projects/linux·blob v7.3 · refs

968 lines · 26.6 KiB

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_get_ctime_sec(inode);
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 * @unit_max_opt: Optimised maximum supported atomic write length in bytes
140 *
141 * Fill in the STATX{_ATTR}_WRITE_ATOMIC flags in the kstat structure from
142 * atomic write unit_min and unit_max values.
143 */
144void generic_fill_statx_atomic_writes(struct kstat *stat,
145 unsigned int unit_min,
146 unsigned int unit_max,
147 unsigned int unit_max_opt)
148{
149 /* Confirm that the request type is known */
150 stat->result_mask |= STATX_WRITE_ATOMIC;
151
152 /* Confirm that the file attribute type is known */
153 stat->attributes_mask |= STATX_ATTR_WRITE_ATOMIC;
154
155 if (unit_min) {
156 stat->atomic_write_unit_min = unit_min;
157 stat->atomic_write_unit_max = unit_max;
158 stat->atomic_write_unit_max_opt = unit_max_opt;
159 /* Initially only allow 1x segment */
160 stat->atomic_write_segments_max = 1;
161
162 /* Confirm atomic writes are actually supported */
163 stat->attributes |= STATX_ATTR_WRITE_ATOMIC;
164 }
165}
166EXPORT_SYMBOL_GPL(generic_fill_statx_atomic_writes);
167
168/**
169 * vfs_getattr_nosec - getattr without security checks
170 * @path: file to get attributes from
171 * @stat: structure to return attributes in
172 * @request_mask: STATX_xxx flags indicating what the caller wants
173 * @query_flags: Query mode (AT_STATX_SYNC_TYPE)
174 *
175 * Get attributes without calling security_inode_getattr.
176 *
177 * Currently the only caller other than vfs_getattr is internal to the
178 * filehandle lookup code, which uses only the inode number and returns no
179 * attributes to any user. Any other code probably wants vfs_getattr.
180 */
181int vfs_getattr_nosec(const struct path *path, struct kstat *stat,
182 u32 request_mask, unsigned int query_flags)
183{
184 struct mnt_idmap *idmap;
185 struct inode *inode = d_backing_inode(path->dentry);
186
187 memset(stat, 0, sizeof(*stat));
188 stat->result_mask |= STATX_BASIC_STATS;
189 query_flags &= AT_STATX_SYNC_TYPE;
190
191 /* allow the fs to override these if it really wants to */
192 /* SB_NOATIME means filesystem supplies dummy atime value */
193 if (inode->i_sb->s_flags & SB_NOATIME)
194 stat->result_mask &= ~STATX_ATIME;
195
196 /*
197 * Note: If you add another clause to set an attribute flag, please
198 * update attributes_mask below.
199 */
200 if (IS_AUTOMOUNT(inode))
201 stat->attributes |= STATX_ATTR_AUTOMOUNT;
202
203 if (IS_DAX(inode))
204 stat->attributes |= STATX_ATTR_DAX;
205
206 stat->attributes_mask |= (STATX_ATTR_AUTOMOUNT |
207 STATX_ATTR_DAX);
208
209 idmap = mnt_idmap(path->mnt);
210 if (inode->i_op->getattr) {
211 int ret;
212
213 ret = inode->i_op->getattr(idmap, path, stat, request_mask,
214 query_flags);
215 if (ret)
216 return ret;
217 } else {
218 generic_fillattr(idmap, request_mask, inode, stat);
219 }
220
221 /*
222 * If this is a block device inode, override the filesystem attributes
223 * with the block device specific parameters that need to be obtained
224 * from the bdev backing inode.
225 */
226 if (S_ISBLK(stat->mode))
227 bdev_statx(path, stat, request_mask);
228
229 return 0;
230}
231EXPORT_SYMBOL(vfs_getattr_nosec);
232
233/*
234 * vfs_getattr - Get the enhanced basic attributes of a file
235 * @path: The file of interest
236 * @stat: Where to return the statistics
237 * @request_mask: STATX_xxx flags indicating what the caller wants
238 * @query_flags: Query mode (AT_STATX_SYNC_TYPE)
239 *
240 * Ask the filesystem for a file's attributes. The caller must indicate in
241 * request_mask and query_flags to indicate what they want.
242 *
243 * If the file is remote, the filesystem can be forced to update the attributes
244 * from the backing store by passing AT_STATX_FORCE_SYNC in query_flags or can
245 * suppress the update by passing AT_STATX_DONT_SYNC.
246 *
247 * Bits must have been set in request_mask to indicate which attributes the
248 * caller wants retrieving. Any such attribute not requested may be returned
249 * anyway, but the value may be approximate, and, if remote, may not have been
250 * synchronised with the server.
251 *
252 * 0 will be returned on success, and a -ve error code if unsuccessful.
253 */
254int vfs_getattr(const struct path *path, struct kstat *stat,
255 u32 request_mask, unsigned int query_flags)
256{
257 int retval;
258
259 retval = security_inode_getattr(path);
260 if (unlikely(retval))
261 return retval;
262 return vfs_getattr_nosec(path, stat, request_mask, query_flags);
263}
264EXPORT_SYMBOL(vfs_getattr);
265
266/**
267 * vfs_fstat - Get the basic attributes by file descriptor
268 * @fd: The file descriptor referring to the file of interest
269 * @stat: The result structure to fill in.
270 *
271 * This function is a wrapper around vfs_getattr(). The main difference is
272 * that it uses a file descriptor to determine the file location.
273 *
274 * 0 will be returned on success, and a -ve error code if unsuccessful.
275 */
276int vfs_fstat(int fd, struct kstat *stat)
277{
278 CLASS(fd_raw, f)(fd);
279 if (fd_empty(f))
280 return -EBADF;
281 return vfs_getattr(&fd_file(f)->f_path, stat, STATX_BASIC_STATS, 0);
282}
283
284static int statx_lookup_flags(int flags)
285{
286 int lookup_flags = 0;
287
288 if (!(flags & AT_SYMLINK_NOFOLLOW))
289 lookup_flags |= LOOKUP_FOLLOW;
290 if (!(flags & AT_NO_AUTOMOUNT))
291 lookup_flags |= LOOKUP_AUTOMOUNT;
292
293 return lookup_flags;
294}
295
296static int vfs_statx_path(const struct path *path, int flags, struct kstat *stat,
297 u32 request_mask)
298{
299 int error = vfs_getattr(path, stat, request_mask, flags);
300 if (error)
301 return error;
302
303 if (request_mask & STATX_MNT_ID_UNIQUE) {
304 stat->mnt_id = real_mount(path->mnt)->mnt_id_unique;
305 stat->result_mask |= STATX_MNT_ID_UNIQUE;
306 } else {
307 stat->mnt_id = real_mount(path->mnt)->mnt_id;
308 stat->result_mask |= STATX_MNT_ID;
309 }
310
311 if (path_mounted(path))
312 stat->attributes |= STATX_ATTR_MOUNT_ROOT;
313 stat->attributes_mask |= STATX_ATTR_MOUNT_ROOT;
314 return 0;
315}
316
317static int vfs_statx_fd(int fd, int flags, struct kstat *stat,
318 u32 request_mask)
319{
320 CLASS(fd_raw, f)(fd);
321 if (fd_empty(f))
322 return -EBADF;
323 return vfs_statx_path(&fd_file(f)->f_path, flags, stat, request_mask);
324}
325
326/**
327 * vfs_statx - Get basic and extra attributes by filename
328 * @dfd: A file descriptor representing the base dir for a relative filename
329 * @filename: The name of the file of interest
330 * @flags: Flags to control the query
331 * @stat: The result structure to fill in.
332 * @request_mask: STATX_xxx flags indicating what the caller wants
333 *
334 * This function is a wrapper around vfs_getattr(). The main difference is
335 * that it uses a filename and base directory to determine the file location.
336 * Additionally, the use of AT_SYMLINK_NOFOLLOW in flags will prevent a symlink
337 * at the given name from being referenced.
338 *
339 * 0 will be returned on success, and a -ve error code if unsuccessful.
340 */
341static int vfs_statx(int dfd, struct filename *filename, int flags,
342 struct kstat *stat, u32 request_mask)
343{
344 struct path path;
345 unsigned int lookup_flags = statx_lookup_flags(flags);
346 int error;
347
348 if (flags & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT | AT_EMPTY_PATH |
349 AT_STATX_SYNC_TYPE))
350 return -EINVAL;
351
352retry:
353 error = filename_lookup(dfd, filename, lookup_flags, &path, NULL);
354 if (error)
355 return error;
356 error = vfs_statx_path(&path, flags, stat, request_mask);
357 path_put(&path);
358 if (retry_estale(error, lookup_flags)) {
359 lookup_flags |= LOOKUP_REVAL;
360 goto retry;
361 }
362 return error;
363}
364
365int vfs_fstatat(int dfd, const char __user *filename,
366 struct kstat *stat, int flags)
367{
368 CLASS(filename_maybe_null, name)(filename, flags);
369
370 if (!name && dfd >= 0)
371 return vfs_fstat(dfd, stat);
372
373 return vfs_statx(dfd, name, flags | AT_NO_AUTOMOUNT,
374 stat, STATX_BASIC_STATS);
375}
376
377#ifdef __ARCH_WANT_OLD_STAT
378
379/*
380 * For backward compatibility? Maybe this should be moved
381 * into arch/i386 instead?
382 */
383static int cp_old_stat(struct kstat *stat, struct __old_kernel_stat __user * statbuf)
384{
385 static int warncount = 5;
386 struct __old_kernel_stat tmp;
387
388 if (warncount > 0) {
389 warncount--;
390 printk(KERN_WARNING "VFS: Warning: %s using old stat() call. Recompile your binary.\n",
391 current->comm);
392 } else if (warncount < 0) {
393 /* it's laughable, but... */
394 warncount = 0;
395 }
396
397 memset(&tmp, 0, sizeof(struct __old_kernel_stat));
398 tmp.st_dev = old_encode_dev(stat->dev);
399 tmp.st_ino = stat->ino;
400 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
401 return -EOVERFLOW;
402 tmp.st_mode = stat->mode;
403 tmp.st_nlink = stat->nlink;
404 if (tmp.st_nlink != stat->nlink)
405 return -EOVERFLOW;
406 SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
407 SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
408 tmp.st_rdev = old_encode_dev(stat->rdev);
409#if BITS_PER_LONG == 32
410 if (stat->size > MAX_NON_LFS)
411 return -EOVERFLOW;
412#endif
413 tmp.st_size = stat->size;
414 tmp.st_atime = stat->atime.tv_sec;
415 tmp.st_mtime = stat->mtime.tv_sec;
416 tmp.st_ctime = stat->ctime.tv_sec;
417 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
418}
419
420SYSCALL_DEFINE2(stat, const char __user *, filename,
421 struct __old_kernel_stat __user *, statbuf)
422{
423 struct kstat stat;
424 int error;
425
426 error = vfs_stat(filename, &stat);
427 if (unlikely(error))
428 return error;
429
430 return cp_old_stat(&stat, statbuf);
431}
432
433SYSCALL_DEFINE2(lstat, const char __user *, filename,
434 struct __old_kernel_stat __user *, statbuf)
435{
436 struct kstat stat;
437 int error;
438
439 error = vfs_lstat(filename, &stat);
440 if (unlikely(error))
441 return error;
442
443 return cp_old_stat(&stat, statbuf);
444}
445
446SYSCALL_DEFINE2(fstat, unsigned int, fd, struct __old_kernel_stat __user *, statbuf)
447{
448 struct kstat stat;
449 int error;
450
451 error = vfs_fstat(fd, &stat);
452 if (unlikely(error))
453 return error;
454
455 return cp_old_stat(&stat, statbuf);
456}
457
458#endif /* __ARCH_WANT_OLD_STAT */
459
460#ifdef __ARCH_WANT_NEW_STAT
461
462#ifndef INIT_STRUCT_STAT_PADDING
463# define INIT_STRUCT_STAT_PADDING(st) memset(&st, 0, sizeof(st))
464#endif
465
466static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf)
467{
468 struct stat tmp;
469
470 if (sizeof(tmp.st_dev) < 4 && !old_valid_dev(stat->dev))
471 return -EOVERFLOW;
472 if (sizeof(tmp.st_rdev) < 4 && !old_valid_dev(stat->rdev))
473 return -EOVERFLOW;
474#if BITS_PER_LONG == 32
475 if (stat->size > MAX_NON_LFS)
476 return -EOVERFLOW;
477#endif
478
479 INIT_STRUCT_STAT_PADDING(tmp);
480 tmp.st_dev = new_encode_dev(stat->dev);
481 tmp.st_ino = stat->ino;
482 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
483 return -EOVERFLOW;
484 tmp.st_mode = stat->mode;
485 tmp.st_nlink = stat->nlink;
486 if (tmp.st_nlink != stat->nlink)
487 return -EOVERFLOW;
488 SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
489 SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
490 tmp.st_rdev = new_encode_dev(stat->rdev);
491 tmp.st_size = stat->size;
492 tmp.st_atime = stat->atime.tv_sec;
493 tmp.st_mtime = stat->mtime.tv_sec;
494 tmp.st_ctime = stat->ctime.tv_sec;
495#ifdef STAT_HAVE_NSEC
496 tmp.st_atime_nsec = stat->atime.tv_nsec;
497 tmp.st_mtime_nsec = stat->mtime.tv_nsec;
498 tmp.st_ctime_nsec = stat->ctime.tv_nsec;
499#endif
500 tmp.st_blocks = stat->blocks;
501 tmp.st_blksize = stat->blksize;
502 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
503}
504
505SYSCALL_DEFINE2(newstat, const char __user *, filename,
506 struct stat __user *, statbuf)
507{
508 struct kstat stat;
509 int error;
510
511 error = vfs_stat(filename, &stat);
512 if (unlikely(error))
513 return error;
514
515 return cp_new_stat(&stat, statbuf);
516}
517
518SYSCALL_DEFINE2(newlstat, const char __user *, filename,
519 struct stat __user *, statbuf)
520{
521 struct kstat stat;
522 int error;
523
524 error = vfs_lstat(filename, &stat);
525 if (unlikely(error))
526 return error;
527
528 return cp_new_stat(&stat, statbuf);
529}
530
531#if !defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_SYS_NEWFSTATAT)
532SYSCALL_DEFINE4(newfstatat, int, dfd, const char __user *, filename,
533 struct stat __user *, statbuf, int, flag)
534{
535 struct kstat stat;
536 int error;
537
538 error = vfs_fstatat(dfd, filename, &stat, flag);
539 if (unlikely(error))
540 return error;
541
542 return cp_new_stat(&stat, statbuf);
543}
544#endif
545
546SYSCALL_DEFINE2(newfstat, unsigned int, fd, struct stat __user *, statbuf)
547{
548 struct kstat stat;
549 int error;
550
551 error = vfs_fstat(fd, &stat);
552 if (unlikely(error))
553 return error;
554
555 return cp_new_stat(&stat, statbuf);
556}
557#endif
558
559static int do_readlinkat(int dfd, const char __user *pathname,
560 char __user *buf, int bufsiz)
561{
562 struct path path;
563 int error;
564 unsigned int lookup_flags = 0;
565
566 if (bufsiz <= 0)
567 return -EINVAL;
568
569 CLASS(filename_flags, name)(pathname, LOOKUP_EMPTY);
570retry:
571 error = filename_lookup(dfd, name, lookup_flags, &path, NULL);
572 if (unlikely(error))
573 return error;
574
575 /*
576 * AFS mountpoints allow readlink(2) but are not symlinks
577 */
578 if (d_is_symlink(path.dentry) ||
579 d_backing_inode(path.dentry)->i_op->readlink) {
580 error = security_inode_readlink(path.dentry);
581 if (!error) {
582 touch_atime(&path);
583 error = vfs_readlink(path.dentry, buf, bufsiz);
584 }
585 } else {
586 error = (name->name[0] == '\0') ? -ENOENT : -EINVAL;
587 }
588 path_put(&path);
589 if (retry_estale(error, lookup_flags)) {
590 lookup_flags |= LOOKUP_REVAL;
591 goto retry;
592 }
593 return error;
594}
595
596SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname,
597 char __user *, buf, int, bufsiz)
598{
599 return do_readlinkat(dfd, pathname, buf, bufsiz);
600}
601
602SYSCALL_DEFINE3(readlink, const char __user *, path, char __user *, buf,
603 int, bufsiz)
604{
605 return do_readlinkat(AT_FDCWD, path, buf, bufsiz);
606}
607
608
609/* ---------- LFS-64 ----------- */
610#if defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_COMPAT_STAT64)
611
612#ifndef INIT_STRUCT_STAT64_PADDING
613# define INIT_STRUCT_STAT64_PADDING(st) memset(&st, 0, sizeof(st))
614#endif
615
616static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf)
617{
618 struct stat64 tmp;
619
620 INIT_STRUCT_STAT64_PADDING(tmp);
621#ifdef CONFIG_MIPS
622 /* mips has weird padding, so we don't get 64 bits there */
623 tmp.st_dev = new_encode_dev(stat->dev);
624 tmp.st_rdev = new_encode_dev(stat->rdev);
625#else
626 tmp.st_dev = huge_encode_dev(stat->dev);
627 tmp.st_rdev = huge_encode_dev(stat->rdev);
628#endif
629 tmp.st_ino = stat->ino;
630 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
631 return -EOVERFLOW;
632#ifdef STAT64_HAS_BROKEN_ST_INO
633 tmp.__st_ino = stat->ino;
634#endif
635 tmp.st_mode = stat->mode;
636 tmp.st_nlink = stat->nlink;
637 tmp.st_uid = from_kuid_munged(current_user_ns(), stat->uid);
638 tmp.st_gid = from_kgid_munged(current_user_ns(), stat->gid);
639 tmp.st_atime = stat->atime.tv_sec;
640 tmp.st_atime_nsec = stat->atime.tv_nsec;
641 tmp.st_mtime = stat->mtime.tv_sec;
642 tmp.st_mtime_nsec = stat->mtime.tv_nsec;
643 tmp.st_ctime = stat->ctime.tv_sec;
644 tmp.st_ctime_nsec = stat->ctime.tv_nsec;
645 tmp.st_size = stat->size;
646 tmp.st_blocks = stat->blocks;
647 tmp.st_blksize = stat->blksize;
648 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
649}
650
651SYSCALL_DEFINE2(stat64, const char __user *, filename,
652 struct stat64 __user *, statbuf)
653{
654 struct kstat stat;
655 int error = vfs_stat(filename, &stat);
656
657 if (!error)
658 error = cp_new_stat64(&stat, statbuf);
659
660 return error;
661}
662
663SYSCALL_DEFINE2(lstat64, const char __user *, filename,
664 struct stat64 __user *, statbuf)
665{
666 struct kstat stat;
667 int error = vfs_lstat(filename, &stat);
668
669 if (!error)
670 error = cp_new_stat64(&stat, statbuf);
671
672 return error;
673}
674
675SYSCALL_DEFINE2(fstat64, unsigned long, fd, struct stat64 __user *, statbuf)
676{
677 struct kstat stat;
678 int error = vfs_fstat(fd, &stat);
679
680 if (!error)
681 error = cp_new_stat64(&stat, statbuf);
682
683 return error;
684}
685
686SYSCALL_DEFINE4(fstatat64, int, dfd, const char __user *, filename,
687 struct stat64 __user *, statbuf, int, flag)
688{
689 struct kstat stat;
690 int error;
691
692 error = vfs_fstatat(dfd, filename, &stat, flag);
693 if (error)
694 return error;
695 return cp_new_stat64(&stat, statbuf);
696}
697#endif /* __ARCH_WANT_STAT64 || __ARCH_WANT_COMPAT_STAT64 */
698
699static noinline_for_stack int
700cp_statx(const struct kstat *stat, struct statx __user *buffer)
701{
702 struct statx tmp;
703
704 memset(&tmp, 0, sizeof(tmp));
705
706 /* STATX_CHANGE_COOKIE is kernel-only for now */
707 tmp.stx_mask = stat->result_mask & ~STATX_CHANGE_COOKIE;
708 tmp.stx_blksize = stat->blksize;
709 /* STATX_ATTR_CHANGE_MONOTONIC is kernel-only for now */
710 tmp.stx_attributes = stat->attributes & ~STATX_ATTR_CHANGE_MONOTONIC;
711 tmp.stx_nlink = stat->nlink;
712 tmp.stx_uid = from_kuid_munged(current_user_ns(), stat->uid);
713 tmp.stx_gid = from_kgid_munged(current_user_ns(), stat->gid);
714 tmp.stx_mode = stat->mode;
715 tmp.stx_ino = stat->ino;
716 tmp.stx_size = stat->size;
717 tmp.stx_blocks = stat->blocks;
718 tmp.stx_attributes_mask = stat->attributes_mask;
719 tmp.stx_atime.tv_sec = stat->atime.tv_sec;
720 tmp.stx_atime.tv_nsec = stat->atime.tv_nsec;
721 tmp.stx_btime.tv_sec = stat->btime.tv_sec;
722 tmp.stx_btime.tv_nsec = stat->btime.tv_nsec;
723 tmp.stx_ctime.tv_sec = stat->ctime.tv_sec;
724 tmp.stx_ctime.tv_nsec = stat->ctime.tv_nsec;
725 tmp.stx_mtime.tv_sec = stat->mtime.tv_sec;
726 tmp.stx_mtime.tv_nsec = stat->mtime.tv_nsec;
727 tmp.stx_rdev_major = MAJOR(stat->rdev);
728 tmp.stx_rdev_minor = MINOR(stat->rdev);
729 tmp.stx_dev_major = MAJOR(stat->dev);
730 tmp.stx_dev_minor = MINOR(stat->dev);
731 tmp.stx_mnt_id = stat->mnt_id;
732 tmp.stx_dio_mem_align = stat->dio_mem_align;
733 tmp.stx_dio_offset_align = stat->dio_offset_align;
734 tmp.stx_dio_read_offset_align = stat->dio_read_offset_align;
735 tmp.stx_subvol = stat->subvol;
736 tmp.stx_atomic_write_unit_min = stat->atomic_write_unit_min;
737 tmp.stx_atomic_write_unit_max = stat->atomic_write_unit_max;
738 tmp.stx_atomic_write_segments_max = stat->atomic_write_segments_max;
739 tmp.stx_atomic_write_unit_max_opt = stat->atomic_write_unit_max_opt;
740
741 return copy_to_user(buffer, &tmp, sizeof(tmp)) ? -EFAULT : 0;
742}
743
744int do_statx(int dfd, struct filename *filename, unsigned int flags,
745 unsigned int mask, struct statx __user *buffer)
746{
747 struct kstat stat;
748 int error;
749
750 if (mask & STATX__RESERVED)
751 return -EINVAL;
752 if ((flags & AT_STATX_SYNC_TYPE) == AT_STATX_SYNC_TYPE)
753 return -EINVAL;
754
755 /*
756 * STATX_CHANGE_COOKIE is kernel-only for now. Ignore requests
757 * from userland.
758 */
759 mask &= ~STATX_CHANGE_COOKIE;
760
761 error = vfs_statx(dfd, filename, flags, &stat, mask);
762 if (error)
763 return error;
764
765 return cp_statx(&stat, buffer);
766}
767
768int do_statx_fd(int fd, unsigned int flags, unsigned int mask,
769 struct statx __user *buffer)
770{
771 struct kstat stat;
772 int error;
773
774 if (mask & STATX__RESERVED)
775 return -EINVAL;
776 if ((flags & AT_STATX_SYNC_TYPE) == AT_STATX_SYNC_TYPE)
777 return -EINVAL;
778
779 /*
780 * STATX_CHANGE_COOKIE is kernel-only for now. Ignore requests
781 * from userland.
782 */
783 mask &= ~STATX_CHANGE_COOKIE;
784
785 error = vfs_statx_fd(fd, flags, &stat, mask);
786 if (error)
787 return error;
788
789 return cp_statx(&stat, buffer);
790}
791
792/**
793 * sys_statx - System call to get enhanced stats
794 * @dfd: Base directory to pathwalk from *or* fd to stat.
795 * @filename: File to stat or either NULL or "" with AT_EMPTY_PATH
796 * @flags: AT_* flags to control pathwalk.
797 * @mask: Parts of statx struct actually required.
798 * @buffer: Result buffer.
799 *
800 * Note that fstat() can be emulated by setting dfd to the fd of interest,
801 * supplying "" (or preferably NULL) as the filename and setting AT_EMPTY_PATH
802 * in the flags.
803 */
804SYSCALL_DEFINE5(statx,
805 int, dfd, const char __user *, filename, unsigned, flags,
806 unsigned int, mask,
807 struct statx __user *, buffer)
808{
809 CLASS(filename_maybe_null, name)(filename, flags);
810
811 if (!name && dfd >= 0)
812 return do_statx_fd(dfd, flags & ~AT_NO_AUTOMOUNT, mask, buffer);
813
814 return do_statx(dfd, name, flags, mask, buffer);
815}
816
817#if defined(CONFIG_COMPAT) && defined(__ARCH_WANT_COMPAT_STAT)
818static int cp_compat_stat(struct kstat *stat, struct compat_stat __user *ubuf)
819{
820 struct compat_stat tmp;
821
822 if (sizeof(tmp.st_dev) < 4 && !old_valid_dev(stat->dev))
823 return -EOVERFLOW;
824 if (sizeof(tmp.st_rdev) < 4 && !old_valid_dev(stat->rdev))
825 return -EOVERFLOW;
826
827 memset(&tmp, 0, sizeof(tmp));
828 tmp.st_dev = new_encode_dev(stat->dev);
829 tmp.st_ino = stat->ino;
830 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
831 return -EOVERFLOW;
832 tmp.st_mode = stat->mode;
833 tmp.st_nlink = stat->nlink;
834 if (tmp.st_nlink != stat->nlink)
835 return -EOVERFLOW;
836 SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
837 SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
838 tmp.st_rdev = new_encode_dev(stat->rdev);
839 if ((u64) stat->size > MAX_NON_LFS)
840 return -EOVERFLOW;
841 tmp.st_size = stat->size;
842 tmp.st_atime = stat->atime.tv_sec;
843 tmp.st_atime_nsec = stat->atime.tv_nsec;
844 tmp.st_mtime = stat->mtime.tv_sec;
845 tmp.st_mtime_nsec = stat->mtime.tv_nsec;
846 tmp.st_ctime = stat->ctime.tv_sec;
847 tmp.st_ctime_nsec = stat->ctime.tv_nsec;
848 tmp.st_blocks = stat->blocks;
849 tmp.st_blksize = stat->blksize;
850 return copy_to_user(ubuf, &tmp, sizeof(tmp)) ? -EFAULT : 0;
851}
852
853COMPAT_SYSCALL_DEFINE2(newstat, const char __user *, filename,
854 struct compat_stat __user *, statbuf)
855{
856 struct kstat stat;
857 int error;
858
859 error = vfs_stat(filename, &stat);
860 if (error)
861 return error;
862 return cp_compat_stat(&stat, statbuf);
863}
864
865COMPAT_SYSCALL_DEFINE2(newlstat, const char __user *, filename,
866 struct compat_stat __user *, statbuf)
867{
868 struct kstat stat;
869 int error;
870
871 error = vfs_lstat(filename, &stat);
872 if (error)
873 return error;
874 return cp_compat_stat(&stat, statbuf);
875}
876
877#ifndef __ARCH_WANT_STAT64
878COMPAT_SYSCALL_DEFINE4(newfstatat, unsigned int, dfd,
879 const char __user *, filename,
880 struct compat_stat __user *, statbuf, int, flag)
881{
882 struct kstat stat;
883 int error;
884
885 error = vfs_fstatat(dfd, filename, &stat, flag);
886 if (error)
887 return error;
888 return cp_compat_stat(&stat, statbuf);
889}
890#endif
891
892COMPAT_SYSCALL_DEFINE2(newfstat, unsigned int, fd,
893 struct compat_stat __user *, statbuf)
894{
895 struct kstat stat;
896 int error = vfs_fstat(fd, &stat);
897
898 if (!error)
899 error = cp_compat_stat(&stat, statbuf);
900 return error;
901}
902#endif
903
904/* Caller is here responsible for sufficient locking (ie. inode->i_lock) */
905void __inode_add_bytes(struct inode *inode, loff_t bytes)
906{
907 inode->i_blocks += bytes >> 9;
908 bytes &= 511;
909 inode->i_bytes += bytes;
910 if (inode->i_bytes >= 512) {
911 inode->i_blocks++;
912 inode->i_bytes -= 512;
913 }
914}
915EXPORT_SYMBOL(__inode_add_bytes);
916
917void inode_add_bytes(struct inode *inode, loff_t bytes)
918{
919 spin_lock(&inode->i_lock);
920 __inode_add_bytes(inode, bytes);
921 spin_unlock(&inode->i_lock);
922}
923
924EXPORT_SYMBOL(inode_add_bytes);
925
926void __inode_sub_bytes(struct inode *inode, loff_t bytes)
927{
928 inode->i_blocks -= bytes >> 9;
929 bytes &= 511;
930 if (inode->i_bytes < bytes) {
931 inode->i_blocks--;
932 inode->i_bytes += 512;
933 }
934 inode->i_bytes -= bytes;
935}
936
937EXPORT_SYMBOL(__inode_sub_bytes);
938
939void inode_sub_bytes(struct inode *inode, loff_t bytes)
940{
941 spin_lock(&inode->i_lock);
942 __inode_sub_bytes(inode, bytes);
943 spin_unlock(&inode->i_lock);
944}
945
946EXPORT_SYMBOL(inode_sub_bytes);
947
948loff_t inode_get_bytes(struct inode *inode)
949{
950 loff_t ret;
951
952 spin_lock(&inode->i_lock);
953 ret = __inode_get_bytes(inode);
954 spin_unlock(&inode->i_lock);
955 return ret;
956}
957
958EXPORT_SYMBOL(inode_get_bytes);
959
960void inode_set_bytes(struct inode *inode, loff_t bytes)
961{
962 /* Caller is here responsible for sufficient locking
963 * (ie. inode->i_lock) */
964 inode->i_blocks = bytes >> 9;
965 inode->i_bytes = bytes & 511;
966}
967
968EXPORT_SYMBOL(inode_set_bytes);