]>
git.ipfire.org Git - thirdparty/linux.git/blob - fs/stat.c
4 * Copyright (C) 1991, 1992 Linus Torvalds
7 #include <linux/export.h>
9 #include <linux/errno.h>
10 #include <linux/file.h>
11 #include <linux/highuid.h>
13 #include <linux/namei.h>
14 #include <linux/security.h>
15 #include <linux/cred.h>
16 #include <linux/syscalls.h>
17 #include <linux/pagemap.h>
19 #include <linux/uaccess.h>
20 #include <asm/unistd.h>
23 * generic_fillattr - Fill in the basic attributes from the inode struct
24 * @inode: Inode to use as the source
25 * @stat: Where to fill in the attributes
27 * Fill in the basic attributes in the kstat structure from data that's to be
28 * found on the VFS inode structure. This is the default if no getattr inode
29 * operation is supplied.
31 void generic_fillattr(struct inode
*inode
, struct kstat
*stat
)
33 stat
->dev
= inode
->i_sb
->s_dev
;
34 stat
->ino
= inode
->i_ino
;
35 stat
->mode
= inode
->i_mode
;
36 stat
->nlink
= inode
->i_nlink
;
37 stat
->uid
= inode
->i_uid
;
38 stat
->gid
= inode
->i_gid
;
39 stat
->rdev
= inode
->i_rdev
;
40 stat
->size
= i_size_read(inode
);
41 stat
->atime
= inode
->i_atime
;
42 stat
->mtime
= inode
->i_mtime
;
43 stat
->ctime
= inode
->i_ctime
;
44 stat
->blksize
= i_blocksize(inode
);
45 stat
->blocks
= inode
->i_blocks
;
47 if (IS_NOATIME(inode
))
48 stat
->result_mask
&= ~STATX_ATIME
;
49 if (IS_AUTOMOUNT(inode
))
50 stat
->attributes
|= STATX_ATTR_AUTOMOUNT
;
52 EXPORT_SYMBOL(generic_fillattr
);
55 * vfs_getattr_nosec - getattr without security checks
56 * @path: file to get attributes from
57 * @stat: structure to return attributes in
58 * @request_mask: STATX_xxx flags indicating what the caller wants
59 * @query_flags: Query mode (KSTAT_QUERY_FLAGS)
61 * Get attributes without calling security_inode_getattr.
63 * Currently the only caller other than vfs_getattr is internal to the
64 * filehandle lookup code, which uses only the inode number and returns no
65 * attributes to any user. Any other code probably wants vfs_getattr.
67 int vfs_getattr_nosec(const struct path
*path
, struct kstat
*stat
,
68 u32 request_mask
, unsigned int query_flags
)
70 struct inode
*inode
= d_backing_inode(path
->dentry
);
72 memset(stat
, 0, sizeof(*stat
));
73 stat
->result_mask
|= STATX_BASIC_STATS
;
74 request_mask
&= STATX_ALL
;
75 query_flags
&= KSTAT_QUERY_FLAGS
;
76 if (inode
->i_op
->getattr
)
77 return inode
->i_op
->getattr(path
, stat
, request_mask
,
80 generic_fillattr(inode
, stat
);
83 EXPORT_SYMBOL(vfs_getattr_nosec
);
86 * vfs_getattr - Get the enhanced basic attributes of a file
87 * @path: The file of interest
88 * @stat: Where to return the statistics
89 * @request_mask: STATX_xxx flags indicating what the caller wants
90 * @query_flags: Query mode (KSTAT_QUERY_FLAGS)
92 * Ask the filesystem for a file's attributes. The caller must indicate in
93 * request_mask and query_flags to indicate what they want.
95 * If the file is remote, the filesystem can be forced to update the attributes
96 * from the backing store by passing AT_STATX_FORCE_SYNC in query_flags or can
97 * suppress the update by passing AT_STATX_DONT_SYNC.
99 * Bits must have been set in request_mask to indicate which attributes the
100 * caller wants retrieving. Any such attribute not requested may be returned
101 * anyway, but the value may be approximate, and, if remote, may not have been
102 * synchronised with the server.
104 * 0 will be returned on success, and a -ve error code if unsuccessful.
106 int vfs_getattr(const struct path
*path
, struct kstat
*stat
,
107 u32 request_mask
, unsigned int query_flags
)
111 retval
= security_inode_getattr(path
);
114 return vfs_getattr_nosec(path
, stat
, request_mask
, query_flags
);
116 EXPORT_SYMBOL(vfs_getattr
);
119 * vfs_statx_fd - Get the enhanced basic attributes by file descriptor
120 * @fd: The file descriptor referring to the file of interest
121 * @stat: The result structure to fill in.
122 * @request_mask: STATX_xxx flags indicating what the caller wants
123 * @query_flags: Query mode (KSTAT_QUERY_FLAGS)
125 * This function is a wrapper around vfs_getattr(). The main difference is
126 * that it uses a file descriptor to determine the file location.
128 * 0 will be returned on success, and a -ve error code if unsuccessful.
130 int vfs_statx_fd(unsigned int fd
, struct kstat
*stat
,
131 u32 request_mask
, unsigned int query_flags
)
136 if (query_flags
& ~KSTAT_QUERY_FLAGS
)
141 error
= vfs_getattr(&f
.file
->f_path
, stat
,
142 request_mask
, query_flags
);
147 EXPORT_SYMBOL(vfs_statx_fd
);
150 * vfs_statx - Get basic and extra attributes by filename
151 * @dfd: A file descriptor representing the base dir for a relative filename
152 * @filename: The name of the file of interest
153 * @flags: Flags to control the query
154 * @stat: The result structure to fill in.
155 * @request_mask: STATX_xxx flags indicating what the caller wants
157 * This function is a wrapper around vfs_getattr(). The main difference is
158 * that it uses a filename and base directory to determine the file location.
159 * Additionally, the use of AT_SYMLINK_NOFOLLOW in flags will prevent a symlink
160 * at the given name from being referenced.
162 * 0 will be returned on success, and a -ve error code if unsuccessful.
164 int vfs_statx(int dfd
, const char __user
*filename
, int flags
,
165 struct kstat
*stat
, u32 request_mask
)
169 unsigned int lookup_flags
= LOOKUP_FOLLOW
| LOOKUP_AUTOMOUNT
;
171 if ((flags
& ~(AT_SYMLINK_NOFOLLOW
| AT_NO_AUTOMOUNT
|
172 AT_EMPTY_PATH
| KSTAT_QUERY_FLAGS
)) != 0)
175 if (flags
& AT_SYMLINK_NOFOLLOW
)
176 lookup_flags
&= ~LOOKUP_FOLLOW
;
177 if (flags
& AT_NO_AUTOMOUNT
)
178 lookup_flags
&= ~LOOKUP_AUTOMOUNT
;
179 if (flags
& AT_EMPTY_PATH
)
180 lookup_flags
|= LOOKUP_EMPTY
;
183 error
= user_path_at(dfd
, filename
, lookup_flags
, &path
);
187 error
= vfs_getattr(&path
, stat
, request_mask
, flags
);
189 if (retry_estale(error
, lookup_flags
)) {
190 lookup_flags
|= LOOKUP_REVAL
;
196 EXPORT_SYMBOL(vfs_statx
);
199 #ifdef __ARCH_WANT_OLD_STAT
202 * For backward compatibility? Maybe this should be moved
203 * into arch/i386 instead?
205 static int cp_old_stat(struct kstat
*stat
, struct __old_kernel_stat __user
* statbuf
)
207 static int warncount
= 5;
208 struct __old_kernel_stat tmp
;
212 printk(KERN_WARNING
"VFS: Warning: %s using old stat() call. Recompile your binary.\n",
214 } else if (warncount
< 0) {
215 /* it's laughable, but... */
219 memset(&tmp
, 0, sizeof(struct __old_kernel_stat
));
220 tmp
.st_dev
= old_encode_dev(stat
->dev
);
221 tmp
.st_ino
= stat
->ino
;
222 if (sizeof(tmp
.st_ino
) < sizeof(stat
->ino
) && tmp
.st_ino
!= stat
->ino
)
224 tmp
.st_mode
= stat
->mode
;
225 tmp
.st_nlink
= stat
->nlink
;
226 if (tmp
.st_nlink
!= stat
->nlink
)
228 SET_UID(tmp
.st_uid
, from_kuid_munged(current_user_ns(), stat
->uid
));
229 SET_GID(tmp
.st_gid
, from_kgid_munged(current_user_ns(), stat
->gid
));
230 tmp
.st_rdev
= old_encode_dev(stat
->rdev
);
231 #if BITS_PER_LONG == 32
232 if (stat
->size
> MAX_NON_LFS
)
235 tmp
.st_size
= stat
->size
;
236 tmp
.st_atime
= stat
->atime
.tv_sec
;
237 tmp
.st_mtime
= stat
->mtime
.tv_sec
;
238 tmp
.st_ctime
= stat
->ctime
.tv_sec
;
239 return copy_to_user(statbuf
,&tmp
,sizeof(tmp
)) ? -EFAULT
: 0;
242 SYSCALL_DEFINE2(stat
, const char __user
*, filename
,
243 struct __old_kernel_stat __user
*, statbuf
)
248 error
= vfs_stat(filename
, &stat
);
252 return cp_old_stat(&stat
, statbuf
);
255 SYSCALL_DEFINE2(lstat
, const char __user
*, filename
,
256 struct __old_kernel_stat __user
*, statbuf
)
261 error
= vfs_lstat(filename
, &stat
);
265 return cp_old_stat(&stat
, statbuf
);
268 SYSCALL_DEFINE2(fstat
, unsigned int, fd
, struct __old_kernel_stat __user
*, statbuf
)
271 int error
= vfs_fstat(fd
, &stat
);
274 error
= cp_old_stat(&stat
, statbuf
);
279 #endif /* __ARCH_WANT_OLD_STAT */
281 #if BITS_PER_LONG == 32
282 # define choose_32_64(a,b) a
284 # define choose_32_64(a,b) b
287 #define valid_dev(x) choose_32_64(old_valid_dev(x),true)
288 #define encode_dev(x) choose_32_64(old_encode_dev,new_encode_dev)(x)
290 #ifndef INIT_STRUCT_STAT_PADDING
291 # define INIT_STRUCT_STAT_PADDING(st) memset(&st, 0, sizeof(st))
294 static int cp_new_stat(struct kstat
*stat
, struct stat __user
*statbuf
)
298 if (!valid_dev(stat
->dev
) || !valid_dev(stat
->rdev
))
300 #if BITS_PER_LONG == 32
301 if (stat
->size
> MAX_NON_LFS
)
305 INIT_STRUCT_STAT_PADDING(tmp
);
306 tmp
.st_dev
= encode_dev(stat
->dev
);
307 tmp
.st_ino
= stat
->ino
;
308 if (sizeof(tmp
.st_ino
) < sizeof(stat
->ino
) && tmp
.st_ino
!= stat
->ino
)
310 tmp
.st_mode
= stat
->mode
;
311 tmp
.st_nlink
= stat
->nlink
;
312 if (tmp
.st_nlink
!= stat
->nlink
)
314 SET_UID(tmp
.st_uid
, from_kuid_munged(current_user_ns(), stat
->uid
));
315 SET_GID(tmp
.st_gid
, from_kgid_munged(current_user_ns(), stat
->gid
));
316 tmp
.st_rdev
= encode_dev(stat
->rdev
);
317 tmp
.st_size
= stat
->size
;
318 tmp
.st_atime
= stat
->atime
.tv_sec
;
319 tmp
.st_mtime
= stat
->mtime
.tv_sec
;
320 tmp
.st_ctime
= stat
->ctime
.tv_sec
;
321 #ifdef STAT_HAVE_NSEC
322 tmp
.st_atime_nsec
= stat
->atime
.tv_nsec
;
323 tmp
.st_mtime_nsec
= stat
->mtime
.tv_nsec
;
324 tmp
.st_ctime_nsec
= stat
->ctime
.tv_nsec
;
326 tmp
.st_blocks
= stat
->blocks
;
327 tmp
.st_blksize
= stat
->blksize
;
328 return copy_to_user(statbuf
,&tmp
,sizeof(tmp
)) ? -EFAULT
: 0;
331 SYSCALL_DEFINE2(newstat
, const char __user
*, filename
,
332 struct stat __user
*, statbuf
)
335 int error
= vfs_stat(filename
, &stat
);
339 return cp_new_stat(&stat
, statbuf
);
342 SYSCALL_DEFINE2(newlstat
, const char __user
*, filename
,
343 struct stat __user
*, statbuf
)
348 error
= vfs_lstat(filename
, &stat
);
352 return cp_new_stat(&stat
, statbuf
);
355 #if !defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_SYS_NEWFSTATAT)
356 SYSCALL_DEFINE4(newfstatat
, int, dfd
, const char __user
*, filename
,
357 struct stat __user
*, statbuf
, int, flag
)
362 error
= vfs_fstatat(dfd
, filename
, &stat
, flag
);
365 return cp_new_stat(&stat
, statbuf
);
369 SYSCALL_DEFINE2(newfstat
, unsigned int, fd
, struct stat __user
*, statbuf
)
372 int error
= vfs_fstat(fd
, &stat
);
375 error
= cp_new_stat(&stat
, statbuf
);
380 SYSCALL_DEFINE4(readlinkat
, int, dfd
, const char __user
*, pathname
,
381 char __user
*, buf
, int, bufsiz
)
386 unsigned int lookup_flags
= LOOKUP_EMPTY
;
392 error
= user_path_at_empty(dfd
, pathname
, lookup_flags
, &path
, &empty
);
394 struct inode
*inode
= d_backing_inode(path
.dentry
);
396 error
= empty
? -ENOENT
: -EINVAL
;
398 * AFS mountpoints allow readlink(2) but are not symlinks
400 if (d_is_symlink(path
.dentry
) || inode
->i_op
->readlink
) {
401 error
= security_inode_readlink(path
.dentry
);
404 error
= vfs_readlink(path
.dentry
, buf
, bufsiz
);
408 if (retry_estale(error
, lookup_flags
)) {
409 lookup_flags
|= LOOKUP_REVAL
;
416 SYSCALL_DEFINE3(readlink
, const char __user
*, path
, char __user
*, buf
,
419 return sys_readlinkat(AT_FDCWD
, path
, buf
, bufsiz
);
423 /* ---------- LFS-64 ----------- */
424 #if defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_COMPAT_STAT64)
426 #ifndef INIT_STRUCT_STAT64_PADDING
427 # define INIT_STRUCT_STAT64_PADDING(st) memset(&st, 0, sizeof(st))
430 static long cp_new_stat64(struct kstat
*stat
, struct stat64 __user
*statbuf
)
434 INIT_STRUCT_STAT64_PADDING(tmp
);
436 /* mips has weird padding, so we don't get 64 bits there */
437 tmp
.st_dev
= new_encode_dev(stat
->dev
);
438 tmp
.st_rdev
= new_encode_dev(stat
->rdev
);
440 tmp
.st_dev
= huge_encode_dev(stat
->dev
);
441 tmp
.st_rdev
= huge_encode_dev(stat
->rdev
);
443 tmp
.st_ino
= stat
->ino
;
444 if (sizeof(tmp
.st_ino
) < sizeof(stat
->ino
) && tmp
.st_ino
!= stat
->ino
)
446 #ifdef STAT64_HAS_BROKEN_ST_INO
447 tmp
.__st_ino
= stat
->ino
;
449 tmp
.st_mode
= stat
->mode
;
450 tmp
.st_nlink
= stat
->nlink
;
451 tmp
.st_uid
= from_kuid_munged(current_user_ns(), stat
->uid
);
452 tmp
.st_gid
= from_kgid_munged(current_user_ns(), stat
->gid
);
453 tmp
.st_atime
= stat
->atime
.tv_sec
;
454 tmp
.st_atime_nsec
= stat
->atime
.tv_nsec
;
455 tmp
.st_mtime
= stat
->mtime
.tv_sec
;
456 tmp
.st_mtime_nsec
= stat
->mtime
.tv_nsec
;
457 tmp
.st_ctime
= stat
->ctime
.tv_sec
;
458 tmp
.st_ctime_nsec
= stat
->ctime
.tv_nsec
;
459 tmp
.st_size
= stat
->size
;
460 tmp
.st_blocks
= stat
->blocks
;
461 tmp
.st_blksize
= stat
->blksize
;
462 return copy_to_user(statbuf
,&tmp
,sizeof(tmp
)) ? -EFAULT
: 0;
465 SYSCALL_DEFINE2(stat64
, const char __user
*, filename
,
466 struct stat64 __user
*, statbuf
)
469 int error
= vfs_stat(filename
, &stat
);
472 error
= cp_new_stat64(&stat
, statbuf
);
477 SYSCALL_DEFINE2(lstat64
, const char __user
*, filename
,
478 struct stat64 __user
*, statbuf
)
481 int error
= vfs_lstat(filename
, &stat
);
484 error
= cp_new_stat64(&stat
, statbuf
);
489 SYSCALL_DEFINE2(fstat64
, unsigned long, fd
, struct stat64 __user
*, statbuf
)
492 int error
= vfs_fstat(fd
, &stat
);
495 error
= cp_new_stat64(&stat
, statbuf
);
500 SYSCALL_DEFINE4(fstatat64
, int, dfd
, const char __user
*, filename
,
501 struct stat64 __user
*, statbuf
, int, flag
)
506 error
= vfs_fstatat(dfd
, filename
, &stat
, flag
);
509 return cp_new_stat64(&stat
, statbuf
);
511 #endif /* __ARCH_WANT_STAT64 || __ARCH_WANT_COMPAT_STAT64 */
513 static noinline_for_stack
int
514 cp_statx(const struct kstat
*stat
, struct statx __user
*buffer
)
518 memset(&tmp
, 0, sizeof(tmp
));
520 tmp
.stx_mask
= stat
->result_mask
;
521 tmp
.stx_blksize
= stat
->blksize
;
522 tmp
.stx_attributes
= stat
->attributes
;
523 tmp
.stx_nlink
= stat
->nlink
;
524 tmp
.stx_uid
= from_kuid_munged(current_user_ns(), stat
->uid
);
525 tmp
.stx_gid
= from_kgid_munged(current_user_ns(), stat
->gid
);
526 tmp
.stx_mode
= stat
->mode
;
527 tmp
.stx_ino
= stat
->ino
;
528 tmp
.stx_size
= stat
->size
;
529 tmp
.stx_blocks
= stat
->blocks
;
530 tmp
.stx_attributes_mask
= stat
->attributes_mask
;
531 tmp
.stx_atime
.tv_sec
= stat
->atime
.tv_sec
;
532 tmp
.stx_atime
.tv_nsec
= stat
->atime
.tv_nsec
;
533 tmp
.stx_btime
.tv_sec
= stat
->btime
.tv_sec
;
534 tmp
.stx_btime
.tv_nsec
= stat
->btime
.tv_nsec
;
535 tmp
.stx_ctime
.tv_sec
= stat
->ctime
.tv_sec
;
536 tmp
.stx_ctime
.tv_nsec
= stat
->ctime
.tv_nsec
;
537 tmp
.stx_mtime
.tv_sec
= stat
->mtime
.tv_sec
;
538 tmp
.stx_mtime
.tv_nsec
= stat
->mtime
.tv_nsec
;
539 tmp
.stx_rdev_major
= MAJOR(stat
->rdev
);
540 tmp
.stx_rdev_minor
= MINOR(stat
->rdev
);
541 tmp
.stx_dev_major
= MAJOR(stat
->dev
);
542 tmp
.stx_dev_minor
= MINOR(stat
->dev
);
544 return copy_to_user(buffer
, &tmp
, sizeof(tmp
)) ? -EFAULT
: 0;
548 * sys_statx - System call to get enhanced stats
549 * @dfd: Base directory to pathwalk from *or* fd to stat.
550 * @filename: File to stat *or* NULL.
551 * @flags: AT_* flags to control pathwalk.
552 * @mask: Parts of statx struct actually required.
553 * @buffer: Result buffer.
555 * Note that if filename is NULL, then it does the equivalent of fstat() using
556 * dfd to indicate the file of interest.
558 SYSCALL_DEFINE5(statx
,
559 int, dfd
, const char __user
*, filename
, unsigned, flags
,
561 struct statx __user
*, buffer
)
566 if (mask
& STATX__RESERVED
)
568 if ((flags
& AT_STATX_SYNC_TYPE
) == AT_STATX_SYNC_TYPE
)
572 error
= vfs_statx(dfd
, filename
, flags
, &stat
, mask
);
574 error
= vfs_statx_fd(dfd
, &stat
, mask
, flags
);
578 return cp_statx(&stat
, buffer
);
581 /* Caller is here responsible for sufficient locking (ie. inode->i_lock) */
582 void __inode_add_bytes(struct inode
*inode
, loff_t bytes
)
584 inode
->i_blocks
+= bytes
>> 9;
586 inode
->i_bytes
+= bytes
;
587 if (inode
->i_bytes
>= 512) {
589 inode
->i_bytes
-= 512;
593 void inode_add_bytes(struct inode
*inode
, loff_t bytes
)
595 spin_lock(&inode
->i_lock
);
596 __inode_add_bytes(inode
, bytes
);
597 spin_unlock(&inode
->i_lock
);
600 EXPORT_SYMBOL(inode_add_bytes
);
602 void __inode_sub_bytes(struct inode
*inode
, loff_t bytes
)
604 inode
->i_blocks
-= bytes
>> 9;
606 if (inode
->i_bytes
< bytes
) {
608 inode
->i_bytes
+= 512;
610 inode
->i_bytes
-= bytes
;
613 EXPORT_SYMBOL(__inode_sub_bytes
);
615 void inode_sub_bytes(struct inode
*inode
, loff_t bytes
)
617 spin_lock(&inode
->i_lock
);
618 __inode_sub_bytes(inode
, bytes
);
619 spin_unlock(&inode
->i_lock
);
622 EXPORT_SYMBOL(inode_sub_bytes
);
624 loff_t
inode_get_bytes(struct inode
*inode
)
628 spin_lock(&inode
->i_lock
);
629 ret
= (((loff_t
)inode
->i_blocks
) << 9) + inode
->i_bytes
;
630 spin_unlock(&inode
->i_lock
);
634 EXPORT_SYMBOL(inode_get_bytes
);
636 void inode_set_bytes(struct inode
*inode
, loff_t bytes
)
638 /* Caller is here responsible for sufficient locking
639 * (ie. inode->i_lock) */
640 inode
->i_blocks
= bytes
>> 9;
641 inode
->i_bytes
= bytes
& 511;
644 EXPORT_SYMBOL(inode_set_bytes
);