4 * Copyright (C) 1991, 1992 Linus Torvalds
8 * Some corrections by tytso.
11 /* [Feb 1997 T. Schoebel-Theuer] Complete rewrite of the pathname
14 /* [Feb-Apr 2000, AV] Rewrite to the new namespace architecture.
17 #include <linux/init.h>
18 #include <linux/module.h>
19 #include <linux/slab.h>
21 #include <linux/namei.h>
22 #include <linux/quotaops.h>
23 #include <linux/pagemap.h>
24 #include <linux/fsnotify.h>
25 #include <linux/smp_lock.h>
26 #include <linux/personality.h>
27 #include <linux/security.h>
28 #include <linux/syscalls.h>
29 #include <linux/mount.h>
30 #include <linux/audit.h>
31 #include <linux/capability.h>
32 #include <linux/file.h>
33 #include <linux/fcntl.h>
34 #include <linux/namei.h>
35 #include <asm/namei.h>
36 #include <asm/uaccess.h>
38 #define ACC_MODE(x) ("\000\004\002\006"[(x)&O_ACCMODE])
40 /* [Feb-1997 T. Schoebel-Theuer]
41 * Fundamental changes in the pathname lookup mechanisms (namei)
42 * were necessary because of omirr. The reason is that omirr needs
43 * to know the _real_ pathname, not the user-supplied one, in case
44 * of symlinks (and also when transname replacements occur).
46 * The new code replaces the old recursive symlink resolution with
47 * an iterative one (in case of non-nested symlink chains). It does
48 * this with calls to <fs>_follow_link().
49 * As a side effect, dir_namei(), _namei() and follow_link() are now
50 * replaced with a single function lookup_dentry() that can handle all
51 * the special cases of the former code.
53 * With the new dcache, the pathname is stored at each inode, at least as
54 * long as the refcount of the inode is positive. As a side effect, the
55 * size of the dcache depends on the inode cache and thus is dynamic.
57 * [29-Apr-1998 C. Scott Ananian] Updated above description of symlink
58 * resolution to correspond with current state of the code.
60 * Note that the symlink resolution is not *completely* iterative.
61 * There is still a significant amount of tail- and mid- recursion in
62 * the algorithm. Also, note that <fs>_readlink() is not used in
63 * lookup_dentry(): lookup_dentry() on the result of <fs>_readlink()
64 * may return different results than <fs>_follow_link(). Many virtual
65 * filesystems (including /proc) exhibit this behavior.
68 /* [24-Feb-97 T. Schoebel-Theuer] Side effects caused by new implementation:
69 * New symlink semantics: when open() is called with flags O_CREAT | O_EXCL
70 * and the name already exists in form of a symlink, try to create the new
71 * name indicated by the symlink. The old code always complained that the
72 * name already exists, due to not following the symlink even if its target
73 * is nonexistent. The new semantics affects also mknod() and link() when
74 * the name is a symlink pointing to a non-existant name.
76 * I don't know which semantics is the right one, since I have no access
77 * to standards. But I found by trial that HP-UX 9.0 has the full "new"
78 * semantics implemented, while SunOS 4.1.1 and Solaris (SunOS 5.4) have the
79 * "old" one. Personally, I think the new semantics is much more logical.
80 * Note that "ln old new" where "new" is a symlink pointing to a non-existing
81 * file does succeed in both HP-UX and SunOs, but not in Solaris
82 * and in the old Linux semantics.
85 /* [16-Dec-97 Kevin Buhr] For security reasons, we change some symlink
86 * semantics. See the comments in "open_namei" and "do_link" below.
88 * [10-Sep-98 Alan Modra] Another symlink change.
91 /* [Feb-Apr 2000 AV] Complete rewrite. Rules for symlinks:
92 * inside the path - always follow.
93 * in the last component in creation/removal/renaming - never follow.
94 * if LOOKUP_FOLLOW passed - follow.
95 * if the pathname has trailing slashes - follow.
96 * otherwise - don't follow.
97 * (applied in that order).
99 * [Jun 2000 AV] Inconsistent behaviour of open() in case if flags==O_CREAT
100 * restored for 2.4. This is the last surviving part of old 4.2BSD bug.
101 * During the 2.4 we need to fix the userland stuff depending on it -
102 * hopefully we will be able to get rid of that wart in 2.5. So far only
103 * XEmacs seems to be relying on it...
106 * [Sep 2001 AV] Single-semaphore locking scheme (kudos to David Holland)
107 * implemented. Let's see if raised priority of ->s_vfs_rename_mutex gives
108 * any extra contention...
111 /* In order to reduce some races, while at the same time doing additional
112 * checking and hopefully speeding things up, we copy filenames to the
113 * kernel data space before using them..
115 * POSIX.1 2.4: an empty pathname is invalid (ENOENT).
116 * PATH_MAX includes the nul terminator --RR.
118 static int do_getname(const char __user
*filename
, char *page
)
121 unsigned long len
= PATH_MAX
;
123 if (!segment_eq(get_fs(), KERNEL_DS
)) {
124 if ((unsigned long) filename
>= TASK_SIZE
)
126 if (TASK_SIZE
- (unsigned long) filename
< PATH_MAX
)
127 len
= TASK_SIZE
- (unsigned long) filename
;
130 retval
= strncpy_from_user(page
, filename
, len
);
134 return -ENAMETOOLONG
;
140 char * getname(const char __user
* filename
)
144 result
= ERR_PTR(-ENOMEM
);
147 int retval
= do_getname(filename
, tmp
);
152 result
= ERR_PTR(retval
);
155 audit_getname(result
);
159 #ifdef CONFIG_AUDITSYSCALL
160 void putname(const char *name
)
162 if (unlikely(!audit_dummy_context()))
167 EXPORT_SYMBOL(putname
);
172 * generic_permission - check for access rights on a Posix-like filesystem
173 * @inode: inode to check access rights for
174 * @mask: right to check for (%MAY_READ, %MAY_WRITE, %MAY_EXEC)
175 * @check_acl: optional callback to check for Posix ACLs
177 * Used to check for read/write/execute permissions on a file.
178 * We use "fsuid" for this, letting us set arbitrary permissions
179 * for filesystem access without changing the "normal" uids which
180 * are used for other things..
182 int generic_permission(struct inode
*inode
, int mask
,
183 int (*check_acl
)(struct inode
*inode
, int mask
))
185 umode_t mode
= inode
->i_mode
;
187 if (current
->fsuid
== inode
->i_uid
)
190 if (IS_POSIXACL(inode
) && (mode
& S_IRWXG
) && check_acl
) {
191 int error
= check_acl(inode
, mask
);
192 if (error
== -EACCES
)
193 goto check_capabilities
;
194 else if (error
!= -EAGAIN
)
198 if (in_group_p(inode
->i_gid
))
203 * If the DACs are ok we don't need any capability check.
205 if (((mode
& mask
& (MAY_READ
|MAY_WRITE
|MAY_EXEC
)) == mask
))
210 * Read/write DACs are always overridable.
211 * Executable DACs are overridable if at least one exec bit is set.
213 if (!(mask
& MAY_EXEC
) ||
214 (inode
->i_mode
& S_IXUGO
) || S_ISDIR(inode
->i_mode
))
215 if (capable(CAP_DAC_OVERRIDE
))
219 * Searching includes executable on directories, else just read.
221 if (mask
== MAY_READ
|| (S_ISDIR(inode
->i_mode
) && !(mask
& MAY_WRITE
)))
222 if (capable(CAP_DAC_READ_SEARCH
))
228 int permission(struct inode
*inode
, int mask
, struct nameidata
*nd
)
230 umode_t mode
= inode
->i_mode
;
233 if (mask
& MAY_WRITE
) {
236 * Nobody gets write access to a read-only fs.
238 if (IS_RDONLY(inode
) &&
239 (S_ISREG(mode
) || S_ISDIR(mode
) || S_ISLNK(mode
)))
243 * Nobody gets write access to an immutable file.
245 if (IS_IMMUTABLE(inode
))
251 * MAY_EXEC on regular files requires special handling: We override
252 * filesystem execute permissions if the mode bits aren't set.
254 if ((mask
& MAY_EXEC
) && S_ISREG(mode
) && !(mode
& S_IXUGO
))
257 /* Ordinary permission routines do not understand MAY_APPEND. */
258 submask
= mask
& ~MAY_APPEND
;
259 if (inode
->i_op
&& inode
->i_op
->permission
)
260 retval
= inode
->i_op
->permission(inode
, submask
, nd
);
262 retval
= generic_permission(inode
, submask
, NULL
);
266 return security_inode_permission(inode
, mask
, nd
);
270 * vfs_permission - check for access rights to a given path
271 * @nd: lookup result that describes the path
272 * @mask: right to check for (%MAY_READ, %MAY_WRITE, %MAY_EXEC)
274 * Used to check for read/write/execute permissions on a path.
275 * We use "fsuid" for this, letting us set arbitrary permissions
276 * for filesystem access without changing the "normal" uids which
277 * are used for other things.
279 int vfs_permission(struct nameidata
*nd
, int mask
)
281 return permission(nd
->dentry
->d_inode
, mask
, nd
);
285 * file_permission - check for additional access rights to a given file
286 * @file: file to check access rights for
287 * @mask: right to check for (%MAY_READ, %MAY_WRITE, %MAY_EXEC)
289 * Used to check for read/write/execute permissions on an already opened
293 * Do not use this function in new code. All access checks should
294 * be done using vfs_permission().
296 int file_permission(struct file
*file
, int mask
)
298 return permission(file
->f_dentry
->d_inode
, mask
, NULL
);
302 * get_write_access() gets write permission for a file.
303 * put_write_access() releases this write permission.
304 * This is used for regular files.
305 * We cannot support write (and maybe mmap read-write shared) accesses and
306 * MAP_DENYWRITE mmappings simultaneously. The i_writecount field of an inode
307 * can have the following values:
308 * 0: no writers, no VM_DENYWRITE mappings
309 * < 0: (-i_writecount) vm_area_structs with VM_DENYWRITE set exist
310 * > 0: (i_writecount) users are writing to the file.
312 * Normally we operate on that counter with atomic_{inc,dec} and it's safe
313 * except for the cases where we don't hold i_writecount yet. Then we need to
314 * use {get,deny}_write_access() - these functions check the sign and refuse
315 * to do the change if sign is wrong. Exclusion between them is provided by
316 * the inode->i_lock spinlock.
319 int get_write_access(struct inode
* inode
)
321 spin_lock(&inode
->i_lock
);
322 if (atomic_read(&inode
->i_writecount
) < 0) {
323 spin_unlock(&inode
->i_lock
);
326 atomic_inc(&inode
->i_writecount
);
327 spin_unlock(&inode
->i_lock
);
332 int deny_write_access(struct file
* file
)
334 struct inode
*inode
= file
->f_dentry
->d_inode
;
336 spin_lock(&inode
->i_lock
);
337 if (atomic_read(&inode
->i_writecount
) > 0) {
338 spin_unlock(&inode
->i_lock
);
341 atomic_dec(&inode
->i_writecount
);
342 spin_unlock(&inode
->i_lock
);
347 void path_release(struct nameidata
*nd
)
354 * umount() mustn't call path_release()/mntput() as that would clear
357 void path_release_on_umount(struct nameidata
*nd
)
360 mntput_no_expire(nd
->mnt
);
364 * release_open_intent - free up open intent resources
365 * @nd: pointer to nameidata
367 void release_open_intent(struct nameidata
*nd
)
369 if (nd
->intent
.open
.file
->f_dentry
== NULL
)
370 put_filp(nd
->intent
.open
.file
);
372 fput(nd
->intent
.open
.file
);
375 static inline struct dentry
*
376 do_revalidate(struct dentry
*dentry
, struct nameidata
*nd
)
378 int status
= dentry
->d_op
->d_revalidate(dentry
, nd
);
379 if (unlikely(status
<= 0)) {
381 * The dentry failed validation.
382 * If d_revalidate returned 0 attempt to invalidate
383 * the dentry otherwise d_revalidate is asking us
384 * to return a fail status.
387 if (!d_invalidate(dentry
)) {
393 dentry
= ERR_PTR(status
);
400 * Internal lookup() using the new generic dcache.
403 static struct dentry
* cached_lookup(struct dentry
* parent
, struct qstr
* name
, struct nameidata
*nd
)
405 struct dentry
* dentry
= __d_lookup(parent
, name
);
407 /* lockess __d_lookup may fail due to concurrent d_move()
408 * in some unrelated directory, so try with d_lookup
411 dentry
= d_lookup(parent
, name
);
413 if (dentry
&& dentry
->d_op
&& dentry
->d_op
->d_revalidate
)
414 dentry
= do_revalidate(dentry
, nd
);
420 * Short-cut version of permission(), for calling by
421 * path_walk(), when dcache lock is held. Combines parts
422 * of permission() and generic_permission(), and tests ONLY for
423 * MAY_EXEC permission.
425 * If appropriate, check DAC only. If not appropriate, or
426 * short-cut DAC fails, then call permission() to do more
427 * complete permission check.
429 static int exec_permission_lite(struct inode
*inode
,
430 struct nameidata
*nd
)
432 umode_t mode
= inode
->i_mode
;
434 if (inode
->i_op
&& inode
->i_op
->permission
)
437 if (current
->fsuid
== inode
->i_uid
)
439 else if (in_group_p(inode
->i_gid
))
445 if ((inode
->i_mode
& S_IXUGO
) && capable(CAP_DAC_OVERRIDE
))
448 if (S_ISDIR(inode
->i_mode
) && capable(CAP_DAC_OVERRIDE
))
451 if (S_ISDIR(inode
->i_mode
) && capable(CAP_DAC_READ_SEARCH
))
456 return security_inode_permission(inode
, MAY_EXEC
, nd
);
460 * This is called when everything else fails, and we actually have
461 * to go to the low-level filesystem to find out what we should do..
463 * We get the directory semaphore, and after getting that we also
464 * make sure that nobody added the entry to the dcache in the meantime..
467 static struct dentry
* real_lookup(struct dentry
* parent
, struct qstr
* name
, struct nameidata
*nd
)
469 struct dentry
* result
;
470 struct inode
*dir
= parent
->d_inode
;
472 mutex_lock(&dir
->i_mutex
);
474 * First re-do the cached lookup just in case it was created
475 * while we waited for the directory semaphore..
477 * FIXME! This could use version numbering or similar to
478 * avoid unnecessary cache lookups.
480 * The "dcache_lock" is purely to protect the RCU list walker
481 * from concurrent renames at this point (we mustn't get false
482 * negatives from the RCU list walk here, unlike the optimistic
485 * so doing d_lookup() (with seqlock), instead of lockfree __d_lookup
487 result
= d_lookup(parent
, name
);
489 struct dentry
* dentry
= d_alloc(parent
, name
);
490 result
= ERR_PTR(-ENOMEM
);
492 result
= dir
->i_op
->lookup(dir
, dentry
, nd
);
498 mutex_unlock(&dir
->i_mutex
);
503 * Uhhuh! Nasty case: the cache was re-populated while
504 * we waited on the semaphore. Need to revalidate.
506 mutex_unlock(&dir
->i_mutex
);
507 if (result
->d_op
&& result
->d_op
->d_revalidate
) {
508 result
= do_revalidate(result
, nd
);
510 result
= ERR_PTR(-ENOENT
);
515 static int __emul_lookup_dentry(const char *, struct nameidata
*);
518 static __always_inline
int
519 walk_init_root(const char *name
, struct nameidata
*nd
)
521 read_lock(¤t
->fs
->lock
);
522 if (current
->fs
->altroot
&& !(nd
->flags
& LOOKUP_NOALT
)) {
523 nd
->mnt
= mntget(current
->fs
->altrootmnt
);
524 nd
->dentry
= dget(current
->fs
->altroot
);
525 read_unlock(¤t
->fs
->lock
);
526 if (__emul_lookup_dentry(name
,nd
))
528 read_lock(¤t
->fs
->lock
);
530 nd
->mnt
= mntget(current
->fs
->rootmnt
);
531 nd
->dentry
= dget(current
->fs
->root
);
532 read_unlock(¤t
->fs
->lock
);
536 static __always_inline
int __vfs_follow_link(struct nameidata
*nd
, const char *link
)
545 if (!walk_init_root(link
, nd
))
546 /* weird __emul_prefix() stuff did it */
549 res
= link_path_walk(link
, nd
);
551 if (nd
->depth
|| res
|| nd
->last_type
!=LAST_NORM
)
554 * If it is an iterative symlinks resolution in open_namei() we
555 * have to copy the last component. And all that crap because of
556 * bloody create() on broken symlinks. Furrfu...
559 if (unlikely(!name
)) {
563 strcpy(name
, nd
->last
.name
);
564 nd
->last
.name
= name
;
568 return PTR_ERR(link
);
572 struct vfsmount
*mnt
;
573 struct dentry
*dentry
;
576 static inline void dput_path(struct path
*path
, struct nameidata
*nd
)
579 if (path
->mnt
!= nd
->mnt
)
583 static inline void path_to_nameidata(struct path
*path
, struct nameidata
*nd
)
586 if (nd
->mnt
!= path
->mnt
)
589 nd
->dentry
= path
->dentry
;
592 static __always_inline
int __do_follow_link(struct path
*path
, struct nameidata
*nd
)
596 struct dentry
*dentry
= path
->dentry
;
598 touch_atime(path
->mnt
, dentry
);
599 nd_set_link(nd
, NULL
);
601 if (path
->mnt
!= nd
->mnt
) {
602 path_to_nameidata(path
, nd
);
606 cookie
= dentry
->d_inode
->i_op
->follow_link(dentry
, nd
);
607 error
= PTR_ERR(cookie
);
608 if (!IS_ERR(cookie
)) {
609 char *s
= nd_get_link(nd
);
612 error
= __vfs_follow_link(nd
, s
);
613 if (dentry
->d_inode
->i_op
->put_link
)
614 dentry
->d_inode
->i_op
->put_link(dentry
, nd
, cookie
);
623 * This limits recursive symlink follows to 8, while
624 * limiting consecutive symlinks to 40.
626 * Without that kind of total limit, nasty chains of consecutive
627 * symlinks can cause almost arbitrarily long lookups.
629 static inline int do_follow_link(struct path
*path
, struct nameidata
*nd
)
632 if (current
->link_count
>= MAX_NESTED_LINKS
)
634 if (current
->total_link_count
>= 40)
636 BUG_ON(nd
->depth
>= MAX_NESTED_LINKS
);
638 err
= security_inode_follow_link(path
->dentry
, nd
);
641 current
->link_count
++;
642 current
->total_link_count
++;
644 err
= __do_follow_link(path
, nd
);
645 current
->link_count
--;
654 int follow_up(struct vfsmount
**mnt
, struct dentry
**dentry
)
656 struct vfsmount
*parent
;
657 struct dentry
*mountpoint
;
658 spin_lock(&vfsmount_lock
);
659 parent
=(*mnt
)->mnt_parent
;
660 if (parent
== *mnt
) {
661 spin_unlock(&vfsmount_lock
);
665 mountpoint
=dget((*mnt
)->mnt_mountpoint
);
666 spin_unlock(&vfsmount_lock
);
668 *dentry
= mountpoint
;
674 /* no need for dcache_lock, as serialization is taken care in
677 static int __follow_mount(struct path
*path
)
680 while (d_mountpoint(path
->dentry
)) {
681 struct vfsmount
*mounted
= lookup_mnt(path
->mnt
, path
->dentry
);
688 path
->dentry
= dget(mounted
->mnt_root
);
694 static void follow_mount(struct vfsmount
**mnt
, struct dentry
**dentry
)
696 while (d_mountpoint(*dentry
)) {
697 struct vfsmount
*mounted
= lookup_mnt(*mnt
, *dentry
);
703 *dentry
= dget(mounted
->mnt_root
);
707 /* no need for dcache_lock, as serialization is taken care in
710 int follow_down(struct vfsmount
**mnt
, struct dentry
**dentry
)
712 struct vfsmount
*mounted
;
714 mounted
= lookup_mnt(*mnt
, *dentry
);
719 *dentry
= dget(mounted
->mnt_root
);
725 static __always_inline
void follow_dotdot(struct nameidata
*nd
)
728 struct vfsmount
*parent
;
729 struct dentry
*old
= nd
->dentry
;
731 read_lock(¤t
->fs
->lock
);
732 if (nd
->dentry
== current
->fs
->root
&&
733 nd
->mnt
== current
->fs
->rootmnt
) {
734 read_unlock(¤t
->fs
->lock
);
737 read_unlock(¤t
->fs
->lock
);
738 spin_lock(&dcache_lock
);
739 if (nd
->dentry
!= nd
->mnt
->mnt_root
) {
740 nd
->dentry
= dget(nd
->dentry
->d_parent
);
741 spin_unlock(&dcache_lock
);
745 spin_unlock(&dcache_lock
);
746 spin_lock(&vfsmount_lock
);
747 parent
= nd
->mnt
->mnt_parent
;
748 if (parent
== nd
->mnt
) {
749 spin_unlock(&vfsmount_lock
);
753 nd
->dentry
= dget(nd
->mnt
->mnt_mountpoint
);
754 spin_unlock(&vfsmount_lock
);
759 follow_mount(&nd
->mnt
, &nd
->dentry
);
763 * It's more convoluted than I'd like it to be, but... it's still fairly
764 * small and for now I'd prefer to have fast path as straight as possible.
765 * It _is_ time-critical.
767 static int do_lookup(struct nameidata
*nd
, struct qstr
*name
,
770 struct vfsmount
*mnt
= nd
->mnt
;
771 struct dentry
*dentry
= __d_lookup(nd
->dentry
, name
);
775 if (dentry
->d_op
&& dentry
->d_op
->d_revalidate
)
776 goto need_revalidate
;
779 path
->dentry
= dentry
;
780 __follow_mount(path
);
784 dentry
= real_lookup(nd
->dentry
, name
, nd
);
790 dentry
= do_revalidate(dentry
, nd
);
798 return PTR_ERR(dentry
);
803 * This is the basic name resolution function, turning a pathname into
804 * the final dentry. We expect 'base' to be positive and a directory.
806 * Returns 0 and nd will have valid dentry and mnt on success.
807 * Returns error and drops reference to input namei data on failure.
809 static fastcall
int __link_path_walk(const char * name
, struct nameidata
*nd
)
814 unsigned int lookup_flags
= nd
->flags
;
821 inode
= nd
->dentry
->d_inode
;
823 lookup_flags
= LOOKUP_FOLLOW
| (nd
->flags
& LOOKUP_CONTINUE
);
825 /* At this point we know we have a real path component. */
831 nd
->flags
|= LOOKUP_CONTINUE
;
832 err
= exec_permission_lite(inode
, nd
);
834 err
= vfs_permission(nd
, MAY_EXEC
);
839 c
= *(const unsigned char *)name
;
841 hash
= init_name_hash();
844 hash
= partial_name_hash(c
, hash
);
845 c
= *(const unsigned char *)name
;
846 } while (c
&& (c
!= '/'));
847 this.len
= name
- (const char *) this.name
;
848 this.hash
= end_name_hash(hash
);
850 /* remove trailing slashes? */
853 while (*++name
== '/');
855 goto last_with_slashes
;
858 * "." and ".." are special - ".." especially so because it has
859 * to be able to know about the current root directory and
860 * parent relationships.
862 if (this.name
[0] == '.') switch (this.len
) {
866 if (this.name
[1] != '.')
869 inode
= nd
->dentry
->d_inode
;
875 * See if the low-level filesystem might want
876 * to use its own hash..
878 if (nd
->dentry
->d_op
&& nd
->dentry
->d_op
->d_hash
) {
879 err
= nd
->dentry
->d_op
->d_hash(nd
->dentry
, &this);
883 /* This does the actual lookups.. */
884 err
= do_lookup(nd
, &this, &next
);
889 inode
= next
.dentry
->d_inode
;
896 if (inode
->i_op
->follow_link
) {
897 err
= do_follow_link(&next
, nd
);
901 inode
= nd
->dentry
->d_inode
;
908 path_to_nameidata(&next
, nd
);
910 if (!inode
->i_op
->lookup
)
913 /* here ends the main loop */
916 lookup_flags
|= LOOKUP_FOLLOW
| LOOKUP_DIRECTORY
;
918 /* Clear LOOKUP_CONTINUE iff it was previously unset */
919 nd
->flags
&= lookup_flags
| ~LOOKUP_CONTINUE
;
920 if (lookup_flags
& LOOKUP_PARENT
)
922 if (this.name
[0] == '.') switch (this.len
) {
926 if (this.name
[1] != '.')
929 inode
= nd
->dentry
->d_inode
;
934 if (nd
->dentry
->d_op
&& nd
->dentry
->d_op
->d_hash
) {
935 err
= nd
->dentry
->d_op
->d_hash(nd
->dentry
, &this);
939 err
= do_lookup(nd
, &this, &next
);
942 inode
= next
.dentry
->d_inode
;
943 if ((lookup_flags
& LOOKUP_FOLLOW
)
944 && inode
&& inode
->i_op
&& inode
->i_op
->follow_link
) {
945 err
= do_follow_link(&next
, nd
);
948 inode
= nd
->dentry
->d_inode
;
950 path_to_nameidata(&next
, nd
);
954 if (lookup_flags
& LOOKUP_DIRECTORY
) {
956 if (!inode
->i_op
|| !inode
->i_op
->lookup
)
962 nd
->last_type
= LAST_NORM
;
963 if (this.name
[0] != '.')
966 nd
->last_type
= LAST_DOT
;
967 else if (this.len
== 2 && this.name
[1] == '.')
968 nd
->last_type
= LAST_DOTDOT
;
973 * We bypassed the ordinary revalidation routines.
974 * We may need to check the cached dentry for staleness.
976 if (nd
->dentry
&& nd
->dentry
->d_sb
&&
977 (nd
->dentry
->d_sb
->s_type
->fs_flags
& FS_REVAL_DOT
)) {
979 /* Note: we do not d_invalidate() */
980 if (!nd
->dentry
->d_op
->d_revalidate(nd
->dentry
, nd
))
986 dput_path(&next
, nd
);
995 * Wrapper to retry pathname resolution whenever the underlying
996 * file system returns an ESTALE.
998 * Retry the whole path once, forcing real lookup requests
999 * instead of relying on the dcache.
1001 int fastcall
link_path_walk(const char *name
, struct nameidata
*nd
)
1003 struct nameidata save
= *nd
;
1006 /* make sure the stuff we saved doesn't go away */
1010 result
= __link_path_walk(name
, nd
);
1011 if (result
== -ESTALE
) {
1015 nd
->flags
|= LOOKUP_REVAL
;
1016 result
= __link_path_walk(name
, nd
);
1025 int fastcall
path_walk(const char * name
, struct nameidata
*nd
)
1027 current
->total_link_count
= 0;
1028 return link_path_walk(name
, nd
);
1032 * SMP-safe: Returns 1 and nd will have valid dentry and mnt, if
1033 * everything is done. Returns 0 and drops input nd, if lookup failed;
1035 static int __emul_lookup_dentry(const char *name
, struct nameidata
*nd
)
1037 if (path_walk(name
, nd
))
1038 return 0; /* something went wrong... */
1040 if (!nd
->dentry
->d_inode
|| S_ISDIR(nd
->dentry
->d_inode
->i_mode
)) {
1041 struct dentry
*old_dentry
= nd
->dentry
;
1042 struct vfsmount
*old_mnt
= nd
->mnt
;
1043 struct qstr last
= nd
->last
;
1044 int last_type
= nd
->last_type
;
1046 * NAME was not found in alternate root or it's a directory. Try to find
1047 * it in the normal root:
1049 nd
->last_type
= LAST_ROOT
;
1050 read_lock(¤t
->fs
->lock
);
1051 nd
->mnt
= mntget(current
->fs
->rootmnt
);
1052 nd
->dentry
= dget(current
->fs
->root
);
1053 read_unlock(¤t
->fs
->lock
);
1054 if (path_walk(name
, nd
) == 0) {
1055 if (nd
->dentry
->d_inode
) {
1062 nd
->dentry
= old_dentry
;
1065 nd
->last_type
= last_type
;
1070 void set_fs_altroot(void)
1072 char *emul
= __emul_prefix();
1073 struct nameidata nd
;
1074 struct vfsmount
*mnt
= NULL
, *oldmnt
;
1075 struct dentry
*dentry
= NULL
, *olddentry
;
1080 err
= path_lookup(emul
, LOOKUP_FOLLOW
|LOOKUP_DIRECTORY
|LOOKUP_NOALT
, &nd
);
1086 write_lock(¤t
->fs
->lock
);
1087 oldmnt
= current
->fs
->altrootmnt
;
1088 olddentry
= current
->fs
->altroot
;
1089 current
->fs
->altrootmnt
= mnt
;
1090 current
->fs
->altroot
= dentry
;
1091 write_unlock(¤t
->fs
->lock
);
1098 /* Returns 0 and nd will be valid on success; Retuns error, otherwise. */
1099 static int fastcall
do_path_lookup(int dfd
, const char *name
,
1100 unsigned int flags
, struct nameidata
*nd
)
1106 nd
->last_type
= LAST_ROOT
; /* if there are only slashes... */
1111 read_lock(¤t
->fs
->lock
);
1112 if (current
->fs
->altroot
&& !(nd
->flags
& LOOKUP_NOALT
)) {
1113 nd
->mnt
= mntget(current
->fs
->altrootmnt
);
1114 nd
->dentry
= dget(current
->fs
->altroot
);
1115 read_unlock(¤t
->fs
->lock
);
1116 if (__emul_lookup_dentry(name
,nd
))
1117 goto out
; /* found in altroot */
1118 read_lock(¤t
->fs
->lock
);
1120 nd
->mnt
= mntget(current
->fs
->rootmnt
);
1121 nd
->dentry
= dget(current
->fs
->root
);
1122 read_unlock(¤t
->fs
->lock
);
1123 } else if (dfd
== AT_FDCWD
) {
1124 read_lock(¤t
->fs
->lock
);
1125 nd
->mnt
= mntget(current
->fs
->pwdmnt
);
1126 nd
->dentry
= dget(current
->fs
->pwd
);
1127 read_unlock(¤t
->fs
->lock
);
1129 struct dentry
*dentry
;
1131 file
= fget_light(dfd
, &fput_needed
);
1136 dentry
= file
->f_dentry
;
1139 if (!S_ISDIR(dentry
->d_inode
->i_mode
))
1142 retval
= file_permission(file
, MAY_EXEC
);
1146 nd
->mnt
= mntget(file
->f_vfsmnt
);
1147 nd
->dentry
= dget(dentry
);
1149 fput_light(file
, fput_needed
);
1151 current
->total_link_count
= 0;
1152 retval
= link_path_walk(name
, nd
);
1154 if (likely(retval
== 0)) {
1155 if (unlikely(!audit_dummy_context() && nd
&& nd
->dentry
&&
1156 nd
->dentry
->d_inode
))
1157 audit_inode(name
, nd
->dentry
->d_inode
);
1163 fput_light(file
, fput_needed
);
1167 int fastcall
path_lookup(const char *name
, unsigned int flags
,
1168 struct nameidata
*nd
)
1170 return do_path_lookup(AT_FDCWD
, name
, flags
, nd
);
1173 static int __path_lookup_intent_open(int dfd
, const char *name
,
1174 unsigned int lookup_flags
, struct nameidata
*nd
,
1175 int open_flags
, int create_mode
)
1177 struct file
*filp
= get_empty_filp();
1182 nd
->intent
.open
.file
= filp
;
1183 nd
->intent
.open
.flags
= open_flags
;
1184 nd
->intent
.open
.create_mode
= create_mode
;
1185 err
= do_path_lookup(dfd
, name
, lookup_flags
|LOOKUP_OPEN
, nd
);
1186 if (IS_ERR(nd
->intent
.open
.file
)) {
1188 err
= PTR_ERR(nd
->intent
.open
.file
);
1191 } else if (err
!= 0)
1192 release_open_intent(nd
);
1197 * path_lookup_open - lookup a file path with open intent
1198 * @dfd: the directory to use as base, or AT_FDCWD
1199 * @name: pointer to file name
1200 * @lookup_flags: lookup intent flags
1201 * @nd: pointer to nameidata
1202 * @open_flags: open intent flags
1204 int path_lookup_open(int dfd
, const char *name
, unsigned int lookup_flags
,
1205 struct nameidata
*nd
, int open_flags
)
1207 return __path_lookup_intent_open(dfd
, name
, lookup_flags
, nd
,
1212 * path_lookup_create - lookup a file path with open + create intent
1213 * @dfd: the directory to use as base, or AT_FDCWD
1214 * @name: pointer to file name
1215 * @lookup_flags: lookup intent flags
1216 * @nd: pointer to nameidata
1217 * @open_flags: open intent flags
1218 * @create_mode: create intent flags
1220 static int path_lookup_create(int dfd
, const char *name
,
1221 unsigned int lookup_flags
, struct nameidata
*nd
,
1222 int open_flags
, int create_mode
)
1224 return __path_lookup_intent_open(dfd
, name
, lookup_flags
|LOOKUP_CREATE
,
1225 nd
, open_flags
, create_mode
);
1228 int __user_path_lookup_open(const char __user
*name
, unsigned int lookup_flags
,
1229 struct nameidata
*nd
, int open_flags
)
1231 char *tmp
= getname(name
);
1232 int err
= PTR_ERR(tmp
);
1235 err
= __path_lookup_intent_open(AT_FDCWD
, tmp
, lookup_flags
, nd
, open_flags
, 0);
1242 * Restricted form of lookup. Doesn't follow links, single-component only,
1243 * needs parent already locked. Doesn't follow mounts.
1246 static struct dentry
* __lookup_hash(struct qstr
*name
, struct dentry
* base
, struct nameidata
*nd
)
1248 struct dentry
* dentry
;
1249 struct inode
*inode
;
1252 inode
= base
->d_inode
;
1253 err
= permission(inode
, MAY_EXEC
, nd
);
1254 dentry
= ERR_PTR(err
);
1259 * See if the low-level filesystem might want
1260 * to use its own hash..
1262 if (base
->d_op
&& base
->d_op
->d_hash
) {
1263 err
= base
->d_op
->d_hash(base
, name
);
1264 dentry
= ERR_PTR(err
);
1269 dentry
= cached_lookup(base
, name
, nd
);
1271 struct dentry
*new = d_alloc(base
, name
);
1272 dentry
= ERR_PTR(-ENOMEM
);
1275 dentry
= inode
->i_op
->lookup(inode
, new, nd
);
1285 static struct dentry
*lookup_hash(struct nameidata
*nd
)
1287 return __lookup_hash(&nd
->last
, nd
->dentry
, nd
);
1291 struct dentry
* lookup_one_len(const char * name
, struct dentry
* base
, int len
)
1302 hash
= init_name_hash();
1304 c
= *(const unsigned char *)name
++;
1305 if (c
== '/' || c
== '\0')
1307 hash
= partial_name_hash(c
, hash
);
1309 this.hash
= end_name_hash(hash
);
1311 return __lookup_hash(&this, base
, NULL
);
1313 return ERR_PTR(-EACCES
);
1319 * is used by most simple commands to get the inode of a specified name.
1320 * Open, link etc use their own routines, but this is enough for things
1323 * namei exists in two versions: namei/lnamei. The only difference is
1324 * that namei follows links, while lnamei does not.
1327 int fastcall
__user_walk_fd(int dfd
, const char __user
*name
, unsigned flags
,
1328 struct nameidata
*nd
)
1330 char *tmp
= getname(name
);
1331 int err
= PTR_ERR(tmp
);
1334 err
= do_path_lookup(dfd
, tmp
, flags
, nd
);
1340 int fastcall
__user_walk(const char __user
*name
, unsigned flags
, struct nameidata
*nd
)
1342 return __user_walk_fd(AT_FDCWD
, name
, flags
, nd
);
1346 * It's inline, so penalty for filesystems that don't use sticky bit is
1349 static inline int check_sticky(struct inode
*dir
, struct inode
*inode
)
1351 if (!(dir
->i_mode
& S_ISVTX
))
1353 if (inode
->i_uid
== current
->fsuid
)
1355 if (dir
->i_uid
== current
->fsuid
)
1357 return !capable(CAP_FOWNER
);
1361 * Check whether we can remove a link victim from directory dir, check
1362 * whether the type of victim is right.
1363 * 1. We can't do it if dir is read-only (done in permission())
1364 * 2. We should have write and exec permissions on dir
1365 * 3. We can't remove anything from append-only dir
1366 * 4. We can't do anything with immutable dir (done in permission())
1367 * 5. If the sticky bit on dir is set we should either
1368 * a. be owner of dir, or
1369 * b. be owner of victim, or
1370 * c. have CAP_FOWNER capability
1371 * 6. If the victim is append-only or immutable we can't do antyhing with
1372 * links pointing to it.
1373 * 7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
1374 * 8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
1375 * 9. We can't remove a root or mountpoint.
1376 * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
1377 * nfs_async_unlink().
1379 static int may_delete(struct inode
*dir
,struct dentry
*victim
,int isdir
)
1383 if (!victim
->d_inode
)
1386 BUG_ON(victim
->d_parent
->d_inode
!= dir
);
1387 audit_inode_child(victim
->d_name
.name
, victim
->d_inode
, dir
);
1389 error
= permission(dir
,MAY_WRITE
| MAY_EXEC
, NULL
);
1394 if (check_sticky(dir
, victim
->d_inode
)||IS_APPEND(victim
->d_inode
)||
1395 IS_IMMUTABLE(victim
->d_inode
))
1398 if (!S_ISDIR(victim
->d_inode
->i_mode
))
1400 if (IS_ROOT(victim
))
1402 } else if (S_ISDIR(victim
->d_inode
->i_mode
))
1404 if (IS_DEADDIR(dir
))
1406 if (victim
->d_flags
& DCACHE_NFSFS_RENAMED
)
1411 /* Check whether we can create an object with dentry child in directory
1413 * 1. We can't do it if child already exists (open has special treatment for
1414 * this case, but since we are inlined it's OK)
1415 * 2. We can't do it if dir is read-only (done in permission())
1416 * 3. We should have write and exec permissions on dir
1417 * 4. We can't do it if dir is immutable (done in permission())
1419 static inline int may_create(struct inode
*dir
, struct dentry
*child
,
1420 struct nameidata
*nd
)
1424 if (IS_DEADDIR(dir
))
1426 return permission(dir
,MAY_WRITE
| MAY_EXEC
, nd
);
1430 * O_DIRECTORY translates into forcing a directory lookup.
1432 static inline int lookup_flags(unsigned int f
)
1434 unsigned long retval
= LOOKUP_FOLLOW
;
1437 retval
&= ~LOOKUP_FOLLOW
;
1439 if (f
& O_DIRECTORY
)
1440 retval
|= LOOKUP_DIRECTORY
;
1446 * p1 and p2 should be directories on the same fs.
1448 struct dentry
*lock_rename(struct dentry
*p1
, struct dentry
*p2
)
1453 mutex_lock_nested(&p1
->d_inode
->i_mutex
, I_MUTEX_PARENT
);
1457 mutex_lock(&p1
->d_inode
->i_sb
->s_vfs_rename_mutex
);
1459 for (p
= p1
; p
->d_parent
!= p
; p
= p
->d_parent
) {
1460 if (p
->d_parent
== p2
) {
1461 mutex_lock_nested(&p2
->d_inode
->i_mutex
, I_MUTEX_PARENT
);
1462 mutex_lock_nested(&p1
->d_inode
->i_mutex
, I_MUTEX_CHILD
);
1467 for (p
= p2
; p
->d_parent
!= p
; p
= p
->d_parent
) {
1468 if (p
->d_parent
== p1
) {
1469 mutex_lock_nested(&p1
->d_inode
->i_mutex
, I_MUTEX_PARENT
);
1470 mutex_lock_nested(&p2
->d_inode
->i_mutex
, I_MUTEX_CHILD
);
1475 mutex_lock_nested(&p1
->d_inode
->i_mutex
, I_MUTEX_PARENT
);
1476 mutex_lock_nested(&p2
->d_inode
->i_mutex
, I_MUTEX_CHILD
);
1480 void unlock_rename(struct dentry
*p1
, struct dentry
*p2
)
1482 mutex_unlock(&p1
->d_inode
->i_mutex
);
1484 mutex_unlock(&p2
->d_inode
->i_mutex
);
1485 mutex_unlock(&p1
->d_inode
->i_sb
->s_vfs_rename_mutex
);
1489 int vfs_create(struct inode
*dir
, struct dentry
*dentry
, int mode
,
1490 struct nameidata
*nd
)
1492 int error
= may_create(dir
, dentry
, nd
);
1497 if (!dir
->i_op
|| !dir
->i_op
->create
)
1498 return -EACCES
; /* shouldn't it be ENOSYS? */
1501 error
= security_inode_create(dir
, dentry
, mode
);
1505 error
= dir
->i_op
->create(dir
, dentry
, mode
, nd
);
1507 fsnotify_create(dir
, dentry
);
1511 int may_open(struct nameidata
*nd
, int acc_mode
, int flag
)
1513 struct dentry
*dentry
= nd
->dentry
;
1514 struct inode
*inode
= dentry
->d_inode
;
1520 if (S_ISLNK(inode
->i_mode
))
1523 if (S_ISDIR(inode
->i_mode
) && (flag
& FMODE_WRITE
))
1526 error
= vfs_permission(nd
, acc_mode
);
1531 * FIFO's, sockets and device files are special: they don't
1532 * actually live on the filesystem itself, and as such you
1533 * can write to them even if the filesystem is read-only.
1535 if (S_ISFIFO(inode
->i_mode
) || S_ISSOCK(inode
->i_mode
)) {
1537 } else if (S_ISBLK(inode
->i_mode
) || S_ISCHR(inode
->i_mode
)) {
1538 if (nd
->mnt
->mnt_flags
& MNT_NODEV
)
1542 } else if (IS_RDONLY(inode
) && (flag
& FMODE_WRITE
))
1545 * An append-only file must be opened in append mode for writing.
1547 if (IS_APPEND(inode
)) {
1548 if ((flag
& FMODE_WRITE
) && !(flag
& O_APPEND
))
1554 /* O_NOATIME can only be set by the owner or superuser */
1555 if (flag
& O_NOATIME
)
1556 if (current
->fsuid
!= inode
->i_uid
&& !capable(CAP_FOWNER
))
1560 * Ensure there are no outstanding leases on the file.
1562 error
= break_lease(inode
, flag
);
1566 if (flag
& O_TRUNC
) {
1567 error
= get_write_access(inode
);
1572 * Refuse to truncate files with mandatory locks held on them.
1574 error
= locks_verify_locked(inode
);
1578 error
= do_truncate(dentry
, 0, ATTR_MTIME
|ATTR_CTIME
, NULL
);
1580 put_write_access(inode
);
1584 if (flag
& FMODE_WRITE
)
1593 * namei for open - this is in fact almost the whole open-routine.
1595 * Note that the low bits of "flag" aren't the same as in the open
1596 * system call - they are 00 - no permissions needed
1597 * 01 - read permission needed
1598 * 10 - write permission needed
1599 * 11 - read/write permissions needed
1600 * which is a lot more logical, and also allows the "no perm" needed
1601 * for symlinks (where the permissions are checked later).
1604 int open_namei(int dfd
, const char *pathname
, int flag
,
1605 int mode
, struct nameidata
*nd
)
1607 int acc_mode
, error
;
1612 acc_mode
= ACC_MODE(flag
);
1614 /* O_TRUNC implies we need access checks for write permissions */
1616 acc_mode
|= MAY_WRITE
;
1618 /* Allow the LSM permission hook to distinguish append
1619 access from general write access. */
1620 if (flag
& O_APPEND
)
1621 acc_mode
|= MAY_APPEND
;
1624 * The simplest case - just a plain lookup.
1626 if (!(flag
& O_CREAT
)) {
1627 error
= path_lookup_open(dfd
, pathname
, lookup_flags(flag
),
1635 * Create - we need to know the parent.
1637 error
= path_lookup_create(dfd
,pathname
,LOOKUP_PARENT
,nd
,flag
,mode
);
1642 * We have the parent and last component. First of all, check
1643 * that we are not asked to creat(2) an obvious directory - that
1647 if (nd
->last_type
!= LAST_NORM
|| nd
->last
.name
[nd
->last
.len
])
1651 nd
->flags
&= ~LOOKUP_PARENT
;
1652 mutex_lock(&dir
->d_inode
->i_mutex
);
1653 path
.dentry
= lookup_hash(nd
);
1657 error
= PTR_ERR(path
.dentry
);
1658 if (IS_ERR(path
.dentry
)) {
1659 mutex_unlock(&dir
->d_inode
->i_mutex
);
1663 if (IS_ERR(nd
->intent
.open
.file
)) {
1664 mutex_unlock(&dir
->d_inode
->i_mutex
);
1665 error
= PTR_ERR(nd
->intent
.open
.file
);
1669 /* Negative dentry, just create the file */
1670 if (!path
.dentry
->d_inode
) {
1671 if (!IS_POSIXACL(dir
->d_inode
))
1672 mode
&= ~current
->fs
->umask
;
1673 error
= vfs_create(dir
->d_inode
, path
.dentry
, mode
, nd
);
1674 mutex_unlock(&dir
->d_inode
->i_mutex
);
1676 nd
->dentry
= path
.dentry
;
1679 /* Don't check for write permission, don't truncate */
1686 * It already exists.
1688 mutex_unlock(&dir
->d_inode
->i_mutex
);
1689 audit_inode_update(path
.dentry
->d_inode
);
1695 if (__follow_mount(&path
)) {
1697 if (flag
& O_NOFOLLOW
)
1702 if (!path
.dentry
->d_inode
)
1704 if (path
.dentry
->d_inode
->i_op
&& path
.dentry
->d_inode
->i_op
->follow_link
)
1707 path_to_nameidata(&path
, nd
);
1709 if (path
.dentry
->d_inode
&& S_ISDIR(path
.dentry
->d_inode
->i_mode
))
1712 error
= may_open(nd
, acc_mode
, flag
);
1718 dput_path(&path
, nd
);
1720 if (!IS_ERR(nd
->intent
.open
.file
))
1721 release_open_intent(nd
);
1727 if (flag
& O_NOFOLLOW
)
1730 * This is subtle. Instead of calling do_follow_link() we do the
1731 * thing by hands. The reason is that this way we have zero link_count
1732 * and path_walk() (called from ->follow_link) honoring LOOKUP_PARENT.
1733 * After that we have the parent and last component, i.e.
1734 * we are in the same situation as after the first path_walk().
1735 * Well, almost - if the last component is normal we get its copy
1736 * stored in nd->last.name and we will have to putname() it when we
1737 * are done. Procfs-like symlinks just set LAST_BIND.
1739 nd
->flags
|= LOOKUP_PARENT
;
1740 error
= security_inode_follow_link(path
.dentry
, nd
);
1743 error
= __do_follow_link(&path
, nd
);
1745 /* Does someone understand code flow here? Or it is only
1746 * me so stupid? Anathema to whoever designed this non-sense
1747 * with "intent.open".
1749 release_open_intent(nd
);
1752 nd
->flags
&= ~LOOKUP_PARENT
;
1753 if (nd
->last_type
== LAST_BIND
)
1756 if (nd
->last_type
!= LAST_NORM
)
1758 if (nd
->last
.name
[nd
->last
.len
]) {
1759 __putname(nd
->last
.name
);
1764 __putname(nd
->last
.name
);
1768 mutex_lock(&dir
->d_inode
->i_mutex
);
1769 path
.dentry
= lookup_hash(nd
);
1771 __putname(nd
->last
.name
);
1776 * lookup_create - lookup a dentry, creating it if it doesn't exist
1777 * @nd: nameidata info
1778 * @is_dir: directory flag
1780 * Simple function to lookup and return a dentry and create it
1781 * if it doesn't exist. Is SMP-safe.
1783 * Returns with nd->dentry->d_inode->i_mutex locked.
1785 struct dentry
*lookup_create(struct nameidata
*nd
, int is_dir
)
1787 struct dentry
*dentry
= ERR_PTR(-EEXIST
);
1789 mutex_lock_nested(&nd
->dentry
->d_inode
->i_mutex
, I_MUTEX_PARENT
);
1791 * Yucky last component or no last component at all?
1792 * (foo/., foo/.., /////)
1794 if (nd
->last_type
!= LAST_NORM
)
1796 nd
->flags
&= ~LOOKUP_PARENT
;
1797 nd
->flags
|= LOOKUP_CREATE
;
1798 nd
->intent
.open
.flags
= O_EXCL
;
1801 * Do the final lookup.
1803 dentry
= lookup_hash(nd
);
1808 * Special case - lookup gave negative, but... we had foo/bar/
1809 * From the vfs_mknod() POV we just have a negative dentry -
1810 * all is fine. Let's be bastards - you had / on the end, you've
1811 * been asking for (non-existent) directory. -ENOENT for you.
1813 if (!is_dir
&& nd
->last
.name
[nd
->last
.len
] && !dentry
->d_inode
)
1818 dentry
= ERR_PTR(-ENOENT
);
1822 EXPORT_SYMBOL_GPL(lookup_create
);
1824 int vfs_mknod(struct inode
*dir
, struct dentry
*dentry
, int mode
, dev_t dev
)
1826 int error
= may_create(dir
, dentry
, NULL
);
1831 if ((S_ISCHR(mode
) || S_ISBLK(mode
)) && !capable(CAP_MKNOD
))
1834 if (!dir
->i_op
|| !dir
->i_op
->mknod
)
1837 error
= security_inode_mknod(dir
, dentry
, mode
, dev
);
1842 error
= dir
->i_op
->mknod(dir
, dentry
, mode
, dev
);
1844 fsnotify_create(dir
, dentry
);
1848 asmlinkage
long sys_mknodat(int dfd
, const char __user
*filename
, int mode
,
1853 struct dentry
* dentry
;
1854 struct nameidata nd
;
1858 tmp
= getname(filename
);
1860 return PTR_ERR(tmp
);
1862 error
= do_path_lookup(dfd
, tmp
, LOOKUP_PARENT
, &nd
);
1865 dentry
= lookup_create(&nd
, 0);
1866 error
= PTR_ERR(dentry
);
1868 if (!IS_POSIXACL(nd
.dentry
->d_inode
))
1869 mode
&= ~current
->fs
->umask
;
1870 if (!IS_ERR(dentry
)) {
1871 switch (mode
& S_IFMT
) {
1872 case 0: case S_IFREG
:
1873 error
= vfs_create(nd
.dentry
->d_inode
,dentry
,mode
,&nd
);
1875 case S_IFCHR
: case S_IFBLK
:
1876 error
= vfs_mknod(nd
.dentry
->d_inode
,dentry
,mode
,
1877 new_decode_dev(dev
));
1879 case S_IFIFO
: case S_IFSOCK
:
1880 error
= vfs_mknod(nd
.dentry
->d_inode
,dentry
,mode
,0);
1890 mutex_unlock(&nd
.dentry
->d_inode
->i_mutex
);
1898 asmlinkage
long sys_mknod(const char __user
*filename
, int mode
, unsigned dev
)
1900 return sys_mknodat(AT_FDCWD
, filename
, mode
, dev
);
1903 int vfs_mkdir(struct inode
*dir
, struct dentry
*dentry
, int mode
)
1905 int error
= may_create(dir
, dentry
, NULL
);
1910 if (!dir
->i_op
|| !dir
->i_op
->mkdir
)
1913 mode
&= (S_IRWXUGO
|S_ISVTX
);
1914 error
= security_inode_mkdir(dir
, dentry
, mode
);
1919 error
= dir
->i_op
->mkdir(dir
, dentry
, mode
);
1921 fsnotify_mkdir(dir
, dentry
);
1925 asmlinkage
long sys_mkdirat(int dfd
, const char __user
*pathname
, int mode
)
1930 tmp
= getname(pathname
);
1931 error
= PTR_ERR(tmp
);
1933 struct dentry
*dentry
;
1934 struct nameidata nd
;
1936 error
= do_path_lookup(dfd
, tmp
, LOOKUP_PARENT
, &nd
);
1939 dentry
= lookup_create(&nd
, 1);
1940 error
= PTR_ERR(dentry
);
1941 if (!IS_ERR(dentry
)) {
1942 if (!IS_POSIXACL(nd
.dentry
->d_inode
))
1943 mode
&= ~current
->fs
->umask
;
1944 error
= vfs_mkdir(nd
.dentry
->d_inode
, dentry
, mode
);
1947 mutex_unlock(&nd
.dentry
->d_inode
->i_mutex
);
1956 asmlinkage
long sys_mkdir(const char __user
*pathname
, int mode
)
1958 return sys_mkdirat(AT_FDCWD
, pathname
, mode
);
1962 * We try to drop the dentry early: we should have
1963 * a usage count of 2 if we're the only user of this
1964 * dentry, and if that is true (possibly after pruning
1965 * the dcache), then we drop the dentry now.
1967 * A low-level filesystem can, if it choses, legally
1970 * if (!d_unhashed(dentry))
1973 * if it cannot handle the case of removing a directory
1974 * that is still in use by something else..
1976 void dentry_unhash(struct dentry
*dentry
)
1979 if (atomic_read(&dentry
->d_count
))
1980 shrink_dcache_parent(dentry
);
1981 spin_lock(&dcache_lock
);
1982 spin_lock(&dentry
->d_lock
);
1983 if (atomic_read(&dentry
->d_count
) == 2)
1985 spin_unlock(&dentry
->d_lock
);
1986 spin_unlock(&dcache_lock
);
1989 int vfs_rmdir(struct inode
*dir
, struct dentry
*dentry
)
1991 int error
= may_delete(dir
, dentry
, 1);
1996 if (!dir
->i_op
|| !dir
->i_op
->rmdir
)
2001 mutex_lock(&dentry
->d_inode
->i_mutex
);
2002 dentry_unhash(dentry
);
2003 if (d_mountpoint(dentry
))
2006 error
= security_inode_rmdir(dir
, dentry
);
2008 error
= dir
->i_op
->rmdir(dir
, dentry
);
2010 dentry
->d_inode
->i_flags
|= S_DEAD
;
2013 mutex_unlock(&dentry
->d_inode
->i_mutex
);
2022 static long do_rmdir(int dfd
, const char __user
*pathname
)
2026 struct dentry
*dentry
;
2027 struct nameidata nd
;
2029 name
= getname(pathname
);
2031 return PTR_ERR(name
);
2033 error
= do_path_lookup(dfd
, name
, LOOKUP_PARENT
, &nd
);
2037 switch(nd
.last_type
) {
2048 mutex_lock_nested(&nd
.dentry
->d_inode
->i_mutex
, I_MUTEX_PARENT
);
2049 dentry
= lookup_hash(&nd
);
2050 error
= PTR_ERR(dentry
);
2051 if (!IS_ERR(dentry
)) {
2052 error
= vfs_rmdir(nd
.dentry
->d_inode
, dentry
);
2055 mutex_unlock(&nd
.dentry
->d_inode
->i_mutex
);
2063 asmlinkage
long sys_rmdir(const char __user
*pathname
)
2065 return do_rmdir(AT_FDCWD
, pathname
);
2068 int vfs_unlink(struct inode
*dir
, struct dentry
*dentry
)
2070 int error
= may_delete(dir
, dentry
, 0);
2075 if (!dir
->i_op
|| !dir
->i_op
->unlink
)
2080 mutex_lock(&dentry
->d_inode
->i_mutex
);
2081 if (d_mountpoint(dentry
))
2084 error
= security_inode_unlink(dir
, dentry
);
2086 error
= dir
->i_op
->unlink(dir
, dentry
);
2088 mutex_unlock(&dentry
->d_inode
->i_mutex
);
2090 /* We don't d_delete() NFS sillyrenamed files--they still exist. */
2091 if (!error
&& !(dentry
->d_flags
& DCACHE_NFSFS_RENAMED
)) {
2099 * Make sure that the actual truncation of the file will occur outside its
2100 * directory's i_mutex. Truncate can take a long time if there is a lot of
2101 * writeout happening, and we don't want to prevent access to the directory
2102 * while waiting on the I/O.
2104 static long do_unlinkat(int dfd
, const char __user
*pathname
)
2108 struct dentry
*dentry
;
2109 struct nameidata nd
;
2110 struct inode
*inode
= NULL
;
2112 name
= getname(pathname
);
2114 return PTR_ERR(name
);
2116 error
= do_path_lookup(dfd
, name
, LOOKUP_PARENT
, &nd
);
2120 if (nd
.last_type
!= LAST_NORM
)
2122 mutex_lock_nested(&nd
.dentry
->d_inode
->i_mutex
, I_MUTEX_PARENT
);
2123 dentry
= lookup_hash(&nd
);
2124 error
= PTR_ERR(dentry
);
2125 if (!IS_ERR(dentry
)) {
2126 /* Why not before? Because we want correct error value */
2127 if (nd
.last
.name
[nd
.last
.len
])
2129 inode
= dentry
->d_inode
;
2131 atomic_inc(&inode
->i_count
);
2132 error
= vfs_unlink(nd
.dentry
->d_inode
, dentry
);
2136 mutex_unlock(&nd
.dentry
->d_inode
->i_mutex
);
2138 iput(inode
); /* truncate the inode here */
2146 error
= !dentry
->d_inode
? -ENOENT
:
2147 S_ISDIR(dentry
->d_inode
->i_mode
) ? -EISDIR
: -ENOTDIR
;
2151 asmlinkage
long sys_unlinkat(int dfd
, const char __user
*pathname
, int flag
)
2153 if ((flag
& ~AT_REMOVEDIR
) != 0)
2156 if (flag
& AT_REMOVEDIR
)
2157 return do_rmdir(dfd
, pathname
);
2159 return do_unlinkat(dfd
, pathname
);
2162 asmlinkage
long sys_unlink(const char __user
*pathname
)
2164 return do_unlinkat(AT_FDCWD
, pathname
);
2167 int vfs_symlink(struct inode
*dir
, struct dentry
*dentry
, const char *oldname
, int mode
)
2169 int error
= may_create(dir
, dentry
, NULL
);
2174 if (!dir
->i_op
|| !dir
->i_op
->symlink
)
2177 error
= security_inode_symlink(dir
, dentry
, oldname
);
2182 error
= dir
->i_op
->symlink(dir
, dentry
, oldname
);
2184 fsnotify_create(dir
, dentry
);
2188 asmlinkage
long sys_symlinkat(const char __user
*oldname
,
2189 int newdfd
, const char __user
*newname
)
2195 from
= getname(oldname
);
2197 return PTR_ERR(from
);
2198 to
= getname(newname
);
2199 error
= PTR_ERR(to
);
2201 struct dentry
*dentry
;
2202 struct nameidata nd
;
2204 error
= do_path_lookup(newdfd
, to
, LOOKUP_PARENT
, &nd
);
2207 dentry
= lookup_create(&nd
, 0);
2208 error
= PTR_ERR(dentry
);
2209 if (!IS_ERR(dentry
)) {
2210 error
= vfs_symlink(nd
.dentry
->d_inode
, dentry
, from
, S_IALLUGO
);
2213 mutex_unlock(&nd
.dentry
->d_inode
->i_mutex
);
2222 asmlinkage
long sys_symlink(const char __user
*oldname
, const char __user
*newname
)
2224 return sys_symlinkat(oldname
, AT_FDCWD
, newname
);
2227 int vfs_link(struct dentry
*old_dentry
, struct inode
*dir
, struct dentry
*new_dentry
)
2229 struct inode
*inode
= old_dentry
->d_inode
;
2235 error
= may_create(dir
, new_dentry
, NULL
);
2239 if (dir
->i_sb
!= inode
->i_sb
)
2243 * A link to an append-only or immutable file cannot be created.
2245 if (IS_APPEND(inode
) || IS_IMMUTABLE(inode
))
2247 if (!dir
->i_op
|| !dir
->i_op
->link
)
2249 if (S_ISDIR(old_dentry
->d_inode
->i_mode
))
2252 error
= security_inode_link(old_dentry
, dir
, new_dentry
);
2256 mutex_lock(&old_dentry
->d_inode
->i_mutex
);
2258 error
= dir
->i_op
->link(old_dentry
, dir
, new_dentry
);
2259 mutex_unlock(&old_dentry
->d_inode
->i_mutex
);
2261 fsnotify_create(dir
, new_dentry
);
2266 * Hardlinks are often used in delicate situations. We avoid
2267 * security-related surprises by not following symlinks on the
2270 * We don't follow them on the oldname either to be compatible
2271 * with linux 2.0, and to avoid hard-linking to directories
2272 * and other special files. --ADM
2274 asmlinkage
long sys_linkat(int olddfd
, const char __user
*oldname
,
2275 int newdfd
, const char __user
*newname
,
2278 struct dentry
*new_dentry
;
2279 struct nameidata nd
, old_nd
;
2283 if ((flags
& ~AT_SYMLINK_FOLLOW
) != 0)
2286 to
= getname(newname
);
2290 error
= __user_walk_fd(olddfd
, oldname
,
2291 flags
& AT_SYMLINK_FOLLOW
? LOOKUP_FOLLOW
: 0,
2295 error
= do_path_lookup(newdfd
, to
, LOOKUP_PARENT
, &nd
);
2299 if (old_nd
.mnt
!= nd
.mnt
)
2301 new_dentry
= lookup_create(&nd
, 0);
2302 error
= PTR_ERR(new_dentry
);
2303 if (!IS_ERR(new_dentry
)) {
2304 error
= vfs_link(old_nd
.dentry
, nd
.dentry
->d_inode
, new_dentry
);
2307 mutex_unlock(&nd
.dentry
->d_inode
->i_mutex
);
2311 path_release(&old_nd
);
2318 asmlinkage
long sys_link(const char __user
*oldname
, const char __user
*newname
)
2320 return sys_linkat(AT_FDCWD
, oldname
, AT_FDCWD
, newname
, 0);
2324 * The worst of all namespace operations - renaming directory. "Perverted"
2325 * doesn't even start to describe it. Somebody in UCB had a heck of a trip...
2327 * a) we can get into loop creation. Check is done in is_subdir().
2328 * b) race potential - two innocent renames can create a loop together.
2329 * That's where 4.4 screws up. Current fix: serialization on
2330 * sb->s_vfs_rename_mutex. We might be more accurate, but that's another
2332 * c) we have to lock _three_ objects - parents and victim (if it exists).
2333 * And that - after we got ->i_mutex on parents (until then we don't know
2334 * whether the target exists). Solution: try to be smart with locking
2335 * order for inodes. We rely on the fact that tree topology may change
2336 * only under ->s_vfs_rename_mutex _and_ that parent of the object we
2337 * move will be locked. Thus we can rank directories by the tree
2338 * (ancestors first) and rank all non-directories after them.
2339 * That works since everybody except rename does "lock parent, lookup,
2340 * lock child" and rename is under ->s_vfs_rename_mutex.
2341 * HOWEVER, it relies on the assumption that any object with ->lookup()
2342 * has no more than 1 dentry. If "hybrid" objects will ever appear,
2343 * we'd better make sure that there's no link(2) for them.
2344 * d) some filesystems don't support opened-but-unlinked directories,
2345 * either because of layout or because they are not ready to deal with
2346 * all cases correctly. The latter will be fixed (taking this sort of
2347 * stuff into VFS), but the former is not going away. Solution: the same
2348 * trick as in rmdir().
2349 * e) conversion from fhandle to dentry may come in the wrong moment - when
2350 * we are removing the target. Solution: we will have to grab ->i_mutex
2351 * in the fhandle_to_dentry code. [FIXME - current nfsfh.c relies on
2352 * ->i_mutex on parents, which works but leads to some truely excessive
2355 static int vfs_rename_dir(struct inode
*old_dir
, struct dentry
*old_dentry
,
2356 struct inode
*new_dir
, struct dentry
*new_dentry
)
2359 struct inode
*target
;
2362 * If we are going to change the parent - check write permissions,
2363 * we'll need to flip '..'.
2365 if (new_dir
!= old_dir
) {
2366 error
= permission(old_dentry
->d_inode
, MAY_WRITE
, NULL
);
2371 error
= security_inode_rename(old_dir
, old_dentry
, new_dir
, new_dentry
);
2375 target
= new_dentry
->d_inode
;
2377 mutex_lock(&target
->i_mutex
);
2378 dentry_unhash(new_dentry
);
2380 if (d_mountpoint(old_dentry
)||d_mountpoint(new_dentry
))
2383 error
= old_dir
->i_op
->rename(old_dir
, old_dentry
, new_dir
, new_dentry
);
2386 target
->i_flags
|= S_DEAD
;
2387 mutex_unlock(&target
->i_mutex
);
2388 if (d_unhashed(new_dentry
))
2389 d_rehash(new_dentry
);
2393 if (!(old_dir
->i_sb
->s_type
->fs_flags
& FS_RENAME_DOES_D_MOVE
))
2394 d_move(old_dentry
,new_dentry
);
2398 static int vfs_rename_other(struct inode
*old_dir
, struct dentry
*old_dentry
,
2399 struct inode
*new_dir
, struct dentry
*new_dentry
)
2401 struct inode
*target
;
2404 error
= security_inode_rename(old_dir
, old_dentry
, new_dir
, new_dentry
);
2409 target
= new_dentry
->d_inode
;
2411 mutex_lock(&target
->i_mutex
);
2412 if (d_mountpoint(old_dentry
)||d_mountpoint(new_dentry
))
2415 error
= old_dir
->i_op
->rename(old_dir
, old_dentry
, new_dir
, new_dentry
);
2417 if (!(old_dir
->i_sb
->s_type
->fs_flags
& FS_RENAME_DOES_D_MOVE
))
2418 d_move(old_dentry
, new_dentry
);
2421 mutex_unlock(&target
->i_mutex
);
2426 int vfs_rename(struct inode
*old_dir
, struct dentry
*old_dentry
,
2427 struct inode
*new_dir
, struct dentry
*new_dentry
)
2430 int is_dir
= S_ISDIR(old_dentry
->d_inode
->i_mode
);
2431 const char *old_name
;
2433 if (old_dentry
->d_inode
== new_dentry
->d_inode
)
2436 error
= may_delete(old_dir
, old_dentry
, is_dir
);
2440 if (!new_dentry
->d_inode
)
2441 error
= may_create(new_dir
, new_dentry
, NULL
);
2443 error
= may_delete(new_dir
, new_dentry
, is_dir
);
2447 if (!old_dir
->i_op
|| !old_dir
->i_op
->rename
)
2450 DQUOT_INIT(old_dir
);
2451 DQUOT_INIT(new_dir
);
2453 old_name
= fsnotify_oldname_init(old_dentry
->d_name
.name
);
2456 error
= vfs_rename_dir(old_dir
,old_dentry
,new_dir
,new_dentry
);
2458 error
= vfs_rename_other(old_dir
,old_dentry
,new_dir
,new_dentry
);
2460 const char *new_name
= old_dentry
->d_name
.name
;
2461 fsnotify_move(old_dir
, new_dir
, old_name
, new_name
, is_dir
,
2462 new_dentry
->d_inode
, old_dentry
->d_inode
);
2464 fsnotify_oldname_free(old_name
);
2469 static int do_rename(int olddfd
, const char *oldname
,
2470 int newdfd
, const char *newname
)
2473 struct dentry
* old_dir
, * new_dir
;
2474 struct dentry
* old_dentry
, *new_dentry
;
2475 struct dentry
* trap
;
2476 struct nameidata oldnd
, newnd
;
2478 error
= do_path_lookup(olddfd
, oldname
, LOOKUP_PARENT
, &oldnd
);
2482 error
= do_path_lookup(newdfd
, newname
, LOOKUP_PARENT
, &newnd
);
2487 if (oldnd
.mnt
!= newnd
.mnt
)
2490 old_dir
= oldnd
.dentry
;
2492 if (oldnd
.last_type
!= LAST_NORM
)
2495 new_dir
= newnd
.dentry
;
2496 if (newnd
.last_type
!= LAST_NORM
)
2499 trap
= lock_rename(new_dir
, old_dir
);
2501 old_dentry
= lookup_hash(&oldnd
);
2502 error
= PTR_ERR(old_dentry
);
2503 if (IS_ERR(old_dentry
))
2505 /* source must exist */
2507 if (!old_dentry
->d_inode
)
2509 /* unless the source is a directory trailing slashes give -ENOTDIR */
2510 if (!S_ISDIR(old_dentry
->d_inode
->i_mode
)) {
2512 if (oldnd
.last
.name
[oldnd
.last
.len
])
2514 if (newnd
.last
.name
[newnd
.last
.len
])
2517 /* source should not be ancestor of target */
2519 if (old_dentry
== trap
)
2521 new_dentry
= lookup_hash(&newnd
);
2522 error
= PTR_ERR(new_dentry
);
2523 if (IS_ERR(new_dentry
))
2525 /* target should not be an ancestor of source */
2527 if (new_dentry
== trap
)
2530 error
= vfs_rename(old_dir
->d_inode
, old_dentry
,
2531 new_dir
->d_inode
, new_dentry
);
2537 unlock_rename(new_dir
, old_dir
);
2539 path_release(&newnd
);
2541 path_release(&oldnd
);
2546 asmlinkage
long sys_renameat(int olddfd
, const char __user
*oldname
,
2547 int newdfd
, const char __user
*newname
)
2553 from
= getname(oldname
);
2555 return PTR_ERR(from
);
2556 to
= getname(newname
);
2557 error
= PTR_ERR(to
);
2559 error
= do_rename(olddfd
, from
, newdfd
, to
);
2566 asmlinkage
long sys_rename(const char __user
*oldname
, const char __user
*newname
)
2568 return sys_renameat(AT_FDCWD
, oldname
, AT_FDCWD
, newname
);
2571 int vfs_readlink(struct dentry
*dentry
, char __user
*buffer
, int buflen
, const char *link
)
2575 len
= PTR_ERR(link
);
2580 if (len
> (unsigned) buflen
)
2582 if (copy_to_user(buffer
, link
, len
))
2589 * A helper for ->readlink(). This should be used *ONLY* for symlinks that
2590 * have ->follow_link() touching nd only in nd_set_link(). Using (or not
2591 * using) it for any given inode is up to filesystem.
2593 int generic_readlink(struct dentry
*dentry
, char __user
*buffer
, int buflen
)
2595 struct nameidata nd
;
2599 cookie
= dentry
->d_inode
->i_op
->follow_link(dentry
, &nd
);
2600 if (!IS_ERR(cookie
)) {
2601 int res
= vfs_readlink(dentry
, buffer
, buflen
, nd_get_link(&nd
));
2602 if (dentry
->d_inode
->i_op
->put_link
)
2603 dentry
->d_inode
->i_op
->put_link(dentry
, &nd
, cookie
);
2604 cookie
= ERR_PTR(res
);
2606 return PTR_ERR(cookie
);
2609 int vfs_follow_link(struct nameidata
*nd
, const char *link
)
2611 return __vfs_follow_link(nd
, link
);
2614 /* get the link contents into pagecache */
2615 static char *page_getlink(struct dentry
* dentry
, struct page
**ppage
)
2618 struct address_space
*mapping
= dentry
->d_inode
->i_mapping
;
2619 page
= read_mapping_page(mapping
, 0, NULL
);
2622 wait_on_page_locked(page
);
2623 if (!PageUptodate(page
))
2629 page_cache_release(page
);
2630 return ERR_PTR(-EIO
);
2636 int page_readlink(struct dentry
*dentry
, char __user
*buffer
, int buflen
)
2638 struct page
*page
= NULL
;
2639 char *s
= page_getlink(dentry
, &page
);
2640 int res
= vfs_readlink(dentry
,buffer
,buflen
,s
);
2643 page_cache_release(page
);
2648 void *page_follow_link_light(struct dentry
*dentry
, struct nameidata
*nd
)
2650 struct page
*page
= NULL
;
2651 nd_set_link(nd
, page_getlink(dentry
, &page
));
2655 void page_put_link(struct dentry
*dentry
, struct nameidata
*nd
, void *cookie
)
2657 struct page
*page
= cookie
;
2661 page_cache_release(page
);
2665 int __page_symlink(struct inode
*inode
, const char *symname
, int len
,
2668 struct address_space
*mapping
= inode
->i_mapping
;
2674 page
= find_or_create_page(mapping
, 0, gfp_mask
);
2677 err
= mapping
->a_ops
->prepare_write(NULL
, page
, 0, len
-1);
2678 if (err
== AOP_TRUNCATED_PAGE
) {
2679 page_cache_release(page
);
2684 kaddr
= kmap_atomic(page
, KM_USER0
);
2685 memcpy(kaddr
, symname
, len
-1);
2686 kunmap_atomic(kaddr
, KM_USER0
);
2687 err
= mapping
->a_ops
->commit_write(NULL
, page
, 0, len
-1);
2688 if (err
== AOP_TRUNCATED_PAGE
) {
2689 page_cache_release(page
);
2695 * Notice that we are _not_ going to block here - end of page is
2696 * unmapped, so this will only try to map the rest of page, see
2697 * that it is unmapped (typically even will not look into inode -
2698 * ->i_size will be enough for everything) and zero it out.
2699 * OTOH it's obviously correct and should make the page up-to-date.
2701 if (!PageUptodate(page
)) {
2702 err
= mapping
->a_ops
->readpage(NULL
, page
);
2703 if (err
!= AOP_TRUNCATED_PAGE
)
2704 wait_on_page_locked(page
);
2708 page_cache_release(page
);
2711 mark_inode_dirty(inode
);
2715 page_cache_release(page
);
2720 int page_symlink(struct inode
*inode
, const char *symname
, int len
)
2722 return __page_symlink(inode
, symname
, len
,
2723 mapping_gfp_mask(inode
->i_mapping
));
2726 struct inode_operations page_symlink_inode_operations
= {
2727 .readlink
= generic_readlink
,
2728 .follow_link
= page_follow_link_light
,
2729 .put_link
= page_put_link
,
2732 EXPORT_SYMBOL(__user_walk
);
2733 EXPORT_SYMBOL(__user_walk_fd
);
2734 EXPORT_SYMBOL(follow_down
);
2735 EXPORT_SYMBOL(follow_up
);
2736 EXPORT_SYMBOL(get_write_access
); /* binfmt_aout */
2737 EXPORT_SYMBOL(getname
);
2738 EXPORT_SYMBOL(lock_rename
);
2739 EXPORT_SYMBOL(lookup_one_len
);
2740 EXPORT_SYMBOL(page_follow_link_light
);
2741 EXPORT_SYMBOL(page_put_link
);
2742 EXPORT_SYMBOL(page_readlink
);
2743 EXPORT_SYMBOL(__page_symlink
);
2744 EXPORT_SYMBOL(page_symlink
);
2745 EXPORT_SYMBOL(page_symlink_inode_operations
);
2746 EXPORT_SYMBOL(path_lookup
);
2747 EXPORT_SYMBOL(path_release
);
2748 EXPORT_SYMBOL(path_walk
);
2749 EXPORT_SYMBOL(permission
);
2750 EXPORT_SYMBOL(vfs_permission
);
2751 EXPORT_SYMBOL(file_permission
);
2752 EXPORT_SYMBOL(unlock_rename
);
2753 EXPORT_SYMBOL(vfs_create
);
2754 EXPORT_SYMBOL(vfs_follow_link
);
2755 EXPORT_SYMBOL(vfs_link
);
2756 EXPORT_SYMBOL(vfs_mkdir
);
2757 EXPORT_SYMBOL(vfs_mknod
);
2758 EXPORT_SYMBOL(generic_permission
);
2759 EXPORT_SYMBOL(vfs_readlink
);
2760 EXPORT_SYMBOL(vfs_rename
);
2761 EXPORT_SYMBOL(vfs_rmdir
);
2762 EXPORT_SYMBOL(vfs_symlink
);
2763 EXPORT_SYMBOL(vfs_unlink
);
2764 EXPORT_SYMBOL(dentry_unhash
);
2765 EXPORT_SYMBOL(generic_readlink
);