arch: Add SYSVIPC_COMPAT for all architectures
[linux-block.git] / fs / stat.c
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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/fs/stat.c
4 *
5 * Copyright (C) 1991, 1992 Linus Torvalds
6 */
7
8#include <linux/export.h>
9#include <linux/mm.h>
10#include <linux/errno.h>
11#include <linux/file.h>
12#include <linux/highuid.h>
13#include <linux/fs.h>
14#include <linux/namei.h>
15#include <linux/security.h>
16#include <linux/cred.h>
17#include <linux/syscalls.h>
18#include <linux/pagemap.h>
19#include <linux/compat.h>
20
21#include <linux/uaccess.h>
22#include <asm/unistd.h>
23
24#include "internal.h"
25#include "mount.h"
26
27/**
28 * generic_fillattr - Fill in the basic attributes from the inode struct
29 * @mnt_userns: user namespace of the mount the inode was found from
30 * @inode: Inode to use as the source
31 * @stat: Where to fill in the attributes
32 *
33 * Fill in the basic attributes in the kstat structure from data that's to be
34 * found on the VFS inode structure. This is the default if no getattr inode
35 * operation is supplied.
36 *
37 * If the inode has been found through an idmapped mount the user namespace of
38 * the vfsmount must be passed through @mnt_userns. This function will then
39 * take care to map the inode according to @mnt_userns before filling in the
40 * uid and gid filds. On non-idmapped mounts or if permission checking is to be
41 * performed on the raw inode simply passs init_user_ns.
42 */
43void generic_fillattr(struct user_namespace *mnt_userns, struct inode *inode,
44 struct kstat *stat)
45{
46 stat->dev = inode->i_sb->s_dev;
47 stat->ino = inode->i_ino;
48 stat->mode = inode->i_mode;
49 stat->nlink = inode->i_nlink;
50 stat->uid = i_uid_into_mnt(mnt_userns, inode);
51 stat->gid = i_gid_into_mnt(mnt_userns, inode);
52 stat->rdev = inode->i_rdev;
53 stat->size = i_size_read(inode);
54 stat->atime = inode->i_atime;
55 stat->mtime = inode->i_mtime;
56 stat->ctime = inode->i_ctime;
57 stat->blksize = i_blocksize(inode);
58 stat->blocks = inode->i_blocks;
59}
60EXPORT_SYMBOL(generic_fillattr);
61
62/**
63 * generic_fill_statx_attr - Fill in the statx attributes from the inode flags
64 * @inode: Inode to use as the source
65 * @stat: Where to fill in the attribute flags
66 *
67 * Fill in the STATX_ATTR_* flags in the kstat structure for properties of the
68 * inode that are published on i_flags and enforced by the VFS.
69 */
70void generic_fill_statx_attr(struct inode *inode, struct kstat *stat)
71{
72 if (inode->i_flags & S_IMMUTABLE)
73 stat->attributes |= STATX_ATTR_IMMUTABLE;
74 if (inode->i_flags & S_APPEND)
75 stat->attributes |= STATX_ATTR_APPEND;
76 stat->attributes_mask |= KSTAT_ATTR_VFS_FLAGS;
77}
78EXPORT_SYMBOL(generic_fill_statx_attr);
79
80/**
81 * vfs_getattr_nosec - getattr without security checks
82 * @path: file to get attributes from
83 * @stat: structure to return attributes in
84 * @request_mask: STATX_xxx flags indicating what the caller wants
85 * @query_flags: Query mode (AT_STATX_SYNC_TYPE)
86 *
87 * Get attributes without calling security_inode_getattr.
88 *
89 * Currently the only caller other than vfs_getattr is internal to the
90 * filehandle lookup code, which uses only the inode number and returns no
91 * attributes to any user. Any other code probably wants vfs_getattr.
92 */
93int vfs_getattr_nosec(const struct path *path, struct kstat *stat,
94 u32 request_mask, unsigned int query_flags)
95{
96 struct user_namespace *mnt_userns;
97 struct inode *inode = d_backing_inode(path->dentry);
98
99 memset(stat, 0, sizeof(*stat));
100 stat->result_mask |= STATX_BASIC_STATS;
101 query_flags &= AT_STATX_SYNC_TYPE;
102
103 /* allow the fs to override these if it really wants to */
104 /* SB_NOATIME means filesystem supplies dummy atime value */
105 if (inode->i_sb->s_flags & SB_NOATIME)
106 stat->result_mask &= ~STATX_ATIME;
107
108 /*
109 * Note: If you add another clause to set an attribute flag, please
110 * update attributes_mask below.
111 */
112 if (IS_AUTOMOUNT(inode))
113 stat->attributes |= STATX_ATTR_AUTOMOUNT;
114
115 if (IS_DAX(inode))
116 stat->attributes |= STATX_ATTR_DAX;
117
118 stat->attributes_mask |= (STATX_ATTR_AUTOMOUNT |
119 STATX_ATTR_DAX);
120
121 mnt_userns = mnt_user_ns(path->mnt);
122 if (inode->i_op->getattr)
123 return inode->i_op->getattr(mnt_userns, path, stat,
124 request_mask, query_flags);
125
126 generic_fillattr(mnt_userns, inode, stat);
127 return 0;
128}
129EXPORT_SYMBOL(vfs_getattr_nosec);
130
131/*
132 * vfs_getattr - Get the enhanced basic attributes of a file
133 * @path: The file of interest
134 * @stat: Where to return the statistics
135 * @request_mask: STATX_xxx flags indicating what the caller wants
136 * @query_flags: Query mode (AT_STATX_SYNC_TYPE)
137 *
138 * Ask the filesystem for a file's attributes. The caller must indicate in
139 * request_mask and query_flags to indicate what they want.
140 *
141 * If the file is remote, the filesystem can be forced to update the attributes
142 * from the backing store by passing AT_STATX_FORCE_SYNC in query_flags or can
143 * suppress the update by passing AT_STATX_DONT_SYNC.
144 *
145 * Bits must have been set in request_mask to indicate which attributes the
146 * caller wants retrieving. Any such attribute not requested may be returned
147 * anyway, but the value may be approximate, and, if remote, may not have been
148 * synchronised with the server.
149 *
150 * 0 will be returned on success, and a -ve error code if unsuccessful.
151 */
152int vfs_getattr(const struct path *path, struct kstat *stat,
153 u32 request_mask, unsigned int query_flags)
154{
155 int retval;
156
157 retval = security_inode_getattr(path);
158 if (retval)
159 return retval;
160 return vfs_getattr_nosec(path, stat, request_mask, query_flags);
161}
162EXPORT_SYMBOL(vfs_getattr);
163
164/**
165 * vfs_fstat - Get the basic attributes by file descriptor
166 * @fd: The file descriptor referring to the file of interest
167 * @stat: The result structure to fill in.
168 *
169 * This function is a wrapper around vfs_getattr(). The main difference is
170 * that it uses a file descriptor to determine the file location.
171 *
172 * 0 will be returned on success, and a -ve error code if unsuccessful.
173 */
174int vfs_fstat(int fd, struct kstat *stat)
175{
176 struct fd f;
177 int error;
178
179 f = fdget_raw(fd);
180 if (!f.file)
181 return -EBADF;
182 error = vfs_getattr(&f.file->f_path, stat, STATX_BASIC_STATS, 0);
183 fdput(f);
184 return error;
185}
186
187int getname_statx_lookup_flags(int flags)
188{
189 int lookup_flags = 0;
190
191 if (!(flags & AT_SYMLINK_NOFOLLOW))
192 lookup_flags |= LOOKUP_FOLLOW;
193 if (!(flags & AT_NO_AUTOMOUNT))
194 lookup_flags |= LOOKUP_AUTOMOUNT;
195 if (flags & AT_EMPTY_PATH)
196 lookup_flags |= LOOKUP_EMPTY;
197
198 return lookup_flags;
199}
200
201/**
202 * vfs_statx - Get basic and extra attributes by filename
203 * @dfd: A file descriptor representing the base dir for a relative filename
204 * @filename: The name of the file of interest
205 * @flags: Flags to control the query
206 * @stat: The result structure to fill in.
207 * @request_mask: STATX_xxx flags indicating what the caller wants
208 *
209 * This function is a wrapper around vfs_getattr(). The main difference is
210 * that it uses a filename and base directory to determine the file location.
211 * Additionally, the use of AT_SYMLINK_NOFOLLOW in flags will prevent a symlink
212 * at the given name from being referenced.
213 *
214 * 0 will be returned on success, and a -ve error code if unsuccessful.
215 */
216static int vfs_statx(int dfd, struct filename *filename, int flags,
217 struct kstat *stat, u32 request_mask)
218{
219 struct path path;
220 unsigned int lookup_flags = getname_statx_lookup_flags(flags);
221 int error;
222
223 if (flags & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT | AT_EMPTY_PATH |
224 AT_STATX_SYNC_TYPE))
225 return -EINVAL;
226
227retry:
228 error = filename_lookup(dfd, filename, lookup_flags, &path, NULL);
229 if (error)
230 goto out;
231
232 error = vfs_getattr(&path, stat, request_mask, flags);
233 stat->mnt_id = real_mount(path.mnt)->mnt_id;
234 stat->result_mask |= STATX_MNT_ID;
235 if (path.mnt->mnt_root == path.dentry)
236 stat->attributes |= STATX_ATTR_MOUNT_ROOT;
237 stat->attributes_mask |= STATX_ATTR_MOUNT_ROOT;
238 path_put(&path);
239 if (retry_estale(error, lookup_flags)) {
240 lookup_flags |= LOOKUP_REVAL;
241 goto retry;
242 }
243out:
244 return error;
245}
246
247int vfs_fstatat(int dfd, const char __user *filename,
248 struct kstat *stat, int flags)
249{
250 int ret;
251 int statx_flags = flags | AT_NO_AUTOMOUNT;
252 struct filename *name;
253
254 name = getname_flags(filename, getname_statx_lookup_flags(statx_flags), NULL);
255 ret = vfs_statx(dfd, name, statx_flags, stat, STATX_BASIC_STATS);
256 putname(name);
257
258 return ret;
259}
260
261#ifdef __ARCH_WANT_OLD_STAT
262
263/*
264 * For backward compatibility? Maybe this should be moved
265 * into arch/i386 instead?
266 */
267static int cp_old_stat(struct kstat *stat, struct __old_kernel_stat __user * statbuf)
268{
269 static int warncount = 5;
270 struct __old_kernel_stat tmp;
271
272 if (warncount > 0) {
273 warncount--;
274 printk(KERN_WARNING "VFS: Warning: %s using old stat() call. Recompile your binary.\n",
275 current->comm);
276 } else if (warncount < 0) {
277 /* it's laughable, but... */
278 warncount = 0;
279 }
280
281 memset(&tmp, 0, sizeof(struct __old_kernel_stat));
282 tmp.st_dev = old_encode_dev(stat->dev);
283 tmp.st_ino = stat->ino;
284 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
285 return -EOVERFLOW;
286 tmp.st_mode = stat->mode;
287 tmp.st_nlink = stat->nlink;
288 if (tmp.st_nlink != stat->nlink)
289 return -EOVERFLOW;
290 SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
291 SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
292 tmp.st_rdev = old_encode_dev(stat->rdev);
293#if BITS_PER_LONG == 32
294 if (stat->size > MAX_NON_LFS)
295 return -EOVERFLOW;
296#endif
297 tmp.st_size = stat->size;
298 tmp.st_atime = stat->atime.tv_sec;
299 tmp.st_mtime = stat->mtime.tv_sec;
300 tmp.st_ctime = stat->ctime.tv_sec;
301 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
302}
303
304SYSCALL_DEFINE2(stat, const char __user *, filename,
305 struct __old_kernel_stat __user *, statbuf)
306{
307 struct kstat stat;
308 int error;
309
310 error = vfs_stat(filename, &stat);
311 if (error)
312 return error;
313
314 return cp_old_stat(&stat, statbuf);
315}
316
317SYSCALL_DEFINE2(lstat, const char __user *, filename,
318 struct __old_kernel_stat __user *, statbuf)
319{
320 struct kstat stat;
321 int error;
322
323 error = vfs_lstat(filename, &stat);
324 if (error)
325 return error;
326
327 return cp_old_stat(&stat, statbuf);
328}
329
330SYSCALL_DEFINE2(fstat, unsigned int, fd, struct __old_kernel_stat __user *, statbuf)
331{
332 struct kstat stat;
333 int error = vfs_fstat(fd, &stat);
334
335 if (!error)
336 error = cp_old_stat(&stat, statbuf);
337
338 return error;
339}
340
341#endif /* __ARCH_WANT_OLD_STAT */
342
343#ifdef __ARCH_WANT_NEW_STAT
344
345#if BITS_PER_LONG == 32
346# define choose_32_64(a,b) a
347#else
348# define choose_32_64(a,b) b
349#endif
350
351#define valid_dev(x) choose_32_64(old_valid_dev(x),true)
352#define encode_dev(x) choose_32_64(old_encode_dev,new_encode_dev)(x)
353
354#ifndef INIT_STRUCT_STAT_PADDING
355# define INIT_STRUCT_STAT_PADDING(st) memset(&st, 0, sizeof(st))
356#endif
357
358static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf)
359{
360 struct stat tmp;
361
362 if (!valid_dev(stat->dev) || !valid_dev(stat->rdev))
363 return -EOVERFLOW;
364#if BITS_PER_LONG == 32
365 if (stat->size > MAX_NON_LFS)
366 return -EOVERFLOW;
367#endif
368
369 INIT_STRUCT_STAT_PADDING(tmp);
370 tmp.st_dev = encode_dev(stat->dev);
371 tmp.st_ino = stat->ino;
372 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
373 return -EOVERFLOW;
374 tmp.st_mode = stat->mode;
375 tmp.st_nlink = stat->nlink;
376 if (tmp.st_nlink != stat->nlink)
377 return -EOVERFLOW;
378 SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
379 SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
380 tmp.st_rdev = encode_dev(stat->rdev);
381 tmp.st_size = stat->size;
382 tmp.st_atime = stat->atime.tv_sec;
383 tmp.st_mtime = stat->mtime.tv_sec;
384 tmp.st_ctime = stat->ctime.tv_sec;
385#ifdef STAT_HAVE_NSEC
386 tmp.st_atime_nsec = stat->atime.tv_nsec;
387 tmp.st_mtime_nsec = stat->mtime.tv_nsec;
388 tmp.st_ctime_nsec = stat->ctime.tv_nsec;
389#endif
390 tmp.st_blocks = stat->blocks;
391 tmp.st_blksize = stat->blksize;
392 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
393}
394
395SYSCALL_DEFINE2(newstat, const char __user *, filename,
396 struct stat __user *, statbuf)
397{
398 struct kstat stat;
399 int error = vfs_stat(filename, &stat);
400
401 if (error)
402 return error;
403 return cp_new_stat(&stat, statbuf);
404}
405
406SYSCALL_DEFINE2(newlstat, const char __user *, filename,
407 struct stat __user *, statbuf)
408{
409 struct kstat stat;
410 int error;
411
412 error = vfs_lstat(filename, &stat);
413 if (error)
414 return error;
415
416 return cp_new_stat(&stat, statbuf);
417}
418
419#if !defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_SYS_NEWFSTATAT)
420SYSCALL_DEFINE4(newfstatat, int, dfd, const char __user *, filename,
421 struct stat __user *, statbuf, int, flag)
422{
423 struct kstat stat;
424 int error;
425
426 error = vfs_fstatat(dfd, filename, &stat, flag);
427 if (error)
428 return error;
429 return cp_new_stat(&stat, statbuf);
430}
431#endif
432
433SYSCALL_DEFINE2(newfstat, unsigned int, fd, struct stat __user *, statbuf)
434{
435 struct kstat stat;
436 int error = vfs_fstat(fd, &stat);
437
438 if (!error)
439 error = cp_new_stat(&stat, statbuf);
440
441 return error;
442}
443#endif
444
445static int do_readlinkat(int dfd, const char __user *pathname,
446 char __user *buf, int bufsiz)
447{
448 struct path path;
449 int error;
450 int empty = 0;
451 unsigned int lookup_flags = LOOKUP_EMPTY;
452
453 if (bufsiz <= 0)
454 return -EINVAL;
455
456retry:
457 error = user_path_at_empty(dfd, pathname, lookup_flags, &path, &empty);
458 if (!error) {
459 struct inode *inode = d_backing_inode(path.dentry);
460
461 error = empty ? -ENOENT : -EINVAL;
462 /*
463 * AFS mountpoints allow readlink(2) but are not symlinks
464 */
465 if (d_is_symlink(path.dentry) || inode->i_op->readlink) {
466 error = security_inode_readlink(path.dentry);
467 if (!error) {
468 touch_atime(&path);
469 error = vfs_readlink(path.dentry, buf, bufsiz);
470 }
471 }
472 path_put(&path);
473 if (retry_estale(error, lookup_flags)) {
474 lookup_flags |= LOOKUP_REVAL;
475 goto retry;
476 }
477 }
478 return error;
479}
480
481SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname,
482 char __user *, buf, int, bufsiz)
483{
484 return do_readlinkat(dfd, pathname, buf, bufsiz);
485}
486
487SYSCALL_DEFINE3(readlink, const char __user *, path, char __user *, buf,
488 int, bufsiz)
489{
490 return do_readlinkat(AT_FDCWD, path, buf, bufsiz);
491}
492
493
494/* ---------- LFS-64 ----------- */
495#if defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_COMPAT_STAT64)
496
497#ifndef INIT_STRUCT_STAT64_PADDING
498# define INIT_STRUCT_STAT64_PADDING(st) memset(&st, 0, sizeof(st))
499#endif
500
501static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf)
502{
503 struct stat64 tmp;
504
505 INIT_STRUCT_STAT64_PADDING(tmp);
506#ifdef CONFIG_MIPS
507 /* mips has weird padding, so we don't get 64 bits there */
508 tmp.st_dev = new_encode_dev(stat->dev);
509 tmp.st_rdev = new_encode_dev(stat->rdev);
510#else
511 tmp.st_dev = huge_encode_dev(stat->dev);
512 tmp.st_rdev = huge_encode_dev(stat->rdev);
513#endif
514 tmp.st_ino = stat->ino;
515 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
516 return -EOVERFLOW;
517#ifdef STAT64_HAS_BROKEN_ST_INO
518 tmp.__st_ino = stat->ino;
519#endif
520 tmp.st_mode = stat->mode;
521 tmp.st_nlink = stat->nlink;
522 tmp.st_uid = from_kuid_munged(current_user_ns(), stat->uid);
523 tmp.st_gid = from_kgid_munged(current_user_ns(), stat->gid);
524 tmp.st_atime = stat->atime.tv_sec;
525 tmp.st_atime_nsec = stat->atime.tv_nsec;
526 tmp.st_mtime = stat->mtime.tv_sec;
527 tmp.st_mtime_nsec = stat->mtime.tv_nsec;
528 tmp.st_ctime = stat->ctime.tv_sec;
529 tmp.st_ctime_nsec = stat->ctime.tv_nsec;
530 tmp.st_size = stat->size;
531 tmp.st_blocks = stat->blocks;
532 tmp.st_blksize = stat->blksize;
533 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
534}
535
536SYSCALL_DEFINE2(stat64, const char __user *, filename,
537 struct stat64 __user *, statbuf)
538{
539 struct kstat stat;
540 int error = vfs_stat(filename, &stat);
541
542 if (!error)
543 error = cp_new_stat64(&stat, statbuf);
544
545 return error;
546}
547
548SYSCALL_DEFINE2(lstat64, const char __user *, filename,
549 struct stat64 __user *, statbuf)
550{
551 struct kstat stat;
552 int error = vfs_lstat(filename, &stat);
553
554 if (!error)
555 error = cp_new_stat64(&stat, statbuf);
556
557 return error;
558}
559
560SYSCALL_DEFINE2(fstat64, unsigned long, fd, struct stat64 __user *, statbuf)
561{
562 struct kstat stat;
563 int error = vfs_fstat(fd, &stat);
564
565 if (!error)
566 error = cp_new_stat64(&stat, statbuf);
567
568 return error;
569}
570
571SYSCALL_DEFINE4(fstatat64, int, dfd, const char __user *, filename,
572 struct stat64 __user *, statbuf, int, flag)
573{
574 struct kstat stat;
575 int error;
576
577 error = vfs_fstatat(dfd, filename, &stat, flag);
578 if (error)
579 return error;
580 return cp_new_stat64(&stat, statbuf);
581}
582#endif /* __ARCH_WANT_STAT64 || __ARCH_WANT_COMPAT_STAT64 */
583
584static noinline_for_stack int
585cp_statx(const struct kstat *stat, struct statx __user *buffer)
586{
587 struct statx tmp;
588
589 memset(&tmp, 0, sizeof(tmp));
590
591 tmp.stx_mask = stat->result_mask;
592 tmp.stx_blksize = stat->blksize;
593 tmp.stx_attributes = stat->attributes;
594 tmp.stx_nlink = stat->nlink;
595 tmp.stx_uid = from_kuid_munged(current_user_ns(), stat->uid);
596 tmp.stx_gid = from_kgid_munged(current_user_ns(), stat->gid);
597 tmp.stx_mode = stat->mode;
598 tmp.stx_ino = stat->ino;
599 tmp.stx_size = stat->size;
600 tmp.stx_blocks = stat->blocks;
601 tmp.stx_attributes_mask = stat->attributes_mask;
602 tmp.stx_atime.tv_sec = stat->atime.tv_sec;
603 tmp.stx_atime.tv_nsec = stat->atime.tv_nsec;
604 tmp.stx_btime.tv_sec = stat->btime.tv_sec;
605 tmp.stx_btime.tv_nsec = stat->btime.tv_nsec;
606 tmp.stx_ctime.tv_sec = stat->ctime.tv_sec;
607 tmp.stx_ctime.tv_nsec = stat->ctime.tv_nsec;
608 tmp.stx_mtime.tv_sec = stat->mtime.tv_sec;
609 tmp.stx_mtime.tv_nsec = stat->mtime.tv_nsec;
610 tmp.stx_rdev_major = MAJOR(stat->rdev);
611 tmp.stx_rdev_minor = MINOR(stat->rdev);
612 tmp.stx_dev_major = MAJOR(stat->dev);
613 tmp.stx_dev_minor = MINOR(stat->dev);
614 tmp.stx_mnt_id = stat->mnt_id;
615
616 return copy_to_user(buffer, &tmp, sizeof(tmp)) ? -EFAULT : 0;
617}
618
619int do_statx(int dfd, struct filename *filename, unsigned int flags,
620 unsigned int mask, struct statx __user *buffer)
621{
622 struct kstat stat;
623 int error;
624
625 if (mask & STATX__RESERVED)
626 return -EINVAL;
627 if ((flags & AT_STATX_SYNC_TYPE) == AT_STATX_SYNC_TYPE)
628 return -EINVAL;
629
630 error = vfs_statx(dfd, filename, flags, &stat, mask);
631 if (error)
632 return error;
633
634 return cp_statx(&stat, buffer);
635}
636
637/**
638 * sys_statx - System call to get enhanced stats
639 * @dfd: Base directory to pathwalk from *or* fd to stat.
640 * @filename: File to stat or "" with AT_EMPTY_PATH
641 * @flags: AT_* flags to control pathwalk.
642 * @mask: Parts of statx struct actually required.
643 * @buffer: Result buffer.
644 *
645 * Note that fstat() can be emulated by setting dfd to the fd of interest,
646 * supplying "" as the filename and setting AT_EMPTY_PATH in the flags.
647 */
648SYSCALL_DEFINE5(statx,
649 int, dfd, const char __user *, filename, unsigned, flags,
650 unsigned int, mask,
651 struct statx __user *, buffer)
652{
653 int ret;
654 struct filename *name;
655
656 name = getname_flags(filename, getname_statx_lookup_flags(flags), NULL);
657 ret = do_statx(dfd, name, flags, mask, buffer);
658 putname(name);
659
660 return ret;
661}
662
663#ifdef CONFIG_COMPAT
664static int cp_compat_stat(struct kstat *stat, struct compat_stat __user *ubuf)
665{
666 struct compat_stat tmp;
667
668 if (!old_valid_dev(stat->dev) || !old_valid_dev(stat->rdev))
669 return -EOVERFLOW;
670
671 memset(&tmp, 0, sizeof(tmp));
672 tmp.st_dev = old_encode_dev(stat->dev);
673 tmp.st_ino = stat->ino;
674 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
675 return -EOVERFLOW;
676 tmp.st_mode = stat->mode;
677 tmp.st_nlink = stat->nlink;
678 if (tmp.st_nlink != stat->nlink)
679 return -EOVERFLOW;
680 SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
681 SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
682 tmp.st_rdev = old_encode_dev(stat->rdev);
683 if ((u64) stat->size > MAX_NON_LFS)
684 return -EOVERFLOW;
685 tmp.st_size = stat->size;
686 tmp.st_atime = stat->atime.tv_sec;
687 tmp.st_atime_nsec = stat->atime.tv_nsec;
688 tmp.st_mtime = stat->mtime.tv_sec;
689 tmp.st_mtime_nsec = stat->mtime.tv_nsec;
690 tmp.st_ctime = stat->ctime.tv_sec;
691 tmp.st_ctime_nsec = stat->ctime.tv_nsec;
692 tmp.st_blocks = stat->blocks;
693 tmp.st_blksize = stat->blksize;
694 return copy_to_user(ubuf, &tmp, sizeof(tmp)) ? -EFAULT : 0;
695}
696
697COMPAT_SYSCALL_DEFINE2(newstat, const char __user *, filename,
698 struct compat_stat __user *, statbuf)
699{
700 struct kstat stat;
701 int error;
702
703 error = vfs_stat(filename, &stat);
704 if (error)
705 return error;
706 return cp_compat_stat(&stat, statbuf);
707}
708
709COMPAT_SYSCALL_DEFINE2(newlstat, const char __user *, filename,
710 struct compat_stat __user *, statbuf)
711{
712 struct kstat stat;
713 int error;
714
715 error = vfs_lstat(filename, &stat);
716 if (error)
717 return error;
718 return cp_compat_stat(&stat, statbuf);
719}
720
721#ifndef __ARCH_WANT_STAT64
722COMPAT_SYSCALL_DEFINE4(newfstatat, unsigned int, dfd,
723 const char __user *, filename,
724 struct compat_stat __user *, statbuf, int, flag)
725{
726 struct kstat stat;
727 int error;
728
729 error = vfs_fstatat(dfd, filename, &stat, flag);
730 if (error)
731 return error;
732 return cp_compat_stat(&stat, statbuf);
733}
734#endif
735
736COMPAT_SYSCALL_DEFINE2(newfstat, unsigned int, fd,
737 struct compat_stat __user *, statbuf)
738{
739 struct kstat stat;
740 int error = vfs_fstat(fd, &stat);
741
742 if (!error)
743 error = cp_compat_stat(&stat, statbuf);
744 return error;
745}
746#endif
747
748/* Caller is here responsible for sufficient locking (ie. inode->i_lock) */
749void __inode_add_bytes(struct inode *inode, loff_t bytes)
750{
751 inode->i_blocks += bytes >> 9;
752 bytes &= 511;
753 inode->i_bytes += bytes;
754 if (inode->i_bytes >= 512) {
755 inode->i_blocks++;
756 inode->i_bytes -= 512;
757 }
758}
759EXPORT_SYMBOL(__inode_add_bytes);
760
761void inode_add_bytes(struct inode *inode, loff_t bytes)
762{
763 spin_lock(&inode->i_lock);
764 __inode_add_bytes(inode, bytes);
765 spin_unlock(&inode->i_lock);
766}
767
768EXPORT_SYMBOL(inode_add_bytes);
769
770void __inode_sub_bytes(struct inode *inode, loff_t bytes)
771{
772 inode->i_blocks -= bytes >> 9;
773 bytes &= 511;
774 if (inode->i_bytes < bytes) {
775 inode->i_blocks--;
776 inode->i_bytes += 512;
777 }
778 inode->i_bytes -= bytes;
779}
780
781EXPORT_SYMBOL(__inode_sub_bytes);
782
783void inode_sub_bytes(struct inode *inode, loff_t bytes)
784{
785 spin_lock(&inode->i_lock);
786 __inode_sub_bytes(inode, bytes);
787 spin_unlock(&inode->i_lock);
788}
789
790EXPORT_SYMBOL(inode_sub_bytes);
791
792loff_t inode_get_bytes(struct inode *inode)
793{
794 loff_t ret;
795
796 spin_lock(&inode->i_lock);
797 ret = __inode_get_bytes(inode);
798 spin_unlock(&inode->i_lock);
799 return ret;
800}
801
802EXPORT_SYMBOL(inode_get_bytes);
803
804void inode_set_bytes(struct inode *inode, loff_t bytes)
805{
806 /* Caller is here responsible for sufficient locking
807 * (ie. inode->i_lock) */
808 inode->i_blocks = bytes >> 9;
809 inode->i_bytes = bytes & 511;
810}
811
812EXPORT_SYMBOL(inode_set_bytes);