This source file includes following definitions.
- do_truncate
- vfs_truncate
- do_sys_truncate
- SYSCALL_DEFINE2
- COMPAT_SYSCALL_DEFINE2
- do_sys_ftruncate
- SYSCALL_DEFINE2
- COMPAT_SYSCALL_DEFINE2
- SYSCALL_DEFINE2
- SYSCALL_DEFINE2
- vfs_fallocate
- ksys_fallocate
- SYSCALL_DEFINE4
- do_faccessat
- SYSCALL_DEFINE3
- SYSCALL_DEFINE2
- ksys_chdir
- SYSCALL_DEFINE1
- SYSCALL_DEFINE1
- ksys_chroot
- SYSCALL_DEFINE1
- chmod_common
- ksys_fchmod
- SYSCALL_DEFINE2
- do_fchmodat
- SYSCALL_DEFINE3
- SYSCALL_DEFINE2
- chown_common
- do_fchownat
- SYSCALL_DEFINE5
- SYSCALL_DEFINE3
- SYSCALL_DEFINE3
- ksys_fchown
- SYSCALL_DEFINE3
- do_dentry_open
- finish_open
- finish_no_open
- file_path
- vfs_open
- dentry_open
- open_with_fake_path
- build_open_flags
- file_open_name
- filp_open
- file_open_root
- do_sys_open
- SYSCALL_DEFINE3
- SYSCALL_DEFINE4
- COMPAT_SYSCALL_DEFINE3
- COMPAT_SYSCALL_DEFINE4
- SYSCALL_DEFINE2
- filp_close
- SYSCALL_DEFINE1
- SYSCALL_DEFINE0
- generic_file_open
- nonseekable_open
- stream_open
1
2
3
4
5
6
7
8 #include <linux/string.h>
9 #include <linux/mm.h>
10 #include <linux/file.h>
11 #include <linux/fdtable.h>
12 #include <linux/fsnotify.h>
13 #include <linux/module.h>
14 #include <linux/tty.h>
15 #include <linux/namei.h>
16 #include <linux/backing-dev.h>
17 #include <linux/capability.h>
18 #include <linux/securebits.h>
19 #include <linux/security.h>
20 #include <linux/mount.h>
21 #include <linux/fcntl.h>
22 #include <linux/slab.h>
23 #include <linux/uaccess.h>
24 #include <linux/fs.h>
25 #include <linux/personality.h>
26 #include <linux/pagemap.h>
27 #include <linux/syscalls.h>
28 #include <linux/rcupdate.h>
29 #include <linux/audit.h>
30 #include <linux/falloc.h>
31 #include <linux/fs_struct.h>
32 #include <linux/ima.h>
33 #include <linux/dnotify.h>
34 #include <linux/compat.h>
35
36 #include "internal.h"
37
38 int do_truncate(struct dentry *dentry, loff_t length, unsigned int time_attrs,
39 struct file *filp)
40 {
41 int ret;
42 struct iattr newattrs;
43
44
45 if (length < 0)
46 return -EINVAL;
47
48 newattrs.ia_size = length;
49 newattrs.ia_valid = ATTR_SIZE | time_attrs;
50 if (filp) {
51 newattrs.ia_file = filp;
52 newattrs.ia_valid |= ATTR_FILE;
53 }
54
55
56 ret = dentry_needs_remove_privs(dentry);
57 if (ret < 0)
58 return ret;
59 if (ret)
60 newattrs.ia_valid |= ret | ATTR_FORCE;
61
62 inode_lock(dentry->d_inode);
63
64 ret = notify_change(dentry, &newattrs, NULL);
65 inode_unlock(dentry->d_inode);
66 return ret;
67 }
68
69 long vfs_truncate(const struct path *path, loff_t length)
70 {
71 struct inode *inode;
72 long error;
73
74 inode = path->dentry->d_inode;
75
76
77 if (S_ISDIR(inode->i_mode))
78 return -EISDIR;
79 if (!S_ISREG(inode->i_mode))
80 return -EINVAL;
81
82 error = mnt_want_write(path->mnt);
83 if (error)
84 goto out;
85
86 error = inode_permission(inode, MAY_WRITE);
87 if (error)
88 goto mnt_drop_write_and_out;
89
90 error = -EPERM;
91 if (IS_APPEND(inode))
92 goto mnt_drop_write_and_out;
93
94 error = get_write_access(inode);
95 if (error)
96 goto mnt_drop_write_and_out;
97
98
99
100
101
102 error = break_lease(inode, O_WRONLY);
103 if (error)
104 goto put_write_and_out;
105
106 error = locks_verify_truncate(inode, NULL, length);
107 if (!error)
108 error = security_path_truncate(path);
109 if (!error)
110 error = do_truncate(path->dentry, length, 0, NULL);
111
112 put_write_and_out:
113 put_write_access(inode);
114 mnt_drop_write_and_out:
115 mnt_drop_write(path->mnt);
116 out:
117 return error;
118 }
119 EXPORT_SYMBOL_GPL(vfs_truncate);
120
121 long do_sys_truncate(const char __user *pathname, loff_t length)
122 {
123 unsigned int lookup_flags = LOOKUP_FOLLOW;
124 struct path path;
125 int error;
126
127 if (length < 0)
128 return -EINVAL;
129
130 retry:
131 error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path);
132 if (!error) {
133 error = vfs_truncate(&path, length);
134 path_put(&path);
135 }
136 if (retry_estale(error, lookup_flags)) {
137 lookup_flags |= LOOKUP_REVAL;
138 goto retry;
139 }
140 return error;
141 }
142
143 SYSCALL_DEFINE2(truncate, const char __user *, path, long, length)
144 {
145 return do_sys_truncate(path, length);
146 }
147
148 #ifdef CONFIG_COMPAT
149 COMPAT_SYSCALL_DEFINE2(truncate, const char __user *, path, compat_off_t, length)
150 {
151 return do_sys_truncate(path, length);
152 }
153 #endif
154
155 long do_sys_ftruncate(unsigned int fd, loff_t length, int small)
156 {
157 struct inode *inode;
158 struct dentry *dentry;
159 struct fd f;
160 int error;
161
162 error = -EINVAL;
163 if (length < 0)
164 goto out;
165 error = -EBADF;
166 f = fdget(fd);
167 if (!f.file)
168 goto out;
169
170
171 if (f.file->f_flags & O_LARGEFILE)
172 small = 0;
173
174 dentry = f.file->f_path.dentry;
175 inode = dentry->d_inode;
176 error = -EINVAL;
177 if (!S_ISREG(inode->i_mode) || !(f.file->f_mode & FMODE_WRITE))
178 goto out_putf;
179
180 error = -EINVAL;
181
182 if (small && length > MAX_NON_LFS)
183 goto out_putf;
184
185 error = -EPERM;
186
187 if (IS_APPEND(file_inode(f.file)))
188 goto out_putf;
189
190 sb_start_write(inode->i_sb);
191 error = locks_verify_truncate(inode, f.file, length);
192 if (!error)
193 error = security_path_truncate(&f.file->f_path);
194 if (!error)
195 error = do_truncate(dentry, length, ATTR_MTIME|ATTR_CTIME, f.file);
196 sb_end_write(inode->i_sb);
197 out_putf:
198 fdput(f);
199 out:
200 return error;
201 }
202
203 SYSCALL_DEFINE2(ftruncate, unsigned int, fd, unsigned long, length)
204 {
205 return do_sys_ftruncate(fd, length, 1);
206 }
207
208 #ifdef CONFIG_COMPAT
209 COMPAT_SYSCALL_DEFINE2(ftruncate, unsigned int, fd, compat_ulong_t, length)
210 {
211 return do_sys_ftruncate(fd, length, 1);
212 }
213 #endif
214
215
216 #if BITS_PER_LONG == 32
217 SYSCALL_DEFINE2(truncate64, const char __user *, path, loff_t, length)
218 {
219 return do_sys_truncate(path, length);
220 }
221
222 SYSCALL_DEFINE2(ftruncate64, unsigned int, fd, loff_t, length)
223 {
224 return do_sys_ftruncate(fd, length, 0);
225 }
226 #endif
227
228
229 int vfs_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
230 {
231 struct inode *inode = file_inode(file);
232 long ret;
233
234 if (offset < 0 || len <= 0)
235 return -EINVAL;
236
237
238 if (mode & ~FALLOC_FL_SUPPORTED_MASK)
239 return -EOPNOTSUPP;
240
241
242 if ((mode & (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_ZERO_RANGE)) ==
243 (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_ZERO_RANGE))
244 return -EOPNOTSUPP;
245
246
247 if ((mode & FALLOC_FL_PUNCH_HOLE) &&
248 !(mode & FALLOC_FL_KEEP_SIZE))
249 return -EOPNOTSUPP;
250
251
252 if ((mode & FALLOC_FL_COLLAPSE_RANGE) &&
253 (mode & ~FALLOC_FL_COLLAPSE_RANGE))
254 return -EINVAL;
255
256
257 if ((mode & FALLOC_FL_INSERT_RANGE) &&
258 (mode & ~FALLOC_FL_INSERT_RANGE))
259 return -EINVAL;
260
261
262 if ((mode & FALLOC_FL_UNSHARE_RANGE) &&
263 (mode & ~(FALLOC_FL_UNSHARE_RANGE | FALLOC_FL_KEEP_SIZE)))
264 return -EINVAL;
265
266 if (!(file->f_mode & FMODE_WRITE))
267 return -EBADF;
268
269
270
271
272 if ((mode & ~FALLOC_FL_KEEP_SIZE) && IS_APPEND(inode))
273 return -EPERM;
274
275 if (IS_IMMUTABLE(inode))
276 return -EPERM;
277
278
279
280
281 if (IS_SWAPFILE(inode))
282 return -ETXTBSY;
283
284
285
286
287
288 ret = security_file_permission(file, MAY_WRITE);
289 if (ret)
290 return ret;
291
292 if (S_ISFIFO(inode->i_mode))
293 return -ESPIPE;
294
295 if (S_ISDIR(inode->i_mode))
296 return -EISDIR;
297
298 if (!S_ISREG(inode->i_mode) && !S_ISBLK(inode->i_mode))
299 return -ENODEV;
300
301
302 if (((offset + len) > inode->i_sb->s_maxbytes) || ((offset + len) < 0))
303 return -EFBIG;
304
305 if (!file->f_op->fallocate)
306 return -EOPNOTSUPP;
307
308 file_start_write(file);
309 ret = file->f_op->fallocate(file, mode, offset, len);
310
311
312
313
314
315
316
317
318 if (ret == 0)
319 fsnotify_modify(file);
320
321 file_end_write(file);
322 return ret;
323 }
324 EXPORT_SYMBOL_GPL(vfs_fallocate);
325
326 int ksys_fallocate(int fd, int mode, loff_t offset, loff_t len)
327 {
328 struct fd f = fdget(fd);
329 int error = -EBADF;
330
331 if (f.file) {
332 error = vfs_fallocate(f.file, mode, offset, len);
333 fdput(f);
334 }
335 return error;
336 }
337
338 SYSCALL_DEFINE4(fallocate, int, fd, int, mode, loff_t, offset, loff_t, len)
339 {
340 return ksys_fallocate(fd, mode, offset, len);
341 }
342
343
344
345
346
347
348 long do_faccessat(int dfd, const char __user *filename, int mode)
349 {
350 const struct cred *old_cred;
351 struct cred *override_cred;
352 struct path path;
353 struct inode *inode;
354 int res;
355 unsigned int lookup_flags = LOOKUP_FOLLOW;
356
357 if (mode & ~S_IRWXO)
358 return -EINVAL;
359
360 override_cred = prepare_creds();
361 if (!override_cred)
362 return -ENOMEM;
363
364 override_cred->fsuid = override_cred->uid;
365 override_cred->fsgid = override_cred->gid;
366
367 if (!issecure(SECURE_NO_SETUID_FIXUP)) {
368
369 kuid_t root_uid = make_kuid(override_cred->user_ns, 0);
370 if (!uid_eq(override_cred->uid, root_uid))
371 cap_clear(override_cred->cap_effective);
372 else
373 override_cred->cap_effective =
374 override_cred->cap_permitted;
375 }
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394 override_cred->non_rcu = 1;
395
396 old_cred = override_creds(override_cred);
397 retry:
398 res = user_path_at(dfd, filename, lookup_flags, &path);
399 if (res)
400 goto out;
401
402 inode = d_backing_inode(path.dentry);
403
404 if ((mode & MAY_EXEC) && S_ISREG(inode->i_mode)) {
405
406
407
408
409 res = -EACCES;
410 if (path_noexec(&path))
411 goto out_path_release;
412 }
413
414 res = inode_permission(inode, mode | MAY_ACCESS);
415
416 if (res || !(mode & S_IWOTH) || special_file(inode->i_mode))
417 goto out_path_release;
418
419
420
421
422
423
424
425
426
427
428 if (__mnt_is_readonly(path.mnt))
429 res = -EROFS;
430
431 out_path_release:
432 path_put(&path);
433 if (retry_estale(res, lookup_flags)) {
434 lookup_flags |= LOOKUP_REVAL;
435 goto retry;
436 }
437 out:
438 revert_creds(old_cred);
439 put_cred(override_cred);
440 return res;
441 }
442
443 SYSCALL_DEFINE3(faccessat, int, dfd, const char __user *, filename, int, mode)
444 {
445 return do_faccessat(dfd, filename, mode);
446 }
447
448 SYSCALL_DEFINE2(access, const char __user *, filename, int, mode)
449 {
450 return do_faccessat(AT_FDCWD, filename, mode);
451 }
452
453 int ksys_chdir(const char __user *filename)
454 {
455 struct path path;
456 int error;
457 unsigned int lookup_flags = LOOKUP_FOLLOW | LOOKUP_DIRECTORY;
458 retry:
459 error = user_path_at(AT_FDCWD, filename, lookup_flags, &path);
460 if (error)
461 goto out;
462
463 error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_CHDIR);
464 if (error)
465 goto dput_and_out;
466
467 set_fs_pwd(current->fs, &path);
468
469 dput_and_out:
470 path_put(&path);
471 if (retry_estale(error, lookup_flags)) {
472 lookup_flags |= LOOKUP_REVAL;
473 goto retry;
474 }
475 out:
476 return error;
477 }
478
479 SYSCALL_DEFINE1(chdir, const char __user *, filename)
480 {
481 return ksys_chdir(filename);
482 }
483
484 SYSCALL_DEFINE1(fchdir, unsigned int, fd)
485 {
486 struct fd f = fdget_raw(fd);
487 int error;
488
489 error = -EBADF;
490 if (!f.file)
491 goto out;
492
493 error = -ENOTDIR;
494 if (!d_can_lookup(f.file->f_path.dentry))
495 goto out_putf;
496
497 error = inode_permission(file_inode(f.file), MAY_EXEC | MAY_CHDIR);
498 if (!error)
499 set_fs_pwd(current->fs, &f.file->f_path);
500 out_putf:
501 fdput(f);
502 out:
503 return error;
504 }
505
506 int ksys_chroot(const char __user *filename)
507 {
508 struct path path;
509 int error;
510 unsigned int lookup_flags = LOOKUP_FOLLOW | LOOKUP_DIRECTORY;
511 retry:
512 error = user_path_at(AT_FDCWD, filename, lookup_flags, &path);
513 if (error)
514 goto out;
515
516 error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_CHDIR);
517 if (error)
518 goto dput_and_out;
519
520 error = -EPERM;
521 if (!ns_capable(current_user_ns(), CAP_SYS_CHROOT))
522 goto dput_and_out;
523 error = security_path_chroot(&path);
524 if (error)
525 goto dput_and_out;
526
527 set_fs_root(current->fs, &path);
528 error = 0;
529 dput_and_out:
530 path_put(&path);
531 if (retry_estale(error, lookup_flags)) {
532 lookup_flags |= LOOKUP_REVAL;
533 goto retry;
534 }
535 out:
536 return error;
537 }
538
539 SYSCALL_DEFINE1(chroot, const char __user *, filename)
540 {
541 return ksys_chroot(filename);
542 }
543
544 static int chmod_common(const struct path *path, umode_t mode)
545 {
546 struct inode *inode = path->dentry->d_inode;
547 struct inode *delegated_inode = NULL;
548 struct iattr newattrs;
549 int error;
550
551 error = mnt_want_write(path->mnt);
552 if (error)
553 return error;
554 retry_deleg:
555 inode_lock(inode);
556 error = security_path_chmod(path, mode);
557 if (error)
558 goto out_unlock;
559 newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO);
560 newattrs.ia_valid = ATTR_MODE | ATTR_CTIME;
561 error = notify_change(path->dentry, &newattrs, &delegated_inode);
562 out_unlock:
563 inode_unlock(inode);
564 if (delegated_inode) {
565 error = break_deleg_wait(&delegated_inode);
566 if (!error)
567 goto retry_deleg;
568 }
569 mnt_drop_write(path->mnt);
570 return error;
571 }
572
573 int ksys_fchmod(unsigned int fd, umode_t mode)
574 {
575 struct fd f = fdget(fd);
576 int err = -EBADF;
577
578 if (f.file) {
579 audit_file(f.file);
580 err = chmod_common(&f.file->f_path, mode);
581 fdput(f);
582 }
583 return err;
584 }
585
586 SYSCALL_DEFINE2(fchmod, unsigned int, fd, umode_t, mode)
587 {
588 return ksys_fchmod(fd, mode);
589 }
590
591 int do_fchmodat(int dfd, const char __user *filename, umode_t mode)
592 {
593 struct path path;
594 int error;
595 unsigned int lookup_flags = LOOKUP_FOLLOW;
596 retry:
597 error = user_path_at(dfd, filename, lookup_flags, &path);
598 if (!error) {
599 error = chmod_common(&path, mode);
600 path_put(&path);
601 if (retry_estale(error, lookup_flags)) {
602 lookup_flags |= LOOKUP_REVAL;
603 goto retry;
604 }
605 }
606 return error;
607 }
608
609 SYSCALL_DEFINE3(fchmodat, int, dfd, const char __user *, filename,
610 umode_t, mode)
611 {
612 return do_fchmodat(dfd, filename, mode);
613 }
614
615 SYSCALL_DEFINE2(chmod, const char __user *, filename, umode_t, mode)
616 {
617 return do_fchmodat(AT_FDCWD, filename, mode);
618 }
619
620 static int chown_common(const struct path *path, uid_t user, gid_t group)
621 {
622 struct inode *inode = path->dentry->d_inode;
623 struct inode *delegated_inode = NULL;
624 int error;
625 struct iattr newattrs;
626 kuid_t uid;
627 kgid_t gid;
628
629 uid = make_kuid(current_user_ns(), user);
630 gid = make_kgid(current_user_ns(), group);
631
632 retry_deleg:
633 newattrs.ia_valid = ATTR_CTIME;
634 if (user != (uid_t) -1) {
635 if (!uid_valid(uid))
636 return -EINVAL;
637 newattrs.ia_valid |= ATTR_UID;
638 newattrs.ia_uid = uid;
639 }
640 if (group != (gid_t) -1) {
641 if (!gid_valid(gid))
642 return -EINVAL;
643 newattrs.ia_valid |= ATTR_GID;
644 newattrs.ia_gid = gid;
645 }
646 if (!S_ISDIR(inode->i_mode))
647 newattrs.ia_valid |=
648 ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV;
649 inode_lock(inode);
650 error = security_path_chown(path, uid, gid);
651 if (!error)
652 error = notify_change(path->dentry, &newattrs, &delegated_inode);
653 inode_unlock(inode);
654 if (delegated_inode) {
655 error = break_deleg_wait(&delegated_inode);
656 if (!error)
657 goto retry_deleg;
658 }
659 return error;
660 }
661
662 int do_fchownat(int dfd, const char __user *filename, uid_t user, gid_t group,
663 int flag)
664 {
665 struct path path;
666 int error = -EINVAL;
667 int lookup_flags;
668
669 if ((flag & ~(AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH)) != 0)
670 goto out;
671
672 lookup_flags = (flag & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW;
673 if (flag & AT_EMPTY_PATH)
674 lookup_flags |= LOOKUP_EMPTY;
675 retry:
676 error = user_path_at(dfd, filename, lookup_flags, &path);
677 if (error)
678 goto out;
679 error = mnt_want_write(path.mnt);
680 if (error)
681 goto out_release;
682 error = chown_common(&path, user, group);
683 mnt_drop_write(path.mnt);
684 out_release:
685 path_put(&path);
686 if (retry_estale(error, lookup_flags)) {
687 lookup_flags |= LOOKUP_REVAL;
688 goto retry;
689 }
690 out:
691 return error;
692 }
693
694 SYSCALL_DEFINE5(fchownat, int, dfd, const char __user *, filename, uid_t, user,
695 gid_t, group, int, flag)
696 {
697 return do_fchownat(dfd, filename, user, group, flag);
698 }
699
700 SYSCALL_DEFINE3(chown, const char __user *, filename, uid_t, user, gid_t, group)
701 {
702 return do_fchownat(AT_FDCWD, filename, user, group, 0);
703 }
704
705 SYSCALL_DEFINE3(lchown, const char __user *, filename, uid_t, user, gid_t, group)
706 {
707 return do_fchownat(AT_FDCWD, filename, user, group,
708 AT_SYMLINK_NOFOLLOW);
709 }
710
711 int ksys_fchown(unsigned int fd, uid_t user, gid_t group)
712 {
713 struct fd f = fdget(fd);
714 int error = -EBADF;
715
716 if (!f.file)
717 goto out;
718
719 error = mnt_want_write_file(f.file);
720 if (error)
721 goto out_fput;
722 audit_file(f.file);
723 error = chown_common(&f.file->f_path, user, group);
724 mnt_drop_write_file(f.file);
725 out_fput:
726 fdput(f);
727 out:
728 return error;
729 }
730
731 SYSCALL_DEFINE3(fchown, unsigned int, fd, uid_t, user, gid_t, group)
732 {
733 return ksys_fchown(fd, user, group);
734 }
735
736 static int do_dentry_open(struct file *f,
737 struct inode *inode,
738 int (*open)(struct inode *, struct file *))
739 {
740 static const struct file_operations empty_fops = {};
741 int error;
742
743 path_get(&f->f_path);
744 f->f_inode = inode;
745 f->f_mapping = inode->i_mapping;
746
747
748 f->f_wb_err = filemap_sample_wb_err(f->f_mapping);
749
750 if (unlikely(f->f_flags & O_PATH)) {
751 f->f_mode = FMODE_PATH | FMODE_OPENED;
752 f->f_op = &empty_fops;
753 return 0;
754 }
755
756
757 if (unlikely(f->f_flags & FMODE_EXEC && !S_ISREG(inode->i_mode))) {
758 error = -EACCES;
759 goto cleanup_file;
760 }
761
762 if (f->f_mode & FMODE_WRITE && !special_file(inode->i_mode)) {
763 error = get_write_access(inode);
764 if (unlikely(error))
765 goto cleanup_file;
766 error = __mnt_want_write(f->f_path.mnt);
767 if (unlikely(error)) {
768 put_write_access(inode);
769 goto cleanup_file;
770 }
771 f->f_mode |= FMODE_WRITER;
772 }
773
774
775 if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode))
776 f->f_mode |= FMODE_ATOMIC_POS;
777
778 f->f_op = fops_get(inode->i_fop);
779 if (WARN_ON(!f->f_op)) {
780 error = -ENODEV;
781 goto cleanup_all;
782 }
783
784 error = security_file_open(f);
785 if (error)
786 goto cleanup_all;
787
788 error = break_lease(locks_inode(f), f->f_flags);
789 if (error)
790 goto cleanup_all;
791
792
793 f->f_mode |= FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE;
794 if (!open)
795 open = f->f_op->open;
796 if (open) {
797 error = open(inode, f);
798 if (error)
799 goto cleanup_all;
800 }
801 f->f_mode |= FMODE_OPENED;
802 if ((f->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ)
803 i_readcount_inc(inode);
804 if ((f->f_mode & FMODE_READ) &&
805 likely(f->f_op->read || f->f_op->read_iter))
806 f->f_mode |= FMODE_CAN_READ;
807 if ((f->f_mode & FMODE_WRITE) &&
808 likely(f->f_op->write || f->f_op->write_iter))
809 f->f_mode |= FMODE_CAN_WRITE;
810
811 f->f_write_hint = WRITE_LIFE_NOT_SET;
812 f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);
813
814 file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping);
815
816
817 if (f->f_flags & O_DIRECT) {
818 if (!f->f_mapping->a_ops || !f->f_mapping->a_ops->direct_IO)
819 return -EINVAL;
820 }
821
822
823
824
825
826 if ((f->f_mode & FMODE_WRITE) && filemap_nr_thps(inode->i_mapping))
827 truncate_pagecache(inode, 0);
828
829 return 0;
830
831 cleanup_all:
832 if (WARN_ON_ONCE(error > 0))
833 error = -EINVAL;
834 fops_put(f->f_op);
835 if (f->f_mode & FMODE_WRITER) {
836 put_write_access(inode);
837 __mnt_drop_write(f->f_path.mnt);
838 }
839 cleanup_file:
840 path_put(&f->f_path);
841 f->f_path.mnt = NULL;
842 f->f_path.dentry = NULL;
843 f->f_inode = NULL;
844 return error;
845 }
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865 int finish_open(struct file *file, struct dentry *dentry,
866 int (*open)(struct inode *, struct file *))
867 {
868 BUG_ON(file->f_mode & FMODE_OPENED);
869
870 file->f_path.dentry = dentry;
871 return do_dentry_open(file, d_backing_inode(dentry), open);
872 }
873 EXPORT_SYMBOL(finish_open);
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889 int finish_no_open(struct file *file, struct dentry *dentry)
890 {
891 file->f_path.dentry = dentry;
892 return 0;
893 }
894 EXPORT_SYMBOL(finish_no_open);
895
896 char *file_path(struct file *filp, char *buf, int buflen)
897 {
898 return d_path(&filp->f_path, buf, buflen);
899 }
900 EXPORT_SYMBOL(file_path);
901
902
903
904
905
906
907
908 int vfs_open(const struct path *path, struct file *file)
909 {
910 file->f_path = *path;
911 return do_dentry_open(file, d_backing_inode(path->dentry), NULL);
912 }
913
914 struct file *dentry_open(const struct path *path, int flags,
915 const struct cred *cred)
916 {
917 int error;
918 struct file *f;
919
920 validate_creds(cred);
921
922
923 BUG_ON(!path->mnt);
924
925 f = alloc_empty_file(flags, cred);
926 if (!IS_ERR(f)) {
927 error = vfs_open(path, f);
928 if (error) {
929 fput(f);
930 f = ERR_PTR(error);
931 }
932 }
933 return f;
934 }
935 EXPORT_SYMBOL(dentry_open);
936
937 struct file *open_with_fake_path(const struct path *path, int flags,
938 struct inode *inode, const struct cred *cred)
939 {
940 struct file *f = alloc_empty_file_noaccount(flags, cred);
941 if (!IS_ERR(f)) {
942 int error;
943
944 f->f_path = *path;
945 error = do_dentry_open(f, inode, NULL);
946 if (error) {
947 fput(f);
948 f = ERR_PTR(error);
949 }
950 }
951 return f;
952 }
953 EXPORT_SYMBOL(open_with_fake_path);
954
955 static inline int build_open_flags(int flags, umode_t mode, struct open_flags *op)
956 {
957 int lookup_flags = 0;
958 int acc_mode = ACC_MODE(flags);
959
960
961
962
963
964 flags &= VALID_OPEN_FLAGS;
965
966 if (flags & (O_CREAT | __O_TMPFILE))
967 op->mode = (mode & S_IALLUGO) | S_IFREG;
968 else
969 op->mode = 0;
970
971
972 flags &= ~FMODE_NONOTIFY & ~O_CLOEXEC;
973
974
975
976
977
978
979
980 if (flags & __O_SYNC)
981 flags |= O_DSYNC;
982
983 if (flags & __O_TMPFILE) {
984 if ((flags & O_TMPFILE_MASK) != O_TMPFILE)
985 return -EINVAL;
986 if (!(acc_mode & MAY_WRITE))
987 return -EINVAL;
988 } else if (flags & O_PATH) {
989
990
991
992
993 flags &= O_DIRECTORY | O_NOFOLLOW | O_PATH;
994 acc_mode = 0;
995 }
996
997 op->open_flag = flags;
998
999
1000 if (flags & O_TRUNC)
1001 acc_mode |= MAY_WRITE;
1002
1003
1004
1005 if (flags & O_APPEND)
1006 acc_mode |= MAY_APPEND;
1007
1008 op->acc_mode = acc_mode;
1009
1010 op->intent = flags & O_PATH ? 0 : LOOKUP_OPEN;
1011
1012 if (flags & O_CREAT) {
1013 op->intent |= LOOKUP_CREATE;
1014 if (flags & O_EXCL)
1015 op->intent |= LOOKUP_EXCL;
1016 }
1017
1018 if (flags & O_DIRECTORY)
1019 lookup_flags |= LOOKUP_DIRECTORY;
1020 if (!(flags & O_NOFOLLOW))
1021 lookup_flags |= LOOKUP_FOLLOW;
1022 op->lookup_flags = lookup_flags;
1023 return 0;
1024 }
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037 struct file *file_open_name(struct filename *name, int flags, umode_t mode)
1038 {
1039 struct open_flags op;
1040 int err = build_open_flags(flags, mode, &op);
1041 return err ? ERR_PTR(err) : do_filp_open(AT_FDCWD, name, &op);
1042 }
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055 struct file *filp_open(const char *filename, int flags, umode_t mode)
1056 {
1057 struct filename *name = getname_kernel(filename);
1058 struct file *file = ERR_CAST(name);
1059
1060 if (!IS_ERR(name)) {
1061 file = file_open_name(name, flags, mode);
1062 putname(name);
1063 }
1064 return file;
1065 }
1066 EXPORT_SYMBOL(filp_open);
1067
1068 struct file *file_open_root(struct dentry *dentry, struct vfsmount *mnt,
1069 const char *filename, int flags, umode_t mode)
1070 {
1071 struct open_flags op;
1072 int err = build_open_flags(flags, mode, &op);
1073 if (err)
1074 return ERR_PTR(err);
1075 return do_file_open_root(dentry, mnt, filename, &op);
1076 }
1077 EXPORT_SYMBOL(file_open_root);
1078
1079 long do_sys_open(int dfd, const char __user *filename, int flags, umode_t mode)
1080 {
1081 struct open_flags op;
1082 int fd = build_open_flags(flags, mode, &op);
1083 struct filename *tmp;
1084
1085 if (fd)
1086 return fd;
1087
1088 tmp = getname(filename);
1089 if (IS_ERR(tmp))
1090 return PTR_ERR(tmp);
1091
1092 fd = get_unused_fd_flags(flags);
1093 if (fd >= 0) {
1094 struct file *f = do_filp_open(dfd, tmp, &op);
1095 if (IS_ERR(f)) {
1096 put_unused_fd(fd);
1097 fd = PTR_ERR(f);
1098 } else {
1099 fsnotify_open(f);
1100 fd_install(fd, f);
1101 }
1102 }
1103 putname(tmp);
1104 return fd;
1105 }
1106
1107 SYSCALL_DEFINE3(open, const char __user *, filename, int, flags, umode_t, mode)
1108 {
1109 if (force_o_largefile())
1110 flags |= O_LARGEFILE;
1111
1112 return do_sys_open(AT_FDCWD, filename, flags, mode);
1113 }
1114
1115 SYSCALL_DEFINE4(openat, int, dfd, const char __user *, filename, int, flags,
1116 umode_t, mode)
1117 {
1118 if (force_o_largefile())
1119 flags |= O_LARGEFILE;
1120
1121 return do_sys_open(dfd, filename, flags, mode);
1122 }
1123
1124 #ifdef CONFIG_COMPAT
1125
1126
1127
1128
1129 COMPAT_SYSCALL_DEFINE3(open, const char __user *, filename, int, flags, umode_t, mode)
1130 {
1131 return do_sys_open(AT_FDCWD, filename, flags, mode);
1132 }
1133
1134
1135
1136
1137
1138 COMPAT_SYSCALL_DEFINE4(openat, int, dfd, const char __user *, filename, int, flags, umode_t, mode)
1139 {
1140 return do_sys_open(dfd, filename, flags, mode);
1141 }
1142 #endif
1143
1144 #ifndef __alpha__
1145
1146
1147
1148
1149
1150 SYSCALL_DEFINE2(creat, const char __user *, pathname, umode_t, mode)
1151 {
1152 return ksys_open(pathname, O_CREAT | O_WRONLY | O_TRUNC, mode);
1153 }
1154
1155 #endif
1156
1157
1158
1159
1160
1161 int filp_close(struct file *filp, fl_owner_t id)
1162 {
1163 int retval = 0;
1164
1165 if (!file_count(filp)) {
1166 printk(KERN_ERR "VFS: Close: file count is 0\n");
1167 return 0;
1168 }
1169
1170 if (filp->f_op->flush)
1171 retval = filp->f_op->flush(filp, id);
1172
1173 if (likely(!(filp->f_mode & FMODE_PATH))) {
1174 dnotify_flush(filp, id);
1175 locks_remove_posix(filp, id);
1176 }
1177 fput(filp);
1178 return retval;
1179 }
1180
1181 EXPORT_SYMBOL(filp_close);
1182
1183
1184
1185
1186
1187
1188 SYSCALL_DEFINE1(close, unsigned int, fd)
1189 {
1190 int retval = __close_fd(current->files, fd);
1191
1192
1193 if (unlikely(retval == -ERESTARTSYS ||
1194 retval == -ERESTARTNOINTR ||
1195 retval == -ERESTARTNOHAND ||
1196 retval == -ERESTART_RESTARTBLOCK))
1197 retval = -EINTR;
1198
1199 return retval;
1200 }
1201
1202
1203
1204
1205
1206 SYSCALL_DEFINE0(vhangup)
1207 {
1208 if (capable(CAP_SYS_TTY_CONFIG)) {
1209 tty_vhangup_self();
1210 return 0;
1211 }
1212 return -EPERM;
1213 }
1214
1215
1216
1217
1218
1219
1220
1221 int generic_file_open(struct inode * inode, struct file * filp)
1222 {
1223 if (!(filp->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS)
1224 return -EOVERFLOW;
1225 return 0;
1226 }
1227
1228 EXPORT_SYMBOL(generic_file_open);
1229
1230
1231
1232
1233
1234
1235
1236 int nonseekable_open(struct inode *inode, struct file *filp)
1237 {
1238 filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE);
1239 return 0;
1240 }
1241
1242 EXPORT_SYMBOL(nonseekable_open);
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254 int stream_open(struct inode *inode, struct file *filp)
1255 {
1256 filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE | FMODE_ATOMIC_POS);
1257 filp->f_mode |= FMODE_STREAM;
1258 return 0;
1259 }
1260
1261 EXPORT_SYMBOL(stream_open);