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