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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_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(const 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 const 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 if (IS_VERITY(inode))
207 stat->attributes |= STATX_ATTR_VERITY;
208
209 stat->attributes_mask |= (STATX_ATTR_AUTOMOUNT |
210 STATX_ATTR_DAX |
211 STATX_ATTR_VERITY);
212
213 idmap = mnt_idmap(path->mnt);
214 if (inode->i_op->getattr) {
215 int ret;
216
217 ret = inode->i_op->getattr(idmap, path, stat, request_mask,
218 query_flags);
219 if (ret)
220 return ret;
221 } else {
222 generic_fillattr(idmap, request_mask, inode, stat);
223 }
224
225 /*
226 * If this is a block device inode, override the filesystem attributes
227 * with the block device specific parameters that need to be obtained
228 * from the bdev backing inode.
229 */
230 if (S_ISBLK(stat->mode))
231 bdev_statx(path, stat, request_mask);
232
233 return 0;
234}
235EXPORT_SYMBOL(vfs_getattr_nosec);
236
237/*
238 * vfs_getattr - Get the enhanced basic attributes of a file
239 * @path: The file of interest
240 * @stat: Where to return the statistics
241 * @request_mask: STATX_xxx flags indicating what the caller wants
242 * @query_flags: Query mode (AT_STATX_SYNC_TYPE)
243 *
244 * Ask the filesystem for a file's attributes. The caller must indicate in
245 * request_mask and query_flags to indicate what they want.
246 *
247 * If the file is remote, the filesystem can be forced to update the attributes
248 * from the backing store by passing AT_STATX_FORCE_SYNC in query_flags or can
249 * suppress the update by passing AT_STATX_DONT_SYNC.
250 *
251 * Bits must have been set in request_mask to indicate which attributes the
252 * caller wants retrieving. Any such attribute not requested may be returned
253 * anyway, but the value may be approximate, and, if remote, may not have been
254 * synchronised with the server.
255 *
256 * 0 will be returned on success, and a -ve error code if unsuccessful.
257 */
258int vfs_getattr(const struct path *path, struct kstat *stat,
259 u32 request_mask, unsigned int query_flags)
260{
261 int retval;
262
263 retval = security_inode_getattr(path);
264 if (unlikely(retval))
265 return retval;
266 return vfs_getattr_nosec(path, stat, request_mask, query_flags);
267}
268EXPORT_SYMBOL(vfs_getattr);
269
270/**
271 * vfs_fstat - Get the basic attributes by file descriptor
272 * @fd: The file descriptor referring to the file of interest
273 * @stat: The result structure to fill in.
274 *
275 * This function is a wrapper around vfs_getattr(). The main difference is
276 * that it uses a file descriptor to determine the file location.
277 *
278 * 0 will be returned on success, and a -ve error code if unsuccessful.
279 */
280int vfs_fstat(int fd, struct kstat *stat)
281{
282 CLASS(fd_raw, f)(fd);
283 if (fd_empty(f))
284 return -EBADF;
285 return vfs_getattr(&fd_file(f)->f_path, stat, STATX_BASIC_STATS, 0);
286}
287
288static int statx_lookup_flags(int flags)
289{
290 int lookup_flags = 0;
291
292 if (!(flags & AT_SYMLINK_NOFOLLOW))
293 lookup_flags |= LOOKUP_FOLLOW;
294 if (!(flags & AT_NO_AUTOMOUNT))
295 lookup_flags |= LOOKUP_AUTOMOUNT;
296
297 return lookup_flags;
298}
299
300static int vfs_statx_path(const struct path *path, int flags, struct kstat *stat,
301 u32 request_mask)
302{
303 int error = vfs_getattr(path, stat, request_mask, flags);
304 if (error)
305 return error;
306
307 if (request_mask & STATX_MNT_ID_UNIQUE) {
308 stat->mnt_id = real_mount(path->mnt)->mnt_id_unique;
309 stat->result_mask |= STATX_MNT_ID_UNIQUE;
310 } else {
311 stat->mnt_id = real_mount(path->mnt)->mnt_id;
312 stat->result_mask |= STATX_MNT_ID;
313 }
314
315 if (path_mounted(path))
316 stat->attributes |= STATX_ATTR_MOUNT_ROOT;
317 stat->attributes_mask |= STATX_ATTR_MOUNT_ROOT;
318 return 0;
319}
320
321static int vfs_statx_fd(int fd, int flags, struct kstat *stat,
322 u32 request_mask)
323{
324 CLASS(fd_raw, f)(fd);
325 if (fd_empty(f))
326 return -EBADF;
327 return vfs_statx_path(&fd_file(f)->f_path, flags, stat, request_mask);
328}
329
330/**
331 * vfs_statx - Get basic and extra attributes by filename
332 * @dfd: A file descriptor representing the base dir for a relative filename
333 * @filename: The name of the file of interest
334 * @flags: Flags to control the query
335 * @stat: The result structure to fill in.
336 * @request_mask: STATX_xxx flags indicating what the caller wants
337 *
338 * This function is a wrapper around vfs_getattr(). The main difference is
339 * that it uses a filename and base directory to determine the file location.
340 * Additionally, the use of AT_SYMLINK_NOFOLLOW in flags will prevent a symlink
341 * at the given name from being referenced.
342 *
343 * 0 will be returned on success, and a -ve error code if unsuccessful.
344 */
345static int vfs_statx(int dfd, struct filename *filename, int flags,
346 struct kstat *stat, u32 request_mask)
347{
348 struct path path;
349 unsigned int lookup_flags = statx_lookup_flags(flags);
350 int error;
351
352 if (flags & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT | AT_EMPTY_PATH |
353 AT_STATX_SYNC_TYPE))
354 return -EINVAL;
355
356retry:
357 error = filename_lookup(dfd, filename, lookup_flags, &path, NULL);
358 if (error)
359 return error;
360 error = vfs_statx_path(&path, flags, stat, request_mask);
361 path_put(&path);
362 if (retry_estale(error, lookup_flags)) {
363 lookup_flags |= LOOKUP_REVAL;
364 goto retry;
365 }
366 return error;
367}
368
369int vfs_fstatat(int dfd, const char __user *filename,
370 struct kstat *stat, int flags)
371{
372 CLASS(filename_maybe_null, name)(filename, flags);
373
374 if (!name && dfd >= 0)
375 return vfs_fstat(dfd, stat);
376
377 return vfs_statx(dfd, name, flags | AT_NO_AUTOMOUNT,
378 stat, STATX_BASIC_STATS);
379}
380
381#ifdef __ARCH_WANT_OLD_STAT
382
383/*
384 * For backward compatibility? Maybe this should be moved
385 * into arch/i386 instead?
386 */
387static int cp_old_stat(struct kstat *stat, struct __old_kernel_stat __user * statbuf)
388{
389 static int warncount = 5;
390 struct __old_kernel_stat tmp;
391
392 if (warncount > 0) {
393 warncount--;
394 printk(KERN_WARNING "VFS: Warning: %s using old stat() call. Recompile your binary.\n",
395 current->comm);
396 } else if (warncount < 0) {
397 /* it's laughable, but... */
398 warncount = 0;
399 }
400
401 memset(&tmp, 0, sizeof(struct __old_kernel_stat));
402 tmp.st_dev = old_encode_dev(stat->dev);
403 tmp.st_ino = stat->ino;
404 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
405 return -EOVERFLOW;
406 tmp.st_mode = stat->mode;
407 tmp.st_nlink = stat->nlink;
408 if (tmp.st_nlink != stat->nlink)
409 return -EOVERFLOW;
410 SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
411 SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
412 tmp.st_rdev = old_encode_dev(stat->rdev);
413#if BITS_PER_LONG == 32
414 if (stat->size > MAX_NON_LFS)
415 return -EOVERFLOW;
416#endif
417 tmp.st_size = stat->size;
418 tmp.st_atime = stat->atime.tv_sec;
419 tmp.st_mtime = stat->mtime.tv_sec;
420 tmp.st_ctime = stat->ctime.tv_sec;
421 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
422}
423
424SYSCALL_DEFINE2(stat, const char __user *, filename,
425 struct __old_kernel_stat __user *, statbuf)
426{
427 struct kstat stat;
428 int error;
429
430 error = vfs_stat(filename, &stat);
431 if (unlikely(error))
432 return error;
433
434 return cp_old_stat(&stat, statbuf);
435}
436
437SYSCALL_DEFINE2(lstat, const char __user *, filename,
438 struct __old_kernel_stat __user *, statbuf)
439{
440 struct kstat stat;
441 int error;
442
443 error = vfs_lstat(filename, &stat);
444 if (unlikely(error))
445 return error;
446
447 return cp_old_stat(&stat, statbuf);
448}
449
450SYSCALL_DEFINE2(fstat, unsigned int, fd, struct __old_kernel_stat __user *, statbuf)
451{
452 struct kstat stat;
453 int error;
454
455 error = vfs_fstat(fd, &stat);
456 if (unlikely(error))
457 return error;
458
459 return cp_old_stat(&stat, statbuf);
460}
461
462#endif /* __ARCH_WANT_OLD_STAT */
463
464#ifdef __ARCH_WANT_NEW_STAT
465
466#ifndef INIT_STRUCT_STAT_PADDING
467# define INIT_STRUCT_STAT_PADDING(st) memset(&st, 0, sizeof(st))
468#endif
469
470static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf)
471{
472 struct stat tmp;
473
474 if (sizeof(tmp.st_dev) < 4 && !old_valid_dev(stat->dev))
475 return -EOVERFLOW;
476 if (sizeof(tmp.st_rdev) < 4 && !old_valid_dev(stat->rdev))
477 return -EOVERFLOW;
478#if BITS_PER_LONG == 32
479 if (stat->size > MAX_NON_LFS)
480 return -EOVERFLOW;
481#endif
482
483 INIT_STRUCT_STAT_PADDING(tmp);
484 tmp.st_dev = new_encode_dev(stat->dev);
485 tmp.st_ino = stat->ino;
486 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
487 return -EOVERFLOW;
488 tmp.st_mode = stat->mode;
489 tmp.st_nlink = stat->nlink;
490 if (tmp.st_nlink != stat->nlink)
491 return -EOVERFLOW;
492 SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
493 SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
494 tmp.st_rdev = new_encode_dev(stat->rdev);
495 tmp.st_size = stat->size;
496 tmp.st_atime = stat->atime.tv_sec;
497 tmp.st_mtime = stat->mtime.tv_sec;
498 tmp.st_ctime = stat->ctime.tv_sec;
499#ifdef STAT_HAVE_NSEC
500 tmp.st_atime_nsec = stat->atime.tv_nsec;
501 tmp.st_mtime_nsec = stat->mtime.tv_nsec;
502 tmp.st_ctime_nsec = stat->ctime.tv_nsec;
503#endif
504 tmp.st_blocks = stat->blocks;
505 tmp.st_blksize = stat->blksize;
506 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
507}
508
509SYSCALL_DEFINE2(newstat, const char __user *, filename,
510 struct stat __user *, statbuf)
511{
512 struct kstat stat;
513 int error;
514
515 error = vfs_stat(filename, &stat);
516 if (unlikely(error))
517 return error;
518
519 return cp_new_stat(&stat, statbuf);
520}
521
522SYSCALL_DEFINE2(newlstat, const char __user *, filename,
523 struct stat __user *, statbuf)
524{
525 struct kstat stat;
526 int error;
527
528 error = vfs_lstat(filename, &stat);
529 if (unlikely(error))
530 return error;
531
532 return cp_new_stat(&stat, statbuf);
533}
534
535#if !defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_SYS_NEWFSTATAT)
536SYSCALL_DEFINE4(newfstatat, int, dfd, const char __user *, filename,
537 struct stat __user *, statbuf, int, flag)
538{
539 struct kstat stat;
540 int error;
541
542 error = vfs_fstatat(dfd, filename, &stat, flag);
543 if (unlikely(error))
544 return error;
545
546 return cp_new_stat(&stat, statbuf);
547}
548#endif
549
550SYSCALL_DEFINE2(newfstat, unsigned int, fd, struct stat __user *, statbuf)
551{
552 struct kstat stat;
553 int error;
554
555 error = vfs_fstat(fd, &stat);
556 if (unlikely(error))
557 return error;
558
559 return cp_new_stat(&stat, statbuf);
560}
561#endif
562
563static int do_readlinkat(int dfd, const char __user *pathname,
564 char __user *buf, int bufsiz)
565{
566 struct path path;
567 int error;
568 unsigned int lookup_flags = 0;
569
570 if (bufsiz <= 0)
571 return -EINVAL;
572
573 CLASS(filename_flags, name)(pathname, LOOKUP_EMPTY);
574retry:
575 error = filename_lookup(dfd, name, lookup_flags, &path, NULL);
576 if (unlikely(error))
577 return error;
578
579 /*
580 * AFS mountpoints allow readlink(2) but are not symlinks
581 */
582 if (d_is_symlink(path.dentry) ||
583 d_backing_inode(path.dentry)->i_op->readlink) {
584 error = security_inode_readlink(path.dentry);
585 if (!error) {
586 touch_atime(&path);
587 error = vfs_readlink(path.dentry, buf, bufsiz);
588 }
589 } else {
590 error = (name->name[0] == '\0') ? -ENOENT : -EINVAL;
591 }
592 path_put(&path);
593 if (retry_estale(error, lookup_flags)) {
594 lookup_flags |= LOOKUP_REVAL;
595 goto retry;
596 }
597 return error;
598}
599
600SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname,
601 char __user *, buf, int, bufsiz)
602{
603 return do_readlinkat(dfd, pathname, buf, bufsiz);
604}
605
606SYSCALL_DEFINE3(readlink, const char __user *, path, char __user *, buf,
607 int, bufsiz)
608{
609 return do_readlinkat(AT_FDCWD, path, buf, bufsiz);
610}
611
612
613/* ---------- LFS-64 ----------- */
614#if defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_COMPAT_STAT64)
615
616#ifndef INIT_STRUCT_STAT64_PADDING
617# define INIT_STRUCT_STAT64_PADDING(st) memset(&st, 0, sizeof(st))
618#endif
619
620static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf)
621{
622 struct stat64 tmp;
623
624 INIT_STRUCT_STAT64_PADDING(tmp);
625#ifdef CONFIG_MIPS
626 /* mips has weird padding, so we don't get 64 bits there */
627 tmp.st_dev = new_encode_dev(stat->dev);
628 tmp.st_rdev = new_encode_dev(stat->rdev);
629#else
630 tmp.st_dev = huge_encode_dev(stat->dev);
631 tmp.st_rdev = huge_encode_dev(stat->rdev);
632#endif
633 tmp.st_ino = stat->ino;
634 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
635 return -EOVERFLOW;
636#ifdef STAT64_HAS_BROKEN_ST_INO
637 tmp.__st_ino = stat->ino;
638#endif
639 tmp.st_mode = stat->mode;
640 tmp.st_nlink = stat->nlink;
641 tmp.st_uid = from_kuid_munged(current_user_ns(), stat->uid);
642 tmp.st_gid = from_kgid_munged(current_user_ns(), stat->gid);
643 tmp.st_atime = stat->atime.tv_sec;
644 tmp.st_atime_nsec = stat->atime.tv_nsec;
645 tmp.st_mtime = stat->mtime.tv_sec;
646 tmp.st_mtime_nsec = stat->mtime.tv_nsec;
647 tmp.st_ctime = stat->ctime.tv_sec;
648 tmp.st_ctime_nsec = stat->ctime.tv_nsec;
649 tmp.st_size = stat->size;
650 tmp.st_blocks = stat->blocks;
651 tmp.st_blksize = stat->blksize;
652 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
653}
654
655SYSCALL_DEFINE2(stat64, const char __user *, filename,
656 struct stat64 __user *, statbuf)
657{
658 struct kstat stat;
659 int error = vfs_stat(filename, &stat);
660
661 if (!error)
662 error = cp_new_stat64(&stat, statbuf);
663
664 return error;
665}
666
667SYSCALL_DEFINE2(lstat64, const char __user *, filename,
668 struct stat64 __user *, statbuf)
669{
670 struct kstat stat;
671 int error = vfs_lstat(filename, &stat);
672
673 if (!error)
674 error = cp_new_stat64(&stat, statbuf);
675
676 return error;
677}
678
679SYSCALL_DEFINE2(fstat64, unsigned long, fd, struct stat64 __user *, statbuf)
680{
681 struct kstat stat;
682 int error = vfs_fstat(fd, &stat);
683
684 if (!error)
685 error = cp_new_stat64(&stat, statbuf);
686
687 return error;
688}
689
690SYSCALL_DEFINE4(fstatat64, int, dfd, const char __user *, filename,
691 struct stat64 __user *, statbuf, int, flag)
692{
693 struct kstat stat;
694 int error;
695
696 error = vfs_fstatat(dfd, filename, &stat, flag);
697 if (error)
698 return error;
699 return cp_new_stat64(&stat, statbuf);
700}
701#endif /* __ARCH_WANT_STAT64 || __ARCH_WANT_COMPAT_STAT64 */
702
703static noinline_for_stack int
704cp_statx(const struct kstat *stat, struct statx __user *buffer)
705{
706 struct statx tmp;
707
708 memset(&tmp, 0, sizeof(tmp));
709
710 /* STATX_CHANGE_COOKIE is kernel-only for now */
711 tmp.stx_mask = stat->result_mask & ~STATX_CHANGE_COOKIE;
712 tmp.stx_blksize = stat->blksize;
713 /* STATX_ATTR_CHANGE_MONOTONIC is kernel-only for now */
714 tmp.stx_attributes = stat->attributes & ~STATX_ATTR_CHANGE_MONOTONIC;
715 tmp.stx_nlink = stat->nlink;
716 tmp.stx_uid = from_kuid_munged(current_user_ns(), stat->uid);
717 tmp.stx_gid = from_kgid_munged(current_user_ns(), stat->gid);
718 tmp.stx_mode = stat->mode;
719 tmp.stx_ino = stat->ino;
720 tmp.stx_size = stat->size;
721 tmp.stx_blocks = stat->blocks;
722 tmp.stx_attributes_mask = stat->attributes_mask;
723 tmp.stx_atime.tv_sec = stat->atime.tv_sec;
724 tmp.stx_atime.tv_nsec = stat->atime.tv_nsec;
725 tmp.stx_btime.tv_sec = stat->btime.tv_sec;
726 tmp.stx_btime.tv_nsec = stat->btime.tv_nsec;
727 tmp.stx_ctime.tv_sec = stat->ctime.tv_sec;
728 tmp.stx_ctime.tv_nsec = stat->ctime.tv_nsec;
729 tmp.stx_mtime.tv_sec = stat->mtime.tv_sec;
730 tmp.stx_mtime.tv_nsec = stat->mtime.tv_nsec;
731 tmp.stx_rdev_major = MAJOR(stat->rdev);
732 tmp.stx_rdev_minor = MINOR(stat->rdev);
733 tmp.stx_dev_major = MAJOR(stat->dev);
734 tmp.stx_dev_minor = MINOR(stat->dev);
735 tmp.stx_mnt_id = stat->mnt_id;
736 tmp.stx_dio_mem_align = stat->dio_mem_align;
737 tmp.stx_dio_offset_align = stat->dio_offset_align;
738 tmp.stx_dio_read_offset_align = stat->dio_read_offset_align;
739 tmp.stx_subvol = stat->subvol;
740 tmp.stx_atomic_write_unit_min = stat->atomic_write_unit_min;
741 tmp.stx_atomic_write_unit_max = stat->atomic_write_unit_max;
742 tmp.stx_atomic_write_segments_max = stat->atomic_write_segments_max;
743 tmp.stx_atomic_write_unit_max_opt = stat->atomic_write_unit_max_opt;
744
745 return copy_to_user(buffer, &tmp, sizeof(tmp)) ? -EFAULT : 0;
746}
747
748int do_statx(int dfd, struct filename *filename, unsigned int flags,
749 unsigned int mask, struct statx __user *buffer)
750{
751 struct kstat stat;
752 int error;
753
754 if (mask & STATX__RESERVED)
755 return -EINVAL;
756 if ((flags & AT_STATX_SYNC_TYPE) == AT_STATX_SYNC_TYPE)
757 return -EINVAL;
758
759 /*
760 * STATX_CHANGE_COOKIE is kernel-only for now. Ignore requests
761 * from userland.
762 */
763 mask &= ~STATX_CHANGE_COOKIE;
764
765 error = vfs_statx(dfd, filename, flags, &stat, mask);
766 if (error)
767 return error;
768
769 return cp_statx(&stat, buffer);
770}
771
772int do_statx_fd(int fd, unsigned int flags, unsigned int mask,
773 struct statx __user *buffer)
774{
775 struct kstat stat;
776 int error;
777
778 if (mask & STATX__RESERVED)
779 return -EINVAL;
780 if ((flags & AT_STATX_SYNC_TYPE) == AT_STATX_SYNC_TYPE)
781 return -EINVAL;
782
783 /*
784 * STATX_CHANGE_COOKIE is kernel-only for now. Ignore requests
785 * from userland.
786 */
787 mask &= ~STATX_CHANGE_COOKIE;
788
789 error = vfs_statx_fd(fd, flags, &stat, mask);
790 if (error)
791 return error;
792
793 return cp_statx(&stat, buffer);
794}
795
796/**
797 * sys_statx - System call to get enhanced stats
798 * @dfd: Base directory to pathwalk from *or* fd to stat.
799 * @filename: File to stat or either NULL or "" with AT_EMPTY_PATH
800 * @flags: AT_* flags to control pathwalk.
801 * @mask: Parts of statx struct actually required.
802 * @buffer: Result buffer.
803 *
804 * Note that fstat() can be emulated by setting dfd to the fd of interest,
805 * supplying "" (or preferably NULL) as the filename and setting AT_EMPTY_PATH
806 * in the flags.
807 */
808SYSCALL_DEFINE5(statx,
809 int, dfd, const char __user *, filename, unsigned, flags,
810 unsigned int, mask,
811 struct statx __user *, buffer)
812{
813 CLASS(filename_maybe_null, name)(filename, flags);
814
815 if (!name && dfd >= 0)
816 return do_statx_fd(dfd, flags & ~AT_NO_AUTOMOUNT, mask, buffer);
817
818 return do_statx(dfd, name, flags, mask, buffer);
819}
820
821#if defined(CONFIG_COMPAT) && defined(__ARCH_WANT_COMPAT_STAT)
822static int cp_compat_stat(struct kstat *stat, struct compat_stat __user *ubuf)
823{
824 struct compat_stat tmp;
825
826 if (sizeof(tmp.st_dev) < 4 && !old_valid_dev(stat->dev))
827 return -EOVERFLOW;
828 if (sizeof(tmp.st_rdev) < 4 && !old_valid_dev(stat->rdev))
829 return -EOVERFLOW;
830
831 memset(&tmp, 0, sizeof(tmp));
832 tmp.st_dev = new_encode_dev(stat->dev);
833 tmp.st_ino = stat->ino;
834 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
835 return -EOVERFLOW;
836 tmp.st_mode = stat->mode;
837 tmp.st_nlink = stat->nlink;
838 if (tmp.st_nlink != stat->nlink)
839 return -EOVERFLOW;
840 SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
841 SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
842 tmp.st_rdev = new_encode_dev(stat->rdev);
843 if ((u64) stat->size > MAX_NON_LFS)
844 return -EOVERFLOW;
845 tmp.st_size = stat->size;
846 tmp.st_atime = stat->atime.tv_sec;
847 tmp.st_atime_nsec = stat->atime.tv_nsec;
848 tmp.st_mtime = stat->mtime.tv_sec;
849 tmp.st_mtime_nsec = stat->mtime.tv_nsec;
850 tmp.st_ctime = stat->ctime.tv_sec;
851 tmp.st_ctime_nsec = stat->ctime.tv_nsec;
852 tmp.st_blocks = stat->blocks;
853 tmp.st_blksize = stat->blksize;
854 return copy_to_user(ubuf, &tmp, sizeof(tmp)) ? -EFAULT : 0;
855}
856
857COMPAT_SYSCALL_DEFINE2(newstat, const char __user *, filename,
858 struct compat_stat __user *, statbuf)
859{
860 struct kstat stat;
861 int error;
862
863 error = vfs_stat(filename, &stat);
864 if (error)
865 return error;
866 return cp_compat_stat(&stat, statbuf);
867}
868
869COMPAT_SYSCALL_DEFINE2(newlstat, const char __user *, filename,
870 struct compat_stat __user *, statbuf)
871{
872 struct kstat stat;
873 int error;
874
875 error = vfs_lstat(filename, &stat);
876 if (error)
877 return error;
878 return cp_compat_stat(&stat, statbuf);
879}
880
881#ifndef __ARCH_WANT_STAT64
882COMPAT_SYSCALL_DEFINE4(newfstatat, unsigned int, dfd,
883 const char __user *, filename,
884 struct compat_stat __user *, statbuf, int, flag)
885{
886 struct kstat stat;
887 int error;
888
889 error = vfs_fstatat(dfd, filename, &stat, flag);
890 if (error)
891 return error;
892 return cp_compat_stat(&stat, statbuf);
893}
894#endif
895
896COMPAT_SYSCALL_DEFINE2(newfstat, unsigned int, fd,
897 struct compat_stat __user *, statbuf)
898{
899 struct kstat stat;
900 int error = vfs_fstat(fd, &stat);
901
902 if (!error)
903 error = cp_compat_stat(&stat, statbuf);
904 return error;
905}
906#endif
907
908/* Caller is here responsible for sufficient locking (ie. inode->i_lock) */
909void __inode_add_bytes(struct inode *inode, loff_t bytes)
910{
911 inode->i_blocks += bytes >> 9;
912 bytes &= 511;
913 inode->i_bytes += bytes;
914 if (inode->i_bytes >= 512) {
915 inode->i_blocks++;
916 inode->i_bytes -= 512;
917 }
918}
919EXPORT_SYMBOL(__inode_add_bytes);
920
921void inode_add_bytes(struct inode *inode, loff_t bytes)
922{
923 spin_lock(&inode->i_lock);
924 __inode_add_bytes(inode, bytes);
925 spin_unlock(&inode->i_lock);
926}
927
928EXPORT_SYMBOL(inode_add_bytes);
929
930void __inode_sub_bytes(struct inode *inode, loff_t bytes)
931{
932 inode->i_blocks -= bytes >> 9;
933 bytes &= 511;
934 if (inode->i_bytes < bytes) {
935 inode->i_blocks--;
936 inode->i_bytes += 512;
937 }
938 inode->i_bytes -= bytes;
939}
940
941EXPORT_SYMBOL(__inode_sub_bytes);
942
943void inode_sub_bytes(struct inode *inode, loff_t bytes)
944{
945 spin_lock(&inode->i_lock);
946 __inode_sub_bytes(inode, bytes);
947 spin_unlock(&inode->i_lock);
948}
949
950EXPORT_SYMBOL(inode_sub_bytes);
951
952loff_t inode_get_bytes(struct inode *inode)
953{
954 loff_t ret;
955
956 spin_lock(&inode->i_lock);
957 ret = __inode_get_bytes(inode);
958 spin_unlock(&inode->i_lock);
959 return ret;
960}
961
962EXPORT_SYMBOL(inode_get_bytes);
963
964void inode_set_bytes(struct inode *inode, loff_t bytes)
965{
966 /* Caller is here responsible for sufficient locking
967 * (ie. inode->i_lock) */
968 inode->i_blocks = bytes >> 9;
969 inode->i_bytes = bytes & 511;
970}
971
972EXPORT_SYMBOL(inode_set_bytes);