1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * linux/fs/stat.c
4 *
5 * Copyright (C) 1991, 1992 Linus Torvalds
6 */
7
8 #include <linux/blkdev.h>
9 #include <linux/export.h>
10 #include <linux/mm.h>
11 #include <linux/errno.h>
12 #include <linux/file.h>
13 #include <linux/highuid.h>
14 #include <linux/fs.h>
15 #include <linux/namei.h>
16 #include <linux/security.h>
17 #include <linux/cred.h>
18 #include <linux/syscalls.h>
19 #include <linux/pagemap.h>
20 #include <linux/compat.h>
21 #include <linux/iversion.h>
22
23 #include <linux/uaccess.h>
24 #include <asm/unistd.h>
25
26 #include "internal.h"
27 #include "mount.h"
28
29 /**
30 * generic_fillattr - Fill in the basic attributes from the inode struct
31 * @idmap: idmap of the mount the inode was found from
32 * @request_mask: statx request_mask
33 * @inode: Inode to use as the source
34 * @stat: Where to fill in the attributes
35 *
36 * Fill in the basic attributes in the kstat structure from data that's to be
37 * found on the VFS inode structure. This is the default if no getattr inode
38 * operation is supplied.
39 *
40 * If the inode has been found through an idmapped mount the idmap of
41 * the vfsmount must be passed through @idmap. This function will then
42 * take care to map the inode according to @idmap before filling in the
43 * uid and gid filds. On non-idmapped mounts or if permission checking is to be
44 * performed on the raw inode simply pass @nop_mnt_idmap.
45 */
46 void generic_fillattr(struct mnt_idmap *idmap, u32 request_mask,
47 struct inode *inode, struct kstat *stat)
48 {
49 vfsuid_t vfsuid = i_uid_into_vfsuid(idmap, inode);
50 vfsgid_t vfsgid = i_gid_into_vfsgid(idmap, inode);
51
52 stat->dev = inode->i_sb->s_dev;
53 stat->ino = inode->i_ino;
54 stat->mode = inode->i_mode;
55 stat->nlink = inode->i_nlink;
56 stat->uid = vfsuid_into_kuid(vfsuid);
57 stat->gid = vfsgid_into_kgid(vfsgid);
58 stat->rdev = inode->i_rdev;
59 stat->size = i_size_read(inode);
60 stat->atime = inode_get_atime(inode);
61 stat->mtime = inode_get_mtime(inode);
62 stat->ctime = inode_get_ctime(inode);
63 stat->blksize = i_blocksize(inode);
64 stat->blocks = inode->i_blocks;
65
66 if ((request_mask & STATX_CHANGE_COOKIE) && IS_I_VERSION(inode)) {
67 stat->result_mask |= STATX_CHANGE_COOKIE;
68 stat->change_cookie = inode_query_iversion(inode);
69 }
70
71 }
72 EXPORT_SYMBOL(generic_fillattr);
73
74 /**
75 * generic_fill_statx_attr - Fill in the statx attributes from the inode flags
76 * @inode: Inode to use as the source
77 * @stat: Where to fill in the attribute flags
78 *
79 * Fill in the STATX_ATTR_* flags in the kstat structure for properties of the
80 * inode that are published on i_flags and enforced by the VFS.
81 */
82 void generic_fill_statx_attr(struct inode *inode, struct kstat *stat)
83 {
84 if (inode->i_flags & S_IMMUTABLE)
85 stat->attributes |= STATX_ATTR_IMMUTABLE;
86 if (inode->i_flags & S_APPEND)
87 stat->attributes |= STATX_ATTR_APPEND;
88 stat->attributes_mask |= KSTAT_ATTR_VFS_FLAGS;
89 }
90 EXPORT_SYMBOL(generic_fill_statx_attr);
91
92 /**
93 * generic_fill_statx_atomic_writes - Fill in atomic writes statx attributes
94 * @stat: Where to fill in the attribute flags
95 * @unit_min: Minimum supported atomic write length in bytes
96 * @unit_max: Maximum supported atomic write length in bytes
97 *
98 * Fill in the STATX{_ATTR}_WRITE_ATOMIC flags in the kstat structure from
99 * atomic write unit_min and unit_max values.
100 */
101 void generic_fill_statx_atomic_writes(struct kstat *stat,
102 unsigned int unit_min,
103 unsigned int unit_max)
104 {
105 /* Confirm that the request type is known */
106 stat->result_mask |= STATX_WRITE_ATOMIC;
107
108 /* Confirm that the file attribute type is known */
109 stat->attributes_mask |= STATX_ATTR_WRITE_ATOMIC;
110
111 if (unit_min) {
112 stat->atomic_write_unit_min = unit_min;
113 stat->atomic_write_unit_max = unit_max;
114 /* Initially only allow 1x segment */
115 stat->atomic_write_segments_max = 1;
116
117 /* Confirm atomic writes are actually supported */
118 stat->attributes |= STATX_ATTR_WRITE_ATOMIC;
119 }
120 }
121 EXPORT_SYMBOL_GPL(generic_fill_statx_atomic_writes);
122
123 /**
124 * vfs_getattr_nosec - getattr without security checks
125 * @path: file to get attributes from
126 * @stat: structure to return attributes in
127 * @request_mask: STATX_xxx flags indicating what the caller wants
128 * @query_flags: Query mode (AT_STATX_SYNC_TYPE)
129 *
130 * Get attributes without calling security_inode_getattr.
131 *
132 * Currently the only caller other than vfs_getattr is internal to the
133 * filehandle lookup code, which uses only the inode number and returns no
134 * attributes to any user. Any other code probably wants vfs_getattr.
135 */
136 int vfs_getattr_nosec(const struct path *path, struct kstat *stat,
137 u32 request_mask, unsigned int query_flags)
138 {
139 struct mnt_idmap *idmap;
140 struct inode *inode = d_backing_inode(path->dentry);
141
142 memset(stat, 0, sizeof(*stat));
143 stat->result_mask |= STATX_BASIC_STATS;
144 query_flags &= AT_STATX_SYNC_TYPE;
145
146 /* allow the fs to override these if it really wants to */
147 /* SB_NOATIME means filesystem supplies dummy atime value */
148 if (inode->i_sb->s_flags & SB_NOATIME)
149 stat->result_mask &= ~STATX_ATIME;
150
151 /*
152 * Note: If you add another clause to set an attribute flag, please
153 * update attributes_mask below.
154 */
155 if (IS_AUTOMOUNT(inode))
156 stat->attributes |= STATX_ATTR_AUTOMOUNT;
157
158 if (IS_DAX(inode))
159 stat->attributes |= STATX_ATTR_DAX;
160
161 stat->attributes_mask |= (STATX_ATTR_AUTOMOUNT |
162 STATX_ATTR_DAX);
163
164 idmap = mnt_idmap(path->mnt);
165 if (inode->i_op->getattr)
166 return inode->i_op->getattr(idmap, path, stat,
167 request_mask,
168 query_flags | AT_GETATTR_NOSEC);
169
170 generic_fillattr(idmap, request_mask, inode, stat);
171 return 0;
172 }
173 EXPORT_SYMBOL(vfs_getattr_nosec);
174
175 /*
176 * vfs_getattr - Get the enhanced basic attributes of a file
177 * @path: The file of interest
178 * @stat: Where to return the statistics
179 * @request_mask: STATX_xxx flags indicating what the caller wants
180 * @query_flags: Query mode (AT_STATX_SYNC_TYPE)
181 *
182 * Ask the filesystem for a file's attributes. The caller must indicate in
183 * request_mask and query_flags to indicate what they want.
184 *
185 * If the file is remote, the filesystem can be forced to update the attributes
186 * from the backing store by passing AT_STATX_FORCE_SYNC in query_flags or can
187 * suppress the update by passing AT_STATX_DONT_SYNC.
188 *
189 * Bits must have been set in request_mask to indicate which attributes the
190 * caller wants retrieving. Any such attribute not requested may be returned
191 * anyway, but the value may be approximate, and, if remote, may not have been
192 * synchronised with the server.
193 *
194 * 0 will be returned on success, and a -ve error code if unsuccessful.
195 */
196 int vfs_getattr(const struct path *path, struct kstat *stat,
197 u32 request_mask, unsigned int query_flags)
198 {
199 int retval;
200
201 if (WARN_ON_ONCE(query_flags & AT_GETATTR_NOSEC))
202 return -EPERM;
203
204 retval = security_inode_getattr(path);
205 if (retval)
206 return retval;
207 return vfs_getattr_nosec(path, stat, request_mask, query_flags);
208 }
209 EXPORT_SYMBOL(vfs_getattr);
210
211 /**
212 * vfs_fstat - Get the basic attributes by file descriptor
213 * @fd: The file descriptor referring to the file of interest
214 * @stat: The result structure to fill in.
215 *
216 * This function is a wrapper around vfs_getattr(). The main difference is
217 * that it uses a file descriptor to determine the file location.
218 *
219 * 0 will be returned on success, and a -ve error code if unsuccessful.
220 */
221 int vfs_fstat(int fd, struct kstat *stat)
222 {
223 struct fd f;
224 int error;
225
226 f = fdget_raw(fd);
227 if (!f.file)
228 return -EBADF;
229 error = vfs_getattr(&f.file->f_path, stat, STATX_BASIC_STATS, 0);
230 fdput(f);
231 return error;
232 }
233
234 int getname_statx_lookup_flags(int flags)
235 {
236 int lookup_flags = 0;
237
238 if (!(flags & AT_SYMLINK_NOFOLLOW))
239 lookup_flags |= LOOKUP_FOLLOW;
240 if (!(flags & AT_NO_AUTOMOUNT))
241 lookup_flags |= LOOKUP_AUTOMOUNT;
242 if (flags & AT_EMPTY_PATH)
243 lookup_flags |= LOOKUP_EMPTY;
244
245 return lookup_flags;
246 }
247
248 static int vfs_statx_path(struct path *path, int flags, struct kstat *stat,
249 u32 request_mask)
250 {
251 int error = vfs_getattr(path, stat, request_mask, flags);
252
253 if (request_mask & STATX_MNT_ID_UNIQUE) {
254 stat->mnt_id = real_mount(path->mnt)->mnt_id_unique;
255 stat->result_mask |= STATX_MNT_ID_UNIQUE;
256 } else {
257 stat->mnt_id = real_mount(path->mnt)->mnt_id;
258 stat->result_mask |= STATX_MNT_ID;
259 }
260
261 if (path_mounted(path))
262 stat->attributes |= STATX_ATTR_MOUNT_ROOT;
263 stat->attributes_mask |= STATX_ATTR_MOUNT_ROOT;
264
265 /*
266 * If this is a block device inode, override the filesystem
267 * attributes with the block device specific parameters that need to be
268 * obtained from the bdev backing inode.
269 */
270 if (S_ISBLK(stat->mode))
271 bdev_statx(path, stat, request_mask);
272
273 return error;
274 }
275
276 static int vfs_statx_fd(int fd, int flags, struct kstat *stat,
277 u32 request_mask)
278 {
279 CLASS(fd_raw, f)(fd);
280 if (!f.file)
281 return -EBADF;
282 return vfs_statx_path(&f.file->f_path, flags, stat, request_mask);
283 }
284
285 /**
286 * vfs_statx - Get basic and extra attributes by filename
287 * @dfd: A file descriptor representing the base dir for a relative filename
288 * @filename: The name of the file of interest
289 * @flags: Flags to control the query
290 * @stat: The result structure to fill in.
291 * @request_mask: STATX_xxx flags indicating what the caller wants
292 *
293 * This function is a wrapper around vfs_getattr(). The main difference is
294 * that it uses a filename and base directory to determine the file location.
295 * Additionally, the use of AT_SYMLINK_NOFOLLOW in flags will prevent a symlink
296 * at the given name from being referenced.
297 *
298 * 0 will be returned on success, and a -ve error code if unsuccessful.
299 */
300 static int vfs_statx(int dfd, struct filename *filename, int flags,
301 struct kstat *stat, u32 request_mask)
302 {
303 struct path path;
304 unsigned int lookup_flags = getname_statx_lookup_flags(flags);
305 int error;
306
307 if (flags & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT | AT_EMPTY_PATH |
308 AT_STATX_SYNC_TYPE))
309 return -EINVAL;
310
311 retry:
312 error = filename_lookup(dfd, filename, lookup_flags, &path, NULL);
313 if (error)
314 return error;
315 error = vfs_statx_path(&path, flags, stat, request_mask);
316 path_put(&path);
317 if (retry_estale(error, lookup_flags)) {
318 lookup_flags |= LOOKUP_REVAL;
319 goto retry;
320 }
321 return error;
322 }
323
324 int vfs_fstatat(int dfd, const char __user *filename,
325 struct kstat *stat, int flags)
326 {
327 int ret;
328 int statx_flags = flags | AT_NO_AUTOMOUNT;
329 struct filename *name;
330
331 /*
332 * Work around glibc turning fstat() into fstatat(AT_EMPTY_PATH)
333 *
334 * If AT_EMPTY_PATH is set, we expect the common case to be that
335 * empty path, and avoid doing all the extra pathname work.
336 */
337 if (flags == AT_EMPTY_PATH && vfs_empty_path(dfd, filename))
338 return vfs_fstat(dfd, stat);
339
340 name = getname_flags(filename, getname_statx_lookup_flags(statx_flags));
341 ret = vfs_statx(dfd, name, statx_flags, stat, STATX_BASIC_STATS);
342 putname(name);
343
344 return ret;
345 }
346
347 #ifdef __ARCH_WANT_OLD_STAT
348
349 /*
350 * For backward compatibility? Maybe this should be moved
351 * into arch/i386 instead?
352 */
353 static int cp_old_stat(struct kstat *stat, struct __old_kernel_stat __user * statbuf)
354 {
355 static int warncount = 5;
356 struct __old_kernel_stat tmp;
357
358 if (warncount > 0) {
359 warncount--;
360 printk(KERN_WARNING "VFS: Warning: %s using old stat() call. Recompile your binary.\n",
361 current->comm);
362 } else if (warncount < 0) {
363 /* it's laughable, but... */
364 warncount = 0;
365 }
366
367 memset(&tmp, 0, sizeof(struct __old_kernel_stat));
368 tmp.st_dev = old_encode_dev(stat->dev);
369 tmp.st_ino = stat->ino;
370 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
371 return -EOVERFLOW;
372 tmp.st_mode = stat->mode;
373 tmp.st_nlink = stat->nlink;
374 if (tmp.st_nlink != stat->nlink)
375 return -EOVERFLOW;
376 SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
377 SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
378 tmp.st_rdev = old_encode_dev(stat->rdev);
379 #if BITS_PER_LONG == 32
380 if (stat->size > MAX_NON_LFS)
381 return -EOVERFLOW;
382 #endif
383 tmp.st_size = stat->size;
384 tmp.st_atime = stat->atime.tv_sec;
385 tmp.st_mtime = stat->mtime.tv_sec;
386 tmp.st_ctime = stat->ctime.tv_sec;
387 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
388 }
389
390 SYSCALL_DEFINE2(stat, const char __user *, filename,
391 struct __old_kernel_stat __user *, statbuf)
392 {
393 struct kstat stat;
394 int error;
395
396 error = vfs_stat(filename, &stat);
397 if (error)
398 return error;
399
400 return cp_old_stat(&stat, statbuf);
401 }
402
403 SYSCALL_DEFINE2(lstat, const char __user *, filename,
404 struct __old_kernel_stat __user *, statbuf)
405 {
406 struct kstat stat;
407 int error;
408
409 error = vfs_lstat(filename, &stat);
410 if (error)
411 return error;
412
413 return cp_old_stat(&stat, statbuf);
414 }
415
416 SYSCALL_DEFINE2(fstat, unsigned int, fd, struct __old_kernel_stat __user *, statbuf)
417 {
418 struct kstat stat;
419 int error = vfs_fstat(fd, &stat);
420
421 if (!error)
422 error = cp_old_stat(&stat, statbuf);
423
424 return error;
425 }
426
427 #endif /* __ARCH_WANT_OLD_STAT */
428
429 #ifdef __ARCH_WANT_NEW_STAT
430
431 #ifndef INIT_STRUCT_STAT_PADDING
432 # define INIT_STRUCT_STAT_PADDING(st) memset(&st, 0, sizeof(st))
433 #endif
434
435 static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf)
436 {
437 struct stat tmp;
438
439 if (sizeof(tmp.st_dev) < 4 && !old_valid_dev(stat->dev))
440 return -EOVERFLOW;
441 if (sizeof(tmp.st_rdev) < 4 && !old_valid_dev(stat->rdev))
442 return -EOVERFLOW;
443 #if BITS_PER_LONG == 32
444 if (stat->size > MAX_NON_LFS)
445 return -EOVERFLOW;
446 #endif
447
448 INIT_STRUCT_STAT_PADDING(tmp);
449 tmp.st_dev = new_encode_dev(stat->dev);
450 tmp.st_ino = stat->ino;
451 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
452 return -EOVERFLOW;
453 tmp.st_mode = stat->mode;
454 tmp.st_nlink = stat->nlink;
455 if (tmp.st_nlink != stat->nlink)
456 return -EOVERFLOW;
457 SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
458 SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
459 tmp.st_rdev = new_encode_dev(stat->rdev);
460 tmp.st_size = stat->size;
461 tmp.st_atime = stat->atime.tv_sec;
462 tmp.st_mtime = stat->mtime.tv_sec;
463 tmp.st_ctime = stat->ctime.tv_sec;
464 #ifdef STAT_HAVE_NSEC
465 tmp.st_atime_nsec = stat->atime.tv_nsec;
466 tmp.st_mtime_nsec = stat->mtime.tv_nsec;
467 tmp.st_ctime_nsec = stat->ctime.tv_nsec;
468 #endif
469 tmp.st_blocks = stat->blocks;
470 tmp.st_blksize = stat->blksize;
471 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
472 }
473
474 SYSCALL_DEFINE2(newstat, const char __user *, filename,
475 struct stat __user *, statbuf)
476 {
477 struct kstat stat;
478 int error = vfs_stat(filename, &stat);
479
480 if (error)
481 return error;
482 return cp_new_stat(&stat, statbuf);
483 }
484
485 SYSCALL_DEFINE2(newlstat, const char __user *, filename,
486 struct stat __user *, statbuf)
487 {
488 struct kstat stat;
489 int error;
490
491 error = vfs_lstat(filename, &stat);
492 if (error)
493 return error;
494
495 return cp_new_stat(&stat, statbuf);
496 }
497
498 #if !defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_SYS_NEWFSTATAT)
499 SYSCALL_DEFINE4(newfstatat, int, dfd, const char __user *, filename,
500 struct stat __user *, statbuf, int, flag)
501 {
502 struct kstat stat;
503 int error;
504
505 error = vfs_fstatat(dfd, filename, &stat, flag);
506 if (error)
507 return error;
508 return cp_new_stat(&stat, statbuf);
509 }
510 #endif
511
512 SYSCALL_DEFINE2(newfstat, unsigned int, fd, struct stat __user *, statbuf)
513 {
514 struct kstat stat;
515 int error = vfs_fstat(fd, &stat);
516
517 if (!error)
518 error = cp_new_stat(&stat, statbuf);
519
520 return error;
521 }
522 #endif
523
524 static int do_readlinkat(int dfd, const char __user *pathname,
525 char __user *buf, int bufsiz)
526 {
527 struct path path;
528 struct filename *name;
529 int error;
530 unsigned int lookup_flags = LOOKUP_EMPTY;
531
532 if (bufsiz <= 0)
533 return -EINVAL;
534
535 retry:
536 name = getname_flags(pathname, lookup_flags);
537 error = filename_lookup(dfd, name, lookup_flags, &path, NULL);
538 if (unlikely(error)) {
539 putname(name);
540 return error;
541 }
542
543 /*
544 * AFS mountpoints allow readlink(2) but are not symlinks
545 */
546 if (d_is_symlink(path.dentry) ||
547 d_backing_inode(path.dentry)->i_op->readlink) {
548 error = security_inode_readlink(path.dentry);
549 if (!error) {
550 touch_atime(&path);
551 error = vfs_readlink(path.dentry, buf, bufsiz);
552 }
553 } else {
554 error = (name->name[0] == '\0') ? -ENOENT : -EINVAL;
555 }
556 path_put(&path);
557 putname(name);
558 if (retry_estale(error, lookup_flags)) {
559 lookup_flags |= LOOKUP_REVAL;
560 goto retry;
561 }
562 return error;
563 }
564
565 SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname,
566 char __user *, buf, int, bufsiz)
567 {
568 return do_readlinkat(dfd, pathname, buf, bufsiz);
569 }
570
571 SYSCALL_DEFINE3(readlink, const char __user *, path, char __user *, buf,
572 int, bufsiz)
573 {
574 return do_readlinkat(AT_FDCWD, path, buf, bufsiz);
575 }
576
577
578 /* ---------- LFS-64 ----------- */
579 #if defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_COMPAT_STAT64)
580
581 #ifndef INIT_STRUCT_STAT64_PADDING
582 # define INIT_STRUCT_STAT64_PADDING(st) memset(&st, 0, sizeof(st))
583 #endif
584
585 static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf)
586 {
587 struct stat64 tmp;
588
589 INIT_STRUCT_STAT64_PADDING(tmp);
590 #ifdef CONFIG_MIPS
591 /* mips has weird padding, so we don't get 64 bits there */
592 tmp.st_dev = new_encode_dev(stat->dev);
593 tmp.st_rdev = new_encode_dev(stat->rdev);
594 #else
595 tmp.st_dev = huge_encode_dev(stat->dev);
596 tmp.st_rdev = huge_encode_dev(stat->rdev);
597 #endif
598 tmp.st_ino = stat->ino;
599 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
600 return -EOVERFLOW;
601 #ifdef STAT64_HAS_BROKEN_ST_INO
602 tmp.__st_ino = stat->ino;
603 #endif
604 tmp.st_mode = stat->mode;
605 tmp.st_nlink = stat->nlink;
606 tmp.st_uid = from_kuid_munged(current_user_ns(), stat->uid);
607 tmp.st_gid = from_kgid_munged(current_user_ns(), stat->gid);
608 tmp.st_atime = stat->atime.tv_sec;
609 tmp.st_atime_nsec = stat->atime.tv_nsec;
610 tmp.st_mtime = stat->mtime.tv_sec;
611 tmp.st_mtime_nsec = stat->mtime.tv_nsec;
612 tmp.st_ctime = stat->ctime.tv_sec;
613 tmp.st_ctime_nsec = stat->ctime.tv_nsec;
614 tmp.st_size = stat->size;
615 tmp.st_blocks = stat->blocks;
616 tmp.st_blksize = stat->blksize;
617 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
618 }
619
620 SYSCALL_DEFINE2(stat64, const char __user *, filename,
621 struct stat64 __user *, statbuf)
622 {
623 struct kstat stat;
624 int error = vfs_stat(filename, &stat);
625
626 if (!error)
627 error = cp_new_stat64(&stat, statbuf);
628
629 return error;
630 }
631
632 SYSCALL_DEFINE2(lstat64, const char __user *, filename,
633 struct stat64 __user *, statbuf)
634 {
635 struct kstat stat;
636 int error = vfs_lstat(filename, &stat);
637
638 if (!error)
639 error = cp_new_stat64(&stat, statbuf);
640
641 return error;
642 }
643
644 SYSCALL_DEFINE2(fstat64, unsigned long, fd, struct stat64 __user *, statbuf)
645 {
646 struct kstat stat;
647 int error = vfs_fstat(fd, &stat);
648
649 if (!error)
650 error = cp_new_stat64(&stat, statbuf);
651
652 return error;
653 }
654
655 SYSCALL_DEFINE4(fstatat64, int, dfd, const char __user *, filename,
656 struct stat64 __user *, statbuf, int, flag)
657 {
658 struct kstat stat;
659 int error;
660
661 error = vfs_fstatat(dfd, filename, &stat, flag);
662 if (error)
663 return error;
664 return cp_new_stat64(&stat, statbuf);
665 }
666 #endif /* __ARCH_WANT_STAT64 || __ARCH_WANT_COMPAT_STAT64 */
667
668 static noinline_for_stack int
669 cp_statx(const struct kstat *stat, struct statx __user *buffer)
670 {
671 struct statx tmp;
672
673 memset(&tmp, 0, sizeof(tmp));
674
675 /* STATX_CHANGE_COOKIE is kernel-only for now */
676 tmp.stx_mask = stat->result_mask & ~STATX_CHANGE_COOKIE;
677 tmp.stx_blksize = stat->blksize;
678 /* STATX_ATTR_CHANGE_MONOTONIC is kernel-only for now */
679 tmp.stx_attributes = stat->attributes & ~STATX_ATTR_CHANGE_MONOTONIC;
680 tmp.stx_nlink = stat->nlink;
681 tmp.stx_uid = from_kuid_munged(current_user_ns(), stat->uid);
682 tmp.stx_gid = from_kgid_munged(current_user_ns(), stat->gid);
683 tmp.stx_mode = stat->mode;
684 tmp.stx_ino = stat->ino;
685 tmp.stx_size = stat->size;
686 tmp.stx_blocks = stat->blocks;
687 tmp.stx_attributes_mask = stat->attributes_mask;
688 tmp.stx_atime.tv_sec = stat->atime.tv_sec;
689 tmp.stx_atime.tv_nsec = stat->atime.tv_nsec;
690 tmp.stx_btime.tv_sec = stat->btime.tv_sec;
691 tmp.stx_btime.tv_nsec = stat->btime.tv_nsec;
692 tmp.stx_ctime.tv_sec = stat->ctime.tv_sec;
693 tmp.stx_ctime.tv_nsec = stat->ctime.tv_nsec;
694 tmp.stx_mtime.tv_sec = stat->mtime.tv_sec;
695 tmp.stx_mtime.tv_nsec = stat->mtime.tv_nsec;
696 tmp.stx_rdev_major = MAJOR(stat->rdev);
697 tmp.stx_rdev_minor = MINOR(stat->rdev);
698 tmp.stx_dev_major = MAJOR(stat->dev);
699 tmp.stx_dev_minor = MINOR(stat->dev);
700 tmp.stx_mnt_id = stat->mnt_id;
701 tmp.stx_dio_mem_align = stat->dio_mem_align;
702 tmp.stx_dio_offset_align = stat->dio_offset_align;
703 tmp.stx_subvol = stat->subvol;
704 tmp.stx_atomic_write_unit_min = stat->atomic_write_unit_min;
705 tmp.stx_atomic_write_unit_max = stat->atomic_write_unit_max;
706 tmp.stx_atomic_write_segments_max = stat->atomic_write_segments_max;
707
708 return copy_to_user(buffer, &tmp, sizeof(tmp)) ? -EFAULT : 0;
709 }
710
711 int do_statx(int dfd, struct filename *filename, unsigned int flags,
712 unsigned int mask, struct statx __user *buffer)
713 {
714 struct kstat stat;
715 int error;
716
717 if (mask & STATX__RESERVED)
718 return -EINVAL;
719 if ((flags & AT_STATX_SYNC_TYPE) == AT_STATX_SYNC_TYPE)
720 return -EINVAL;
721
722 /*
723 * STATX_CHANGE_COOKIE is kernel-only for now. Ignore requests
724 * from userland.
725 */
726 mask &= ~STATX_CHANGE_COOKIE;
727
728 error = vfs_statx(dfd, filename, flags, &stat, mask);
729 if (error)
730 return error;
731
732 return cp_statx(&stat, buffer);
733 }
734
735 int do_statx_fd(int fd, unsigned int flags, unsigned int mask,
736 struct statx __user *buffer)
737 {
738 struct kstat stat;
739 int error;
740
741 if (mask & STATX__RESERVED)
742 return -EINVAL;
743 if ((flags & AT_STATX_SYNC_TYPE) == AT_STATX_SYNC_TYPE)
744 return -EINVAL;
745
746 /*
747 * STATX_CHANGE_COOKIE is kernel-only for now. Ignore requests
748 * from userland.
749 */
750 mask &= ~STATX_CHANGE_COOKIE;
751
752 error = vfs_statx_fd(fd, flags, &stat, mask);
753 if (error)
754 return error;
755
756 return cp_statx(&stat, buffer);
757 }
758
759 /**
760 * sys_statx - System call to get enhanced stats
761 * @dfd: Base directory to pathwalk from *or* fd to stat.
762 * @filename: File to stat or either NULL or "" with AT_EMPTY_PATH
763 * @flags: AT_* flags to control pathwalk.
764 * @mask: Parts of statx struct actually required.
765 * @buffer: Result buffer.
766 *
767 * Note that fstat() can be emulated by setting dfd to the fd of interest,
768 * supplying "" (or preferably NULL) as the filename and setting AT_EMPTY_PATH
769 * in the flags.
770 */
771 SYSCALL_DEFINE5(statx,
772 int, dfd, const char __user *, filename, unsigned, flags,
773 unsigned int, mask,
774 struct statx __user *, buffer)
775 {
776 int ret;
777 unsigned lflags;
778 struct filename *name;
779
780 /*
781 * Short-circuit handling of NULL and "" paths.
782 *
783 * For a NULL path we require and accept only the AT_EMPTY_PATH flag
784 * (possibly |'d with AT_STATX flags).
785 *
786 * However, glibc on 32-bit architectures implements fstatat as statx
787 * with the "" pathname and AT_NO_AUTOMOUNT | AT_EMPTY_PATH flags.
788 * Supporting this results in the uglification below.
789 */
790 lflags = flags & ~(AT_NO_AUTOMOUNT | AT_STATX_SYNC_TYPE);
791 if (lflags == AT_EMPTY_PATH && vfs_empty_path(dfd, filename))
792 return do_statx_fd(dfd, flags & ~AT_NO_AUTOMOUNT, mask, buffer);
793
794 name = getname_flags(filename, getname_statx_lookup_flags(flags));
795 ret = do_statx(dfd, name, flags, mask, buffer);
796 putname(name);
797
798 return ret;
799 }
800
801 #if defined(CONFIG_COMPAT) && defined(__ARCH_WANT_COMPAT_STAT)
802 static int cp_compat_stat(struct kstat *stat, struct compat_stat __user *ubuf)
803 {
804 struct compat_stat tmp;
805
806 if (sizeof(tmp.st_dev) < 4 && !old_valid_dev(stat->dev))
807 return -EOVERFLOW;
808 if (sizeof(tmp.st_rdev) < 4 && !old_valid_dev(stat->rdev))
809 return -EOVERFLOW;
810
811 memset(&tmp, 0, sizeof(tmp));
812 tmp.st_dev = new_encode_dev(stat->dev);
813 tmp.st_ino = stat->ino;
814 if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
815 return -EOVERFLOW;
816 tmp.st_mode = stat->mode;
817 tmp.st_nlink = stat->nlink;
818 if (tmp.st_nlink != stat->nlink)
819 return -EOVERFLOW;
820 SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
821 SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
822 tmp.st_rdev = new_encode_dev(stat->rdev);
823 if ((u64) stat->size > MAX_NON_LFS)
824 return -EOVERFLOW;
825 tmp.st_size = stat->size;
826 tmp.st_atime = stat->atime.tv_sec;
827 tmp.st_atime_nsec = stat->atime.tv_nsec;
828 tmp.st_mtime = stat->mtime.tv_sec;
829 tmp.st_mtime_nsec = stat->mtime.tv_nsec;
830 tmp.st_ctime = stat->ctime.tv_sec;
831 tmp.st_ctime_nsec = stat->ctime.tv_nsec;
832 tmp.st_blocks = stat->blocks;
833 tmp.st_blksize = stat->blksize;
834 return copy_to_user(ubuf, &tmp, sizeof(tmp)) ? -EFAULT : 0;
835 }
836
837 COMPAT_SYSCALL_DEFINE2(newstat, const char __user *, filename,
838 struct compat_stat __user *, statbuf)
839 {
840 struct kstat stat;
841 int error;
842
843 error = vfs_stat(filename, &stat);
844 if (error)
845 return error;
846 return cp_compat_stat(&stat, statbuf);
847 }
848
849 COMPAT_SYSCALL_DEFINE2(newlstat, const char __user *, filename,
850 struct compat_stat __user *, statbuf)
851 {
852 struct kstat stat;
853 int error;
854
855 error = vfs_lstat(filename, &stat);
856 if (error)
857 return error;
858 return cp_compat_stat(&stat, statbuf);
859 }
860
861 #ifndef __ARCH_WANT_STAT64
862 COMPAT_SYSCALL_DEFINE4(newfstatat, unsigned int, dfd,
863 const char __user *, filename,
864 struct compat_stat __user *, statbuf, int, flag)
865 {
866 struct kstat stat;
867 int error;
868
869 error = vfs_fstatat(dfd, filename, &stat, flag);
870 if (error)
871 return error;
872 return cp_compat_stat(&stat, statbuf);
873 }
874 #endif
875
876 COMPAT_SYSCALL_DEFINE2(newfstat, unsigned int, fd,
877 struct compat_stat __user *, statbuf)
878 {
879 struct kstat stat;
880 int error = vfs_fstat(fd, &stat);
881
882 if (!error)
883 error = cp_compat_stat(&stat, statbuf);
884 return error;
885 }
886 #endif
887
888 /* Caller is here responsible for sufficient locking (ie. inode->i_lock) */
889 void __inode_add_bytes(struct inode *inode, loff_t bytes)
890 {
891 inode->i_blocks += bytes >> 9;
892 bytes &= 511;
893 inode->i_bytes += bytes;
894 if (inode->i_bytes >= 512) {
895 inode->i_blocks++;
896 inode->i_bytes -= 512;
897 }
898 }
899 EXPORT_SYMBOL(__inode_add_bytes);
900
901 void inode_add_bytes(struct inode *inode, loff_t bytes)
902 {
903 spin_lock(&inode->i_lock);
904 __inode_add_bytes(inode, bytes);
905 spin_unlock(&inode->i_lock);
906 }
907
908 EXPORT_SYMBOL(inode_add_bytes);
909
910 void __inode_sub_bytes(struct inode *inode, loff_t bytes)
911 {
912 inode->i_blocks -= bytes >> 9;
913 bytes &= 511;
914 if (inode->i_bytes < bytes) {
915 inode->i_blocks--;
916 inode->i_bytes += 512;
917 }
918 inode->i_bytes -= bytes;
919 }
920
921 EXPORT_SYMBOL(__inode_sub_bytes);
922
923 void inode_sub_bytes(struct inode *inode, loff_t bytes)
924 {
925 spin_lock(&inode->i_lock);
926 __inode_sub_bytes(inode, bytes);
927 spin_unlock(&inode->i_lock);
928 }
929
930 EXPORT_SYMBOL(inode_sub_bytes);
931
932 loff_t inode_get_bytes(struct inode *inode)
933 {
934 loff_t ret;
935
936 spin_lock(&inode->i_lock);
937 ret = __inode_get_bytes(inode);
938 spin_unlock(&inode->i_lock);
939 return ret;
940 }
941
942 EXPORT_SYMBOL(inode_get_bytes);
943
944 void inode_set_bytes(struct inode *inode, loff_t bytes)
945 {
946 /* Caller is here responsible for sufficient locking
947 * (ie. inode->i_lock) */
948 inode->i_blocks = bytes >> 9;
949 inode->i_bytes = bytes & 511;
950 }
951
952 EXPORT_SYMBOL(inode_set_bytes);
953
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