]> git.proxmox.com Git - mirror_ubuntu-jammy-kernel.git/blob - fs/stat.c
dpaa2-switch: Fix memory leak in dpaa2_switch_acl_entry_add() and dpaa2_switch_acl_en...
[mirror_ubuntu-jammy-kernel.git] / fs / stat.c
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 */
43 void 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 }
60 EXPORT_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 */
70 void 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 }
78 EXPORT_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 */
93 int 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 }
129 EXPORT_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 */
152 int 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 }
162 EXPORT_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 */
174 int 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
187 /**
188 * vfs_statx - Get basic and extra attributes by filename
189 * @dfd: A file descriptor representing the base dir for a relative filename
190 * @filename: The name of the file of interest
191 * @flags: Flags to control the query
192 * @stat: The result structure to fill in.
193 * @request_mask: STATX_xxx flags indicating what the caller wants
194 *
195 * This function is a wrapper around vfs_getattr(). The main difference is
196 * that it uses a filename and base directory to determine the file location.
197 * Additionally, the use of AT_SYMLINK_NOFOLLOW in flags will prevent a symlink
198 * at the given name from being referenced.
199 *
200 * 0 will be returned on success, and a -ve error code if unsuccessful.
201 */
202 static int vfs_statx(int dfd, const char __user *filename, int flags,
203 struct kstat *stat, u32 request_mask)
204 {
205 struct path path;
206 unsigned lookup_flags = 0;
207 int error;
208
209 if (flags & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT | AT_EMPTY_PATH |
210 AT_STATX_SYNC_TYPE))
211 return -EINVAL;
212
213 if (!(flags & AT_SYMLINK_NOFOLLOW))
214 lookup_flags |= LOOKUP_FOLLOW;
215 if (!(flags & AT_NO_AUTOMOUNT))
216 lookup_flags |= LOOKUP_AUTOMOUNT;
217 if (flags & AT_EMPTY_PATH)
218 lookup_flags |= LOOKUP_EMPTY;
219
220 retry:
221 error = user_path_at(dfd, filename, lookup_flags, &path);
222 if (error)
223 goto out;
224
225 error = vfs_getattr(&path, stat, request_mask, flags);
226 stat->mnt_id = real_mount(path.mnt)->mnt_id;
227 stat->result_mask |= STATX_MNT_ID;
228 if (path.mnt->mnt_root == path.dentry)
229 stat->attributes |= STATX_ATTR_MOUNT_ROOT;
230 stat->attributes_mask |= STATX_ATTR_MOUNT_ROOT;
231 path_put(&path);
232 if (retry_estale(error, lookup_flags)) {
233 lookup_flags |= LOOKUP_REVAL;
234 goto retry;
235 }
236 out:
237 return error;
238 }
239
240 int vfs_fstatat(int dfd, const char __user *filename,
241 struct kstat *stat, int flags)
242 {
243 return vfs_statx(dfd, filename, flags | AT_NO_AUTOMOUNT,
244 stat, STATX_BASIC_STATS);
245 }
246
247 #ifdef __ARCH_WANT_OLD_STAT
248
249 /*
250 * For backward compatibility? Maybe this should be moved
251 * into arch/i386 instead?
252 */
253 static int cp_old_stat(struct kstat *stat, struct __old_kernel_stat __user * statbuf)
254 {
255 static int warncount = 5;
256 struct __old_kernel_stat tmp;
257
258 if (warncount > 0) {
259 warncount--;
260 printk(KERN_WARNING "VFS: Warning: %s using old stat() call. Recompile your binary.\n",
261 current->comm);
262 } else if (warncount < 0) {
263 /* it's laughable, but... */
264 warncount = 0;
265 }
266
267 memset(&tmp, 0, sizeof(struct __old_kernel_stat));
268 tmp.st_dev = old_encode_dev(stat->dev);
269 tmp.st_ino = stat->ino;
270 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
271 return -EOVERFLOW;
272 tmp.st_mode = stat->mode;
273 tmp.st_nlink = stat->nlink;
274 if (tmp.st_nlink != stat->nlink)
275 return -EOVERFLOW;
276 SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
277 SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
278 tmp.st_rdev = old_encode_dev(stat->rdev);
279 #if BITS_PER_LONG == 32
280 if (stat->size > MAX_NON_LFS)
281 return -EOVERFLOW;
282 #endif
283 tmp.st_size = stat->size;
284 tmp.st_atime = stat->atime.tv_sec;
285 tmp.st_mtime = stat->mtime.tv_sec;
286 tmp.st_ctime = stat->ctime.tv_sec;
287 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
288 }
289
290 SYSCALL_DEFINE2(stat, const char __user *, filename,
291 struct __old_kernel_stat __user *, statbuf)
292 {
293 struct kstat stat;
294 int error;
295
296 error = vfs_stat(filename, &stat);
297 if (error)
298 return error;
299
300 return cp_old_stat(&stat, statbuf);
301 }
302
303 SYSCALL_DEFINE2(lstat, const char __user *, filename,
304 struct __old_kernel_stat __user *, statbuf)
305 {
306 struct kstat stat;
307 int error;
308
309 error = vfs_lstat(filename, &stat);
310 if (error)
311 return error;
312
313 return cp_old_stat(&stat, statbuf);
314 }
315
316 SYSCALL_DEFINE2(fstat, unsigned int, fd, struct __old_kernel_stat __user *, statbuf)
317 {
318 struct kstat stat;
319 int error = vfs_fstat(fd, &stat);
320
321 if (!error)
322 error = cp_old_stat(&stat, statbuf);
323
324 return error;
325 }
326
327 #endif /* __ARCH_WANT_OLD_STAT */
328
329 #ifdef __ARCH_WANT_NEW_STAT
330
331 #if BITS_PER_LONG == 32
332 # define choose_32_64(a,b) a
333 #else
334 # define choose_32_64(a,b) b
335 #endif
336
337 #ifndef INIT_STRUCT_STAT_PADDING
338 # define INIT_STRUCT_STAT_PADDING(st) memset(&st, 0, sizeof(st))
339 #endif
340
341 static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf)
342 {
343 struct stat tmp;
344
345 if (sizeof(tmp.st_dev) < 4 && !old_valid_dev(stat->dev))
346 return -EOVERFLOW;
347 if (sizeof(tmp.st_rdev) < 4 && !old_valid_dev(stat->rdev))
348 return -EOVERFLOW;
349 #if BITS_PER_LONG == 32
350 if (stat->size > MAX_NON_LFS)
351 return -EOVERFLOW;
352 #endif
353
354 INIT_STRUCT_STAT_PADDING(tmp);
355 tmp.st_dev = new_encode_dev(stat->dev);
356 tmp.st_ino = stat->ino;
357 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
358 return -EOVERFLOW;
359 tmp.st_mode = stat->mode;
360 tmp.st_nlink = stat->nlink;
361 if (tmp.st_nlink != stat->nlink)
362 return -EOVERFLOW;
363 SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
364 SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
365 tmp.st_rdev = new_encode_dev(stat->rdev);
366 tmp.st_size = stat->size;
367 tmp.st_atime = stat->atime.tv_sec;
368 tmp.st_mtime = stat->mtime.tv_sec;
369 tmp.st_ctime = stat->ctime.tv_sec;
370 #ifdef STAT_HAVE_NSEC
371 tmp.st_atime_nsec = stat->atime.tv_nsec;
372 tmp.st_mtime_nsec = stat->mtime.tv_nsec;
373 tmp.st_ctime_nsec = stat->ctime.tv_nsec;
374 #endif
375 tmp.st_blocks = stat->blocks;
376 tmp.st_blksize = stat->blksize;
377 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
378 }
379
380 SYSCALL_DEFINE2(newstat, const char __user *, filename,
381 struct stat __user *, statbuf)
382 {
383 struct kstat stat;
384 int error = vfs_stat(filename, &stat);
385
386 if (error)
387 return error;
388 return cp_new_stat(&stat, statbuf);
389 }
390
391 SYSCALL_DEFINE2(newlstat, const char __user *, filename,
392 struct stat __user *, statbuf)
393 {
394 struct kstat stat;
395 int error;
396
397 error = vfs_lstat(filename, &stat);
398 if (error)
399 return error;
400
401 return cp_new_stat(&stat, statbuf);
402 }
403
404 #if !defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_SYS_NEWFSTATAT)
405 SYSCALL_DEFINE4(newfstatat, int, dfd, const char __user *, filename,
406 struct stat __user *, statbuf, int, flag)
407 {
408 struct kstat stat;
409 int error;
410
411 error = vfs_fstatat(dfd, filename, &stat, flag);
412 if (error)
413 return error;
414 return cp_new_stat(&stat, statbuf);
415 }
416 #endif
417
418 SYSCALL_DEFINE2(newfstat, unsigned int, fd, struct stat __user *, statbuf)
419 {
420 struct kstat stat;
421 int error = vfs_fstat(fd, &stat);
422
423 if (!error)
424 error = cp_new_stat(&stat, statbuf);
425
426 return error;
427 }
428 #endif
429
430 static int do_readlinkat(int dfd, const char __user *pathname,
431 char __user *buf, int bufsiz)
432 {
433 struct path path;
434 int error;
435 int empty = 0;
436 unsigned int lookup_flags = LOOKUP_EMPTY;
437
438 if (bufsiz <= 0)
439 return -EINVAL;
440
441 retry:
442 error = user_path_at_empty(dfd, pathname, lookup_flags, &path, &empty);
443 if (!error) {
444 struct inode *inode = d_backing_inode(path.dentry);
445
446 error = empty ? -ENOENT : -EINVAL;
447 /*
448 * AFS mountpoints allow readlink(2) but are not symlinks
449 */
450 if (d_is_symlink(path.dentry) || inode->i_op->readlink) {
451 error = security_inode_readlink(path.dentry);
452 if (!error) {
453 touch_atime(&path);
454 error = vfs_readlink(path.dentry, buf, bufsiz);
455 }
456 }
457 path_put(&path);
458 if (retry_estale(error, lookup_flags)) {
459 lookup_flags |= LOOKUP_REVAL;
460 goto retry;
461 }
462 }
463 return error;
464 }
465
466 SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname,
467 char __user *, buf, int, bufsiz)
468 {
469 return do_readlinkat(dfd, pathname, buf, bufsiz);
470 }
471
472 SYSCALL_DEFINE3(readlink, const char __user *, path, char __user *, buf,
473 int, bufsiz)
474 {
475 return do_readlinkat(AT_FDCWD, path, buf, bufsiz);
476 }
477
478
479 /* ---------- LFS-64 ----------- */
480 #if defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_COMPAT_STAT64)
481
482 #ifndef INIT_STRUCT_STAT64_PADDING
483 # define INIT_STRUCT_STAT64_PADDING(st) memset(&st, 0, sizeof(st))
484 #endif
485
486 static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf)
487 {
488 struct stat64 tmp;
489
490 INIT_STRUCT_STAT64_PADDING(tmp);
491 #ifdef CONFIG_MIPS
492 /* mips has weird padding, so we don't get 64 bits there */
493 tmp.st_dev = new_encode_dev(stat->dev);
494 tmp.st_rdev = new_encode_dev(stat->rdev);
495 #else
496 tmp.st_dev = huge_encode_dev(stat->dev);
497 tmp.st_rdev = huge_encode_dev(stat->rdev);
498 #endif
499 tmp.st_ino = stat->ino;
500 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
501 return -EOVERFLOW;
502 #ifdef STAT64_HAS_BROKEN_ST_INO
503 tmp.__st_ino = stat->ino;
504 #endif
505 tmp.st_mode = stat->mode;
506 tmp.st_nlink = stat->nlink;
507 tmp.st_uid = from_kuid_munged(current_user_ns(), stat->uid);
508 tmp.st_gid = from_kgid_munged(current_user_ns(), stat->gid);
509 tmp.st_atime = stat->atime.tv_sec;
510 tmp.st_atime_nsec = stat->atime.tv_nsec;
511 tmp.st_mtime = stat->mtime.tv_sec;
512 tmp.st_mtime_nsec = stat->mtime.tv_nsec;
513 tmp.st_ctime = stat->ctime.tv_sec;
514 tmp.st_ctime_nsec = stat->ctime.tv_nsec;
515 tmp.st_size = stat->size;
516 tmp.st_blocks = stat->blocks;
517 tmp.st_blksize = stat->blksize;
518 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
519 }
520
521 SYSCALL_DEFINE2(stat64, const char __user *, filename,
522 struct stat64 __user *, statbuf)
523 {
524 struct kstat stat;
525 int error = vfs_stat(filename, &stat);
526
527 if (!error)
528 error = cp_new_stat64(&stat, statbuf);
529
530 return error;
531 }
532
533 SYSCALL_DEFINE2(lstat64, const char __user *, filename,
534 struct stat64 __user *, statbuf)
535 {
536 struct kstat stat;
537 int error = vfs_lstat(filename, &stat);
538
539 if (!error)
540 error = cp_new_stat64(&stat, statbuf);
541
542 return error;
543 }
544
545 SYSCALL_DEFINE2(fstat64, unsigned long, fd, struct stat64 __user *, statbuf)
546 {
547 struct kstat stat;
548 int error = vfs_fstat(fd, &stat);
549
550 if (!error)
551 error = cp_new_stat64(&stat, statbuf);
552
553 return error;
554 }
555
556 SYSCALL_DEFINE4(fstatat64, int, dfd, const char __user *, filename,
557 struct stat64 __user *, statbuf, int, flag)
558 {
559 struct kstat stat;
560 int error;
561
562 error = vfs_fstatat(dfd, filename, &stat, flag);
563 if (error)
564 return error;
565 return cp_new_stat64(&stat, statbuf);
566 }
567 #endif /* __ARCH_WANT_STAT64 || __ARCH_WANT_COMPAT_STAT64 */
568
569 static noinline_for_stack int
570 cp_statx(const struct kstat *stat, struct statx __user *buffer)
571 {
572 struct statx tmp;
573
574 memset(&tmp, 0, sizeof(tmp));
575
576 tmp.stx_mask = stat->result_mask;
577 tmp.stx_blksize = stat->blksize;
578 tmp.stx_attributes = stat->attributes;
579 tmp.stx_nlink = stat->nlink;
580 tmp.stx_uid = from_kuid_munged(current_user_ns(), stat->uid);
581 tmp.stx_gid = from_kgid_munged(current_user_ns(), stat->gid);
582 tmp.stx_mode = stat->mode;
583 tmp.stx_ino = stat->ino;
584 tmp.stx_size = stat->size;
585 tmp.stx_blocks = stat->blocks;
586 tmp.stx_attributes_mask = stat->attributes_mask;
587 tmp.stx_atime.tv_sec = stat->atime.tv_sec;
588 tmp.stx_atime.tv_nsec = stat->atime.tv_nsec;
589 tmp.stx_btime.tv_sec = stat->btime.tv_sec;
590 tmp.stx_btime.tv_nsec = stat->btime.tv_nsec;
591 tmp.stx_ctime.tv_sec = stat->ctime.tv_sec;
592 tmp.stx_ctime.tv_nsec = stat->ctime.tv_nsec;
593 tmp.stx_mtime.tv_sec = stat->mtime.tv_sec;
594 tmp.stx_mtime.tv_nsec = stat->mtime.tv_nsec;
595 tmp.stx_rdev_major = MAJOR(stat->rdev);
596 tmp.stx_rdev_minor = MINOR(stat->rdev);
597 tmp.stx_dev_major = MAJOR(stat->dev);
598 tmp.stx_dev_minor = MINOR(stat->dev);
599 tmp.stx_mnt_id = stat->mnt_id;
600
601 return copy_to_user(buffer, &tmp, sizeof(tmp)) ? -EFAULT : 0;
602 }
603
604 int do_statx(int dfd, const char __user *filename, unsigned flags,
605 unsigned int mask, struct statx __user *buffer)
606 {
607 struct kstat stat;
608 int error;
609
610 if (mask & STATX__RESERVED)
611 return -EINVAL;
612 if ((flags & AT_STATX_SYNC_TYPE) == AT_STATX_SYNC_TYPE)
613 return -EINVAL;
614
615 error = vfs_statx(dfd, filename, flags, &stat, mask);
616 if (error)
617 return error;
618
619 return cp_statx(&stat, buffer);
620 }
621
622 /**
623 * sys_statx - System call to get enhanced stats
624 * @dfd: Base directory to pathwalk from *or* fd to stat.
625 * @filename: File to stat or "" with AT_EMPTY_PATH
626 * @flags: AT_* flags to control pathwalk.
627 * @mask: Parts of statx struct actually required.
628 * @buffer: Result buffer.
629 *
630 * Note that fstat() can be emulated by setting dfd to the fd of interest,
631 * supplying "" as the filename and setting AT_EMPTY_PATH in the flags.
632 */
633 SYSCALL_DEFINE5(statx,
634 int, dfd, const char __user *, filename, unsigned, flags,
635 unsigned int, mask,
636 struct statx __user *, buffer)
637 {
638 return do_statx(dfd, filename, flags, mask, buffer);
639 }
640
641 #ifdef CONFIG_COMPAT
642 static int cp_compat_stat(struct kstat *stat, struct compat_stat __user *ubuf)
643 {
644 struct compat_stat tmp;
645
646 if (sizeof(tmp.st_dev) < 4 && !old_valid_dev(stat->dev))
647 return -EOVERFLOW;
648 if (sizeof(tmp.st_rdev) < 4 && !old_valid_dev(stat->rdev))
649 return -EOVERFLOW;
650
651 memset(&tmp, 0, sizeof(tmp));
652 tmp.st_dev = new_encode_dev(stat->dev);
653 tmp.st_ino = stat->ino;
654 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
655 return -EOVERFLOW;
656 tmp.st_mode = stat->mode;
657 tmp.st_nlink = stat->nlink;
658 if (tmp.st_nlink != stat->nlink)
659 return -EOVERFLOW;
660 SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
661 SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
662 tmp.st_rdev = new_encode_dev(stat->rdev);
663 if ((u64) stat->size > MAX_NON_LFS)
664 return -EOVERFLOW;
665 tmp.st_size = stat->size;
666 tmp.st_atime = stat->atime.tv_sec;
667 tmp.st_atime_nsec = stat->atime.tv_nsec;
668 tmp.st_mtime = stat->mtime.tv_sec;
669 tmp.st_mtime_nsec = stat->mtime.tv_nsec;
670 tmp.st_ctime = stat->ctime.tv_sec;
671 tmp.st_ctime_nsec = stat->ctime.tv_nsec;
672 tmp.st_blocks = stat->blocks;
673 tmp.st_blksize = stat->blksize;
674 return copy_to_user(ubuf, &tmp, sizeof(tmp)) ? -EFAULT : 0;
675 }
676
677 COMPAT_SYSCALL_DEFINE2(newstat, const char __user *, filename,
678 struct compat_stat __user *, statbuf)
679 {
680 struct kstat stat;
681 int error;
682
683 error = vfs_stat(filename, &stat);
684 if (error)
685 return error;
686 return cp_compat_stat(&stat, statbuf);
687 }
688
689 COMPAT_SYSCALL_DEFINE2(newlstat, const char __user *, filename,
690 struct compat_stat __user *, statbuf)
691 {
692 struct kstat stat;
693 int error;
694
695 error = vfs_lstat(filename, &stat);
696 if (error)
697 return error;
698 return cp_compat_stat(&stat, statbuf);
699 }
700
701 #ifndef __ARCH_WANT_STAT64
702 COMPAT_SYSCALL_DEFINE4(newfstatat, unsigned int, dfd,
703 const char __user *, filename,
704 struct compat_stat __user *, statbuf, int, flag)
705 {
706 struct kstat stat;
707 int error;
708
709 error = vfs_fstatat(dfd, filename, &stat, flag);
710 if (error)
711 return error;
712 return cp_compat_stat(&stat, statbuf);
713 }
714 #endif
715
716 COMPAT_SYSCALL_DEFINE2(newfstat, unsigned int, fd,
717 struct compat_stat __user *, statbuf)
718 {
719 struct kstat stat;
720 int error = vfs_fstat(fd, &stat);
721
722 if (!error)
723 error = cp_compat_stat(&stat, statbuf);
724 return error;
725 }
726 #endif
727
728 /* Caller is here responsible for sufficient locking (ie. inode->i_lock) */
729 void __inode_add_bytes(struct inode *inode, loff_t bytes)
730 {
731 inode->i_blocks += bytes >> 9;
732 bytes &= 511;
733 inode->i_bytes += bytes;
734 if (inode->i_bytes >= 512) {
735 inode->i_blocks++;
736 inode->i_bytes -= 512;
737 }
738 }
739 EXPORT_SYMBOL(__inode_add_bytes);
740
741 void inode_add_bytes(struct inode *inode, loff_t bytes)
742 {
743 spin_lock(&inode->i_lock);
744 __inode_add_bytes(inode, bytes);
745 spin_unlock(&inode->i_lock);
746 }
747
748 EXPORT_SYMBOL(inode_add_bytes);
749
750 void __inode_sub_bytes(struct inode *inode, loff_t bytes)
751 {
752 inode->i_blocks -= bytes >> 9;
753 bytes &= 511;
754 if (inode->i_bytes < bytes) {
755 inode->i_blocks--;
756 inode->i_bytes += 512;
757 }
758 inode->i_bytes -= bytes;
759 }
760
761 EXPORT_SYMBOL(__inode_sub_bytes);
762
763 void inode_sub_bytes(struct inode *inode, loff_t bytes)
764 {
765 spin_lock(&inode->i_lock);
766 __inode_sub_bytes(inode, bytes);
767 spin_unlock(&inode->i_lock);
768 }
769
770 EXPORT_SYMBOL(inode_sub_bytes);
771
772 loff_t inode_get_bytes(struct inode *inode)
773 {
774 loff_t ret;
775
776 spin_lock(&inode->i_lock);
777 ret = __inode_get_bytes(inode);
778 spin_unlock(&inode->i_lock);
779 return ret;
780 }
781
782 EXPORT_SYMBOL(inode_get_bytes);
783
784 void inode_set_bytes(struct inode *inode, loff_t bytes)
785 {
786 /* Caller is here responsible for sufficient locking
787 * (ie. inode->i_lock) */
788 inode->i_blocks = bytes >> 9;
789 inode->i_bytes = bytes & 511;
790 }
791
792 EXPORT_SYMBOL(inode_set_bytes);