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> |
1da177e4 | 10 | #include <linux/quotaops.h> |
0eeca283 | 11 | #include <linux/fsnotify.h> |
1da177e4 LT |
12 | #include <linux/module.h> |
13 | #include <linux/slab.h> | |
14 | #include <linux/tty.h> | |
15 | #include <linux/namei.h> | |
16 | #include <linux/backing-dev.h> | |
16f7e0fe | 17 | #include <linux/capability.h> |
1da177e4 LT |
18 | #include <linux/security.h> |
19 | #include <linux/mount.h> | |
20 | #include <linux/vfs.h> | |
5590ff0d | 21 | #include <linux/fcntl.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> |
1da177e4 | 30 | |
726c3342 | 31 | int vfs_statfs(struct dentry *dentry, struct kstatfs *buf) |
1da177e4 LT |
32 | { |
33 | int retval = -ENODEV; | |
34 | ||
726c3342 | 35 | if (dentry) { |
1da177e4 | 36 | retval = -ENOSYS; |
726c3342 | 37 | if (dentry->d_sb->s_op->statfs) { |
1da177e4 | 38 | memset(buf, 0, sizeof(*buf)); |
726c3342 | 39 | retval = security_sb_statfs(dentry); |
1da177e4 LT |
40 | if (retval) |
41 | return retval; | |
726c3342 | 42 | retval = dentry->d_sb->s_op->statfs(dentry, buf); |
1da177e4 LT |
43 | if (retval == 0 && buf->f_frsize == 0) |
44 | buf->f_frsize = buf->f_bsize; | |
45 | } | |
46 | } | |
47 | return retval; | |
48 | } | |
49 | ||
50 | EXPORT_SYMBOL(vfs_statfs); | |
51 | ||
726c3342 | 52 | static int vfs_statfs_native(struct dentry *dentry, struct statfs *buf) |
1da177e4 LT |
53 | { |
54 | struct kstatfs st; | |
55 | int retval; | |
56 | ||
726c3342 | 57 | retval = vfs_statfs(dentry, &st); |
1da177e4 LT |
58 | if (retval) |
59 | return retval; | |
60 | ||
61 | if (sizeof(*buf) == sizeof(st)) | |
62 | memcpy(buf, &st, sizeof(st)); | |
63 | else { | |
64 | if (sizeof buf->f_blocks == 4) { | |
65 | if ((st.f_blocks | st.f_bfree | st.f_bavail) & | |
66 | 0xffffffff00000000ULL) | |
67 | return -EOVERFLOW; | |
68 | /* | |
69 | * f_files and f_ffree may be -1; it's okay to stuff | |
70 | * that into 32 bits | |
71 | */ | |
72 | if (st.f_files != -1 && | |
73 | (st.f_files & 0xffffffff00000000ULL)) | |
74 | return -EOVERFLOW; | |
75 | if (st.f_ffree != -1 && | |
76 | (st.f_ffree & 0xffffffff00000000ULL)) | |
77 | return -EOVERFLOW; | |
78 | } | |
79 | ||
80 | buf->f_type = st.f_type; | |
81 | buf->f_bsize = st.f_bsize; | |
82 | buf->f_blocks = st.f_blocks; | |
83 | buf->f_bfree = st.f_bfree; | |
84 | buf->f_bavail = st.f_bavail; | |
85 | buf->f_files = st.f_files; | |
86 | buf->f_ffree = st.f_ffree; | |
87 | buf->f_fsid = st.f_fsid; | |
88 | buf->f_namelen = st.f_namelen; | |
89 | buf->f_frsize = st.f_frsize; | |
90 | memset(buf->f_spare, 0, sizeof(buf->f_spare)); | |
91 | } | |
92 | return 0; | |
93 | } | |
94 | ||
726c3342 | 95 | static int vfs_statfs64(struct dentry *dentry, struct statfs64 *buf) |
1da177e4 LT |
96 | { |
97 | struct kstatfs st; | |
98 | int retval; | |
99 | ||
726c3342 | 100 | retval = vfs_statfs(dentry, &st); |
1da177e4 LT |
101 | if (retval) |
102 | return retval; | |
103 | ||
104 | if (sizeof(*buf) == sizeof(st)) | |
105 | memcpy(buf, &st, sizeof(st)); | |
106 | else { | |
107 | buf->f_type = st.f_type; | |
108 | buf->f_bsize = st.f_bsize; | |
109 | buf->f_blocks = st.f_blocks; | |
110 | buf->f_bfree = st.f_bfree; | |
111 | buf->f_bavail = st.f_bavail; | |
112 | buf->f_files = st.f_files; | |
113 | buf->f_ffree = st.f_ffree; | |
114 | buf->f_fsid = st.f_fsid; | |
115 | buf->f_namelen = st.f_namelen; | |
116 | buf->f_frsize = st.f_frsize; | |
117 | memset(buf->f_spare, 0, sizeof(buf->f_spare)); | |
118 | } | |
119 | return 0; | |
120 | } | |
121 | ||
122 | asmlinkage long sys_statfs(const char __user * path, struct statfs __user * buf) | |
123 | { | |
124 | struct nameidata nd; | |
125 | int error; | |
126 | ||
127 | error = user_path_walk(path, &nd); | |
128 | if (!error) { | |
129 | struct statfs tmp; | |
4ac91378 | 130 | error = vfs_statfs_native(nd.path.dentry, &tmp); |
1da177e4 LT |
131 | if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) |
132 | error = -EFAULT; | |
1d957f9b | 133 | path_put(&nd.path); |
1da177e4 LT |
134 | } |
135 | return error; | |
136 | } | |
137 | ||
138 | ||
139 | asmlinkage long sys_statfs64(const char __user *path, size_t sz, struct statfs64 __user *buf) | |
140 | { | |
141 | struct nameidata nd; | |
142 | long error; | |
143 | ||
144 | if (sz != sizeof(*buf)) | |
145 | return -EINVAL; | |
146 | error = user_path_walk(path, &nd); | |
147 | if (!error) { | |
148 | struct statfs64 tmp; | |
4ac91378 | 149 | error = vfs_statfs64(nd.path.dentry, &tmp); |
1da177e4 LT |
150 | if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) |
151 | error = -EFAULT; | |
1d957f9b | 152 | path_put(&nd.path); |
1da177e4 LT |
153 | } |
154 | return error; | |
155 | } | |
156 | ||
157 | ||
158 | asmlinkage long sys_fstatfs(unsigned int fd, struct statfs __user * buf) | |
159 | { | |
160 | struct file * file; | |
161 | struct statfs tmp; | |
162 | int error; | |
163 | ||
164 | error = -EBADF; | |
165 | file = fget(fd); | |
166 | if (!file) | |
167 | goto out; | |
0f7fc9e4 | 168 | error = vfs_statfs_native(file->f_path.dentry, &tmp); |
1da177e4 LT |
169 | if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) |
170 | error = -EFAULT; | |
171 | fput(file); | |
172 | out: | |
173 | return error; | |
174 | } | |
175 | ||
176 | asmlinkage long sys_fstatfs64(unsigned int fd, size_t sz, struct statfs64 __user *buf) | |
177 | { | |
178 | struct file * file; | |
179 | struct statfs64 tmp; | |
180 | int error; | |
181 | ||
182 | if (sz != sizeof(*buf)) | |
183 | return -EINVAL; | |
184 | ||
185 | error = -EBADF; | |
186 | file = fget(fd); | |
187 | if (!file) | |
188 | goto out; | |
0f7fc9e4 | 189 | error = vfs_statfs64(file->f_path.dentry, &tmp); |
1da177e4 LT |
190 | if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) |
191 | error = -EFAULT; | |
192 | fput(file); | |
193 | out: | |
194 | return error; | |
195 | } | |
196 | ||
4a30131e N |
197 | int do_truncate(struct dentry *dentry, loff_t length, unsigned int time_attrs, |
198 | struct file *filp) | |
1da177e4 LT |
199 | { |
200 | int err; | |
201 | struct iattr newattrs; | |
202 | ||
203 | /* Not pretty: "inode->i_size" shouldn't really be signed. But it is. */ | |
204 | if (length < 0) | |
205 | return -EINVAL; | |
206 | ||
207 | newattrs.ia_size = length; | |
4a30131e | 208 | newattrs.ia_valid = ATTR_SIZE | time_attrs; |
cc4e69de MS |
209 | if (filp) { |
210 | newattrs.ia_file = filp; | |
211 | newattrs.ia_valid |= ATTR_FILE; | |
212 | } | |
1da177e4 | 213 | |
7b82dc0e LT |
214 | /* Remove suid/sgid on truncate too */ |
215 | newattrs.ia_valid |= should_remove_suid(dentry); | |
216 | ||
1b1dcc1b | 217 | mutex_lock(&dentry->d_inode->i_mutex); |
1da177e4 | 218 | err = notify_change(dentry, &newattrs); |
1b1dcc1b | 219 | mutex_unlock(&dentry->d_inode->i_mutex); |
1da177e4 LT |
220 | return err; |
221 | } | |
222 | ||
b01ec0ef | 223 | static long do_sys_truncate(const char __user * path, loff_t length) |
1da177e4 LT |
224 | { |
225 | struct nameidata nd; | |
226 | struct inode * inode; | |
227 | int error; | |
228 | ||
229 | error = -EINVAL; | |
230 | if (length < 0) /* sorry, but loff_t says... */ | |
231 | goto out; | |
232 | ||
233 | error = user_path_walk(path, &nd); | |
234 | if (error) | |
235 | goto out; | |
4ac91378 | 236 | inode = nd.path.dentry->d_inode; |
1da177e4 LT |
237 | |
238 | /* For directories it's -EISDIR, for other non-regulars - -EINVAL */ | |
239 | error = -EISDIR; | |
240 | if (S_ISDIR(inode->i_mode)) | |
241 | goto dput_and_out; | |
242 | ||
243 | error = -EINVAL; | |
244 | if (!S_ISREG(inode->i_mode)) | |
245 | goto dput_and_out; | |
246 | ||
9ac9b847 | 247 | error = mnt_want_write(nd.path.mnt); |
1da177e4 LT |
248 | if (error) |
249 | goto dput_and_out; | |
250 | ||
9ac9b847 DH |
251 | error = vfs_permission(&nd, MAY_WRITE); |
252 | if (error) | |
253 | goto mnt_drop_write_and_out; | |
1da177e4 LT |
254 | |
255 | error = -EPERM; | |
256 | if (IS_IMMUTABLE(inode) || IS_APPEND(inode)) | |
9ac9b847 | 257 | goto mnt_drop_write_and_out; |
1da177e4 | 258 | |
9700382c | 259 | error = get_write_access(inode); |
1da177e4 | 260 | if (error) |
9ac9b847 | 261 | goto mnt_drop_write_and_out; |
1da177e4 | 262 | |
9700382c | 263 | /* |
264 | * Make sure that there are no leases. get_write_access() protects | |
265 | * against the truncate racing with a lease-granting setlease(). | |
266 | */ | |
267 | error = break_lease(inode, FMODE_WRITE); | |
1da177e4 | 268 | if (error) |
9700382c | 269 | goto put_write_and_out; |
1da177e4 LT |
270 | |
271 | error = locks_verify_truncate(inode, NULL, length); | |
272 | if (!error) { | |
273 | DQUOT_INIT(inode); | |
4ac91378 | 274 | error = do_truncate(nd.path.dentry, length, 0, NULL); |
1da177e4 | 275 | } |
1da177e4 | 276 | |
9700382c | 277 | put_write_and_out: |
278 | put_write_access(inode); | |
9ac9b847 DH |
279 | mnt_drop_write_and_out: |
280 | mnt_drop_write(nd.path.mnt); | |
1da177e4 | 281 | dput_and_out: |
1d957f9b | 282 | path_put(&nd.path); |
1da177e4 LT |
283 | out: |
284 | return error; | |
285 | } | |
286 | ||
287 | asmlinkage long sys_truncate(const char __user * path, unsigned long length) | |
288 | { | |
289 | /* on 32-bit boxen it will cut the range 2^31--2^32-1 off */ | |
290 | return do_sys_truncate(path, (long)length); | |
291 | } | |
292 | ||
b01ec0ef | 293 | static long do_sys_ftruncate(unsigned int fd, loff_t length, int small) |
1da177e4 LT |
294 | { |
295 | struct inode * inode; | |
296 | struct dentry *dentry; | |
297 | struct file * file; | |
298 | int error; | |
299 | ||
300 | error = -EINVAL; | |
301 | if (length < 0) | |
302 | goto out; | |
303 | error = -EBADF; | |
304 | file = fget(fd); | |
305 | if (!file) | |
306 | goto out; | |
307 | ||
308 | /* explicitly opened as large or we are on 64-bit box */ | |
309 | if (file->f_flags & O_LARGEFILE) | |
310 | small = 0; | |
311 | ||
0f7fc9e4 | 312 | dentry = file->f_path.dentry; |
1da177e4 LT |
313 | inode = dentry->d_inode; |
314 | error = -EINVAL; | |
315 | if (!S_ISREG(inode->i_mode) || !(file->f_mode & FMODE_WRITE)) | |
316 | goto out_putf; | |
317 | ||
318 | error = -EINVAL; | |
319 | /* Cannot ftruncate over 2^31 bytes without large file support */ | |
320 | if (small && length > MAX_NON_LFS) | |
321 | goto out_putf; | |
322 | ||
323 | error = -EPERM; | |
324 | if (IS_APPEND(inode)) | |
325 | goto out_putf; | |
326 | ||
327 | error = locks_verify_truncate(inode, file, length); | |
328 | if (!error) | |
6e656be8 | 329 | error = do_truncate(dentry, length, ATTR_MTIME|ATTR_CTIME, file); |
1da177e4 LT |
330 | out_putf: |
331 | fput(file); | |
332 | out: | |
333 | return error; | |
334 | } | |
335 | ||
336 | asmlinkage long sys_ftruncate(unsigned int fd, unsigned long length) | |
337 | { | |
0a489cb3 | 338 | long ret = do_sys_ftruncate(fd, length, 1); |
385910f2 | 339 | /* avoid REGPARM breakage on x86: */ |
54a01510 | 340 | asmlinkage_protect(2, ret, fd, length); |
0a489cb3 | 341 | return ret; |
1da177e4 LT |
342 | } |
343 | ||
344 | /* LFS versions of truncate are only needed on 32 bit machines */ | |
345 | #if BITS_PER_LONG == 32 | |
346 | asmlinkage long sys_truncate64(const char __user * path, loff_t length) | |
347 | { | |
348 | return do_sys_truncate(path, length); | |
349 | } | |
350 | ||
351 | asmlinkage long sys_ftruncate64(unsigned int fd, loff_t length) | |
352 | { | |
0a489cb3 | 353 | long ret = do_sys_ftruncate(fd, length, 0); |
385910f2 | 354 | /* avoid REGPARM breakage on x86: */ |
54a01510 | 355 | asmlinkage_protect(2, ret, fd, length); |
0a489cb3 | 356 | return ret; |
1da177e4 LT |
357 | } |
358 | #endif | |
359 | ||
97ac7350 AA |
360 | asmlinkage long sys_fallocate(int fd, int mode, loff_t offset, loff_t len) |
361 | { | |
362 | struct file *file; | |
363 | struct inode *inode; | |
364 | long ret = -EINVAL; | |
365 | ||
366 | if (offset < 0 || len <= 0) | |
367 | goto out; | |
368 | ||
369 | /* Return error if mode is not supported */ | |
370 | ret = -EOPNOTSUPP; | |
371 | if (mode && !(mode & FALLOC_FL_KEEP_SIZE)) | |
372 | goto out; | |
373 | ||
374 | ret = -EBADF; | |
375 | file = fget(fd); | |
376 | if (!file) | |
377 | goto out; | |
378 | if (!(file->f_mode & FMODE_WRITE)) | |
379 | goto out_fput; | |
380 | /* | |
381 | * Revalidate the write permissions, in case security policy has | |
382 | * changed since the files were opened. | |
383 | */ | |
384 | ret = security_file_permission(file, MAY_WRITE); | |
385 | if (ret) | |
386 | goto out_fput; | |
387 | ||
388 | inode = file->f_path.dentry->d_inode; | |
389 | ||
390 | ret = -ESPIPE; | |
391 | if (S_ISFIFO(inode->i_mode)) | |
392 | goto out_fput; | |
393 | ||
394 | ret = -ENODEV; | |
395 | /* | |
396 | * Let individual file system decide if it supports preallocation | |
397 | * for directories or not. | |
398 | */ | |
399 | if (!S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode)) | |
400 | goto out_fput; | |
401 | ||
402 | ret = -EFBIG; | |
403 | /* Check for wrap through zero too */ | |
404 | if (((offset + len) > inode->i_sb->s_maxbytes) || ((offset + len) < 0)) | |
405 | goto out_fput; | |
406 | ||
407 | if (inode->i_op && inode->i_op->fallocate) | |
408 | ret = inode->i_op->fallocate(inode, mode, offset, len); | |
409 | else | |
0d786d4a | 410 | ret = -EOPNOTSUPP; |
97ac7350 AA |
411 | |
412 | out_fput: | |
413 | fput(file); | |
414 | out: | |
415 | return ret; | |
416 | } | |
417 | ||
1da177e4 LT |
418 | /* |
419 | * access() needs to use the real uid/gid, not the effective uid/gid. | |
420 | * We do this by temporarily clearing all FS-related capabilities and | |
421 | * switching the fsuid/fsgid around to the real ones. | |
422 | */ | |
5590ff0d | 423 | asmlinkage long sys_faccessat(int dfd, const char __user *filename, int mode) |
1da177e4 LT |
424 | { |
425 | struct nameidata nd; | |
426 | int old_fsuid, old_fsgid; | |
427 | kernel_cap_t old_cap; | |
428 | int res; | |
429 | ||
430 | if (mode & ~S_IRWXO) /* where's F_OK, X_OK, W_OK, R_OK? */ | |
431 | return -EINVAL; | |
432 | ||
433 | old_fsuid = current->fsuid; | |
434 | old_fsgid = current->fsgid; | |
435 | old_cap = current->cap_effective; | |
436 | ||
437 | current->fsuid = current->uid; | |
438 | current->fsgid = current->gid; | |
439 | ||
440 | /* | |
441 | * Clear the capabilities if we switch to a non-root user | |
442 | * | |
443 | * FIXME: There is a race here against sys_capset. The | |
444 | * capabilities can change yet we will restore the old | |
445 | * value below. We should hold task_capabilities_lock, | |
446 | * but we cannot because user_path_walk can sleep. | |
447 | */ | |
448 | if (current->uid) | |
449 | cap_clear(current->cap_effective); | |
450 | else | |
451 | current->cap_effective = current->cap_permitted; | |
452 | ||
5590ff0d | 453 | res = __user_walk_fd(dfd, filename, LOOKUP_FOLLOW|LOOKUP_ACCESS, &nd); |
6902d925 DH |
454 | if (res) |
455 | goto out; | |
456 | ||
457 | res = vfs_permission(&nd, mode); | |
458 | /* SuS v2 requires we report a read only fs too */ | |
459 | if(res || !(mode & S_IWOTH) || | |
4ac91378 | 460 | special_file(nd.path.dentry->d_inode->i_mode)) |
6902d925 | 461 | goto out_path_release; |
2f676cbc DH |
462 | /* |
463 | * This is a rare case where using __mnt_is_readonly() | |
464 | * is OK without a mnt_want/drop_write() pair. Since | |
465 | * no actual write to the fs is performed here, we do | |
466 | * not need to telegraph to that to anyone. | |
467 | * | |
468 | * By doing this, we accept that this access is | |
469 | * inherently racy and know that the fs may change | |
470 | * state before we even see this result. | |
471 | */ | |
472 | if (__mnt_is_readonly(nd.path.mnt)) | |
6902d925 | 473 | res = -EROFS; |
1da177e4 | 474 | |
6902d925 | 475 | out_path_release: |
1d957f9b | 476 | path_put(&nd.path); |
6902d925 | 477 | out: |
1da177e4 LT |
478 | current->fsuid = old_fsuid; |
479 | current->fsgid = old_fsgid; | |
480 | current->cap_effective = old_cap; | |
481 | ||
482 | return res; | |
483 | } | |
484 | ||
5590ff0d UD |
485 | asmlinkage long sys_access(const char __user *filename, int mode) |
486 | { | |
487 | return sys_faccessat(AT_FDCWD, filename, mode); | |
488 | } | |
489 | ||
1da177e4 LT |
490 | asmlinkage long sys_chdir(const char __user * filename) |
491 | { | |
492 | struct nameidata nd; | |
493 | int error; | |
494 | ||
650a8983 MS |
495 | error = __user_walk(filename, |
496 | LOOKUP_FOLLOW|LOOKUP_DIRECTORY|LOOKUP_CHDIR, &nd); | |
1da177e4 LT |
497 | if (error) |
498 | goto out; | |
499 | ||
e4543edd | 500 | error = vfs_permission(&nd, MAY_EXEC); |
1da177e4 LT |
501 | if (error) |
502 | goto dput_and_out; | |
503 | ||
ac748a09 | 504 | set_fs_pwd(current->fs, &nd.path); |
1da177e4 LT |
505 | |
506 | dput_and_out: | |
1d957f9b | 507 | path_put(&nd.path); |
1da177e4 LT |
508 | out: |
509 | return error; | |
510 | } | |
511 | ||
512 | asmlinkage long sys_fchdir(unsigned int fd) | |
513 | { | |
514 | struct file *file; | |
1da177e4 | 515 | struct inode *inode; |
1da177e4 LT |
516 | int error; |
517 | ||
518 | error = -EBADF; | |
519 | file = fget(fd); | |
520 | if (!file) | |
521 | goto out; | |
522 | ||
ac748a09 | 523 | inode = file->f_path.dentry->d_inode; |
1da177e4 LT |
524 | |
525 | error = -ENOTDIR; | |
526 | if (!S_ISDIR(inode->i_mode)) | |
527 | goto out_putf; | |
528 | ||
8c744fb8 | 529 | error = file_permission(file, MAY_EXEC); |
1da177e4 | 530 | if (!error) |
ac748a09 | 531 | set_fs_pwd(current->fs, &file->f_path); |
1da177e4 LT |
532 | out_putf: |
533 | fput(file); | |
534 | out: | |
535 | return error; | |
536 | } | |
537 | ||
538 | asmlinkage long sys_chroot(const char __user * filename) | |
539 | { | |
540 | struct nameidata nd; | |
541 | int error; | |
542 | ||
543 | error = __user_walk(filename, LOOKUP_FOLLOW | LOOKUP_DIRECTORY | LOOKUP_NOALT, &nd); | |
544 | if (error) | |
545 | goto out; | |
546 | ||
e4543edd | 547 | error = vfs_permission(&nd, MAY_EXEC); |
1da177e4 LT |
548 | if (error) |
549 | goto dput_and_out; | |
550 | ||
551 | error = -EPERM; | |
552 | if (!capable(CAP_SYS_CHROOT)) | |
553 | goto dput_and_out; | |
554 | ||
ac748a09 | 555 | set_fs_root(current->fs, &nd.path); |
1da177e4 LT |
556 | set_fs_altroot(); |
557 | error = 0; | |
558 | dput_and_out: | |
1d957f9b | 559 | path_put(&nd.path); |
1da177e4 LT |
560 | out: |
561 | return error; | |
562 | } | |
563 | ||
564 | asmlinkage long sys_fchmod(unsigned int fd, mode_t mode) | |
565 | { | |
566 | struct inode * inode; | |
567 | struct dentry * dentry; | |
568 | struct file * file; | |
569 | int err = -EBADF; | |
570 | struct iattr newattrs; | |
571 | ||
572 | file = fget(fd); | |
573 | if (!file) | |
574 | goto out; | |
575 | ||
0f7fc9e4 | 576 | dentry = file->f_path.dentry; |
1da177e4 LT |
577 | inode = dentry->d_inode; |
578 | ||
5a190ae6 | 579 | audit_inode(NULL, dentry); |
73241ccc | 580 | |
2af482a7 DH |
581 | err = mnt_want_write(file->f_path.mnt); |
582 | if (err) | |
1da177e4 LT |
583 | goto out_putf; |
584 | err = -EPERM; | |
585 | if (IS_IMMUTABLE(inode) || IS_APPEND(inode)) | |
2af482a7 | 586 | goto out_drop_write; |
1b1dcc1b | 587 | mutex_lock(&inode->i_mutex); |
1da177e4 LT |
588 | if (mode == (mode_t) -1) |
589 | mode = inode->i_mode; | |
590 | newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO); | |
591 | newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; | |
592 | err = notify_change(dentry, &newattrs); | |
1b1dcc1b | 593 | mutex_unlock(&inode->i_mutex); |
1da177e4 | 594 | |
2af482a7 DH |
595 | out_drop_write: |
596 | mnt_drop_write(file->f_path.mnt); | |
1da177e4 LT |
597 | out_putf: |
598 | fput(file); | |
599 | out: | |
600 | return err; | |
601 | } | |
602 | ||
5590ff0d UD |
603 | asmlinkage long sys_fchmodat(int dfd, const char __user *filename, |
604 | mode_t mode) | |
1da177e4 LT |
605 | { |
606 | struct nameidata nd; | |
607 | struct inode * inode; | |
608 | int error; | |
609 | struct iattr newattrs; | |
610 | ||
5590ff0d | 611 | error = __user_walk_fd(dfd, filename, LOOKUP_FOLLOW, &nd); |
1da177e4 LT |
612 | if (error) |
613 | goto out; | |
4ac91378 | 614 | inode = nd.path.dentry->d_inode; |
1da177e4 | 615 | |
2af482a7 DH |
616 | error = mnt_want_write(nd.path.mnt); |
617 | if (error) | |
1da177e4 LT |
618 | goto dput_and_out; |
619 | ||
620 | error = -EPERM; | |
621 | if (IS_IMMUTABLE(inode) || IS_APPEND(inode)) | |
2af482a7 | 622 | goto out_drop_write; |
1da177e4 | 623 | |
1b1dcc1b | 624 | mutex_lock(&inode->i_mutex); |
1da177e4 LT |
625 | if (mode == (mode_t) -1) |
626 | mode = inode->i_mode; | |
627 | newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO); | |
628 | newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; | |
4ac91378 | 629 | error = notify_change(nd.path.dentry, &newattrs); |
1b1dcc1b | 630 | mutex_unlock(&inode->i_mutex); |
1da177e4 | 631 | |
2af482a7 DH |
632 | out_drop_write: |
633 | mnt_drop_write(nd.path.mnt); | |
1da177e4 | 634 | dput_and_out: |
1d957f9b | 635 | path_put(&nd.path); |
1da177e4 LT |
636 | out: |
637 | return error; | |
638 | } | |
639 | ||
5590ff0d UD |
640 | asmlinkage long sys_chmod(const char __user *filename, mode_t mode) |
641 | { | |
642 | return sys_fchmodat(AT_FDCWD, filename, mode); | |
643 | } | |
644 | ||
1da177e4 LT |
645 | static int chown_common(struct dentry * dentry, uid_t user, gid_t group) |
646 | { | |
647 | struct inode * inode; | |
648 | int error; | |
649 | struct iattr newattrs; | |
650 | ||
651 | error = -ENOENT; | |
652 | if (!(inode = dentry->d_inode)) { | |
653 | printk(KERN_ERR "chown_common: NULL inode\n"); | |
654 | goto out; | |
655 | } | |
1da177e4 LT |
656 | error = -EPERM; |
657 | if (IS_IMMUTABLE(inode) || IS_APPEND(inode)) | |
658 | goto out; | |
659 | newattrs.ia_valid = ATTR_CTIME; | |
660 | if (user != (uid_t) -1) { | |
661 | newattrs.ia_valid |= ATTR_UID; | |
662 | newattrs.ia_uid = user; | |
663 | } | |
664 | if (group != (gid_t) -1) { | |
665 | newattrs.ia_valid |= ATTR_GID; | |
666 | newattrs.ia_gid = group; | |
667 | } | |
668 | if (!S_ISDIR(inode->i_mode)) | |
b5376771 SH |
669 | newattrs.ia_valid |= |
670 | ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV; | |
1b1dcc1b | 671 | mutex_lock(&inode->i_mutex); |
1da177e4 | 672 | error = notify_change(dentry, &newattrs); |
1b1dcc1b | 673 | mutex_unlock(&inode->i_mutex); |
1da177e4 LT |
674 | out: |
675 | return error; | |
676 | } | |
677 | ||
678 | asmlinkage long sys_chown(const char __user * filename, uid_t user, gid_t group) | |
679 | { | |
680 | struct nameidata nd; | |
681 | int error; | |
682 | ||
683 | error = user_path_walk(filename, &nd); | |
6902d925 DH |
684 | if (error) |
685 | goto out; | |
2af482a7 DH |
686 | error = mnt_want_write(nd.path.mnt); |
687 | if (error) | |
688 | goto out_release; | |
4ac91378 | 689 | error = chown_common(nd.path.dentry, user, group); |
2af482a7 DH |
690 | mnt_drop_write(nd.path.mnt); |
691 | out_release: | |
1d957f9b | 692 | path_put(&nd.path); |
6902d925 | 693 | out: |
1da177e4 LT |
694 | return error; |
695 | } | |
696 | ||
5590ff0d UD |
697 | asmlinkage long sys_fchownat(int dfd, const char __user *filename, uid_t user, |
698 | gid_t group, int flag) | |
699 | { | |
700 | struct nameidata nd; | |
701 | int error = -EINVAL; | |
702 | int follow; | |
703 | ||
704 | if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0) | |
705 | goto out; | |
706 | ||
707 | follow = (flag & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW; | |
708 | error = __user_walk_fd(dfd, filename, follow, &nd); | |
6902d925 DH |
709 | if (error) |
710 | goto out; | |
2af482a7 DH |
711 | error = mnt_want_write(nd.path.mnt); |
712 | if (error) | |
713 | goto out_release; | |
4ac91378 | 714 | error = chown_common(nd.path.dentry, user, group); |
2af482a7 DH |
715 | mnt_drop_write(nd.path.mnt); |
716 | out_release: | |
1d957f9b | 717 | path_put(&nd.path); |
5590ff0d UD |
718 | out: |
719 | return error; | |
720 | } | |
721 | ||
1da177e4 LT |
722 | asmlinkage long sys_lchown(const char __user * filename, uid_t user, gid_t group) |
723 | { | |
724 | struct nameidata nd; | |
725 | int error; | |
726 | ||
727 | error = user_path_walk_link(filename, &nd); | |
6902d925 DH |
728 | if (error) |
729 | goto out; | |
2af482a7 DH |
730 | error = mnt_want_write(nd.path.mnt); |
731 | if (error) | |
732 | goto out_release; | |
4ac91378 | 733 | error = chown_common(nd.path.dentry, user, group); |
2af482a7 DH |
734 | mnt_drop_write(nd.path.mnt); |
735 | out_release: | |
1d957f9b | 736 | path_put(&nd.path); |
6902d925 | 737 | out: |
1da177e4 LT |
738 | return error; |
739 | } | |
740 | ||
741 | ||
742 | asmlinkage long sys_fchown(unsigned int fd, uid_t user, gid_t group) | |
743 | { | |
744 | struct file * file; | |
745 | int error = -EBADF; | |
6902d925 | 746 | struct dentry * dentry; |
1da177e4 LT |
747 | |
748 | file = fget(fd); | |
6902d925 DH |
749 | if (!file) |
750 | goto out; | |
751 | ||
2af482a7 DH |
752 | error = mnt_want_write(file->f_path.mnt); |
753 | if (error) | |
754 | goto out_fput; | |
0f7fc9e4 | 755 | dentry = file->f_path.dentry; |
5a190ae6 | 756 | audit_inode(NULL, dentry); |
6902d925 | 757 | error = chown_common(dentry, user, group); |
2af482a7 DH |
758 | mnt_drop_write(file->f_path.mnt); |
759 | out_fput: | |
6902d925 DH |
760 | fput(file); |
761 | out: | |
1da177e4 LT |
762 | return error; |
763 | } | |
764 | ||
4a3fd211 DH |
765 | /* |
766 | * You have to be very careful that these write | |
767 | * counts get cleaned up in error cases and | |
768 | * upon __fput(). This should probably never | |
769 | * be called outside of __dentry_open(). | |
770 | */ | |
771 | static inline int __get_file_write_access(struct inode *inode, | |
772 | struct vfsmount *mnt) | |
773 | { | |
774 | int error; | |
775 | error = get_write_access(inode); | |
776 | if (error) | |
777 | return error; | |
778 | /* | |
779 | * Do not take mount writer counts on | |
780 | * special files since no writes to | |
781 | * the mount itself will occur. | |
782 | */ | |
783 | if (!special_file(inode->i_mode)) { | |
784 | /* | |
785 | * Balanced in __fput() | |
786 | */ | |
787 | error = mnt_want_write(mnt); | |
788 | if (error) | |
789 | put_write_access(inode); | |
790 | } | |
791 | return error; | |
792 | } | |
793 | ||
a1a5b3d9 | 794 | static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt, |
834f2a4a TM |
795 | int flags, struct file *f, |
796 | int (*open)(struct inode *, struct file *)) | |
1da177e4 | 797 | { |
1da177e4 LT |
798 | struct inode *inode; |
799 | int error; | |
800 | ||
1da177e4 | 801 | f->f_flags = flags; |
a1a5b3d9 PS |
802 | f->f_mode = ((flags+1) & O_ACCMODE) | FMODE_LSEEK | |
803 | FMODE_PREAD | FMODE_PWRITE; | |
1da177e4 LT |
804 | inode = dentry->d_inode; |
805 | if (f->f_mode & FMODE_WRITE) { | |
4a3fd211 | 806 | error = __get_file_write_access(inode, mnt); |
1da177e4 LT |
807 | if (error) |
808 | goto cleanup_file; | |
ad775f5a DH |
809 | if (!special_file(inode->i_mode)) |
810 | file_take_write(f); | |
1da177e4 LT |
811 | } |
812 | ||
813 | f->f_mapping = inode->i_mapping; | |
0f7fc9e4 JJS |
814 | f->f_path.dentry = dentry; |
815 | f->f_path.mnt = mnt; | |
1da177e4 LT |
816 | f->f_pos = 0; |
817 | f->f_op = fops_get(inode->i_fop); | |
818 | file_move(f, &inode->i_sb->s_files); | |
819 | ||
788e7dd4 YN |
820 | error = security_dentry_open(f); |
821 | if (error) | |
822 | goto cleanup_all; | |
823 | ||
834f2a4a TM |
824 | if (!open && f->f_op) |
825 | open = f->f_op->open; | |
826 | if (open) { | |
827 | error = open(inode, f); | |
1da177e4 LT |
828 | if (error) |
829 | goto cleanup_all; | |
830 | } | |
834f2a4a | 831 | |
1da177e4 LT |
832 | f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC); |
833 | ||
834 | file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping); | |
835 | ||
836 | /* NB: we're sure to have correct a_ops only after f_op->open */ | |
837 | if (f->f_flags & O_DIRECT) { | |
ceffc078 CO |
838 | if (!f->f_mapping->a_ops || |
839 | ((!f->f_mapping->a_ops->direct_IO) && | |
840 | (!f->f_mapping->a_ops->get_xip_page))) { | |
1da177e4 LT |
841 | fput(f); |
842 | f = ERR_PTR(-EINVAL); | |
843 | } | |
844 | } | |
845 | ||
846 | return f; | |
847 | ||
848 | cleanup_all: | |
849 | fops_put(f->f_op); | |
4a3fd211 | 850 | if (f->f_mode & FMODE_WRITE) { |
1da177e4 | 851 | put_write_access(inode); |
ad775f5a DH |
852 | if (!special_file(inode->i_mode)) { |
853 | /* | |
854 | * We don't consider this a real | |
855 | * mnt_want/drop_write() pair | |
856 | * because it all happenend right | |
857 | * here, so just reset the state. | |
858 | */ | |
859 | file_reset_write(f); | |
4a3fd211 | 860 | mnt_drop_write(mnt); |
ad775f5a | 861 | } |
4a3fd211 | 862 | } |
1da177e4 | 863 | file_kill(f); |
0f7fc9e4 JJS |
864 | f->f_path.dentry = NULL; |
865 | f->f_path.mnt = NULL; | |
1da177e4 LT |
866 | cleanup_file: |
867 | put_filp(f); | |
1da177e4 LT |
868 | dput(dentry); |
869 | mntput(mnt); | |
870 | return ERR_PTR(error); | |
871 | } | |
872 | ||
834f2a4a TM |
873 | /** |
874 | * lookup_instantiate_filp - instantiates the open intent filp | |
875 | * @nd: pointer to nameidata | |
876 | * @dentry: pointer to dentry | |
877 | * @open: open callback | |
878 | * | |
879 | * Helper for filesystems that want to use lookup open intents and pass back | |
880 | * a fully instantiated struct file to the caller. | |
881 | * This function is meant to be called from within a filesystem's | |
882 | * lookup method. | |
9a56c213 OD |
883 | * Beware of calling it for non-regular files! Those ->open methods might block |
884 | * (e.g. in fifo_open), leaving you with parent locked (and in case of fifo, | |
885 | * leading to a deadlock, as nobody can open that fifo anymore, because | |
886 | * another process to open fifo will block on locked parent when doing lookup). | |
834f2a4a TM |
887 | * Note that in case of error, nd->intent.open.file is destroyed, but the |
888 | * path information remains valid. | |
889 | * If the open callback is set to NULL, then the standard f_op->open() | |
890 | * filesystem callback is substituted. | |
891 | */ | |
892 | struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry *dentry, | |
893 | int (*open)(struct inode *, struct file *)) | |
894 | { | |
895 | if (IS_ERR(nd->intent.open.file)) | |
896 | goto out; | |
897 | if (IS_ERR(dentry)) | |
898 | goto out_err; | |
4ac91378 | 899 | nd->intent.open.file = __dentry_open(dget(dentry), mntget(nd->path.mnt), |
834f2a4a TM |
900 | nd->intent.open.flags - 1, |
901 | nd->intent.open.file, | |
902 | open); | |
903 | out: | |
904 | return nd->intent.open.file; | |
905 | out_err: | |
906 | release_open_intent(nd); | |
907 | nd->intent.open.file = (struct file *)dentry; | |
908 | goto out; | |
909 | } | |
910 | EXPORT_SYMBOL_GPL(lookup_instantiate_filp); | |
911 | ||
912 | /** | |
913 | * nameidata_to_filp - convert a nameidata to an open filp. | |
914 | * @nd: pointer to nameidata | |
915 | * @flags: open flags | |
916 | * | |
917 | * Note that this function destroys the original nameidata | |
918 | */ | |
919 | struct file *nameidata_to_filp(struct nameidata *nd, int flags) | |
920 | { | |
921 | struct file *filp; | |
922 | ||
923 | /* Pick up the filp from the open intent */ | |
924 | filp = nd->intent.open.file; | |
925 | /* Has the filesystem initialised the file for us? */ | |
0f7fc9e4 | 926 | if (filp->f_path.dentry == NULL) |
4ac91378 JB |
927 | filp = __dentry_open(nd->path.dentry, nd->path.mnt, flags, filp, |
928 | NULL); | |
834f2a4a | 929 | else |
1d957f9b | 930 | path_put(&nd->path); |
834f2a4a TM |
931 | return filp; |
932 | } | |
933 | ||
6fdcc216 PS |
934 | /* |
935 | * dentry_open() will have done dput(dentry) and mntput(mnt) if it returns an | |
936 | * error. | |
937 | */ | |
a1a5b3d9 PS |
938 | struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags) |
939 | { | |
940 | int error; | |
941 | struct file *f; | |
942 | ||
322ee5b3 CH |
943 | /* |
944 | * We must always pass in a valid mount pointer. Historically | |
945 | * callers got away with not passing it, but we must enforce this at | |
946 | * the earliest possible point now to avoid strange problems deep in the | |
947 | * filesystem stack. | |
948 | */ | |
949 | if (!mnt) { | |
950 | printk(KERN_WARNING "%s called with NULL vfsmount\n", __func__); | |
951 | dump_stack(); | |
952 | return ERR_PTR(-EINVAL); | |
953 | } | |
954 | ||
a1a5b3d9 PS |
955 | error = -ENFILE; |
956 | f = get_empty_filp(); | |
6fdcc216 PS |
957 | if (f == NULL) { |
958 | dput(dentry); | |
959 | mntput(mnt); | |
a1a5b3d9 | 960 | return ERR_PTR(error); |
6fdcc216 | 961 | } |
a1a5b3d9 | 962 | |
834f2a4a | 963 | return __dentry_open(dentry, mnt, flags, f, NULL); |
a1a5b3d9 | 964 | } |
1da177e4 LT |
965 | EXPORT_SYMBOL(dentry_open); |
966 | ||
967 | /* | |
968 | * Find an empty file descriptor entry, and mark it busy. | |
969 | */ | |
4a19542e | 970 | int get_unused_fd_flags(int flags) |
1da177e4 LT |
971 | { |
972 | struct files_struct * files = current->files; | |
973 | int fd, error; | |
badf1662 | 974 | struct fdtable *fdt; |
1da177e4 LT |
975 | |
976 | error = -EMFILE; | |
977 | spin_lock(&files->file_lock); | |
978 | ||
979 | repeat: | |
badf1662 | 980 | fdt = files_fdtable(files); |
bbea9f69 | 981 | fd = find_next_zero_bit(fdt->open_fds->fds_bits, fdt->max_fds, |
0c9e63fd | 982 | files->next_fd); |
1da177e4 LT |
983 | |
984 | /* | |
985 | * N.B. For clone tasks sharing a files structure, this test | |
986 | * will limit the total number of files that can be opened. | |
987 | */ | |
988 | if (fd >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur) | |
989 | goto out; | |
990 | ||
991 | /* Do we need to expand the fd array or fd set? */ | |
992 | error = expand_files(files, fd); | |
993 | if (error < 0) | |
994 | goto out; | |
995 | ||
996 | if (error) { | |
997 | /* | |
998 | * If we needed to expand the fs array we | |
999 | * might have blocked - try again. | |
1000 | */ | |
1001 | error = -EMFILE; | |
1002 | goto repeat; | |
1003 | } | |
1004 | ||
badf1662 | 1005 | FD_SET(fd, fdt->open_fds); |
f23513e8 UD |
1006 | if (flags & O_CLOEXEC) |
1007 | FD_SET(fd, fdt->close_on_exec); | |
1008 | else | |
1009 | FD_CLR(fd, fdt->close_on_exec); | |
0c9e63fd | 1010 | files->next_fd = fd + 1; |
1da177e4 LT |
1011 | #if 1 |
1012 | /* Sanity check */ | |
badf1662 | 1013 | if (fdt->fd[fd] != NULL) { |
1da177e4 | 1014 | printk(KERN_WARNING "get_unused_fd: slot %d not NULL!\n", fd); |
badf1662 | 1015 | fdt->fd[fd] = NULL; |
1da177e4 LT |
1016 | } |
1017 | #endif | |
1018 | error = fd; | |
1019 | ||
1020 | out: | |
1021 | spin_unlock(&files->file_lock); | |
1022 | return error; | |
1023 | } | |
1024 | ||
f23513e8 UD |
1025 | int get_unused_fd(void) |
1026 | { | |
1027 | return get_unused_fd_flags(0); | |
1028 | } | |
1029 | ||
1da177e4 LT |
1030 | EXPORT_SYMBOL(get_unused_fd); |
1031 | ||
b01ec0ef | 1032 | static void __put_unused_fd(struct files_struct *files, unsigned int fd) |
1da177e4 | 1033 | { |
badf1662 DS |
1034 | struct fdtable *fdt = files_fdtable(files); |
1035 | __FD_CLR(fd, fdt->open_fds); | |
0c9e63fd ED |
1036 | if (fd < files->next_fd) |
1037 | files->next_fd = fd; | |
1da177e4 LT |
1038 | } |
1039 | ||
fc9b52cd | 1040 | void put_unused_fd(unsigned int fd) |
1da177e4 LT |
1041 | { |
1042 | struct files_struct *files = current->files; | |
1043 | spin_lock(&files->file_lock); | |
1044 | __put_unused_fd(files, fd); | |
1045 | spin_unlock(&files->file_lock); | |
1046 | } | |
1047 | ||
1048 | EXPORT_SYMBOL(put_unused_fd); | |
1049 | ||
1050 | /* | |
5590ff0d | 1051 | * Install a file pointer in the fd array. |
1da177e4 LT |
1052 | * |
1053 | * The VFS is full of places where we drop the files lock between | |
1054 | * setting the open_fds bitmap and installing the file in the file | |
1055 | * array. At any such point, we are vulnerable to a dup2() race | |
1056 | * installing a file in the array before us. We need to detect this and | |
1057 | * fput() the struct file we are about to overwrite in this case. | |
1058 | * | |
1059 | * It should never happen - if we allow dup2() do it, _really_ bad things | |
1060 | * will follow. | |
1061 | */ | |
1062 | ||
fc9b52cd | 1063 | void fd_install(unsigned int fd, struct file *file) |
1da177e4 LT |
1064 | { |
1065 | struct files_struct *files = current->files; | |
badf1662 | 1066 | struct fdtable *fdt; |
1da177e4 | 1067 | spin_lock(&files->file_lock); |
badf1662 | 1068 | fdt = files_fdtable(files); |
ab2af1f5 DS |
1069 | BUG_ON(fdt->fd[fd] != NULL); |
1070 | rcu_assign_pointer(fdt->fd[fd], file); | |
1da177e4 LT |
1071 | spin_unlock(&files->file_lock); |
1072 | } | |
1073 | ||
1074 | EXPORT_SYMBOL(fd_install); | |
1075 | ||
5590ff0d | 1076 | long do_sys_open(int dfd, const char __user *filename, int flags, int mode) |
1da177e4 | 1077 | { |
e922efc3 MS |
1078 | char *tmp = getname(filename); |
1079 | int fd = PTR_ERR(tmp); | |
1da177e4 | 1080 | |
1da177e4 | 1081 | if (!IS_ERR(tmp)) { |
f23513e8 | 1082 | fd = get_unused_fd_flags(flags); |
1da177e4 | 1083 | if (fd >= 0) { |
5590ff0d | 1084 | struct file *f = do_filp_open(dfd, tmp, flags, mode); |
fed2fc18 TN |
1085 | if (IS_ERR(f)) { |
1086 | put_unused_fd(fd); | |
1087 | fd = PTR_ERR(f); | |
1088 | } else { | |
0f7fc9e4 | 1089 | fsnotify_open(f->f_path.dentry); |
fed2fc18 TN |
1090 | fd_install(fd, f); |
1091 | } | |
1da177e4 | 1092 | } |
1da177e4 LT |
1093 | putname(tmp); |
1094 | } | |
1095 | return fd; | |
1da177e4 | 1096 | } |
e922efc3 MS |
1097 | |
1098 | asmlinkage long sys_open(const char __user *filename, int flags, int mode) | |
1099 | { | |
385910f2 LT |
1100 | long ret; |
1101 | ||
e922efc3 MS |
1102 | if (force_o_largefile()) |
1103 | flags |= O_LARGEFILE; | |
1104 | ||
385910f2 LT |
1105 | ret = do_sys_open(AT_FDCWD, filename, flags, mode); |
1106 | /* avoid REGPARM breakage on x86: */ | |
54a01510 | 1107 | asmlinkage_protect(3, ret, filename, flags, mode); |
385910f2 | 1108 | return ret; |
e922efc3 | 1109 | } |
1da177e4 | 1110 | |
5590ff0d UD |
1111 | asmlinkage long sys_openat(int dfd, const char __user *filename, int flags, |
1112 | int mode) | |
1113 | { | |
385910f2 LT |
1114 | long ret; |
1115 | ||
5590ff0d UD |
1116 | if (force_o_largefile()) |
1117 | flags |= O_LARGEFILE; | |
1118 | ||
385910f2 LT |
1119 | ret = do_sys_open(dfd, filename, flags, mode); |
1120 | /* avoid REGPARM breakage on x86: */ | |
54a01510 | 1121 | asmlinkage_protect(4, ret, dfd, filename, flags, mode); |
385910f2 | 1122 | return ret; |
5590ff0d | 1123 | } |
5590ff0d | 1124 | |
1da177e4 LT |
1125 | #ifndef __alpha__ |
1126 | ||
1127 | /* | |
1128 | * For backward compatibility? Maybe this should be moved | |
1129 | * into arch/i386 instead? | |
1130 | */ | |
1131 | asmlinkage long sys_creat(const char __user * pathname, int mode) | |
1132 | { | |
1133 | return sys_open(pathname, O_CREAT | O_WRONLY | O_TRUNC, mode); | |
1134 | } | |
1135 | ||
1136 | #endif | |
1137 | ||
1138 | /* | |
1139 | * "id" is the POSIX thread ID. We use the | |
1140 | * files pointer for this.. | |
1141 | */ | |
1142 | int filp_close(struct file *filp, fl_owner_t id) | |
1143 | { | |
45778ca8 | 1144 | int retval = 0; |
1da177e4 LT |
1145 | |
1146 | if (!file_count(filp)) { | |
1147 | printk(KERN_ERR "VFS: Close: file count is 0\n"); | |
45778ca8 | 1148 | return 0; |
1da177e4 LT |
1149 | } |
1150 | ||
45778ca8 | 1151 | if (filp->f_op && filp->f_op->flush) |
75e1fcc0 | 1152 | retval = filp->f_op->flush(filp, id); |
1da177e4 LT |
1153 | |
1154 | dnotify_flush(filp, id); | |
1155 | locks_remove_posix(filp, id); | |
1156 | fput(filp); | |
1157 | return retval; | |
1158 | } | |
1159 | ||
1160 | EXPORT_SYMBOL(filp_close); | |
1161 | ||
1162 | /* | |
1163 | * Careful here! We test whether the file pointer is NULL before | |
1164 | * releasing the fd. This ensures that one clone task can't release | |
1165 | * an fd while another clone is opening it. | |
1166 | */ | |
1167 | asmlinkage long sys_close(unsigned int fd) | |
1168 | { | |
1169 | struct file * filp; | |
1170 | struct files_struct *files = current->files; | |
badf1662 | 1171 | struct fdtable *fdt; |
ee731f4f | 1172 | int retval; |
1da177e4 LT |
1173 | |
1174 | spin_lock(&files->file_lock); | |
badf1662 DS |
1175 | fdt = files_fdtable(files); |
1176 | if (fd >= fdt->max_fds) | |
1da177e4 | 1177 | goto out_unlock; |
badf1662 | 1178 | filp = fdt->fd[fd]; |
1da177e4 LT |
1179 | if (!filp) |
1180 | goto out_unlock; | |
ab2af1f5 | 1181 | rcu_assign_pointer(fdt->fd[fd], NULL); |
badf1662 | 1182 | FD_CLR(fd, fdt->close_on_exec); |
1da177e4 LT |
1183 | __put_unused_fd(files, fd); |
1184 | spin_unlock(&files->file_lock); | |
ee731f4f EP |
1185 | retval = filp_close(filp, files); |
1186 | ||
1187 | /* can't restart close syscall because file table entry was cleared */ | |
1188 | if (unlikely(retval == -ERESTARTSYS || | |
1189 | retval == -ERESTARTNOINTR || | |
1190 | retval == -ERESTARTNOHAND || | |
1191 | retval == -ERESTART_RESTARTBLOCK)) | |
1192 | retval = -EINTR; | |
1193 | ||
1194 | return retval; | |
1da177e4 LT |
1195 | |
1196 | out_unlock: | |
1197 | spin_unlock(&files->file_lock); | |
1198 | return -EBADF; | |
1199 | } | |
1200 | ||
1201 | EXPORT_SYMBOL(sys_close); | |
1202 | ||
1203 | /* | |
1204 | * This routine simulates a hangup on the tty, to arrange that users | |
1205 | * are given clean terminals at login time. | |
1206 | */ | |
1207 | asmlinkage long sys_vhangup(void) | |
1208 | { | |
1209 | if (capable(CAP_SYS_TTY_CONFIG)) { | |
24ec839c | 1210 | /* XXX: this needs locking */ |
1da177e4 LT |
1211 | tty_vhangup(current->signal->tty); |
1212 | return 0; | |
1213 | } | |
1214 | return -EPERM; | |
1215 | } | |
1216 | ||
1217 | /* | |
1218 | * Called when an inode is about to be open. | |
1219 | * We use this to disallow opening large files on 32bit systems if | |
1220 | * the caller didn't specify O_LARGEFILE. On 64bit systems we force | |
1221 | * on this flag in sys_open. | |
1222 | */ | |
1223 | int generic_file_open(struct inode * inode, struct file * filp) | |
1224 | { | |
1225 | if (!(filp->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS) | |
a9c62a18 | 1226 | return -EOVERFLOW; |
1da177e4 LT |
1227 | return 0; |
1228 | } | |
1229 | ||
1230 | EXPORT_SYMBOL(generic_file_open); | |
1231 | ||
1232 | /* | |
1233 | * This is used by subsystems that don't want seekable | |
1234 | * file descriptors | |
1235 | */ | |
1236 | int nonseekable_open(struct inode *inode, struct file *filp) | |
1237 | { | |
1238 | filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE); | |
1239 | return 0; | |
1240 | } | |
1241 | ||
1242 | EXPORT_SYMBOL(nonseekable_open); |