Commit | Line | Data |
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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 LT |
2 | /* |
3 | * linux/fs/stat.c | |
4 | * | |
5 | * Copyright (C) 1991, 1992 Linus Torvalds | |
6 | */ | |
7 | ||
2d985f8c | 8 | #include <linux/blkdev.h> |
630d9c47 | 9 | #include <linux/export.h> |
1da177e4 LT |
10 | #include <linux/mm.h> |
11 | #include <linux/errno.h> | |
12 | #include <linux/file.h> | |
1da177e4 LT |
13 | #include <linux/highuid.h> |
14 | #include <linux/fs.h> | |
15 | #include <linux/namei.h> | |
16 | #include <linux/security.h> | |
5b825c3a | 17 | #include <linux/cred.h> |
1da177e4 | 18 | #include <linux/syscalls.h> |
ba52de12 | 19 | #include <linux/pagemap.h> |
ac565de3 | 20 | #include <linux/compat.h> |
a1175d6b | 21 | #include <linux/iversion.h> |
1da177e4 | 22 | |
7c0f6ba6 | 23 | #include <linux/uaccess.h> |
1da177e4 LT |
24 | #include <asm/unistd.h> |
25 | ||
3934e36f | 26 | #include "internal.h" |
fa2fcf4f | 27 | #include "mount.h" |
3934e36f | 28 | |
a528d35e DH |
29 | /** |
30 | * generic_fillattr - Fill in the basic attributes from the inode struct | |
0d72b928 JL |
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 | |
a528d35e DH |
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. | |
0d56a451 | 39 | * |
b74d24f7 CB |
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 | |
0d56a451 | 43 | * uid and gid filds. On non-idmapped mounts or if permission checking is to be |
b74d24f7 | 44 | * performed on the raw inode simply passs @nop_mnt_idmap. |
a528d35e | 45 | */ |
0d72b928 JL |
46 | void generic_fillattr(struct mnt_idmap *idmap, u32 request_mask, |
47 | struct inode *inode, struct kstat *stat) | |
1da177e4 | 48 | { |
e67fe633 CB |
49 | vfsuid_t vfsuid = i_uid_into_vfsuid(idmap, inode); |
50 | vfsgid_t vfsgid = i_gid_into_vfsgid(idmap, inode); | |
a2bd096f | 51 | |
1da177e4 LT |
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; | |
a2bd096f CB |
56 | stat->uid = vfsuid_into_kuid(vfsuid); |
57 | stat->gid = vfsgid_into_kgid(vfsgid); | |
1da177e4 | 58 | stat->rdev = inode->i_rdev; |
3ddcd056 | 59 | stat->size = i_size_read(inode); |
16a94965 JL |
60 | stat->atime = inode_get_atime(inode); |
61 | stat->mtime = inode_get_mtime(inode); | |
647aa768 | 62 | stat->ctime = inode_get_ctime(inode); |
93407472 | 63 | stat->blksize = i_blocksize(inode); |
3ddcd056 | 64 | stat->blocks = inode->i_blocks; |
0d72b928 JL |
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 | ||
a528d35e | 71 | } |
1da177e4 LT |
72 | EXPORT_SYMBOL(generic_fillattr); |
73 | ||
4f911138 AG |
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 | ||
b7a6ec52 BF |
92 | /** |
93 | * vfs_getattr_nosec - getattr without security checks | |
94 | * @path: file to get attributes from | |
95 | * @stat: structure to return attributes in | |
a528d35e | 96 | * @request_mask: STATX_xxx flags indicating what the caller wants |
f2d077ff | 97 | * @query_flags: Query mode (AT_STATX_SYNC_TYPE) |
b7a6ec52 BF |
98 | * |
99 | * Get attributes without calling security_inode_getattr. | |
100 | * | |
101 | * Currently the only caller other than vfs_getattr is internal to the | |
a528d35e DH |
102 | * filehandle lookup code, which uses only the inode number and returns no |
103 | * attributes to any user. Any other code probably wants vfs_getattr. | |
b7a6ec52 | 104 | */ |
a528d35e DH |
105 | int vfs_getattr_nosec(const struct path *path, struct kstat *stat, |
106 | u32 request_mask, unsigned int query_flags) | |
1da177e4 | 107 | { |
b74d24f7 | 108 | struct mnt_idmap *idmap; |
bb668734 | 109 | struct inode *inode = d_backing_inode(path->dentry); |
1da177e4 | 110 | |
a528d35e DH |
111 | memset(stat, 0, sizeof(*stat)); |
112 | stat->result_mask |= STATX_BASIC_STATS; | |
f2d077ff | 113 | query_flags &= AT_STATX_SYNC_TYPE; |
801e5237 CH |
114 | |
115 | /* allow the fs to override these if it really wants to */ | |
761e28fa MS |
116 | /* SB_NOATIME means filesystem supplies dummy atime value */ |
117 | if (inode->i_sb->s_flags & SB_NOATIME) | |
801e5237 | 118 | stat->result_mask &= ~STATX_ATIME; |
5afa7e8b TT |
119 | |
120 | /* | |
121 | * Note: If you add another clause to set an attribute flag, please | |
122 | * update attributes_mask below. | |
123 | */ | |
801e5237 CH |
124 | if (IS_AUTOMOUNT(inode)) |
125 | stat->attributes |= STATX_ATTR_AUTOMOUNT; | |
126 | ||
712b2698 IW |
127 | if (IS_DAX(inode)) |
128 | stat->attributes |= STATX_ATTR_DAX; | |
129 | ||
5afa7e8b TT |
130 | stat->attributes_mask |= (STATX_ATTR_AUTOMOUNT | |
131 | STATX_ATTR_DAX); | |
132 | ||
b74d24f7 | 133 | idmap = mnt_idmap(path->mnt); |
1da177e4 | 134 | if (inode->i_op->getattr) |
b74d24f7 | 135 | return inode->i_op->getattr(idmap, path, stat, |
549c7297 | 136 | request_mask, query_flags); |
1da177e4 | 137 | |
0d72b928 | 138 | generic_fillattr(idmap, request_mask, inode, stat); |
1da177e4 LT |
139 | return 0; |
140 | } | |
b7a6ec52 BF |
141 | EXPORT_SYMBOL(vfs_getattr_nosec); |
142 | ||
a528d35e DH |
143 | /* |
144 | * vfs_getattr - Get the enhanced basic attributes of a file | |
145 | * @path: The file of interest | |
146 | * @stat: Where to return the statistics | |
147 | * @request_mask: STATX_xxx flags indicating what the caller wants | |
f2d077ff | 148 | * @query_flags: Query mode (AT_STATX_SYNC_TYPE) |
a528d35e DH |
149 | * |
150 | * Ask the filesystem for a file's attributes. The caller must indicate in | |
151 | * request_mask and query_flags to indicate what they want. | |
152 | * | |
153 | * If the file is remote, the filesystem can be forced to update the attributes | |
154 | * from the backing store by passing AT_STATX_FORCE_SYNC in query_flags or can | |
155 | * suppress the update by passing AT_STATX_DONT_SYNC. | |
156 | * | |
157 | * Bits must have been set in request_mask to indicate which attributes the | |
158 | * caller wants retrieving. Any such attribute not requested may be returned | |
159 | * anyway, but the value may be approximate, and, if remote, may not have been | |
160 | * synchronised with the server. | |
161 | * | |
162 | * 0 will be returned on success, and a -ve error code if unsuccessful. | |
163 | */ | |
164 | int vfs_getattr(const struct path *path, struct kstat *stat, | |
165 | u32 request_mask, unsigned int query_flags) | |
b7a6ec52 BF |
166 | { |
167 | int retval; | |
168 | ||
3f7036a0 | 169 | retval = security_inode_getattr(path); |
b7a6ec52 BF |
170 | if (retval) |
171 | return retval; | |
a528d35e | 172 | return vfs_getattr_nosec(path, stat, request_mask, query_flags); |
b7a6ec52 | 173 | } |
1da177e4 LT |
174 | EXPORT_SYMBOL(vfs_getattr); |
175 | ||
a528d35e | 176 | /** |
da9aa5d9 | 177 | * vfs_fstat - Get the basic attributes by file descriptor |
a528d35e DH |
178 | * @fd: The file descriptor referring to the file of interest |
179 | * @stat: The result structure to fill in. | |
a528d35e DH |
180 | * |
181 | * This function is a wrapper around vfs_getattr(). The main difference is | |
182 | * that it uses a file descriptor to determine the file location. | |
183 | * | |
184 | * 0 will be returned on success, and a -ve error code if unsuccessful. | |
185 | */ | |
da9aa5d9 | 186 | int vfs_fstat(int fd, struct kstat *stat) |
1da177e4 | 187 | { |
8c7493aa | 188 | struct fd f; |
da9aa5d9 | 189 | int error; |
8c7493aa EB |
190 | |
191 | f = fdget_raw(fd); | |
da9aa5d9 CH |
192 | if (!f.file) |
193 | return -EBADF; | |
194 | error = vfs_getattr(&f.file->f_path, stat, STATX_BASIC_STATS, 0); | |
195 | fdput(f); | |
1da177e4 LT |
196 | return error; |
197 | } | |
1da177e4 | 198 | |
1b6fe6e0 SR |
199 | int getname_statx_lookup_flags(int flags) |
200 | { | |
201 | int lookup_flags = 0; | |
202 | ||
203 | if (!(flags & AT_SYMLINK_NOFOLLOW)) | |
204 | lookup_flags |= LOOKUP_FOLLOW; | |
205 | if (!(flags & AT_NO_AUTOMOUNT)) | |
206 | lookup_flags |= LOOKUP_AUTOMOUNT; | |
207 | if (flags & AT_EMPTY_PATH) | |
208 | lookup_flags |= LOOKUP_EMPTY; | |
209 | ||
210 | return lookup_flags; | |
211 | } | |
212 | ||
a528d35e DH |
213 | /** |
214 | * vfs_statx - Get basic and extra attributes by filename | |
215 | * @dfd: A file descriptor representing the base dir for a relative filename | |
216 | * @filename: The name of the file of interest | |
217 | * @flags: Flags to control the query | |
218 | * @stat: The result structure to fill in. | |
219 | * @request_mask: STATX_xxx flags indicating what the caller wants | |
220 | * | |
221 | * This function is a wrapper around vfs_getattr(). The main difference is | |
222 | * that it uses a filename and base directory to determine the file location. | |
223 | * Additionally, the use of AT_SYMLINK_NOFOLLOW in flags will prevent a symlink | |
224 | * at the given name from being referenced. | |
225 | * | |
a528d35e DH |
226 | * 0 will be returned on success, and a -ve error code if unsuccessful. |
227 | */ | |
1b6fe6e0 | 228 | static int vfs_statx(int dfd, struct filename *filename, int flags, |
a528d35e | 229 | struct kstat *stat, u32 request_mask) |
0112fc22 | 230 | { |
2eae7a18 | 231 | struct path path; |
1b6fe6e0 | 232 | unsigned int lookup_flags = getname_statx_lookup_flags(flags); |
b3f05150 | 233 | int error; |
0112fc22 | 234 | |
b3f05150 | 235 | if (flags & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT | AT_EMPTY_PATH | |
f2d077ff | 236 | AT_STATX_SYNC_TYPE)) |
a528d35e | 237 | return -EINVAL; |
b3f05150 | 238 | |
836fb7e7 | 239 | retry: |
1b6fe6e0 | 240 | error = filename_lookup(dfd, filename, lookup_flags, &path, NULL); |
2eae7a18 CH |
241 | if (error) |
242 | goto out; | |
243 | ||
a528d35e | 244 | error = vfs_getattr(&path, stat, request_mask, flags); |
2d985f8c | 245 | |
fa2fcf4f MS |
246 | stat->mnt_id = real_mount(path.mnt)->mnt_id; |
247 | stat->result_mask |= STATX_MNT_ID; | |
2d985f8c | 248 | |
80340fe3 MS |
249 | if (path.mnt->mnt_root == path.dentry) |
250 | stat->attributes |= STATX_ATTR_MOUNT_ROOT; | |
251 | stat->attributes_mask |= STATX_ATTR_MOUNT_ROOT; | |
2d985f8c EB |
252 | |
253 | /* Handle STATX_DIOALIGN for block devices. */ | |
254 | if (request_mask & STATX_DIOALIGN) { | |
255 | struct inode *inode = d_backing_inode(path.dentry); | |
256 | ||
257 | if (S_ISBLK(inode->i_mode)) | |
258 | bdev_statx_dioalign(inode, stat); | |
259 | } | |
260 | ||
2eae7a18 | 261 | path_put(&path); |
836fb7e7 JL |
262 | if (retry_estale(error, lookup_flags)) { |
263 | lookup_flags |= LOOKUP_REVAL; | |
264 | goto retry; | |
265 | } | |
0112fc22 OD |
266 | out: |
267 | return error; | |
268 | } | |
2eae7a18 | 269 | |
09f1bde4 CH |
270 | int vfs_fstatat(int dfd, const char __user *filename, |
271 | struct kstat *stat, int flags) | |
272 | { | |
1b6fe6e0 SR |
273 | int ret; |
274 | int statx_flags = flags | AT_NO_AUTOMOUNT; | |
275 | struct filename *name; | |
276 | ||
9013c51c LT |
277 | /* |
278 | * Work around glibc turning fstat() into fstatat(AT_EMPTY_PATH) | |
279 | * | |
280 | * If AT_EMPTY_PATH is set, we expect the common case to be that | |
281 | * empty path, and avoid doing all the extra pathname work. | |
282 | */ | |
283 | if (dfd >= 0 && flags == AT_EMPTY_PATH) { | |
284 | char c; | |
285 | ||
286 | ret = get_user(c, filename); | |
287 | if (unlikely(ret)) | |
288 | return ret; | |
289 | ||
290 | if (likely(!c)) | |
291 | return vfs_fstat(dfd, stat); | |
292 | } | |
293 | ||
1b6fe6e0 SR |
294 | name = getname_flags(filename, getname_statx_lookup_flags(statx_flags), NULL); |
295 | ret = vfs_statx(dfd, name, statx_flags, stat, STATX_BASIC_STATS); | |
296 | putname(name); | |
297 | ||
298 | return ret; | |
09f1bde4 | 299 | } |
0112fc22 | 300 | |
1da177e4 LT |
301 | #ifdef __ARCH_WANT_OLD_STAT |
302 | ||
303 | /* | |
304 | * For backward compatibility? Maybe this should be moved | |
305 | * into arch/i386 instead? | |
306 | */ | |
307 | static int cp_old_stat(struct kstat *stat, struct __old_kernel_stat __user * statbuf) | |
308 | { | |
309 | static int warncount = 5; | |
310 | struct __old_kernel_stat tmp; | |
a528d35e | 311 | |
1da177e4 LT |
312 | if (warncount > 0) { |
313 | warncount--; | |
314 | printk(KERN_WARNING "VFS: Warning: %s using old stat() call. Recompile your binary.\n", | |
315 | current->comm); | |
316 | } else if (warncount < 0) { | |
317 | /* it's laughable, but... */ | |
318 | warncount = 0; | |
319 | } | |
320 | ||
321 | memset(&tmp, 0, sizeof(struct __old_kernel_stat)); | |
322 | tmp.st_dev = old_encode_dev(stat->dev); | |
323 | tmp.st_ino = stat->ino; | |
afefdbb2 DH |
324 | if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino) |
325 | return -EOVERFLOW; | |
1da177e4 LT |
326 | tmp.st_mode = stat->mode; |
327 | tmp.st_nlink = stat->nlink; | |
328 | if (tmp.st_nlink != stat->nlink) | |
329 | return -EOVERFLOW; | |
a7c1938e EB |
330 | SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid)); |
331 | SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid)); | |
1da177e4 LT |
332 | tmp.st_rdev = old_encode_dev(stat->rdev); |
333 | #if BITS_PER_LONG == 32 | |
334 | if (stat->size > MAX_NON_LFS) | |
335 | return -EOVERFLOW; | |
a528d35e | 336 | #endif |
1da177e4 LT |
337 | tmp.st_size = stat->size; |
338 | tmp.st_atime = stat->atime.tv_sec; | |
339 | tmp.st_mtime = stat->mtime.tv_sec; | |
340 | tmp.st_ctime = stat->ctime.tv_sec; | |
341 | return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0; | |
342 | } | |
343 | ||
c7887325 DH |
344 | SYSCALL_DEFINE2(stat, const char __user *, filename, |
345 | struct __old_kernel_stat __user *, statbuf) | |
1da177e4 LT |
346 | { |
347 | struct kstat stat; | |
2eae7a18 | 348 | int error; |
1da177e4 | 349 | |
2eae7a18 CH |
350 | error = vfs_stat(filename, &stat); |
351 | if (error) | |
352 | return error; | |
1da177e4 | 353 | |
2eae7a18 | 354 | return cp_old_stat(&stat, statbuf); |
1da177e4 | 355 | } |
257ac264 | 356 | |
c7887325 DH |
357 | SYSCALL_DEFINE2(lstat, const char __user *, filename, |
358 | struct __old_kernel_stat __user *, statbuf) | |
1da177e4 LT |
359 | { |
360 | struct kstat stat; | |
2eae7a18 | 361 | int error; |
1da177e4 | 362 | |
2eae7a18 CH |
363 | error = vfs_lstat(filename, &stat); |
364 | if (error) | |
365 | return error; | |
1da177e4 | 366 | |
2eae7a18 | 367 | return cp_old_stat(&stat, statbuf); |
1da177e4 | 368 | } |
257ac264 HC |
369 | |
370 | SYSCALL_DEFINE2(fstat, unsigned int, fd, struct __old_kernel_stat __user *, statbuf) | |
1da177e4 LT |
371 | { |
372 | struct kstat stat; | |
373 | int error = vfs_fstat(fd, &stat); | |
374 | ||
375 | if (!error) | |
376 | error = cp_old_stat(&stat, statbuf); | |
377 | ||
378 | return error; | |
379 | } | |
380 | ||
381 | #endif /* __ARCH_WANT_OLD_STAT */ | |
382 | ||
82b355d1 AB |
383 | #ifdef __ARCH_WANT_NEW_STAT |
384 | ||
8529f613 LT |
385 | #ifndef INIT_STRUCT_STAT_PADDING |
386 | # define INIT_STRUCT_STAT_PADDING(st) memset(&st, 0, sizeof(st)) | |
387 | #endif | |
388 | ||
1da177e4 LT |
389 | static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf) |
390 | { | |
391 | struct stat tmp; | |
392 | ||
932aba1e MP |
393 | if (sizeof(tmp.st_dev) < 4 && !old_valid_dev(stat->dev)) |
394 | return -EOVERFLOW; | |
395 | if (sizeof(tmp.st_rdev) < 4 && !old_valid_dev(stat->rdev)) | |
1da177e4 | 396 | return -EOVERFLOW; |
a52dd971 LT |
397 | #if BITS_PER_LONG == 32 |
398 | if (stat->size > MAX_NON_LFS) | |
1da177e4 LT |
399 | return -EOVERFLOW; |
400 | #endif | |
401 | ||
8529f613 | 402 | INIT_STRUCT_STAT_PADDING(tmp); |
932aba1e | 403 | tmp.st_dev = new_encode_dev(stat->dev); |
1da177e4 | 404 | tmp.st_ino = stat->ino; |
afefdbb2 DH |
405 | if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino) |
406 | return -EOVERFLOW; | |
1da177e4 LT |
407 | tmp.st_mode = stat->mode; |
408 | tmp.st_nlink = stat->nlink; | |
409 | if (tmp.st_nlink != stat->nlink) | |
410 | return -EOVERFLOW; | |
a7c1938e EB |
411 | SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid)); |
412 | SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid)); | |
932aba1e | 413 | tmp.st_rdev = new_encode_dev(stat->rdev); |
1da177e4 LT |
414 | tmp.st_size = stat->size; |
415 | tmp.st_atime = stat->atime.tv_sec; | |
416 | tmp.st_mtime = stat->mtime.tv_sec; | |
417 | tmp.st_ctime = stat->ctime.tv_sec; | |
418 | #ifdef STAT_HAVE_NSEC | |
419 | tmp.st_atime_nsec = stat->atime.tv_nsec; | |
420 | tmp.st_mtime_nsec = stat->mtime.tv_nsec; | |
421 | tmp.st_ctime_nsec = stat->ctime.tv_nsec; | |
422 | #endif | |
423 | tmp.st_blocks = stat->blocks; | |
424 | tmp.st_blksize = stat->blksize; | |
425 | return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0; | |
426 | } | |
427 | ||
c7887325 DH |
428 | SYSCALL_DEFINE2(newstat, const char __user *, filename, |
429 | struct stat __user *, statbuf) | |
5590ff0d UD |
430 | { |
431 | struct kstat stat; | |
2eae7a18 | 432 | int error = vfs_stat(filename, &stat); |
5590ff0d | 433 | |
2eae7a18 CH |
434 | if (error) |
435 | return error; | |
436 | return cp_new_stat(&stat, statbuf); | |
5590ff0d UD |
437 | } |
438 | ||
c7887325 DH |
439 | SYSCALL_DEFINE2(newlstat, const char __user *, filename, |
440 | struct stat __user *, statbuf) | |
1da177e4 LT |
441 | { |
442 | struct kstat stat; | |
2eae7a18 | 443 | int error; |
1da177e4 | 444 | |
2eae7a18 CH |
445 | error = vfs_lstat(filename, &stat); |
446 | if (error) | |
447 | return error; | |
1da177e4 | 448 | |
2eae7a18 | 449 | return cp_new_stat(&stat, statbuf); |
1da177e4 | 450 | } |
5590ff0d | 451 | |
2833c28a | 452 | #if !defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_SYS_NEWFSTATAT) |
c7887325 | 453 | SYSCALL_DEFINE4(newfstatat, int, dfd, const char __user *, filename, |
6559eed8 | 454 | struct stat __user *, statbuf, int, flag) |
1da177e4 LT |
455 | { |
456 | struct kstat stat; | |
0112fc22 | 457 | int error; |
1da177e4 | 458 | |
0112fc22 OD |
459 | error = vfs_fstatat(dfd, filename, &stat, flag); |
460 | if (error) | |
461 | return error; | |
462 | return cp_new_stat(&stat, statbuf); | |
1da177e4 | 463 | } |
cff2b760 | 464 | #endif |
5590ff0d | 465 | |
257ac264 | 466 | SYSCALL_DEFINE2(newfstat, unsigned int, fd, struct stat __user *, statbuf) |
1da177e4 LT |
467 | { |
468 | struct kstat stat; | |
469 | int error = vfs_fstat(fd, &stat); | |
470 | ||
471 | if (!error) | |
472 | error = cp_new_stat(&stat, statbuf); | |
473 | ||
474 | return error; | |
475 | } | |
82b355d1 | 476 | #endif |
1da177e4 | 477 | |
2dae0248 DB |
478 | static int do_readlinkat(int dfd, const char __user *pathname, |
479 | char __user *buf, int bufsiz) | |
1da177e4 | 480 | { |
2d8f3038 | 481 | struct path path; |
1da177e4 | 482 | int error; |
1fa1e7f6 | 483 | int empty = 0; |
7955119e | 484 | unsigned int lookup_flags = LOOKUP_EMPTY; |
1da177e4 LT |
485 | |
486 | if (bufsiz <= 0) | |
487 | return -EINVAL; | |
488 | ||
7955119e JL |
489 | retry: |
490 | error = user_path_at_empty(dfd, pathname, lookup_flags, &path, &empty); | |
1da177e4 | 491 | if (!error) { |
bb668734 | 492 | struct inode *inode = d_backing_inode(path.dentry); |
1da177e4 | 493 | |
1fa1e7f6 | 494 | error = empty ? -ENOENT : -EINVAL; |
fd4a0edf MS |
495 | /* |
496 | * AFS mountpoints allow readlink(2) but are not symlinks | |
497 | */ | |
498 | if (d_is_symlink(path.dentry) || inode->i_op->readlink) { | |
2d8f3038 | 499 | error = security_inode_readlink(path.dentry); |
1da177e4 | 500 | if (!error) { |
68ac1234 | 501 | touch_atime(&path); |
fd4a0edf | 502 | error = vfs_readlink(path.dentry, buf, bufsiz); |
1da177e4 LT |
503 | } |
504 | } | |
2d8f3038 | 505 | path_put(&path); |
7955119e JL |
506 | if (retry_estale(error, lookup_flags)) { |
507 | lookup_flags |= LOOKUP_REVAL; | |
508 | goto retry; | |
509 | } | |
1da177e4 LT |
510 | } |
511 | return error; | |
512 | } | |
513 | ||
2dae0248 DB |
514 | SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname, |
515 | char __user *, buf, int, bufsiz) | |
516 | { | |
517 | return do_readlinkat(dfd, pathname, buf, bufsiz); | |
518 | } | |
519 | ||
002c8976 HC |
520 | SYSCALL_DEFINE3(readlink, const char __user *, path, char __user *, buf, |
521 | int, bufsiz) | |
5590ff0d | 522 | { |
2dae0248 | 523 | return do_readlinkat(AT_FDCWD, path, buf, bufsiz); |
5590ff0d UD |
524 | } |
525 | ||
1da177e4 LT |
526 | |
527 | /* ---------- LFS-64 ----------- */ | |
0753f70f | 528 | #if defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_COMPAT_STAT64) |
1da177e4 | 529 | |
8529f613 LT |
530 | #ifndef INIT_STRUCT_STAT64_PADDING |
531 | # define INIT_STRUCT_STAT64_PADDING(st) memset(&st, 0, sizeof(st)) | |
532 | #endif | |
533 | ||
1da177e4 LT |
534 | static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf) |
535 | { | |
536 | struct stat64 tmp; | |
537 | ||
8529f613 | 538 | INIT_STRUCT_STAT64_PADDING(tmp); |
1da177e4 LT |
539 | #ifdef CONFIG_MIPS |
540 | /* mips has weird padding, so we don't get 64 bits there */ | |
1da177e4 LT |
541 | tmp.st_dev = new_encode_dev(stat->dev); |
542 | tmp.st_rdev = new_encode_dev(stat->rdev); | |
543 | #else | |
544 | tmp.st_dev = huge_encode_dev(stat->dev); | |
545 | tmp.st_rdev = huge_encode_dev(stat->rdev); | |
546 | #endif | |
547 | tmp.st_ino = stat->ino; | |
afefdbb2 DH |
548 | if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino) |
549 | return -EOVERFLOW; | |
1da177e4 LT |
550 | #ifdef STAT64_HAS_BROKEN_ST_INO |
551 | tmp.__st_ino = stat->ino; | |
552 | #endif | |
553 | tmp.st_mode = stat->mode; | |
554 | tmp.st_nlink = stat->nlink; | |
a7c1938e EB |
555 | tmp.st_uid = from_kuid_munged(current_user_ns(), stat->uid); |
556 | tmp.st_gid = from_kgid_munged(current_user_ns(), stat->gid); | |
1da177e4 LT |
557 | tmp.st_atime = stat->atime.tv_sec; |
558 | tmp.st_atime_nsec = stat->atime.tv_nsec; | |
559 | tmp.st_mtime = stat->mtime.tv_sec; | |
560 | tmp.st_mtime_nsec = stat->mtime.tv_nsec; | |
561 | tmp.st_ctime = stat->ctime.tv_sec; | |
562 | tmp.st_ctime_nsec = stat->ctime.tv_nsec; | |
563 | tmp.st_size = stat->size; | |
564 | tmp.st_blocks = stat->blocks; | |
565 | tmp.st_blksize = stat->blksize; | |
566 | return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0; | |
567 | } | |
568 | ||
c7887325 DH |
569 | SYSCALL_DEFINE2(stat64, const char __user *, filename, |
570 | struct stat64 __user *, statbuf) | |
1da177e4 LT |
571 | { |
572 | struct kstat stat; | |
573 | int error = vfs_stat(filename, &stat); | |
574 | ||
575 | if (!error) | |
576 | error = cp_new_stat64(&stat, statbuf); | |
577 | ||
578 | return error; | |
579 | } | |
257ac264 | 580 | |
c7887325 DH |
581 | SYSCALL_DEFINE2(lstat64, const char __user *, filename, |
582 | struct stat64 __user *, statbuf) | |
1da177e4 LT |
583 | { |
584 | struct kstat stat; | |
585 | int error = vfs_lstat(filename, &stat); | |
586 | ||
587 | if (!error) | |
588 | error = cp_new_stat64(&stat, statbuf); | |
589 | ||
590 | return error; | |
591 | } | |
257ac264 HC |
592 | |
593 | SYSCALL_DEFINE2(fstat64, unsigned long, fd, struct stat64 __user *, statbuf) | |
1da177e4 LT |
594 | { |
595 | struct kstat stat; | |
596 | int error = vfs_fstat(fd, &stat); | |
597 | ||
598 | if (!error) | |
599 | error = cp_new_stat64(&stat, statbuf); | |
600 | ||
601 | return error; | |
602 | } | |
603 | ||
c7887325 | 604 | SYSCALL_DEFINE4(fstatat64, int, dfd, const char __user *, filename, |
6559eed8 | 605 | struct stat64 __user *, statbuf, int, flag) |
cff2b760 UD |
606 | { |
607 | struct kstat stat; | |
0112fc22 | 608 | int error; |
cff2b760 | 609 | |
0112fc22 OD |
610 | error = vfs_fstatat(dfd, filename, &stat, flag); |
611 | if (error) | |
612 | return error; | |
613 | return cp_new_stat64(&stat, statbuf); | |
cff2b760 | 614 | } |
0753f70f | 615 | #endif /* __ARCH_WANT_STAT64 || __ARCH_WANT_COMPAT_STAT64 */ |
1da177e4 | 616 | |
6f88cc17 | 617 | static noinline_for_stack int |
64bd7204 | 618 | cp_statx(const struct kstat *stat, struct statx __user *buffer) |
a528d35e | 619 | { |
64bd7204 EB |
620 | struct statx tmp; |
621 | ||
622 | memset(&tmp, 0, sizeof(tmp)); | |
623 | ||
a1175d6b JL |
624 | /* STATX_CHANGE_COOKIE is kernel-only for now */ |
625 | tmp.stx_mask = stat->result_mask & ~STATX_CHANGE_COOKIE; | |
64bd7204 | 626 | tmp.stx_blksize = stat->blksize; |
a1175d6b JL |
627 | /* STATX_ATTR_CHANGE_MONOTONIC is kernel-only for now */ |
628 | tmp.stx_attributes = stat->attributes & ~STATX_ATTR_CHANGE_MONOTONIC; | |
64bd7204 EB |
629 | tmp.stx_nlink = stat->nlink; |
630 | tmp.stx_uid = from_kuid_munged(current_user_ns(), stat->uid); | |
631 | tmp.stx_gid = from_kgid_munged(current_user_ns(), stat->gid); | |
632 | tmp.stx_mode = stat->mode; | |
633 | tmp.stx_ino = stat->ino; | |
634 | tmp.stx_size = stat->size; | |
635 | tmp.stx_blocks = stat->blocks; | |
3209f68b | 636 | tmp.stx_attributes_mask = stat->attributes_mask; |
64bd7204 EB |
637 | tmp.stx_atime.tv_sec = stat->atime.tv_sec; |
638 | tmp.stx_atime.tv_nsec = stat->atime.tv_nsec; | |
639 | tmp.stx_btime.tv_sec = stat->btime.tv_sec; | |
640 | tmp.stx_btime.tv_nsec = stat->btime.tv_nsec; | |
641 | tmp.stx_ctime.tv_sec = stat->ctime.tv_sec; | |
642 | tmp.stx_ctime.tv_nsec = stat->ctime.tv_nsec; | |
643 | tmp.stx_mtime.tv_sec = stat->mtime.tv_sec; | |
644 | tmp.stx_mtime.tv_nsec = stat->mtime.tv_nsec; | |
645 | tmp.stx_rdev_major = MAJOR(stat->rdev); | |
646 | tmp.stx_rdev_minor = MINOR(stat->rdev); | |
647 | tmp.stx_dev_major = MAJOR(stat->dev); | |
648 | tmp.stx_dev_minor = MINOR(stat->dev); | |
fa2fcf4f | 649 | tmp.stx_mnt_id = stat->mnt_id; |
825cf206 EB |
650 | tmp.stx_dio_mem_align = stat->dio_mem_align; |
651 | tmp.stx_dio_offset_align = stat->dio_offset_align; | |
64bd7204 EB |
652 | |
653 | return copy_to_user(buffer, &tmp, sizeof(tmp)) ? -EFAULT : 0; | |
a528d35e DH |
654 | } |
655 | ||
1b6fe6e0 | 656 | int do_statx(int dfd, struct filename *filename, unsigned int flags, |
0018784f BM |
657 | unsigned int mask, struct statx __user *buffer) |
658 | { | |
659 | struct kstat stat; | |
660 | int error; | |
661 | ||
662 | if (mask & STATX__RESERVED) | |
663 | return -EINVAL; | |
664 | if ((flags & AT_STATX_SYNC_TYPE) == AT_STATX_SYNC_TYPE) | |
665 | return -EINVAL; | |
666 | ||
a1175d6b JL |
667 | /* STATX_CHANGE_COOKIE is kernel-only for now. Ignore requests |
668 | * from userland. | |
669 | */ | |
670 | mask &= ~STATX_CHANGE_COOKIE; | |
671 | ||
0018784f BM |
672 | error = vfs_statx(dfd, filename, flags, &stat, mask); |
673 | if (error) | |
674 | return error; | |
675 | ||
676 | return cp_statx(&stat, buffer); | |
677 | } | |
678 | ||
a528d35e DH |
679 | /** |
680 | * sys_statx - System call to get enhanced stats | |
681 | * @dfd: Base directory to pathwalk from *or* fd to stat. | |
1e2f82d1 | 682 | * @filename: File to stat or "" with AT_EMPTY_PATH |
a528d35e DH |
683 | * @flags: AT_* flags to control pathwalk. |
684 | * @mask: Parts of statx struct actually required. | |
685 | * @buffer: Result buffer. | |
686 | * | |
1e2f82d1 DH |
687 | * Note that fstat() can be emulated by setting dfd to the fd of interest, |
688 | * supplying "" as the filename and setting AT_EMPTY_PATH in the flags. | |
a528d35e DH |
689 | */ |
690 | SYSCALL_DEFINE5(statx, | |
691 | int, dfd, const char __user *, filename, unsigned, flags, | |
692 | unsigned int, mask, | |
693 | struct statx __user *, buffer) | |
694 | { | |
1b6fe6e0 SR |
695 | int ret; |
696 | struct filename *name; | |
697 | ||
698 | name = getname_flags(filename, getname_statx_lookup_flags(flags), NULL); | |
699 | ret = do_statx(dfd, name, flags, mask, buffer); | |
700 | putname(name); | |
701 | ||
702 | return ret; | |
a528d35e DH |
703 | } |
704 | ||
f18ed30d | 705 | #if defined(CONFIG_COMPAT) && defined(__ARCH_WANT_COMPAT_STAT) |
ac565de3 AV |
706 | static int cp_compat_stat(struct kstat *stat, struct compat_stat __user *ubuf) |
707 | { | |
708 | struct compat_stat tmp; | |
709 | ||
932aba1e MP |
710 | if (sizeof(tmp.st_dev) < 4 && !old_valid_dev(stat->dev)) |
711 | return -EOVERFLOW; | |
712 | if (sizeof(tmp.st_rdev) < 4 && !old_valid_dev(stat->rdev)) | |
ac565de3 AV |
713 | return -EOVERFLOW; |
714 | ||
715 | memset(&tmp, 0, sizeof(tmp)); | |
932aba1e | 716 | tmp.st_dev = new_encode_dev(stat->dev); |
ac565de3 AV |
717 | tmp.st_ino = stat->ino; |
718 | if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino) | |
719 | return -EOVERFLOW; | |
720 | tmp.st_mode = stat->mode; | |
721 | tmp.st_nlink = stat->nlink; | |
722 | if (tmp.st_nlink != stat->nlink) | |
723 | return -EOVERFLOW; | |
724 | SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid)); | |
725 | SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid)); | |
932aba1e | 726 | tmp.st_rdev = new_encode_dev(stat->rdev); |
ac565de3 AV |
727 | if ((u64) stat->size > MAX_NON_LFS) |
728 | return -EOVERFLOW; | |
729 | tmp.st_size = stat->size; | |
730 | tmp.st_atime = stat->atime.tv_sec; | |
731 | tmp.st_atime_nsec = stat->atime.tv_nsec; | |
732 | tmp.st_mtime = stat->mtime.tv_sec; | |
733 | tmp.st_mtime_nsec = stat->mtime.tv_nsec; | |
734 | tmp.st_ctime = stat->ctime.tv_sec; | |
735 | tmp.st_ctime_nsec = stat->ctime.tv_nsec; | |
736 | tmp.st_blocks = stat->blocks; | |
737 | tmp.st_blksize = stat->blksize; | |
738 | return copy_to_user(ubuf, &tmp, sizeof(tmp)) ? -EFAULT : 0; | |
739 | } | |
740 | ||
741 | COMPAT_SYSCALL_DEFINE2(newstat, const char __user *, filename, | |
742 | struct compat_stat __user *, statbuf) | |
743 | { | |
744 | struct kstat stat; | |
745 | int error; | |
746 | ||
747 | error = vfs_stat(filename, &stat); | |
748 | if (error) | |
749 | return error; | |
750 | return cp_compat_stat(&stat, statbuf); | |
751 | } | |
752 | ||
753 | COMPAT_SYSCALL_DEFINE2(newlstat, const char __user *, filename, | |
754 | struct compat_stat __user *, statbuf) | |
755 | { | |
756 | struct kstat stat; | |
757 | int error; | |
758 | ||
759 | error = vfs_lstat(filename, &stat); | |
760 | if (error) | |
761 | return error; | |
762 | return cp_compat_stat(&stat, statbuf); | |
763 | } | |
764 | ||
765 | #ifndef __ARCH_WANT_STAT64 | |
766 | COMPAT_SYSCALL_DEFINE4(newfstatat, unsigned int, dfd, | |
767 | const char __user *, filename, | |
768 | struct compat_stat __user *, statbuf, int, flag) | |
769 | { | |
770 | struct kstat stat; | |
771 | int error; | |
772 | ||
773 | error = vfs_fstatat(dfd, filename, &stat, flag); | |
774 | if (error) | |
775 | return error; | |
776 | return cp_compat_stat(&stat, statbuf); | |
777 | } | |
778 | #endif | |
779 | ||
780 | COMPAT_SYSCALL_DEFINE2(newfstat, unsigned int, fd, | |
781 | struct compat_stat __user *, statbuf) | |
782 | { | |
783 | struct kstat stat; | |
784 | int error = vfs_fstat(fd, &stat); | |
785 | ||
786 | if (!error) | |
787 | error = cp_compat_stat(&stat, statbuf); | |
788 | return error; | |
789 | } | |
790 | #endif | |
791 | ||
b462707e DM |
792 | /* Caller is here responsible for sufficient locking (ie. inode->i_lock) */ |
793 | void __inode_add_bytes(struct inode *inode, loff_t bytes) | |
1da177e4 | 794 | { |
1da177e4 LT |
795 | inode->i_blocks += bytes >> 9; |
796 | bytes &= 511; | |
797 | inode->i_bytes += bytes; | |
798 | if (inode->i_bytes >= 512) { | |
799 | inode->i_blocks++; | |
800 | inode->i_bytes -= 512; | |
801 | } | |
b462707e | 802 | } |
eb315d2a | 803 | EXPORT_SYMBOL(__inode_add_bytes); |
b462707e DM |
804 | |
805 | void inode_add_bytes(struct inode *inode, loff_t bytes) | |
806 | { | |
807 | spin_lock(&inode->i_lock); | |
808 | __inode_add_bytes(inode, bytes); | |
1da177e4 LT |
809 | spin_unlock(&inode->i_lock); |
810 | } | |
811 | ||
812 | EXPORT_SYMBOL(inode_add_bytes); | |
813 | ||
1c8924eb | 814 | void __inode_sub_bytes(struct inode *inode, loff_t bytes) |
1da177e4 | 815 | { |
1da177e4 LT |
816 | inode->i_blocks -= bytes >> 9; |
817 | bytes &= 511; | |
818 | if (inode->i_bytes < bytes) { | |
819 | inode->i_blocks--; | |
820 | inode->i_bytes += 512; | |
821 | } | |
822 | inode->i_bytes -= bytes; | |
1c8924eb JK |
823 | } |
824 | ||
825 | EXPORT_SYMBOL(__inode_sub_bytes); | |
826 | ||
827 | void inode_sub_bytes(struct inode *inode, loff_t bytes) | |
828 | { | |
829 | spin_lock(&inode->i_lock); | |
830 | __inode_sub_bytes(inode, bytes); | |
1da177e4 LT |
831 | spin_unlock(&inode->i_lock); |
832 | } | |
833 | ||
834 | EXPORT_SYMBOL(inode_sub_bytes); | |
835 | ||
836 | loff_t inode_get_bytes(struct inode *inode) | |
837 | { | |
838 | loff_t ret; | |
839 | ||
840 | spin_lock(&inode->i_lock); | |
f4a8116a | 841 | ret = __inode_get_bytes(inode); |
1da177e4 LT |
842 | spin_unlock(&inode->i_lock); |
843 | return ret; | |
844 | } | |
845 | ||
846 | EXPORT_SYMBOL(inode_get_bytes); | |
847 | ||
848 | void inode_set_bytes(struct inode *inode, loff_t bytes) | |
849 | { | |
850 | /* Caller is here responsible for sufficient locking | |
851 | * (ie. inode->i_lock) */ | |
852 | inode->i_blocks = bytes >> 9; | |
853 | inode->i_bytes = bytes & 511; | |
854 | } | |
855 | ||
856 | EXPORT_SYMBOL(inode_set_bytes); |