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 | ||
630d9c47 | 8 | #include <linux/export.h> |
1da177e4 LT |
9 | #include <linux/mm.h> |
10 | #include <linux/errno.h> | |
11 | #include <linux/file.h> | |
1da177e4 LT |
12 | #include <linux/highuid.h> |
13 | #include <linux/fs.h> | |
14 | #include <linux/namei.h> | |
15 | #include <linux/security.h> | |
5b825c3a | 16 | #include <linux/cred.h> |
1da177e4 | 17 | #include <linux/syscalls.h> |
ba52de12 | 18 | #include <linux/pagemap.h> |
ac565de3 | 19 | #include <linux/compat.h> |
1da177e4 | 20 | |
7c0f6ba6 | 21 | #include <linux/uaccess.h> |
1da177e4 LT |
22 | #include <asm/unistd.h> |
23 | ||
3934e36f | 24 | #include "internal.h" |
fa2fcf4f | 25 | #include "mount.h" |
3934e36f | 26 | |
a528d35e DH |
27 | /** |
28 | * generic_fillattr - Fill in the basic attributes from the inode struct | |
0d56a451 CB |
29 | * @mnt_userns: user namespace of the mount the inode was found from |
30 | * @inode: Inode to use as the source | |
31 | * @stat: Where to fill in the attributes | |
a528d35e DH |
32 | * |
33 | * Fill in the basic attributes in the kstat structure from data that's to be | |
34 | * found on the VFS inode structure. This is the default if no getattr inode | |
35 | * operation is supplied. | |
0d56a451 CB |
36 | * |
37 | * If the inode has been found through an idmapped mount the user namespace of | |
38 | * the vfsmount must be passed through @mnt_userns. This function will then | |
39 | * take care to map the inode according to @mnt_userns before filling in the | |
40 | * uid and gid filds. On non-idmapped mounts or if permission checking is to be | |
41 | * performed on the raw inode simply passs init_user_ns. | |
a528d35e | 42 | */ |
0d56a451 CB |
43 | void generic_fillattr(struct user_namespace *mnt_userns, struct inode *inode, |
44 | struct kstat *stat) | |
1da177e4 LT |
45 | { |
46 | stat->dev = inode->i_sb->s_dev; | |
47 | stat->ino = inode->i_ino; | |
48 | stat->mode = inode->i_mode; | |
49 | stat->nlink = inode->i_nlink; | |
0d56a451 CB |
50 | stat->uid = i_uid_into_mnt(mnt_userns, inode); |
51 | stat->gid = i_gid_into_mnt(mnt_userns, inode); | |
1da177e4 | 52 | stat->rdev = inode->i_rdev; |
3ddcd056 | 53 | stat->size = i_size_read(inode); |
1da177e4 LT |
54 | stat->atime = inode->i_atime; |
55 | stat->mtime = inode->i_mtime; | |
56 | stat->ctime = inode->i_ctime; | |
93407472 | 57 | stat->blksize = i_blocksize(inode); |
3ddcd056 | 58 | stat->blocks = inode->i_blocks; |
a528d35e | 59 | } |
1da177e4 LT |
60 | EXPORT_SYMBOL(generic_fillattr); |
61 | ||
4f911138 AG |
62 | /** |
63 | * generic_fill_statx_attr - Fill in the statx attributes from the inode flags | |
64 | * @inode: Inode to use as the source | |
65 | * @stat: Where to fill in the attribute flags | |
66 | * | |
67 | * Fill in the STATX_ATTR_* flags in the kstat structure for properties of the | |
68 | * inode that are published on i_flags and enforced by the VFS. | |
69 | */ | |
70 | void generic_fill_statx_attr(struct inode *inode, struct kstat *stat) | |
71 | { | |
72 | if (inode->i_flags & S_IMMUTABLE) | |
73 | stat->attributes |= STATX_ATTR_IMMUTABLE; | |
74 | if (inode->i_flags & S_APPEND) | |
75 | stat->attributes |= STATX_ATTR_APPEND; | |
76 | stat->attributes_mask |= KSTAT_ATTR_VFS_FLAGS; | |
77 | } | |
78 | EXPORT_SYMBOL(generic_fill_statx_attr); | |
79 | ||
b7a6ec52 BF |
80 | /** |
81 | * vfs_getattr_nosec - getattr without security checks | |
82 | * @path: file to get attributes from | |
83 | * @stat: structure to return attributes in | |
a528d35e | 84 | * @request_mask: STATX_xxx flags indicating what the caller wants |
f2d077ff | 85 | * @query_flags: Query mode (AT_STATX_SYNC_TYPE) |
b7a6ec52 BF |
86 | * |
87 | * Get attributes without calling security_inode_getattr. | |
88 | * | |
89 | * Currently the only caller other than vfs_getattr is internal to the | |
a528d35e DH |
90 | * filehandle lookup code, which uses only the inode number and returns no |
91 | * attributes to any user. Any other code probably wants vfs_getattr. | |
b7a6ec52 | 92 | */ |
a528d35e DH |
93 | int vfs_getattr_nosec(const struct path *path, struct kstat *stat, |
94 | u32 request_mask, unsigned int query_flags) | |
1da177e4 | 95 | { |
549c7297 | 96 | struct user_namespace *mnt_userns; |
bb668734 | 97 | struct inode *inode = d_backing_inode(path->dentry); |
1da177e4 | 98 | |
a528d35e DH |
99 | memset(stat, 0, sizeof(*stat)); |
100 | stat->result_mask |= STATX_BASIC_STATS; | |
f2d077ff | 101 | query_flags &= AT_STATX_SYNC_TYPE; |
801e5237 CH |
102 | |
103 | /* allow the fs to override these if it really wants to */ | |
761e28fa MS |
104 | /* SB_NOATIME means filesystem supplies dummy atime value */ |
105 | if (inode->i_sb->s_flags & SB_NOATIME) | |
801e5237 | 106 | stat->result_mask &= ~STATX_ATIME; |
5afa7e8b TT |
107 | |
108 | /* | |
109 | * Note: If you add another clause to set an attribute flag, please | |
110 | * update attributes_mask below. | |
111 | */ | |
801e5237 CH |
112 | if (IS_AUTOMOUNT(inode)) |
113 | stat->attributes |= STATX_ATTR_AUTOMOUNT; | |
114 | ||
712b2698 IW |
115 | if (IS_DAX(inode)) |
116 | stat->attributes |= STATX_ATTR_DAX; | |
117 | ||
5afa7e8b TT |
118 | stat->attributes_mask |= (STATX_ATTR_AUTOMOUNT | |
119 | STATX_ATTR_DAX); | |
120 | ||
549c7297 | 121 | mnt_userns = mnt_user_ns(path->mnt); |
1da177e4 | 122 | if (inode->i_op->getattr) |
549c7297 CB |
123 | return inode->i_op->getattr(mnt_userns, path, stat, |
124 | request_mask, query_flags); | |
1da177e4 | 125 | |
549c7297 | 126 | generic_fillattr(mnt_userns, inode, stat); |
1da177e4 LT |
127 | return 0; |
128 | } | |
b7a6ec52 BF |
129 | EXPORT_SYMBOL(vfs_getattr_nosec); |
130 | ||
a528d35e DH |
131 | /* |
132 | * vfs_getattr - Get the enhanced basic attributes of a file | |
133 | * @path: The file of interest | |
134 | * @stat: Where to return the statistics | |
135 | * @request_mask: STATX_xxx flags indicating what the caller wants | |
f2d077ff | 136 | * @query_flags: Query mode (AT_STATX_SYNC_TYPE) |
a528d35e DH |
137 | * |
138 | * Ask the filesystem for a file's attributes. The caller must indicate in | |
139 | * request_mask and query_flags to indicate what they want. | |
140 | * | |
141 | * If the file is remote, the filesystem can be forced to update the attributes | |
142 | * from the backing store by passing AT_STATX_FORCE_SYNC in query_flags or can | |
143 | * suppress the update by passing AT_STATX_DONT_SYNC. | |
144 | * | |
145 | * Bits must have been set in request_mask to indicate which attributes the | |
146 | * caller wants retrieving. Any such attribute not requested may be returned | |
147 | * anyway, but the value may be approximate, and, if remote, may not have been | |
148 | * synchronised with the server. | |
149 | * | |
150 | * 0 will be returned on success, and a -ve error code if unsuccessful. | |
151 | */ | |
152 | int vfs_getattr(const struct path *path, struct kstat *stat, | |
153 | u32 request_mask, unsigned int query_flags) | |
b7a6ec52 BF |
154 | { |
155 | int retval; | |
156 | ||
3f7036a0 | 157 | retval = security_inode_getattr(path); |
b7a6ec52 BF |
158 | if (retval) |
159 | return retval; | |
a528d35e | 160 | return vfs_getattr_nosec(path, stat, request_mask, query_flags); |
b7a6ec52 | 161 | } |
1da177e4 LT |
162 | EXPORT_SYMBOL(vfs_getattr); |
163 | ||
a528d35e | 164 | /** |
da9aa5d9 | 165 | * vfs_fstat - Get the basic attributes by file descriptor |
a528d35e DH |
166 | * @fd: The file descriptor referring to the file of interest |
167 | * @stat: The result structure to fill in. | |
a528d35e DH |
168 | * |
169 | * This function is a wrapper around vfs_getattr(). The main difference is | |
170 | * that it uses a file descriptor to determine the file location. | |
171 | * | |
172 | * 0 will be returned on success, and a -ve error code if unsuccessful. | |
173 | */ | |
da9aa5d9 | 174 | int vfs_fstat(int fd, struct kstat *stat) |
1da177e4 | 175 | { |
8c7493aa | 176 | struct fd f; |
da9aa5d9 | 177 | int error; |
8c7493aa EB |
178 | |
179 | f = fdget_raw(fd); | |
da9aa5d9 CH |
180 | if (!f.file) |
181 | return -EBADF; | |
182 | error = vfs_getattr(&f.file->f_path, stat, STATX_BASIC_STATS, 0); | |
183 | fdput(f); | |
1da177e4 LT |
184 | return error; |
185 | } | |
1da177e4 | 186 | |
1b6fe6e0 SR |
187 | int getname_statx_lookup_flags(int flags) |
188 | { | |
189 | int lookup_flags = 0; | |
190 | ||
191 | if (!(flags & AT_SYMLINK_NOFOLLOW)) | |
192 | lookup_flags |= LOOKUP_FOLLOW; | |
193 | if (!(flags & AT_NO_AUTOMOUNT)) | |
194 | lookup_flags |= LOOKUP_AUTOMOUNT; | |
195 | if (flags & AT_EMPTY_PATH) | |
196 | lookup_flags |= LOOKUP_EMPTY; | |
197 | ||
198 | return lookup_flags; | |
199 | } | |
200 | ||
a528d35e DH |
201 | /** |
202 | * vfs_statx - Get basic and extra attributes by filename | |
203 | * @dfd: A file descriptor representing the base dir for a relative filename | |
204 | * @filename: The name of the file of interest | |
205 | * @flags: Flags to control the query | |
206 | * @stat: The result structure to fill in. | |
207 | * @request_mask: STATX_xxx flags indicating what the caller wants | |
208 | * | |
209 | * This function is a wrapper around vfs_getattr(). The main difference is | |
210 | * that it uses a filename and base directory to determine the file location. | |
211 | * Additionally, the use of AT_SYMLINK_NOFOLLOW in flags will prevent a symlink | |
212 | * at the given name from being referenced. | |
213 | * | |
a528d35e DH |
214 | * 0 will be returned on success, and a -ve error code if unsuccessful. |
215 | */ | |
1b6fe6e0 | 216 | static int vfs_statx(int dfd, struct filename *filename, int flags, |
a528d35e | 217 | struct kstat *stat, u32 request_mask) |
0112fc22 | 218 | { |
2eae7a18 | 219 | struct path path; |
1b6fe6e0 | 220 | unsigned int lookup_flags = getname_statx_lookup_flags(flags); |
b3f05150 | 221 | int error; |
0112fc22 | 222 | |
b3f05150 | 223 | if (flags & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT | AT_EMPTY_PATH | |
f2d077ff | 224 | AT_STATX_SYNC_TYPE)) |
a528d35e | 225 | return -EINVAL; |
b3f05150 | 226 | |
836fb7e7 | 227 | retry: |
1b6fe6e0 | 228 | error = filename_lookup(dfd, filename, lookup_flags, &path, NULL); |
2eae7a18 CH |
229 | if (error) |
230 | goto out; | |
231 | ||
a528d35e | 232 | error = vfs_getattr(&path, stat, request_mask, flags); |
fa2fcf4f MS |
233 | stat->mnt_id = real_mount(path.mnt)->mnt_id; |
234 | stat->result_mask |= STATX_MNT_ID; | |
80340fe3 MS |
235 | if (path.mnt->mnt_root == path.dentry) |
236 | stat->attributes |= STATX_ATTR_MOUNT_ROOT; | |
237 | stat->attributes_mask |= STATX_ATTR_MOUNT_ROOT; | |
2eae7a18 | 238 | path_put(&path); |
836fb7e7 JL |
239 | if (retry_estale(error, lookup_flags)) { |
240 | lookup_flags |= LOOKUP_REVAL; | |
241 | goto retry; | |
242 | } | |
0112fc22 OD |
243 | out: |
244 | return error; | |
245 | } | |
2eae7a18 | 246 | |
09f1bde4 CH |
247 | int vfs_fstatat(int dfd, const char __user *filename, |
248 | struct kstat *stat, int flags) | |
249 | { | |
1b6fe6e0 SR |
250 | int ret; |
251 | int statx_flags = flags | AT_NO_AUTOMOUNT; | |
252 | struct filename *name; | |
253 | ||
254 | name = getname_flags(filename, getname_statx_lookup_flags(statx_flags), NULL); | |
255 | ret = vfs_statx(dfd, name, statx_flags, stat, STATX_BASIC_STATS); | |
256 | putname(name); | |
257 | ||
258 | return ret; | |
09f1bde4 | 259 | } |
0112fc22 | 260 | |
1da177e4 LT |
261 | #ifdef __ARCH_WANT_OLD_STAT |
262 | ||
263 | /* | |
264 | * For backward compatibility? Maybe this should be moved | |
265 | * into arch/i386 instead? | |
266 | */ | |
267 | static int cp_old_stat(struct kstat *stat, struct __old_kernel_stat __user * statbuf) | |
268 | { | |
269 | static int warncount = 5; | |
270 | struct __old_kernel_stat tmp; | |
a528d35e | 271 | |
1da177e4 LT |
272 | if (warncount > 0) { |
273 | warncount--; | |
274 | printk(KERN_WARNING "VFS: Warning: %s using old stat() call. Recompile your binary.\n", | |
275 | current->comm); | |
276 | } else if (warncount < 0) { | |
277 | /* it's laughable, but... */ | |
278 | warncount = 0; | |
279 | } | |
280 | ||
281 | memset(&tmp, 0, sizeof(struct __old_kernel_stat)); | |
282 | tmp.st_dev = old_encode_dev(stat->dev); | |
283 | tmp.st_ino = stat->ino; | |
afefdbb2 DH |
284 | if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino) |
285 | return -EOVERFLOW; | |
1da177e4 LT |
286 | tmp.st_mode = stat->mode; |
287 | tmp.st_nlink = stat->nlink; | |
288 | if (tmp.st_nlink != stat->nlink) | |
289 | return -EOVERFLOW; | |
a7c1938e EB |
290 | SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid)); |
291 | SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid)); | |
1da177e4 LT |
292 | tmp.st_rdev = old_encode_dev(stat->rdev); |
293 | #if BITS_PER_LONG == 32 | |
294 | if (stat->size > MAX_NON_LFS) | |
295 | return -EOVERFLOW; | |
a528d35e | 296 | #endif |
1da177e4 LT |
297 | tmp.st_size = stat->size; |
298 | tmp.st_atime = stat->atime.tv_sec; | |
299 | tmp.st_mtime = stat->mtime.tv_sec; | |
300 | tmp.st_ctime = stat->ctime.tv_sec; | |
301 | return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0; | |
302 | } | |
303 | ||
c7887325 DH |
304 | SYSCALL_DEFINE2(stat, const char __user *, filename, |
305 | struct __old_kernel_stat __user *, statbuf) | |
1da177e4 LT |
306 | { |
307 | struct kstat stat; | |
2eae7a18 | 308 | int error; |
1da177e4 | 309 | |
2eae7a18 CH |
310 | error = vfs_stat(filename, &stat); |
311 | if (error) | |
312 | return error; | |
1da177e4 | 313 | |
2eae7a18 | 314 | return cp_old_stat(&stat, statbuf); |
1da177e4 | 315 | } |
257ac264 | 316 | |
c7887325 DH |
317 | SYSCALL_DEFINE2(lstat, const char __user *, filename, |
318 | struct __old_kernel_stat __user *, statbuf) | |
1da177e4 LT |
319 | { |
320 | struct kstat stat; | |
2eae7a18 | 321 | int error; |
1da177e4 | 322 | |
2eae7a18 CH |
323 | error = vfs_lstat(filename, &stat); |
324 | if (error) | |
325 | return error; | |
1da177e4 | 326 | |
2eae7a18 | 327 | return cp_old_stat(&stat, statbuf); |
1da177e4 | 328 | } |
257ac264 HC |
329 | |
330 | SYSCALL_DEFINE2(fstat, unsigned int, fd, struct __old_kernel_stat __user *, statbuf) | |
1da177e4 LT |
331 | { |
332 | struct kstat stat; | |
333 | int error = vfs_fstat(fd, &stat); | |
334 | ||
335 | if (!error) | |
336 | error = cp_old_stat(&stat, statbuf); | |
337 | ||
338 | return error; | |
339 | } | |
340 | ||
341 | #endif /* __ARCH_WANT_OLD_STAT */ | |
342 | ||
82b355d1 AB |
343 | #ifdef __ARCH_WANT_NEW_STAT |
344 | ||
a52dd971 LT |
345 | #if BITS_PER_LONG == 32 |
346 | # define choose_32_64(a,b) a | |
347 | #else | |
348 | # define choose_32_64(a,b) b | |
349 | #endif | |
350 | ||
8529f613 LT |
351 | #ifndef INIT_STRUCT_STAT_PADDING |
352 | # define INIT_STRUCT_STAT_PADDING(st) memset(&st, 0, sizeof(st)) | |
353 | #endif | |
354 | ||
1da177e4 LT |
355 | static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf) |
356 | { | |
357 | struct stat tmp; | |
358 | ||
932aba1e MP |
359 | if (sizeof(tmp.st_dev) < 4 && !old_valid_dev(stat->dev)) |
360 | return -EOVERFLOW; | |
361 | if (sizeof(tmp.st_rdev) < 4 && !old_valid_dev(stat->rdev)) | |
1da177e4 | 362 | return -EOVERFLOW; |
a52dd971 LT |
363 | #if BITS_PER_LONG == 32 |
364 | if (stat->size > MAX_NON_LFS) | |
1da177e4 LT |
365 | return -EOVERFLOW; |
366 | #endif | |
367 | ||
8529f613 | 368 | INIT_STRUCT_STAT_PADDING(tmp); |
932aba1e | 369 | tmp.st_dev = new_encode_dev(stat->dev); |
1da177e4 | 370 | tmp.st_ino = stat->ino; |
afefdbb2 DH |
371 | if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino) |
372 | return -EOVERFLOW; | |
1da177e4 LT |
373 | tmp.st_mode = stat->mode; |
374 | tmp.st_nlink = stat->nlink; | |
375 | if (tmp.st_nlink != stat->nlink) | |
376 | return -EOVERFLOW; | |
a7c1938e EB |
377 | SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid)); |
378 | SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid)); | |
932aba1e | 379 | tmp.st_rdev = new_encode_dev(stat->rdev); |
1da177e4 LT |
380 | tmp.st_size = stat->size; |
381 | tmp.st_atime = stat->atime.tv_sec; | |
382 | tmp.st_mtime = stat->mtime.tv_sec; | |
383 | tmp.st_ctime = stat->ctime.tv_sec; | |
384 | #ifdef STAT_HAVE_NSEC | |
385 | tmp.st_atime_nsec = stat->atime.tv_nsec; | |
386 | tmp.st_mtime_nsec = stat->mtime.tv_nsec; | |
387 | tmp.st_ctime_nsec = stat->ctime.tv_nsec; | |
388 | #endif | |
389 | tmp.st_blocks = stat->blocks; | |
390 | tmp.st_blksize = stat->blksize; | |
391 | return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0; | |
392 | } | |
393 | ||
c7887325 DH |
394 | SYSCALL_DEFINE2(newstat, const char __user *, filename, |
395 | struct stat __user *, statbuf) | |
5590ff0d UD |
396 | { |
397 | struct kstat stat; | |
2eae7a18 | 398 | int error = vfs_stat(filename, &stat); |
5590ff0d | 399 | |
2eae7a18 CH |
400 | if (error) |
401 | return error; | |
402 | return cp_new_stat(&stat, statbuf); | |
5590ff0d UD |
403 | } |
404 | ||
c7887325 DH |
405 | SYSCALL_DEFINE2(newlstat, const char __user *, filename, |
406 | struct stat __user *, statbuf) | |
1da177e4 LT |
407 | { |
408 | struct kstat stat; | |
2eae7a18 | 409 | int error; |
1da177e4 | 410 | |
2eae7a18 CH |
411 | error = vfs_lstat(filename, &stat); |
412 | if (error) | |
413 | return error; | |
1da177e4 | 414 | |
2eae7a18 | 415 | return cp_new_stat(&stat, statbuf); |
1da177e4 | 416 | } |
5590ff0d | 417 | |
2833c28a | 418 | #if !defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_SYS_NEWFSTATAT) |
c7887325 | 419 | SYSCALL_DEFINE4(newfstatat, int, dfd, const char __user *, filename, |
6559eed8 | 420 | struct stat __user *, statbuf, int, flag) |
1da177e4 LT |
421 | { |
422 | struct kstat stat; | |
0112fc22 | 423 | int error; |
1da177e4 | 424 | |
0112fc22 OD |
425 | error = vfs_fstatat(dfd, filename, &stat, flag); |
426 | if (error) | |
427 | return error; | |
428 | return cp_new_stat(&stat, statbuf); | |
1da177e4 | 429 | } |
cff2b760 | 430 | #endif |
5590ff0d | 431 | |
257ac264 | 432 | SYSCALL_DEFINE2(newfstat, unsigned int, fd, struct stat __user *, statbuf) |
1da177e4 LT |
433 | { |
434 | struct kstat stat; | |
435 | int error = vfs_fstat(fd, &stat); | |
436 | ||
437 | if (!error) | |
438 | error = cp_new_stat(&stat, statbuf); | |
439 | ||
440 | return error; | |
441 | } | |
82b355d1 | 442 | #endif |
1da177e4 | 443 | |
2dae0248 DB |
444 | static int do_readlinkat(int dfd, const char __user *pathname, |
445 | char __user *buf, int bufsiz) | |
1da177e4 | 446 | { |
2d8f3038 | 447 | struct path path; |
1da177e4 | 448 | int error; |
1fa1e7f6 | 449 | int empty = 0; |
7955119e | 450 | unsigned int lookup_flags = LOOKUP_EMPTY; |
1da177e4 LT |
451 | |
452 | if (bufsiz <= 0) | |
453 | return -EINVAL; | |
454 | ||
7955119e JL |
455 | retry: |
456 | error = user_path_at_empty(dfd, pathname, lookup_flags, &path, &empty); | |
1da177e4 | 457 | if (!error) { |
bb668734 | 458 | struct inode *inode = d_backing_inode(path.dentry); |
1da177e4 | 459 | |
1fa1e7f6 | 460 | error = empty ? -ENOENT : -EINVAL; |
fd4a0edf MS |
461 | /* |
462 | * AFS mountpoints allow readlink(2) but are not symlinks | |
463 | */ | |
464 | if (d_is_symlink(path.dentry) || inode->i_op->readlink) { | |
2d8f3038 | 465 | error = security_inode_readlink(path.dentry); |
1da177e4 | 466 | if (!error) { |
68ac1234 | 467 | touch_atime(&path); |
fd4a0edf | 468 | error = vfs_readlink(path.dentry, buf, bufsiz); |
1da177e4 LT |
469 | } |
470 | } | |
2d8f3038 | 471 | path_put(&path); |
7955119e JL |
472 | if (retry_estale(error, lookup_flags)) { |
473 | lookup_flags |= LOOKUP_REVAL; | |
474 | goto retry; | |
475 | } | |
1da177e4 LT |
476 | } |
477 | return error; | |
478 | } | |
479 | ||
2dae0248 DB |
480 | SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname, |
481 | char __user *, buf, int, bufsiz) | |
482 | { | |
483 | return do_readlinkat(dfd, pathname, buf, bufsiz); | |
484 | } | |
485 | ||
002c8976 HC |
486 | SYSCALL_DEFINE3(readlink, const char __user *, path, char __user *, buf, |
487 | int, bufsiz) | |
5590ff0d | 488 | { |
2dae0248 | 489 | return do_readlinkat(AT_FDCWD, path, buf, bufsiz); |
5590ff0d UD |
490 | } |
491 | ||
1da177e4 LT |
492 | |
493 | /* ---------- LFS-64 ----------- */ | |
0753f70f | 494 | #if defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_COMPAT_STAT64) |
1da177e4 | 495 | |
8529f613 LT |
496 | #ifndef INIT_STRUCT_STAT64_PADDING |
497 | # define INIT_STRUCT_STAT64_PADDING(st) memset(&st, 0, sizeof(st)) | |
498 | #endif | |
499 | ||
1da177e4 LT |
500 | static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf) |
501 | { | |
502 | struct stat64 tmp; | |
503 | ||
8529f613 | 504 | INIT_STRUCT_STAT64_PADDING(tmp); |
1da177e4 LT |
505 | #ifdef CONFIG_MIPS |
506 | /* mips has weird padding, so we don't get 64 bits there */ | |
1da177e4 LT |
507 | tmp.st_dev = new_encode_dev(stat->dev); |
508 | tmp.st_rdev = new_encode_dev(stat->rdev); | |
509 | #else | |
510 | tmp.st_dev = huge_encode_dev(stat->dev); | |
511 | tmp.st_rdev = huge_encode_dev(stat->rdev); | |
512 | #endif | |
513 | tmp.st_ino = stat->ino; | |
afefdbb2 DH |
514 | if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino) |
515 | return -EOVERFLOW; | |
1da177e4 LT |
516 | #ifdef STAT64_HAS_BROKEN_ST_INO |
517 | tmp.__st_ino = stat->ino; | |
518 | #endif | |
519 | tmp.st_mode = stat->mode; | |
520 | tmp.st_nlink = stat->nlink; | |
a7c1938e EB |
521 | tmp.st_uid = from_kuid_munged(current_user_ns(), stat->uid); |
522 | tmp.st_gid = from_kgid_munged(current_user_ns(), stat->gid); | |
1da177e4 LT |
523 | tmp.st_atime = stat->atime.tv_sec; |
524 | tmp.st_atime_nsec = stat->atime.tv_nsec; | |
525 | tmp.st_mtime = stat->mtime.tv_sec; | |
526 | tmp.st_mtime_nsec = stat->mtime.tv_nsec; | |
527 | tmp.st_ctime = stat->ctime.tv_sec; | |
528 | tmp.st_ctime_nsec = stat->ctime.tv_nsec; | |
529 | tmp.st_size = stat->size; | |
530 | tmp.st_blocks = stat->blocks; | |
531 | tmp.st_blksize = stat->blksize; | |
532 | return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0; | |
533 | } | |
534 | ||
c7887325 DH |
535 | SYSCALL_DEFINE2(stat64, const char __user *, filename, |
536 | struct stat64 __user *, statbuf) | |
1da177e4 LT |
537 | { |
538 | struct kstat stat; | |
539 | int error = vfs_stat(filename, &stat); | |
540 | ||
541 | if (!error) | |
542 | error = cp_new_stat64(&stat, statbuf); | |
543 | ||
544 | return error; | |
545 | } | |
257ac264 | 546 | |
c7887325 DH |
547 | SYSCALL_DEFINE2(lstat64, const char __user *, filename, |
548 | struct stat64 __user *, statbuf) | |
1da177e4 LT |
549 | { |
550 | struct kstat stat; | |
551 | int error = vfs_lstat(filename, &stat); | |
552 | ||
553 | if (!error) | |
554 | error = cp_new_stat64(&stat, statbuf); | |
555 | ||
556 | return error; | |
557 | } | |
257ac264 HC |
558 | |
559 | SYSCALL_DEFINE2(fstat64, unsigned long, fd, struct stat64 __user *, statbuf) | |
1da177e4 LT |
560 | { |
561 | struct kstat stat; | |
562 | int error = vfs_fstat(fd, &stat); | |
563 | ||
564 | if (!error) | |
565 | error = cp_new_stat64(&stat, statbuf); | |
566 | ||
567 | return error; | |
568 | } | |
569 | ||
c7887325 | 570 | SYSCALL_DEFINE4(fstatat64, int, dfd, const char __user *, filename, |
6559eed8 | 571 | struct stat64 __user *, statbuf, int, flag) |
cff2b760 UD |
572 | { |
573 | struct kstat stat; | |
0112fc22 | 574 | int error; |
cff2b760 | 575 | |
0112fc22 OD |
576 | error = vfs_fstatat(dfd, filename, &stat, flag); |
577 | if (error) | |
578 | return error; | |
579 | return cp_new_stat64(&stat, statbuf); | |
cff2b760 | 580 | } |
0753f70f | 581 | #endif /* __ARCH_WANT_STAT64 || __ARCH_WANT_COMPAT_STAT64 */ |
1da177e4 | 582 | |
6f88cc17 | 583 | static noinline_for_stack int |
64bd7204 | 584 | cp_statx(const struct kstat *stat, struct statx __user *buffer) |
a528d35e | 585 | { |
64bd7204 EB |
586 | struct statx tmp; |
587 | ||
588 | memset(&tmp, 0, sizeof(tmp)); | |
589 | ||
590 | tmp.stx_mask = stat->result_mask; | |
591 | tmp.stx_blksize = stat->blksize; | |
592 | tmp.stx_attributes = stat->attributes; | |
593 | tmp.stx_nlink = stat->nlink; | |
594 | tmp.stx_uid = from_kuid_munged(current_user_ns(), stat->uid); | |
595 | tmp.stx_gid = from_kgid_munged(current_user_ns(), stat->gid); | |
596 | tmp.stx_mode = stat->mode; | |
597 | tmp.stx_ino = stat->ino; | |
598 | tmp.stx_size = stat->size; | |
599 | tmp.stx_blocks = stat->blocks; | |
3209f68b | 600 | tmp.stx_attributes_mask = stat->attributes_mask; |
64bd7204 EB |
601 | tmp.stx_atime.tv_sec = stat->atime.tv_sec; |
602 | tmp.stx_atime.tv_nsec = stat->atime.tv_nsec; | |
603 | tmp.stx_btime.tv_sec = stat->btime.tv_sec; | |
604 | tmp.stx_btime.tv_nsec = stat->btime.tv_nsec; | |
605 | tmp.stx_ctime.tv_sec = stat->ctime.tv_sec; | |
606 | tmp.stx_ctime.tv_nsec = stat->ctime.tv_nsec; | |
607 | tmp.stx_mtime.tv_sec = stat->mtime.tv_sec; | |
608 | tmp.stx_mtime.tv_nsec = stat->mtime.tv_nsec; | |
609 | tmp.stx_rdev_major = MAJOR(stat->rdev); | |
610 | tmp.stx_rdev_minor = MINOR(stat->rdev); | |
611 | tmp.stx_dev_major = MAJOR(stat->dev); | |
612 | tmp.stx_dev_minor = MINOR(stat->dev); | |
fa2fcf4f | 613 | tmp.stx_mnt_id = stat->mnt_id; |
64bd7204 EB |
614 | |
615 | return copy_to_user(buffer, &tmp, sizeof(tmp)) ? -EFAULT : 0; | |
a528d35e DH |
616 | } |
617 | ||
1b6fe6e0 | 618 | int do_statx(int dfd, struct filename *filename, unsigned int flags, |
0018784f BM |
619 | unsigned int mask, struct statx __user *buffer) |
620 | { | |
621 | struct kstat stat; | |
622 | int error; | |
623 | ||
624 | if (mask & STATX__RESERVED) | |
625 | return -EINVAL; | |
626 | if ((flags & AT_STATX_SYNC_TYPE) == AT_STATX_SYNC_TYPE) | |
627 | return -EINVAL; | |
628 | ||
629 | error = vfs_statx(dfd, filename, flags, &stat, mask); | |
630 | if (error) | |
631 | return error; | |
632 | ||
633 | return cp_statx(&stat, buffer); | |
634 | } | |
635 | ||
a528d35e DH |
636 | /** |
637 | * sys_statx - System call to get enhanced stats | |
638 | * @dfd: Base directory to pathwalk from *or* fd to stat. | |
1e2f82d1 | 639 | * @filename: File to stat or "" with AT_EMPTY_PATH |
a528d35e DH |
640 | * @flags: AT_* flags to control pathwalk. |
641 | * @mask: Parts of statx struct actually required. | |
642 | * @buffer: Result buffer. | |
643 | * | |
1e2f82d1 DH |
644 | * Note that fstat() can be emulated by setting dfd to the fd of interest, |
645 | * supplying "" as the filename and setting AT_EMPTY_PATH in the flags. | |
a528d35e DH |
646 | */ |
647 | SYSCALL_DEFINE5(statx, | |
648 | int, dfd, const char __user *, filename, unsigned, flags, | |
649 | unsigned int, mask, | |
650 | struct statx __user *, buffer) | |
651 | { | |
1b6fe6e0 SR |
652 | int ret; |
653 | struct filename *name; | |
654 | ||
655 | name = getname_flags(filename, getname_statx_lookup_flags(flags), NULL); | |
656 | ret = do_statx(dfd, name, flags, mask, buffer); | |
657 | putname(name); | |
658 | ||
659 | return ret; | |
a528d35e DH |
660 | } |
661 | ||
f18ed30d | 662 | #if defined(CONFIG_COMPAT) && defined(__ARCH_WANT_COMPAT_STAT) |
ac565de3 AV |
663 | static int cp_compat_stat(struct kstat *stat, struct compat_stat __user *ubuf) |
664 | { | |
665 | struct compat_stat tmp; | |
666 | ||
932aba1e MP |
667 | if (sizeof(tmp.st_dev) < 4 && !old_valid_dev(stat->dev)) |
668 | return -EOVERFLOW; | |
669 | if (sizeof(tmp.st_rdev) < 4 && !old_valid_dev(stat->rdev)) | |
ac565de3 AV |
670 | return -EOVERFLOW; |
671 | ||
672 | memset(&tmp, 0, sizeof(tmp)); | |
932aba1e | 673 | tmp.st_dev = new_encode_dev(stat->dev); |
ac565de3 AV |
674 | tmp.st_ino = stat->ino; |
675 | if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino) | |
676 | return -EOVERFLOW; | |
677 | tmp.st_mode = stat->mode; | |
678 | tmp.st_nlink = stat->nlink; | |
679 | if (tmp.st_nlink != stat->nlink) | |
680 | return -EOVERFLOW; | |
681 | SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid)); | |
682 | SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid)); | |
932aba1e | 683 | tmp.st_rdev = new_encode_dev(stat->rdev); |
ac565de3 AV |
684 | if ((u64) stat->size > MAX_NON_LFS) |
685 | return -EOVERFLOW; | |
686 | tmp.st_size = stat->size; | |
687 | tmp.st_atime = stat->atime.tv_sec; | |
688 | tmp.st_atime_nsec = stat->atime.tv_nsec; | |
689 | tmp.st_mtime = stat->mtime.tv_sec; | |
690 | tmp.st_mtime_nsec = stat->mtime.tv_nsec; | |
691 | tmp.st_ctime = stat->ctime.tv_sec; | |
692 | tmp.st_ctime_nsec = stat->ctime.tv_nsec; | |
693 | tmp.st_blocks = stat->blocks; | |
694 | tmp.st_blksize = stat->blksize; | |
695 | return copy_to_user(ubuf, &tmp, sizeof(tmp)) ? -EFAULT : 0; | |
696 | } | |
697 | ||
698 | COMPAT_SYSCALL_DEFINE2(newstat, const char __user *, filename, | |
699 | struct compat_stat __user *, statbuf) | |
700 | { | |
701 | struct kstat stat; | |
702 | int error; | |
703 | ||
704 | error = vfs_stat(filename, &stat); | |
705 | if (error) | |
706 | return error; | |
707 | return cp_compat_stat(&stat, statbuf); | |
708 | } | |
709 | ||
710 | COMPAT_SYSCALL_DEFINE2(newlstat, const char __user *, filename, | |
711 | struct compat_stat __user *, statbuf) | |
712 | { | |
713 | struct kstat stat; | |
714 | int error; | |
715 | ||
716 | error = vfs_lstat(filename, &stat); | |
717 | if (error) | |
718 | return error; | |
719 | return cp_compat_stat(&stat, statbuf); | |
720 | } | |
721 | ||
722 | #ifndef __ARCH_WANT_STAT64 | |
723 | COMPAT_SYSCALL_DEFINE4(newfstatat, unsigned int, dfd, | |
724 | const char __user *, filename, | |
725 | struct compat_stat __user *, statbuf, int, flag) | |
726 | { | |
727 | struct kstat stat; | |
728 | int error; | |
729 | ||
730 | error = vfs_fstatat(dfd, filename, &stat, flag); | |
731 | if (error) | |
732 | return error; | |
733 | return cp_compat_stat(&stat, statbuf); | |
734 | } | |
735 | #endif | |
736 | ||
737 | COMPAT_SYSCALL_DEFINE2(newfstat, unsigned int, fd, | |
738 | struct compat_stat __user *, statbuf) | |
739 | { | |
740 | struct kstat stat; | |
741 | int error = vfs_fstat(fd, &stat); | |
742 | ||
743 | if (!error) | |
744 | error = cp_compat_stat(&stat, statbuf); | |
745 | return error; | |
746 | } | |
747 | #endif | |
748 | ||
b462707e DM |
749 | /* Caller is here responsible for sufficient locking (ie. inode->i_lock) */ |
750 | void __inode_add_bytes(struct inode *inode, loff_t bytes) | |
1da177e4 | 751 | { |
1da177e4 LT |
752 | inode->i_blocks += bytes >> 9; |
753 | bytes &= 511; | |
754 | inode->i_bytes += bytes; | |
755 | if (inode->i_bytes >= 512) { | |
756 | inode->i_blocks++; | |
757 | inode->i_bytes -= 512; | |
758 | } | |
b462707e | 759 | } |
eb315d2a | 760 | EXPORT_SYMBOL(__inode_add_bytes); |
b462707e DM |
761 | |
762 | void inode_add_bytes(struct inode *inode, loff_t bytes) | |
763 | { | |
764 | spin_lock(&inode->i_lock); | |
765 | __inode_add_bytes(inode, bytes); | |
1da177e4 LT |
766 | spin_unlock(&inode->i_lock); |
767 | } | |
768 | ||
769 | EXPORT_SYMBOL(inode_add_bytes); | |
770 | ||
1c8924eb | 771 | void __inode_sub_bytes(struct inode *inode, loff_t bytes) |
1da177e4 | 772 | { |
1da177e4 LT |
773 | inode->i_blocks -= bytes >> 9; |
774 | bytes &= 511; | |
775 | if (inode->i_bytes < bytes) { | |
776 | inode->i_blocks--; | |
777 | inode->i_bytes += 512; | |
778 | } | |
779 | inode->i_bytes -= bytes; | |
1c8924eb JK |
780 | } |
781 | ||
782 | EXPORT_SYMBOL(__inode_sub_bytes); | |
783 | ||
784 | void inode_sub_bytes(struct inode *inode, loff_t bytes) | |
785 | { | |
786 | spin_lock(&inode->i_lock); | |
787 | __inode_sub_bytes(inode, bytes); | |
1da177e4 LT |
788 | spin_unlock(&inode->i_lock); |
789 | } | |
790 | ||
791 | EXPORT_SYMBOL(inode_sub_bytes); | |
792 | ||
793 | loff_t inode_get_bytes(struct inode *inode) | |
794 | { | |
795 | loff_t ret; | |
796 | ||
797 | spin_lock(&inode->i_lock); | |
f4a8116a | 798 | ret = __inode_get_bytes(inode); |
1da177e4 LT |
799 | spin_unlock(&inode->i_lock); |
800 | return ret; | |
801 | } | |
802 | ||
803 | EXPORT_SYMBOL(inode_get_bytes); | |
804 | ||
805 | void inode_set_bytes(struct inode *inode, loff_t bytes) | |
806 | { | |
807 | /* Caller is here responsible for sufficient locking | |
808 | * (ie. inode->i_lock) */ | |
809 | inode->i_blocks = bytes >> 9; | |
810 | inode->i_bytes = bytes & 511; | |
811 | } | |
812 | ||
813 | EXPORT_SYMBOL(inode_set_bytes); |