Commit | Line | Data |
---|---|---|
457c8996 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1da177e4 LT |
2 | /* |
3 | * linux/fs/open.c | |
4 | * | |
5 | * Copyright (C) 1991, 1992 Linus Torvalds | |
6 | */ | |
7 | ||
8 | #include <linux/string.h> | |
9 | #include <linux/mm.h> | |
1da177e4 | 10 | #include <linux/file.h> |
9f3acc31 | 11 | #include <linux/fdtable.h> |
0eeca283 | 12 | #include <linux/fsnotify.h> |
1da177e4 | 13 | #include <linux/module.h> |
1da177e4 LT |
14 | #include <linux/tty.h> |
15 | #include <linux/namei.h> | |
16 | #include <linux/backing-dev.h> | |
16f7e0fe | 17 | #include <linux/capability.h> |
086f7316 | 18 | #include <linux/securebits.h> |
1da177e4 LT |
19 | #include <linux/security.h> |
20 | #include <linux/mount.h> | |
5590ff0d | 21 | #include <linux/fcntl.h> |
5a0e3ad6 | 22 | #include <linux/slab.h> |
7c0f6ba6 | 23 | #include <linux/uaccess.h> |
1da177e4 | 24 | #include <linux/fs.h> |
ef3daeda | 25 | #include <linux/personality.h> |
1da177e4 LT |
26 | #include <linux/pagemap.h> |
27 | #include <linux/syscalls.h> | |
ab2af1f5 | 28 | #include <linux/rcupdate.h> |
73241ccc | 29 | #include <linux/audit.h> |
97ac7350 | 30 | #include <linux/falloc.h> |
5ad4e53b | 31 | #include <linux/fs_struct.h> |
b65a9cfc | 32 | #include <linux/ima.h> |
2dfc1cae | 33 | #include <linux/dnotify.h> |
3f6d078d | 34 | #include <linux/compat.h> |
a793d79e | 35 | #include <linux/mnt_idmapping.h> |
1da177e4 | 36 | |
e81e3f4d EP |
37 | #include "internal.h" |
38 | ||
643fe55a CB |
39 | int do_truncate(struct user_namespace *mnt_userns, struct dentry *dentry, |
40 | loff_t length, unsigned int time_attrs, struct file *filp) | |
1da177e4 | 41 | { |
939a9421 | 42 | int ret; |
1da177e4 LT |
43 | struct iattr newattrs; |
44 | ||
45 | /* Not pretty: "inode->i_size" shouldn't really be signed. But it is. */ | |
46 | if (length < 0) | |
47 | return -EINVAL; | |
48 | ||
49 | newattrs.ia_size = length; | |
4a30131e | 50 | newattrs.ia_valid = ATTR_SIZE | time_attrs; |
cc4e69de MS |
51 | if (filp) { |
52 | newattrs.ia_file = filp; | |
53 | newattrs.ia_valid |= ATTR_FILE; | |
54 | } | |
1da177e4 | 55 | |
45f147a1 JK |
56 | /* Remove suid, sgid, and file capabilities on truncate too */ |
57 | ret = dentry_needs_remove_privs(dentry); | |
58 | if (ret < 0) | |
59 | return ret; | |
939a9421 AW |
60 | if (ret) |
61 | newattrs.ia_valid |= ret | ATTR_FORCE; | |
7b82dc0e | 62 | |
5955102c | 63 | inode_lock(dentry->d_inode); |
27ac0ffe | 64 | /* Note any delegations or leases have already been broken: */ |
643fe55a | 65 | ret = notify_change(mnt_userns, dentry, &newattrs, NULL); |
5955102c | 66 | inode_unlock(dentry->d_inode); |
939a9421 | 67 | return ret; |
1da177e4 LT |
68 | } |
69 | ||
7df818b2 | 70 | long vfs_truncate(const struct path *path, loff_t length) |
1da177e4 | 71 | { |
643fe55a | 72 | struct user_namespace *mnt_userns; |
2d8f3038 | 73 | struct inode *inode; |
a02de960 | 74 | long error; |
1da177e4 | 75 | |
a02de960 | 76 | inode = path->dentry->d_inode; |
1da177e4 LT |
77 | |
78 | /* For directories it's -EISDIR, for other non-regulars - -EINVAL */ | |
1da177e4 | 79 | if (S_ISDIR(inode->i_mode)) |
a02de960 | 80 | return -EISDIR; |
1da177e4 | 81 | if (!S_ISREG(inode->i_mode)) |
a02de960 | 82 | return -EINVAL; |
1da177e4 | 83 | |
a02de960 | 84 | error = mnt_want_write(path->mnt); |
1da177e4 | 85 | if (error) |
a02de960 | 86 | goto out; |
1da177e4 | 87 | |
643fe55a CB |
88 | mnt_userns = mnt_user_ns(path->mnt); |
89 | error = inode_permission(mnt_userns, inode, MAY_WRITE); | |
9ac9b847 DH |
90 | if (error) |
91 | goto mnt_drop_write_and_out; | |
1da177e4 LT |
92 | |
93 | error = -EPERM; | |
c82e42da | 94 | if (IS_APPEND(inode)) |
9ac9b847 | 95 | goto mnt_drop_write_and_out; |
1da177e4 | 96 | |
8cf9ee50 | 97 | error = get_write_access(inode); |
1da177e4 | 98 | if (error) |
9ac9b847 | 99 | goto mnt_drop_write_and_out; |
1da177e4 | 100 | |
9700382c | 101 | /* |
102 | * Make sure that there are no leases. get_write_access() protects | |
103 | * against the truncate racing with a lease-granting setlease(). | |
104 | */ | |
8737c930 | 105 | error = break_lease(inode, O_WRONLY); |
1da177e4 | 106 | if (error) |
9700382c | 107 | goto put_write_and_out; |
1da177e4 | 108 | |
f7e33bdb | 109 | error = security_path_truncate(path); |
907f4554 | 110 | if (!error) |
643fe55a | 111 | error = do_truncate(mnt_userns, path->dentry, length, 0, NULL); |
1da177e4 | 112 | |
9700382c | 113 | put_write_and_out: |
8cf9ee50 | 114 | put_write_access(inode); |
9ac9b847 | 115 | mnt_drop_write_and_out: |
a02de960 | 116 | mnt_drop_write(path->mnt); |
1da177e4 LT |
117 | out: |
118 | return error; | |
119 | } | |
a02de960 DH |
120 | EXPORT_SYMBOL_GPL(vfs_truncate); |
121 | ||
df260e21 | 122 | long do_sys_truncate(const char __user *pathname, loff_t length) |
a02de960 | 123 | { |
48f7530d | 124 | unsigned int lookup_flags = LOOKUP_FOLLOW; |
a02de960 DH |
125 | struct path path; |
126 | int error; | |
127 | ||
128 | if (length < 0) /* sorry, but loff_t says... */ | |
129 | return -EINVAL; | |
130 | ||
48f7530d JL |
131 | retry: |
132 | error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path); | |
a02de960 DH |
133 | if (!error) { |
134 | error = vfs_truncate(&path, length); | |
135 | path_put(&path); | |
136 | } | |
48f7530d JL |
137 | if (retry_estale(error, lookup_flags)) { |
138 | lookup_flags |= LOOKUP_REVAL; | |
139 | goto retry; | |
140 | } | |
a02de960 DH |
141 | return error; |
142 | } | |
1da177e4 | 143 | |
4fd8da8d | 144 | SYSCALL_DEFINE2(truncate, const char __user *, path, long, length) |
1da177e4 | 145 | { |
4fd8da8d | 146 | return do_sys_truncate(path, length); |
1da177e4 LT |
147 | } |
148 | ||
3f6d078d AV |
149 | #ifdef CONFIG_COMPAT |
150 | COMPAT_SYSCALL_DEFINE2(truncate, const char __user *, path, compat_off_t, length) | |
151 | { | |
152 | return do_sys_truncate(path, length); | |
153 | } | |
154 | #endif | |
155 | ||
411d9475 | 156 | long do_sys_ftruncate(unsigned int fd, loff_t length, int small) |
1da177e4 | 157 | { |
bf2965d5 | 158 | struct inode *inode; |
1da177e4 | 159 | struct dentry *dentry; |
2903ff01 | 160 | struct fd f; |
1da177e4 LT |
161 | int error; |
162 | ||
163 | error = -EINVAL; | |
164 | if (length < 0) | |
165 | goto out; | |
166 | error = -EBADF; | |
2903ff01 AV |
167 | f = fdget(fd); |
168 | if (!f.file) | |
1da177e4 LT |
169 | goto out; |
170 | ||
171 | /* explicitly opened as large or we are on 64-bit box */ | |
2903ff01 | 172 | if (f.file->f_flags & O_LARGEFILE) |
1da177e4 LT |
173 | small = 0; |
174 | ||
2903ff01 | 175 | dentry = f.file->f_path.dentry; |
1da177e4 LT |
176 | inode = dentry->d_inode; |
177 | error = -EINVAL; | |
2903ff01 | 178 | if (!S_ISREG(inode->i_mode) || !(f.file->f_mode & FMODE_WRITE)) |
1da177e4 LT |
179 | goto out_putf; |
180 | ||
181 | error = -EINVAL; | |
182 | /* Cannot ftruncate over 2^31 bytes without large file support */ | |
183 | if (small && length > MAX_NON_LFS) | |
184 | goto out_putf; | |
185 | ||
186 | error = -EPERM; | |
78757af6 AG |
187 | /* Check IS_APPEND on real upper inode */ |
188 | if (IS_APPEND(file_inode(f.file))) | |
1da177e4 | 189 | goto out_putf; |
14da9200 | 190 | sb_start_write(inode->i_sb); |
f7e33bdb | 191 | error = security_path_truncate(&f.file->f_path); |
1da177e4 | 192 | if (!error) |
643fe55a CB |
193 | error = do_truncate(file_mnt_user_ns(f.file), dentry, length, |
194 | ATTR_MTIME | ATTR_CTIME, f.file); | |
14da9200 | 195 | sb_end_write(inode->i_sb); |
1da177e4 | 196 | out_putf: |
2903ff01 | 197 | fdput(f); |
1da177e4 LT |
198 | out: |
199 | return error; | |
200 | } | |
201 | ||
bdc480e3 | 202 | SYSCALL_DEFINE2(ftruncate, unsigned int, fd, unsigned long, length) |
1da177e4 | 203 | { |
2cf09666 | 204 | return do_sys_ftruncate(fd, length, 1); |
1da177e4 LT |
205 | } |
206 | ||
3f6d078d AV |
207 | #ifdef CONFIG_COMPAT |
208 | COMPAT_SYSCALL_DEFINE2(ftruncate, unsigned int, fd, compat_ulong_t, length) | |
209 | { | |
210 | return do_sys_ftruncate(fd, length, 1); | |
211 | } | |
212 | #endif | |
213 | ||
1da177e4 LT |
214 | /* LFS versions of truncate are only needed on 32 bit machines */ |
215 | #if BITS_PER_LONG == 32 | |
4a0fd5bf | 216 | SYSCALL_DEFINE2(truncate64, const char __user *, path, loff_t, length) |
1da177e4 LT |
217 | { |
218 | return do_sys_truncate(path, length); | |
219 | } | |
220 | ||
4a0fd5bf | 221 | SYSCALL_DEFINE2(ftruncate64, unsigned int, fd, loff_t, length) |
1da177e4 | 222 | { |
2cf09666 | 223 | return do_sys_ftruncate(fd, length, 0); |
1da177e4 | 224 | } |
6673e0c3 | 225 | #endif /* BITS_PER_LONG == 32 */ |
1da177e4 | 226 | |
59c10c52 GR |
227 | #if defined(CONFIG_COMPAT) && defined(__ARCH_WANT_COMPAT_TRUNCATE64) |
228 | COMPAT_SYSCALL_DEFINE3(truncate64, const char __user *, pathname, | |
229 | compat_arg_u64_dual(length)) | |
230 | { | |
231 | return ksys_truncate(pathname, compat_arg_u64_glue(length)); | |
232 | } | |
233 | #endif | |
234 | ||
235 | #if defined(CONFIG_COMPAT) && defined(__ARCH_WANT_COMPAT_FTRUNCATE64) | |
236 | COMPAT_SYSCALL_DEFINE3(ftruncate64, unsigned int, fd, | |
237 | compat_arg_u64_dual(length)) | |
238 | { | |
239 | return ksys_ftruncate(fd, compat_arg_u64_glue(length)); | |
240 | } | |
241 | #endif | |
3e63cbb1 | 242 | |
72c72bdf | 243 | int vfs_fallocate(struct file *file, int mode, loff_t offset, loff_t len) |
97ac7350 | 244 | { |
496ad9aa | 245 | struct inode *inode = file_inode(file); |
3e63cbb1 | 246 | long ret; |
97ac7350 AA |
247 | |
248 | if (offset < 0 || len <= 0) | |
3e63cbb1 | 249 | return -EINVAL; |
97ac7350 AA |
250 | |
251 | /* Return error if mode is not supported */ | |
dd46c787 | 252 | if (mode & ~FALLOC_FL_SUPPORTED_MASK) |
409332b6 LC |
253 | return -EOPNOTSUPP; |
254 | ||
255 | /* Punch hole and zero range are mutually exclusive */ | |
256 | if ((mode & (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_ZERO_RANGE)) == | |
257 | (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_ZERO_RANGE)) | |
79124f18 JB |
258 | return -EOPNOTSUPP; |
259 | ||
260 | /* Punch hole must have keep size set */ | |
261 | if ((mode & FALLOC_FL_PUNCH_HOLE) && | |
262 | !(mode & FALLOC_FL_KEEP_SIZE)) | |
3e63cbb1 | 263 | return -EOPNOTSUPP; |
97ac7350 | 264 | |
00f5e619 NJ |
265 | /* Collapse range should only be used exclusively. */ |
266 | if ((mode & FALLOC_FL_COLLAPSE_RANGE) && | |
267 | (mode & ~FALLOC_FL_COLLAPSE_RANGE)) | |
268 | return -EINVAL; | |
269 | ||
dd46c787 NJ |
270 | /* Insert range should only be used exclusively. */ |
271 | if ((mode & FALLOC_FL_INSERT_RANGE) && | |
272 | (mode & ~FALLOC_FL_INSERT_RANGE)) | |
273 | return -EINVAL; | |
274 | ||
71be6b49 DW |
275 | /* Unshare range should only be used with allocate mode. */ |
276 | if ((mode & FALLOC_FL_UNSHARE_RANGE) && | |
277 | (mode & ~(FALLOC_FL_UNSHARE_RANGE | FALLOC_FL_KEEP_SIZE))) | |
278 | return -EINVAL; | |
279 | ||
97ac7350 | 280 | if (!(file->f_mode & FMODE_WRITE)) |
3e63cbb1 | 281 | return -EBADF; |
1ca551c6 | 282 | |
00f5e619 | 283 | /* |
8fc61d92 | 284 | * We can only allow pure fallocate on append only files |
00f5e619 | 285 | */ |
8fc61d92 | 286 | if ((mode & ~FALLOC_FL_KEEP_SIZE) && IS_APPEND(inode)) |
1ca551c6 MS |
287 | return -EPERM; |
288 | ||
289 | if (IS_IMMUTABLE(inode)) | |
290 | return -EPERM; | |
291 | ||
0790b31b | 292 | /* |
6d2b6170 | 293 | * We cannot allow any fallocate operation on an active swapfile |
0790b31b LC |
294 | */ |
295 | if (IS_SWAPFILE(inode)) | |
6d2b6170 | 296 | return -ETXTBSY; |
0790b31b | 297 | |
97ac7350 AA |
298 | /* |
299 | * Revalidate the write permissions, in case security policy has | |
300 | * changed since the files were opened. | |
301 | */ | |
302 | ret = security_file_permission(file, MAY_WRITE); | |
303 | if (ret) | |
3e63cbb1 | 304 | return ret; |
97ac7350 | 305 | |
97ac7350 | 306 | if (S_ISFIFO(inode->i_mode)) |
3e63cbb1 | 307 | return -ESPIPE; |
97ac7350 | 308 | |
9e79b132 AG |
309 | if (S_ISDIR(inode->i_mode)) |
310 | return -EISDIR; | |
311 | ||
312 | if (!S_ISREG(inode->i_mode) && !S_ISBLK(inode->i_mode)) | |
3e63cbb1 | 313 | return -ENODEV; |
97ac7350 | 314 | |
97ac7350 AA |
315 | /* Check for wrap through zero too */ |
316 | if (((offset + len) > inode->i_sb->s_maxbytes) || ((offset + len) < 0)) | |
3e63cbb1 | 317 | return -EFBIG; |
97ac7350 | 318 | |
2fe17c10 | 319 | if (!file->f_op->fallocate) |
3e63cbb1 | 320 | return -EOPNOTSUPP; |
97ac7350 | 321 | |
bfe219d3 | 322 | file_start_write(file); |
14da9200 | 323 | ret = file->f_op->fallocate(file, mode, offset, len); |
820c12d5 HS |
324 | |
325 | /* | |
326 | * Create inotify and fanotify events. | |
327 | * | |
328 | * To keep the logic simple always create events if fallocate succeeds. | |
329 | * This implies that events are even created if the file size remains | |
330 | * unchanged, e.g. when using flag FALLOC_FL_KEEP_SIZE. | |
331 | */ | |
332 | if (ret == 0) | |
333 | fsnotify_modify(file); | |
334 | ||
bfe219d3 | 335 | file_end_write(file); |
14da9200 | 336 | return ret; |
3e63cbb1 | 337 | } |
72c72bdf | 338 | EXPORT_SYMBOL_GPL(vfs_fallocate); |
3e63cbb1 | 339 | |
edf292c7 | 340 | int ksys_fallocate(int fd, int mode, loff_t offset, loff_t len) |
3e63cbb1 | 341 | { |
2903ff01 | 342 | struct fd f = fdget(fd); |
3e63cbb1 AJ |
343 | int error = -EBADF; |
344 | ||
2903ff01 | 345 | if (f.file) { |
72c72bdf | 346 | error = vfs_fallocate(f.file, mode, offset, len); |
2903ff01 | 347 | fdput(f); |
3e63cbb1 | 348 | } |
3e63cbb1 | 349 | return error; |
97ac7350 | 350 | } |
3e63cbb1 | 351 | |
edf292c7 DB |
352 | SYSCALL_DEFINE4(fallocate, int, fd, int, mode, loff_t, offset, loff_t, len) |
353 | { | |
354 | return ksys_fallocate(fd, mode, offset, len); | |
355 | } | |
356 | ||
59c10c52 GR |
357 | #if defined(CONFIG_COMPAT) && defined(__ARCH_WANT_COMPAT_FALLOCATE) |
358 | COMPAT_SYSCALL_DEFINE6(fallocate, int, fd, int, mode, compat_arg_u64_dual(offset), | |
359 | compat_arg_u64_dual(len)) | |
360 | { | |
361 | return ksys_fallocate(fd, mode, compat_arg_u64_glue(offset), | |
362 | compat_arg_u64_glue(len)); | |
363 | } | |
364 | #endif | |
365 | ||
1da177e4 LT |
366 | /* |
367 | * access() needs to use the real uid/gid, not the effective uid/gid. | |
368 | * We do this by temporarily clearing all FS-related capabilities and | |
369 | * switching the fsuid/fsgid around to the real ones. | |
370 | */ | |
94704515 | 371 | static const struct cred *access_override_creds(void) |
1da177e4 | 372 | { |
d84f4f99 DH |
373 | const struct cred *old_cred; |
374 | struct cred *override_cred; | |
1da177e4 | 375 | |
d84f4f99 DH |
376 | override_cred = prepare_creds(); |
377 | if (!override_cred) | |
94704515 | 378 | return NULL; |
1da177e4 | 379 | |
d84f4f99 DH |
380 | override_cred->fsuid = override_cred->uid; |
381 | override_cred->fsgid = override_cred->gid; | |
1da177e4 | 382 | |
086f7316 | 383 | if (!issecure(SECURE_NO_SETUID_FIXUP)) { |
1cdcbec1 | 384 | /* Clear the capabilities if we switch to a non-root user */ |
18815a18 EB |
385 | kuid_t root_uid = make_kuid(override_cred->user_ns, 0); |
386 | if (!uid_eq(override_cred->uid, root_uid)) | |
d84f4f99 | 387 | cap_clear(override_cred->cap_effective); |
086f7316 | 388 | else |
d84f4f99 DH |
389 | override_cred->cap_effective = |
390 | override_cred->cap_permitted; | |
086f7316 | 391 | } |
1da177e4 | 392 | |
d7852fbd LT |
393 | /* |
394 | * The new set of credentials can *only* be used in | |
395 | * task-synchronous circumstances, and does not need | |
396 | * RCU freeing, unless somebody then takes a separate | |
397 | * reference to it. | |
398 | * | |
399 | * NOTE! This is _only_ true because this credential | |
400 | * is used purely for override_creds() that installs | |
401 | * it as the subjective cred. Other threads will be | |
402 | * accessing ->real_cred, not the subjective cred. | |
403 | * | |
404 | * If somebody _does_ make a copy of this (using the | |
405 | * 'get_current_cred()' function), that will clear the | |
406 | * non_rcu field, because now that other user may be | |
407 | * expecting RCU freeing. But normal thread-synchronous | |
408 | * cred accesses will keep things non-RCY. | |
409 | */ | |
410 | override_cred->non_rcu = 1; | |
411 | ||
d84f4f99 | 412 | old_cred = override_creds(override_cred); |
94704515 MS |
413 | |
414 | /* override_cred() gets its own ref */ | |
415 | put_cred(override_cred); | |
416 | ||
417 | return old_cred; | |
418 | } | |
419 | ||
eb9d7d39 | 420 | static long do_faccessat(int dfd, const char __user *filename, int mode, int flags) |
94704515 MS |
421 | { |
422 | struct path path; | |
423 | struct inode *inode; | |
424 | int res; | |
425 | unsigned int lookup_flags = LOOKUP_FOLLOW; | |
c8ffd8bc | 426 | const struct cred *old_cred = NULL; |
94704515 MS |
427 | |
428 | if (mode & ~S_IRWXO) /* where's F_OK, X_OK, W_OK, R_OK? */ | |
429 | return -EINVAL; | |
430 | ||
c8ffd8bc MS |
431 | if (flags & ~(AT_EACCESS | AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH)) |
432 | return -EINVAL; | |
433 | ||
434 | if (flags & AT_SYMLINK_NOFOLLOW) | |
435 | lookup_flags &= ~LOOKUP_FOLLOW; | |
436 | if (flags & AT_EMPTY_PATH) | |
437 | lookup_flags |= LOOKUP_EMPTY; | |
438 | ||
439 | if (!(flags & AT_EACCESS)) { | |
440 | old_cred = access_override_creds(); | |
441 | if (!old_cred) | |
442 | return -ENOMEM; | |
443 | } | |
94704515 | 444 | |
87fa5595 JL |
445 | retry: |
446 | res = user_path_at(dfd, filename, lookup_flags, &path); | |
6902d925 DH |
447 | if (res) |
448 | goto out; | |
449 | ||
63afdfc7 | 450 | inode = d_backing_inode(path.dentry); |
256984a8 AV |
451 | |
452 | if ((mode & MAY_EXEC) && S_ISREG(inode->i_mode)) { | |
30524472 AV |
453 | /* |
454 | * MAY_EXEC on regular files is denied if the fs is mounted | |
455 | * with the "noexec" flag. | |
456 | */ | |
457 | res = -EACCES; | |
90f8572b | 458 | if (path_noexec(&path)) |
30524472 AV |
459 | goto out_path_release; |
460 | } | |
461 | ||
b8b546a0 | 462 | res = inode_permission(mnt_user_ns(path.mnt), inode, mode | MAY_ACCESS); |
6902d925 | 463 | /* SuS v2 requires we report a read only fs too */ |
256984a8 | 464 | if (res || !(mode & S_IWOTH) || special_file(inode->i_mode)) |
6902d925 | 465 | goto out_path_release; |
2f676cbc DH |
466 | /* |
467 | * This is a rare case where using __mnt_is_readonly() | |
468 | * is OK without a mnt_want/drop_write() pair. Since | |
469 | * no actual write to the fs is performed here, we do | |
470 | * not need to telegraph to that to anyone. | |
471 | * | |
472 | * By doing this, we accept that this access is | |
473 | * inherently racy and know that the fs may change | |
474 | * state before we even see this result. | |
475 | */ | |
2d8f3038 | 476 | if (__mnt_is_readonly(path.mnt)) |
6902d925 | 477 | res = -EROFS; |
1da177e4 | 478 | |
6902d925 | 479 | out_path_release: |
2d8f3038 | 480 | path_put(&path); |
87fa5595 JL |
481 | if (retry_estale(res, lookup_flags)) { |
482 | lookup_flags |= LOOKUP_REVAL; | |
483 | goto retry; | |
484 | } | |
6902d925 | 485 | out: |
c8ffd8bc MS |
486 | if (old_cred) |
487 | revert_creds(old_cred); | |
488 | ||
1da177e4 LT |
489 | return res; |
490 | } | |
491 | ||
cbfe20f5 DB |
492 | SYSCALL_DEFINE3(faccessat, int, dfd, const char __user *, filename, int, mode) |
493 | { | |
c8ffd8bc MS |
494 | return do_faccessat(dfd, filename, mode, 0); |
495 | } | |
496 | ||
497 | SYSCALL_DEFINE4(faccessat2, int, dfd, const char __user *, filename, int, mode, | |
498 | int, flags) | |
499 | { | |
500 | return do_faccessat(dfd, filename, mode, flags); | |
cbfe20f5 DB |
501 | } |
502 | ||
ca013e94 | 503 | SYSCALL_DEFINE2(access, const char __user *, filename, int, mode) |
5590ff0d | 504 | { |
c8ffd8bc | 505 | return do_faccessat(AT_FDCWD, filename, mode, 0); |
5590ff0d UD |
506 | } |
507 | ||
db63f1e3 | 508 | SYSCALL_DEFINE1(chdir, const char __user *, filename) |
1da177e4 | 509 | { |
2d8f3038 | 510 | struct path path; |
1da177e4 | 511 | int error; |
0291c0a5 JL |
512 | unsigned int lookup_flags = LOOKUP_FOLLOW | LOOKUP_DIRECTORY; |
513 | retry: | |
514 | error = user_path_at(AT_FDCWD, filename, lookup_flags, &path); | |
1da177e4 LT |
515 | if (error) |
516 | goto out; | |
517 | ||
02f92b38 | 518 | error = path_permission(&path, MAY_EXEC | MAY_CHDIR); |
1da177e4 LT |
519 | if (error) |
520 | goto dput_and_out; | |
521 | ||
2d8f3038 | 522 | set_fs_pwd(current->fs, &path); |
1da177e4 LT |
523 | |
524 | dput_and_out: | |
2d8f3038 | 525 | path_put(&path); |
0291c0a5 JL |
526 | if (retry_estale(error, lookup_flags)) { |
527 | lookup_flags |= LOOKUP_REVAL; | |
528 | goto retry; | |
529 | } | |
1da177e4 LT |
530 | out: |
531 | return error; | |
532 | } | |
533 | ||
3cdad428 | 534 | SYSCALL_DEFINE1(fchdir, unsigned int, fd) |
1da177e4 | 535 | { |
2903ff01 | 536 | struct fd f = fdget_raw(fd); |
159b0956 | 537 | int error; |
1da177e4 LT |
538 | |
539 | error = -EBADF; | |
2903ff01 | 540 | if (!f.file) |
1da177e4 LT |
541 | goto out; |
542 | ||
1da177e4 | 543 | error = -ENOTDIR; |
159b0956 | 544 | if (!d_can_lookup(f.file->f_path.dentry)) |
1da177e4 LT |
545 | goto out_putf; |
546 | ||
02f92b38 | 547 | error = file_permission(f.file, MAY_EXEC | MAY_CHDIR); |
1da177e4 | 548 | if (!error) |
2903ff01 | 549 | set_fs_pwd(current->fs, &f.file->f_path); |
1da177e4 | 550 | out_putf: |
2903ff01 | 551 | fdput(f); |
1da177e4 LT |
552 | out: |
553 | return error; | |
554 | } | |
555 | ||
4b7ca501 | 556 | SYSCALL_DEFINE1(chroot, const char __user *, filename) |
1da177e4 | 557 | { |
2d8f3038 | 558 | struct path path; |
1da177e4 | 559 | int error; |
2771261e JL |
560 | unsigned int lookup_flags = LOOKUP_FOLLOW | LOOKUP_DIRECTORY; |
561 | retry: | |
562 | error = user_path_at(AT_FDCWD, filename, lookup_flags, &path); | |
1da177e4 LT |
563 | if (error) |
564 | goto out; | |
565 | ||
02f92b38 | 566 | error = path_permission(&path, MAY_EXEC | MAY_CHDIR); |
1da177e4 LT |
567 | if (error) |
568 | goto dput_and_out; | |
569 | ||
570 | error = -EPERM; | |
c7b96acf | 571 | if (!ns_capable(current_user_ns(), CAP_SYS_CHROOT)) |
1da177e4 | 572 | goto dput_and_out; |
8b8efb44 TH |
573 | error = security_path_chroot(&path); |
574 | if (error) | |
575 | goto dput_and_out; | |
1da177e4 | 576 | |
2d8f3038 | 577 | set_fs_root(current->fs, &path); |
1da177e4 LT |
578 | error = 0; |
579 | dput_and_out: | |
2d8f3038 | 580 | path_put(&path); |
2771261e JL |
581 | if (retry_estale(error, lookup_flags)) { |
582 | lookup_flags |= LOOKUP_REVAL; | |
583 | goto retry; | |
584 | } | |
1da177e4 LT |
585 | out: |
586 | return error; | |
587 | } | |
588 | ||
1097742e | 589 | int chmod_common(const struct path *path, umode_t mode) |
1da177e4 | 590 | { |
e57712eb | 591 | struct inode *inode = path->dentry->d_inode; |
27ac0ffe | 592 | struct inode *delegated_inode = NULL; |
1da177e4 | 593 | struct iattr newattrs; |
e57712eb | 594 | int error; |
1da177e4 | 595 | |
e57712eb AV |
596 | error = mnt_want_write(path->mnt); |
597 | if (error) | |
598 | return error; | |
27ac0ffe | 599 | retry_deleg: |
5955102c | 600 | inode_lock(inode); |
cdcf116d | 601 | error = security_path_chmod(path, mode); |
e57712eb | 602 | if (error) |
fe542cf5 | 603 | goto out_unlock; |
1da177e4 LT |
604 | newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO); |
605 | newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; | |
b8b546a0 CB |
606 | error = notify_change(mnt_user_ns(path->mnt), path->dentry, |
607 | &newattrs, &delegated_inode); | |
fe542cf5 | 608 | out_unlock: |
5955102c | 609 | inode_unlock(inode); |
27ac0ffe BF |
610 | if (delegated_inode) { |
611 | error = break_deleg_wait(&delegated_inode); | |
612 | if (!error) | |
613 | goto retry_deleg; | |
614 | } | |
e57712eb AV |
615 | mnt_drop_write(path->mnt); |
616 | return error; | |
617 | } | |
618 | ||
9e96c8c0 CH |
619 | int vfs_fchmod(struct file *file, umode_t mode) |
620 | { | |
621 | audit_file(file); | |
622 | return chmod_common(&file->f_path, mode); | |
623 | } | |
624 | ||
b25ba7c3 | 625 | SYSCALL_DEFINE2(fchmod, unsigned int, fd, umode_t, mode) |
e57712eb | 626 | { |
173c8401 | 627 | struct fd f = fdget(fd); |
e57712eb AV |
628 | int err = -EBADF; |
629 | ||
173c8401 | 630 | if (f.file) { |
9e96c8c0 | 631 | err = vfs_fchmod(f.file, mode); |
173c8401 | 632 | fdput(f); |
e57712eb | 633 | } |
1da177e4 LT |
634 | return err; |
635 | } | |
636 | ||
1097742e | 637 | static int do_fchmodat(int dfd, const char __user *filename, umode_t mode) |
1da177e4 | 638 | { |
2d8f3038 | 639 | struct path path; |
1da177e4 | 640 | int error; |
14ff690c JL |
641 | unsigned int lookup_flags = LOOKUP_FOLLOW; |
642 | retry: | |
643 | error = user_path_at(dfd, filename, lookup_flags, &path); | |
e57712eb AV |
644 | if (!error) { |
645 | error = chmod_common(&path, mode); | |
646 | path_put(&path); | |
14ff690c JL |
647 | if (retry_estale(error, lookup_flags)) { |
648 | lookup_flags |= LOOKUP_REVAL; | |
649 | goto retry; | |
650 | } | |
e57712eb | 651 | } |
1da177e4 LT |
652 | return error; |
653 | } | |
654 | ||
03450e27 DB |
655 | SYSCALL_DEFINE3(fchmodat, int, dfd, const char __user *, filename, |
656 | umode_t, mode) | |
657 | { | |
658 | return do_fchmodat(dfd, filename, mode); | |
659 | } | |
660 | ||
49f0a076 | 661 | SYSCALL_DEFINE2(chmod, const char __user *, filename, umode_t, mode) |
5590ff0d | 662 | { |
03450e27 | 663 | return do_fchmodat(AT_FDCWD, filename, mode); |
5590ff0d UD |
664 | } |
665 | ||
b873498f | 666 | int chown_common(const struct path *path, uid_t user, gid_t group) |
1da177e4 | 667 | { |
bd303368 | 668 | struct user_namespace *mnt_userns, *fs_userns; |
fe542cf5 | 669 | struct inode *inode = path->dentry->d_inode; |
27ac0ffe | 670 | struct inode *delegated_inode = NULL; |
1da177e4 LT |
671 | int error; |
672 | struct iattr newattrs; | |
52137abe EB |
673 | kuid_t uid; |
674 | kgid_t gid; | |
675 | ||
676 | uid = make_kuid(current_user_ns(), user); | |
677 | gid = make_kgid(current_user_ns(), group); | |
1da177e4 | 678 | |
b8b546a0 | 679 | mnt_userns = mnt_user_ns(path->mnt); |
bd303368 CB |
680 | fs_userns = i_user_ns(inode); |
681 | uid = mapped_kuid_user(mnt_userns, fs_userns, uid); | |
682 | gid = mapped_kgid_user(mnt_userns, fs_userns, gid); | |
b8b546a0 | 683 | |
c1b8940b | 684 | retry_deleg: |
1da177e4 LT |
685 | newattrs.ia_valid = ATTR_CTIME; |
686 | if (user != (uid_t) -1) { | |
52137abe EB |
687 | if (!uid_valid(uid)) |
688 | return -EINVAL; | |
1da177e4 | 689 | newattrs.ia_valid |= ATTR_UID; |
52137abe | 690 | newattrs.ia_uid = uid; |
1da177e4 LT |
691 | } |
692 | if (group != (gid_t) -1) { | |
52137abe EB |
693 | if (!gid_valid(gid)) |
694 | return -EINVAL; | |
1da177e4 | 695 | newattrs.ia_valid |= ATTR_GID; |
52137abe | 696 | newattrs.ia_gid = gid; |
1da177e4 LT |
697 | } |
698 | if (!S_ISDIR(inode->i_mode)) | |
b5376771 SH |
699 | newattrs.ia_valid |= |
700 | ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV; | |
5955102c | 701 | inode_lock(inode); |
d2b31ca6 | 702 | error = security_path_chown(path, uid, gid); |
fe542cf5 | 703 | if (!error) |
b8b546a0 | 704 | error = notify_change(mnt_userns, path->dentry, &newattrs, |
2f221d6f | 705 | &delegated_inode); |
5955102c | 706 | inode_unlock(inode); |
27ac0ffe BF |
707 | if (delegated_inode) { |
708 | error = break_deleg_wait(&delegated_inode); | |
709 | if (!error) | |
710 | goto retry_deleg; | |
711 | } | |
1da177e4 LT |
712 | return error; |
713 | } | |
714 | ||
55731b3c DB |
715 | int do_fchownat(int dfd, const char __user *filename, uid_t user, gid_t group, |
716 | int flag) | |
5590ff0d | 717 | { |
2d8f3038 | 718 | struct path path; |
5590ff0d | 719 | int error = -EINVAL; |
65cfc672 | 720 | int lookup_flags; |
5590ff0d | 721 | |
65cfc672 | 722 | if ((flag & ~(AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH)) != 0) |
5590ff0d UD |
723 | goto out; |
724 | ||
65cfc672 AV |
725 | lookup_flags = (flag & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW; |
726 | if (flag & AT_EMPTY_PATH) | |
727 | lookup_flags |= LOOKUP_EMPTY; | |
99a5df37 | 728 | retry: |
65cfc672 | 729 | error = user_path_at(dfd, filename, lookup_flags, &path); |
6902d925 DH |
730 | if (error) |
731 | goto out; | |
2d8f3038 | 732 | error = mnt_want_write(path.mnt); |
2af482a7 DH |
733 | if (error) |
734 | goto out_release; | |
fe542cf5 | 735 | error = chown_common(&path, user, group); |
2d8f3038 | 736 | mnt_drop_write(path.mnt); |
2af482a7 | 737 | out_release: |
2d8f3038 | 738 | path_put(&path); |
99a5df37 JL |
739 | if (retry_estale(error, lookup_flags)) { |
740 | lookup_flags |= LOOKUP_REVAL; | |
741 | goto retry; | |
742 | } | |
5590ff0d UD |
743 | out: |
744 | return error; | |
745 | } | |
746 | ||
55731b3c DB |
747 | SYSCALL_DEFINE5(fchownat, int, dfd, const char __user *, filename, uid_t, user, |
748 | gid_t, group, int, flag) | |
749 | { | |
750 | return do_fchownat(dfd, filename, user, group, flag); | |
751 | } | |
752 | ||
55e4def0 | 753 | SYSCALL_DEFINE3(chown, const char __user *, filename, uid_t, user, gid_t, group) |
1da177e4 | 754 | { |
55731b3c | 755 | return do_fchownat(AT_FDCWD, filename, user, group, 0); |
55e4def0 | 756 | } |
1da177e4 | 757 | |
55e4def0 DH |
758 | SYSCALL_DEFINE3(lchown, const char __user *, filename, uid_t, user, gid_t, group) |
759 | { | |
55731b3c DB |
760 | return do_fchownat(AT_FDCWD, filename, user, group, |
761 | AT_SYMLINK_NOFOLLOW); | |
1da177e4 LT |
762 | } |
763 | ||
c04011fe CH |
764 | int vfs_fchown(struct file *file, uid_t user, gid_t group) |
765 | { | |
766 | int error; | |
767 | ||
768 | error = mnt_want_write_file(file); | |
769 | if (error) | |
770 | return error; | |
771 | audit_file(file); | |
772 | error = chown_common(&file->f_path, user, group); | |
773 | mnt_drop_write_file(file); | |
774 | return error; | |
775 | } | |
776 | ||
55731b3c | 777 | int ksys_fchown(unsigned int fd, uid_t user, gid_t group) |
1da177e4 | 778 | { |
2903ff01 | 779 | struct fd f = fdget(fd); |
1da177e4 LT |
780 | int error = -EBADF; |
781 | ||
c04011fe CH |
782 | if (f.file) { |
783 | error = vfs_fchown(f.file, user, group); | |
784 | fdput(f); | |
785 | } | |
1da177e4 LT |
786 | return error; |
787 | } | |
788 | ||
55731b3c DB |
789 | SYSCALL_DEFINE3(fchown, unsigned int, fd, uid_t, user, gid_t, group) |
790 | { | |
791 | return ksys_fchown(fd, user, group); | |
792 | } | |
793 | ||
02e5180d | 794 | static int do_dentry_open(struct file *f, |
4bacc9c9 | 795 | struct inode *inode, |
ae2bb293 | 796 | int (*open)(struct inode *, struct file *)) |
1da177e4 | 797 | { |
1abf0c71 | 798 | static const struct file_operations empty_fops = {}; |
1da177e4 LT |
799 | int error; |
800 | ||
b5bcdda3 | 801 | path_get(&f->f_path); |
4bacc9c9 | 802 | f->f_inode = inode; |
1da177e4 | 803 | f->f_mapping = inode->i_mapping; |
5660e13d | 804 | f->f_wb_err = filemap_sample_wb_err(f->f_mapping); |
735e4ae5 | 805 | f->f_sb_err = file_sample_sb_err(f); |
5660e13d | 806 | |
3f4d5a00 | 807 | if (unlikely(f->f_flags & O_PATH)) { |
f5d11409 | 808 | f->f_mode = FMODE_PATH | FMODE_OPENED; |
1abf0c71 | 809 | f->f_op = &empty_fops; |
af04fadc | 810 | return 0; |
1abf0c71 AV |
811 | } |
812 | ||
dd20908a | 813 | if (f->f_mode & FMODE_WRITE && !special_file(inode->i_mode)) { |
0ccb2863 | 814 | error = get_write_access(inode); |
3f4d5a00 | 815 | if (unlikely(error)) |
1da177e4 | 816 | goto cleanup_file; |
0ccb2863 | 817 | error = __mnt_want_write(f->f_path.mnt); |
3f4d5a00 | 818 | if (unlikely(error)) { |
0ccb2863 AV |
819 | put_write_access(inode); |
820 | goto cleanup_file; | |
821 | } | |
83f936c7 | 822 | f->f_mode |= FMODE_WRITER; |
1da177e4 LT |
823 | } |
824 | ||
2be7d348 LT |
825 | /* POSIX.1-2008/SUSv4 Section XSI 2.9.7 */ |
826 | if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)) | |
827 | f->f_mode |= FMODE_ATOMIC_POS; | |
828 | ||
1abf0c71 | 829 | f->f_op = fops_get(inode->i_fop); |
7159d544 | 830 | if (WARN_ON(!f->f_op)) { |
72c2d531 AV |
831 | error = -ENODEV; |
832 | goto cleanup_all; | |
833 | } | |
1abf0c71 | 834 | |
e3f20ae2 | 835 | error = security_file_open(f); |
788e7dd4 YN |
836 | if (error) |
837 | goto cleanup_all; | |
838 | ||
c568d683 | 839 | error = break_lease(locks_inode(f), f->f_flags); |
f3c7691e BF |
840 | if (error) |
841 | goto cleanup_all; | |
842 | ||
ea73ea72 AV |
843 | /* normally all 3 are set; ->open() can clear them if needed */ |
844 | f->f_mode |= FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE; | |
72c2d531 | 845 | if (!open) |
834f2a4a TM |
846 | open = f->f_op->open; |
847 | if (open) { | |
848 | error = open(inode, f); | |
1da177e4 LT |
849 | if (error) |
850 | goto cleanup_all; | |
851 | } | |
f5d11409 | 852 | f->f_mode |= FMODE_OPENED; |
890275b5 MZ |
853 | if ((f->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ) |
854 | i_readcount_inc(inode); | |
293bc982 | 855 | if ((f->f_mode & FMODE_READ) && |
84363182 | 856 | likely(f->f_op->read || f->f_op->read_iter)) |
7f7f25e8 | 857 | f->f_mode |= FMODE_CAN_READ; |
293bc982 | 858 | if ((f->f_mode & FMODE_WRITE) && |
84363182 | 859 | likely(f->f_op->write || f->f_op->write_iter)) |
7f7f25e8 | 860 | f->f_mode |= FMODE_CAN_WRITE; |
a2ad63da N |
861 | if (f->f_mapping->a_ops && f->f_mapping->a_ops->direct_IO) |
862 | f->f_mode |= FMODE_CAN_ODIRECT; | |
834f2a4a | 863 | |
1da177e4 LT |
864 | f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC); |
865 | ||
866 | file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping); | |
af04fadc | 867 | |
a2ad63da N |
868 | if ((f->f_flags & O_DIRECT) && !(f->f_mode & FMODE_CAN_ODIRECT)) |
869 | return -EINVAL; | |
09d91cda SL |
870 | |
871 | /* | |
872 | * XXX: Huge page cache doesn't support writing yet. Drop all page | |
873 | * cache for this file before processing writes. | |
874 | */ | |
eb6ecbed CF |
875 | if (f->f_mode & FMODE_WRITE) { |
876 | /* | |
877 | * Paired with smp_mb() in collapse_file() to ensure nr_thps | |
878 | * is up to date and the update to i_writecount by | |
879 | * get_write_access() is visible. Ensures subsequent insertion | |
880 | * of THPs into the page cache will fail. | |
881 | */ | |
882 | smp_mb(); | |
55fc0d91 | 883 | if (filemap_nr_thps(inode->i_mapping)) { |
8468e937 RW |
884 | struct address_space *mapping = inode->i_mapping; |
885 | ||
55fc0d91 | 886 | filemap_invalidate_lock(inode->i_mapping); |
8468e937 RW |
887 | /* |
888 | * unmap_mapping_range just need to be called once | |
889 | * here, because the private pages is not need to be | |
890 | * unmapped mapping (e.g. data segment of dynamic | |
891 | * shared libraries here). | |
892 | */ | |
893 | unmap_mapping_range(mapping, 0, 0, 0); | |
894 | truncate_inode_pages(mapping, 0); | |
55fc0d91 RW |
895 | filemap_invalidate_unlock(inode->i_mapping); |
896 | } | |
eb6ecbed | 897 | } |
09d91cda | 898 | |
96b7e579 | 899 | return 0; |
1da177e4 LT |
900 | |
901 | cleanup_all: | |
6b4e8085 AV |
902 | if (WARN_ON_ONCE(error > 0)) |
903 | error = -EINVAL; | |
1da177e4 | 904 | fops_put(f->f_op); |
83f936c7 | 905 | if (f->f_mode & FMODE_WRITER) { |
1da177e4 | 906 | put_write_access(inode); |
83f936c7 | 907 | __mnt_drop_write(f->f_path.mnt); |
4a3fd211 | 908 | } |
1da177e4 | 909 | cleanup_file: |
02e5180d AV |
910 | path_put(&f->f_path); |
911 | f->f_path.mnt = NULL; | |
912 | f->f_path.dentry = NULL; | |
dd37978c | 913 | f->f_inode = NULL; |
96b7e579 | 914 | return error; |
1da177e4 LT |
915 | } |
916 | ||
d18e9008 MS |
917 | /** |
918 | * finish_open - finish opening a file | |
0854d450 | 919 | * @file: file pointer |
d18e9008 MS |
920 | * @dentry: pointer to dentry |
921 | * @open: open callback | |
0854d450 | 922 | * @opened: state of open |
d18e9008 MS |
923 | * |
924 | * This can be used to finish opening a file passed to i_op->atomic_open(). | |
925 | * | |
926 | * If the open callback is set to NULL, then the standard f_op->open() | |
927 | * filesystem callback is substituted. | |
0854d450 MS |
928 | * |
929 | * NB: the dentry reference is _not_ consumed. If, for example, the dentry is | |
930 | * the return value of d_splice_alias(), then the caller needs to perform dput() | |
931 | * on it after finish_open(). | |
932 | * | |
0854d450 | 933 | * Returns zero on success or -errno if the open failed. |
d18e9008 | 934 | */ |
30d90494 | 935 | int finish_open(struct file *file, struct dentry *dentry, |
be12af3e | 936 | int (*open)(struct inode *, struct file *)) |
d18e9008 | 937 | { |
aad888f8 | 938 | BUG_ON(file->f_mode & FMODE_OPENED); /* once it's opened, it's opened */ |
d18e9008 | 939 | |
b5bcdda3 | 940 | file->f_path.dentry = dentry; |
aad888f8 | 941 | return do_dentry_open(file, d_backing_inode(dentry), open); |
d18e9008 MS |
942 | } |
943 | EXPORT_SYMBOL(finish_open); | |
944 | ||
945 | /** | |
946 | * finish_no_open - finish ->atomic_open() without opening the file | |
947 | * | |
0854d450 | 948 | * @file: file pointer |
d18e9008 MS |
949 | * @dentry: dentry or NULL (as returned from ->lookup()) |
950 | * | |
951 | * This can be used to set the result of a successful lookup in ->atomic_open(). | |
0854d450 MS |
952 | * |
953 | * NB: unlike finish_open() this function does consume the dentry reference and | |
954 | * the caller need not dput() it. | |
955 | * | |
64e1ac4d | 956 | * Returns "0" which must be the return value of ->atomic_open() after having |
0854d450 | 957 | * called this function. |
d18e9008 | 958 | */ |
e45198a6 | 959 | int finish_no_open(struct file *file, struct dentry *dentry) |
d18e9008 | 960 | { |
30d90494 | 961 | file->f_path.dentry = dentry; |
64e1ac4d | 962 | return 0; |
d18e9008 MS |
963 | } |
964 | EXPORT_SYMBOL(finish_no_open); | |
965 | ||
9bf39ab2 MS |
966 | char *file_path(struct file *filp, char *buf, int buflen) |
967 | { | |
968 | return d_path(&filp->f_path, buf, buflen); | |
969 | } | |
970 | EXPORT_SYMBOL(file_path); | |
971 | ||
4bacc9c9 DH |
972 | /** |
973 | * vfs_open - open the file at the given path | |
974 | * @path: path to open | |
975 | * @file: newly allocated file with f_flag initialized | |
976 | * @cred: credentials to use | |
977 | */ | |
ae2bb293 | 978 | int vfs_open(const struct path *path, struct file *file) |
4bacc9c9 | 979 | { |
54d5ca87 | 980 | file->f_path = *path; |
a6518f73 | 981 | return do_dentry_open(file, d_backing_inode(path->dentry), NULL); |
4bacc9c9 DH |
982 | } |
983 | ||
765927b2 | 984 | struct file *dentry_open(const struct path *path, int flags, |
745ca247 | 985 | const struct cred *cred) |
a1a5b3d9 PS |
986 | { |
987 | int error; | |
988 | struct file *f; | |
989 | ||
e0e81739 DH |
990 | validate_creds(cred); |
991 | ||
c212f9aa | 992 | /* We must always pass in a valid mount pointer. */ |
765927b2 | 993 | BUG_ON(!path->mnt); |
322ee5b3 | 994 | |
ea73ea72 | 995 | f = alloc_empty_file(flags, cred); |
af04fadc | 996 | if (!IS_ERR(f)) { |
ae2bb293 | 997 | error = vfs_open(path, f); |
4d27f326 AV |
998 | if (error) { |
999 | fput(f); | |
af04fadc AV |
1000 | f = ERR_PTR(error); |
1001 | } | |
2a027e7a AV |
1002 | } |
1003 | return f; | |
a1a5b3d9 | 1004 | } |
1da177e4 LT |
1005 | EXPORT_SYMBOL(dentry_open); |
1006 | ||
fb70bf12 CL |
1007 | /** |
1008 | * dentry_create - Create and open a file | |
1009 | * @path: path to create | |
1010 | * @flags: O_ flags | |
1011 | * @mode: mode bits for new file | |
1012 | * @cred: credentials to use | |
1013 | * | |
1014 | * Caller must hold the parent directory's lock, and have prepared | |
1015 | * a negative dentry, placed in @path->dentry, for the new file. | |
1016 | * | |
1017 | * Caller sets @path->mnt to the vfsmount of the filesystem where | |
1018 | * the new file is to be created. The parent directory and the | |
1019 | * negative dentry must reside on the same filesystem instance. | |
1020 | * | |
1021 | * On success, returns a "struct file *". Otherwise a ERR_PTR | |
1022 | * is returned. | |
1023 | */ | |
1024 | struct file *dentry_create(const struct path *path, int flags, umode_t mode, | |
1025 | const struct cred *cred) | |
1026 | { | |
1027 | struct file *f; | |
1028 | int error; | |
1029 | ||
1030 | validate_creds(cred); | |
1031 | f = alloc_empty_file(flags, cred); | |
1032 | if (IS_ERR(f)) | |
1033 | return f; | |
1034 | ||
1035 | error = vfs_create(mnt_user_ns(path->mnt), | |
1036 | d_inode(path->dentry->d_parent), | |
1037 | path->dentry, mode, true); | |
1038 | if (!error) | |
1039 | error = vfs_open(path, f); | |
1040 | ||
1041 | if (unlikely(error)) { | |
1042 | fput(f); | |
1043 | return ERR_PTR(error); | |
1044 | } | |
1045 | return f; | |
1046 | } | |
1047 | EXPORT_SYMBOL(dentry_create); | |
1048 | ||
2abc77af AV |
1049 | struct file *open_with_fake_path(const struct path *path, int flags, |
1050 | struct inode *inode, const struct cred *cred) | |
1051 | { | |
d3b1084d | 1052 | struct file *f = alloc_empty_file_noaccount(flags, cred); |
2abc77af AV |
1053 | if (!IS_ERR(f)) { |
1054 | int error; | |
1055 | ||
1056 | f->f_path = *path; | |
1057 | error = do_dentry_open(f, inode, NULL); | |
1058 | if (error) { | |
1059 | fput(f); | |
1060 | f = ERR_PTR(error); | |
1061 | } | |
1062 | } | |
1063 | return f; | |
1064 | } | |
1065 | EXPORT_SYMBOL(open_with_fake_path); | |
1066 | ||
fddb5d43 AS |
1067 | #define WILL_CREATE(flags) (flags & (O_CREAT | __O_TMPFILE)) |
1068 | #define O_PATH_FLAGS (O_DIRECTORY | O_NOFOLLOW | O_PATH | O_CLOEXEC) | |
1069 | ||
35cb6d54 | 1070 | inline struct open_how build_open_how(int flags, umode_t mode) |
fddb5d43 AS |
1071 | { |
1072 | struct open_how how = { | |
1073 | .flags = flags & VALID_OPEN_FLAGS, | |
1074 | .mode = mode & S_IALLUGO, | |
1075 | }; | |
1076 | ||
1077 | /* O_PATH beats everything else. */ | |
1078 | if (how.flags & O_PATH) | |
1079 | how.flags &= O_PATH_FLAGS; | |
1080 | /* Modes should only be set for create-like flags. */ | |
1081 | if (!WILL_CREATE(how.flags)) | |
1082 | how.mode = 0; | |
1083 | return how; | |
1084 | } | |
1085 | ||
35cb6d54 | 1086 | inline int build_open_flags(const struct open_how *how, struct open_flags *op) |
47c805dc | 1087 | { |
cfe80306 CB |
1088 | u64 flags = how->flags; |
1089 | u64 strip = FMODE_NONOTIFY | O_CLOEXEC; | |
47c805dc | 1090 | int lookup_flags = 0; |
62fb4a15 | 1091 | int acc_mode = ACC_MODE(flags); |
47c805dc | 1092 | |
cfe80306 CB |
1093 | BUILD_BUG_ON_MSG(upper_32_bits(VALID_OPEN_FLAGS), |
1094 | "struct open_flags doesn't yet handle flags > 32 bits"); | |
1095 | ||
1096 | /* | |
1097 | * Strip flags that either shouldn't be set by userspace like | |
1098 | * FMODE_NONOTIFY or that aren't relevant in determining struct | |
1099 | * open_flags like O_CLOEXEC. | |
1100 | */ | |
1101 | flags &= ~strip; | |
fddb5d43 | 1102 | |
629e014b | 1103 | /* |
fddb5d43 AS |
1104 | * Older syscalls implicitly clear all of the invalid flags or argument |
1105 | * values before calling build_open_flags(), but openat2(2) checks all | |
1106 | * of its arguments. | |
629e014b | 1107 | */ |
fddb5d43 AS |
1108 | if (flags & ~VALID_OPEN_FLAGS) |
1109 | return -EINVAL; | |
1110 | if (how->resolve & ~VALID_RESOLVE_FLAGS) | |
1111 | return -EINVAL; | |
629e014b | 1112 | |
398840f8 AS |
1113 | /* Scoping flags are mutually exclusive. */ |
1114 | if ((how->resolve & RESOLVE_BENEATH) && (how->resolve & RESOLVE_IN_ROOT)) | |
1115 | return -EINVAL; | |
1116 | ||
fddb5d43 AS |
1117 | /* Deal with the mode. */ |
1118 | if (WILL_CREATE(flags)) { | |
1119 | if (how->mode & ~S_IALLUGO) | |
1120 | return -EINVAL; | |
1121 | op->mode = how->mode | S_IFREG; | |
1122 | } else { | |
1123 | if (how->mode != 0) | |
1124 | return -EINVAL; | |
e68726ff | 1125 | op->mode = 0; |
fddb5d43 | 1126 | } |
47c805dc AV |
1127 | |
1128 | /* | |
fddb5d43 AS |
1129 | * In order to ensure programs get explicit errors when trying to use |
1130 | * O_TMPFILE on old kernels, O_TMPFILE is implemented such that it | |
1131 | * looks like (O_DIRECTORY|O_RDWR & ~O_CREAT) to old kernels. But we | |
1132 | * have to require userspace to explicitly set it. | |
47c805dc | 1133 | */ |
bb458c64 AV |
1134 | if (flags & __O_TMPFILE) { |
1135 | if ((flags & O_TMPFILE_MASK) != O_TMPFILE) | |
60545d0d | 1136 | return -EINVAL; |
ba57ea64 AV |
1137 | if (!(acc_mode & MAY_WRITE)) |
1138 | return -EINVAL; | |
fddb5d43 AS |
1139 | } |
1140 | if (flags & O_PATH) { | |
1141 | /* O_PATH only permits certain other flags to be set. */ | |
1142 | if (flags & ~O_PATH_FLAGS) | |
1143 | return -EINVAL; | |
1abf0c71 | 1144 | acc_mode = 0; |
1abf0c71 | 1145 | } |
47c805dc | 1146 | |
fddb5d43 AS |
1147 | /* |
1148 | * O_SYNC is implemented as __O_SYNC|O_DSYNC. As many places only | |
1149 | * check for O_DSYNC if the need any syncing at all we enforce it's | |
1150 | * always set instead of having to deal with possibly weird behaviour | |
1151 | * for malicious applications setting only __O_SYNC. | |
1152 | */ | |
1153 | if (flags & __O_SYNC) | |
1154 | flags |= O_DSYNC; | |
1155 | ||
1abf0c71 | 1156 | op->open_flag = flags; |
47c805dc AV |
1157 | |
1158 | /* O_TRUNC implies we need access checks for write permissions */ | |
1159 | if (flags & O_TRUNC) | |
1160 | acc_mode |= MAY_WRITE; | |
1161 | ||
1162 | /* Allow the LSM permission hook to distinguish append | |
1163 | access from general write access. */ | |
1164 | if (flags & O_APPEND) | |
1165 | acc_mode |= MAY_APPEND; | |
1166 | ||
1167 | op->acc_mode = acc_mode; | |
1168 | ||
1abf0c71 AV |
1169 | op->intent = flags & O_PATH ? 0 : LOOKUP_OPEN; |
1170 | ||
47c805dc AV |
1171 | if (flags & O_CREAT) { |
1172 | op->intent |= LOOKUP_CREATE; | |
31d1726d | 1173 | if (flags & O_EXCL) { |
47c805dc | 1174 | op->intent |= LOOKUP_EXCL; |
31d1726d AV |
1175 | flags |= O_NOFOLLOW; |
1176 | } | |
47c805dc AV |
1177 | } |
1178 | ||
1179 | if (flags & O_DIRECTORY) | |
1180 | lookup_flags |= LOOKUP_DIRECTORY; | |
1181 | if (!(flags & O_NOFOLLOW)) | |
1182 | lookup_flags |= LOOKUP_FOLLOW; | |
fddb5d43 AS |
1183 | |
1184 | if (how->resolve & RESOLVE_NO_XDEV) | |
1185 | lookup_flags |= LOOKUP_NO_XDEV; | |
1186 | if (how->resolve & RESOLVE_NO_MAGICLINKS) | |
1187 | lookup_flags |= LOOKUP_NO_MAGICLINKS; | |
1188 | if (how->resolve & RESOLVE_NO_SYMLINKS) | |
1189 | lookup_flags |= LOOKUP_NO_SYMLINKS; | |
1190 | if (how->resolve & RESOLVE_BENEATH) | |
1191 | lookup_flags |= LOOKUP_BENEATH; | |
1192 | if (how->resolve & RESOLVE_IN_ROOT) | |
1193 | lookup_flags |= LOOKUP_IN_ROOT; | |
99668f61 JA |
1194 | if (how->resolve & RESOLVE_CACHED) { |
1195 | /* Don't bother even trying for create/truncate/tmpfile open */ | |
1196 | if (flags & (O_TRUNC | O_CREAT | O_TMPFILE)) | |
1197 | return -EAGAIN; | |
1198 | lookup_flags |= LOOKUP_CACHED; | |
1199 | } | |
fddb5d43 | 1200 | |
f9652e10 AV |
1201 | op->lookup_flags = lookup_flags; |
1202 | return 0; | |
47c805dc AV |
1203 | } |
1204 | ||
669abf4e JL |
1205 | /** |
1206 | * file_open_name - open file and return file pointer | |
1207 | * | |
1208 | * @name: struct filename containing path to open | |
1209 | * @flags: open flags as per the open(2) second argument | |
1210 | * @mode: mode for the new file if O_CREAT is set, else ignored | |
1211 | * | |
1212 | * This is the helper to open a file from kernelspace if you really | |
1213 | * have to. But in generally you should not do this, so please move | |
1214 | * along, nothing to see here.. | |
1215 | */ | |
1216 | struct file *file_open_name(struct filename *name, int flags, umode_t mode) | |
1217 | { | |
1218 | struct open_flags op; | |
fddb5d43 AS |
1219 | struct open_how how = build_open_how(flags, mode); |
1220 | int err = build_open_flags(&how, &op); | |
1221 | if (err) | |
1222 | return ERR_PTR(err); | |
1223 | return do_filp_open(AT_FDCWD, name, &op); | |
669abf4e JL |
1224 | } |
1225 | ||
47c805dc AV |
1226 | /** |
1227 | * filp_open - open file and return file pointer | |
1228 | * | |
1229 | * @filename: path to open | |
1230 | * @flags: open flags as per the open(2) second argument | |
1231 | * @mode: mode for the new file if O_CREAT is set, else ignored | |
1232 | * | |
1233 | * This is the helper to open a file from kernelspace if you really | |
1234 | * have to. But in generally you should not do this, so please move | |
1235 | * along, nothing to see here.. | |
1236 | */ | |
a218d0fd | 1237 | struct file *filp_open(const char *filename, int flags, umode_t mode) |
47c805dc | 1238 | { |
51689104 PM |
1239 | struct filename *name = getname_kernel(filename); |
1240 | struct file *file = ERR_CAST(name); | |
1241 | ||
1242 | if (!IS_ERR(name)) { | |
1243 | file = file_open_name(name, flags, mode); | |
1244 | putname(name); | |
1245 | } | |
1246 | return file; | |
47c805dc AV |
1247 | } |
1248 | EXPORT_SYMBOL(filp_open); | |
1249 | ||
ffb37ca3 | 1250 | struct file *file_open_root(const struct path *root, |
378c6520 | 1251 | const char *filename, int flags, umode_t mode) |
73d049a4 AV |
1252 | { |
1253 | struct open_flags op; | |
fddb5d43 AS |
1254 | struct open_how how = build_open_how(flags, mode); |
1255 | int err = build_open_flags(&how, &op); | |
f9652e10 AV |
1256 | if (err) |
1257 | return ERR_PTR(err); | |
ffb37ca3 | 1258 | return do_file_open_root(root, filename, &op); |
73d049a4 AV |
1259 | } |
1260 | EXPORT_SYMBOL(file_open_root); | |
1261 | ||
fddb5d43 AS |
1262 | static long do_sys_openat2(int dfd, const char __user *filename, |
1263 | struct open_how *how) | |
1da177e4 | 1264 | { |
47c805dc | 1265 | struct open_flags op; |
fddb5d43 | 1266 | int fd = build_open_flags(how, &op); |
f9652e10 AV |
1267 | struct filename *tmp; |
1268 | ||
1269 | if (fd) | |
1270 | return fd; | |
1271 | ||
1272 | tmp = getname(filename); | |
1273 | if (IS_ERR(tmp)) | |
1274 | return PTR_ERR(tmp); | |
1275 | ||
fddb5d43 | 1276 | fd = get_unused_fd_flags(how->flags); |
f9652e10 AV |
1277 | if (fd >= 0) { |
1278 | struct file *f = do_filp_open(dfd, tmp, &op); | |
1279 | if (IS_ERR(f)) { | |
1280 | put_unused_fd(fd); | |
1281 | fd = PTR_ERR(f); | |
1282 | } else { | |
1283 | fsnotify_open(f); | |
1284 | fd_install(fd, f); | |
1da177e4 | 1285 | } |
1da177e4 | 1286 | } |
f9652e10 | 1287 | putname(tmp); |
1da177e4 | 1288 | return fd; |
1da177e4 | 1289 | } |
e922efc3 | 1290 | |
fddb5d43 | 1291 | long do_sys_open(int dfd, const char __user *filename, int flags, umode_t mode) |
e922efc3 | 1292 | { |
fddb5d43 AS |
1293 | struct open_how how = build_open_how(flags, mode); |
1294 | return do_sys_openat2(dfd, filename, &how); | |
1295 | } | |
e922efc3 | 1296 | |
fddb5d43 AS |
1297 | |
1298 | SYSCALL_DEFINE3(open, const char __user *, filename, int, flags, umode_t, mode) | |
1299 | { | |
166e07c3 CH |
1300 | if (force_o_largefile()) |
1301 | flags |= O_LARGEFILE; | |
1302 | return do_sys_open(AT_FDCWD, filename, flags, mode); | |
e922efc3 | 1303 | } |
1da177e4 | 1304 | |
6559eed8 | 1305 | SYSCALL_DEFINE4(openat, int, dfd, const char __user *, filename, int, flags, |
a218d0fd | 1306 | umode_t, mode) |
5590ff0d UD |
1307 | { |
1308 | if (force_o_largefile()) | |
1309 | flags |= O_LARGEFILE; | |
2cf09666 | 1310 | return do_sys_open(dfd, filename, flags, mode); |
5590ff0d | 1311 | } |
5590ff0d | 1312 | |
fddb5d43 AS |
1313 | SYSCALL_DEFINE4(openat2, int, dfd, const char __user *, filename, |
1314 | struct open_how __user *, how, size_t, usize) | |
1315 | { | |
1316 | int err; | |
1317 | struct open_how tmp; | |
1318 | ||
1319 | BUILD_BUG_ON(sizeof(struct open_how) < OPEN_HOW_SIZE_VER0); | |
1320 | BUILD_BUG_ON(sizeof(struct open_how) != OPEN_HOW_SIZE_LATEST); | |
1321 | ||
1322 | if (unlikely(usize < OPEN_HOW_SIZE_VER0)) | |
1323 | return -EINVAL; | |
1324 | ||
1325 | err = copy_struct_from_user(&tmp, sizeof(tmp), how, usize); | |
1326 | if (err) | |
1327 | return err; | |
1328 | ||
571e5c0e RGB |
1329 | audit_openat2_how(&tmp); |
1330 | ||
fddb5d43 AS |
1331 | /* O_LARGEFILE is only allowed for non-O_PATH. */ |
1332 | if (!(tmp.flags & O_PATH) && force_o_largefile()) | |
1333 | tmp.flags |= O_LARGEFILE; | |
1334 | ||
1335 | return do_sys_openat2(dfd, filename, &tmp); | |
1336 | } | |
1337 | ||
e35d49f6 AV |
1338 | #ifdef CONFIG_COMPAT |
1339 | /* | |
1340 | * Exactly like sys_open(), except that it doesn't set the | |
1341 | * O_LARGEFILE flag. | |
1342 | */ | |
1343 | COMPAT_SYSCALL_DEFINE3(open, const char __user *, filename, int, flags, umode_t, mode) | |
1344 | { | |
1345 | return do_sys_open(AT_FDCWD, filename, flags, mode); | |
1346 | } | |
1347 | ||
1348 | /* | |
1349 | * Exactly like sys_openat(), except that it doesn't set the | |
1350 | * O_LARGEFILE flag. | |
1351 | */ | |
1352 | COMPAT_SYSCALL_DEFINE4(openat, int, dfd, const char __user *, filename, int, flags, umode_t, mode) | |
1353 | { | |
1354 | return do_sys_open(dfd, filename, flags, mode); | |
1355 | } | |
1356 | #endif | |
1357 | ||
1da177e4 LT |
1358 | #ifndef __alpha__ |
1359 | ||
1360 | /* | |
1361 | * For backward compatibility? Maybe this should be moved | |
1362 | * into arch/i386 instead? | |
1363 | */ | |
a218d0fd | 1364 | SYSCALL_DEFINE2(creat, const char __user *, pathname, umode_t, mode) |
1da177e4 | 1365 | { |
166e07c3 | 1366 | int flags = O_CREAT | O_WRONLY | O_TRUNC; |
1da177e4 | 1367 | |
166e07c3 CH |
1368 | if (force_o_largefile()) |
1369 | flags |= O_LARGEFILE; | |
1370 | return do_sys_open(AT_FDCWD, pathname, flags, mode); | |
1371 | } | |
1da177e4 LT |
1372 | #endif |
1373 | ||
1374 | /* | |
1375 | * "id" is the POSIX thread ID. We use the | |
1376 | * files pointer for this.. | |
1377 | */ | |
1378 | int filp_close(struct file *filp, fl_owner_t id) | |
1379 | { | |
45778ca8 | 1380 | int retval = 0; |
1da177e4 LT |
1381 | |
1382 | if (!file_count(filp)) { | |
1383 | printk(KERN_ERR "VFS: Close: file count is 0\n"); | |
45778ca8 | 1384 | return 0; |
1da177e4 LT |
1385 | } |
1386 | ||
72c2d531 | 1387 | if (filp->f_op->flush) |
75e1fcc0 | 1388 | retval = filp->f_op->flush(filp, id); |
1da177e4 | 1389 | |
1abf0c71 AV |
1390 | if (likely(!(filp->f_mode & FMODE_PATH))) { |
1391 | dnotify_flush(filp, id); | |
1392 | locks_remove_posix(filp, id); | |
1393 | } | |
1da177e4 LT |
1394 | fput(filp); |
1395 | return retval; | |
1396 | } | |
1397 | ||
1398 | EXPORT_SYMBOL(filp_close); | |
1399 | ||
1400 | /* | |
1401 | * Careful here! We test whether the file pointer is NULL before | |
1402 | * releasing the fd. This ensures that one clone task can't release | |
1403 | * an fd while another clone is opening it. | |
1404 | */ | |
ca013e94 | 1405 | SYSCALL_DEFINE1(close, unsigned int, fd) |
1da177e4 | 1406 | { |
8760c909 | 1407 | int retval = close_fd(fd); |
ee731f4f EP |
1408 | |
1409 | /* can't restart close syscall because file table entry was cleared */ | |
1410 | if (unlikely(retval == -ERESTARTSYS || | |
1411 | retval == -ERESTARTNOINTR || | |
1412 | retval == -ERESTARTNOHAND || | |
1413 | retval == -ERESTART_RESTARTBLOCK)) | |
1414 | retval = -EINTR; | |
1415 | ||
1416 | return retval; | |
1da177e4 | 1417 | } |
1da177e4 | 1418 | |
278a5fba CB |
1419 | /** |
1420 | * close_range() - Close all file descriptors in a given range. | |
1421 | * | |
1422 | * @fd: starting file descriptor to close | |
1423 | * @max_fd: last file descriptor to close | |
1424 | * @flags: reserved for future extensions | |
1425 | * | |
1426 | * This closes a range of file descriptors. All file descriptors | |
1427 | * from @fd up to and including @max_fd are closed. | |
1428 | * Currently, errors to close a given file descriptor are ignored. | |
1429 | */ | |
1430 | SYSCALL_DEFINE3(close_range, unsigned int, fd, unsigned int, max_fd, | |
1431 | unsigned int, flags) | |
1432 | { | |
60997c3d | 1433 | return __close_range(fd, max_fd, flags); |
278a5fba CB |
1434 | } |
1435 | ||
1da177e4 LT |
1436 | /* |
1437 | * This routine simulates a hangup on the tty, to arrange that users | |
1438 | * are given clean terminals at login time. | |
1439 | */ | |
ca013e94 | 1440 | SYSCALL_DEFINE0(vhangup) |
1da177e4 LT |
1441 | { |
1442 | if (capable(CAP_SYS_TTY_CONFIG)) { | |
2cb5998b | 1443 | tty_vhangup_self(); |
1da177e4 LT |
1444 | return 0; |
1445 | } | |
1446 | return -EPERM; | |
1447 | } | |
1448 | ||
1449 | /* | |
1450 | * Called when an inode is about to be open. | |
1451 | * We use this to disallow opening large files on 32bit systems if | |
1452 | * the caller didn't specify O_LARGEFILE. On 64bit systems we force | |
1453 | * on this flag in sys_open. | |
1454 | */ | |
1455 | int generic_file_open(struct inode * inode, struct file * filp) | |
1456 | { | |
1457 | if (!(filp->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS) | |
a9c62a18 | 1458 | return -EOVERFLOW; |
1da177e4 LT |
1459 | return 0; |
1460 | } | |
1461 | ||
1462 | EXPORT_SYMBOL(generic_file_open); | |
1463 | ||
1464 | /* | |
1465 | * This is used by subsystems that don't want seekable | |
06b1e104 DT |
1466 | * file descriptors. The function is not supposed to ever fail, the only |
1467 | * reason it returns an 'int' and not 'void' is so that it can be plugged | |
1468 | * directly into file_operations structure. | |
1da177e4 LT |
1469 | */ |
1470 | int nonseekable_open(struct inode *inode, struct file *filp) | |
1471 | { | |
1472 | filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE); | |
1473 | return 0; | |
1474 | } | |
1475 | ||
1476 | EXPORT_SYMBOL(nonseekable_open); | |
10dce8af KS |
1477 | |
1478 | /* | |
1479 | * stream_open is used by subsystems that want stream-like file descriptors. | |
1480 | * Such file descriptors are not seekable and don't have notion of position | |
438ab720 KS |
1481 | * (file.f_pos is always 0 and ppos passed to .read()/.write() is always NULL). |
1482 | * Contrary to file descriptors of other regular files, .read() and .write() | |
1483 | * can run simultaneously. | |
10dce8af KS |
1484 | * |
1485 | * stream_open never fails and is marked to return int so that it could be | |
1486 | * directly used as file_operations.open . | |
1487 | */ | |
1488 | int stream_open(struct inode *inode, struct file *filp) | |
1489 | { | |
2be7d348 | 1490 | filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE | FMODE_ATOMIC_POS); |
10dce8af KS |
1491 | filp->f_mode |= FMODE_STREAM; |
1492 | return 0; | |
1493 | } | |
1494 | ||
1495 | EXPORT_SYMBOL(stream_open); |