diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /fs/open.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'fs/open.c')
-rw-r--r-- | fs/open.c | 1076 |
1 files changed, 1076 insertions, 0 deletions
diff --git a/fs/open.c b/fs/open.c new file mode 100644 index 000000000000..963bd81a44c8 --- /dev/null +++ b/fs/open.c | |||
@@ -0,0 +1,1076 @@ | |||
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> | ||
13 | #include <linux/dnotify.h> | ||
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> | ||
24 | #include <linux/pagemap.h> | ||
25 | #include <linux/syscalls.h> | ||
26 | |||
27 | #include <asm/unistd.h> | ||
28 | |||
29 | int vfs_statfs(struct super_block *sb, struct kstatfs *buf) | ||
30 | { | ||
31 | int retval = -ENODEV; | ||
32 | |||
33 | if (sb) { | ||
34 | retval = -ENOSYS; | ||
35 | if (sb->s_op->statfs) { | ||
36 | memset(buf, 0, sizeof(*buf)); | ||
37 | retval = security_sb_statfs(sb); | ||
38 | if (retval) | ||
39 | return retval; | ||
40 | retval = sb->s_op->statfs(sb, buf); | ||
41 | if (retval == 0 && buf->f_frsize == 0) | ||
42 | buf->f_frsize = buf->f_bsize; | ||
43 | } | ||
44 | } | ||
45 | return retval; | ||
46 | } | ||
47 | |||
48 | EXPORT_SYMBOL(vfs_statfs); | ||
49 | |||
50 | static int vfs_statfs_native(struct super_block *sb, struct statfs *buf) | ||
51 | { | ||
52 | struct kstatfs st; | ||
53 | int retval; | ||
54 | |||
55 | retval = vfs_statfs(sb, &st); | ||
56 | if (retval) | ||
57 | return retval; | ||
58 | |||
59 | if (sizeof(*buf) == sizeof(st)) | ||
60 | memcpy(buf, &st, sizeof(st)); | ||
61 | else { | ||
62 | if (sizeof buf->f_blocks == 4) { | ||
63 | if ((st.f_blocks | st.f_bfree | st.f_bavail) & | ||
64 | 0xffffffff00000000ULL) | ||
65 | return -EOVERFLOW; | ||
66 | /* | ||
67 | * f_files and f_ffree may be -1; it's okay to stuff | ||
68 | * that into 32 bits | ||
69 | */ | ||
70 | if (st.f_files != -1 && | ||
71 | (st.f_files & 0xffffffff00000000ULL)) | ||
72 | return -EOVERFLOW; | ||
73 | if (st.f_ffree != -1 && | ||
74 | (st.f_ffree & 0xffffffff00000000ULL)) | ||
75 | return -EOVERFLOW; | ||
76 | } | ||
77 | |||
78 | buf->f_type = st.f_type; | ||
79 | buf->f_bsize = st.f_bsize; | ||
80 | buf->f_blocks = st.f_blocks; | ||
81 | buf->f_bfree = st.f_bfree; | ||
82 | buf->f_bavail = st.f_bavail; | ||
83 | buf->f_files = st.f_files; | ||
84 | buf->f_ffree = st.f_ffree; | ||
85 | buf->f_fsid = st.f_fsid; | ||
86 | buf->f_namelen = st.f_namelen; | ||
87 | buf->f_frsize = st.f_frsize; | ||
88 | memset(buf->f_spare, 0, sizeof(buf->f_spare)); | ||
89 | } | ||
90 | return 0; | ||
91 | } | ||
92 | |||
93 | static int vfs_statfs64(struct super_block *sb, struct statfs64 *buf) | ||
94 | { | ||
95 | struct kstatfs st; | ||
96 | int retval; | ||
97 | |||
98 | retval = vfs_statfs(sb, &st); | ||
99 | if (retval) | ||
100 | return retval; | ||
101 | |||
102 | if (sizeof(*buf) == sizeof(st)) | ||
103 | memcpy(buf, &st, sizeof(st)); | ||
104 | else { | ||
105 | buf->f_type = st.f_type; | ||
106 | buf->f_bsize = st.f_bsize; | ||
107 | buf->f_blocks = st.f_blocks; | ||
108 | buf->f_bfree = st.f_bfree; | ||
109 | buf->f_bavail = st.f_bavail; | ||
110 | buf->f_files = st.f_files; | ||
111 | buf->f_ffree = st.f_ffree; | ||
112 | buf->f_fsid = st.f_fsid; | ||
113 | buf->f_namelen = st.f_namelen; | ||
114 | buf->f_frsize = st.f_frsize; | ||
115 | memset(buf->f_spare, 0, sizeof(buf->f_spare)); | ||
116 | } | ||
117 | return 0; | ||
118 | } | ||
119 | |||
120 | asmlinkage long sys_statfs(const char __user * path, struct statfs __user * buf) | ||
121 | { | ||
122 | struct nameidata nd; | ||
123 | int error; | ||
124 | |||
125 | error = user_path_walk(path, &nd); | ||
126 | if (!error) { | ||
127 | struct statfs tmp; | ||
128 | error = vfs_statfs_native(nd.dentry->d_inode->i_sb, &tmp); | ||
129 | if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) | ||
130 | error = -EFAULT; | ||
131 | path_release(&nd); | ||
132 | } | ||
133 | return error; | ||
134 | } | ||
135 | |||
136 | |||
137 | asmlinkage long sys_statfs64(const char __user *path, size_t sz, struct statfs64 __user *buf) | ||
138 | { | ||
139 | struct nameidata nd; | ||
140 | long error; | ||
141 | |||
142 | if (sz != sizeof(*buf)) | ||
143 | return -EINVAL; | ||
144 | error = user_path_walk(path, &nd); | ||
145 | if (!error) { | ||
146 | struct statfs64 tmp; | ||
147 | error = vfs_statfs64(nd.dentry->d_inode->i_sb, &tmp); | ||
148 | if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) | ||
149 | error = -EFAULT; | ||
150 | path_release(&nd); | ||
151 | } | ||
152 | return error; | ||
153 | } | ||
154 | |||
155 | |||
156 | asmlinkage long sys_fstatfs(unsigned int fd, struct statfs __user * buf) | ||
157 | { | ||
158 | struct file * file; | ||
159 | struct statfs tmp; | ||
160 | int error; | ||
161 | |||
162 | error = -EBADF; | ||
163 | file = fget(fd); | ||
164 | if (!file) | ||
165 | goto out; | ||
166 | error = vfs_statfs_native(file->f_dentry->d_inode->i_sb, &tmp); | ||
167 | if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) | ||
168 | error = -EFAULT; | ||
169 | fput(file); | ||
170 | out: | ||
171 | return error; | ||
172 | } | ||
173 | |||
174 | asmlinkage long sys_fstatfs64(unsigned int fd, size_t sz, struct statfs64 __user *buf) | ||
175 | { | ||
176 | struct file * file; | ||
177 | struct statfs64 tmp; | ||
178 | int error; | ||
179 | |||
180 | if (sz != sizeof(*buf)) | ||
181 | return -EINVAL; | ||
182 | |||
183 | error = -EBADF; | ||
184 | file = fget(fd); | ||
185 | if (!file) | ||
186 | goto out; | ||
187 | error = vfs_statfs64(file->f_dentry->d_inode->i_sb, &tmp); | ||
188 | if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) | ||
189 | error = -EFAULT; | ||
190 | fput(file); | ||
191 | out: | ||
192 | return error; | ||
193 | } | ||
194 | |||
195 | int do_truncate(struct dentry *dentry, loff_t length) | ||
196 | { | ||
197 | int err; | ||
198 | struct iattr newattrs; | ||
199 | |||
200 | /* Not pretty: "inode->i_size" shouldn't really be signed. But it is. */ | ||
201 | if (length < 0) | ||
202 | return -EINVAL; | ||
203 | |||
204 | newattrs.ia_size = length; | ||
205 | newattrs.ia_valid = ATTR_SIZE | ATTR_CTIME; | ||
206 | |||
207 | down(&dentry->d_inode->i_sem); | ||
208 | err = notify_change(dentry, &newattrs); | ||
209 | up(&dentry->d_inode->i_sem); | ||
210 | return err; | ||
211 | } | ||
212 | |||
213 | static inline long do_sys_truncate(const char __user * path, loff_t length) | ||
214 | { | ||
215 | struct nameidata nd; | ||
216 | struct inode * inode; | ||
217 | int error; | ||
218 | |||
219 | error = -EINVAL; | ||
220 | if (length < 0) /* sorry, but loff_t says... */ | ||
221 | goto out; | ||
222 | |||
223 | error = user_path_walk(path, &nd); | ||
224 | if (error) | ||
225 | goto out; | ||
226 | inode = nd.dentry->d_inode; | ||
227 | |||
228 | /* For directories it's -EISDIR, for other non-regulars - -EINVAL */ | ||
229 | error = -EISDIR; | ||
230 | if (S_ISDIR(inode->i_mode)) | ||
231 | goto dput_and_out; | ||
232 | |||
233 | error = -EINVAL; | ||
234 | if (!S_ISREG(inode->i_mode)) | ||
235 | goto dput_and_out; | ||
236 | |||
237 | error = permission(inode,MAY_WRITE,&nd); | ||
238 | if (error) | ||
239 | goto dput_and_out; | ||
240 | |||
241 | error = -EROFS; | ||
242 | if (IS_RDONLY(inode)) | ||
243 | goto dput_and_out; | ||
244 | |||
245 | error = -EPERM; | ||
246 | if (IS_IMMUTABLE(inode) || IS_APPEND(inode)) | ||
247 | goto dput_and_out; | ||
248 | |||
249 | /* | ||
250 | * Make sure that there are no leases. | ||
251 | */ | ||
252 | error = break_lease(inode, FMODE_WRITE); | ||
253 | if (error) | ||
254 | goto dput_and_out; | ||
255 | |||
256 | error = get_write_access(inode); | ||
257 | if (error) | ||
258 | goto dput_and_out; | ||
259 | |||
260 | error = locks_verify_truncate(inode, NULL, length); | ||
261 | if (!error) { | ||
262 | DQUOT_INIT(inode); | ||
263 | error = do_truncate(nd.dentry, length); | ||
264 | } | ||
265 | put_write_access(inode); | ||
266 | |||
267 | dput_and_out: | ||
268 | path_release(&nd); | ||
269 | out: | ||
270 | return error; | ||
271 | } | ||
272 | |||
273 | asmlinkage long sys_truncate(const char __user * path, unsigned long length) | ||
274 | { | ||
275 | /* on 32-bit boxen it will cut the range 2^31--2^32-1 off */ | ||
276 | return do_sys_truncate(path, (long)length); | ||
277 | } | ||
278 | |||
279 | static inline long do_sys_ftruncate(unsigned int fd, loff_t length, int small) | ||
280 | { | ||
281 | struct inode * inode; | ||
282 | struct dentry *dentry; | ||
283 | struct file * file; | ||
284 | int error; | ||
285 | |||
286 | error = -EINVAL; | ||
287 | if (length < 0) | ||
288 | goto out; | ||
289 | error = -EBADF; | ||
290 | file = fget(fd); | ||
291 | if (!file) | ||
292 | goto out; | ||
293 | |||
294 | /* explicitly opened as large or we are on 64-bit box */ | ||
295 | if (file->f_flags & O_LARGEFILE) | ||
296 | small = 0; | ||
297 | |||
298 | dentry = file->f_dentry; | ||
299 | inode = dentry->d_inode; | ||
300 | error = -EINVAL; | ||
301 | if (!S_ISREG(inode->i_mode) || !(file->f_mode & FMODE_WRITE)) | ||
302 | goto out_putf; | ||
303 | |||
304 | error = -EINVAL; | ||
305 | /* Cannot ftruncate over 2^31 bytes without large file support */ | ||
306 | if (small && length > MAX_NON_LFS) | ||
307 | goto out_putf; | ||
308 | |||
309 | error = -EPERM; | ||
310 | if (IS_APPEND(inode)) | ||
311 | goto out_putf; | ||
312 | |||
313 | error = locks_verify_truncate(inode, file, length); | ||
314 | if (!error) | ||
315 | error = do_truncate(dentry, length); | ||
316 | out_putf: | ||
317 | fput(file); | ||
318 | out: | ||
319 | return error; | ||
320 | } | ||
321 | |||
322 | asmlinkage long sys_ftruncate(unsigned int fd, unsigned long length) | ||
323 | { | ||
324 | return do_sys_ftruncate(fd, length, 1); | ||
325 | } | ||
326 | |||
327 | /* LFS versions of truncate are only needed on 32 bit machines */ | ||
328 | #if BITS_PER_LONG == 32 | ||
329 | asmlinkage long sys_truncate64(const char __user * path, loff_t length) | ||
330 | { | ||
331 | return do_sys_truncate(path, length); | ||
332 | } | ||
333 | |||
334 | asmlinkage long sys_ftruncate64(unsigned int fd, loff_t length) | ||
335 | { | ||
336 | return do_sys_ftruncate(fd, length, 0); | ||
337 | } | ||
338 | #endif | ||
339 | |||
340 | #ifdef __ARCH_WANT_SYS_UTIME | ||
341 | |||
342 | /* | ||
343 | * sys_utime() can be implemented in user-level using sys_utimes(). | ||
344 | * Is this for backwards compatibility? If so, why not move it | ||
345 | * into the appropriate arch directory (for those architectures that | ||
346 | * need it). | ||
347 | */ | ||
348 | |||
349 | /* If times==NULL, set access and modification to current time, | ||
350 | * must be owner or have write permission. | ||
351 | * Else, update from *times, must be owner or super user. | ||
352 | */ | ||
353 | asmlinkage long sys_utime(char __user * filename, struct utimbuf __user * times) | ||
354 | { | ||
355 | int error; | ||
356 | struct nameidata nd; | ||
357 | struct inode * inode; | ||
358 | struct iattr newattrs; | ||
359 | |||
360 | error = user_path_walk(filename, &nd); | ||
361 | if (error) | ||
362 | goto out; | ||
363 | inode = nd.dentry->d_inode; | ||
364 | |||
365 | error = -EROFS; | ||
366 | if (IS_RDONLY(inode)) | ||
367 | goto dput_and_out; | ||
368 | |||
369 | /* Don't worry, the checks are done in inode_change_ok() */ | ||
370 | newattrs.ia_valid = ATTR_CTIME | ATTR_MTIME | ATTR_ATIME; | ||
371 | if (times) { | ||
372 | error = -EPERM; | ||
373 | if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) | ||
374 | goto dput_and_out; | ||
375 | |||
376 | error = get_user(newattrs.ia_atime.tv_sec, ×->actime); | ||
377 | newattrs.ia_atime.tv_nsec = 0; | ||
378 | if (!error) | ||
379 | error = get_user(newattrs.ia_mtime.tv_sec, ×->modtime); | ||
380 | newattrs.ia_mtime.tv_nsec = 0; | ||
381 | if (error) | ||
382 | goto dput_and_out; | ||
383 | |||
384 | newattrs.ia_valid |= ATTR_ATIME_SET | ATTR_MTIME_SET; | ||
385 | } else { | ||
386 | error = -EACCES; | ||
387 | if (IS_IMMUTABLE(inode)) | ||
388 | goto dput_and_out; | ||
389 | |||
390 | if (current->fsuid != inode->i_uid && | ||
391 | (error = permission(inode,MAY_WRITE,&nd)) != 0) | ||
392 | goto dput_and_out; | ||
393 | } | ||
394 | down(&inode->i_sem); | ||
395 | error = notify_change(nd.dentry, &newattrs); | ||
396 | up(&inode->i_sem); | ||
397 | dput_and_out: | ||
398 | path_release(&nd); | ||
399 | out: | ||
400 | return error; | ||
401 | } | ||
402 | |||
403 | #endif | ||
404 | |||
405 | /* If times==NULL, set access and modification to current time, | ||
406 | * must be owner or have write permission. | ||
407 | * Else, update from *times, must be owner or super user. | ||
408 | */ | ||
409 | long do_utimes(char __user * filename, struct timeval * times) | ||
410 | { | ||
411 | int error; | ||
412 | struct nameidata nd; | ||
413 | struct inode * inode; | ||
414 | struct iattr newattrs; | ||
415 | |||
416 | error = user_path_walk(filename, &nd); | ||
417 | |||
418 | if (error) | ||
419 | goto out; | ||
420 | inode = nd.dentry->d_inode; | ||
421 | |||
422 | error = -EROFS; | ||
423 | if (IS_RDONLY(inode)) | ||
424 | goto dput_and_out; | ||
425 | |||
426 | /* Don't worry, the checks are done in inode_change_ok() */ | ||
427 | newattrs.ia_valid = ATTR_CTIME | ATTR_MTIME | ATTR_ATIME; | ||
428 | if (times) { | ||
429 | error = -EPERM; | ||
430 | if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) | ||
431 | goto dput_and_out; | ||
432 | |||
433 | newattrs.ia_atime.tv_sec = times[0].tv_sec; | ||
434 | newattrs.ia_atime.tv_nsec = times[0].tv_usec * 1000; | ||
435 | newattrs.ia_mtime.tv_sec = times[1].tv_sec; | ||
436 | newattrs.ia_mtime.tv_nsec = times[1].tv_usec * 1000; | ||
437 | newattrs.ia_valid |= ATTR_ATIME_SET | ATTR_MTIME_SET; | ||
438 | } else { | ||
439 | error = -EACCES; | ||
440 | if (IS_IMMUTABLE(inode)) | ||
441 | goto dput_and_out; | ||
442 | |||
443 | if (current->fsuid != inode->i_uid && | ||
444 | (error = permission(inode,MAY_WRITE,&nd)) != 0) | ||
445 | goto dput_and_out; | ||
446 | } | ||
447 | down(&inode->i_sem); | ||
448 | error = notify_change(nd.dentry, &newattrs); | ||
449 | up(&inode->i_sem); | ||
450 | dput_and_out: | ||
451 | path_release(&nd); | ||
452 | out: | ||
453 | return error; | ||
454 | } | ||
455 | |||
456 | asmlinkage long sys_utimes(char __user * filename, struct timeval __user * utimes) | ||
457 | { | ||
458 | struct timeval times[2]; | ||
459 | |||
460 | if (utimes && copy_from_user(×, utimes, sizeof(times))) | ||
461 | return -EFAULT; | ||
462 | return do_utimes(filename, utimes ? times : NULL); | ||
463 | } | ||
464 | |||
465 | |||
466 | /* | ||
467 | * access() needs to use the real uid/gid, not the effective uid/gid. | ||
468 | * We do this by temporarily clearing all FS-related capabilities and | ||
469 | * switching the fsuid/fsgid around to the real ones. | ||
470 | */ | ||
471 | asmlinkage long sys_access(const char __user * filename, int mode) | ||
472 | { | ||
473 | struct nameidata nd; | ||
474 | int old_fsuid, old_fsgid; | ||
475 | kernel_cap_t old_cap; | ||
476 | int res; | ||
477 | |||
478 | if (mode & ~S_IRWXO) /* where's F_OK, X_OK, W_OK, R_OK? */ | ||
479 | return -EINVAL; | ||
480 | |||
481 | old_fsuid = current->fsuid; | ||
482 | old_fsgid = current->fsgid; | ||
483 | old_cap = current->cap_effective; | ||
484 | |||
485 | current->fsuid = current->uid; | ||
486 | current->fsgid = current->gid; | ||
487 | |||
488 | /* | ||
489 | * Clear the capabilities if we switch to a non-root user | ||
490 | * | ||
491 | * FIXME: There is a race here against sys_capset. The | ||
492 | * capabilities can change yet we will restore the old | ||
493 | * value below. We should hold task_capabilities_lock, | ||
494 | * but we cannot because user_path_walk can sleep. | ||
495 | */ | ||
496 | if (current->uid) | ||
497 | cap_clear(current->cap_effective); | ||
498 | else | ||
499 | current->cap_effective = current->cap_permitted; | ||
500 | |||
501 | res = __user_walk(filename, LOOKUP_FOLLOW|LOOKUP_ACCESS, &nd); | ||
502 | if (!res) { | ||
503 | res = permission(nd.dentry->d_inode, mode, &nd); | ||
504 | /* SuS v2 requires we report a read only fs too */ | ||
505 | if(!res && (mode & S_IWOTH) && IS_RDONLY(nd.dentry->d_inode) | ||
506 | && !special_file(nd.dentry->d_inode->i_mode)) | ||
507 | res = -EROFS; | ||
508 | path_release(&nd); | ||
509 | } | ||
510 | |||
511 | current->fsuid = old_fsuid; | ||
512 | current->fsgid = old_fsgid; | ||
513 | current->cap_effective = old_cap; | ||
514 | |||
515 | return res; | ||
516 | } | ||
517 | |||
518 | asmlinkage long sys_chdir(const char __user * filename) | ||
519 | { | ||
520 | struct nameidata nd; | ||
521 | int error; | ||
522 | |||
523 | error = __user_walk(filename, LOOKUP_FOLLOW|LOOKUP_DIRECTORY, &nd); | ||
524 | if (error) | ||
525 | goto out; | ||
526 | |||
527 | error = permission(nd.dentry->d_inode,MAY_EXEC,&nd); | ||
528 | if (error) | ||
529 | goto dput_and_out; | ||
530 | |||
531 | set_fs_pwd(current->fs, nd.mnt, nd.dentry); | ||
532 | |||
533 | dput_and_out: | ||
534 | path_release(&nd); | ||
535 | out: | ||
536 | return error; | ||
537 | } | ||
538 | |||
539 | asmlinkage long sys_fchdir(unsigned int fd) | ||
540 | { | ||
541 | struct file *file; | ||
542 | struct dentry *dentry; | ||
543 | struct inode *inode; | ||
544 | struct vfsmount *mnt; | ||
545 | int error; | ||
546 | |||
547 | error = -EBADF; | ||
548 | file = fget(fd); | ||
549 | if (!file) | ||
550 | goto out; | ||
551 | |||
552 | dentry = file->f_dentry; | ||
553 | mnt = file->f_vfsmnt; | ||
554 | inode = dentry->d_inode; | ||
555 | |||
556 | error = -ENOTDIR; | ||
557 | if (!S_ISDIR(inode->i_mode)) | ||
558 | goto out_putf; | ||
559 | |||
560 | error = permission(inode, MAY_EXEC, NULL); | ||
561 | if (!error) | ||
562 | set_fs_pwd(current->fs, mnt, dentry); | ||
563 | out_putf: | ||
564 | fput(file); | ||
565 | out: | ||
566 | return error; | ||
567 | } | ||
568 | |||
569 | asmlinkage long sys_chroot(const char __user * filename) | ||
570 | { | ||
571 | struct nameidata nd; | ||
572 | int error; | ||
573 | |||
574 | error = __user_walk(filename, LOOKUP_FOLLOW | LOOKUP_DIRECTORY | LOOKUP_NOALT, &nd); | ||
575 | if (error) | ||
576 | goto out; | ||
577 | |||
578 | error = permission(nd.dentry->d_inode,MAY_EXEC,&nd); | ||
579 | if (error) | ||
580 | goto dput_and_out; | ||
581 | |||
582 | error = -EPERM; | ||
583 | if (!capable(CAP_SYS_CHROOT)) | ||
584 | goto dput_and_out; | ||
585 | |||
586 | set_fs_root(current->fs, nd.mnt, nd.dentry); | ||
587 | set_fs_altroot(); | ||
588 | error = 0; | ||
589 | dput_and_out: | ||
590 | path_release(&nd); | ||
591 | out: | ||
592 | return error; | ||
593 | } | ||
594 | |||
595 | asmlinkage long sys_fchmod(unsigned int fd, mode_t mode) | ||
596 | { | ||
597 | struct inode * inode; | ||
598 | struct dentry * dentry; | ||
599 | struct file * file; | ||
600 | int err = -EBADF; | ||
601 | struct iattr newattrs; | ||
602 | |||
603 | file = fget(fd); | ||
604 | if (!file) | ||
605 | goto out; | ||
606 | |||
607 | dentry = file->f_dentry; | ||
608 | inode = dentry->d_inode; | ||
609 | |||
610 | err = -EROFS; | ||
611 | if (IS_RDONLY(inode)) | ||
612 | goto out_putf; | ||
613 | err = -EPERM; | ||
614 | if (IS_IMMUTABLE(inode) || IS_APPEND(inode)) | ||
615 | goto out_putf; | ||
616 | down(&inode->i_sem); | ||
617 | if (mode == (mode_t) -1) | ||
618 | mode = inode->i_mode; | ||
619 | newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO); | ||
620 | newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; | ||
621 | err = notify_change(dentry, &newattrs); | ||
622 | up(&inode->i_sem); | ||
623 | |||
624 | out_putf: | ||
625 | fput(file); | ||
626 | out: | ||
627 | return err; | ||
628 | } | ||
629 | |||
630 | asmlinkage long sys_chmod(const char __user * filename, mode_t mode) | ||
631 | { | ||
632 | struct nameidata nd; | ||
633 | struct inode * inode; | ||
634 | int error; | ||
635 | struct iattr newattrs; | ||
636 | |||
637 | error = user_path_walk(filename, &nd); | ||
638 | if (error) | ||
639 | goto out; | ||
640 | inode = nd.dentry->d_inode; | ||
641 | |||
642 | error = -EROFS; | ||
643 | if (IS_RDONLY(inode)) | ||
644 | goto dput_and_out; | ||
645 | |||
646 | error = -EPERM; | ||
647 | if (IS_IMMUTABLE(inode) || IS_APPEND(inode)) | ||
648 | goto dput_and_out; | ||
649 | |||
650 | down(&inode->i_sem); | ||
651 | if (mode == (mode_t) -1) | ||
652 | mode = inode->i_mode; | ||
653 | newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO); | ||
654 | newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; | ||
655 | error = notify_change(nd.dentry, &newattrs); | ||
656 | up(&inode->i_sem); | ||
657 | |||
658 | dput_and_out: | ||
659 | path_release(&nd); | ||
660 | out: | ||
661 | return error; | ||
662 | } | ||
663 | |||
664 | static int chown_common(struct dentry * dentry, uid_t user, gid_t group) | ||
665 | { | ||
666 | struct inode * inode; | ||
667 | int error; | ||
668 | struct iattr newattrs; | ||
669 | |||
670 | error = -ENOENT; | ||
671 | if (!(inode = dentry->d_inode)) { | ||
672 | printk(KERN_ERR "chown_common: NULL inode\n"); | ||
673 | goto out; | ||
674 | } | ||
675 | error = -EROFS; | ||
676 | if (IS_RDONLY(inode)) | ||
677 | goto out; | ||
678 | error = -EPERM; | ||
679 | if (IS_IMMUTABLE(inode) || IS_APPEND(inode)) | ||
680 | goto out; | ||
681 | newattrs.ia_valid = ATTR_CTIME; | ||
682 | if (user != (uid_t) -1) { | ||
683 | newattrs.ia_valid |= ATTR_UID; | ||
684 | newattrs.ia_uid = user; | ||
685 | } | ||
686 | if (group != (gid_t) -1) { | ||
687 | newattrs.ia_valid |= ATTR_GID; | ||
688 | newattrs.ia_gid = group; | ||
689 | } | ||
690 | if (!S_ISDIR(inode->i_mode)) | ||
691 | newattrs.ia_valid |= ATTR_KILL_SUID|ATTR_KILL_SGID; | ||
692 | down(&inode->i_sem); | ||
693 | error = notify_change(dentry, &newattrs); | ||
694 | up(&inode->i_sem); | ||
695 | out: | ||
696 | return error; | ||
697 | } | ||
698 | |||
699 | asmlinkage long sys_chown(const char __user * filename, uid_t user, gid_t group) | ||
700 | { | ||
701 | struct nameidata nd; | ||
702 | int error; | ||
703 | |||
704 | error = user_path_walk(filename, &nd); | ||
705 | if (!error) { | ||
706 | error = chown_common(nd.dentry, user, group); | ||
707 | path_release(&nd); | ||
708 | } | ||
709 | return error; | ||
710 | } | ||
711 | |||
712 | asmlinkage long sys_lchown(const char __user * filename, uid_t user, gid_t group) | ||
713 | { | ||
714 | struct nameidata nd; | ||
715 | int error; | ||
716 | |||
717 | error = user_path_walk_link(filename, &nd); | ||
718 | if (!error) { | ||
719 | error = chown_common(nd.dentry, user, group); | ||
720 | path_release(&nd); | ||
721 | } | ||
722 | return error; | ||
723 | } | ||
724 | |||
725 | |||
726 | asmlinkage long sys_fchown(unsigned int fd, uid_t user, gid_t group) | ||
727 | { | ||
728 | struct file * file; | ||
729 | int error = -EBADF; | ||
730 | |||
731 | file = fget(fd); | ||
732 | if (file) { | ||
733 | error = chown_common(file->f_dentry, user, group); | ||
734 | fput(file); | ||
735 | } | ||
736 | return error; | ||
737 | } | ||
738 | |||
739 | /* | ||
740 | * Note that while the flag value (low two bits) for sys_open means: | ||
741 | * 00 - read-only | ||
742 | * 01 - write-only | ||
743 | * 10 - read-write | ||
744 | * 11 - special | ||
745 | * it is changed into | ||
746 | * 00 - no permissions needed | ||
747 | * 01 - read-permission | ||
748 | * 10 - write-permission | ||
749 | * 11 - read-write | ||
750 | * for the internal routines (ie open_namei()/follow_link() etc). 00 is | ||
751 | * used by symlinks. | ||
752 | */ | ||
753 | struct file *filp_open(const char * filename, int flags, int mode) | ||
754 | { | ||
755 | int namei_flags, error; | ||
756 | struct nameidata nd; | ||
757 | |||
758 | namei_flags = flags; | ||
759 | if ((namei_flags+1) & O_ACCMODE) | ||
760 | namei_flags++; | ||
761 | if (namei_flags & O_TRUNC) | ||
762 | namei_flags |= 2; | ||
763 | |||
764 | error = open_namei(filename, namei_flags, mode, &nd); | ||
765 | if (!error) | ||
766 | return dentry_open(nd.dentry, nd.mnt, flags); | ||
767 | |||
768 | return ERR_PTR(error); | ||
769 | } | ||
770 | |||
771 | EXPORT_SYMBOL(filp_open); | ||
772 | |||
773 | struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags) | ||
774 | { | ||
775 | struct file * f; | ||
776 | struct inode *inode; | ||
777 | int error; | ||
778 | |||
779 | error = -ENFILE; | ||
780 | f = get_empty_filp(); | ||
781 | if (!f) | ||
782 | goto cleanup_dentry; | ||
783 | f->f_flags = flags; | ||
784 | f->f_mode = ((flags+1) & O_ACCMODE) | FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE; | ||
785 | inode = dentry->d_inode; | ||
786 | if (f->f_mode & FMODE_WRITE) { | ||
787 | error = get_write_access(inode); | ||
788 | if (error) | ||
789 | goto cleanup_file; | ||
790 | } | ||
791 | |||
792 | f->f_mapping = inode->i_mapping; | ||
793 | f->f_dentry = dentry; | ||
794 | f->f_vfsmnt = mnt; | ||
795 | f->f_pos = 0; | ||
796 | f->f_op = fops_get(inode->i_fop); | ||
797 | file_move(f, &inode->i_sb->s_files); | ||
798 | |||
799 | if (f->f_op && f->f_op->open) { | ||
800 | error = f->f_op->open(inode,f); | ||
801 | if (error) | ||
802 | goto cleanup_all; | ||
803 | } | ||
804 | f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC); | ||
805 | |||
806 | file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping); | ||
807 | |||
808 | /* NB: we're sure to have correct a_ops only after f_op->open */ | ||
809 | if (f->f_flags & O_DIRECT) { | ||
810 | if (!f->f_mapping->a_ops || !f->f_mapping->a_ops->direct_IO) { | ||
811 | fput(f); | ||
812 | f = ERR_PTR(-EINVAL); | ||
813 | } | ||
814 | } | ||
815 | |||
816 | return f; | ||
817 | |||
818 | cleanup_all: | ||
819 | fops_put(f->f_op); | ||
820 | if (f->f_mode & FMODE_WRITE) | ||
821 | put_write_access(inode); | ||
822 | file_kill(f); | ||
823 | f->f_dentry = NULL; | ||
824 | f->f_vfsmnt = NULL; | ||
825 | cleanup_file: | ||
826 | put_filp(f); | ||
827 | cleanup_dentry: | ||
828 | dput(dentry); | ||
829 | mntput(mnt); | ||
830 | return ERR_PTR(error); | ||
831 | } | ||
832 | |||
833 | EXPORT_SYMBOL(dentry_open); | ||
834 | |||
835 | /* | ||
836 | * Find an empty file descriptor entry, and mark it busy. | ||
837 | */ | ||
838 | int get_unused_fd(void) | ||
839 | { | ||
840 | struct files_struct * files = current->files; | ||
841 | int fd, error; | ||
842 | |||
843 | error = -EMFILE; | ||
844 | spin_lock(&files->file_lock); | ||
845 | |||
846 | repeat: | ||
847 | fd = find_next_zero_bit(files->open_fds->fds_bits, | ||
848 | files->max_fdset, | ||
849 | files->next_fd); | ||
850 | |||
851 | /* | ||
852 | * N.B. For clone tasks sharing a files structure, this test | ||
853 | * will limit the total number of files that can be opened. | ||
854 | */ | ||
855 | if (fd >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur) | ||
856 | goto out; | ||
857 | |||
858 | /* Do we need to expand the fd array or fd set? */ | ||
859 | error = expand_files(files, fd); | ||
860 | if (error < 0) | ||
861 | goto out; | ||
862 | |||
863 | if (error) { | ||
864 | /* | ||
865 | * If we needed to expand the fs array we | ||
866 | * might have blocked - try again. | ||
867 | */ | ||
868 | error = -EMFILE; | ||
869 | goto repeat; | ||
870 | } | ||
871 | |||
872 | FD_SET(fd, files->open_fds); | ||
873 | FD_CLR(fd, files->close_on_exec); | ||
874 | files->next_fd = fd + 1; | ||
875 | #if 1 | ||
876 | /* Sanity check */ | ||
877 | if (files->fd[fd] != NULL) { | ||
878 | printk(KERN_WARNING "get_unused_fd: slot %d not NULL!\n", fd); | ||
879 | files->fd[fd] = NULL; | ||
880 | } | ||
881 | #endif | ||
882 | error = fd; | ||
883 | |||
884 | out: | ||
885 | spin_unlock(&files->file_lock); | ||
886 | return error; | ||
887 | } | ||
888 | |||
889 | EXPORT_SYMBOL(get_unused_fd); | ||
890 | |||
891 | static inline void __put_unused_fd(struct files_struct *files, unsigned int fd) | ||
892 | { | ||
893 | __FD_CLR(fd, files->open_fds); | ||
894 | if (fd < files->next_fd) | ||
895 | files->next_fd = fd; | ||
896 | } | ||
897 | |||
898 | void fastcall put_unused_fd(unsigned int fd) | ||
899 | { | ||
900 | struct files_struct *files = current->files; | ||
901 | spin_lock(&files->file_lock); | ||
902 | __put_unused_fd(files, fd); | ||
903 | spin_unlock(&files->file_lock); | ||
904 | } | ||
905 | |||
906 | EXPORT_SYMBOL(put_unused_fd); | ||
907 | |||
908 | /* | ||
909 | * Install a file pointer in the fd array. | ||
910 | * | ||
911 | * The VFS is full of places where we drop the files lock between | ||
912 | * setting the open_fds bitmap and installing the file in the file | ||
913 | * array. At any such point, we are vulnerable to a dup2() race | ||
914 | * installing a file in the array before us. We need to detect this and | ||
915 | * fput() the struct file we are about to overwrite in this case. | ||
916 | * | ||
917 | * It should never happen - if we allow dup2() do it, _really_ bad things | ||
918 | * will follow. | ||
919 | */ | ||
920 | |||
921 | void fastcall fd_install(unsigned int fd, struct file * file) | ||
922 | { | ||
923 | struct files_struct *files = current->files; | ||
924 | spin_lock(&files->file_lock); | ||
925 | if (unlikely(files->fd[fd] != NULL)) | ||
926 | BUG(); | ||
927 | files->fd[fd] = file; | ||
928 | spin_unlock(&files->file_lock); | ||
929 | } | ||
930 | |||
931 | EXPORT_SYMBOL(fd_install); | ||
932 | |||
933 | asmlinkage long sys_open(const char __user * filename, int flags, int mode) | ||
934 | { | ||
935 | char * tmp; | ||
936 | int fd, error; | ||
937 | |||
938 | #if BITS_PER_LONG != 32 | ||
939 | flags |= O_LARGEFILE; | ||
940 | #endif | ||
941 | tmp = getname(filename); | ||
942 | fd = PTR_ERR(tmp); | ||
943 | if (!IS_ERR(tmp)) { | ||
944 | fd = get_unused_fd(); | ||
945 | if (fd >= 0) { | ||
946 | struct file *f = filp_open(tmp, flags, mode); | ||
947 | error = PTR_ERR(f); | ||
948 | if (IS_ERR(f)) | ||
949 | goto out_error; | ||
950 | fd_install(fd, f); | ||
951 | } | ||
952 | out: | ||
953 | putname(tmp); | ||
954 | } | ||
955 | return fd; | ||
956 | |||
957 | out_error: | ||
958 | put_unused_fd(fd); | ||
959 | fd = error; | ||
960 | goto out; | ||
961 | } | ||
962 | EXPORT_SYMBOL_GPL(sys_open); | ||
963 | |||
964 | #ifndef __alpha__ | ||
965 | |||
966 | /* | ||
967 | * For backward compatibility? Maybe this should be moved | ||
968 | * into arch/i386 instead? | ||
969 | */ | ||
970 | asmlinkage long sys_creat(const char __user * pathname, int mode) | ||
971 | { | ||
972 | return sys_open(pathname, O_CREAT | O_WRONLY | O_TRUNC, mode); | ||
973 | } | ||
974 | |||
975 | #endif | ||
976 | |||
977 | /* | ||
978 | * "id" is the POSIX thread ID. We use the | ||
979 | * files pointer for this.. | ||
980 | */ | ||
981 | int filp_close(struct file *filp, fl_owner_t id) | ||
982 | { | ||
983 | int retval; | ||
984 | |||
985 | /* Report and clear outstanding errors */ | ||
986 | retval = filp->f_error; | ||
987 | if (retval) | ||
988 | filp->f_error = 0; | ||
989 | |||
990 | if (!file_count(filp)) { | ||
991 | printk(KERN_ERR "VFS: Close: file count is 0\n"); | ||
992 | return retval; | ||
993 | } | ||
994 | |||
995 | if (filp->f_op && filp->f_op->flush) { | ||
996 | int err = filp->f_op->flush(filp); | ||
997 | if (!retval) | ||
998 | retval = err; | ||
999 | } | ||
1000 | |||
1001 | dnotify_flush(filp, id); | ||
1002 | locks_remove_posix(filp, id); | ||
1003 | fput(filp); | ||
1004 | return retval; | ||
1005 | } | ||
1006 | |||
1007 | EXPORT_SYMBOL(filp_close); | ||
1008 | |||
1009 | /* | ||
1010 | * Careful here! We test whether the file pointer is NULL before | ||
1011 | * releasing the fd. This ensures that one clone task can't release | ||
1012 | * an fd while another clone is opening it. | ||
1013 | */ | ||
1014 | asmlinkage long sys_close(unsigned int fd) | ||
1015 | { | ||
1016 | struct file * filp; | ||
1017 | struct files_struct *files = current->files; | ||
1018 | |||
1019 | spin_lock(&files->file_lock); | ||
1020 | if (fd >= files->max_fds) | ||
1021 | goto out_unlock; | ||
1022 | filp = files->fd[fd]; | ||
1023 | if (!filp) | ||
1024 | goto out_unlock; | ||
1025 | files->fd[fd] = NULL; | ||
1026 | FD_CLR(fd, files->close_on_exec); | ||
1027 | __put_unused_fd(files, fd); | ||
1028 | spin_unlock(&files->file_lock); | ||
1029 | return filp_close(filp, files); | ||
1030 | |||
1031 | out_unlock: | ||
1032 | spin_unlock(&files->file_lock); | ||
1033 | return -EBADF; | ||
1034 | } | ||
1035 | |||
1036 | EXPORT_SYMBOL(sys_close); | ||
1037 | |||
1038 | /* | ||
1039 | * This routine simulates a hangup on the tty, to arrange that users | ||
1040 | * are given clean terminals at login time. | ||
1041 | */ | ||
1042 | asmlinkage long sys_vhangup(void) | ||
1043 | { | ||
1044 | if (capable(CAP_SYS_TTY_CONFIG)) { | ||
1045 | tty_vhangup(current->signal->tty); | ||
1046 | return 0; | ||
1047 | } | ||
1048 | return -EPERM; | ||
1049 | } | ||
1050 | |||
1051 | /* | ||
1052 | * Called when an inode is about to be open. | ||
1053 | * We use this to disallow opening large files on 32bit systems if | ||
1054 | * the caller didn't specify O_LARGEFILE. On 64bit systems we force | ||
1055 | * on this flag in sys_open. | ||
1056 | */ | ||
1057 | int generic_file_open(struct inode * inode, struct file * filp) | ||
1058 | { | ||
1059 | if (!(filp->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS) | ||
1060 | return -EFBIG; | ||
1061 | return 0; | ||
1062 | } | ||
1063 | |||
1064 | EXPORT_SYMBOL(generic_file_open); | ||
1065 | |||
1066 | /* | ||
1067 | * This is used by subsystems that don't want seekable | ||
1068 | * file descriptors | ||
1069 | */ | ||
1070 | int nonseekable_open(struct inode *inode, struct file *filp) | ||
1071 | { | ||
1072 | filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE); | ||
1073 | return 0; | ||
1074 | } | ||
1075 | |||
1076 | EXPORT_SYMBOL(nonseekable_open); | ||