]>
Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/fs/open.c | |
3 | * | |
4 | * Copyright (C) 1991, 1992 Linus Torvalds | |
5 | */ | |
6 | ||
7 | #include <linux/string.h> | |
8 | #include <linux/mm.h> | |
1da177e4 | 9 | #include <linux/file.h> |
9f3acc31 | 10 | #include <linux/fdtable.h> |
0eeca283 | 11 | #include <linux/fsnotify.h> |
1da177e4 | 12 | #include <linux/module.h> |
1da177e4 LT |
13 | #include <linux/tty.h> |
14 | #include <linux/namei.h> | |
15 | #include <linux/backing-dev.h> | |
16f7e0fe | 16 | #include <linux/capability.h> |
086f7316 | 17 | #include <linux/securebits.h> |
1da177e4 LT |
18 | #include <linux/security.h> |
19 | #include <linux/mount.h> | |
5590ff0d | 20 | #include <linux/fcntl.h> |
5a0e3ad6 | 21 | #include <linux/slab.h> |
1da177e4 LT |
22 | #include <asm/uaccess.h> |
23 | #include <linux/fs.h> | |
ef3daeda | 24 | #include <linux/personality.h> |
1da177e4 LT |
25 | #include <linux/pagemap.h> |
26 | #include <linux/syscalls.h> | |
ab2af1f5 | 27 | #include <linux/rcupdate.h> |
73241ccc | 28 | #include <linux/audit.h> |
97ac7350 | 29 | #include <linux/falloc.h> |
5ad4e53b | 30 | #include <linux/fs_struct.h> |
b65a9cfc | 31 | #include <linux/ima.h> |
2dfc1cae | 32 | #include <linux/dnotify.h> |
3f6d078d | 33 | #include <linux/compat.h> |
1da177e4 | 34 | |
e81e3f4d EP |
35 | #include "internal.h" |
36 | ||
4a30131e N |
37 | int do_truncate(struct dentry *dentry, loff_t length, unsigned int time_attrs, |
38 | struct file *filp) | |
1da177e4 | 39 | { |
939a9421 | 40 | int ret; |
1da177e4 LT |
41 | struct iattr newattrs; |
42 | ||
43 | /* Not pretty: "inode->i_size" shouldn't really be signed. But it is. */ | |
44 | if (length < 0) | |
45 | return -EINVAL; | |
46 | ||
47 | newattrs.ia_size = length; | |
4a30131e | 48 | newattrs.ia_valid = ATTR_SIZE | time_attrs; |
cc4e69de MS |
49 | if (filp) { |
50 | newattrs.ia_file = filp; | |
51 | newattrs.ia_valid |= ATTR_FILE; | |
52 | } | |
1da177e4 | 53 | |
45f147a1 JK |
54 | /* Remove suid, sgid, and file capabilities on truncate too */ |
55 | ret = dentry_needs_remove_privs(dentry); | |
56 | if (ret < 0) | |
57 | return ret; | |
939a9421 AW |
58 | if (ret) |
59 | newattrs.ia_valid |= ret | ATTR_FORCE; | |
7b82dc0e | 60 | |
5955102c | 61 | inode_lock(dentry->d_inode); |
27ac0ffe BF |
62 | /* Note any delegations or leases have already been broken: */ |
63 | ret = notify_change(dentry, &newattrs, NULL); | |
5955102c | 64 | inode_unlock(dentry->d_inode); |
939a9421 | 65 | return ret; |
1da177e4 LT |
66 | } |
67 | ||
7df818b2 | 68 | long vfs_truncate(const struct path *path, loff_t length) |
1da177e4 | 69 | { |
2d8f3038 | 70 | struct inode *inode; |
a02de960 | 71 | long error; |
1da177e4 | 72 | |
a02de960 | 73 | inode = path->dentry->d_inode; |
1da177e4 LT |
74 | |
75 | /* For directories it's -EISDIR, for other non-regulars - -EINVAL */ | |
1da177e4 | 76 | if (S_ISDIR(inode->i_mode)) |
a02de960 | 77 | return -EISDIR; |
1da177e4 | 78 | if (!S_ISREG(inode->i_mode)) |
a02de960 | 79 | return -EINVAL; |
1da177e4 | 80 | |
a02de960 | 81 | error = mnt_want_write(path->mnt); |
1da177e4 | 82 | if (error) |
a02de960 | 83 | goto out; |
1da177e4 | 84 | |
256984a8 | 85 | error = inode_permission(inode, MAY_WRITE); |
9ac9b847 DH |
86 | if (error) |
87 | goto mnt_drop_write_and_out; | |
1da177e4 LT |
88 | |
89 | error = -EPERM; | |
c82e42da | 90 | if (IS_APPEND(inode)) |
9ac9b847 | 91 | goto mnt_drop_write_and_out; |
1da177e4 | 92 | |
9700382c | 93 | error = get_write_access(inode); |
1da177e4 | 94 | if (error) |
9ac9b847 | 95 | goto mnt_drop_write_and_out; |
1da177e4 | 96 | |
9700382c | 97 | /* |
98 | * Make sure that there are no leases. get_write_access() protects | |
99 | * against the truncate racing with a lease-granting setlease(). | |
100 | */ | |
8737c930 | 101 | error = break_lease(inode, O_WRONLY); |
1da177e4 | 102 | if (error) |
9700382c | 103 | goto put_write_and_out; |
1da177e4 LT |
104 | |
105 | error = locks_verify_truncate(inode, NULL, length); | |
be6d3e56 | 106 | if (!error) |
a02de960 | 107 | error = security_path_truncate(path); |
907f4554 | 108 | if (!error) |
a02de960 | 109 | error = do_truncate(path->dentry, length, 0, NULL); |
1da177e4 | 110 | |
9700382c | 111 | put_write_and_out: |
112 | put_write_access(inode); | |
9ac9b847 | 113 | mnt_drop_write_and_out: |
a02de960 | 114 | mnt_drop_write(path->mnt); |
1da177e4 LT |
115 | out: |
116 | return error; | |
117 | } | |
a02de960 DH |
118 | EXPORT_SYMBOL_GPL(vfs_truncate); |
119 | ||
120 | static long do_sys_truncate(const char __user *pathname, loff_t length) | |
121 | { | |
48f7530d | 122 | unsigned int lookup_flags = LOOKUP_FOLLOW; |
a02de960 DH |
123 | struct path path; |
124 | int error; | |
125 | ||
126 | if (length < 0) /* sorry, but loff_t says... */ | |
127 | return -EINVAL; | |
128 | ||
48f7530d JL |
129 | retry: |
130 | error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path); | |
a02de960 DH |
131 | if (!error) { |
132 | error = vfs_truncate(&path, length); | |
133 | path_put(&path); | |
134 | } | |
48f7530d JL |
135 | if (retry_estale(error, lookup_flags)) { |
136 | lookup_flags |= LOOKUP_REVAL; | |
137 | goto retry; | |
138 | } | |
a02de960 DH |
139 | return error; |
140 | } | |
1da177e4 | 141 | |
4fd8da8d | 142 | SYSCALL_DEFINE2(truncate, const char __user *, path, long, length) |
1da177e4 | 143 | { |
4fd8da8d | 144 | return do_sys_truncate(path, length); |
1da177e4 LT |
145 | } |
146 | ||
3f6d078d AV |
147 | #ifdef CONFIG_COMPAT |
148 | COMPAT_SYSCALL_DEFINE2(truncate, const char __user *, path, compat_off_t, length) | |
149 | { | |
150 | return do_sys_truncate(path, length); | |
151 | } | |
152 | #endif | |
153 | ||
b01ec0ef | 154 | static long do_sys_ftruncate(unsigned int fd, loff_t length, int small) |
1da177e4 | 155 | { |
bf2965d5 | 156 | struct inode *inode; |
1da177e4 | 157 | struct dentry *dentry; |
2903ff01 | 158 | struct fd f; |
1da177e4 LT |
159 | int error; |
160 | ||
161 | error = -EINVAL; | |
162 | if (length < 0) | |
163 | goto out; | |
164 | error = -EBADF; | |
2903ff01 AV |
165 | f = fdget(fd); |
166 | if (!f.file) | |
1da177e4 LT |
167 | goto out; |
168 | ||
169 | /* explicitly opened as large or we are on 64-bit box */ | |
2903ff01 | 170 | if (f.file->f_flags & O_LARGEFILE) |
1da177e4 LT |
171 | small = 0; |
172 | ||
2903ff01 | 173 | dentry = f.file->f_path.dentry; |
1da177e4 LT |
174 | inode = dentry->d_inode; |
175 | error = -EINVAL; | |
2903ff01 | 176 | if (!S_ISREG(inode->i_mode) || !(f.file->f_mode & FMODE_WRITE)) |
1da177e4 LT |
177 | goto out_putf; |
178 | ||
179 | error = -EINVAL; | |
180 | /* Cannot ftruncate over 2^31 bytes without large file support */ | |
181 | if (small && length > MAX_NON_LFS) | |
182 | goto out_putf; | |
183 | ||
184 | error = -EPERM; | |
185 | if (IS_APPEND(inode)) | |
186 | goto out_putf; | |
187 | ||
14da9200 | 188 | sb_start_write(inode->i_sb); |
2903ff01 | 189 | error = locks_verify_truncate(inode, f.file, length); |
be6d3e56 | 190 | if (!error) |
2903ff01 | 191 | error = security_path_truncate(&f.file->f_path); |
1da177e4 | 192 | if (!error) |
2903ff01 | 193 | error = do_truncate(dentry, length, ATTR_MTIME|ATTR_CTIME, f.file); |
14da9200 | 194 | sb_end_write(inode->i_sb); |
1da177e4 | 195 | out_putf: |
2903ff01 | 196 | fdput(f); |
1da177e4 LT |
197 | out: |
198 | return error; | |
199 | } | |
200 | ||
bdc480e3 | 201 | SYSCALL_DEFINE2(ftruncate, unsigned int, fd, unsigned long, length) |
1da177e4 | 202 | { |
2cf09666 | 203 | return do_sys_ftruncate(fd, length, 1); |
1da177e4 LT |
204 | } |
205 | ||
3f6d078d AV |
206 | #ifdef CONFIG_COMPAT |
207 | COMPAT_SYSCALL_DEFINE2(ftruncate, unsigned int, fd, compat_ulong_t, length) | |
208 | { | |
209 | return do_sys_ftruncate(fd, length, 1); | |
210 | } | |
211 | #endif | |
212 | ||
1da177e4 LT |
213 | /* LFS versions of truncate are only needed on 32 bit machines */ |
214 | #if BITS_PER_LONG == 32 | |
4a0fd5bf | 215 | SYSCALL_DEFINE2(truncate64, const char __user *, path, loff_t, length) |
1da177e4 LT |
216 | { |
217 | return do_sys_truncate(path, length); | |
218 | } | |
219 | ||
4a0fd5bf | 220 | SYSCALL_DEFINE2(ftruncate64, unsigned int, fd, loff_t, length) |
1da177e4 | 221 | { |
2cf09666 | 222 | return do_sys_ftruncate(fd, length, 0); |
1da177e4 | 223 | } |
6673e0c3 | 224 | #endif /* BITS_PER_LONG == 32 */ |
1da177e4 | 225 | |
3e63cbb1 | 226 | |
72c72bdf | 227 | int vfs_fallocate(struct file *file, int mode, loff_t offset, loff_t len) |
97ac7350 | 228 | { |
496ad9aa | 229 | struct inode *inode = file_inode(file); |
3e63cbb1 | 230 | long ret; |
97ac7350 AA |
231 | |
232 | if (offset < 0 || len <= 0) | |
3e63cbb1 | 233 | return -EINVAL; |
97ac7350 AA |
234 | |
235 | /* Return error if mode is not supported */ | |
dd46c787 | 236 | if (mode & ~FALLOC_FL_SUPPORTED_MASK) |
409332b6 LC |
237 | return -EOPNOTSUPP; |
238 | ||
239 | /* Punch hole and zero range are mutually exclusive */ | |
240 | if ((mode & (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_ZERO_RANGE)) == | |
241 | (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_ZERO_RANGE)) | |
79124f18 JB |
242 | return -EOPNOTSUPP; |
243 | ||
244 | /* Punch hole must have keep size set */ | |
245 | if ((mode & FALLOC_FL_PUNCH_HOLE) && | |
246 | !(mode & FALLOC_FL_KEEP_SIZE)) | |
3e63cbb1 | 247 | return -EOPNOTSUPP; |
97ac7350 | 248 | |
00f5e619 NJ |
249 | /* Collapse range should only be used exclusively. */ |
250 | if ((mode & FALLOC_FL_COLLAPSE_RANGE) && | |
251 | (mode & ~FALLOC_FL_COLLAPSE_RANGE)) | |
252 | return -EINVAL; | |
253 | ||
dd46c787 NJ |
254 | /* Insert range should only be used exclusively. */ |
255 | if ((mode & FALLOC_FL_INSERT_RANGE) && | |
256 | (mode & ~FALLOC_FL_INSERT_RANGE)) | |
257 | return -EINVAL; | |
258 | ||
97ac7350 | 259 | if (!(file->f_mode & FMODE_WRITE)) |
3e63cbb1 | 260 | return -EBADF; |
1ca551c6 | 261 | |
00f5e619 | 262 | /* |
8fc61d92 | 263 | * We can only allow pure fallocate on append only files |
00f5e619 | 264 | */ |
8fc61d92 | 265 | if ((mode & ~FALLOC_FL_KEEP_SIZE) && IS_APPEND(inode)) |
1ca551c6 MS |
266 | return -EPERM; |
267 | ||
268 | if (IS_IMMUTABLE(inode)) | |
269 | return -EPERM; | |
270 | ||
0790b31b | 271 | /* |
6d2b6170 | 272 | * We cannot allow any fallocate operation on an active swapfile |
0790b31b LC |
273 | */ |
274 | if (IS_SWAPFILE(inode)) | |
6d2b6170 | 275 | return -ETXTBSY; |
0790b31b | 276 | |
97ac7350 AA |
277 | /* |
278 | * Revalidate the write permissions, in case security policy has | |
279 | * changed since the files were opened. | |
280 | */ | |
281 | ret = security_file_permission(file, MAY_WRITE); | |
282 | if (ret) | |
3e63cbb1 | 283 | return ret; |
97ac7350 | 284 | |
97ac7350 | 285 | if (S_ISFIFO(inode->i_mode)) |
3e63cbb1 | 286 | return -ESPIPE; |
97ac7350 | 287 | |
97ac7350 AA |
288 | /* |
289 | * Let individual file system decide if it supports preallocation | |
290 | * for directories or not. | |
291 | */ | |
292 | if (!S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode)) | |
3e63cbb1 | 293 | return -ENODEV; |
97ac7350 | 294 | |
97ac7350 AA |
295 | /* Check for wrap through zero too */ |
296 | if (((offset + len) > inode->i_sb->s_maxbytes) || ((offset + len) < 0)) | |
3e63cbb1 | 297 | return -EFBIG; |
97ac7350 | 298 | |
2fe17c10 | 299 | if (!file->f_op->fallocate) |
3e63cbb1 | 300 | return -EOPNOTSUPP; |
97ac7350 | 301 | |
14da9200 JK |
302 | sb_start_write(inode->i_sb); |
303 | ret = file->f_op->fallocate(file, mode, offset, len); | |
820c12d5 HS |
304 | |
305 | /* | |
306 | * Create inotify and fanotify events. | |
307 | * | |
308 | * To keep the logic simple always create events if fallocate succeeds. | |
309 | * This implies that events are even created if the file size remains | |
310 | * unchanged, e.g. when using flag FALLOC_FL_KEEP_SIZE. | |
311 | */ | |
312 | if (ret == 0) | |
313 | fsnotify_modify(file); | |
314 | ||
14da9200 JK |
315 | sb_end_write(inode->i_sb); |
316 | return ret; | |
3e63cbb1 | 317 | } |
72c72bdf | 318 | EXPORT_SYMBOL_GPL(vfs_fallocate); |
3e63cbb1 | 319 | |
4a0fd5bf | 320 | SYSCALL_DEFINE4(fallocate, int, fd, int, mode, loff_t, offset, loff_t, len) |
3e63cbb1 | 321 | { |
2903ff01 | 322 | struct fd f = fdget(fd); |
3e63cbb1 AJ |
323 | int error = -EBADF; |
324 | ||
2903ff01 | 325 | if (f.file) { |
72c72bdf | 326 | error = vfs_fallocate(f.file, mode, offset, len); |
2903ff01 | 327 | fdput(f); |
3e63cbb1 | 328 | } |
3e63cbb1 | 329 | return error; |
97ac7350 | 330 | } |
3e63cbb1 | 331 | |
1da177e4 LT |
332 | /* |
333 | * access() needs to use the real uid/gid, not the effective uid/gid. | |
334 | * We do this by temporarily clearing all FS-related capabilities and | |
335 | * switching the fsuid/fsgid around to the real ones. | |
336 | */ | |
6559eed8 | 337 | SYSCALL_DEFINE3(faccessat, int, dfd, const char __user *, filename, int, mode) |
1da177e4 | 338 | { |
d84f4f99 DH |
339 | const struct cred *old_cred; |
340 | struct cred *override_cred; | |
2d8f3038 | 341 | struct path path; |
256984a8 | 342 | struct inode *inode; |
1da177e4 | 343 | int res; |
87fa5595 | 344 | unsigned int lookup_flags = LOOKUP_FOLLOW; |
1da177e4 LT |
345 | |
346 | if (mode & ~S_IRWXO) /* where's F_OK, X_OK, W_OK, R_OK? */ | |
347 | return -EINVAL; | |
348 | ||
d84f4f99 DH |
349 | override_cred = prepare_creds(); |
350 | if (!override_cred) | |
351 | return -ENOMEM; | |
1da177e4 | 352 | |
d84f4f99 DH |
353 | override_cred->fsuid = override_cred->uid; |
354 | override_cred->fsgid = override_cred->gid; | |
1da177e4 | 355 | |
086f7316 | 356 | if (!issecure(SECURE_NO_SETUID_FIXUP)) { |
1cdcbec1 | 357 | /* Clear the capabilities if we switch to a non-root user */ |
18815a18 EB |
358 | kuid_t root_uid = make_kuid(override_cred->user_ns, 0); |
359 | if (!uid_eq(override_cred->uid, root_uid)) | |
d84f4f99 | 360 | cap_clear(override_cred->cap_effective); |
086f7316 | 361 | else |
d84f4f99 DH |
362 | override_cred->cap_effective = |
363 | override_cred->cap_permitted; | |
086f7316 | 364 | } |
1da177e4 | 365 | |
d84f4f99 | 366 | old_cred = override_creds(override_cred); |
87fa5595 JL |
367 | retry: |
368 | res = user_path_at(dfd, filename, lookup_flags, &path); | |
6902d925 DH |
369 | if (res) |
370 | goto out; | |
371 | ||
63afdfc7 | 372 | inode = d_backing_inode(path.dentry); |
256984a8 AV |
373 | |
374 | if ((mode & MAY_EXEC) && S_ISREG(inode->i_mode)) { | |
30524472 AV |
375 | /* |
376 | * MAY_EXEC on regular files is denied if the fs is mounted | |
377 | * with the "noexec" flag. | |
378 | */ | |
379 | res = -EACCES; | |
90f8572b | 380 | if (path_noexec(&path)) |
30524472 AV |
381 | goto out_path_release; |
382 | } | |
383 | ||
256984a8 | 384 | res = inode_permission(inode, mode | MAY_ACCESS); |
6902d925 | 385 | /* SuS v2 requires we report a read only fs too */ |
256984a8 | 386 | if (res || !(mode & S_IWOTH) || special_file(inode->i_mode)) |
6902d925 | 387 | goto out_path_release; |
2f676cbc DH |
388 | /* |
389 | * This is a rare case where using __mnt_is_readonly() | |
390 | * is OK without a mnt_want/drop_write() pair. Since | |
391 | * no actual write to the fs is performed here, we do | |
392 | * not need to telegraph to that to anyone. | |
393 | * | |
394 | * By doing this, we accept that this access is | |
395 | * inherently racy and know that the fs may change | |
396 | * state before we even see this result. | |
397 | */ | |
2d8f3038 | 398 | if (__mnt_is_readonly(path.mnt)) |
6902d925 | 399 | res = -EROFS; |
1da177e4 | 400 | |
6902d925 | 401 | out_path_release: |
2d8f3038 | 402 | path_put(&path); |
87fa5595 JL |
403 | if (retry_estale(res, lookup_flags)) { |
404 | lookup_flags |= LOOKUP_REVAL; | |
405 | goto retry; | |
406 | } | |
6902d925 | 407 | out: |
d84f4f99 DH |
408 | revert_creds(old_cred); |
409 | put_cred(override_cred); | |
1da177e4 LT |
410 | return res; |
411 | } | |
412 | ||
ca013e94 | 413 | SYSCALL_DEFINE2(access, const char __user *, filename, int, mode) |
5590ff0d UD |
414 | { |
415 | return sys_faccessat(AT_FDCWD, filename, mode); | |
416 | } | |
417 | ||
3cdad428 | 418 | SYSCALL_DEFINE1(chdir, const char __user *, filename) |
1da177e4 | 419 | { |
2d8f3038 | 420 | struct path path; |
1da177e4 | 421 | int error; |
0291c0a5 JL |
422 | unsigned int lookup_flags = LOOKUP_FOLLOW | LOOKUP_DIRECTORY; |
423 | retry: | |
424 | error = user_path_at(AT_FDCWD, filename, lookup_flags, &path); | |
1da177e4 LT |
425 | if (error) |
426 | goto out; | |
427 | ||
9cfcac81 | 428 | error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_CHDIR); |
1da177e4 LT |
429 | if (error) |
430 | goto dput_and_out; | |
431 | ||
2d8f3038 | 432 | set_fs_pwd(current->fs, &path); |
1da177e4 LT |
433 | |
434 | dput_and_out: | |
2d8f3038 | 435 | path_put(&path); |
0291c0a5 JL |
436 | if (retry_estale(error, lookup_flags)) { |
437 | lookup_flags |= LOOKUP_REVAL; | |
438 | goto retry; | |
439 | } | |
1da177e4 LT |
440 | out: |
441 | return error; | |
442 | } | |
443 | ||
3cdad428 | 444 | SYSCALL_DEFINE1(fchdir, unsigned int, fd) |
1da177e4 | 445 | { |
2903ff01 | 446 | struct fd f = fdget_raw(fd); |
1da177e4 | 447 | struct inode *inode; |
2903ff01 | 448 | int error = -EBADF; |
1da177e4 LT |
449 | |
450 | error = -EBADF; | |
2903ff01 | 451 | if (!f.file) |
1da177e4 LT |
452 | goto out; |
453 | ||
496ad9aa | 454 | inode = file_inode(f.file); |
1da177e4 LT |
455 | |
456 | error = -ENOTDIR; | |
457 | if (!S_ISDIR(inode->i_mode)) | |
458 | goto out_putf; | |
459 | ||
9cfcac81 | 460 | error = inode_permission(inode, MAY_EXEC | MAY_CHDIR); |
1da177e4 | 461 | if (!error) |
2903ff01 | 462 | set_fs_pwd(current->fs, &f.file->f_path); |
1da177e4 | 463 | out_putf: |
2903ff01 | 464 | fdput(f); |
1da177e4 LT |
465 | out: |
466 | return error; | |
467 | } | |
468 | ||
3480b257 | 469 | SYSCALL_DEFINE1(chroot, const char __user *, filename) |
1da177e4 | 470 | { |
2d8f3038 | 471 | struct path path; |
1da177e4 | 472 | int error; |
2771261e JL |
473 | unsigned int lookup_flags = LOOKUP_FOLLOW | LOOKUP_DIRECTORY; |
474 | retry: | |
475 | error = user_path_at(AT_FDCWD, filename, lookup_flags, &path); | |
1da177e4 LT |
476 | if (error) |
477 | goto out; | |
478 | ||
9cfcac81 | 479 | error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_CHDIR); |
1da177e4 LT |
480 | if (error) |
481 | goto dput_and_out; | |
482 | ||
483 | error = -EPERM; | |
c7b96acf | 484 | if (!ns_capable(current_user_ns(), CAP_SYS_CHROOT)) |
1da177e4 | 485 | goto dput_and_out; |
8b8efb44 TH |
486 | error = security_path_chroot(&path); |
487 | if (error) | |
488 | goto dput_and_out; | |
1da177e4 | 489 | |
2d8f3038 | 490 | set_fs_root(current->fs, &path); |
1da177e4 LT |
491 | error = 0; |
492 | dput_and_out: | |
2d8f3038 | 493 | path_put(&path); |
2771261e JL |
494 | if (retry_estale(error, lookup_flags)) { |
495 | lookup_flags |= LOOKUP_REVAL; | |
496 | goto retry; | |
497 | } | |
1da177e4 LT |
498 | out: |
499 | return error; | |
500 | } | |
501 | ||
be01f9f2 | 502 | static int chmod_common(const struct path *path, umode_t mode) |
1da177e4 | 503 | { |
e57712eb | 504 | struct inode *inode = path->dentry->d_inode; |
27ac0ffe | 505 | struct inode *delegated_inode = NULL; |
1da177e4 | 506 | struct iattr newattrs; |
e57712eb | 507 | int error; |
1da177e4 | 508 | |
e57712eb AV |
509 | error = mnt_want_write(path->mnt); |
510 | if (error) | |
511 | return error; | |
27ac0ffe | 512 | retry_deleg: |
5955102c | 513 | inode_lock(inode); |
cdcf116d | 514 | error = security_path_chmod(path, mode); |
e57712eb | 515 | if (error) |
fe542cf5 | 516 | goto out_unlock; |
1da177e4 LT |
517 | newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO); |
518 | newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; | |
27ac0ffe | 519 | error = notify_change(path->dentry, &newattrs, &delegated_inode); |
fe542cf5 | 520 | out_unlock: |
5955102c | 521 | inode_unlock(inode); |
27ac0ffe BF |
522 | if (delegated_inode) { |
523 | error = break_deleg_wait(&delegated_inode); | |
524 | if (!error) | |
525 | goto retry_deleg; | |
526 | } | |
e57712eb AV |
527 | mnt_drop_write(path->mnt); |
528 | return error; | |
529 | } | |
530 | ||
49f0a076 | 531 | SYSCALL_DEFINE2(fchmod, unsigned int, fd, umode_t, mode) |
e57712eb | 532 | { |
173c8401 | 533 | struct fd f = fdget(fd); |
e57712eb AV |
534 | int err = -EBADF; |
535 | ||
173c8401 | 536 | if (f.file) { |
9f45f5bf | 537 | audit_file(f.file); |
173c8401 AV |
538 | err = chmod_common(&f.file->f_path, mode); |
539 | fdput(f); | |
e57712eb | 540 | } |
1da177e4 LT |
541 | return err; |
542 | } | |
543 | ||
49f0a076 | 544 | SYSCALL_DEFINE3(fchmodat, int, dfd, const char __user *, filename, umode_t, mode) |
1da177e4 | 545 | { |
2d8f3038 | 546 | struct path path; |
1da177e4 | 547 | int error; |
14ff690c JL |
548 | unsigned int lookup_flags = LOOKUP_FOLLOW; |
549 | retry: | |
550 | error = user_path_at(dfd, filename, lookup_flags, &path); | |
e57712eb AV |
551 | if (!error) { |
552 | error = chmod_common(&path, mode); | |
553 | path_put(&path); | |
14ff690c JL |
554 | if (retry_estale(error, lookup_flags)) { |
555 | lookup_flags |= LOOKUP_REVAL; | |
556 | goto retry; | |
557 | } | |
e57712eb | 558 | } |
1da177e4 LT |
559 | return error; |
560 | } | |
561 | ||
49f0a076 | 562 | SYSCALL_DEFINE2(chmod, const char __user *, filename, umode_t, mode) |
5590ff0d UD |
563 | { |
564 | return sys_fchmodat(AT_FDCWD, filename, mode); | |
565 | } | |
566 | ||
7fd25dac | 567 | static int chown_common(const struct path *path, uid_t user, gid_t group) |
1da177e4 | 568 | { |
fe542cf5 | 569 | struct inode *inode = path->dentry->d_inode; |
27ac0ffe | 570 | struct inode *delegated_inode = NULL; |
1da177e4 LT |
571 | int error; |
572 | struct iattr newattrs; | |
52137abe EB |
573 | kuid_t uid; |
574 | kgid_t gid; | |
575 | ||
576 | uid = make_kuid(current_user_ns(), user); | |
577 | gid = make_kgid(current_user_ns(), group); | |
1da177e4 | 578 | |
c1b8940b | 579 | retry_deleg: |
1da177e4 LT |
580 | newattrs.ia_valid = ATTR_CTIME; |
581 | if (user != (uid_t) -1) { | |
52137abe EB |
582 | if (!uid_valid(uid)) |
583 | return -EINVAL; | |
1da177e4 | 584 | newattrs.ia_valid |= ATTR_UID; |
52137abe | 585 | newattrs.ia_uid = uid; |
1da177e4 LT |
586 | } |
587 | if (group != (gid_t) -1) { | |
52137abe EB |
588 | if (!gid_valid(gid)) |
589 | return -EINVAL; | |
1da177e4 | 590 | newattrs.ia_valid |= ATTR_GID; |
52137abe | 591 | newattrs.ia_gid = gid; |
1da177e4 LT |
592 | } |
593 | if (!S_ISDIR(inode->i_mode)) | |
b5376771 SH |
594 | newattrs.ia_valid |= |
595 | ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV; | |
5955102c | 596 | inode_lock(inode); |
d2b31ca6 | 597 | error = security_path_chown(path, uid, gid); |
fe542cf5 | 598 | if (!error) |
27ac0ffe | 599 | error = notify_change(path->dentry, &newattrs, &delegated_inode); |
5955102c | 600 | inode_unlock(inode); |
27ac0ffe BF |
601 | if (delegated_inode) { |
602 | error = break_deleg_wait(&delegated_inode); | |
603 | if (!error) | |
604 | goto retry_deleg; | |
605 | } | |
1da177e4 LT |
606 | return error; |
607 | } | |
608 | ||
6559eed8 HC |
609 | SYSCALL_DEFINE5(fchownat, int, dfd, const char __user *, filename, uid_t, user, |
610 | gid_t, group, int, flag) | |
5590ff0d | 611 | { |
2d8f3038 | 612 | struct path path; |
5590ff0d | 613 | int error = -EINVAL; |
65cfc672 | 614 | int lookup_flags; |
5590ff0d | 615 | |
65cfc672 | 616 | if ((flag & ~(AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH)) != 0) |
5590ff0d UD |
617 | goto out; |
618 | ||
65cfc672 AV |
619 | lookup_flags = (flag & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW; |
620 | if (flag & AT_EMPTY_PATH) | |
621 | lookup_flags |= LOOKUP_EMPTY; | |
99a5df37 | 622 | retry: |
65cfc672 | 623 | error = user_path_at(dfd, filename, lookup_flags, &path); |
6902d925 DH |
624 | if (error) |
625 | goto out; | |
2d8f3038 | 626 | error = mnt_want_write(path.mnt); |
2af482a7 DH |
627 | if (error) |
628 | goto out_release; | |
fe542cf5 | 629 | error = chown_common(&path, user, group); |
2d8f3038 | 630 | mnt_drop_write(path.mnt); |
2af482a7 | 631 | out_release: |
2d8f3038 | 632 | path_put(&path); |
99a5df37 JL |
633 | if (retry_estale(error, lookup_flags)) { |
634 | lookup_flags |= LOOKUP_REVAL; | |
635 | goto retry; | |
636 | } | |
5590ff0d UD |
637 | out: |
638 | return error; | |
639 | } | |
640 | ||
55e4def0 | 641 | SYSCALL_DEFINE3(chown, const char __user *, filename, uid_t, user, gid_t, group) |
1da177e4 | 642 | { |
55e4def0 DH |
643 | return sys_fchownat(AT_FDCWD, filename, user, group, 0); |
644 | } | |
1da177e4 | 645 | |
55e4def0 DH |
646 | SYSCALL_DEFINE3(lchown, const char __user *, filename, uid_t, user, gid_t, group) |
647 | { | |
648 | return sys_fchownat(AT_FDCWD, filename, user, group, | |
649 | AT_SYMLINK_NOFOLLOW); | |
1da177e4 LT |
650 | } |
651 | ||
ca013e94 | 652 | SYSCALL_DEFINE3(fchown, unsigned int, fd, uid_t, user, gid_t, group) |
1da177e4 | 653 | { |
2903ff01 | 654 | struct fd f = fdget(fd); |
1da177e4 LT |
655 | int error = -EBADF; |
656 | ||
2903ff01 | 657 | if (!f.file) |
6902d925 DH |
658 | goto out; |
659 | ||
2903ff01 | 660 | error = mnt_want_write_file(f.file); |
2af482a7 DH |
661 | if (error) |
662 | goto out_fput; | |
9f45f5bf | 663 | audit_file(f.file); |
2903ff01 AV |
664 | error = chown_common(&f.file->f_path, user, group); |
665 | mnt_drop_write_file(f.file); | |
2af482a7 | 666 | out_fput: |
2903ff01 | 667 | fdput(f); |
6902d925 | 668 | out: |
1da177e4 LT |
669 | return error; |
670 | } | |
671 | ||
90ad1a8e MS |
672 | int open_check_o_direct(struct file *f) |
673 | { | |
674 | /* NB: we're sure to have correct a_ops only after f_op->open */ | |
675 | if (f->f_flags & O_DIRECT) { | |
e748dcd0 | 676 | if (!f->f_mapping->a_ops || !f->f_mapping->a_ops->direct_IO) |
90ad1a8e | 677 | return -EINVAL; |
90ad1a8e MS |
678 | } |
679 | return 0; | |
680 | } | |
681 | ||
02e5180d | 682 | static int do_dentry_open(struct file *f, |
4bacc9c9 | 683 | struct inode *inode, |
96b7e579 AV |
684 | int (*open)(struct inode *, struct file *), |
685 | const struct cred *cred) | |
1da177e4 | 686 | { |
1abf0c71 | 687 | static const struct file_operations empty_fops = {}; |
1da177e4 LT |
688 | int error; |
689 | ||
5300990c | 690 | f->f_mode = OPEN_FMODE(f->f_flags) | FMODE_LSEEK | |
a1a5b3d9 | 691 | FMODE_PREAD | FMODE_PWRITE; |
1abf0c71 | 692 | |
b5bcdda3 | 693 | path_get(&f->f_path); |
4bacc9c9 | 694 | f->f_inode = inode; |
1da177e4 | 695 | f->f_mapping = inode->i_mapping; |
1da177e4 | 696 | |
3f4d5a00 AV |
697 | if (unlikely(f->f_flags & O_PATH)) { |
698 | f->f_mode = FMODE_PATH; | |
1abf0c71 | 699 | f->f_op = &empty_fops; |
96b7e579 | 700 | return 0; |
1abf0c71 AV |
701 | } |
702 | ||
dd20908a | 703 | if (f->f_mode & FMODE_WRITE && !special_file(inode->i_mode)) { |
0ccb2863 | 704 | error = get_write_access(inode); |
3f4d5a00 | 705 | if (unlikely(error)) |
1da177e4 | 706 | goto cleanup_file; |
0ccb2863 | 707 | error = __mnt_want_write(f->f_path.mnt); |
3f4d5a00 | 708 | if (unlikely(error)) { |
0ccb2863 AV |
709 | put_write_access(inode); |
710 | goto cleanup_file; | |
711 | } | |
83f936c7 | 712 | f->f_mode |= FMODE_WRITER; |
1da177e4 LT |
713 | } |
714 | ||
9c225f26 | 715 | /* POSIX.1-2008/SUSv4 Section XSI 2.9.7 */ |
63b6df14 | 716 | if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)) |
9c225f26 LT |
717 | f->f_mode |= FMODE_ATOMIC_POS; |
718 | ||
1abf0c71 | 719 | f->f_op = fops_get(inode->i_fop); |
72c2d531 AV |
720 | if (unlikely(WARN_ON(!f->f_op))) { |
721 | error = -ENODEV; | |
722 | goto cleanup_all; | |
723 | } | |
1abf0c71 | 724 | |
83d49856 | 725 | error = security_file_open(f, cred); |
788e7dd4 YN |
726 | if (error) |
727 | goto cleanup_all; | |
728 | ||
f3c7691e BF |
729 | error = break_lease(inode, f->f_flags); |
730 | if (error) | |
731 | goto cleanup_all; | |
732 | ||
72c2d531 | 733 | if (!open) |
834f2a4a TM |
734 | open = f->f_op->open; |
735 | if (open) { | |
736 | error = open(inode, f); | |
1da177e4 LT |
737 | if (error) |
738 | goto cleanup_all; | |
739 | } | |
890275b5 MZ |
740 | if ((f->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ) |
741 | i_readcount_inc(inode); | |
293bc982 | 742 | if ((f->f_mode & FMODE_READ) && |
84363182 | 743 | likely(f->f_op->read || f->f_op->read_iter)) |
7f7f25e8 | 744 | f->f_mode |= FMODE_CAN_READ; |
293bc982 | 745 | if ((f->f_mode & FMODE_WRITE) && |
84363182 | 746 | likely(f->f_op->write || f->f_op->write_iter)) |
7f7f25e8 | 747 | f->f_mode |= FMODE_CAN_WRITE; |
834f2a4a | 748 | |
1da177e4 LT |
749 | f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC); |
750 | ||
751 | file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping); | |
752 | ||
96b7e579 | 753 | return 0; |
1da177e4 LT |
754 | |
755 | cleanup_all: | |
756 | fops_put(f->f_op); | |
83f936c7 | 757 | if (f->f_mode & FMODE_WRITER) { |
1da177e4 | 758 | put_write_access(inode); |
83f936c7 | 759 | __mnt_drop_write(f->f_path.mnt); |
4a3fd211 | 760 | } |
1da177e4 | 761 | cleanup_file: |
02e5180d AV |
762 | path_put(&f->f_path); |
763 | f->f_path.mnt = NULL; | |
764 | f->f_path.dentry = NULL; | |
dd37978c | 765 | f->f_inode = NULL; |
96b7e579 | 766 | return error; |
1da177e4 LT |
767 | } |
768 | ||
d18e9008 MS |
769 | /** |
770 | * finish_open - finish opening a file | |
0854d450 | 771 | * @file: file pointer |
d18e9008 MS |
772 | * @dentry: pointer to dentry |
773 | * @open: open callback | |
0854d450 | 774 | * @opened: state of open |
d18e9008 MS |
775 | * |
776 | * This can be used to finish opening a file passed to i_op->atomic_open(). | |
777 | * | |
778 | * If the open callback is set to NULL, then the standard f_op->open() | |
779 | * filesystem callback is substituted. | |
0854d450 MS |
780 | * |
781 | * NB: the dentry reference is _not_ consumed. If, for example, the dentry is | |
782 | * the return value of d_splice_alias(), then the caller needs to perform dput() | |
783 | * on it after finish_open(). | |
784 | * | |
785 | * On successful return @file is a fully instantiated open file. After this, if | |
786 | * an error occurs in ->atomic_open(), it needs to clean up with fput(). | |
787 | * | |
788 | * Returns zero on success or -errno if the open failed. | |
d18e9008 | 789 | */ |
30d90494 AV |
790 | int finish_open(struct file *file, struct dentry *dentry, |
791 | int (*open)(struct inode *, struct file *), | |
792 | int *opened) | |
d18e9008 | 793 | { |
96b7e579 | 794 | int error; |
3d8a00d2 | 795 | BUG_ON(*opened & FILE_OPENED); /* once it's opened, it's opened */ |
d18e9008 | 796 | |
b5bcdda3 | 797 | file->f_path.dentry = dentry; |
4bacc9c9 DH |
798 | error = do_dentry_open(file, d_backing_inode(dentry), open, |
799 | current_cred()); | |
96b7e579 | 800 | if (!error) |
47237687 | 801 | *opened |= FILE_OPENED; |
d18e9008 | 802 | |
96b7e579 | 803 | return error; |
d18e9008 MS |
804 | } |
805 | EXPORT_SYMBOL(finish_open); | |
806 | ||
807 | /** | |
808 | * finish_no_open - finish ->atomic_open() without opening the file | |
809 | * | |
0854d450 | 810 | * @file: file pointer |
d18e9008 MS |
811 | * @dentry: dentry or NULL (as returned from ->lookup()) |
812 | * | |
813 | * This can be used to set the result of a successful lookup in ->atomic_open(). | |
0854d450 MS |
814 | * |
815 | * NB: unlike finish_open() this function does consume the dentry reference and | |
816 | * the caller need not dput() it. | |
817 | * | |
818 | * Returns "1" which must be the return value of ->atomic_open() after having | |
819 | * called this function. | |
d18e9008 | 820 | */ |
e45198a6 | 821 | int finish_no_open(struct file *file, struct dentry *dentry) |
d18e9008 | 822 | { |
30d90494 | 823 | file->f_path.dentry = dentry; |
e45198a6 | 824 | return 1; |
d18e9008 MS |
825 | } |
826 | EXPORT_SYMBOL(finish_no_open); | |
827 | ||
9bf39ab2 MS |
828 | char *file_path(struct file *filp, char *buf, int buflen) |
829 | { | |
830 | return d_path(&filp->f_path, buf, buflen); | |
831 | } | |
832 | EXPORT_SYMBOL(file_path); | |
833 | ||
4bacc9c9 DH |
834 | /** |
835 | * vfs_open - open the file at the given path | |
836 | * @path: path to open | |
837 | * @file: newly allocated file with f_flag initialized | |
838 | * @cred: credentials to use | |
839 | */ | |
840 | int vfs_open(const struct path *path, struct file *file, | |
841 | const struct cred *cred) | |
842 | { | |
2d902671 | 843 | struct dentry *dentry = d_real(path->dentry, NULL, file->f_flags); |
4bacc9c9 | 844 | |
2d902671 MS |
845 | if (IS_ERR(dentry)) |
846 | return PTR_ERR(dentry); | |
4bacc9c9 | 847 | |
54d5ca87 | 848 | file->f_path = *path; |
2d902671 | 849 | return do_dentry_open(file, d_backing_inode(dentry), NULL, cred); |
4bacc9c9 DH |
850 | } |
851 | ||
765927b2 | 852 | struct file *dentry_open(const struct path *path, int flags, |
745ca247 | 853 | const struct cred *cred) |
a1a5b3d9 PS |
854 | { |
855 | int error; | |
856 | struct file *f; | |
857 | ||
e0e81739 DH |
858 | validate_creds(cred); |
859 | ||
c212f9aa | 860 | /* We must always pass in a valid mount pointer. */ |
765927b2 | 861 | BUG_ON(!path->mnt); |
322ee5b3 | 862 | |
a1a5b3d9 | 863 | f = get_empty_filp(); |
1afc99be AV |
864 | if (!IS_ERR(f)) { |
865 | f->f_flags = flags; | |
4aa7c634 | 866 | error = vfs_open(path, f, cred); |
1afc99be AV |
867 | if (!error) { |
868 | /* from now on we need fput() to dispose of f */ | |
869 | error = open_check_o_direct(f); | |
870 | if (error) { | |
871 | fput(f); | |
872 | f = ERR_PTR(error); | |
873 | } | |
874 | } else { | |
875 | put_filp(f); | |
2a027e7a AV |
876 | f = ERR_PTR(error); |
877 | } | |
2a027e7a AV |
878 | } |
879 | return f; | |
a1a5b3d9 | 880 | } |
1da177e4 LT |
881 | EXPORT_SYMBOL(dentry_open); |
882 | ||
a218d0fd | 883 | static inline int build_open_flags(int flags, umode_t mode, struct open_flags *op) |
47c805dc AV |
884 | { |
885 | int lookup_flags = 0; | |
62fb4a15 | 886 | int acc_mode = ACC_MODE(flags); |
47c805dc | 887 | |
e305f48b | 888 | if (flags & (O_CREAT | __O_TMPFILE)) |
e68726ff MS |
889 | op->mode = (mode & S_IALLUGO) | S_IFREG; |
890 | else | |
891 | op->mode = 0; | |
47c805dc AV |
892 | |
893 | /* Must never be set by userspace */ | |
c6f3d811 | 894 | flags &= ~FMODE_NONOTIFY & ~O_CLOEXEC; |
47c805dc AV |
895 | |
896 | /* | |
897 | * O_SYNC is implemented as __O_SYNC|O_DSYNC. As many places only | |
898 | * check for O_DSYNC if the need any syncing at all we enforce it's | |
899 | * always set instead of having to deal with possibly weird behaviour | |
900 | * for malicious applications setting only __O_SYNC. | |
901 | */ | |
902 | if (flags & __O_SYNC) | |
903 | flags |= O_DSYNC; | |
904 | ||
bb458c64 AV |
905 | if (flags & __O_TMPFILE) { |
906 | if ((flags & O_TMPFILE_MASK) != O_TMPFILE) | |
60545d0d | 907 | return -EINVAL; |
ba57ea64 AV |
908 | if (!(acc_mode & MAY_WRITE)) |
909 | return -EINVAL; | |
60545d0d AV |
910 | } else if (flags & O_PATH) { |
911 | /* | |
912 | * If we have O_PATH in the open flag. Then we | |
913 | * cannot have anything other than the below set of flags | |
914 | */ | |
1abf0c71 AV |
915 | flags &= O_DIRECTORY | O_NOFOLLOW | O_PATH; |
916 | acc_mode = 0; | |
1abf0c71 | 917 | } |
47c805dc | 918 | |
1abf0c71 | 919 | op->open_flag = flags; |
47c805dc AV |
920 | |
921 | /* O_TRUNC implies we need access checks for write permissions */ | |
922 | if (flags & O_TRUNC) | |
923 | acc_mode |= MAY_WRITE; | |
924 | ||
925 | /* Allow the LSM permission hook to distinguish append | |
926 | access from general write access. */ | |
927 | if (flags & O_APPEND) | |
928 | acc_mode |= MAY_APPEND; | |
929 | ||
930 | op->acc_mode = acc_mode; | |
931 | ||
1abf0c71 AV |
932 | op->intent = flags & O_PATH ? 0 : LOOKUP_OPEN; |
933 | ||
47c805dc AV |
934 | if (flags & O_CREAT) { |
935 | op->intent |= LOOKUP_CREATE; | |
936 | if (flags & O_EXCL) | |
937 | op->intent |= LOOKUP_EXCL; | |
938 | } | |
939 | ||
940 | if (flags & O_DIRECTORY) | |
941 | lookup_flags |= LOOKUP_DIRECTORY; | |
942 | if (!(flags & O_NOFOLLOW)) | |
943 | lookup_flags |= LOOKUP_FOLLOW; | |
f9652e10 AV |
944 | op->lookup_flags = lookup_flags; |
945 | return 0; | |
47c805dc AV |
946 | } |
947 | ||
669abf4e JL |
948 | /** |
949 | * file_open_name - open file and return file pointer | |
950 | * | |
951 | * @name: struct filename containing path to open | |
952 | * @flags: open flags as per the open(2) second argument | |
953 | * @mode: mode for the new file if O_CREAT is set, else ignored | |
954 | * | |
955 | * This is the helper to open a file from kernelspace if you really | |
956 | * have to. But in generally you should not do this, so please move | |
957 | * along, nothing to see here.. | |
958 | */ | |
959 | struct file *file_open_name(struct filename *name, int flags, umode_t mode) | |
960 | { | |
961 | struct open_flags op; | |
f9652e10 AV |
962 | int err = build_open_flags(flags, mode, &op); |
963 | return err ? ERR_PTR(err) : do_filp_open(AT_FDCWD, name, &op); | |
669abf4e JL |
964 | } |
965 | ||
47c805dc AV |
966 | /** |
967 | * filp_open - open file and return file pointer | |
968 | * | |
969 | * @filename: path to open | |
970 | * @flags: open flags as per the open(2) second argument | |
971 | * @mode: mode for the new file if O_CREAT is set, else ignored | |
972 | * | |
973 | * This is the helper to open a file from kernelspace if you really | |
974 | * have to. But in generally you should not do this, so please move | |
975 | * along, nothing to see here.. | |
976 | */ | |
a218d0fd | 977 | struct file *filp_open(const char *filename, int flags, umode_t mode) |
47c805dc | 978 | { |
51689104 PM |
979 | struct filename *name = getname_kernel(filename); |
980 | struct file *file = ERR_CAST(name); | |
981 | ||
982 | if (!IS_ERR(name)) { | |
983 | file = file_open_name(name, flags, mode); | |
984 | putname(name); | |
985 | } | |
986 | return file; | |
47c805dc AV |
987 | } |
988 | EXPORT_SYMBOL(filp_open); | |
989 | ||
73d049a4 | 990 | struct file *file_open_root(struct dentry *dentry, struct vfsmount *mnt, |
378c6520 | 991 | const char *filename, int flags, umode_t mode) |
73d049a4 AV |
992 | { |
993 | struct open_flags op; | |
378c6520 | 994 | int err = build_open_flags(flags, mode, &op); |
f9652e10 AV |
995 | if (err) |
996 | return ERR_PTR(err); | |
f9652e10 | 997 | return do_file_open_root(dentry, mnt, filename, &op); |
73d049a4 AV |
998 | } |
999 | EXPORT_SYMBOL(file_open_root); | |
1000 | ||
9a08c352 JB |
1001 | struct file *filp_clone_open(struct file *oldfile) |
1002 | { | |
1003 | struct file *file; | |
1004 | int retval; | |
1005 | ||
1006 | file = get_empty_filp(); | |
1007 | if (IS_ERR(file)) | |
1008 | return file; | |
1009 | ||
1010 | file->f_flags = oldfile->f_flags; | |
1011 | retval = vfs_open(&oldfile->f_path, file, oldfile->f_cred); | |
1012 | if (retval) { | |
1013 | put_filp(file); | |
1014 | return ERR_PTR(retval); | |
1015 | } | |
1016 | ||
1017 | return file; | |
1018 | } | |
1019 | EXPORT_SYMBOL(filp_clone_open); | |
1020 | ||
a218d0fd | 1021 | long do_sys_open(int dfd, const char __user *filename, int flags, umode_t mode) |
1da177e4 | 1022 | { |
47c805dc | 1023 | struct open_flags op; |
f9652e10 AV |
1024 | int fd = build_open_flags(flags, mode, &op); |
1025 | struct filename *tmp; | |
1026 | ||
1027 | if (fd) | |
1028 | return fd; | |
1029 | ||
1030 | tmp = getname(filename); | |
1031 | if (IS_ERR(tmp)) | |
1032 | return PTR_ERR(tmp); | |
1033 | ||
1034 | fd = get_unused_fd_flags(flags); | |
1035 | if (fd >= 0) { | |
1036 | struct file *f = do_filp_open(dfd, tmp, &op); | |
1037 | if (IS_ERR(f)) { | |
1038 | put_unused_fd(fd); | |
1039 | fd = PTR_ERR(f); | |
1040 | } else { | |
1041 | fsnotify_open(f); | |
1042 | fd_install(fd, f); | |
1da177e4 | 1043 | } |
1da177e4 | 1044 | } |
f9652e10 | 1045 | putname(tmp); |
1da177e4 | 1046 | return fd; |
1da177e4 | 1047 | } |
e922efc3 | 1048 | |
a218d0fd | 1049 | SYSCALL_DEFINE3(open, const char __user *, filename, int, flags, umode_t, mode) |
e922efc3 MS |
1050 | { |
1051 | if (force_o_largefile()) | |
1052 | flags |= O_LARGEFILE; | |
1053 | ||
2cf09666 | 1054 | return do_sys_open(AT_FDCWD, filename, flags, mode); |
e922efc3 | 1055 | } |
1da177e4 | 1056 | |
6559eed8 | 1057 | SYSCALL_DEFINE4(openat, int, dfd, const char __user *, filename, int, flags, |
a218d0fd | 1058 | umode_t, mode) |
5590ff0d UD |
1059 | { |
1060 | if (force_o_largefile()) | |
1061 | flags |= O_LARGEFILE; | |
1062 | ||
2cf09666 | 1063 | return do_sys_open(dfd, filename, flags, mode); |
5590ff0d | 1064 | } |
5590ff0d | 1065 | |
1da177e4 LT |
1066 | #ifndef __alpha__ |
1067 | ||
1068 | /* | |
1069 | * For backward compatibility? Maybe this should be moved | |
1070 | * into arch/i386 instead? | |
1071 | */ | |
a218d0fd | 1072 | SYSCALL_DEFINE2(creat, const char __user *, pathname, umode_t, mode) |
1da177e4 LT |
1073 | { |
1074 | return sys_open(pathname, O_CREAT | O_WRONLY | O_TRUNC, mode); | |
1075 | } | |
1076 | ||
1077 | #endif | |
1078 | ||
1079 | /* | |
1080 | * "id" is the POSIX thread ID. We use the | |
1081 | * files pointer for this.. | |
1082 | */ | |
1083 | int filp_close(struct file *filp, fl_owner_t id) | |
1084 | { | |
45778ca8 | 1085 | int retval = 0; |
1da177e4 LT |
1086 | |
1087 | if (!file_count(filp)) { | |
1088 | printk(KERN_ERR "VFS: Close: file count is 0\n"); | |
45778ca8 | 1089 | return 0; |
1da177e4 LT |
1090 | } |
1091 | ||
72c2d531 | 1092 | if (filp->f_op->flush) |
75e1fcc0 | 1093 | retval = filp->f_op->flush(filp, id); |
1da177e4 | 1094 | |
1abf0c71 AV |
1095 | if (likely(!(filp->f_mode & FMODE_PATH))) { |
1096 | dnotify_flush(filp, id); | |
1097 | locks_remove_posix(filp, id); | |
1098 | } | |
1da177e4 LT |
1099 | fput(filp); |
1100 | return retval; | |
1101 | } | |
1102 | ||
1103 | EXPORT_SYMBOL(filp_close); | |
1104 | ||
1105 | /* | |
1106 | * Careful here! We test whether the file pointer is NULL before | |
1107 | * releasing the fd. This ensures that one clone task can't release | |
1108 | * an fd while another clone is opening it. | |
1109 | */ | |
ca013e94 | 1110 | SYSCALL_DEFINE1(close, unsigned int, fd) |
1da177e4 | 1111 | { |
483ce1d4 | 1112 | int retval = __close_fd(current->files, fd); |
ee731f4f EP |
1113 | |
1114 | /* can't restart close syscall because file table entry was cleared */ | |
1115 | if (unlikely(retval == -ERESTARTSYS || | |
1116 | retval == -ERESTARTNOINTR || | |
1117 | retval == -ERESTARTNOHAND || | |
1118 | retval == -ERESTART_RESTARTBLOCK)) | |
1119 | retval = -EINTR; | |
1120 | ||
1121 | return retval; | |
1da177e4 | 1122 | } |
1da177e4 LT |
1123 | EXPORT_SYMBOL(sys_close); |
1124 | ||
1125 | /* | |
1126 | * This routine simulates a hangup on the tty, to arrange that users | |
1127 | * are given clean terminals at login time. | |
1128 | */ | |
ca013e94 | 1129 | SYSCALL_DEFINE0(vhangup) |
1da177e4 LT |
1130 | { |
1131 | if (capable(CAP_SYS_TTY_CONFIG)) { | |
2cb5998b | 1132 | tty_vhangup_self(); |
1da177e4 LT |
1133 | return 0; |
1134 | } | |
1135 | return -EPERM; | |
1136 | } | |
1137 | ||
1138 | /* | |
1139 | * Called when an inode is about to be open. | |
1140 | * We use this to disallow opening large files on 32bit systems if | |
1141 | * the caller didn't specify O_LARGEFILE. On 64bit systems we force | |
1142 | * on this flag in sys_open. | |
1143 | */ | |
1144 | int generic_file_open(struct inode * inode, struct file * filp) | |
1145 | { | |
1146 | if (!(filp->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS) | |
a9c62a18 | 1147 | return -EOVERFLOW; |
1da177e4 LT |
1148 | return 0; |
1149 | } | |
1150 | ||
1151 | EXPORT_SYMBOL(generic_file_open); | |
1152 | ||
1153 | /* | |
1154 | * This is used by subsystems that don't want seekable | |
06b1e104 DT |
1155 | * file descriptors. The function is not supposed to ever fail, the only |
1156 | * reason it returns an 'int' and not 'void' is so that it can be plugged | |
1157 | * directly into file_operations structure. | |
1da177e4 LT |
1158 | */ |
1159 | int nonseekable_open(struct inode *inode, struct file *filp) | |
1160 | { | |
1161 | filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE); | |
1162 | return 0; | |
1163 | } | |
1164 | ||
1165 | EXPORT_SYMBOL(nonseekable_open); |