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> |
1da177e4 | 29 | |
726c3342 | 30 | int vfs_statfs(struct dentry *dentry, struct kstatfs *buf) |
1da177e4 LT |
31 | { |
32 | int retval = -ENODEV; | |
33 | ||
726c3342 | 34 | if (dentry) { |
1da177e4 | 35 | retval = -ENOSYS; |
726c3342 | 36 | if (dentry->d_sb->s_op->statfs) { |
1da177e4 | 37 | memset(buf, 0, sizeof(*buf)); |
726c3342 | 38 | retval = security_sb_statfs(dentry); |
1da177e4 LT |
39 | if (retval) |
40 | return retval; | |
726c3342 | 41 | retval = dentry->d_sb->s_op->statfs(dentry, buf); |
1da177e4 LT |
42 | if (retval == 0 && buf->f_frsize == 0) |
43 | buf->f_frsize = buf->f_bsize; | |
44 | } | |
45 | } | |
46 | return retval; | |
47 | } | |
48 | ||
49 | EXPORT_SYMBOL(vfs_statfs); | |
50 | ||
726c3342 | 51 | static int vfs_statfs_native(struct dentry *dentry, struct statfs *buf) |
1da177e4 LT |
52 | { |
53 | struct kstatfs st; | |
54 | int retval; | |
55 | ||
726c3342 | 56 | retval = vfs_statfs(dentry, &st); |
1da177e4 LT |
57 | if (retval) |
58 | return retval; | |
59 | ||
60 | if (sizeof(*buf) == sizeof(st)) | |
61 | memcpy(buf, &st, sizeof(st)); | |
62 | else { | |
63 | if (sizeof buf->f_blocks == 4) { | |
64 | if ((st.f_blocks | st.f_bfree | st.f_bavail) & | |
65 | 0xffffffff00000000ULL) | |
66 | return -EOVERFLOW; | |
67 | /* | |
68 | * f_files and f_ffree may be -1; it's okay to stuff | |
69 | * that into 32 bits | |
70 | */ | |
71 | if (st.f_files != -1 && | |
72 | (st.f_files & 0xffffffff00000000ULL)) | |
73 | return -EOVERFLOW; | |
74 | if (st.f_ffree != -1 && | |
75 | (st.f_ffree & 0xffffffff00000000ULL)) | |
76 | return -EOVERFLOW; | |
77 | } | |
78 | ||
79 | buf->f_type = st.f_type; | |
80 | buf->f_bsize = st.f_bsize; | |
81 | buf->f_blocks = st.f_blocks; | |
82 | buf->f_bfree = st.f_bfree; | |
83 | buf->f_bavail = st.f_bavail; | |
84 | buf->f_files = st.f_files; | |
85 | buf->f_ffree = st.f_ffree; | |
86 | buf->f_fsid = st.f_fsid; | |
87 | buf->f_namelen = st.f_namelen; | |
88 | buf->f_frsize = st.f_frsize; | |
89 | memset(buf->f_spare, 0, sizeof(buf->f_spare)); | |
90 | } | |
91 | return 0; | |
92 | } | |
93 | ||
726c3342 | 94 | static int vfs_statfs64(struct dentry *dentry, struct statfs64 *buf) |
1da177e4 LT |
95 | { |
96 | struct kstatfs st; | |
97 | int retval; | |
98 | ||
726c3342 | 99 | retval = vfs_statfs(dentry, &st); |
1da177e4 LT |
100 | if (retval) |
101 | return retval; | |
102 | ||
103 | if (sizeof(*buf) == sizeof(st)) | |
104 | memcpy(buf, &st, sizeof(st)); | |
105 | else { | |
106 | buf->f_type = st.f_type; | |
107 | buf->f_bsize = st.f_bsize; | |
108 | buf->f_blocks = st.f_blocks; | |
109 | buf->f_bfree = st.f_bfree; | |
110 | buf->f_bavail = st.f_bavail; | |
111 | buf->f_files = st.f_files; | |
112 | buf->f_ffree = st.f_ffree; | |
113 | buf->f_fsid = st.f_fsid; | |
114 | buf->f_namelen = st.f_namelen; | |
115 | buf->f_frsize = st.f_frsize; | |
116 | memset(buf->f_spare, 0, sizeof(buf->f_spare)); | |
117 | } | |
118 | return 0; | |
119 | } | |
120 | ||
121 | asmlinkage long sys_statfs(const char __user * path, struct statfs __user * buf) | |
122 | { | |
123 | struct nameidata nd; | |
124 | int error; | |
125 | ||
126 | error = user_path_walk(path, &nd); | |
127 | if (!error) { | |
128 | struct statfs tmp; | |
726c3342 | 129 | error = vfs_statfs_native(nd.dentry, &tmp); |
1da177e4 LT |
130 | if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) |
131 | error = -EFAULT; | |
132 | path_release(&nd); | |
133 | } | |
134 | return error; | |
135 | } | |
136 | ||
137 | ||
138 | asmlinkage long sys_statfs64(const char __user *path, size_t sz, struct statfs64 __user *buf) | |
139 | { | |
140 | struct nameidata nd; | |
141 | long error; | |
142 | ||
143 | if (sz != sizeof(*buf)) | |
144 | return -EINVAL; | |
145 | error = user_path_walk(path, &nd); | |
146 | if (!error) { | |
147 | struct statfs64 tmp; | |
726c3342 | 148 | error = vfs_statfs64(nd.dentry, &tmp); |
1da177e4 LT |
149 | if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) |
150 | error = -EFAULT; | |
151 | path_release(&nd); | |
152 | } | |
153 | return error; | |
154 | } | |
155 | ||
156 | ||
157 | asmlinkage long sys_fstatfs(unsigned int fd, struct statfs __user * buf) | |
158 | { | |
159 | struct file * file; | |
160 | struct statfs tmp; | |
161 | int error; | |
162 | ||
163 | error = -EBADF; | |
164 | file = fget(fd); | |
165 | if (!file) | |
166 | goto out; | |
0f7fc9e4 | 167 | error = vfs_statfs_native(file->f_path.dentry, &tmp); |
1da177e4 LT |
168 | if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) |
169 | error = -EFAULT; | |
170 | fput(file); | |
171 | out: | |
172 | return error; | |
173 | } | |
174 | ||
175 | asmlinkage long sys_fstatfs64(unsigned int fd, size_t sz, struct statfs64 __user *buf) | |
176 | { | |
177 | struct file * file; | |
178 | struct statfs64 tmp; | |
179 | int error; | |
180 | ||
181 | if (sz != sizeof(*buf)) | |
182 | return -EINVAL; | |
183 | ||
184 | error = -EBADF; | |
185 | file = fget(fd); | |
186 | if (!file) | |
187 | goto out; | |
0f7fc9e4 | 188 | error = vfs_statfs64(file->f_path.dentry, &tmp); |
1da177e4 LT |
189 | if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) |
190 | error = -EFAULT; | |
191 | fput(file); | |
192 | out: | |
193 | return error; | |
194 | } | |
195 | ||
4a30131e N |
196 | int do_truncate(struct dentry *dentry, loff_t length, unsigned int time_attrs, |
197 | struct file *filp) | |
1da177e4 LT |
198 | { |
199 | int err; | |
200 | struct iattr newattrs; | |
201 | ||
202 | /* Not pretty: "inode->i_size" shouldn't really be signed. But it is. */ | |
203 | if (length < 0) | |
204 | return -EINVAL; | |
205 | ||
206 | newattrs.ia_size = length; | |
4a30131e | 207 | newattrs.ia_valid = ATTR_SIZE | time_attrs; |
cc4e69de MS |
208 | if (filp) { |
209 | newattrs.ia_file = filp; | |
210 | newattrs.ia_valid |= ATTR_FILE; | |
211 | } | |
1da177e4 | 212 | |
1b1dcc1b | 213 | mutex_lock(&dentry->d_inode->i_mutex); |
1da177e4 | 214 | err = notify_change(dentry, &newattrs); |
1b1dcc1b | 215 | mutex_unlock(&dentry->d_inode->i_mutex); |
1da177e4 LT |
216 | return err; |
217 | } | |
218 | ||
b01ec0ef | 219 | static long do_sys_truncate(const char __user * path, loff_t length) |
1da177e4 LT |
220 | { |
221 | struct nameidata nd; | |
222 | struct inode * inode; | |
223 | int error; | |
224 | ||
225 | error = -EINVAL; | |
226 | if (length < 0) /* sorry, but loff_t says... */ | |
227 | goto out; | |
228 | ||
229 | error = user_path_walk(path, &nd); | |
230 | if (error) | |
231 | goto out; | |
232 | inode = nd.dentry->d_inode; | |
233 | ||
234 | /* For directories it's -EISDIR, for other non-regulars - -EINVAL */ | |
235 | error = -EISDIR; | |
236 | if (S_ISDIR(inode->i_mode)) | |
237 | goto dput_and_out; | |
238 | ||
239 | error = -EINVAL; | |
240 | if (!S_ISREG(inode->i_mode)) | |
241 | goto dput_and_out; | |
242 | ||
e4543edd | 243 | error = vfs_permission(&nd, MAY_WRITE); |
1da177e4 LT |
244 | if (error) |
245 | goto dput_and_out; | |
246 | ||
247 | error = -EROFS; | |
248 | if (IS_RDONLY(inode)) | |
249 | goto dput_and_out; | |
250 | ||
251 | error = -EPERM; | |
252 | if (IS_IMMUTABLE(inode) || IS_APPEND(inode)) | |
253 | goto dput_and_out; | |
254 | ||
255 | /* | |
256 | * Make sure that there are no leases. | |
257 | */ | |
258 | error = break_lease(inode, FMODE_WRITE); | |
259 | if (error) | |
260 | goto dput_and_out; | |
261 | ||
262 | error = get_write_access(inode); | |
263 | if (error) | |
264 | goto dput_and_out; | |
265 | ||
266 | error = locks_verify_truncate(inode, NULL, length); | |
267 | if (!error) { | |
268 | DQUOT_INIT(inode); | |
4a30131e | 269 | error = do_truncate(nd.dentry, length, 0, NULL); |
1da177e4 LT |
270 | } |
271 | put_write_access(inode); | |
272 | ||
273 | dput_and_out: | |
274 | path_release(&nd); | |
275 | out: | |
276 | return error; | |
277 | } | |
278 | ||
279 | asmlinkage long sys_truncate(const char __user * path, unsigned long length) | |
280 | { | |
281 | /* on 32-bit boxen it will cut the range 2^31--2^32-1 off */ | |
282 | return do_sys_truncate(path, (long)length); | |
283 | } | |
284 | ||
b01ec0ef | 285 | static long do_sys_ftruncate(unsigned int fd, loff_t length, int small) |
1da177e4 LT |
286 | { |
287 | struct inode * inode; | |
288 | struct dentry *dentry; | |
289 | struct file * file; | |
290 | int error; | |
291 | ||
292 | error = -EINVAL; | |
293 | if (length < 0) | |
294 | goto out; | |
295 | error = -EBADF; | |
296 | file = fget(fd); | |
297 | if (!file) | |
298 | goto out; | |
299 | ||
300 | /* explicitly opened as large or we are on 64-bit box */ | |
301 | if (file->f_flags & O_LARGEFILE) | |
302 | small = 0; | |
303 | ||
0f7fc9e4 | 304 | dentry = file->f_path.dentry; |
1da177e4 LT |
305 | inode = dentry->d_inode; |
306 | error = -EINVAL; | |
307 | if (!S_ISREG(inode->i_mode) || !(file->f_mode & FMODE_WRITE)) | |
308 | goto out_putf; | |
309 | ||
310 | error = -EINVAL; | |
311 | /* Cannot ftruncate over 2^31 bytes without large file support */ | |
312 | if (small && length > MAX_NON_LFS) | |
313 | goto out_putf; | |
314 | ||
315 | error = -EPERM; | |
316 | if (IS_APPEND(inode)) | |
317 | goto out_putf; | |
318 | ||
319 | error = locks_verify_truncate(inode, file, length); | |
320 | if (!error) | |
6e656be8 | 321 | error = do_truncate(dentry, length, ATTR_MTIME|ATTR_CTIME, file); |
1da177e4 LT |
322 | out_putf: |
323 | fput(file); | |
324 | out: | |
325 | return error; | |
326 | } | |
327 | ||
328 | asmlinkage long sys_ftruncate(unsigned int fd, unsigned long length) | |
329 | { | |
0a489cb3 | 330 | long ret = do_sys_ftruncate(fd, length, 1); |
385910f2 | 331 | /* avoid REGPARM breakage on x86: */ |
0a489cb3 LT |
332 | prevent_tail_call(ret); |
333 | return ret; | |
1da177e4 LT |
334 | } |
335 | ||
336 | /* LFS versions of truncate are only needed on 32 bit machines */ | |
337 | #if BITS_PER_LONG == 32 | |
338 | asmlinkage long sys_truncate64(const char __user * path, loff_t length) | |
339 | { | |
340 | return do_sys_truncate(path, length); | |
341 | } | |
342 | ||
343 | asmlinkage long sys_ftruncate64(unsigned int fd, loff_t length) | |
344 | { | |
0a489cb3 | 345 | long ret = do_sys_ftruncate(fd, length, 0); |
385910f2 | 346 | /* avoid REGPARM breakage on x86: */ |
0a489cb3 LT |
347 | prevent_tail_call(ret); |
348 | return ret; | |
1da177e4 LT |
349 | } |
350 | #endif | |
351 | ||
1da177e4 LT |
352 | /* |
353 | * access() needs to use the real uid/gid, not the effective uid/gid. | |
354 | * We do this by temporarily clearing all FS-related capabilities and | |
355 | * switching the fsuid/fsgid around to the real ones. | |
356 | */ | |
5590ff0d | 357 | asmlinkage long sys_faccessat(int dfd, const char __user *filename, int mode) |
1da177e4 LT |
358 | { |
359 | struct nameidata nd; | |
360 | int old_fsuid, old_fsgid; | |
361 | kernel_cap_t old_cap; | |
362 | int res; | |
363 | ||
364 | if (mode & ~S_IRWXO) /* where's F_OK, X_OK, W_OK, R_OK? */ | |
365 | return -EINVAL; | |
366 | ||
367 | old_fsuid = current->fsuid; | |
368 | old_fsgid = current->fsgid; | |
369 | old_cap = current->cap_effective; | |
370 | ||
371 | current->fsuid = current->uid; | |
372 | current->fsgid = current->gid; | |
373 | ||
374 | /* | |
375 | * Clear the capabilities if we switch to a non-root user | |
376 | * | |
377 | * FIXME: There is a race here against sys_capset. The | |
378 | * capabilities can change yet we will restore the old | |
379 | * value below. We should hold task_capabilities_lock, | |
380 | * but we cannot because user_path_walk can sleep. | |
381 | */ | |
382 | if (current->uid) | |
383 | cap_clear(current->cap_effective); | |
384 | else | |
385 | current->cap_effective = current->cap_permitted; | |
386 | ||
5590ff0d | 387 | res = __user_walk_fd(dfd, filename, LOOKUP_FOLLOW|LOOKUP_ACCESS, &nd); |
6902d925 DH |
388 | if (res) |
389 | goto out; | |
390 | ||
391 | res = vfs_permission(&nd, mode); | |
392 | /* SuS v2 requires we report a read only fs too */ | |
393 | if(res || !(mode & S_IWOTH) || | |
394 | special_file(nd.dentry->d_inode->i_mode)) | |
395 | goto out_path_release; | |
396 | ||
397 | if(IS_RDONLY(nd.dentry->d_inode)) | |
398 | res = -EROFS; | |
1da177e4 | 399 | |
6902d925 DH |
400 | out_path_release: |
401 | path_release(&nd); | |
402 | out: | |
1da177e4 LT |
403 | current->fsuid = old_fsuid; |
404 | current->fsgid = old_fsgid; | |
405 | current->cap_effective = old_cap; | |
406 | ||
407 | return res; | |
408 | } | |
409 | ||
5590ff0d UD |
410 | asmlinkage long sys_access(const char __user *filename, int mode) |
411 | { | |
412 | return sys_faccessat(AT_FDCWD, filename, mode); | |
413 | } | |
414 | ||
1da177e4 LT |
415 | asmlinkage long sys_chdir(const char __user * filename) |
416 | { | |
417 | struct nameidata nd; | |
418 | int error; | |
419 | ||
650a8983 MS |
420 | error = __user_walk(filename, |
421 | LOOKUP_FOLLOW|LOOKUP_DIRECTORY|LOOKUP_CHDIR, &nd); | |
1da177e4 LT |
422 | if (error) |
423 | goto out; | |
424 | ||
e4543edd | 425 | error = vfs_permission(&nd, MAY_EXEC); |
1da177e4 LT |
426 | if (error) |
427 | goto dput_and_out; | |
428 | ||
429 | set_fs_pwd(current->fs, nd.mnt, nd.dentry); | |
430 | ||
431 | dput_and_out: | |
432 | path_release(&nd); | |
433 | out: | |
434 | return error; | |
435 | } | |
436 | ||
437 | asmlinkage long sys_fchdir(unsigned int fd) | |
438 | { | |
439 | struct file *file; | |
440 | struct dentry *dentry; | |
441 | struct inode *inode; | |
442 | struct vfsmount *mnt; | |
443 | int error; | |
444 | ||
445 | error = -EBADF; | |
446 | file = fget(fd); | |
447 | if (!file) | |
448 | goto out; | |
449 | ||
0f7fc9e4 JJS |
450 | dentry = file->f_path.dentry; |
451 | mnt = file->f_path.mnt; | |
1da177e4 LT |
452 | inode = dentry->d_inode; |
453 | ||
454 | error = -ENOTDIR; | |
455 | if (!S_ISDIR(inode->i_mode)) | |
456 | goto out_putf; | |
457 | ||
8c744fb8 | 458 | error = file_permission(file, MAY_EXEC); |
1da177e4 LT |
459 | if (!error) |
460 | set_fs_pwd(current->fs, mnt, dentry); | |
461 | out_putf: | |
462 | fput(file); | |
463 | out: | |
464 | return error; | |
465 | } | |
466 | ||
467 | asmlinkage long sys_chroot(const char __user * filename) | |
468 | { | |
469 | struct nameidata nd; | |
470 | int error; | |
471 | ||
472 | error = __user_walk(filename, LOOKUP_FOLLOW | LOOKUP_DIRECTORY | LOOKUP_NOALT, &nd); | |
473 | if (error) | |
474 | goto out; | |
475 | ||
e4543edd | 476 | error = vfs_permission(&nd, MAY_EXEC); |
1da177e4 LT |
477 | if (error) |
478 | goto dput_and_out; | |
479 | ||
480 | error = -EPERM; | |
481 | if (!capable(CAP_SYS_CHROOT)) | |
482 | goto dput_and_out; | |
483 | ||
484 | set_fs_root(current->fs, nd.mnt, nd.dentry); | |
485 | set_fs_altroot(); | |
486 | error = 0; | |
487 | dput_and_out: | |
488 | path_release(&nd); | |
489 | out: | |
490 | return error; | |
491 | } | |
492 | ||
493 | asmlinkage long sys_fchmod(unsigned int fd, mode_t mode) | |
494 | { | |
495 | struct inode * inode; | |
496 | struct dentry * dentry; | |
497 | struct file * file; | |
498 | int err = -EBADF; | |
499 | struct iattr newattrs; | |
500 | ||
501 | file = fget(fd); | |
502 | if (!file) | |
503 | goto out; | |
504 | ||
0f7fc9e4 | 505 | dentry = file->f_path.dentry; |
1da177e4 LT |
506 | inode = dentry->d_inode; |
507 | ||
9c937dcc | 508 | audit_inode(NULL, inode); |
73241ccc | 509 | |
1da177e4 LT |
510 | err = -EROFS; |
511 | if (IS_RDONLY(inode)) | |
512 | goto out_putf; | |
513 | err = -EPERM; | |
514 | if (IS_IMMUTABLE(inode) || IS_APPEND(inode)) | |
515 | goto out_putf; | |
1b1dcc1b | 516 | mutex_lock(&inode->i_mutex); |
1da177e4 LT |
517 | if (mode == (mode_t) -1) |
518 | mode = inode->i_mode; | |
519 | newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO); | |
520 | newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; | |
521 | err = notify_change(dentry, &newattrs); | |
1b1dcc1b | 522 | mutex_unlock(&inode->i_mutex); |
1da177e4 LT |
523 | |
524 | out_putf: | |
525 | fput(file); | |
526 | out: | |
527 | return err; | |
528 | } | |
529 | ||
5590ff0d UD |
530 | asmlinkage long sys_fchmodat(int dfd, const char __user *filename, |
531 | mode_t mode) | |
1da177e4 LT |
532 | { |
533 | struct nameidata nd; | |
534 | struct inode * inode; | |
535 | int error; | |
536 | struct iattr newattrs; | |
537 | ||
5590ff0d | 538 | error = __user_walk_fd(dfd, filename, LOOKUP_FOLLOW, &nd); |
1da177e4 LT |
539 | if (error) |
540 | goto out; | |
541 | inode = nd.dentry->d_inode; | |
542 | ||
543 | error = -EROFS; | |
544 | if (IS_RDONLY(inode)) | |
545 | goto dput_and_out; | |
546 | ||
547 | error = -EPERM; | |
548 | if (IS_IMMUTABLE(inode) || IS_APPEND(inode)) | |
549 | goto dput_and_out; | |
550 | ||
1b1dcc1b | 551 | mutex_lock(&inode->i_mutex); |
1da177e4 LT |
552 | if (mode == (mode_t) -1) |
553 | mode = inode->i_mode; | |
554 | newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO); | |
555 | newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; | |
556 | error = notify_change(nd.dentry, &newattrs); | |
1b1dcc1b | 557 | mutex_unlock(&inode->i_mutex); |
1da177e4 LT |
558 | |
559 | dput_and_out: | |
560 | path_release(&nd); | |
561 | out: | |
562 | return error; | |
563 | } | |
564 | ||
5590ff0d UD |
565 | asmlinkage long sys_chmod(const char __user *filename, mode_t mode) |
566 | { | |
567 | return sys_fchmodat(AT_FDCWD, filename, mode); | |
568 | } | |
569 | ||
1da177e4 LT |
570 | static int chown_common(struct dentry * dentry, uid_t user, gid_t group) |
571 | { | |
572 | struct inode * inode; | |
573 | int error; | |
574 | struct iattr newattrs; | |
575 | ||
576 | error = -ENOENT; | |
577 | if (!(inode = dentry->d_inode)) { | |
578 | printk(KERN_ERR "chown_common: NULL inode\n"); | |
579 | goto out; | |
580 | } | |
581 | error = -EROFS; | |
582 | if (IS_RDONLY(inode)) | |
583 | goto out; | |
584 | error = -EPERM; | |
585 | if (IS_IMMUTABLE(inode) || IS_APPEND(inode)) | |
586 | goto out; | |
587 | newattrs.ia_valid = ATTR_CTIME; | |
588 | if (user != (uid_t) -1) { | |
589 | newattrs.ia_valid |= ATTR_UID; | |
590 | newattrs.ia_uid = user; | |
591 | } | |
592 | if (group != (gid_t) -1) { | |
593 | newattrs.ia_valid |= ATTR_GID; | |
594 | newattrs.ia_gid = group; | |
595 | } | |
596 | if (!S_ISDIR(inode->i_mode)) | |
597 | newattrs.ia_valid |= ATTR_KILL_SUID|ATTR_KILL_SGID; | |
1b1dcc1b | 598 | mutex_lock(&inode->i_mutex); |
1da177e4 | 599 | error = notify_change(dentry, &newattrs); |
1b1dcc1b | 600 | mutex_unlock(&inode->i_mutex); |
1da177e4 LT |
601 | out: |
602 | return error; | |
603 | } | |
604 | ||
605 | asmlinkage long sys_chown(const char __user * filename, uid_t user, gid_t group) | |
606 | { | |
607 | struct nameidata nd; | |
608 | int error; | |
609 | ||
610 | error = user_path_walk(filename, &nd); | |
6902d925 DH |
611 | if (error) |
612 | goto out; | |
613 | error = chown_common(nd.dentry, user, group); | |
614 | path_release(&nd); | |
615 | out: | |
1da177e4 LT |
616 | return error; |
617 | } | |
618 | ||
5590ff0d UD |
619 | asmlinkage long sys_fchownat(int dfd, const char __user *filename, uid_t user, |
620 | gid_t group, int flag) | |
621 | { | |
622 | struct nameidata nd; | |
623 | int error = -EINVAL; | |
624 | int follow; | |
625 | ||
626 | if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0) | |
627 | goto out; | |
628 | ||
629 | follow = (flag & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW; | |
630 | error = __user_walk_fd(dfd, filename, follow, &nd); | |
6902d925 DH |
631 | if (error) |
632 | goto out; | |
633 | error = chown_common(nd.dentry, user, group); | |
634 | path_release(&nd); | |
5590ff0d UD |
635 | out: |
636 | return error; | |
637 | } | |
638 | ||
1da177e4 LT |
639 | asmlinkage long sys_lchown(const char __user * filename, uid_t user, gid_t group) |
640 | { | |
641 | struct nameidata nd; | |
642 | int error; | |
643 | ||
644 | error = user_path_walk_link(filename, &nd); | |
6902d925 DH |
645 | if (error) |
646 | goto out; | |
647 | error = chown_common(nd.dentry, user, group); | |
648 | path_release(&nd); | |
649 | out: | |
1da177e4 LT |
650 | return error; |
651 | } | |
652 | ||
653 | ||
654 | asmlinkage long sys_fchown(unsigned int fd, uid_t user, gid_t group) | |
655 | { | |
656 | struct file * file; | |
657 | int error = -EBADF; | |
6902d925 | 658 | struct dentry * dentry; |
1da177e4 LT |
659 | |
660 | file = fget(fd); | |
6902d925 DH |
661 | if (!file) |
662 | goto out; | |
663 | ||
0f7fc9e4 | 664 | dentry = file->f_path.dentry; |
6902d925 DH |
665 | audit_inode(NULL, dentry->d_inode); |
666 | error = chown_common(dentry, user, group); | |
667 | fput(file); | |
668 | out: | |
1da177e4 LT |
669 | return error; |
670 | } | |
671 | ||
a1a5b3d9 | 672 | static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt, |
834f2a4a TM |
673 | int flags, struct file *f, |
674 | int (*open)(struct inode *, struct file *)) | |
1da177e4 | 675 | { |
1da177e4 LT |
676 | struct inode *inode; |
677 | int error; | |
678 | ||
1da177e4 | 679 | f->f_flags = flags; |
a1a5b3d9 PS |
680 | f->f_mode = ((flags+1) & O_ACCMODE) | FMODE_LSEEK | |
681 | FMODE_PREAD | FMODE_PWRITE; | |
1da177e4 LT |
682 | inode = dentry->d_inode; |
683 | if (f->f_mode & FMODE_WRITE) { | |
684 | error = get_write_access(inode); | |
685 | if (error) | |
686 | goto cleanup_file; | |
687 | } | |
688 | ||
689 | f->f_mapping = inode->i_mapping; | |
0f7fc9e4 JJS |
690 | f->f_path.dentry = dentry; |
691 | f->f_path.mnt = mnt; | |
1da177e4 LT |
692 | f->f_pos = 0; |
693 | f->f_op = fops_get(inode->i_fop); | |
694 | file_move(f, &inode->i_sb->s_files); | |
695 | ||
834f2a4a TM |
696 | if (!open && f->f_op) |
697 | open = f->f_op->open; | |
698 | if (open) { | |
699 | error = open(inode, f); | |
1da177e4 LT |
700 | if (error) |
701 | goto cleanup_all; | |
702 | } | |
834f2a4a | 703 | |
1da177e4 LT |
704 | f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC); |
705 | ||
706 | file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping); | |
707 | ||
708 | /* NB: we're sure to have correct a_ops only after f_op->open */ | |
709 | if (f->f_flags & O_DIRECT) { | |
ceffc078 CO |
710 | if (!f->f_mapping->a_ops || |
711 | ((!f->f_mapping->a_ops->direct_IO) && | |
712 | (!f->f_mapping->a_ops->get_xip_page))) { | |
1da177e4 LT |
713 | fput(f); |
714 | f = ERR_PTR(-EINVAL); | |
715 | } | |
716 | } | |
717 | ||
718 | return f; | |
719 | ||
720 | cleanup_all: | |
721 | fops_put(f->f_op); | |
722 | if (f->f_mode & FMODE_WRITE) | |
723 | put_write_access(inode); | |
724 | file_kill(f); | |
0f7fc9e4 JJS |
725 | f->f_path.dentry = NULL; |
726 | f->f_path.mnt = NULL; | |
1da177e4 LT |
727 | cleanup_file: |
728 | put_filp(f); | |
1da177e4 LT |
729 | dput(dentry); |
730 | mntput(mnt); | |
731 | return ERR_PTR(error); | |
732 | } | |
733 | ||
a1a5b3d9 PS |
734 | /* |
735 | * Note that while the flag value (low two bits) for sys_open means: | |
736 | * 00 - read-only | |
737 | * 01 - write-only | |
738 | * 10 - read-write | |
739 | * 11 - special | |
740 | * it is changed into | |
741 | * 00 - no permissions needed | |
742 | * 01 - read-permission | |
743 | * 10 - write-permission | |
744 | * 11 - read-write | |
745 | * for the internal routines (ie open_namei()/follow_link() etc). 00 is | |
746 | * used by symlinks. | |
747 | */ | |
5590ff0d UD |
748 | static struct file *do_filp_open(int dfd, const char *filename, int flags, |
749 | int mode) | |
a1a5b3d9 PS |
750 | { |
751 | int namei_flags, error; | |
752 | struct nameidata nd; | |
a1a5b3d9 PS |
753 | |
754 | namei_flags = flags; | |
755 | if ((namei_flags+1) & O_ACCMODE) | |
756 | namei_flags++; | |
a1a5b3d9 | 757 | |
5590ff0d | 758 | error = open_namei(dfd, filename, namei_flags, mode, &nd); |
a1a5b3d9 | 759 | if (!error) |
834f2a4a | 760 | return nameidata_to_filp(&nd, flags); |
a1a5b3d9 | 761 | |
a1a5b3d9 PS |
762 | return ERR_PTR(error); |
763 | } | |
5590ff0d UD |
764 | |
765 | struct file *filp_open(const char *filename, int flags, int mode) | |
766 | { | |
767 | return do_filp_open(AT_FDCWD, filename, flags, mode); | |
768 | } | |
a1a5b3d9 PS |
769 | EXPORT_SYMBOL(filp_open); |
770 | ||
834f2a4a TM |
771 | /** |
772 | * lookup_instantiate_filp - instantiates the open intent filp | |
773 | * @nd: pointer to nameidata | |
774 | * @dentry: pointer to dentry | |
775 | * @open: open callback | |
776 | * | |
777 | * Helper for filesystems that want to use lookup open intents and pass back | |
778 | * a fully instantiated struct file to the caller. | |
779 | * This function is meant to be called from within a filesystem's | |
780 | * lookup method. | |
9a56c213 OD |
781 | * Beware of calling it for non-regular files! Those ->open methods might block |
782 | * (e.g. in fifo_open), leaving you with parent locked (and in case of fifo, | |
783 | * leading to a deadlock, as nobody can open that fifo anymore, because | |
784 | * another process to open fifo will block on locked parent when doing lookup). | |
834f2a4a TM |
785 | * Note that in case of error, nd->intent.open.file is destroyed, but the |
786 | * path information remains valid. | |
787 | * If the open callback is set to NULL, then the standard f_op->open() | |
788 | * filesystem callback is substituted. | |
789 | */ | |
790 | struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry *dentry, | |
791 | int (*open)(struct inode *, struct file *)) | |
792 | { | |
793 | if (IS_ERR(nd->intent.open.file)) | |
794 | goto out; | |
795 | if (IS_ERR(dentry)) | |
796 | goto out_err; | |
797 | nd->intent.open.file = __dentry_open(dget(dentry), mntget(nd->mnt), | |
798 | nd->intent.open.flags - 1, | |
799 | nd->intent.open.file, | |
800 | open); | |
801 | out: | |
802 | return nd->intent.open.file; | |
803 | out_err: | |
804 | release_open_intent(nd); | |
805 | nd->intent.open.file = (struct file *)dentry; | |
806 | goto out; | |
807 | } | |
808 | EXPORT_SYMBOL_GPL(lookup_instantiate_filp); | |
809 | ||
810 | /** | |
811 | * nameidata_to_filp - convert a nameidata to an open filp. | |
812 | * @nd: pointer to nameidata | |
813 | * @flags: open flags | |
814 | * | |
815 | * Note that this function destroys the original nameidata | |
816 | */ | |
817 | struct file *nameidata_to_filp(struct nameidata *nd, int flags) | |
818 | { | |
819 | struct file *filp; | |
820 | ||
821 | /* Pick up the filp from the open intent */ | |
822 | filp = nd->intent.open.file; | |
823 | /* Has the filesystem initialised the file for us? */ | |
0f7fc9e4 | 824 | if (filp->f_path.dentry == NULL) |
834f2a4a TM |
825 | filp = __dentry_open(nd->dentry, nd->mnt, flags, filp, NULL); |
826 | else | |
827 | path_release(nd); | |
828 | return filp; | |
829 | } | |
830 | ||
6fdcc216 PS |
831 | /* |
832 | * dentry_open() will have done dput(dentry) and mntput(mnt) if it returns an | |
833 | * error. | |
834 | */ | |
a1a5b3d9 PS |
835 | struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags) |
836 | { | |
837 | int error; | |
838 | struct file *f; | |
839 | ||
840 | error = -ENFILE; | |
841 | f = get_empty_filp(); | |
6fdcc216 PS |
842 | if (f == NULL) { |
843 | dput(dentry); | |
844 | mntput(mnt); | |
a1a5b3d9 | 845 | return ERR_PTR(error); |
6fdcc216 | 846 | } |
a1a5b3d9 | 847 | |
834f2a4a | 848 | return __dentry_open(dentry, mnt, flags, f, NULL); |
a1a5b3d9 | 849 | } |
1da177e4 LT |
850 | EXPORT_SYMBOL(dentry_open); |
851 | ||
852 | /* | |
853 | * Find an empty file descriptor entry, and mark it busy. | |
854 | */ | |
855 | int get_unused_fd(void) | |
856 | { | |
857 | struct files_struct * files = current->files; | |
858 | int fd, error; | |
badf1662 | 859 | struct fdtable *fdt; |
1da177e4 LT |
860 | |
861 | error = -EMFILE; | |
862 | spin_lock(&files->file_lock); | |
863 | ||
864 | repeat: | |
badf1662 | 865 | fdt = files_fdtable(files); |
bbea9f69 | 866 | fd = find_next_zero_bit(fdt->open_fds->fds_bits, fdt->max_fds, |
0c9e63fd | 867 | files->next_fd); |
1da177e4 LT |
868 | |
869 | /* | |
870 | * N.B. For clone tasks sharing a files structure, this test | |
871 | * will limit the total number of files that can be opened. | |
872 | */ | |
873 | if (fd >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur) | |
874 | goto out; | |
875 | ||
876 | /* Do we need to expand the fd array or fd set? */ | |
877 | error = expand_files(files, fd); | |
878 | if (error < 0) | |
879 | goto out; | |
880 | ||
881 | if (error) { | |
882 | /* | |
883 | * If we needed to expand the fs array we | |
884 | * might have blocked - try again. | |
885 | */ | |
886 | error = -EMFILE; | |
887 | goto repeat; | |
888 | } | |
889 | ||
badf1662 DS |
890 | FD_SET(fd, fdt->open_fds); |
891 | FD_CLR(fd, fdt->close_on_exec); | |
0c9e63fd | 892 | files->next_fd = fd + 1; |
1da177e4 LT |
893 | #if 1 |
894 | /* Sanity check */ | |
badf1662 | 895 | if (fdt->fd[fd] != NULL) { |
1da177e4 | 896 | printk(KERN_WARNING "get_unused_fd: slot %d not NULL!\n", fd); |
badf1662 | 897 | fdt->fd[fd] = NULL; |
1da177e4 LT |
898 | } |
899 | #endif | |
900 | error = fd; | |
901 | ||
902 | out: | |
903 | spin_unlock(&files->file_lock); | |
904 | return error; | |
905 | } | |
906 | ||
907 | EXPORT_SYMBOL(get_unused_fd); | |
908 | ||
b01ec0ef | 909 | static void __put_unused_fd(struct files_struct *files, unsigned int fd) |
1da177e4 | 910 | { |
badf1662 DS |
911 | struct fdtable *fdt = files_fdtable(files); |
912 | __FD_CLR(fd, fdt->open_fds); | |
0c9e63fd ED |
913 | if (fd < files->next_fd) |
914 | files->next_fd = fd; | |
1da177e4 LT |
915 | } |
916 | ||
917 | void fastcall put_unused_fd(unsigned int fd) | |
918 | { | |
919 | struct files_struct *files = current->files; | |
920 | spin_lock(&files->file_lock); | |
921 | __put_unused_fd(files, fd); | |
922 | spin_unlock(&files->file_lock); | |
923 | } | |
924 | ||
925 | EXPORT_SYMBOL(put_unused_fd); | |
926 | ||
927 | /* | |
5590ff0d | 928 | * Install a file pointer in the fd array. |
1da177e4 LT |
929 | * |
930 | * The VFS is full of places where we drop the files lock between | |
931 | * setting the open_fds bitmap and installing the file in the file | |
932 | * array. At any such point, we are vulnerable to a dup2() race | |
933 | * installing a file in the array before us. We need to detect this and | |
934 | * fput() the struct file we are about to overwrite in this case. | |
935 | * | |
936 | * It should never happen - if we allow dup2() do it, _really_ bad things | |
937 | * will follow. | |
938 | */ | |
939 | ||
940 | void fastcall fd_install(unsigned int fd, struct file * file) | |
941 | { | |
942 | struct files_struct *files = current->files; | |
badf1662 | 943 | struct fdtable *fdt; |
1da177e4 | 944 | spin_lock(&files->file_lock); |
badf1662 | 945 | fdt = files_fdtable(files); |
ab2af1f5 DS |
946 | BUG_ON(fdt->fd[fd] != NULL); |
947 | rcu_assign_pointer(fdt->fd[fd], file); | |
1da177e4 LT |
948 | spin_unlock(&files->file_lock); |
949 | } | |
950 | ||
951 | EXPORT_SYMBOL(fd_install); | |
952 | ||
5590ff0d | 953 | long do_sys_open(int dfd, const char __user *filename, int flags, int mode) |
1da177e4 | 954 | { |
e922efc3 MS |
955 | char *tmp = getname(filename); |
956 | int fd = PTR_ERR(tmp); | |
1da177e4 | 957 | |
1da177e4 LT |
958 | if (!IS_ERR(tmp)) { |
959 | fd = get_unused_fd(); | |
960 | if (fd >= 0) { | |
5590ff0d | 961 | struct file *f = do_filp_open(dfd, tmp, flags, mode); |
fed2fc18 TN |
962 | if (IS_ERR(f)) { |
963 | put_unused_fd(fd); | |
964 | fd = PTR_ERR(f); | |
965 | } else { | |
0f7fc9e4 | 966 | fsnotify_open(f->f_path.dentry); |
fed2fc18 TN |
967 | fd_install(fd, f); |
968 | } | |
1da177e4 | 969 | } |
1da177e4 LT |
970 | putname(tmp); |
971 | } | |
972 | return fd; | |
1da177e4 | 973 | } |
e922efc3 MS |
974 | |
975 | asmlinkage long sys_open(const char __user *filename, int flags, int mode) | |
976 | { | |
385910f2 LT |
977 | long ret; |
978 | ||
e922efc3 MS |
979 | if (force_o_largefile()) |
980 | flags |= O_LARGEFILE; | |
981 | ||
385910f2 LT |
982 | ret = do_sys_open(AT_FDCWD, filename, flags, mode); |
983 | /* avoid REGPARM breakage on x86: */ | |
984 | prevent_tail_call(ret); | |
985 | return ret; | |
e922efc3 | 986 | } |
1da177e4 LT |
987 | EXPORT_SYMBOL_GPL(sys_open); |
988 | ||
5590ff0d UD |
989 | asmlinkage long sys_openat(int dfd, const char __user *filename, int flags, |
990 | int mode) | |
991 | { | |
385910f2 LT |
992 | long ret; |
993 | ||
5590ff0d UD |
994 | if (force_o_largefile()) |
995 | flags |= O_LARGEFILE; | |
996 | ||
385910f2 LT |
997 | ret = do_sys_open(dfd, filename, flags, mode); |
998 | /* avoid REGPARM breakage on x86: */ | |
999 | prevent_tail_call(ret); | |
1000 | return ret; | |
5590ff0d | 1001 | } |
5590ff0d | 1002 | |
1da177e4 LT |
1003 | #ifndef __alpha__ |
1004 | ||
1005 | /* | |
1006 | * For backward compatibility? Maybe this should be moved | |
1007 | * into arch/i386 instead? | |
1008 | */ | |
1009 | asmlinkage long sys_creat(const char __user * pathname, int mode) | |
1010 | { | |
1011 | return sys_open(pathname, O_CREAT | O_WRONLY | O_TRUNC, mode); | |
1012 | } | |
1013 | ||
1014 | #endif | |
1015 | ||
1016 | /* | |
1017 | * "id" is the POSIX thread ID. We use the | |
1018 | * files pointer for this.. | |
1019 | */ | |
1020 | int filp_close(struct file *filp, fl_owner_t id) | |
1021 | { | |
45778ca8 | 1022 | int retval = 0; |
1da177e4 LT |
1023 | |
1024 | if (!file_count(filp)) { | |
1025 | printk(KERN_ERR "VFS: Close: file count is 0\n"); | |
45778ca8 | 1026 | return 0; |
1da177e4 LT |
1027 | } |
1028 | ||
45778ca8 | 1029 | if (filp->f_op && filp->f_op->flush) |
75e1fcc0 | 1030 | retval = filp->f_op->flush(filp, id); |
1da177e4 LT |
1031 | |
1032 | dnotify_flush(filp, id); | |
1033 | locks_remove_posix(filp, id); | |
1034 | fput(filp); | |
1035 | return retval; | |
1036 | } | |
1037 | ||
1038 | EXPORT_SYMBOL(filp_close); | |
1039 | ||
1040 | /* | |
1041 | * Careful here! We test whether the file pointer is NULL before | |
1042 | * releasing the fd. This ensures that one clone task can't release | |
1043 | * an fd while another clone is opening it. | |
1044 | */ | |
1045 | asmlinkage long sys_close(unsigned int fd) | |
1046 | { | |
1047 | struct file * filp; | |
1048 | struct files_struct *files = current->files; | |
badf1662 | 1049 | struct fdtable *fdt; |
ee731f4f | 1050 | int retval; |
1da177e4 LT |
1051 | |
1052 | spin_lock(&files->file_lock); | |
badf1662 DS |
1053 | fdt = files_fdtable(files); |
1054 | if (fd >= fdt->max_fds) | |
1da177e4 | 1055 | goto out_unlock; |
badf1662 | 1056 | filp = fdt->fd[fd]; |
1da177e4 LT |
1057 | if (!filp) |
1058 | goto out_unlock; | |
ab2af1f5 | 1059 | rcu_assign_pointer(fdt->fd[fd], NULL); |
badf1662 | 1060 | FD_CLR(fd, fdt->close_on_exec); |
1da177e4 LT |
1061 | __put_unused_fd(files, fd); |
1062 | spin_unlock(&files->file_lock); | |
ee731f4f EP |
1063 | retval = filp_close(filp, files); |
1064 | ||
1065 | /* can't restart close syscall because file table entry was cleared */ | |
1066 | if (unlikely(retval == -ERESTARTSYS || | |
1067 | retval == -ERESTARTNOINTR || | |
1068 | retval == -ERESTARTNOHAND || | |
1069 | retval == -ERESTART_RESTARTBLOCK)) | |
1070 | retval = -EINTR; | |
1071 | ||
1072 | return retval; | |
1da177e4 LT |
1073 | |
1074 | out_unlock: | |
1075 | spin_unlock(&files->file_lock); | |
1076 | return -EBADF; | |
1077 | } | |
1078 | ||
1079 | EXPORT_SYMBOL(sys_close); | |
1080 | ||
1081 | /* | |
1082 | * This routine simulates a hangup on the tty, to arrange that users | |
1083 | * are given clean terminals at login time. | |
1084 | */ | |
1085 | asmlinkage long sys_vhangup(void) | |
1086 | { | |
1087 | if (capable(CAP_SYS_TTY_CONFIG)) { | |
24ec839c | 1088 | /* XXX: this needs locking */ |
1da177e4 LT |
1089 | tty_vhangup(current->signal->tty); |
1090 | return 0; | |
1091 | } | |
1092 | return -EPERM; | |
1093 | } | |
1094 | ||
1095 | /* | |
1096 | * Called when an inode is about to be open. | |
1097 | * We use this to disallow opening large files on 32bit systems if | |
1098 | * the caller didn't specify O_LARGEFILE. On 64bit systems we force | |
1099 | * on this flag in sys_open. | |
1100 | */ | |
1101 | int generic_file_open(struct inode * inode, struct file * filp) | |
1102 | { | |
1103 | if (!(filp->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS) | |
1104 | return -EFBIG; | |
1105 | return 0; | |
1106 | } | |
1107 | ||
1108 | EXPORT_SYMBOL(generic_file_open); | |
1109 | ||
1110 | /* | |
1111 | * This is used by subsystems that don't want seekable | |
1112 | * file descriptors | |
1113 | */ | |
1114 | int nonseekable_open(struct inode *inode, struct file *filp) | |
1115 | { | |
1116 | filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE); | |
1117 | return 0; | |
1118 | } | |
1119 | ||
1120 | EXPORT_SYMBOL(nonseekable_open); |