]>
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> | |
9 | #include <linux/utime.h> | |
10 | #include <linux/file.h> | |
11 | #include <linux/smp_lock.h> | |
12 | #include <linux/quotaops.h> | |
0eeca283 | 13 | #include <linux/fsnotify.h> |
1da177e4 LT |
14 | #include <linux/module.h> |
15 | #include <linux/slab.h> | |
16 | #include <linux/tty.h> | |
17 | #include <linux/namei.h> | |
18 | #include <linux/backing-dev.h> | |
19 | #include <linux/security.h> | |
20 | #include <linux/mount.h> | |
21 | #include <linux/vfs.h> | |
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> |
1da177e4 LT |
28 | |
29 | #include <asm/unistd.h> | |
30 | ||
31 | int vfs_statfs(struct super_block *sb, struct kstatfs *buf) | |
32 | { | |
33 | int retval = -ENODEV; | |
34 | ||
35 | if (sb) { | |
36 | retval = -ENOSYS; | |
37 | if (sb->s_op->statfs) { | |
38 | memset(buf, 0, sizeof(*buf)); | |
39 | retval = security_sb_statfs(sb); | |
40 | if (retval) | |
41 | return retval; | |
42 | retval = sb->s_op->statfs(sb, buf); | |
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 | ||
52 | static int vfs_statfs_native(struct super_block *sb, struct statfs *buf) | |
53 | { | |
54 | struct kstatfs st; | |
55 | int retval; | |
56 | ||
57 | retval = vfs_statfs(sb, &st); | |
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 | ||
95 | static int vfs_statfs64(struct super_block *sb, struct statfs64 *buf) | |
96 | { | |
97 | struct kstatfs st; | |
98 | int retval; | |
99 | ||
100 | retval = vfs_statfs(sb, &st); | |
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; | |
130 | error = vfs_statfs_native(nd.dentry->d_inode->i_sb, &tmp); | |
131 | if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) | |
132 | error = -EFAULT; | |
133 | path_release(&nd); | |
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; | |
149 | error = vfs_statfs64(nd.dentry->d_inode->i_sb, &tmp); | |
150 | if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) | |
151 | error = -EFAULT; | |
152 | path_release(&nd); | |
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; | |
168 | error = vfs_statfs_native(file->f_dentry->d_inode->i_sb, &tmp); | |
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; | |
189 | error = vfs_statfs64(file->f_dentry->d_inode->i_sb, &tmp); | |
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 | |
1b1dcc1b | 214 | mutex_lock(&dentry->d_inode->i_mutex); |
1da177e4 | 215 | err = notify_change(dentry, &newattrs); |
1b1dcc1b | 216 | mutex_unlock(&dentry->d_inode->i_mutex); |
1da177e4 LT |
217 | return err; |
218 | } | |
219 | ||
b01ec0ef | 220 | static long do_sys_truncate(const char __user * path, loff_t length) |
1da177e4 LT |
221 | { |
222 | struct nameidata nd; | |
223 | struct inode * inode; | |
224 | int error; | |
225 | ||
226 | error = -EINVAL; | |
227 | if (length < 0) /* sorry, but loff_t says... */ | |
228 | goto out; | |
229 | ||
230 | error = user_path_walk(path, &nd); | |
231 | if (error) | |
232 | goto out; | |
233 | inode = nd.dentry->d_inode; | |
234 | ||
235 | /* For directories it's -EISDIR, for other non-regulars - -EINVAL */ | |
236 | error = -EISDIR; | |
237 | if (S_ISDIR(inode->i_mode)) | |
238 | goto dput_and_out; | |
239 | ||
240 | error = -EINVAL; | |
241 | if (!S_ISREG(inode->i_mode)) | |
242 | goto dput_and_out; | |
243 | ||
e4543edd | 244 | error = vfs_permission(&nd, MAY_WRITE); |
1da177e4 LT |
245 | if (error) |
246 | goto dput_and_out; | |
247 | ||
248 | error = -EROFS; | |
249 | if (IS_RDONLY(inode)) | |
250 | goto dput_and_out; | |
251 | ||
252 | error = -EPERM; | |
253 | if (IS_IMMUTABLE(inode) || IS_APPEND(inode)) | |
254 | goto dput_and_out; | |
255 | ||
256 | /* | |
257 | * Make sure that there are no leases. | |
258 | */ | |
259 | error = break_lease(inode, FMODE_WRITE); | |
260 | if (error) | |
261 | goto dput_and_out; | |
262 | ||
263 | error = get_write_access(inode); | |
264 | if (error) | |
265 | goto dput_and_out; | |
266 | ||
267 | error = locks_verify_truncate(inode, NULL, length); | |
268 | if (!error) { | |
269 | DQUOT_INIT(inode); | |
4a30131e | 270 | error = do_truncate(nd.dentry, length, 0, NULL); |
1da177e4 LT |
271 | } |
272 | put_write_access(inode); | |
273 | ||
274 | dput_and_out: | |
275 | path_release(&nd); | |
276 | out: | |
277 | return error; | |
278 | } | |
279 | ||
280 | asmlinkage long sys_truncate(const char __user * path, unsigned long length) | |
281 | { | |
282 | /* on 32-bit boxen it will cut the range 2^31--2^32-1 off */ | |
283 | return do_sys_truncate(path, (long)length); | |
284 | } | |
285 | ||
b01ec0ef | 286 | static long do_sys_ftruncate(unsigned int fd, loff_t length, int small) |
1da177e4 LT |
287 | { |
288 | struct inode * inode; | |
289 | struct dentry *dentry; | |
290 | struct file * file; | |
291 | int error; | |
292 | ||
293 | error = -EINVAL; | |
294 | if (length < 0) | |
295 | goto out; | |
296 | error = -EBADF; | |
297 | file = fget(fd); | |
298 | if (!file) | |
299 | goto out; | |
300 | ||
301 | /* explicitly opened as large or we are on 64-bit box */ | |
302 | if (file->f_flags & O_LARGEFILE) | |
303 | small = 0; | |
304 | ||
305 | dentry = file->f_dentry; | |
306 | inode = dentry->d_inode; | |
307 | error = -EINVAL; | |
308 | if (!S_ISREG(inode->i_mode) || !(file->f_mode & FMODE_WRITE)) | |
309 | goto out_putf; | |
310 | ||
311 | error = -EINVAL; | |
312 | /* Cannot ftruncate over 2^31 bytes without large file support */ | |
313 | if (small && length > MAX_NON_LFS) | |
314 | goto out_putf; | |
315 | ||
316 | error = -EPERM; | |
317 | if (IS_APPEND(inode)) | |
318 | goto out_putf; | |
319 | ||
320 | error = locks_verify_truncate(inode, file, length); | |
321 | if (!error) | |
4a30131e | 322 | error = do_truncate(dentry, length, 0, file); |
1da177e4 LT |
323 | out_putf: |
324 | fput(file); | |
325 | out: | |
326 | return error; | |
327 | } | |
328 | ||
329 | asmlinkage long sys_ftruncate(unsigned int fd, unsigned long length) | |
330 | { | |
331 | return do_sys_ftruncate(fd, length, 1); | |
332 | } | |
333 | ||
334 | /* LFS versions of truncate are only needed on 32 bit machines */ | |
335 | #if BITS_PER_LONG == 32 | |
336 | asmlinkage long sys_truncate64(const char __user * path, loff_t length) | |
337 | { | |
338 | return do_sys_truncate(path, length); | |
339 | } | |
340 | ||
341 | asmlinkage long sys_ftruncate64(unsigned int fd, loff_t length) | |
342 | { | |
343 | return do_sys_ftruncate(fd, length, 0); | |
344 | } | |
345 | #endif | |
346 | ||
347 | #ifdef __ARCH_WANT_SYS_UTIME | |
348 | ||
349 | /* | |
350 | * sys_utime() can be implemented in user-level using sys_utimes(). | |
351 | * Is this for backwards compatibility? If so, why not move it | |
352 | * into the appropriate arch directory (for those architectures that | |
353 | * need it). | |
354 | */ | |
355 | ||
356 | /* If times==NULL, set access and modification to current time, | |
357 | * must be owner or have write permission. | |
358 | * Else, update from *times, must be owner or super user. | |
359 | */ | |
360 | asmlinkage long sys_utime(char __user * filename, struct utimbuf __user * times) | |
361 | { | |
362 | int error; | |
363 | struct nameidata nd; | |
364 | struct inode * inode; | |
365 | struct iattr newattrs; | |
366 | ||
367 | error = user_path_walk(filename, &nd); | |
368 | if (error) | |
369 | goto out; | |
370 | inode = nd.dentry->d_inode; | |
371 | ||
372 | error = -EROFS; | |
373 | if (IS_RDONLY(inode)) | |
374 | goto dput_and_out; | |
375 | ||
376 | /* Don't worry, the checks are done in inode_change_ok() */ | |
377 | newattrs.ia_valid = ATTR_CTIME | ATTR_MTIME | ATTR_ATIME; | |
378 | if (times) { | |
379 | error = -EPERM; | |
380 | if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) | |
381 | goto dput_and_out; | |
382 | ||
383 | error = get_user(newattrs.ia_atime.tv_sec, ×->actime); | |
384 | newattrs.ia_atime.tv_nsec = 0; | |
385 | if (!error) | |
386 | error = get_user(newattrs.ia_mtime.tv_sec, ×->modtime); | |
387 | newattrs.ia_mtime.tv_nsec = 0; | |
388 | if (error) | |
389 | goto dput_and_out; | |
390 | ||
391 | newattrs.ia_valid |= ATTR_ATIME_SET | ATTR_MTIME_SET; | |
392 | } else { | |
393 | error = -EACCES; | |
394 | if (IS_IMMUTABLE(inode)) | |
395 | goto dput_and_out; | |
396 | ||
397 | if (current->fsuid != inode->i_uid && | |
e4543edd | 398 | (error = vfs_permission(&nd, MAY_WRITE)) != 0) |
1da177e4 LT |
399 | goto dput_and_out; |
400 | } | |
1b1dcc1b | 401 | mutex_lock(&inode->i_mutex); |
1da177e4 | 402 | error = notify_change(nd.dentry, &newattrs); |
1b1dcc1b | 403 | mutex_unlock(&inode->i_mutex); |
1da177e4 LT |
404 | dput_and_out: |
405 | path_release(&nd); | |
406 | out: | |
407 | return error; | |
408 | } | |
409 | ||
410 | #endif | |
411 | ||
412 | /* If times==NULL, set access and modification to current time, | |
413 | * must be owner or have write permission. | |
414 | * Else, update from *times, must be owner or super user. | |
415 | */ | |
416 | long do_utimes(char __user * filename, struct timeval * times) | |
417 | { | |
418 | int error; | |
419 | struct nameidata nd; | |
420 | struct inode * inode; | |
421 | struct iattr newattrs; | |
422 | ||
423 | error = user_path_walk(filename, &nd); | |
424 | ||
425 | if (error) | |
426 | goto out; | |
427 | inode = nd.dentry->d_inode; | |
428 | ||
429 | error = -EROFS; | |
430 | if (IS_RDONLY(inode)) | |
431 | goto dput_and_out; | |
432 | ||
433 | /* Don't worry, the checks are done in inode_change_ok() */ | |
434 | newattrs.ia_valid = ATTR_CTIME | ATTR_MTIME | ATTR_ATIME; | |
435 | if (times) { | |
436 | error = -EPERM; | |
437 | if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) | |
438 | goto dput_and_out; | |
439 | ||
440 | newattrs.ia_atime.tv_sec = times[0].tv_sec; | |
441 | newattrs.ia_atime.tv_nsec = times[0].tv_usec * 1000; | |
442 | newattrs.ia_mtime.tv_sec = times[1].tv_sec; | |
443 | newattrs.ia_mtime.tv_nsec = times[1].tv_usec * 1000; | |
444 | newattrs.ia_valid |= ATTR_ATIME_SET | ATTR_MTIME_SET; | |
445 | } else { | |
446 | error = -EACCES; | |
447 | if (IS_IMMUTABLE(inode)) | |
448 | goto dput_and_out; | |
449 | ||
450 | if (current->fsuid != inode->i_uid && | |
e4543edd | 451 | (error = vfs_permission(&nd, MAY_WRITE)) != 0) |
1da177e4 LT |
452 | goto dput_and_out; |
453 | } | |
1b1dcc1b | 454 | mutex_lock(&inode->i_mutex); |
1da177e4 | 455 | error = notify_change(nd.dentry, &newattrs); |
1b1dcc1b | 456 | mutex_unlock(&inode->i_mutex); |
1da177e4 LT |
457 | dput_and_out: |
458 | path_release(&nd); | |
459 | out: | |
460 | return error; | |
461 | } | |
462 | ||
463 | asmlinkage long sys_utimes(char __user * filename, struct timeval __user * utimes) | |
464 | { | |
465 | struct timeval times[2]; | |
466 | ||
467 | if (utimes && copy_from_user(×, utimes, sizeof(times))) | |
468 | return -EFAULT; | |
469 | return do_utimes(filename, utimes ? times : NULL); | |
470 | } | |
471 | ||
472 | ||
473 | /* | |
474 | * access() needs to use the real uid/gid, not the effective uid/gid. | |
475 | * We do this by temporarily clearing all FS-related capabilities and | |
476 | * switching the fsuid/fsgid around to the real ones. | |
477 | */ | |
478 | asmlinkage long sys_access(const char __user * filename, int mode) | |
479 | { | |
480 | struct nameidata nd; | |
481 | int old_fsuid, old_fsgid; | |
482 | kernel_cap_t old_cap; | |
483 | int res; | |
484 | ||
485 | if (mode & ~S_IRWXO) /* where's F_OK, X_OK, W_OK, R_OK? */ | |
486 | return -EINVAL; | |
487 | ||
488 | old_fsuid = current->fsuid; | |
489 | old_fsgid = current->fsgid; | |
490 | old_cap = current->cap_effective; | |
491 | ||
492 | current->fsuid = current->uid; | |
493 | current->fsgid = current->gid; | |
494 | ||
495 | /* | |
496 | * Clear the capabilities if we switch to a non-root user | |
497 | * | |
498 | * FIXME: There is a race here against sys_capset. The | |
499 | * capabilities can change yet we will restore the old | |
500 | * value below. We should hold task_capabilities_lock, | |
501 | * but we cannot because user_path_walk can sleep. | |
502 | */ | |
503 | if (current->uid) | |
504 | cap_clear(current->cap_effective); | |
505 | else | |
506 | current->cap_effective = current->cap_permitted; | |
507 | ||
508 | res = __user_walk(filename, LOOKUP_FOLLOW|LOOKUP_ACCESS, &nd); | |
509 | if (!res) { | |
e4543edd | 510 | res = vfs_permission(&nd, mode); |
1da177e4 LT |
511 | /* SuS v2 requires we report a read only fs too */ |
512 | if(!res && (mode & S_IWOTH) && IS_RDONLY(nd.dentry->d_inode) | |
513 | && !special_file(nd.dentry->d_inode->i_mode)) | |
514 | res = -EROFS; | |
515 | path_release(&nd); | |
516 | } | |
517 | ||
518 | current->fsuid = old_fsuid; | |
519 | current->fsgid = old_fsgid; | |
520 | current->cap_effective = old_cap; | |
521 | ||
522 | return res; | |
523 | } | |
524 | ||
525 | asmlinkage long sys_chdir(const char __user * filename) | |
526 | { | |
527 | struct nameidata nd; | |
528 | int error; | |
529 | ||
530 | error = __user_walk(filename, LOOKUP_FOLLOW|LOOKUP_DIRECTORY, &nd); | |
531 | if (error) | |
532 | goto out; | |
533 | ||
e4543edd | 534 | error = vfs_permission(&nd, MAY_EXEC); |
1da177e4 LT |
535 | if (error) |
536 | goto dput_and_out; | |
537 | ||
538 | set_fs_pwd(current->fs, nd.mnt, nd.dentry); | |
539 | ||
540 | dput_and_out: | |
541 | path_release(&nd); | |
542 | out: | |
543 | return error; | |
544 | } | |
545 | ||
546 | asmlinkage long sys_fchdir(unsigned int fd) | |
547 | { | |
548 | struct file *file; | |
549 | struct dentry *dentry; | |
550 | struct inode *inode; | |
551 | struct vfsmount *mnt; | |
552 | int error; | |
553 | ||
554 | error = -EBADF; | |
555 | file = fget(fd); | |
556 | if (!file) | |
557 | goto out; | |
558 | ||
559 | dentry = file->f_dentry; | |
560 | mnt = file->f_vfsmnt; | |
561 | inode = dentry->d_inode; | |
562 | ||
563 | error = -ENOTDIR; | |
564 | if (!S_ISDIR(inode->i_mode)) | |
565 | goto out_putf; | |
566 | ||
8c744fb8 | 567 | error = file_permission(file, MAY_EXEC); |
1da177e4 LT |
568 | if (!error) |
569 | set_fs_pwd(current->fs, mnt, dentry); | |
570 | out_putf: | |
571 | fput(file); | |
572 | out: | |
573 | return error; | |
574 | } | |
575 | ||
576 | asmlinkage long sys_chroot(const char __user * filename) | |
577 | { | |
578 | struct nameidata nd; | |
579 | int error; | |
580 | ||
581 | error = __user_walk(filename, LOOKUP_FOLLOW | LOOKUP_DIRECTORY | LOOKUP_NOALT, &nd); | |
582 | if (error) | |
583 | goto out; | |
584 | ||
e4543edd | 585 | error = vfs_permission(&nd, MAY_EXEC); |
1da177e4 LT |
586 | if (error) |
587 | goto dput_and_out; | |
588 | ||
589 | error = -EPERM; | |
590 | if (!capable(CAP_SYS_CHROOT)) | |
591 | goto dput_and_out; | |
592 | ||
593 | set_fs_root(current->fs, nd.mnt, nd.dentry); | |
594 | set_fs_altroot(); | |
595 | error = 0; | |
596 | dput_and_out: | |
597 | path_release(&nd); | |
598 | out: | |
599 | return error; | |
600 | } | |
601 | ||
602 | asmlinkage long sys_fchmod(unsigned int fd, mode_t mode) | |
603 | { | |
604 | struct inode * inode; | |
605 | struct dentry * dentry; | |
606 | struct file * file; | |
607 | int err = -EBADF; | |
608 | struct iattr newattrs; | |
609 | ||
610 | file = fget(fd); | |
611 | if (!file) | |
612 | goto out; | |
613 | ||
614 | dentry = file->f_dentry; | |
615 | inode = dentry->d_inode; | |
616 | ||
617 | err = -EROFS; | |
618 | if (IS_RDONLY(inode)) | |
619 | goto out_putf; | |
620 | err = -EPERM; | |
621 | if (IS_IMMUTABLE(inode) || IS_APPEND(inode)) | |
622 | goto out_putf; | |
1b1dcc1b | 623 | mutex_lock(&inode->i_mutex); |
1da177e4 LT |
624 | if (mode == (mode_t) -1) |
625 | mode = inode->i_mode; | |
626 | newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO); | |
627 | newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; | |
628 | err = notify_change(dentry, &newattrs); | |
1b1dcc1b | 629 | mutex_unlock(&inode->i_mutex); |
1da177e4 LT |
630 | |
631 | out_putf: | |
632 | fput(file); | |
633 | out: | |
634 | return err; | |
635 | } | |
636 | ||
637 | asmlinkage long sys_chmod(const char __user * filename, mode_t mode) | |
638 | { | |
639 | struct nameidata nd; | |
640 | struct inode * inode; | |
641 | int error; | |
642 | struct iattr newattrs; | |
643 | ||
644 | error = user_path_walk(filename, &nd); | |
645 | if (error) | |
646 | goto out; | |
647 | inode = nd.dentry->d_inode; | |
648 | ||
649 | error = -EROFS; | |
650 | if (IS_RDONLY(inode)) | |
651 | goto dput_and_out; | |
652 | ||
653 | error = -EPERM; | |
654 | if (IS_IMMUTABLE(inode) || IS_APPEND(inode)) | |
655 | goto dput_and_out; | |
656 | ||
1b1dcc1b | 657 | mutex_lock(&inode->i_mutex); |
1da177e4 LT |
658 | if (mode == (mode_t) -1) |
659 | mode = inode->i_mode; | |
660 | newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO); | |
661 | newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; | |
662 | error = notify_change(nd.dentry, &newattrs); | |
1b1dcc1b | 663 | mutex_unlock(&inode->i_mutex); |
1da177e4 LT |
664 | |
665 | dput_and_out: | |
666 | path_release(&nd); | |
667 | out: | |
668 | return error; | |
669 | } | |
670 | ||
671 | static int chown_common(struct dentry * dentry, uid_t user, gid_t group) | |
672 | { | |
673 | struct inode * inode; | |
674 | int error; | |
675 | struct iattr newattrs; | |
676 | ||
677 | error = -ENOENT; | |
678 | if (!(inode = dentry->d_inode)) { | |
679 | printk(KERN_ERR "chown_common: NULL inode\n"); | |
680 | goto out; | |
681 | } | |
682 | error = -EROFS; | |
683 | if (IS_RDONLY(inode)) | |
684 | goto out; | |
685 | error = -EPERM; | |
686 | if (IS_IMMUTABLE(inode) || IS_APPEND(inode)) | |
687 | goto out; | |
688 | newattrs.ia_valid = ATTR_CTIME; | |
689 | if (user != (uid_t) -1) { | |
690 | newattrs.ia_valid |= ATTR_UID; | |
691 | newattrs.ia_uid = user; | |
692 | } | |
693 | if (group != (gid_t) -1) { | |
694 | newattrs.ia_valid |= ATTR_GID; | |
695 | newattrs.ia_gid = group; | |
696 | } | |
697 | if (!S_ISDIR(inode->i_mode)) | |
698 | newattrs.ia_valid |= ATTR_KILL_SUID|ATTR_KILL_SGID; | |
1b1dcc1b | 699 | mutex_lock(&inode->i_mutex); |
1da177e4 | 700 | error = notify_change(dentry, &newattrs); |
1b1dcc1b | 701 | mutex_unlock(&inode->i_mutex); |
1da177e4 LT |
702 | out: |
703 | return error; | |
704 | } | |
705 | ||
706 | asmlinkage long sys_chown(const char __user * filename, uid_t user, gid_t group) | |
707 | { | |
708 | struct nameidata nd; | |
709 | int error; | |
710 | ||
711 | error = user_path_walk(filename, &nd); | |
712 | if (!error) { | |
713 | error = chown_common(nd.dentry, user, group); | |
714 | path_release(&nd); | |
715 | } | |
716 | return error; | |
717 | } | |
718 | ||
719 | asmlinkage long sys_lchown(const char __user * filename, uid_t user, gid_t group) | |
720 | { | |
721 | struct nameidata nd; | |
722 | int error; | |
723 | ||
724 | error = user_path_walk_link(filename, &nd); | |
725 | if (!error) { | |
726 | error = chown_common(nd.dentry, user, group); | |
727 | path_release(&nd); | |
728 | } | |
729 | return error; | |
730 | } | |
731 | ||
732 | ||
733 | asmlinkage long sys_fchown(unsigned int fd, uid_t user, gid_t group) | |
734 | { | |
735 | struct file * file; | |
736 | int error = -EBADF; | |
737 | ||
738 | file = fget(fd); | |
739 | if (file) { | |
740 | error = chown_common(file->f_dentry, user, group); | |
741 | fput(file); | |
742 | } | |
743 | return error; | |
744 | } | |
745 | ||
a1a5b3d9 | 746 | static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt, |
834f2a4a TM |
747 | int flags, struct file *f, |
748 | int (*open)(struct inode *, struct file *)) | |
1da177e4 | 749 | { |
1da177e4 LT |
750 | struct inode *inode; |
751 | int error; | |
752 | ||
1da177e4 | 753 | f->f_flags = flags; |
a1a5b3d9 PS |
754 | f->f_mode = ((flags+1) & O_ACCMODE) | FMODE_LSEEK | |
755 | FMODE_PREAD | FMODE_PWRITE; | |
1da177e4 LT |
756 | inode = dentry->d_inode; |
757 | if (f->f_mode & FMODE_WRITE) { | |
758 | error = get_write_access(inode); | |
759 | if (error) | |
760 | goto cleanup_file; | |
761 | } | |
762 | ||
763 | f->f_mapping = inode->i_mapping; | |
764 | f->f_dentry = dentry; | |
765 | f->f_vfsmnt = mnt; | |
766 | f->f_pos = 0; | |
767 | f->f_op = fops_get(inode->i_fop); | |
768 | file_move(f, &inode->i_sb->s_files); | |
769 | ||
834f2a4a TM |
770 | if (!open && f->f_op) |
771 | open = f->f_op->open; | |
772 | if (open) { | |
773 | error = open(inode, f); | |
1da177e4 LT |
774 | if (error) |
775 | goto cleanup_all; | |
776 | } | |
834f2a4a | 777 | |
1da177e4 LT |
778 | f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC); |
779 | ||
780 | file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping); | |
781 | ||
782 | /* NB: we're sure to have correct a_ops only after f_op->open */ | |
783 | if (f->f_flags & O_DIRECT) { | |
ceffc078 CO |
784 | if (!f->f_mapping->a_ops || |
785 | ((!f->f_mapping->a_ops->direct_IO) && | |
786 | (!f->f_mapping->a_ops->get_xip_page))) { | |
1da177e4 LT |
787 | fput(f); |
788 | f = ERR_PTR(-EINVAL); | |
789 | } | |
790 | } | |
791 | ||
792 | return f; | |
793 | ||
794 | cleanup_all: | |
795 | fops_put(f->f_op); | |
796 | if (f->f_mode & FMODE_WRITE) | |
797 | put_write_access(inode); | |
798 | file_kill(f); | |
799 | f->f_dentry = NULL; | |
800 | f->f_vfsmnt = NULL; | |
801 | cleanup_file: | |
802 | put_filp(f); | |
1da177e4 LT |
803 | dput(dentry); |
804 | mntput(mnt); | |
805 | return ERR_PTR(error); | |
806 | } | |
807 | ||
a1a5b3d9 PS |
808 | /* |
809 | * Note that while the flag value (low two bits) for sys_open means: | |
810 | * 00 - read-only | |
811 | * 01 - write-only | |
812 | * 10 - read-write | |
813 | * 11 - special | |
814 | * it is changed into | |
815 | * 00 - no permissions needed | |
816 | * 01 - read-permission | |
817 | * 10 - write-permission | |
818 | * 11 - read-write | |
819 | * for the internal routines (ie open_namei()/follow_link() etc). 00 is | |
820 | * used by symlinks. | |
821 | */ | |
822 | struct file *filp_open(const char * filename, int flags, int mode) | |
823 | { | |
824 | int namei_flags, error; | |
825 | struct nameidata nd; | |
a1a5b3d9 PS |
826 | |
827 | namei_flags = flags; | |
828 | if ((namei_flags+1) & O_ACCMODE) | |
829 | namei_flags++; | |
a1a5b3d9 PS |
830 | |
831 | error = open_namei(filename, namei_flags, mode, &nd); | |
832 | if (!error) | |
834f2a4a | 833 | return nameidata_to_filp(&nd, flags); |
a1a5b3d9 | 834 | |
a1a5b3d9 PS |
835 | return ERR_PTR(error); |
836 | } | |
837 | EXPORT_SYMBOL(filp_open); | |
838 | ||
834f2a4a TM |
839 | /** |
840 | * lookup_instantiate_filp - instantiates the open intent filp | |
841 | * @nd: pointer to nameidata | |
842 | * @dentry: pointer to dentry | |
843 | * @open: open callback | |
844 | * | |
845 | * Helper for filesystems that want to use lookup open intents and pass back | |
846 | * a fully instantiated struct file to the caller. | |
847 | * This function is meant to be called from within a filesystem's | |
848 | * lookup method. | |
849 | * Note that in case of error, nd->intent.open.file is destroyed, but the | |
850 | * path information remains valid. | |
851 | * If the open callback is set to NULL, then the standard f_op->open() | |
852 | * filesystem callback is substituted. | |
853 | */ | |
854 | struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry *dentry, | |
855 | int (*open)(struct inode *, struct file *)) | |
856 | { | |
857 | if (IS_ERR(nd->intent.open.file)) | |
858 | goto out; | |
859 | if (IS_ERR(dentry)) | |
860 | goto out_err; | |
861 | nd->intent.open.file = __dentry_open(dget(dentry), mntget(nd->mnt), | |
862 | nd->intent.open.flags - 1, | |
863 | nd->intent.open.file, | |
864 | open); | |
865 | out: | |
866 | return nd->intent.open.file; | |
867 | out_err: | |
868 | release_open_intent(nd); | |
869 | nd->intent.open.file = (struct file *)dentry; | |
870 | goto out; | |
871 | } | |
872 | EXPORT_SYMBOL_GPL(lookup_instantiate_filp); | |
873 | ||
874 | /** | |
875 | * nameidata_to_filp - convert a nameidata to an open filp. | |
876 | * @nd: pointer to nameidata | |
877 | * @flags: open flags | |
878 | * | |
879 | * Note that this function destroys the original nameidata | |
880 | */ | |
881 | struct file *nameidata_to_filp(struct nameidata *nd, int flags) | |
882 | { | |
883 | struct file *filp; | |
884 | ||
885 | /* Pick up the filp from the open intent */ | |
886 | filp = nd->intent.open.file; | |
887 | /* Has the filesystem initialised the file for us? */ | |
888 | if (filp->f_dentry == NULL) | |
889 | filp = __dentry_open(nd->dentry, nd->mnt, flags, filp, NULL); | |
890 | else | |
891 | path_release(nd); | |
892 | return filp; | |
893 | } | |
894 | ||
6fdcc216 PS |
895 | /* |
896 | * dentry_open() will have done dput(dentry) and mntput(mnt) if it returns an | |
897 | * error. | |
898 | */ | |
a1a5b3d9 PS |
899 | struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags) |
900 | { | |
901 | int error; | |
902 | struct file *f; | |
903 | ||
904 | error = -ENFILE; | |
905 | f = get_empty_filp(); | |
6fdcc216 PS |
906 | if (f == NULL) { |
907 | dput(dentry); | |
908 | mntput(mnt); | |
a1a5b3d9 | 909 | return ERR_PTR(error); |
6fdcc216 | 910 | } |
a1a5b3d9 | 911 | |
834f2a4a | 912 | return __dentry_open(dentry, mnt, flags, f, NULL); |
a1a5b3d9 | 913 | } |
1da177e4 LT |
914 | EXPORT_SYMBOL(dentry_open); |
915 | ||
916 | /* | |
917 | * Find an empty file descriptor entry, and mark it busy. | |
918 | */ | |
919 | int get_unused_fd(void) | |
920 | { | |
921 | struct files_struct * files = current->files; | |
922 | int fd, error; | |
badf1662 | 923 | struct fdtable *fdt; |
1da177e4 LT |
924 | |
925 | error = -EMFILE; | |
926 | spin_lock(&files->file_lock); | |
927 | ||
928 | repeat: | |
badf1662 DS |
929 | fdt = files_fdtable(files); |
930 | fd = find_next_zero_bit(fdt->open_fds->fds_bits, | |
931 | fdt->max_fdset, | |
932 | fdt->next_fd); | |
1da177e4 LT |
933 | |
934 | /* | |
935 | * N.B. For clone tasks sharing a files structure, this test | |
936 | * will limit the total number of files that can be opened. | |
937 | */ | |
938 | if (fd >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur) | |
939 | goto out; | |
940 | ||
941 | /* Do we need to expand the fd array or fd set? */ | |
942 | error = expand_files(files, fd); | |
943 | if (error < 0) | |
944 | goto out; | |
945 | ||
946 | if (error) { | |
947 | /* | |
948 | * If we needed to expand the fs array we | |
949 | * might have blocked - try again. | |
950 | */ | |
951 | error = -EMFILE; | |
952 | goto repeat; | |
953 | } | |
954 | ||
badf1662 DS |
955 | FD_SET(fd, fdt->open_fds); |
956 | FD_CLR(fd, fdt->close_on_exec); | |
957 | fdt->next_fd = fd + 1; | |
1da177e4 LT |
958 | #if 1 |
959 | /* Sanity check */ | |
badf1662 | 960 | if (fdt->fd[fd] != NULL) { |
1da177e4 | 961 | printk(KERN_WARNING "get_unused_fd: slot %d not NULL!\n", fd); |
badf1662 | 962 | fdt->fd[fd] = NULL; |
1da177e4 LT |
963 | } |
964 | #endif | |
965 | error = fd; | |
966 | ||
967 | out: | |
968 | spin_unlock(&files->file_lock); | |
969 | return error; | |
970 | } | |
971 | ||
972 | EXPORT_SYMBOL(get_unused_fd); | |
973 | ||
b01ec0ef | 974 | static void __put_unused_fd(struct files_struct *files, unsigned int fd) |
1da177e4 | 975 | { |
badf1662 DS |
976 | struct fdtable *fdt = files_fdtable(files); |
977 | __FD_CLR(fd, fdt->open_fds); | |
978 | if (fd < fdt->next_fd) | |
979 | fdt->next_fd = fd; | |
1da177e4 LT |
980 | } |
981 | ||
982 | void fastcall put_unused_fd(unsigned int fd) | |
983 | { | |
984 | struct files_struct *files = current->files; | |
985 | spin_lock(&files->file_lock); | |
986 | __put_unused_fd(files, fd); | |
987 | spin_unlock(&files->file_lock); | |
988 | } | |
989 | ||
990 | EXPORT_SYMBOL(put_unused_fd); | |
991 | ||
992 | /* | |
993 | * Install a file pointer in the fd array. | |
994 | * | |
995 | * The VFS is full of places where we drop the files lock between | |
996 | * setting the open_fds bitmap and installing the file in the file | |
997 | * array. At any such point, we are vulnerable to a dup2() race | |
998 | * installing a file in the array before us. We need to detect this and | |
999 | * fput() the struct file we are about to overwrite in this case. | |
1000 | * | |
1001 | * It should never happen - if we allow dup2() do it, _really_ bad things | |
1002 | * will follow. | |
1003 | */ | |
1004 | ||
1005 | void fastcall fd_install(unsigned int fd, struct file * file) | |
1006 | { | |
1007 | struct files_struct *files = current->files; | |
badf1662 | 1008 | struct fdtable *fdt; |
1da177e4 | 1009 | spin_lock(&files->file_lock); |
badf1662 | 1010 | fdt = files_fdtable(files); |
ab2af1f5 DS |
1011 | BUG_ON(fdt->fd[fd] != NULL); |
1012 | rcu_assign_pointer(fdt->fd[fd], file); | |
1da177e4 LT |
1013 | spin_unlock(&files->file_lock); |
1014 | } | |
1015 | ||
1016 | EXPORT_SYMBOL(fd_install); | |
1017 | ||
e922efc3 | 1018 | long do_sys_open(const char __user *filename, int flags, int mode) |
1da177e4 | 1019 | { |
e922efc3 MS |
1020 | char *tmp = getname(filename); |
1021 | int fd = PTR_ERR(tmp); | |
1da177e4 | 1022 | |
1da177e4 LT |
1023 | if (!IS_ERR(tmp)) { |
1024 | fd = get_unused_fd(); | |
1025 | if (fd >= 0) { | |
1026 | struct file *f = filp_open(tmp, flags, mode); | |
fed2fc18 TN |
1027 | if (IS_ERR(f)) { |
1028 | put_unused_fd(fd); | |
1029 | fd = PTR_ERR(f); | |
1030 | } else { | |
0eeca283 | 1031 | fsnotify_open(f->f_dentry); |
fed2fc18 TN |
1032 | fd_install(fd, f); |
1033 | } | |
1da177e4 | 1034 | } |
1da177e4 LT |
1035 | putname(tmp); |
1036 | } | |
1037 | return fd; | |
1da177e4 | 1038 | } |
e922efc3 MS |
1039 | |
1040 | asmlinkage long sys_open(const char __user *filename, int flags, int mode) | |
1041 | { | |
1042 | if (force_o_largefile()) | |
1043 | flags |= O_LARGEFILE; | |
1044 | ||
1045 | return do_sys_open(filename, flags, mode); | |
1046 | } | |
1da177e4 LT |
1047 | EXPORT_SYMBOL_GPL(sys_open); |
1048 | ||
1049 | #ifndef __alpha__ | |
1050 | ||
1051 | /* | |
1052 | * For backward compatibility? Maybe this should be moved | |
1053 | * into arch/i386 instead? | |
1054 | */ | |
1055 | asmlinkage long sys_creat(const char __user * pathname, int mode) | |
1056 | { | |
1057 | return sys_open(pathname, O_CREAT | O_WRONLY | O_TRUNC, mode); | |
1058 | } | |
1059 | ||
1060 | #endif | |
1061 | ||
1062 | /* | |
1063 | * "id" is the POSIX thread ID. We use the | |
1064 | * files pointer for this.. | |
1065 | */ | |
1066 | int filp_close(struct file *filp, fl_owner_t id) | |
1067 | { | |
45778ca8 | 1068 | int retval = 0; |
1da177e4 LT |
1069 | |
1070 | if (!file_count(filp)) { | |
1071 | printk(KERN_ERR "VFS: Close: file count is 0\n"); | |
45778ca8 | 1072 | return 0; |
1da177e4 LT |
1073 | } |
1074 | ||
45778ca8 CL |
1075 | if (filp->f_op && filp->f_op->flush) |
1076 | retval = filp->f_op->flush(filp); | |
1da177e4 LT |
1077 | |
1078 | dnotify_flush(filp, id); | |
1079 | locks_remove_posix(filp, id); | |
1080 | fput(filp); | |
1081 | return retval; | |
1082 | } | |
1083 | ||
1084 | EXPORT_SYMBOL(filp_close); | |
1085 | ||
1086 | /* | |
1087 | * Careful here! We test whether the file pointer is NULL before | |
1088 | * releasing the fd. This ensures that one clone task can't release | |
1089 | * an fd while another clone is opening it. | |
1090 | */ | |
1091 | asmlinkage long sys_close(unsigned int fd) | |
1092 | { | |
1093 | struct file * filp; | |
1094 | struct files_struct *files = current->files; | |
badf1662 | 1095 | struct fdtable *fdt; |
1da177e4 LT |
1096 | |
1097 | spin_lock(&files->file_lock); | |
badf1662 DS |
1098 | fdt = files_fdtable(files); |
1099 | if (fd >= fdt->max_fds) | |
1da177e4 | 1100 | goto out_unlock; |
badf1662 | 1101 | filp = fdt->fd[fd]; |
1da177e4 LT |
1102 | if (!filp) |
1103 | goto out_unlock; | |
ab2af1f5 | 1104 | rcu_assign_pointer(fdt->fd[fd], NULL); |
badf1662 | 1105 | FD_CLR(fd, fdt->close_on_exec); |
1da177e4 LT |
1106 | __put_unused_fd(files, fd); |
1107 | spin_unlock(&files->file_lock); | |
1108 | return filp_close(filp, files); | |
1109 | ||
1110 | out_unlock: | |
1111 | spin_unlock(&files->file_lock); | |
1112 | return -EBADF; | |
1113 | } | |
1114 | ||
1115 | EXPORT_SYMBOL(sys_close); | |
1116 | ||
1117 | /* | |
1118 | * This routine simulates a hangup on the tty, to arrange that users | |
1119 | * are given clean terminals at login time. | |
1120 | */ | |
1121 | asmlinkage long sys_vhangup(void) | |
1122 | { | |
1123 | if (capable(CAP_SYS_TTY_CONFIG)) { | |
1124 | tty_vhangup(current->signal->tty); | |
1125 | return 0; | |
1126 | } | |
1127 | return -EPERM; | |
1128 | } | |
1129 | ||
1130 | /* | |
1131 | * Called when an inode is about to be open. | |
1132 | * We use this to disallow opening large files on 32bit systems if | |
1133 | * the caller didn't specify O_LARGEFILE. On 64bit systems we force | |
1134 | * on this flag in sys_open. | |
1135 | */ | |
1136 | int generic_file_open(struct inode * inode, struct file * filp) | |
1137 | { | |
1138 | if (!(filp->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS) | |
1139 | return -EFBIG; | |
1140 | return 0; | |
1141 | } | |
1142 | ||
1143 | EXPORT_SYMBOL(generic_file_open); | |
1144 | ||
1145 | /* | |
1146 | * This is used by subsystems that don't want seekable | |
1147 | * file descriptors | |
1148 | */ | |
1149 | int nonseekable_open(struct inode *inode, struct file *filp) | |
1150 | { | |
1151 | filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE); | |
1152 | return 0; | |
1153 | } | |
1154 | ||
1155 | EXPORT_SYMBOL(nonseekable_open); |