, &stat);
442
443 if (error)
444 return error;
445 return cp_new_stat(&stat, statbuf);
446}
447
448SYSCALL_DEFINE2(newlstat, const char __user *, filename,
449 struct stat __user *, statbuf)
450{
451 struct kstat stat;
452 int error;
453
454 error = vfs_lstat(filename, &stat);
455 if (error)
456 return error;
457
458 return cp_new_stat(&stat, statbuf);
459}
460
461#if !defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_SYS_NEWFSTATAT)
462SYSCALL_DEFINE4(newfstatat, int, dfd, const char __user *, filename,
463 struct stat __user *, statbuf, int, flag)
464{
465 struct kstat stat;
466 int error;
467
468 error = vfs_fstatat(dfd, filename, &stat, flag);
469 if (error)
470 return error;
471 return cp_new_stat(&stat, statbuf);
472}
473#endif
474
475SYSCALL_DEFINE2(newfstat, unsigned int, fd, struct stat __user *, statbuf)
476{
477 struct kstat stat;
478 int error = vfs_fstat(fd, &stat);
479
480 if (!error)
481 error = cp_new_stat(&stat, statbuf);
482
483 return error;
484}
485#endif
486
487static int do_readlinkat(int dfd, const char __user *pathname,
488 char __user *buf, int bufsiz)
489{
490 struct path path;
491 int error;
492 int empty = 0;
493 unsigned int lookup_flags = LOOKUP_EMPTY;
494
495 if (bufsiz <= 0)
496 return -EINVAL;
497
498retry:
499 error = user_path_at_empty(dfd, pathname, lookup_flags, &path, &empty);
500 if (!error) {
501 struct inode *inode = d_backing_inode(path.dentry);
502
503 error = empty ? -ENOENT : -EINVAL;
504 /*
505 * AFS mountpoints allow readlink(2) but are not symlinks
506 */
507 if (d_is_symlink(path.dentry) || inode->i_op->readlink) {
508 error = security_inode_readlink(path.dentry);
509 if (!error) {
510 touch_atime(&path);
511 error = vfs_readlink(path.dentry, buf, bufsiz);
512 }
513 }
514 path_put(&path);
515 if (retry_estale(error, lookup_flags)) {
516 lookup_flags |= LOOKUP_REVAL;
517 goto retry;
518 }
519 }
520 return error;
521}
522
523SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname,
524 char __user *, buf, int, bufsiz)
525{
526 return do_readlinkat(dfd, pathname, buf, bufsiz);
527}
528
529SYSCALL_DEFINE3(readlink, const char __user *, path, char __user *, buf,
530 int, bufsiz)
531{
532 return do_readlinkat(AT_FDCWD, path, buf, bufsiz);
533}
534
535
536/* ---------- LFS-64 ----------- */
537#if defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_COMPAT_STAT64)
538
539#ifndef INIT_STRUCT_STAT64_PADDING
540# define INIT_STRUCT_STAT64_PADDING(st) memset(&st, 0, sizeof(st))
541#endif
542
543static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf)
544{
545 struct stat64 tmp;
546
547 INIT_STRUCT_STAT64_PADDING(tmp);
548#ifdef CONFIG_MIPS
549 /* mips has weird padding, so we don't get 64 bits there */
550 tmp.st_dev = new_encode_dev(stat->dev);
551 tmp.st_rdev = new_encode_dev(stat->rdev);
552#else
553 tmp.st_dev = huge_encode_dev(stat->dev);
554 tmp.st_rdev = huge_encode_dev(stat->rdev);
555#endif
556 tmp.st_ino = stat->ino;
557 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
558 return -EOVERFLOW;
559#ifdef STAT64_HAS_BROKEN_ST_INO
560 tmp.__st_ino = stat->ino;
561#endif
562 tmp.st_mode = stat->mode;
563 tmp.st_nlink = stat->nlink;
564 tmp.st_uid = from_kuid_munged(current_user_ns(), stat->uid);
565 tmp.st_gid = from_kgid_munged(current_user_ns(), stat->gid);
566 tmp.st_atime = stat->atime.tv_sec;
567 tmp.st_atime_nsec = stat->atime.tv_nsec;
568 tmp.st_mtime = stat->mtime.tv_sec;
569 tmp.st_mtime_nsec = stat->mtime.tv_nsec;
570 tmp.st_ctime = stat->ctime.tv_sec;
571 tmp.st_ctime_nsec = stat->ctime.tv_nsec;
572 tmp.st_size = stat->size;
573 tmp.st_blocks = stat->blocks;
574 tmp.st_blksize = stat->blksize;
575 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
576}
577
578SYSCALL_DEFINE2(stat64, const char __user *, filename,
579 struct stat64 __user *, statbuf)
580{
581 struct kstat stat;
582 int error = vfs_stat(filename, &stat);
583
584 if (!error)
585 error = cp_new_stat64(&stat, statbuf);
586
587 return error;
588}
589
590SYSCALL_DEFINE2(lstat64, const char __user *, filename,
591 struct stat64 __user *, statbuf)
592{
593 struct kstat stat;
594 int error = vfs_lstat(filename, &stat);
595
596 if (!error)
597 error = cp_new_stat64(&stat, statbuf);
598
599 return error;
600}
601
602SYSCALL_DEFINE2(fstat64, unsigned long, fd, struct stat64 __user *, statbuf)
603{
604 struct kstat stat;
605 int error = vfs_fstat(fd, &stat);
606
607 if (!error)
608 error = cp_new_stat64(&stat, statbuf);
609
610 return error;
611}
612
613SYSCALL_DEFINE4(fstatat64, int, dfd, const char __user *, filename,
614 struct stat64 __user *, statbuf, int, flag)
615{
616 struct kstat stat;
617 int error;
618
619 error = vfs_fstatat(dfd, filename, &stat, flag);
620 if (error)
621 return error;
622 return cp_new_stat64(&stat, statbuf);
623}
624#endif /* __ARCH_WANT_STAT64 || __ARCH_WANT_COMPAT_STAT64 */
625
626static noinline_for_stack int
627cp_statx(const struct kstat *stat, struct statx __user *buffer)
628{
629 struct statx tmp;
630
631 memset(&tmp, 0, sizeof(tmp));
632
633 /* STATX_CHANGE_COOKIE is kernel-only for now */
634 tmp.stx_mask = stat->result_mask & ~STATX_CHANGE_COOKIE;
635 tmp.stx_blksize = stat->blksize;
636 /* STATX_ATTR_CHANGE_MONOTONIC is kernel-only for now */
637 tmp.stx_attributes = stat->attributes & ~STATX_ATTR_CHANGE_MONOTONIC;
638 tmp.stx_nlink = stat->nlink;
639 tmp.stx_uid = from_kuid_munged(current_user_ns(), stat->uid);
640 tmp.stx_gid = from_kgid_munged(current_user_ns(), stat->gid);
641 tmp.stx_mode = stat->mode;
642 tmp.stx_ino = stat->ino;
643 tmp.stx_size = stat->size;
644 tmp.stx_blocks = stat->blocks;
645 tmp.stx_attributes_mask = stat->attributes_mask;
646 tmp.stx_atime.tv_sec = stat->atime.tv_sec;
647 tmp.stx_atime.tv_nsec = stat->atime.tv_nsec;
648 tmp.stx_btime.tv_sec = stat->btime.tv_sec;
649 tmp.stx_btime.tv_nsec = stat->btime.tv_nsec;
650 tmp.stx_ctime.tv_sec = stat->ctime.tv_sec;
651 tmp.stx_ctime.tv_nsec = stat->ctime.tv_nsec;
652 tmp.stx_mtime.tv_sec = stat->mtime.tv_sec;
653 tmp.stx_mtime.tv_nsec = stat->mtime.tv_nsec;
654 tmp.stx_rdev_major = MAJOR(stat->rdev);
655 tmp.stx_rdev_minor = MINOR(stat->rdev);
656 tmp.stx_dev_major = MAJOR(stat->dev);
657 tmp.stx_dev_minor = MINOR(stat->dev);
658 tmp.stx_mnt_id = stat->mnt_id;
659 tmp.stx_dio_mem_align = stat->dio_mem_align;
660 tmp.stx_dio_offset_align = stat->dio_offset_align;
661
662 return copy_to_user(buffer, &tmp, sizeof(tmp)) ? -EFAULT : 0;
663}
664
665int do_statx(int dfd, struct filename *filename, unsigned int flags,
666 unsigned int mask, struct statx __user *buffer)
667{
668 struct kstat stat;
669 int error;
670
671 if (mask & STATX__RESERVED)
672 return -EINVAL;
673 if ((flags & AT_STATX_SYNC_TYPE) == AT_STATX_SYNC_TYPE)
674 return -EINVAL;
675
676 /* STATX_CHANGE_COOKIE is kernel-only for now. Ignore requests
677 * from userland.
678 */
679 mask &= ~STATX_CHANGE_COOKIE;
680
681 error = vfs_statx(dfd, filename, flags, &stat, mask);
682 if (error)
683 return error;
684
685 return cp_statx(&stat, buffer);
686}
687
688/**
689 * sys_statx - System call to get enhanced stats
690 * @dfd: Base directory to pathwalk from *or* fd to stat.
691 * @filename: File to stat or "" with AT_EMPTY_PATH
692 * @flags: AT_* flags to control pathwalk.
693 * @mask: Parts of statx struct actually required.
694 * @buffer: Result buffer.
695 *
696 * Note that fstat() can be emulated by setting dfd to the fd of interest,
697 * supplying "" as the filename and setting AT_EMPTY_PATH in the flags.
698 */
699SYSCALL_DEFINE5(statx,
700 int, dfd, const char __user *, filename, unsigned, flags,
701 unsigned int, mask,
702 struct statx __user *, buffer)
703{
704 int ret;
705 struct filename *name;
706
707 name = getname_flags(filename, getname_statx_lookup_flags(flags), NULL);
708 ret = do_statx(dfd, name, flags, mask, buffer);
709 putname(name);
710
711 return ret;
712}
713
714#if defined(CONFIG_COMPAT) && defined(__ARCH_WANT_COMPAT_STAT)
715static int cp_compat_stat(struct kstat *stat, struct compat_stat __user *ubuf)
716{
717 struct compat_stat tmp;
718
719 if (sizeof(tmp.st_dev) < 4 && !old_valid_dev(stat->dev))
720 return -EOVERFLOW;
721 if (sizeof(tmp.st_rdev) < 4 && !old_valid_dev(stat->rdev))
722 return -EOVERFLOW;
723
724 memset(&tmp, 0, sizeof(tmp));
725 tmp.st_dev = new_encode_dev(stat->dev);
726 tmp.st_ino = stat->ino;
727 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
728 return -EOVERFLOW;
729 tmp.st_mode = stat->mode;
730 tmp.st_nlink = stat->nlink;
731 if (tmp.st_nlink != stat->nlink)
732 return -EOVERFLOW;
733 SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
734 SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
735 tmp.st_rdev = new_encode_dev(stat->rdev);
736 if ((u64) stat->size > MAX_NON_LFS)
737 return -EOVERFLOW;
738 tmp.st_size = stat->size;
739 tmp.st_atime = stat->atime.tv_sec;
740 tmp.st_atime_nsec = stat->atime.tv_nsec;
741 tmp.st_mtime = stat->mtime.tv_sec;
742 tmp.st_mtime_nsec = stat->mtime.tv_nsec;
743 tmp.st_ctime = stat->ctime.tv_sec;
744 tmp.st_ctime_nsec = stat->ctime.tv_nsec;
745 tmp.st_blocks = stat->blocks;
746 tmp.st_blksize = stat->blksize;
747 return copy_to_user(ubuf, &tmp, sizeof(tmp)) ? -EFAULT : 0;
748}
749
750COMPAT_SYSCALL_DEFINE2(newstat, const char __user *, filename,
751 struct compat_stat __user *, statbuf)
752{
753 struct kstat stat;
754 int error;
755
756 error = vfs_stat(filename, &stat);
757 if (error)
758 return error;
759 return cp_compat_stat(&stat, statbuf);
760}
761
762COMPAT_SYSCALL_DEFINE2(newlstat, const char __user *, filename,
763 struct compat_stat __user *, statbuf)
764{
765 struct kstat stat;
766 int error;
767
768 error = vfs_lstat(filename, &stat);
769 if (error)
770 return error;
771 return cp_compat_stat(&stat, statbuf);
772}
773
774#ifndef __ARCH_WANT_STAT64
775COMPAT_SYSCALL_DEFINE4(newfstatat, unsigned int, dfd,
776 const char __user *, filename,
777 struct compat_stat __user *, statbuf, int, flag)
778{
779 struct kstat stat;
780 int error;
781
782 error = vfs_fstatat(dfd, filename, &stat, flag);
783 if (error)
784 return error;
785 return cp_compat_stat(&stat, statbuf);
786}
787#endif
788
789COMPAT_SYSCALL_DEFINE2(newfstat, unsigned int, fd,
790 struct compat_stat __user *, statbuf)
791{
792 struct kstat stat;
793 int error = vfs_fstat(fd, &stat);
794
795 if (!error)
796 error = cp_compat_stat(&stat, statbuf);
797 return error;
798}
799#endif
800
801/* Caller is here responsible for sufficient locking (ie. inode->i_lock) */
802void __inode_add_bytes(struct inode *inode, loff_t bytes)
803{
804 inode->i_blocks += bytes >> 9;
805 bytes &= 511;
806 inode->i_bytes += bytes;
807 if (inode->i_bytes >= 512) {
808 inode->i_blocks++;
809 inode->i_bytes -= 512;
810 }
811}
812EXPORT_SYMBOL(__inode_add_bytes);
813
814void inode_add_bytes(struct inode *inode, loff_t bytes)
815{
816 spin_lock(&inode->i_lock);
817 __inode_add_bytes(inode, bytes);
818 spin_unlock(&inode->i_lock);
819}
820
821EXPORT_SYMBOL(inode_add_bytes);
822
823void __inode_sub_bytes(struct inode *inode, loff_t bytes)
824{
825 inode->i_blocks -= bytes >> 9;
826 bytes &= 511;
827 if (inode->i_bytes < bytes) {
828 inode->i_blocks--;
829 inode->i_bytes += 512;
830 }
831 inode->i_bytes -= bytes;
832}
833
834EXPORT_SYMBOL(__inode_sub_bytes);
835
836void inode_sub_bytes(struct inode *inode, loff_t bytes)
837{
838 spin_lock(&inode->i_lock);
839 __inode_sub_bytes(inode, bytes);
840 spin_unlock(&inode->i_lock);
841}
842
843EXPORT_SYMBOL(inode_sub_bytes);
844
845loff_t inode_get_bytes(struct inode *inode)
846{
847 loff_t ret;
848
849 spin_lock(&inode->i_lock);
850 ret = __inode_get_bytes(inode);
851 spin_unlock(&inode->i_lock);
852 return ret;
853}
854
855EXPORT_SYMBOL(inode_get_bytes);
856
857void inode_set_bytes(struct inode *inode, loff_t bytes)
858{
859 /* Caller is here responsible for sufficient locking
860 * (ie. inode->i_lock) */
861 inode->i_blocks = bytes >> 9;
862 inode->i_bytes = bytes & 511;
863}
864
865EXPORT_SYMBOL(inode_set_bytes);