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> |
1da177e4 | 21 | |
7c0f6ba6 | 22 | #include <linux/uaccess.h> |
1da177e4 LT |
23 | #include <asm/unistd.h> |
24 | ||
3934e36f | 25 | #include "internal.h" |
fa2fcf4f | 26 | #include "mount.h" |
3934e36f | 27 | |
a528d35e DH |
28 | /** |
29 | * generic_fillattr - Fill in the basic attributes from the inode struct | |
0d56a451 CB |
30 | * @mnt_userns: user namespace of the mount the inode was found from |
31 | * @inode: Inode to use as the source | |
32 | * @stat: Where to fill in the attributes | |
a528d35e DH |
33 | * |
34 | * Fill in the basic attributes in the kstat structure from data that's to be | |
35 | * found on the VFS inode structure. This is the default if no getattr inode | |
36 | * operation is supplied. | |
0d56a451 CB |
37 | * |
38 | * If the inode has been found through an idmapped mount the user namespace of | |
39 | * the vfsmount must be passed through @mnt_userns. This function will then | |
40 | * take care to map the inode according to @mnt_userns before filling in the | |
41 | * uid and gid filds. On non-idmapped mounts or if permission checking is to be | |
42 | * performed on the raw inode simply passs init_user_ns. | |
a528d35e | 43 | */ |
0d56a451 CB |
44 | void generic_fillattr(struct user_namespace *mnt_userns, struct inode *inode, |
45 | struct kstat *stat) | |
1da177e4 | 46 | { |
a2bd096f CB |
47 | vfsuid_t vfsuid = i_uid_into_vfsuid(mnt_userns, inode); |
48 | vfsgid_t vfsgid = i_gid_into_vfsgid(mnt_userns, inode); | |
49 | ||
1da177e4 LT |
50 | stat->dev = inode->i_sb->s_dev; |
51 | stat->ino = inode->i_ino; | |
52 | stat->mode = inode->i_mode; | |
53 | stat->nlink = inode->i_nlink; | |
a2bd096f CB |
54 | stat->uid = vfsuid_into_kuid(vfsuid); |
55 | stat->gid = vfsgid_into_kgid(vfsgid); | |
1da177e4 | 56 | stat->rdev = inode->i_rdev; |
3ddcd056 | 57 | stat->size = i_size_read(inode); |
1da177e4 LT |
58 | stat->atime = inode->i_atime; |
59 | stat->mtime = inode->i_mtime; | |
60 | stat->ctime = inode->i_ctime; | |
93407472 | 61 | stat->blksize = i_blocksize(inode); |
3ddcd056 | 62 | stat->blocks = inode->i_blocks; |
a528d35e | 63 | } |
1da177e4 LT |
64 | EXPORT_SYMBOL(generic_fillattr); |
65 | ||
4f911138 AG |
66 | /** |
67 | * generic_fill_statx_attr - Fill in the statx attributes from the inode flags | |
68 | * @inode: Inode to use as the source | |
69 | * @stat: Where to fill in the attribute flags | |
70 | * | |
71 | * Fill in the STATX_ATTR_* flags in the kstat structure for properties of the | |
72 | * inode that are published on i_flags and enforced by the VFS. | |
73 | */ | |
74 | void generic_fill_statx_attr(struct inode *inode, struct kstat *stat) | |
75 | { | |
76 | if (inode->i_flags & S_IMMUTABLE) | |
77 | stat->attributes |= STATX_ATTR_IMMUTABLE; | |
78 | if (inode->i_flags & S_APPEND) | |
79 | stat->attributes |= STATX_ATTR_APPEND; | |
80 | stat->attributes_mask |= KSTAT_ATTR_VFS_FLAGS; | |
81 | } | |
82 | EXPORT_SYMBOL(generic_fill_statx_attr); | |
83 | ||
b7a6ec52 BF |
84 | /** |
85 | * vfs_getattr_nosec - getattr without security checks | |
86 | * @path: file to get attributes from | |
87 | * @stat: structure to return attributes in | |
a528d35e | 88 | * @request_mask: STATX_xxx flags indicating what the caller wants |
f2d077ff | 89 | * @query_flags: Query mode (AT_STATX_SYNC_TYPE) |
b7a6ec52 BF |
90 | * |
91 | * Get attributes without calling security_inode_getattr. | |
92 | * | |
93 | * Currently the only caller other than vfs_getattr is internal to the | |
a528d35e DH |
94 | * filehandle lookup code, which uses only the inode number and returns no |
95 | * attributes to any user. Any other code probably wants vfs_getattr. | |
b7a6ec52 | 96 | */ |
a528d35e DH |
97 | int vfs_getattr_nosec(const struct path *path, struct kstat *stat, |
98 | u32 request_mask, unsigned int query_flags) | |
1da177e4 | 99 | { |
549c7297 | 100 | struct user_namespace *mnt_userns; |
bb668734 | 101 | struct inode *inode = d_backing_inode(path->dentry); |
1da177e4 | 102 | |
a528d35e DH |
103 | memset(stat, 0, sizeof(*stat)); |
104 | stat->result_mask |= STATX_BASIC_STATS; | |
f2d077ff | 105 | query_flags &= AT_STATX_SYNC_TYPE; |
801e5237 CH |
106 | |
107 | /* allow the fs to override these if it really wants to */ | |
761e28fa MS |
108 | /* SB_NOATIME means filesystem supplies dummy atime value */ |
109 | if (inode->i_sb->s_flags & SB_NOATIME) | |
801e5237 | 110 | stat->result_mask &= ~STATX_ATIME; |
5afa7e8b TT |
111 | |
112 | /* | |
113 | * Note: If you add another clause to set an attribute flag, please | |
114 | * update attributes_mask below. | |
115 | */ | |
801e5237 CH |
116 | if (IS_AUTOMOUNT(inode)) |
117 | stat->attributes |= STATX_ATTR_AUTOMOUNT; | |
118 | ||
712b2698 IW |
119 | if (IS_DAX(inode)) |
120 | stat->attributes |= STATX_ATTR_DAX; | |
121 | ||
5afa7e8b TT |
122 | stat->attributes_mask |= (STATX_ATTR_AUTOMOUNT | |
123 | STATX_ATTR_DAX); | |
124 | ||
549c7297 | 125 | mnt_userns = mnt_user_ns(path->mnt); |
1da177e4 | 126 | if (inode->i_op->getattr) |
549c7297 CB |
127 | return inode->i_op->getattr(mnt_userns, path, stat, |
128 | request_mask, query_flags); | |
1da177e4 | 129 | |
549c7297 | 130 | generic_fillattr(mnt_userns, inode, stat); |
1da177e4 LT |
131 | return 0; |
132 | } | |
b7a6ec52 BF |
133 | EXPORT_SYMBOL(vfs_getattr_nosec); |
134 | ||
a528d35e DH |
135 | /* |
136 | * vfs_getattr - Get the enhanced basic attributes of a file | |
137 | * @path: The file of interest | |
138 | * @stat: Where to return the statistics | |
139 | * @request_mask: STATX_xxx flags indicating what the caller wants | |
f2d077ff | 140 | * @query_flags: Query mode (AT_STATX_SYNC_TYPE) |
a528d35e DH |
141 | * |
142 | * Ask the filesystem for a file's attributes. The caller must indicate in | |
143 | * request_mask and query_flags to indicate what they want. | |
144 | * | |
145 | * If the file is remote, the filesystem can be forced to update the attributes | |
146 | * from the backing store by passing AT_STATX_FORCE_SYNC in query_flags or can | |
147 | * suppress the update by passing AT_STATX_DONT_SYNC. | |
148 | * | |
149 | * Bits must have been set in request_mask to indicate which attributes the | |
150 | * caller wants retrieving. Any such attribute not requested may be returned | |
151 | * anyway, but the value may be approximate, and, if remote, may not have been | |
152 | * synchronised with the server. | |
153 | * | |
154 | * 0 will be returned on success, and a -ve error code if unsuccessful. | |
155 | */ | |
156 | int vfs_getattr(const struct path *path, struct kstat *stat, | |
157 | u32 request_mask, unsigned int query_flags) | |
b7a6ec52 BF |
158 | { |
159 | int retval; | |
160 | ||
3f7036a0 | 161 | retval = security_inode_getattr(path); |
b7a6ec52 BF |
162 | if (retval) |
163 | return retval; | |
a528d35e | 164 | return vfs_getattr_nosec(path, stat, request_mask, query_flags); |
b7a6ec52 | 165 | } |
1da177e4 LT |
166 | EXPORT_SYMBOL(vfs_getattr); |
167 | ||
a528d35e | 168 | /** |
da9aa5d9 | 169 | * vfs_fstat - Get the basic attributes by file descriptor |
a528d35e DH |
170 | * @fd: The file descriptor referring to the file of interest |
171 | * @stat: The result structure to fill in. | |
a528d35e DH |
172 | * |
173 | * This function is a wrapper around vfs_getattr(). The main difference is | |
174 | * that it uses a file descriptor to determine the file location. | |
175 | * | |
176 | * 0 will be returned on success, and a -ve error code if unsuccessful. | |
177 | */ | |
da9aa5d9 | 178 | int vfs_fstat(int fd, struct kstat *stat) |
1da177e4 | 179 | { |
8c7493aa | 180 | struct fd f; |
da9aa5d9 | 181 | int error; |
8c7493aa EB |
182 | |
183 | f = fdget_raw(fd); | |
da9aa5d9 CH |
184 | if (!f.file) |
185 | return -EBADF; | |
186 | error = vfs_getattr(&f.file->f_path, stat, STATX_BASIC_STATS, 0); | |
187 | fdput(f); | |
1da177e4 LT |
188 | return error; |
189 | } | |
1da177e4 | 190 | |
1b6fe6e0 SR |
191 | int getname_statx_lookup_flags(int flags) |
192 | { | |
193 | int lookup_flags = 0; | |
194 | ||
195 | if (!(flags & AT_SYMLINK_NOFOLLOW)) | |
196 | lookup_flags |= LOOKUP_FOLLOW; | |
197 | if (!(flags & AT_NO_AUTOMOUNT)) | |
198 | lookup_flags |= LOOKUP_AUTOMOUNT; | |
199 | if (flags & AT_EMPTY_PATH) | |
200 | lookup_flags |= LOOKUP_EMPTY; | |
201 | ||
202 | return lookup_flags; | |
203 | } | |
204 | ||
a528d35e DH |
205 | /** |
206 | * vfs_statx - Get basic and extra attributes by filename | |
207 | * @dfd: A file descriptor representing the base dir for a relative filename | |
208 | * @filename: The name of the file of interest | |
209 | * @flags: Flags to control the query | |
210 | * @stat: The result structure to fill in. | |
211 | * @request_mask: STATX_xxx flags indicating what the caller wants | |
212 | * | |
213 | * This function is a wrapper around vfs_getattr(). The main difference is | |
214 | * that it uses a filename and base directory to determine the file location. | |
215 | * Additionally, the use of AT_SYMLINK_NOFOLLOW in flags will prevent a symlink | |
216 | * at the given name from being referenced. | |
217 | * | |
a528d35e DH |
218 | * 0 will be returned on success, and a -ve error code if unsuccessful. |
219 | */ | |
1b6fe6e0 | 220 | static int vfs_statx(int dfd, struct filename *filename, int flags, |
a528d35e | 221 | struct kstat *stat, u32 request_mask) |
0112fc22 | 222 | { |
2eae7a18 | 223 | struct path path; |
1b6fe6e0 | 224 | unsigned int lookup_flags = getname_statx_lookup_flags(flags); |
b3f05150 | 225 | int error; |
0112fc22 | 226 | |
b3f05150 | 227 | if (flags & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT | AT_EMPTY_PATH | |
f2d077ff | 228 | AT_STATX_SYNC_TYPE)) |
a528d35e | 229 | return -EINVAL; |
b3f05150 | 230 | |
836fb7e7 | 231 | retry: |
1b6fe6e0 | 232 | error = filename_lookup(dfd, filename, lookup_flags, &path, NULL); |
2eae7a18 CH |
233 | if (error) |
234 | goto out; | |
235 | ||
a528d35e | 236 | error = vfs_getattr(&path, stat, request_mask, flags); |
2d985f8c | 237 | |
fa2fcf4f MS |
238 | stat->mnt_id = real_mount(path.mnt)->mnt_id; |
239 | stat->result_mask |= STATX_MNT_ID; | |
2d985f8c | 240 | |
80340fe3 MS |
241 | if (path.mnt->mnt_root == path.dentry) |
242 | stat->attributes |= STATX_ATTR_MOUNT_ROOT; | |
243 | stat->attributes_mask |= STATX_ATTR_MOUNT_ROOT; | |
2d985f8c EB |
244 | |
245 | /* Handle STATX_DIOALIGN for block devices. */ | |
246 | if (request_mask & STATX_DIOALIGN) { | |
247 | struct inode *inode = d_backing_inode(path.dentry); | |
248 | ||
249 | if (S_ISBLK(inode->i_mode)) | |
250 | bdev_statx_dioalign(inode, stat); | |
251 | } | |
252 | ||
2eae7a18 | 253 | path_put(&path); |
836fb7e7 JL |
254 | if (retry_estale(error, lookup_flags)) { |
255 | lookup_flags |= LOOKUP_REVAL; | |
256 | goto retry; | |
257 | } | |
0112fc22 OD |
258 | out: |
259 | return error; | |
260 | } | |
2eae7a18 | 261 | |
09f1bde4 CH |
262 | int vfs_fstatat(int dfd, const char __user *filename, |
263 | struct kstat *stat, int flags) | |
264 | { | |
1b6fe6e0 SR |
265 | int ret; |
266 | int statx_flags = flags | AT_NO_AUTOMOUNT; | |
267 | struct filename *name; | |
268 | ||
269 | name = getname_flags(filename, getname_statx_lookup_flags(statx_flags), NULL); | |
270 | ret = vfs_statx(dfd, name, statx_flags, stat, STATX_BASIC_STATS); | |
271 | putname(name); | |
272 | ||
273 | return ret; | |
09f1bde4 | 274 | } |
0112fc22 | 275 | |
1da177e4 LT |
276 | #ifdef __ARCH_WANT_OLD_STAT |
277 | ||
278 | /* | |
279 | * For backward compatibility? Maybe this should be moved | |
280 | * into arch/i386 instead? | |
281 | */ | |
282 | static int cp_old_stat(struct kstat *stat, struct __old_kernel_stat __user * statbuf) | |
283 | { | |
284 | static int warncount = 5; | |
285 | struct __old_kernel_stat tmp; | |
a528d35e | 286 | |
1da177e4 LT |
287 | if (warncount > 0) { |
288 | warncount--; | |
289 | printk(KERN_WARNING "VFS: Warning: %s using old stat() call. Recompile your binary.\n", | |
290 | current->comm); | |
291 | } else if (warncount < 0) { | |
292 | /* it's laughable, but... */ | |
293 | warncount = 0; | |
294 | } | |
295 | ||
296 | memset(&tmp, 0, sizeof(struct __old_kernel_stat)); | |
297 | tmp.st_dev = old_encode_dev(stat->dev); | |
298 | tmp.st_ino = stat->ino; | |
afefdbb2 DH |
299 | if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino) |
300 | return -EOVERFLOW; | |
1da177e4 LT |
301 | tmp.st_mode = stat->mode; |
302 | tmp.st_nlink = stat->nlink; | |
303 | if (tmp.st_nlink != stat->nlink) | |
304 | return -EOVERFLOW; | |
a7c1938e EB |
305 | SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid)); |
306 | SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid)); | |
1da177e4 LT |
307 | tmp.st_rdev = old_encode_dev(stat->rdev); |
308 | #if BITS_PER_LONG == 32 | |
309 | if (stat->size > MAX_NON_LFS) | |
310 | return -EOVERFLOW; | |
a528d35e | 311 | #endif |
1da177e4 LT |
312 | tmp.st_size = stat->size; |
313 | tmp.st_atime = stat->atime.tv_sec; | |
314 | tmp.st_mtime = stat->mtime.tv_sec; | |
315 | tmp.st_ctime = stat->ctime.tv_sec; | |
316 | return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0; | |
317 | } | |
318 | ||
c7887325 DH |
319 | SYSCALL_DEFINE2(stat, const char __user *, filename, |
320 | struct __old_kernel_stat __user *, statbuf) | |
1da177e4 LT |
321 | { |
322 | struct kstat stat; | |
2eae7a18 | 323 | int error; |
1da177e4 | 324 | |
2eae7a18 CH |
325 | error = vfs_stat(filename, &stat); |
326 | if (error) | |
327 | return error; | |
1da177e4 | 328 | |
2eae7a18 | 329 | return cp_old_stat(&stat, statbuf); |
1da177e4 | 330 | } |
257ac264 | 331 | |
c7887325 DH |
332 | SYSCALL_DEFINE2(lstat, const char __user *, filename, |
333 | struct __old_kernel_stat __user *, statbuf) | |
1da177e4 LT |
334 | { |
335 | struct kstat stat; | |
2eae7a18 | 336 | int error; |
1da177e4 | 337 | |
2eae7a18 CH |
338 | error = vfs_lstat(filename, &stat); |
339 | if (error) | |
340 | return error; | |
1da177e4 | 341 | |
2eae7a18 | 342 | return cp_old_stat(&stat, statbuf); |
1da177e4 | 343 | } |
257ac264 HC |
344 | |
345 | SYSCALL_DEFINE2(fstat, unsigned int, fd, struct __old_kernel_stat __user *, statbuf) | |
1da177e4 LT |
346 | { |
347 | struct kstat stat; | |
348 | int error = vfs_fstat(fd, &stat); | |
349 | ||
350 | if (!error) | |
351 | error = cp_old_stat(&stat, statbuf); | |
352 | ||
353 | return error; | |
354 | } | |
355 | ||
356 | #endif /* __ARCH_WANT_OLD_STAT */ | |
357 | ||
82b355d1 AB |
358 | #ifdef __ARCH_WANT_NEW_STAT |
359 | ||
a52dd971 LT |
360 | #if BITS_PER_LONG == 32 |
361 | # define choose_32_64(a,b) a | |
362 | #else | |
363 | # define choose_32_64(a,b) b | |
364 | #endif | |
365 | ||
8529f613 LT |
366 | #ifndef INIT_STRUCT_STAT_PADDING |
367 | # define INIT_STRUCT_STAT_PADDING(st) memset(&st, 0, sizeof(st)) | |
368 | #endif | |
369 | ||
1da177e4 LT |
370 | static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf) |
371 | { | |
372 | struct stat tmp; | |
373 | ||
932aba1e MP |
374 | if (sizeof(tmp.st_dev) < 4 && !old_valid_dev(stat->dev)) |
375 | return -EOVERFLOW; | |
376 | if (sizeof(tmp.st_rdev) < 4 && !old_valid_dev(stat->rdev)) | |
1da177e4 | 377 | return -EOVERFLOW; |
a52dd971 LT |
378 | #if BITS_PER_LONG == 32 |
379 | if (stat->size > MAX_NON_LFS) | |
1da177e4 LT |
380 | return -EOVERFLOW; |
381 | #endif | |
382 | ||
8529f613 | 383 | INIT_STRUCT_STAT_PADDING(tmp); |
932aba1e | 384 | tmp.st_dev = new_encode_dev(stat->dev); |
1da177e4 | 385 | tmp.st_ino = stat->ino; |
afefdbb2 DH |
386 | if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino) |
387 | return -EOVERFLOW; | |
1da177e4 LT |
388 | tmp.st_mode = stat->mode; |
389 | tmp.st_nlink = stat->nlink; | |
390 | if (tmp.st_nlink != stat->nlink) | |
391 | return -EOVERFLOW; | |
a7c1938e EB |
392 | SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid)); |
393 | SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid)); | |
932aba1e | 394 | tmp.st_rdev = new_encode_dev(stat->rdev); |
1da177e4 LT |
395 | tmp.st_size = stat->size; |
396 | tmp.st_atime = stat->atime.tv_sec; | |
397 | tmp.st_mtime = stat->mtime.tv_sec; | |
398 | tmp.st_ctime = stat->ctime.tv_sec; | |
399 | #ifdef STAT_HAVE_NSEC | |
400 | tmp.st_atime_nsec = stat->atime.tv_nsec; | |
401 | tmp.st_mtime_nsec = stat->mtime.tv_nsec; | |
402 | tmp.st_ctime_nsec = stat->ctime.tv_nsec; | |
403 | #endif | |
404 | tmp.st_blocks = stat->blocks; | |
405 | tmp.st_blksize = stat->blksize; | |
406 | return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0; | |
407 | } | |
408 | ||
c7887325 DH |
409 | SYSCALL_DEFINE2(newstat, const char __user *, filename, |
410 | struct stat __user *, statbuf) | |
5590ff0d UD |
411 | { |
412 | struct kstat stat; | |
2eae7a18 | 413 | int error = vfs_stat(filename, &stat); |
5590ff0d | 414 | |
2eae7a18 CH |
415 | if (error) |
416 | return error; | |
417 | return cp_new_stat(&stat, statbuf); | |
5590ff0d UD |
418 | } |
419 | ||
c7887325 DH |
420 | SYSCALL_DEFINE2(newlstat, const char __user *, filename, |
421 | struct stat __user *, statbuf) | |
1da177e4 LT |
422 | { |
423 | struct kstat stat; | |
2eae7a18 | 424 | int error; |
1da177e4 | 425 | |
2eae7a18 CH |
426 | error = vfs_lstat(filename, &stat); |
427 | if (error) | |
428 | return error; | |
1da177e4 | 429 | |
2eae7a18 | 430 | return cp_new_stat(&stat, statbuf); |
1da177e4 | 431 | } |
5590ff0d | 432 | |
2833c28a | 433 | #if !defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_SYS_NEWFSTATAT) |
c7887325 | 434 | SYSCALL_DEFINE4(newfstatat, int, dfd, const char __user *, filename, |
6559eed8 | 435 | struct stat __user *, statbuf, int, flag) |
1da177e4 LT |
436 | { |
437 | struct kstat stat; | |
0112fc22 | 438 | int error; |
1da177e4 | 439 | |
0112fc22 OD |
440 | error = vfs_fstatat(dfd, filename, &stat, flag); |
441 | if (error) | |
442 | return error; | |
443 | return cp_new_stat(&stat, statbuf); | |
1da177e4 | 444 | } |
cff2b760 | 445 | #endif |
5590ff0d | 446 | |
257ac264 | 447 | SYSCALL_DEFINE2(newfstat, unsigned int, fd, struct stat __user *, statbuf) |
1da177e4 LT |
448 | { |
449 | struct kstat stat; | |
450 | int error = vfs_fstat(fd, &stat); | |
451 | ||
452 | if (!error) | |
453 | error = cp_new_stat(&stat, statbuf); | |
454 | ||
455 | return error; | |
456 | } | |
82b355d1 | 457 | #endif |
1da177e4 | 458 | |
2dae0248 DB |
459 | static int do_readlinkat(int dfd, const char __user *pathname, |
460 | char __user *buf, int bufsiz) | |
1da177e4 | 461 | { |
2d8f3038 | 462 | struct path path; |
1da177e4 | 463 | int error; |
1fa1e7f6 | 464 | int empty = 0; |
7955119e | 465 | unsigned int lookup_flags = LOOKUP_EMPTY; |
1da177e4 LT |
466 | |
467 | if (bufsiz <= 0) | |
468 | return -EINVAL; | |
469 | ||
7955119e JL |
470 | retry: |
471 | error = user_path_at_empty(dfd, pathname, lookup_flags, &path, &empty); | |
1da177e4 | 472 | if (!error) { |
bb668734 | 473 | struct inode *inode = d_backing_inode(path.dentry); |
1da177e4 | 474 | |
1fa1e7f6 | 475 | error = empty ? -ENOENT : -EINVAL; |
fd4a0edf MS |
476 | /* |
477 | * AFS mountpoints allow readlink(2) but are not symlinks | |
478 | */ | |
479 | if (d_is_symlink(path.dentry) || inode->i_op->readlink) { | |
2d8f3038 | 480 | error = security_inode_readlink(path.dentry); |
1da177e4 | 481 | if (!error) { |
68ac1234 | 482 | touch_atime(&path); |
fd4a0edf | 483 | error = vfs_readlink(path.dentry, buf, bufsiz); |
1da177e4 LT |
484 | } |
485 | } | |
2d8f3038 | 486 | path_put(&path); |
7955119e JL |
487 | if (retry_estale(error, lookup_flags)) { |
488 | lookup_flags |= LOOKUP_REVAL; | |
489 | goto retry; | |
490 | } | |
1da177e4 LT |
491 | } |
492 | return error; | |
493 | } | |
494 | ||
2dae0248 DB |
495 | SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname, |
496 | char __user *, buf, int, bufsiz) | |
497 | { | |
498 | return do_readlinkat(dfd, pathname, buf, bufsiz); | |
499 | } | |
500 | ||
002c8976 HC |
501 | SYSCALL_DEFINE3(readlink, const char __user *, path, char __user *, buf, |
502 | int, bufsiz) | |
5590ff0d | 503 | { |
2dae0248 | 504 | return do_readlinkat(AT_FDCWD, path, buf, bufsiz); |
5590ff0d UD |
505 | } |
506 | ||
1da177e4 LT |
507 | |
508 | /* ---------- LFS-64 ----------- */ | |
0753f70f | 509 | #if defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_COMPAT_STAT64) |
1da177e4 | 510 | |
8529f613 LT |
511 | #ifndef INIT_STRUCT_STAT64_PADDING |
512 | # define INIT_STRUCT_STAT64_PADDING(st) memset(&st, 0, sizeof(st)) | |
513 | #endif | |
514 | ||
1da177e4 LT |
515 | static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf) |
516 | { | |
517 | struct stat64 tmp; | |
518 | ||
8529f613 | 519 | INIT_STRUCT_STAT64_PADDING(tmp); |
1da177e4 LT |
520 | #ifdef CONFIG_MIPS |
521 | /* mips has weird padding, so we don't get 64 bits there */ | |
1da177e4 LT |
522 | tmp.st_dev = new_encode_dev(stat->dev); |
523 | tmp.st_rdev = new_encode_dev(stat->rdev); | |
524 | #else | |
525 | tmp.st_dev = huge_encode_dev(stat->dev); | |
526 | tmp.st_rdev = huge_encode_dev(stat->rdev); | |
527 | #endif | |
528 | tmp.st_ino = stat->ino; | |
afefdbb2 DH |
529 | if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino) |
530 | return -EOVERFLOW; | |
1da177e4 LT |
531 | #ifdef STAT64_HAS_BROKEN_ST_INO |
532 | tmp.__st_ino = stat->ino; | |
533 | #endif | |
534 | tmp.st_mode = stat->mode; | |
535 | tmp.st_nlink = stat->nlink; | |
a7c1938e EB |
536 | tmp.st_uid = from_kuid_munged(current_user_ns(), stat->uid); |
537 | tmp.st_gid = from_kgid_munged(current_user_ns(), stat->gid); | |
1da177e4 LT |
538 | tmp.st_atime = stat->atime.tv_sec; |
539 | tmp.st_atime_nsec = stat->atime.tv_nsec; | |
540 | tmp.st_mtime = stat->mtime.tv_sec; | |
541 | tmp.st_mtime_nsec = stat->mtime.tv_nsec; | |
542 | tmp.st_ctime = stat->ctime.tv_sec; | |
543 | tmp.st_ctime_nsec = stat->ctime.tv_nsec; | |
544 | tmp.st_size = stat->size; | |
545 | tmp.st_blocks = stat->blocks; | |
546 | tmp.st_blksize = stat->blksize; | |
547 | return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0; | |
548 | } | |
549 | ||
c7887325 DH |
550 | SYSCALL_DEFINE2(stat64, const char __user *, filename, |
551 | struct stat64 __user *, statbuf) | |
1da177e4 LT |
552 | { |
553 | struct kstat stat; | |
554 | int error = vfs_stat(filename, &stat); | |
555 | ||
556 | if (!error) | |
557 | error = cp_new_stat64(&stat, statbuf); | |
558 | ||
559 | return error; | |
560 | } | |
257ac264 | 561 | |
c7887325 DH |
562 | SYSCALL_DEFINE2(lstat64, const char __user *, filename, |
563 | struct stat64 __user *, statbuf) | |
1da177e4 LT |
564 | { |
565 | struct kstat stat; | |
566 | int error = vfs_lstat(filename, &stat); | |
567 | ||
568 | if (!error) | |
569 | error = cp_new_stat64(&stat, statbuf); | |
570 | ||
571 | return error; | |
572 | } | |
257ac264 HC |
573 | |
574 | SYSCALL_DEFINE2(fstat64, unsigned long, fd, struct stat64 __user *, statbuf) | |
1da177e4 LT |
575 | { |
576 | struct kstat stat; | |
577 | int error = vfs_fstat(fd, &stat); | |
578 | ||
579 | if (!error) | |
580 | error = cp_new_stat64(&stat, statbuf); | |
581 | ||
582 | return error; | |
583 | } | |
584 | ||
c7887325 | 585 | SYSCALL_DEFINE4(fstatat64, int, dfd, const char __user *, filename, |
6559eed8 | 586 | struct stat64 __user *, statbuf, int, flag) |
cff2b760 UD |
587 | { |
588 | struct kstat stat; | |
0112fc22 | 589 | int error; |
cff2b760 | 590 | |
0112fc22 OD |
591 | error = vfs_fstatat(dfd, filename, &stat, flag); |
592 | if (error) | |
593 | return error; | |
594 | return cp_new_stat64(&stat, statbuf); | |
cff2b760 | 595 | } |
0753f70f | 596 | #endif /* __ARCH_WANT_STAT64 || __ARCH_WANT_COMPAT_STAT64 */ |
1da177e4 | 597 | |
6f88cc17 | 598 | static noinline_for_stack int |
64bd7204 | 599 | cp_statx(const struct kstat *stat, struct statx __user *buffer) |
a528d35e | 600 | { |
64bd7204 EB |
601 | struct statx tmp; |
602 | ||
603 | memset(&tmp, 0, sizeof(tmp)); | |
604 | ||
605 | tmp.stx_mask = stat->result_mask; | |
606 | tmp.stx_blksize = stat->blksize; | |
607 | tmp.stx_attributes = stat->attributes; | |
608 | tmp.stx_nlink = stat->nlink; | |
609 | tmp.stx_uid = from_kuid_munged(current_user_ns(), stat->uid); | |
610 | tmp.stx_gid = from_kgid_munged(current_user_ns(), stat->gid); | |
611 | tmp.stx_mode = stat->mode; | |
612 | tmp.stx_ino = stat->ino; | |
613 | tmp.stx_size = stat->size; | |
614 | tmp.stx_blocks = stat->blocks; | |
3209f68b | 615 | tmp.stx_attributes_mask = stat->attributes_mask; |
64bd7204 EB |
616 | tmp.stx_atime.tv_sec = stat->atime.tv_sec; |
617 | tmp.stx_atime.tv_nsec = stat->atime.tv_nsec; | |
618 | tmp.stx_btime.tv_sec = stat->btime.tv_sec; | |
619 | tmp.stx_btime.tv_nsec = stat->btime.tv_nsec; | |
620 | tmp.stx_ctime.tv_sec = stat->ctime.tv_sec; | |
621 | tmp.stx_ctime.tv_nsec = stat->ctime.tv_nsec; | |
622 | tmp.stx_mtime.tv_sec = stat->mtime.tv_sec; | |
623 | tmp.stx_mtime.tv_nsec = stat->mtime.tv_nsec; | |
624 | tmp.stx_rdev_major = MAJOR(stat->rdev); | |
625 | tmp.stx_rdev_minor = MINOR(stat->rdev); | |
626 | tmp.stx_dev_major = MAJOR(stat->dev); | |
627 | tmp.stx_dev_minor = MINOR(stat->dev); | |
fa2fcf4f | 628 | tmp.stx_mnt_id = stat->mnt_id; |
825cf206 EB |
629 | tmp.stx_dio_mem_align = stat->dio_mem_align; |
630 | tmp.stx_dio_offset_align = stat->dio_offset_align; | |
64bd7204 EB |
631 | |
632 | return copy_to_user(buffer, &tmp, sizeof(tmp)) ? -EFAULT : 0; | |
a528d35e DH |
633 | } |
634 | ||
1b6fe6e0 | 635 | int do_statx(int dfd, struct filename *filename, unsigned int flags, |
0018784f BM |
636 | unsigned int mask, struct statx __user *buffer) |
637 | { | |
638 | struct kstat stat; | |
639 | int error; | |
640 | ||
641 | if (mask & STATX__RESERVED) | |
642 | return -EINVAL; | |
643 | if ((flags & AT_STATX_SYNC_TYPE) == AT_STATX_SYNC_TYPE) | |
644 | return -EINVAL; | |
645 | ||
646 | error = vfs_statx(dfd, filename, flags, &stat, mask); | |
647 | if (error) | |
648 | return error; | |
649 | ||
650 | return cp_statx(&stat, buffer); | |
651 | } | |
652 | ||
a528d35e DH |
653 | /** |
654 | * sys_statx - System call to get enhanced stats | |
655 | * @dfd: Base directory to pathwalk from *or* fd to stat. | |
1e2f82d1 | 656 | * @filename: File to stat or "" with AT_EMPTY_PATH |
a528d35e DH |
657 | * @flags: AT_* flags to control pathwalk. |
658 | * @mask: Parts of statx struct actually required. | |
659 | * @buffer: Result buffer. | |
660 | * | |
1e2f82d1 DH |
661 | * Note that fstat() can be emulated by setting dfd to the fd of interest, |
662 | * supplying "" as the filename and setting AT_EMPTY_PATH in the flags. | |
a528d35e DH |
663 | */ |
664 | SYSCALL_DEFINE5(statx, | |
665 | int, dfd, const char __user *, filename, unsigned, flags, | |
666 | unsigned int, mask, | |
667 | struct statx __user *, buffer) | |
668 | { | |
1b6fe6e0 SR |
669 | int ret; |
670 | struct filename *name; | |
671 | ||
672 | name = getname_flags(filename, getname_statx_lookup_flags(flags), NULL); | |
673 | ret = do_statx(dfd, name, flags, mask, buffer); | |
674 | putname(name); | |
675 | ||
676 | return ret; | |
a528d35e DH |
677 | } |
678 | ||
f18ed30d | 679 | #if defined(CONFIG_COMPAT) && defined(__ARCH_WANT_COMPAT_STAT) |
ac565de3 AV |
680 | static int cp_compat_stat(struct kstat *stat, struct compat_stat __user *ubuf) |
681 | { | |
682 | struct compat_stat tmp; | |
683 | ||
932aba1e MP |
684 | if (sizeof(tmp.st_dev) < 4 && !old_valid_dev(stat->dev)) |
685 | return -EOVERFLOW; | |
686 | if (sizeof(tmp.st_rdev) < 4 && !old_valid_dev(stat->rdev)) | |
ac565de3 AV |
687 | return -EOVERFLOW; |
688 | ||
689 | memset(&tmp, 0, sizeof(tmp)); | |
932aba1e | 690 | tmp.st_dev = new_encode_dev(stat->dev); |
ac565de3 AV |
691 | tmp.st_ino = stat->ino; |
692 | if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino) | |
693 | return -EOVERFLOW; | |
694 | tmp.st_mode = stat->mode; | |
695 | tmp.st_nlink = stat->nlink; | |
696 | if (tmp.st_nlink != stat->nlink) | |
697 | return -EOVERFLOW; | |
698 | SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid)); | |
699 | SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid)); | |
932aba1e | 700 | tmp.st_rdev = new_encode_dev(stat->rdev); |
ac565de3 AV |
701 | if ((u64) stat->size > MAX_NON_LFS) |
702 | return -EOVERFLOW; | |
703 | tmp.st_size = stat->size; | |
704 | tmp.st_atime = stat->atime.tv_sec; | |
705 | tmp.st_atime_nsec = stat->atime.tv_nsec; | |
706 | tmp.st_mtime = stat->mtime.tv_sec; | |
707 | tmp.st_mtime_nsec = stat->mtime.tv_nsec; | |
708 | tmp.st_ctime = stat->ctime.tv_sec; | |
709 | tmp.st_ctime_nsec = stat->ctime.tv_nsec; | |
710 | tmp.st_blocks = stat->blocks; | |
711 | tmp.st_blksize = stat->blksize; | |
712 | return copy_to_user(ubuf, &tmp, sizeof(tmp)) ? -EFAULT : 0; | |
713 | } | |
714 | ||
715 | COMPAT_SYSCALL_DEFINE2(newstat, const char __user *, filename, | |
716 | struct compat_stat __user *, statbuf) | |
717 | { | |
718 | struct kstat stat; | |
719 | int error; | |
720 | ||
721 | error = vfs_stat(filename, &stat); | |
722 | if (error) | |
723 | return error; | |
724 | return cp_compat_stat(&stat, statbuf); | |
725 | } | |
726 | ||
727 | COMPAT_SYSCALL_DEFINE2(newlstat, const char __user *, filename, | |
728 | struct compat_stat __user *, statbuf) | |
729 | { | |
730 | struct kstat stat; | |
731 | int error; | |
732 | ||
733 | error = vfs_lstat(filename, &stat); | |
734 | if (error) | |
735 | return error; | |
736 | return cp_compat_stat(&stat, statbuf); | |
737 | } | |
738 | ||
739 | #ifndef __ARCH_WANT_STAT64 | |
740 | COMPAT_SYSCALL_DEFINE4(newfstatat, unsigned int, dfd, | |
741 | const char __user *, filename, | |
742 | struct compat_stat __user *, statbuf, int, flag) | |
743 | { | |
744 | struct kstat stat; | |
745 | int error; | |
746 | ||
747 | error = vfs_fstatat(dfd, filename, &stat, flag); | |
748 | if (error) | |
749 | return error; | |
750 | return cp_compat_stat(&stat, statbuf); | |
751 | } | |
752 | #endif | |
753 | ||
754 | COMPAT_SYSCALL_DEFINE2(newfstat, unsigned int, fd, | |
755 | struct compat_stat __user *, statbuf) | |
756 | { | |
757 | struct kstat stat; | |
758 | int error = vfs_fstat(fd, &stat); | |
759 | ||
760 | if (!error) | |
761 | error = cp_compat_stat(&stat, statbuf); | |
762 | return error; | |
763 | } | |
764 | #endif | |
765 | ||
b462707e DM |
766 | /* Caller is here responsible for sufficient locking (ie. inode->i_lock) */ |
767 | void __inode_add_bytes(struct inode *inode, loff_t bytes) | |
1da177e4 | 768 | { |
1da177e4 LT |
769 | inode->i_blocks += bytes >> 9; |
770 | bytes &= 511; | |
771 | inode->i_bytes += bytes; | |
772 | if (inode->i_bytes >= 512) { | |
773 | inode->i_blocks++; | |
774 | inode->i_bytes -= 512; | |
775 | } | |
b462707e | 776 | } |
eb315d2a | 777 | EXPORT_SYMBOL(__inode_add_bytes); |
b462707e DM |
778 | |
779 | void inode_add_bytes(struct inode *inode, loff_t bytes) | |
780 | { | |
781 | spin_lock(&inode->i_lock); | |
782 | __inode_add_bytes(inode, bytes); | |
1da177e4 LT |
783 | spin_unlock(&inode->i_lock); |
784 | } | |
785 | ||
786 | EXPORT_SYMBOL(inode_add_bytes); | |
787 | ||
1c8924eb | 788 | void __inode_sub_bytes(struct inode *inode, loff_t bytes) |
1da177e4 | 789 | { |
1da177e4 LT |
790 | inode->i_blocks -= bytes >> 9; |
791 | bytes &= 511; | |
792 | if (inode->i_bytes < bytes) { | |
793 | inode->i_blocks--; | |
794 | inode->i_bytes += 512; | |
795 | } | |
796 | inode->i_bytes -= bytes; | |
1c8924eb JK |
797 | } |
798 | ||
799 | EXPORT_SYMBOL(__inode_sub_bytes); | |
800 | ||
801 | void inode_sub_bytes(struct inode *inode, loff_t bytes) | |
802 | { | |
803 | spin_lock(&inode->i_lock); | |
804 | __inode_sub_bytes(inode, bytes); | |
1da177e4 LT |
805 | spin_unlock(&inode->i_lock); |
806 | } | |
807 | ||
808 | EXPORT_SYMBOL(inode_sub_bytes); | |
809 | ||
810 | loff_t inode_get_bytes(struct inode *inode) | |
811 | { | |
812 | loff_t ret; | |
813 | ||
814 | spin_lock(&inode->i_lock); | |
f4a8116a | 815 | ret = __inode_get_bytes(inode); |
1da177e4 LT |
816 | spin_unlock(&inode->i_lock); |
817 | return ret; | |
818 | } | |
819 | ||
820 | EXPORT_SYMBOL(inode_get_bytes); | |
821 | ||
822 | void inode_set_bytes(struct inode *inode, loff_t bytes) | |
823 | { | |
824 | /* Caller is here responsible for sufficient locking | |
825 | * (ie. inode->i_lock) */ | |
826 | inode->i_blocks = bytes >> 9; | |
827 | inode->i_bytes = bytes & 511; | |
828 | } | |
829 | ||
830 | EXPORT_SYMBOL(inode_set_bytes); |