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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 LT |
9 | #include <linux/file.h> |
10 | #include <linux/smp_lock.h> | |
11 | #include <linux/quotaops.h> | |
0eeca283 | 12 | #include <linux/fsnotify.h> |
1da177e4 LT |
13 | #include <linux/module.h> |
14 | #include <linux/slab.h> | |
15 | #include <linux/tty.h> | |
16 | #include <linux/namei.h> | |
17 | #include <linux/backing-dev.h> | |
16f7e0fe | 18 | #include <linux/capability.h> |
1da177e4 LT |
19 | #include <linux/security.h> |
20 | #include <linux/mount.h> | |
21 | #include <linux/vfs.h> | |
5590ff0d | 22 | #include <linux/fcntl.h> |
1da177e4 LT |
23 | #include <asm/uaccess.h> |
24 | #include <linux/fs.h> | |
ef3daeda | 25 | #include <linux/personality.h> |
1da177e4 LT |
26 | #include <linux/pagemap.h> |
27 | #include <linux/syscalls.h> | |
ab2af1f5 | 28 | #include <linux/rcupdate.h> |
73241ccc | 29 | #include <linux/audit.h> |
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; | |
726c3342 | 130 | error = vfs_statfs_native(nd.dentry, &tmp); |
1da177e4 LT |
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; | |
726c3342 | 149 | error = vfs_statfs64(nd.dentry, &tmp); |
1da177e4 LT |
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; | |
726c3342 | 168 | error = vfs_statfs_native(file->f_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; | |
726c3342 | 189 | error = vfs_statfs64(file->f_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 | |
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) | |
6e656be8 | 322 | error = do_truncate(dentry, length, ATTR_MTIME|ATTR_CTIME, 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 | { | |
0a489cb3 | 331 | long ret = do_sys_ftruncate(fd, length, 1); |
385910f2 | 332 | /* avoid REGPARM breakage on x86: */ |
0a489cb3 LT |
333 | prevent_tail_call(ret); |
334 | return ret; | |
1da177e4 LT |
335 | } |
336 | ||
337 | /* LFS versions of truncate are only needed on 32 bit machines */ | |
338 | #if BITS_PER_LONG == 32 | |
339 | asmlinkage long sys_truncate64(const char __user * path, loff_t length) | |
340 | { | |
341 | return do_sys_truncate(path, length); | |
342 | } | |
343 | ||
344 | asmlinkage long sys_ftruncate64(unsigned int fd, loff_t length) | |
345 | { | |
0a489cb3 | 346 | long ret = do_sys_ftruncate(fd, length, 0); |
385910f2 | 347 | /* avoid REGPARM breakage on x86: */ |
0a489cb3 LT |
348 | prevent_tail_call(ret); |
349 | return ret; | |
1da177e4 LT |
350 | } |
351 | #endif | |
352 | ||
1da177e4 LT |
353 | /* |
354 | * access() needs to use the real uid/gid, not the effective uid/gid. | |
355 | * We do this by temporarily clearing all FS-related capabilities and | |
356 | * switching the fsuid/fsgid around to the real ones. | |
357 | */ | |
5590ff0d | 358 | asmlinkage long sys_faccessat(int dfd, const char __user *filename, int mode) |
1da177e4 LT |
359 | { |
360 | struct nameidata nd; | |
361 | int old_fsuid, old_fsgid; | |
362 | kernel_cap_t old_cap; | |
363 | int res; | |
364 | ||
365 | if (mode & ~S_IRWXO) /* where's F_OK, X_OK, W_OK, R_OK? */ | |
366 | return -EINVAL; | |
367 | ||
368 | old_fsuid = current->fsuid; | |
369 | old_fsgid = current->fsgid; | |
370 | old_cap = current->cap_effective; | |
371 | ||
372 | current->fsuid = current->uid; | |
373 | current->fsgid = current->gid; | |
374 | ||
375 | /* | |
376 | * Clear the capabilities if we switch to a non-root user | |
377 | * | |
378 | * FIXME: There is a race here against sys_capset. The | |
379 | * capabilities can change yet we will restore the old | |
380 | * value below. We should hold task_capabilities_lock, | |
381 | * but we cannot because user_path_walk can sleep. | |
382 | */ | |
383 | if (current->uid) | |
384 | cap_clear(current->cap_effective); | |
385 | else | |
386 | current->cap_effective = current->cap_permitted; | |
387 | ||
5590ff0d | 388 | res = __user_walk_fd(dfd, filename, LOOKUP_FOLLOW|LOOKUP_ACCESS, &nd); |
6902d925 DH |
389 | if (res) |
390 | goto out; | |
391 | ||
392 | res = vfs_permission(&nd, mode); | |
393 | /* SuS v2 requires we report a read only fs too */ | |
394 | if(res || !(mode & S_IWOTH) || | |
395 | special_file(nd.dentry->d_inode->i_mode)) | |
396 | goto out_path_release; | |
397 | ||
398 | if(IS_RDONLY(nd.dentry->d_inode)) | |
399 | res = -EROFS; | |
1da177e4 | 400 | |
6902d925 DH |
401 | out_path_release: |
402 | path_release(&nd); | |
403 | out: | |
1da177e4 LT |
404 | current->fsuid = old_fsuid; |
405 | current->fsgid = old_fsgid; | |
406 | current->cap_effective = old_cap; | |
407 | ||
408 | return res; | |
409 | } | |
410 | ||
5590ff0d UD |
411 | asmlinkage long sys_access(const char __user *filename, int mode) |
412 | { | |
413 | return sys_faccessat(AT_FDCWD, filename, mode); | |
414 | } | |
415 | ||
1da177e4 LT |
416 | asmlinkage long sys_chdir(const char __user * filename) |
417 | { | |
418 | struct nameidata nd; | |
419 | int error; | |
420 | ||
650a8983 MS |
421 | error = __user_walk(filename, |
422 | LOOKUP_FOLLOW|LOOKUP_DIRECTORY|LOOKUP_CHDIR, &nd); | |
1da177e4 LT |
423 | if (error) |
424 | goto out; | |
425 | ||
e4543edd | 426 | error = vfs_permission(&nd, MAY_EXEC); |
1da177e4 LT |
427 | if (error) |
428 | goto dput_and_out; | |
429 | ||
430 | set_fs_pwd(current->fs, nd.mnt, nd.dentry); | |
431 | ||
432 | dput_and_out: | |
433 | path_release(&nd); | |
434 | out: | |
435 | return error; | |
436 | } | |
437 | ||
438 | asmlinkage long sys_fchdir(unsigned int fd) | |
439 | { | |
440 | struct file *file; | |
441 | struct dentry *dentry; | |
442 | struct inode *inode; | |
443 | struct vfsmount *mnt; | |
444 | int error; | |
445 | ||
446 | error = -EBADF; | |
447 | file = fget(fd); | |
448 | if (!file) | |
449 | goto out; | |
450 | ||
451 | dentry = file->f_dentry; | |
452 | mnt = file->f_vfsmnt; | |
453 | inode = dentry->d_inode; | |
454 | ||
455 | error = -ENOTDIR; | |
456 | if (!S_ISDIR(inode->i_mode)) | |
457 | goto out_putf; | |
458 | ||
8c744fb8 | 459 | error = file_permission(file, MAY_EXEC); |
1da177e4 LT |
460 | if (!error) |
461 | set_fs_pwd(current->fs, mnt, dentry); | |
462 | out_putf: | |
463 | fput(file); | |
464 | out: | |
465 | return error; | |
466 | } | |
467 | ||
468 | asmlinkage long sys_chroot(const char __user * filename) | |
469 | { | |
470 | struct nameidata nd; | |
471 | int error; | |
472 | ||
473 | error = __user_walk(filename, LOOKUP_FOLLOW | LOOKUP_DIRECTORY | LOOKUP_NOALT, &nd); | |
474 | if (error) | |
475 | goto out; | |
476 | ||
e4543edd | 477 | error = vfs_permission(&nd, MAY_EXEC); |
1da177e4 LT |
478 | if (error) |
479 | goto dput_and_out; | |
480 | ||
481 | error = -EPERM; | |
482 | if (!capable(CAP_SYS_CHROOT)) | |
483 | goto dput_and_out; | |
484 | ||
485 | set_fs_root(current->fs, nd.mnt, nd.dentry); | |
486 | set_fs_altroot(); | |
487 | error = 0; | |
488 | dput_and_out: | |
489 | path_release(&nd); | |
490 | out: | |
491 | return error; | |
492 | } | |
493 | ||
494 | asmlinkage long sys_fchmod(unsigned int fd, mode_t mode) | |
495 | { | |
496 | struct inode * inode; | |
497 | struct dentry * dentry; | |
498 | struct file * file; | |
499 | int err = -EBADF; | |
500 | struct iattr newattrs; | |
501 | ||
502 | file = fget(fd); | |
503 | if (!file) | |
504 | goto out; | |
505 | ||
506 | dentry = file->f_dentry; | |
507 | inode = dentry->d_inode; | |
508 | ||
9c937dcc | 509 | audit_inode(NULL, inode); |
73241ccc | 510 | |
1da177e4 LT |
511 | err = -EROFS; |
512 | if (IS_RDONLY(inode)) | |
513 | goto out_putf; | |
514 | err = -EPERM; | |
515 | if (IS_IMMUTABLE(inode) || IS_APPEND(inode)) | |
516 | goto out_putf; | |
1b1dcc1b | 517 | mutex_lock(&inode->i_mutex); |
1da177e4 LT |
518 | if (mode == (mode_t) -1) |
519 | mode = inode->i_mode; | |
520 | newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO); | |
521 | newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; | |
522 | err = notify_change(dentry, &newattrs); | |
1b1dcc1b | 523 | mutex_unlock(&inode->i_mutex); |
1da177e4 LT |
524 | |
525 | out_putf: | |
526 | fput(file); | |
527 | out: | |
528 | return err; | |
529 | } | |
530 | ||
5590ff0d UD |
531 | asmlinkage long sys_fchmodat(int dfd, const char __user *filename, |
532 | mode_t mode) | |
1da177e4 LT |
533 | { |
534 | struct nameidata nd; | |
535 | struct inode * inode; | |
536 | int error; | |
537 | struct iattr newattrs; | |
538 | ||
5590ff0d | 539 | error = __user_walk_fd(dfd, filename, LOOKUP_FOLLOW, &nd); |
1da177e4 LT |
540 | if (error) |
541 | goto out; | |
542 | inode = nd.dentry->d_inode; | |
543 | ||
544 | error = -EROFS; | |
545 | if (IS_RDONLY(inode)) | |
546 | goto dput_and_out; | |
547 | ||
548 | error = -EPERM; | |
549 | if (IS_IMMUTABLE(inode) || IS_APPEND(inode)) | |
550 | goto dput_and_out; | |
551 | ||
1b1dcc1b | 552 | mutex_lock(&inode->i_mutex); |
1da177e4 LT |
553 | if (mode == (mode_t) -1) |
554 | mode = inode->i_mode; | |
555 | newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO); | |
556 | newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; | |
557 | error = notify_change(nd.dentry, &newattrs); | |
1b1dcc1b | 558 | mutex_unlock(&inode->i_mutex); |
1da177e4 LT |
559 | |
560 | dput_and_out: | |
561 | path_release(&nd); | |
562 | out: | |
563 | return error; | |
564 | } | |
565 | ||
5590ff0d UD |
566 | asmlinkage long sys_chmod(const char __user *filename, mode_t mode) |
567 | { | |
568 | return sys_fchmodat(AT_FDCWD, filename, mode); | |
569 | } | |
570 | ||
1da177e4 LT |
571 | static int chown_common(struct dentry * dentry, uid_t user, gid_t group) |
572 | { | |
573 | struct inode * inode; | |
574 | int error; | |
575 | struct iattr newattrs; | |
576 | ||
577 | error = -ENOENT; | |
578 | if (!(inode = dentry->d_inode)) { | |
579 | printk(KERN_ERR "chown_common: NULL inode\n"); | |
580 | goto out; | |
581 | } | |
582 | error = -EROFS; | |
583 | if (IS_RDONLY(inode)) | |
584 | goto out; | |
585 | error = -EPERM; | |
586 | if (IS_IMMUTABLE(inode) || IS_APPEND(inode)) | |
587 | goto out; | |
588 | newattrs.ia_valid = ATTR_CTIME; | |
589 | if (user != (uid_t) -1) { | |
590 | newattrs.ia_valid |= ATTR_UID; | |
591 | newattrs.ia_uid = user; | |
592 | } | |
593 | if (group != (gid_t) -1) { | |
594 | newattrs.ia_valid |= ATTR_GID; | |
595 | newattrs.ia_gid = group; | |
596 | } | |
597 | if (!S_ISDIR(inode->i_mode)) | |
598 | newattrs.ia_valid |= ATTR_KILL_SUID|ATTR_KILL_SGID; | |
1b1dcc1b | 599 | mutex_lock(&inode->i_mutex); |
1da177e4 | 600 | error = notify_change(dentry, &newattrs); |
1b1dcc1b | 601 | mutex_unlock(&inode->i_mutex); |
1da177e4 LT |
602 | out: |
603 | return error; | |
604 | } | |
605 | ||
606 | asmlinkage long sys_chown(const char __user * filename, uid_t user, gid_t group) | |
607 | { | |
608 | struct nameidata nd; | |
609 | int error; | |
610 | ||
611 | error = user_path_walk(filename, &nd); | |
6902d925 DH |
612 | if (error) |
613 | goto out; | |
614 | error = chown_common(nd.dentry, user, group); | |
615 | path_release(&nd); | |
616 | out: | |
1da177e4 LT |
617 | return error; |
618 | } | |
619 | ||
5590ff0d UD |
620 | asmlinkage long sys_fchownat(int dfd, const char __user *filename, uid_t user, |
621 | gid_t group, int flag) | |
622 | { | |
623 | struct nameidata nd; | |
624 | int error = -EINVAL; | |
625 | int follow; | |
626 | ||
627 | if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0) | |
628 | goto out; | |
629 | ||
630 | follow = (flag & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW; | |
631 | error = __user_walk_fd(dfd, filename, follow, &nd); | |
6902d925 DH |
632 | if (error) |
633 | goto out; | |
634 | error = chown_common(nd.dentry, user, group); | |
635 | path_release(&nd); | |
5590ff0d UD |
636 | out: |
637 | return error; | |
638 | } | |
639 | ||
1da177e4 LT |
640 | asmlinkage long sys_lchown(const char __user * filename, uid_t user, gid_t group) |
641 | { | |
642 | struct nameidata nd; | |
643 | int error; | |
644 | ||
645 | error = user_path_walk_link(filename, &nd); | |
6902d925 DH |
646 | if (error) |
647 | goto out; | |
648 | error = chown_common(nd.dentry, user, group); | |
649 | path_release(&nd); | |
650 | out: | |
1da177e4 LT |
651 | return error; |
652 | } | |
653 | ||
654 | ||
655 | asmlinkage long sys_fchown(unsigned int fd, uid_t user, gid_t group) | |
656 | { | |
657 | struct file * file; | |
658 | int error = -EBADF; | |
6902d925 | 659 | struct dentry * dentry; |
1da177e4 LT |
660 | |
661 | file = fget(fd); | |
6902d925 DH |
662 | if (!file) |
663 | goto out; | |
664 | ||
665 | dentry = file->f_dentry; | |
666 | audit_inode(NULL, dentry->d_inode); | |
667 | error = chown_common(dentry, user, group); | |
668 | fput(file); | |
669 | out: | |
1da177e4 LT |
670 | return error; |
671 | } | |
672 | ||
a1a5b3d9 | 673 | static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt, |
834f2a4a TM |
674 | int flags, struct file *f, |
675 | int (*open)(struct inode *, struct file *)) | |
1da177e4 | 676 | { |
1da177e4 LT |
677 | struct inode *inode; |
678 | int error; | |
679 | ||
1da177e4 | 680 | f->f_flags = flags; |
a1a5b3d9 PS |
681 | f->f_mode = ((flags+1) & O_ACCMODE) | FMODE_LSEEK | |
682 | FMODE_PREAD | FMODE_PWRITE; | |
1da177e4 LT |
683 | inode = dentry->d_inode; |
684 | if (f->f_mode & FMODE_WRITE) { | |
685 | error = get_write_access(inode); | |
686 | if (error) | |
687 | goto cleanup_file; | |
688 | } | |
689 | ||
690 | f->f_mapping = inode->i_mapping; | |
691 | f->f_dentry = dentry; | |
692 | f->f_vfsmnt = mnt; | |
693 | f->f_pos = 0; | |
694 | f->f_op = fops_get(inode->i_fop); | |
695 | file_move(f, &inode->i_sb->s_files); | |
696 | ||
834f2a4a TM |
697 | if (!open && f->f_op) |
698 | open = f->f_op->open; | |
699 | if (open) { | |
700 | error = open(inode, f); | |
1da177e4 LT |
701 | if (error) |
702 | goto cleanup_all; | |
703 | } | |
834f2a4a | 704 | |
1da177e4 LT |
705 | f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC); |
706 | ||
707 | file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping); | |
708 | ||
709 | /* NB: we're sure to have correct a_ops only after f_op->open */ | |
710 | if (f->f_flags & O_DIRECT) { | |
ceffc078 CO |
711 | if (!f->f_mapping->a_ops || |
712 | ((!f->f_mapping->a_ops->direct_IO) && | |
713 | (!f->f_mapping->a_ops->get_xip_page))) { | |
1da177e4 LT |
714 | fput(f); |
715 | f = ERR_PTR(-EINVAL); | |
716 | } | |
717 | } | |
718 | ||
719 | return f; | |
720 | ||
721 | cleanup_all: | |
722 | fops_put(f->f_op); | |
723 | if (f->f_mode & FMODE_WRITE) | |
724 | put_write_access(inode); | |
725 | file_kill(f); | |
726 | f->f_dentry = NULL; | |
727 | f->f_vfsmnt = NULL; | |
728 | cleanup_file: | |
729 | put_filp(f); | |
1da177e4 LT |
730 | dput(dentry); |
731 | mntput(mnt); | |
732 | return ERR_PTR(error); | |
733 | } | |
734 | ||
a1a5b3d9 PS |
735 | /* |
736 | * Note that while the flag value (low two bits) for sys_open means: | |
737 | * 00 - read-only | |
738 | * 01 - write-only | |
739 | * 10 - read-write | |
740 | * 11 - special | |
741 | * it is changed into | |
742 | * 00 - no permissions needed | |
743 | * 01 - read-permission | |
744 | * 10 - write-permission | |
745 | * 11 - read-write | |
746 | * for the internal routines (ie open_namei()/follow_link() etc). 00 is | |
747 | * used by symlinks. | |
748 | */ | |
5590ff0d UD |
749 | static struct file *do_filp_open(int dfd, const char *filename, int flags, |
750 | int mode) | |
a1a5b3d9 PS |
751 | { |
752 | int namei_flags, error; | |
753 | struct nameidata nd; | |
a1a5b3d9 PS |
754 | |
755 | namei_flags = flags; | |
756 | if ((namei_flags+1) & O_ACCMODE) | |
757 | namei_flags++; | |
a1a5b3d9 | 758 | |
5590ff0d | 759 | error = open_namei(dfd, filename, namei_flags, mode, &nd); |
a1a5b3d9 | 760 | if (!error) |
834f2a4a | 761 | return nameidata_to_filp(&nd, flags); |
a1a5b3d9 | 762 | |
a1a5b3d9 PS |
763 | return ERR_PTR(error); |
764 | } | |
5590ff0d UD |
765 | |
766 | struct file *filp_open(const char *filename, int flags, int mode) | |
767 | { | |
768 | return do_filp_open(AT_FDCWD, filename, flags, mode); | |
769 | } | |
a1a5b3d9 PS |
770 | EXPORT_SYMBOL(filp_open); |
771 | ||
834f2a4a TM |
772 | /** |
773 | * lookup_instantiate_filp - instantiates the open intent filp | |
774 | * @nd: pointer to nameidata | |
775 | * @dentry: pointer to dentry | |
776 | * @open: open callback | |
777 | * | |
778 | * Helper for filesystems that want to use lookup open intents and pass back | |
779 | * a fully instantiated struct file to the caller. | |
780 | * This function is meant to be called from within a filesystem's | |
781 | * lookup method. | |
9a56c213 OD |
782 | * Beware of calling it for non-regular files! Those ->open methods might block |
783 | * (e.g. in fifo_open), leaving you with parent locked (and in case of fifo, | |
784 | * leading to a deadlock, as nobody can open that fifo anymore, because | |
785 | * another process to open fifo will block on locked parent when doing lookup). | |
834f2a4a TM |
786 | * Note that in case of error, nd->intent.open.file is destroyed, but the |
787 | * path information remains valid. | |
788 | * If the open callback is set to NULL, then the standard f_op->open() | |
789 | * filesystem callback is substituted. | |
790 | */ | |
791 | struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry *dentry, | |
792 | int (*open)(struct inode *, struct file *)) | |
793 | { | |
794 | if (IS_ERR(nd->intent.open.file)) | |
795 | goto out; | |
796 | if (IS_ERR(dentry)) | |
797 | goto out_err; | |
798 | nd->intent.open.file = __dentry_open(dget(dentry), mntget(nd->mnt), | |
799 | nd->intent.open.flags - 1, | |
800 | nd->intent.open.file, | |
801 | open); | |
802 | out: | |
803 | return nd->intent.open.file; | |
804 | out_err: | |
805 | release_open_intent(nd); | |
806 | nd->intent.open.file = (struct file *)dentry; | |
807 | goto out; | |
808 | } | |
809 | EXPORT_SYMBOL_GPL(lookup_instantiate_filp); | |
810 | ||
811 | /** | |
812 | * nameidata_to_filp - convert a nameidata to an open filp. | |
813 | * @nd: pointer to nameidata | |
814 | * @flags: open flags | |
815 | * | |
816 | * Note that this function destroys the original nameidata | |
817 | */ | |
818 | struct file *nameidata_to_filp(struct nameidata *nd, int flags) | |
819 | { | |
820 | struct file *filp; | |
821 | ||
822 | /* Pick up the filp from the open intent */ | |
823 | filp = nd->intent.open.file; | |
824 | /* Has the filesystem initialised the file for us? */ | |
825 | if (filp->f_dentry == NULL) | |
826 | filp = __dentry_open(nd->dentry, nd->mnt, flags, filp, NULL); | |
827 | else | |
828 | path_release(nd); | |
829 | return filp; | |
830 | } | |
831 | ||
6fdcc216 PS |
832 | /* |
833 | * dentry_open() will have done dput(dentry) and mntput(mnt) if it returns an | |
834 | * error. | |
835 | */ | |
a1a5b3d9 PS |
836 | struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags) |
837 | { | |
838 | int error; | |
839 | struct file *f; | |
840 | ||
841 | error = -ENFILE; | |
842 | f = get_empty_filp(); | |
6fdcc216 PS |
843 | if (f == NULL) { |
844 | dput(dentry); | |
845 | mntput(mnt); | |
a1a5b3d9 | 846 | return ERR_PTR(error); |
6fdcc216 | 847 | } |
a1a5b3d9 | 848 | |
834f2a4a | 849 | return __dentry_open(dentry, mnt, flags, f, NULL); |
a1a5b3d9 | 850 | } |
1da177e4 LT |
851 | EXPORT_SYMBOL(dentry_open); |
852 | ||
853 | /* | |
854 | * Find an empty file descriptor entry, and mark it busy. | |
855 | */ | |
856 | int get_unused_fd(void) | |
857 | { | |
858 | struct files_struct * files = current->files; | |
859 | int fd, error; | |
badf1662 | 860 | struct fdtable *fdt; |
1da177e4 LT |
861 | |
862 | error = -EMFILE; | |
863 | spin_lock(&files->file_lock); | |
864 | ||
865 | repeat: | |
badf1662 DS |
866 | fdt = files_fdtable(files); |
867 | fd = find_next_zero_bit(fdt->open_fds->fds_bits, | |
868 | fdt->max_fdset, | |
0c9e63fd | 869 | files->next_fd); |
1da177e4 LT |
870 | |
871 | /* | |
872 | * N.B. For clone tasks sharing a files structure, this test | |
873 | * will limit the total number of files that can be opened. | |
874 | */ | |
875 | if (fd >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur) | |
876 | goto out; | |
877 | ||
878 | /* Do we need to expand the fd array or fd set? */ | |
879 | error = expand_files(files, fd); | |
880 | if (error < 0) | |
881 | goto out; | |
882 | ||
883 | if (error) { | |
884 | /* | |
885 | * If we needed to expand the fs array we | |
886 | * might have blocked - try again. | |
887 | */ | |
888 | error = -EMFILE; | |
889 | goto repeat; | |
890 | } | |
891 | ||
badf1662 DS |
892 | FD_SET(fd, fdt->open_fds); |
893 | FD_CLR(fd, fdt->close_on_exec); | |
0c9e63fd | 894 | files->next_fd = fd + 1; |
1da177e4 LT |
895 | #if 1 |
896 | /* Sanity check */ | |
badf1662 | 897 | if (fdt->fd[fd] != NULL) { |
1da177e4 | 898 | printk(KERN_WARNING "get_unused_fd: slot %d not NULL!\n", fd); |
badf1662 | 899 | fdt->fd[fd] = NULL; |
1da177e4 LT |
900 | } |
901 | #endif | |
902 | error = fd; | |
903 | ||
904 | out: | |
905 | spin_unlock(&files->file_lock); | |
906 | return error; | |
907 | } | |
908 | ||
909 | EXPORT_SYMBOL(get_unused_fd); | |
910 | ||
b01ec0ef | 911 | static void __put_unused_fd(struct files_struct *files, unsigned int fd) |
1da177e4 | 912 | { |
badf1662 DS |
913 | struct fdtable *fdt = files_fdtable(files); |
914 | __FD_CLR(fd, fdt->open_fds); | |
0c9e63fd ED |
915 | if (fd < files->next_fd) |
916 | files->next_fd = fd; | |
1da177e4 LT |
917 | } |
918 | ||
919 | void fastcall put_unused_fd(unsigned int fd) | |
920 | { | |
921 | struct files_struct *files = current->files; | |
922 | spin_lock(&files->file_lock); | |
923 | __put_unused_fd(files, fd); | |
924 | spin_unlock(&files->file_lock); | |
925 | } | |
926 | ||
927 | EXPORT_SYMBOL(put_unused_fd); | |
928 | ||
929 | /* | |
5590ff0d | 930 | * Install a file pointer in the fd array. |
1da177e4 LT |
931 | * |
932 | * The VFS is full of places where we drop the files lock between | |
933 | * setting the open_fds bitmap and installing the file in the file | |
934 | * array. At any such point, we are vulnerable to a dup2() race | |
935 | * installing a file in the array before us. We need to detect this and | |
936 | * fput() the struct file we are about to overwrite in this case. | |
937 | * | |
938 | * It should never happen - if we allow dup2() do it, _really_ bad things | |
939 | * will follow. | |
940 | */ | |
941 | ||
942 | void fastcall fd_install(unsigned int fd, struct file * file) | |
943 | { | |
944 | struct files_struct *files = current->files; | |
badf1662 | 945 | struct fdtable *fdt; |
1da177e4 | 946 | spin_lock(&files->file_lock); |
badf1662 | 947 | fdt = files_fdtable(files); |
ab2af1f5 DS |
948 | BUG_ON(fdt->fd[fd] != NULL); |
949 | rcu_assign_pointer(fdt->fd[fd], file); | |
1da177e4 LT |
950 | spin_unlock(&files->file_lock); |
951 | } | |
952 | ||
953 | EXPORT_SYMBOL(fd_install); | |
954 | ||
5590ff0d | 955 | long do_sys_open(int dfd, const char __user *filename, int flags, int mode) |
1da177e4 | 956 | { |
e922efc3 MS |
957 | char *tmp = getname(filename); |
958 | int fd = PTR_ERR(tmp); | |
1da177e4 | 959 | |
1da177e4 LT |
960 | if (!IS_ERR(tmp)) { |
961 | fd = get_unused_fd(); | |
962 | if (fd >= 0) { | |
5590ff0d | 963 | struct file *f = do_filp_open(dfd, tmp, flags, mode); |
fed2fc18 TN |
964 | if (IS_ERR(f)) { |
965 | put_unused_fd(fd); | |
966 | fd = PTR_ERR(f); | |
967 | } else { | |
0eeca283 | 968 | fsnotify_open(f->f_dentry); |
fed2fc18 TN |
969 | fd_install(fd, f); |
970 | } | |
1da177e4 | 971 | } |
1da177e4 LT |
972 | putname(tmp); |
973 | } | |
974 | return fd; | |
1da177e4 | 975 | } |
e922efc3 MS |
976 | |
977 | asmlinkage long sys_open(const char __user *filename, int flags, int mode) | |
978 | { | |
385910f2 LT |
979 | long ret; |
980 | ||
e922efc3 MS |
981 | if (force_o_largefile()) |
982 | flags |= O_LARGEFILE; | |
983 | ||
385910f2 LT |
984 | ret = do_sys_open(AT_FDCWD, filename, flags, mode); |
985 | /* avoid REGPARM breakage on x86: */ | |
986 | prevent_tail_call(ret); | |
987 | return ret; | |
e922efc3 | 988 | } |
1da177e4 LT |
989 | EXPORT_SYMBOL_GPL(sys_open); |
990 | ||
5590ff0d UD |
991 | asmlinkage long sys_openat(int dfd, const char __user *filename, int flags, |
992 | int mode) | |
993 | { | |
385910f2 LT |
994 | long ret; |
995 | ||
5590ff0d UD |
996 | if (force_o_largefile()) |
997 | flags |= O_LARGEFILE; | |
998 | ||
385910f2 LT |
999 | ret = do_sys_open(dfd, filename, flags, mode); |
1000 | /* avoid REGPARM breakage on x86: */ | |
1001 | prevent_tail_call(ret); | |
1002 | return ret; | |
5590ff0d | 1003 | } |
5590ff0d | 1004 | |
1da177e4 LT |
1005 | #ifndef __alpha__ |
1006 | ||
1007 | /* | |
1008 | * For backward compatibility? Maybe this should be moved | |
1009 | * into arch/i386 instead? | |
1010 | */ | |
1011 | asmlinkage long sys_creat(const char __user * pathname, int mode) | |
1012 | { | |
1013 | return sys_open(pathname, O_CREAT | O_WRONLY | O_TRUNC, mode); | |
1014 | } | |
1015 | ||
1016 | #endif | |
1017 | ||
1018 | /* | |
1019 | * "id" is the POSIX thread ID. We use the | |
1020 | * files pointer for this.. | |
1021 | */ | |
1022 | int filp_close(struct file *filp, fl_owner_t id) | |
1023 | { | |
45778ca8 | 1024 | int retval = 0; |
1da177e4 LT |
1025 | |
1026 | if (!file_count(filp)) { | |
1027 | printk(KERN_ERR "VFS: Close: file count is 0\n"); | |
45778ca8 | 1028 | return 0; |
1da177e4 LT |
1029 | } |
1030 | ||
45778ca8 | 1031 | if (filp->f_op && filp->f_op->flush) |
75e1fcc0 | 1032 | retval = filp->f_op->flush(filp, id); |
1da177e4 LT |
1033 | |
1034 | dnotify_flush(filp, id); | |
1035 | locks_remove_posix(filp, id); | |
1036 | fput(filp); | |
1037 | return retval; | |
1038 | } | |
1039 | ||
1040 | EXPORT_SYMBOL(filp_close); | |
1041 | ||
1042 | /* | |
1043 | * Careful here! We test whether the file pointer is NULL before | |
1044 | * releasing the fd. This ensures that one clone task can't release | |
1045 | * an fd while another clone is opening it. | |
1046 | */ | |
1047 | asmlinkage long sys_close(unsigned int fd) | |
1048 | { | |
1049 | struct file * filp; | |
1050 | struct files_struct *files = current->files; | |
badf1662 | 1051 | struct fdtable *fdt; |
ee731f4f | 1052 | int retval; |
1da177e4 LT |
1053 | |
1054 | spin_lock(&files->file_lock); | |
badf1662 DS |
1055 | fdt = files_fdtable(files); |
1056 | if (fd >= fdt->max_fds) | |
1da177e4 | 1057 | goto out_unlock; |
badf1662 | 1058 | filp = fdt->fd[fd]; |
1da177e4 LT |
1059 | if (!filp) |
1060 | goto out_unlock; | |
ab2af1f5 | 1061 | rcu_assign_pointer(fdt->fd[fd], NULL); |
badf1662 | 1062 | FD_CLR(fd, fdt->close_on_exec); |
1da177e4 LT |
1063 | __put_unused_fd(files, fd); |
1064 | spin_unlock(&files->file_lock); | |
ee731f4f EP |
1065 | retval = filp_close(filp, files); |
1066 | ||
1067 | /* can't restart close syscall because file table entry was cleared */ | |
1068 | if (unlikely(retval == -ERESTARTSYS || | |
1069 | retval == -ERESTARTNOINTR || | |
1070 | retval == -ERESTARTNOHAND || | |
1071 | retval == -ERESTART_RESTARTBLOCK)) | |
1072 | retval = -EINTR; | |
1073 | ||
1074 | return retval; | |
1da177e4 LT |
1075 | |
1076 | out_unlock: | |
1077 | spin_unlock(&files->file_lock); | |
1078 | return -EBADF; | |
1079 | } | |
1080 | ||
1081 | EXPORT_SYMBOL(sys_close); | |
1082 | ||
1083 | /* | |
1084 | * This routine simulates a hangup on the tty, to arrange that users | |
1085 | * are given clean terminals at login time. | |
1086 | */ | |
1087 | asmlinkage long sys_vhangup(void) | |
1088 | { | |
1089 | if (capable(CAP_SYS_TTY_CONFIG)) { | |
24ec839c | 1090 | /* XXX: this needs locking */ |
1da177e4 LT |
1091 | tty_vhangup(current->signal->tty); |
1092 | return 0; | |
1093 | } | |
1094 | return -EPERM; | |
1095 | } | |
1096 | ||
1097 | /* | |
1098 | * Called when an inode is about to be open. | |
1099 | * We use this to disallow opening large files on 32bit systems if | |
1100 | * the caller didn't specify O_LARGEFILE. On 64bit systems we force | |
1101 | * on this flag in sys_open. | |
1102 | */ | |
1103 | int generic_file_open(struct inode * inode, struct file * filp) | |
1104 | { | |
1105 | if (!(filp->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS) | |
1106 | return -EFBIG; | |
1107 | return 0; | |
1108 | } | |
1109 | ||
1110 | EXPORT_SYMBOL(generic_file_open); | |
1111 | ||
1112 | /* | |
1113 | * This is used by subsystems that don't want seekable | |
1114 | * file descriptors | |
1115 | */ | |
1116 | int nonseekable_open(struct inode *inode, struct file *filp) | |
1117 | { | |
1118 | filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE); | |
1119 | return 0; | |
1120 | } | |
1121 | ||
1122 | EXPORT_SYMBOL(nonseekable_open); |