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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/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 <trace/events/timestamp.h>
27
28#include "internal.h"
29#include "mount.h"
30
31/**
32 * fill_mg_cmtime - Fill in the mtime and ctime and flag ctime as QUERIED
33 * @stat: where to store the resulting values
34 * @request_mask: STATX_* values requested
35 * @inode: inode from which to grab the c/mtime
36 *
37 * Given @inode, grab the ctime and mtime out if it and store the result
38 * in @stat. When fetching the value, flag it as QUERIED (if not already)
39 * so the next write will record a distinct timestamp.
40 *
41 * NB: The QUERIED flag is tracked in the ctime, but we set it there even
42 * if only the mtime was requested, as that ensures that the next mtime
43 * change will be distinct.
44 */
45void fill_mg_cmtime(struct kstat *stat, u32 request_mask, struct inode *inode)
46{
47 atomic_t *pcn = (atomic_t *)&inode->i_ctime_nsec;
48
49 /* If neither time was requested, then don't report them */
50 if (!(request_mask & (STATX_CTIME|STATX_MTIME))) {
51 stat->result_mask &= ~(STATX_CTIME|STATX_MTIME);
52 return;
53 }
54
55 stat->mtime = inode_get_mtime(inode);
56 stat->ctime.tv_sec = inode->i_ctime_sec;
57 stat->ctime.tv_nsec = (u32)atomic_read(pcn);
58 if (!(stat->ctime.tv_nsec & I_CTIME_QUERIED))
59 stat->ctime.tv_nsec = ((u32)atomic_fetch_or(I_CTIME_QUERIED, pcn));
60 stat->ctime.tv_nsec &= ~I_CTIME_QUERIED;
61 trace_fill_mg_cmtime(inode, &stat->ctime, &stat->mtime);
62}
63EXPORT_SYMBOL(fill_mg_cmtime);
64
65/**
66 * generic_fillattr - Fill in the basic attributes from the inode struct
67 * @idmap: idmap of the mount the inode was found from
68 * @request_mask: statx request_mask
69 * @inode: Inode to use as the source
70 * @stat: Where to fill in the attributes
71 *
72 * Fill in the basic attributes in the kstat structure from data that's to be
73 * found on the VFS inode structure. This is the default if no getattr inode
74 * operation is supplied.
75 *
76 * If the inode has been found through an idmapped mount the idmap of
77 * the vfsmount must be passed through @idmap. This function will then
78 * take care to map the inode according to @idmap before filling in the
79 * uid and gid filds. On non-idmapped mounts or if permission checking is to be
80 * performed on the raw inode simply pass @nop_mnt_idmap.
81 */
82void generic_fillattr(struct mnt_idmap *idmap, u32 request_mask,
83 struct inode *inode, struct kstat *stat)
84{
85 vfsuid_t vfsuid = i_uid_into_vfsuid(idmap, inode);
86 vfsgid_t vfsgid = i_gid_into_vfsgid(idmap, inode);
87
88 stat->dev = inode->i_sb->s_dev;
89 stat->ino = inode->i_ino;
90 stat->mode = inode->i_mode;
91 stat->nlink = inode->i_nlink;
92 stat->uid = vfsuid_into_kuid(vfsuid);
93 stat->gid = vfsgid_into_kgid(vfsgid);
94 stat->rdev = inode->i_rdev;
95 stat->size = i_size_read(inode);
96 stat->atime = inode_get_atime(inode);
97
98 if (is_mgtime(inode)) {
99 fill_mg_cmtime(stat, request_mask, inode);
100 } else {
101 stat->ctime = inode_get_ctime(inode);
102 stat->mtime = inode_get_mtime(inode);
103 }
104
105 stat->blksize = i_blocksize(inode);
106 stat->blocks = inode->i_blocks;
107
108 if ((request_mask & STATX_CHANGE_COOKIE) && IS_I_VERSION(inode)) {
109 stat->result_mask |= STATX_CHANGE_COOKIE;
110 stat->change_cookie = inode_query_iversion(inode);
111 }
112
113}
114EXPORT_SYMBOL(generic_fillattr);
115
116/**
117 * generic_fill_statx_attr - Fill in the statx attributes from the inode flags
118 * @inode: Inode to use as the source
119 * @stat: Where to fill in the attribute flags
120 *
121 * Fill in the STATX_ATTR_* flags in the kstat structure for properties of the
122 * inode that are published on i_flags and enforced by the VFS.
123 */
124void generic_fill_statx_attr(struct inode *inode, struct kstat *stat)
125{
126 if (inode->i_flags & S_IMMUTABLE)
127 stat->attributes |= STATX_ATTR_IMMUTABLE;
128 if (inode->i_flags & S_APPEND)
129 stat->attributes |= STATX_ATTR_APPEND;
130 stat->attributes_mask |= KSTAT_ATTR_VFS_FLAGS;
131}
132EXPORT_SYMBOL(generic_fill_statx_attr);
133
134/**
135 * generic_fill_statx_atomic_writes - Fill in atomic writes statx attributes
136 * @stat: Where to fill in the attribute flags
137 * @unit_min: Minimum supported atomic write length in bytes
138 * @unit_max: Maximum supported atomic write length in bytes
139 *
140 * Fill in the STATX{_ATTR}_WRITE_ATOMIC flags in the kstat structure from
141 * atomic write unit_min and unit_max values.
142 */
143void generic_fill_statx_atomic_writes(struct kstat *stat,
144 unsigned int unit_min,
145 unsigned int unit_max)
146{
147 /* Confirm that the request type is known */
148 stat->result_mask |= STATX_WRITE_ATOMIC;
149
150 /* Confirm that the file attribute type is known */
151 stat->attributes_mask |= STATX_ATTR_WRITE_ATOMIC;
152
153 if (unit_min) {
154 stat->atomic_write_unit_min = unit_min;
155 stat->atomic_write_unit_max = unit_max;
156 /* Initially only allow 1x segment */
157 stat->atomic_write_segments_max = 1;
158
159 /* Confirm atomic writes are actually supported */
160 stat->attributes |= STATX_ATTR_WRITE_ATOMIC;
161 }
162}
163EXPORT_SYMBOL_GPL(generic_fill_statx_atomic_writes);
164
165/**
166 * vfs_getattr_nosec - getattr without security checks
167 * @path: file to get attributes from
168 * @stat: structure to return attributes in
169 * @request_mask: STATX_xxx flags indicating what the caller wants
170 * @query_flags: Query mode (AT_STATX_SYNC_TYPE)
171 *
172 * Get attributes without calling security_inode_getattr.
173 *
174 * Currently the only caller other than vfs_getattr is internal to the
175 * filehandle lookup code, which uses only the inode number and returns no
176 * attributes to any user. Any other code probably wants vfs_getattr.
177 */
178int vfs_getattr_nosec(const struct path *path, struct kstat *stat,
179 u32 request_mask, unsigned int query_flags)
180{
181 struct mnt_idmap *idmap;
182 struct inode *inode = d_backing_inode(path->dentry);
183
184 memset(stat, 0, sizeof(*stat));
185 stat->result_mask |= STATX_BASIC_STATS;
186 query_flags &= AT_STATX_SYNC_TYPE;
187
188 /* allow the fs to override these if it really wants to */
189 /* SB_NOATIME means filesystem supplies dummy atime value */
190 if (inode->i_sb->s_flags & SB_NOATIME)
191 stat->result_mask &= ~STATX_ATIME;
192
193 /*
194 * Note: If you add another clause to set an attribute flag, please
195 * update attributes_mask below.
196 */
197 if (IS_AUTOMOUNT(inode))
198 stat->attributes |= STATX_ATTR_AUTOMOUNT;
199
200 if (IS_DAX(inode))
201 stat->attributes |= STATX_ATTR_DAX;
202
203 stat->attributes_mask |= (STATX_ATTR_AUTOMOUNT |
204 STATX_ATTR_DAX);
205
206 idmap = mnt_idmap(path->mnt);
207 if (inode->i_op->getattr)
208 return inode->i_op->getattr(idmap, path, stat,
209 request_mask,
210 query_flags);
211
212 generic_fillattr(idmap, request_mask, inode, stat);
213 return 0;
214}
215EXPORT_SYMBOL(vfs_getattr_nosec);
216
217/*
218 * vfs_getattr - Get the enhanced basic attributes of a file
219 * @path: The file of interest
220 * @stat: Where to return the statistics
221 * @request_mask: STATX_xxx flags indicating what the caller wants
222 * @query_flags: Query mode (AT_STATX_SYNC_TYPE)
223 *
224 * Ask the filesystem for a file's attributes. The caller must indicate in
225 * request_mask and query_flags to indicate what they want.
226 *
227 * If the file is remote, the filesystem can be forced to update the attributes
228 * from the backing store by passing AT_STATX_FORCE_SYNC in query_flags or can
229 * suppress the update by passing AT_STATX_DONT_SYNC.
230 *
231 * Bits must have been set in request_mask to indicate which attributes the
232 * caller wants retrieving. Any such attribute not requested may be returned
233 * anyway, but the value may be approximate, and, if remote, may not have been
234 * synchronised with the server.
235 *
236 * 0 will be returned on success, and a -ve error code if unsuccessful.
237 */
238int vfs_getattr(const struct path *path, struct kstat *stat,
239 u32 request_mask, unsigned int query_flags)
240{
241 int retval;
242
243 retval = security_inode_getattr(path);
244 if (retval)
245 return retval;
246 return vfs_getattr_nosec(path, stat, request_mask, query_flags);
247}
248EXPORT_SYMBOL(vfs_getattr);
249
250/**
251 * vfs_fstat - Get the basic attributes by file descriptor
252 * @fd: The file descriptor referring to the file of interest
253 * @stat: The result structure to fill in.
254 *
255 * This function is a wrapper around vfs_getattr(). The main difference is
256 * that it uses a file descriptor to determine the file location.
257 *
258 * 0 will be returned on success, and a -ve error code if unsuccessful.
259 */
260int vfs_fstat(int fd, struct kstat *stat)
261{
262 CLASS(fd_raw, f)(fd);
263 if (fd_empty(f))
264 return -EBADF;
265 return vfs_getattr(&fd_file(f)->f_path, stat, STATX_BASIC_STATS, 0);
266}
267
268static int statx_lookup_flags(int flags)
269{
270 int lookup_flags = 0;
271
272 if (!(flags & AT_SYMLINK_NOFOLLOW))
273 lookup_flags |= LOOKUP_FOLLOW;
274 if (!(flags & AT_NO_AUTOMOUNT))
275 lookup_flags |= LOOKUP_AUTOMOUNT;
276
277 return lookup_flags;
278}
279
280static int vfs_statx_path(struct path *path, int flags, struct kstat *stat,
281 u32 request_mask)
282{
283 int error = vfs_getattr(path, stat, request_mask, flags);
284
285 if (request_mask & STATX_MNT_ID_UNIQUE) {
286 stat->mnt_id = real_mount(path->mnt)->mnt_id_unique;
287 stat->result_mask |= STATX_MNT_ID_UNIQUE;
288 } else {
289 stat->mnt_id = real_mount(path->mnt)->mnt_id;
290 stat->result_mask |= STATX_MNT_ID;
291 }
292
293 if (path_mounted(path))
294 stat->attributes |= STATX_ATTR_MOUNT_ROOT;
295 stat->attributes_mask |= STATX_ATTR_MOUNT_ROOT;
296
297 /*
298 * If this is a block device inode, override the filesystem
299 * attributes with the block device specific parameters that need to be
300 * obtained from the bdev backing inode.
301 */
302 if (S_ISBLK(stat->mode))
303 bdev_statx(path, stat, request_mask);
304
305 return error;
306}
307
308static int vfs_statx_fd(int fd, int flags, struct kstat *stat,
309 u32 request_mask)
310{
311 CLASS(fd_raw, f)(fd);
312 if (fd_empty(f))
313 return -EBADF;
314 return vfs_statx_path(&fd_file(f)->f_path, flags, stat, request_mask);
315}
316
317/**
318 * vfs_statx - Get basic and extra attributes by filename
319 * @dfd: A file descriptor representing the base dir for a relative filename
320 * @filename: The name of the file of interest
321 * @flags: Flags to control the query
322 * @stat: The result structure to fill in.
323 * @request_mask: STATX_xxx flags indicating what the caller wants
324 *
325 * This function is a wrapper around vfs_getattr(). The main difference is
326 * that it uses a filename and base directory to determine the file location.
327 * Additionally, the use of AT_SYMLINK_NOFOLLOW in flags will prevent a symlink
328 * at the given name from being referenced.
329 *
330 * 0 will be returned on success, and a -ve error code if unsuccessful.
331 */
332static int vfs_statx(int dfd, struct filename *filename, int flags,
333 struct kstat *stat, u32 request_mask)
334{
335 struct path path;
336 unsigned int lookup_flags = statx_lookup_flags(flags);
337 int error;
338
339 if (flags & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT | AT_EMPTY_PATH |
340 AT_STATX_SYNC_TYPE))
341 return -EINVAL;
342
343retry:
344 error = filename_lookup(dfd, filename, lookup_flags, &path, NULL);
345 if (error)
346 return error;
347 error = vfs_statx_path(&path, flags, stat, request_mask);
348 path_put(&path);
349 if (retry_estale(error, lookup_flags)) {
350 lookup_flags |= LOOKUP_REVAL;
351 goto retry;
352 }
353 return error;
354}
355
356int vfs_fstatat(int dfd, const char __user *filename,
357 struct kstat *stat, int flags)
358{
359 int ret;
360 int statx_flags = flags | AT_NO_AUTOMOUNT;
361 struct filename *name = getname_maybe_null(filename, flags);
362
363 if (!name && dfd >= 0)
364 return vfs_fstat(dfd, stat);
365
366 ret = vfs_statx(dfd, name, statx_flags, stat, STATX_BASIC_STATS);
367 putname(name);
368
369 return ret;
370}
371
372#ifdef __ARCH_WANT_OLD_STAT
373
374/*
375 * For backward compatibility? Maybe this should be moved
376 * into arch/i386 instead?
377 */
378static int cp_old_stat(struct kstat *stat, struct __old_kernel_stat __user * statbuf)
379{
380 static int warncount = 5;
381 struct __old_kernel_stat tmp;
382
383 if (warncount > 0) {
384 warncount--;
385 printk(KERN_WARNING "VFS: Warning: %s using old stat() call. Recompile your binary.\n",
386 current->comm);
387 } else if (warncount < 0) {
388 /* it's laughable, but... */
389 warncount = 0;
390 }
391
392 memset(&tmp, 0, sizeof(struct __old_kernel_stat));
393 tmp.st_dev = old_encode_dev(stat->dev);
394 tmp.st_ino = stat->ino;
395 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
396 return -EOVERFLOW;
397 tmp.st_mode = stat->mode;
398 tmp.st_nlink = stat->nlink;
399 if (tmp.st_nlink != stat->nlink)
400 return -EOVERFLOW;
401 SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
402 SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
403 tmp.st_rdev = old_encode_dev(stat->rdev);
404#if BITS_PER_LONG == 32
405 if (stat->size > MAX_NON_LFS)
406 return -EOVERFLOW;
407#endif
408 tmp.st_size = stat->size;
409 tmp.st_atime = stat->atime.tv_sec;
410 tmp.st_mtime = stat->mtime.tv_sec;
411 tmp.st_ctime = stat->ctime.tv_sec;
412 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
413}
414
415SYSCALL_DEFINE2(stat, const char __user *, filename,
416 struct __old_kernel_stat __user *, statbuf)
417{
418 struct kstat stat;
419 int error;
420
421 error = vfs_stat(filename, &stat);
422 if (error)
423 return error;
424
425 return cp_old_stat(&stat, statbuf);
426}
427
428SYSCALL_DEFINE2(lstat, const char __user *, filename,
429 struct __old_kernel_stat __user *, statbuf)
430{
431 struct kstat stat;
432 int error;
433
434 error = vfs_lstat(filename, &stat);
435 if (error)
436 return error;
437
438 return cp_old_stat(&stat, statbuf);
439}
440
441SYSCALL_DEFINE2(fstat, unsigned int, fd, struct __old_kernel_stat __user *, statbuf)
442{
443 struct kstat stat;
444 int error = vfs_fstat(fd, &stat);
445
446 if (!error)
447 error = cp_old_stat(&stat, statbuf);
448
449 return error;
450}
451
452#endif /* __ARCH_WANT_OLD_STAT */
453
454#ifdef __ARCH_WANT_NEW_STAT
455
456#ifndef INIT_STRUCT_STAT_PADDING
457# define INIT_STRUCT_STAT_PADDING(st) memset(&st, 0, sizeof(st))
458#endif
459
460static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf)
461{
462 struct stat tmp;
463
464 if (sizeof(tmp.st_dev) < 4 && !old_valid_dev(stat->dev))
465 return -EOVERFLOW;
466 if (sizeof(tmp.st_rdev) < 4 && !old_valid_dev(stat->rdev))
467 return -EOVERFLOW;
468#if BITS_PER_LONG == 32
469 if (stat->size > MAX_NON_LFS)
470 return -EOVERFLOW;
471#endif
472
473 INIT_STRUCT_STAT_PADDING(tmp);
474 tmp.st_dev = new_encode_dev(stat->dev);
475 tmp.st_ino = stat->ino;
476 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
477 return -EOVERFLOW;
478 tmp.st_mode = stat->mode;
479 tmp.st_nlink = stat->nlink;
480 if (tmp.st_nlink != stat->nlink)
481 return -EOVERFLOW;
482 SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
483 SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
484 tmp.st_rdev = new_encode_dev(stat->rdev);
485 tmp.st_size = stat->size;
486 tmp.st_atime = stat->atime.tv_sec;
487 tmp.st_mtime = stat->mtime.tv_sec;
488 tmp.st_ctime = stat->ctime.tv_sec;
489#ifdef STAT_HAVE_NSEC
490 tmp.st_atime_nsec = stat->atime.tv_nsec;
491 tmp.st_mtime_nsec = stat->mtime.tv_nsec;
492 tmp.st_ctime_nsec = stat->ctime.tv_nsec;
493#endif
494 tmp.st_blocks = stat->blocks;
495 tmp.st_blksize = stat->blksize;
496 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
497}
498
499SYSCALL_DEFINE2(newstat, const char __user *, filename,
500 struct stat __user *, statbuf)
501{
502 struct kstat stat;
503 int error = vfs_stat(filename, &stat);
504
505 if (error)
506 return error;
507 return cp_new_stat(&stat, statbuf);
508}
509
510SYSCALL_DEFINE2(newlstat, const char __user *, filename,
511 struct stat __user *, statbuf)
512{
513 struct kstat stat;
514 int error;
515
516 error = vfs_lstat(filename, &stat);
517 if (error)
518 return error;
519
520 return cp_new_stat(&stat, statbuf);
521}
522
523#if !defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_SYS_NEWFSTATAT)
524SYSCALL_DEFINE4(newfstatat, int, dfd, const char __user *, filename,
525 struct stat __user *, statbuf, int, flag)
526{
527 struct kstat stat;
528 int error;
529
530 error = vfs_fstatat(dfd, filename, &stat, flag);
531 if (error)
532 return error;
533 return cp_new_stat(&stat, statbuf);
534}
535#endif
536
537SYSCALL_DEFINE2(newfstat, unsigned int, fd, struct stat __user *, statbuf)
538{
539 struct kstat stat;
540 int error = vfs_fstat(fd, &stat);
541
542 if (!error)
543 error = cp_new_stat(&stat, statbuf);
544
545 return error;
546}
547#endif
548
549static int do_readlinkat(int dfd, const char __user *pathname,
550 char __user *buf, int bufsiz)
551{
552 struct path path;
553 struct filename *name;
554 int error;
555 unsigned int lookup_flags = LOOKUP_EMPTY;
556
557 if (bufsiz <= 0)
558 return -EINVAL;
559
560retry:
561 name = getname_flags(pathname, lookup_flags);
562 error = filename_lookup(dfd, name, lookup_flags, &path, NULL);
563 if (unlikely(error)) {
564 putname(name);
565 return error;
566 }
567
568 /*
569 * AFS mountpoints allow readlink(2) but are not symlinks
570 */
571 if (d_is_symlink(path.dentry) ||
572 d_backing_inode(path.dentry)->i_op->readlink) {
573 error = security_inode_readlink(path.dentry);
574 if (!error) {
575 touch_atime(&path);
576 error = vfs_readlink(path.dentry, buf, bufsiz);
577 }
578 } else {
579 error = (name->name[0] == '\0') ? -ENOENT : -EINVAL;
580 }
581 path_put(&path);
582 putname(name);
583 if (retry_estale(error, lookup_flags)) {
584 lookup_flags |= LOOKUP_REVAL;
585 goto retry;
586 }
587 return error;
588}
589
590SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname,
591 char __user *, buf, int, bufsiz)
592{
593 return do_readlinkat(dfd, pathname, buf, bufsiz);
594}
595
596SYSCALL_DEFINE3(readlink, const char __user *, path, char __user *, buf,
597 int, bufsiz)
598{
599 return do_readlinkat(AT_FDCWD, path, buf, bufsiz);
600}
601
602
603/* ---------- LFS-64 ----------- */
604#if defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_COMPAT_STAT64)
605
606#ifndef INIT_STRUCT_STAT64_PADDING
607# define INIT_STRUCT_STAT64_PADDING(st) memset(&st, 0, sizeof(st))
608#endif
609
610static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf)
611{
612 struct stat64 tmp;
613
614 INIT_STRUCT_STAT64_PADDING(tmp);
615#ifdef CONFIG_MIPS
616 /* mips has weird padding, so we don't get 64 bits there */
617 tmp.st_dev = new_encode_dev(stat->dev);
618 tmp.st_rdev = new_encode_dev(stat->rdev);
619#else
620 tmp.st_dev = huge_encode_dev(stat->dev);
621 tmp.st_rdev = huge_encode_dev(stat->rdev);
622#endif
623 tmp.st_ino = stat->ino;
624 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
625 return -EOVERFLOW;
626#ifdef STAT64_HAS_BROKEN_ST_INO
627 tmp.__st_ino = stat->ino;
628#endif
629 tmp.st_mode = stat->mode;
630 tmp.st_nlink = stat->nlink;
631 tmp.st_uid = from_kuid_munged(current_user_ns(), stat->uid);
632 tmp.st_gid = from_kgid_munged(current_user_ns(), stat->gid);
633 tmp.st_atime = stat->atime.tv_sec;
634 tmp.st_atime_nsec = stat->atime.tv_nsec;
635 tmp.st_mtime = stat->mtime.tv_sec;
636 tmp.st_mtime_nsec = stat->mtime.tv_nsec;
637 tmp.st_ctime = stat->ctime.tv_sec;
638 tmp.st_ctime_nsec = stat->ctime.tv_nsec;
639 tmp.st_size = stat->size;
640 tmp.st_blocks = stat->blocks;
641 tmp.st_blksize = stat->blksize;
642 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
643}
644
645SYSCALL_DEFINE2(stat64, const char __user *, filename,
646 struct stat64 __user *, statbuf)
647{
648 struct kstat stat;
649 int error = vfs_stat(filename, &stat);
650
651 if (!error)
652 error = cp_new_stat64(&stat, statbuf);
653
654 return error;
655}
656
657SYSCALL_DEFINE2(lstat64, const char __user *, filename,
658 struct stat64 __user *, statbuf)
659{
660 struct kstat stat;
661 int error = vfs_lstat(filename, &stat);
662
663 if (!error)
664 error = cp_new_stat64(&stat, statbuf);
665
666 return error;
667}
668
669SYSCALL_DEFINE2(fstat64, unsigned long, fd, struct stat64 __user *, statbuf)
670{
671 struct kstat stat;
672 int error = vfs_fstat(fd, &stat);
673
674 if (!error)
675 error = cp_new_stat64(&stat, statbuf);
676
677 return error;
678}
679
680SYSCALL_DEFINE4(fstatat64, int, dfd, const char __user *, filename,
681 struct stat64 __user *, statbuf, int, flag)
682{
683 struct kstat stat;
684 int error;
685
686 error = vfs_fstatat(dfd, filename, &stat, flag);
687 if (error)
688 return error;
689 return cp_new_stat64(&stat, statbuf);
690}
691#endif /* __ARCH_WANT_STAT64 || __ARCH_WANT_COMPAT_STAT64 */
692
693static noinline_for_stack int
694cp_statx(const struct kstat *stat, struct statx __user *buffer)
695{
696 struct statx tmp;
697
698 memset(&tmp, 0, sizeof(tmp));
699
700 /* STATX_CHANGE_COOKIE is kernel-only for now */
701 tmp.stx_mask = stat->result_mask & ~STATX_CHANGE_COOKIE;
702 tmp.stx_blksize = stat->blksize;
703 /* STATX_ATTR_CHANGE_MONOTONIC is kernel-only for now */
704 tmp.stx_attributes = stat->attributes & ~STATX_ATTR_CHANGE_MONOTONIC;
705 tmp.stx_nlink = stat->nlink;
706 tmp.stx_uid = from_kuid_munged(current_user_ns(), stat->uid);
707 tmp.stx_gid = from_kgid_munged(current_user_ns(), stat->gid);
708 tmp.stx_mode = stat->mode;
709 tmp.stx_ino = stat->ino;
710 tmp.stx_size = stat->size;
711 tmp.stx_blocks = stat->blocks;
712 tmp.stx_attributes_mask = stat->attributes_mask;
713 tmp.stx_atime.tv_sec = stat->atime.tv_sec;
714 tmp.stx_atime.tv_nsec = stat->atime.tv_nsec;
715 tmp.stx_btime.tv_sec = stat->btime.tv_sec;
716 tmp.stx_btime.tv_nsec = stat->btime.tv_nsec;
717 tmp.stx_ctime.tv_sec = stat->ctime.tv_sec;
718 tmp.stx_ctime.tv_nsec = stat->ctime.tv_nsec;
719 tmp.stx_mtime.tv_sec = stat->mtime.tv_sec;
720 tmp.stx_mtime.tv_nsec = stat->mtime.tv_nsec;
721 tmp.stx_rdev_major = MAJOR(stat->rdev);
722 tmp.stx_rdev_minor = MINOR(stat->rdev);
723 tmp.stx_dev_major = MAJOR(stat->dev);
724 tmp.stx_dev_minor = MINOR(stat->dev);
725 tmp.stx_mnt_id = stat->mnt_id;
726 tmp.stx_dio_mem_align = stat->dio_mem_align;
727 tmp.stx_dio_offset_align = stat->dio_offset_align;
728 tmp.stx_subvol = stat->subvol;
729 tmp.stx_atomic_write_unit_min = stat->atomic_write_unit_min;
730 tmp.stx_atomic_write_unit_max = stat->atomic_write_unit_max;
731 tmp.stx_atomic_write_segments_max = stat->atomic_write_segments_max;
732
733 return copy_to_user(buffer, &tmp, sizeof(tmp)) ? -EFAULT : 0;
734}
735
736int do_statx(int dfd, struct filename *filename, unsigned int flags,
737 unsigned int mask, struct statx __user *buffer)
738{
739 struct kstat stat;
740 int error;
741
742 if (mask & STATX__RESERVED)
743 return -EINVAL;
744 if ((flags & AT_STATX_SYNC_TYPE) == AT_STATX_SYNC_TYPE)
745 return -EINVAL;
746
747 /*
748 * STATX_CHANGE_COOKIE is kernel-only for now. Ignore requests
749 * from userland.
750 */
751 mask &= ~STATX_CHANGE_COOKIE;
752
753 error = vfs_statx(dfd, filename, flags, &stat, mask);
754 if (error)
755 return error;
756
757 return cp_statx(&stat, buffer);
758}
759
760int do_statx_fd(int fd, unsigned int flags, unsigned int mask,
761 struct statx __user *buffer)
762{
763 struct kstat stat;
764 int error;
765
766 if (mask & STATX__RESERVED)
767 return -EINVAL;
768 if ((flags & AT_STATX_SYNC_TYPE) == AT_STATX_SYNC_TYPE)
769 return -EINVAL;
770
771 /*
772 * STATX_CHANGE_COOKIE is kernel-only for now. Ignore requests
773 * from userland.
774 */
775 mask &= ~STATX_CHANGE_COOKIE;
776
777 error = vfs_statx_fd(fd, flags, &stat, mask);
778 if (error)
779 return error;
780
781 return cp_statx(&stat, buffer);
782}
783
784/**
785 * sys_statx - System call to get enhanced stats
786 * @dfd: Base directory to pathwalk from *or* fd to stat.
787 * @filename: File to stat or either NULL or "" with AT_EMPTY_PATH
788 * @flags: AT_* flags to control pathwalk.
789 * @mask: Parts of statx struct actually required.
790 * @buffer: Result buffer.
791 *
792 * Note that fstat() can be emulated by setting dfd to the fd of interest,
793 * supplying "" (or preferably NULL) as the filename and setting AT_EMPTY_PATH
794 * in the flags.
795 */
796SYSCALL_DEFINE5(statx,
797 int, dfd, const char __user *, filename, unsigned, flags,
798 unsigned int, mask,
799 struct statx __user *, buffer)
800{
801 int ret;
802 struct filename *name = getname_maybe_null(filename, flags);
803
804 if (!name && dfd >= 0)
805 return do_statx_fd(dfd, flags & ~AT_NO_AUTOMOUNT, mask, buffer);
806
807 ret = do_statx(dfd, name, flags, mask, buffer);
808 putname(name);
809
810 return ret;
811}
812
813#if defined(CONFIG_COMPAT) && defined(__ARCH_WANT_COMPAT_STAT)
814static int cp_compat_stat(struct kstat *stat, struct compat_stat __user *ubuf)
815{
816 struct compat_stat tmp;
817
818 if (sizeof(tmp.st_dev) < 4 && !old_valid_dev(stat->dev))
819 return -EOVERFLOW;
820 if (sizeof(tmp.st_rdev) < 4 && !old_valid_dev(stat->rdev))
821 return -EOVERFLOW;
822
823 memset(&tmp, 0, sizeof(tmp));
824 tmp.st_dev = new_encode_dev(stat->dev);
825 tmp.st_ino = stat->ino;
826 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
827 return -EOVERFLOW;
828 tmp.st_mode = stat->mode;
829 tmp.st_nlink = stat->nlink;
830 if (tmp.st_nlink != stat->nlink)
831 return -EOVERFLOW;
832 SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
833 SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
834 tmp.st_rdev = new_encode_dev(stat->rdev);
835 if ((u64) stat->size > MAX_NON_LFS)
836 return -EOVERFLOW;
837 tmp.st_size = stat->size;
838 tmp.st_atime = stat->atime.tv_sec;
839 tmp.st_atime_nsec = stat->atime.tv_nsec;
840 tmp.st_mtime = stat->mtime.tv_sec;
841 tmp.st_mtime_nsec = stat->mtime.tv_nsec;
842 tmp.st_ctime = stat->ctime.tv_sec;
843 tmp.st_ctime_nsec = stat->ctime.tv_nsec;
844 tmp.st_blocks = stat->blocks;
845 tmp.st_blksize = stat->blksize;
846 return copy_to_user(ubuf, &tmp, sizeof(tmp)) ? -EFAULT : 0;
847}
848
849COMPAT_SYSCALL_DEFINE2(newstat, const char __user *, filename,
850 struct compat_stat __user *, statbuf)
851{
852 struct kstat stat;
853 int error;
854
855 error = vfs_stat(filename, &stat);
856 if (error)
857 return error;
858 return cp_compat_stat(&stat, statbuf);
859}
860
861COMPAT_SYSCALL_DEFINE2(newlstat, const char __user *, filename,
862 struct compat_stat __user *, statbuf)
863{
864 struct kstat stat;
865 int error;
866
867 error = vfs_lstat(filename, &stat);
868 if (error)
869 return error;
870 return cp_compat_stat(&stat, statbuf);
871}
872
873#ifndef __ARCH_WANT_STAT64
874COMPAT_SYSCALL_DEFINE4(newfstatat, unsigned int, dfd,
875 const char __user *, filename,
876 struct compat_stat __user *, statbuf, int, flag)
877{
878 struct kstat stat;
879 int error;
880
881 error = vfs_fstatat(dfd, filename, &stat, flag);
882 if (error)
883 return error;
884 return cp_compat_stat(&stat, statbuf);
885}
886#endif
887
888COMPAT_SYSCALL_DEFINE2(newfstat, unsigned int, fd,
889 struct compat_stat __user *, statbuf)
890{
891 struct kstat stat;
892 int error = vfs_fstat(fd, &stat);
893
894 if (!error)
895 error = cp_compat_stat(&stat, statbuf);
896 return error;
897}
898#endif
899
900/* Caller is here responsible for sufficient locking (ie. inode->i_lock) */
901void __inode_add_bytes(struct inode *inode, loff_t bytes)
902{
903 inode->i_blocks += bytes >> 9;
904 bytes &= 511;
905 inode->i_bytes += bytes;
906 if (inode->i_bytes >= 512) {
907 inode->i_blocks++;
908 inode->i_bytes -= 512;
909 }
910}
911EXPORT_SYMBOL(__inode_add_bytes);
912
913void inode_add_bytes(struct inode *inode, loff_t bytes)
914{
915 spin_lock(&inode->i_lock);
916 __inode_add_bytes(inode, bytes);
917 spin_unlock(&inode->i_lock);
918}
919
920EXPORT_SYMBOL(inode_add_bytes);
921
922void __inode_sub_bytes(struct inode *inode, loff_t bytes)
923{
924 inode->i_blocks -= bytes >> 9;
925 bytes &= 511;
926 if (inode->i_bytes < bytes) {
927 inode->i_blocks--;
928 inode->i_bytes += 512;
929 }
930 inode->i_bytes -= bytes;
931}
932
933EXPORT_SYMBOL(__inode_sub_bytes);
934
935void inode_sub_bytes(struct inode *inode, loff_t bytes)
936{
937 spin_lock(&inode->i_lock);
938 __inode_sub_bytes(inode, bytes);
939 spin_unlock(&inode->i_lock);
940}
941
942EXPORT_SYMBOL(inode_sub_bytes);
943
944loff_t inode_get_bytes(struct inode *inode)
945{
946 loff_t ret;
947
948 spin_lock(&inode->i_lock);
949 ret = __inode_get_bytes(inode);
950 spin_unlock(&inode->i_lock);
951 return ret;
952}
953
954EXPORT_SYMBOL(inode_get_bytes);
955
956void inode_set_bytes(struct inode *inode, loff_t bytes)
957{
958 /* Caller is here responsible for sufficient locking
959 * (ie. inode->i_lock) */
960 inode->i_blocks = bytes >> 9;
961 inode->i_bytes = bytes & 511;
962}
963
964EXPORT_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);