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 struct fs_struct
*fs
= current
->fs
;
523 read_lock(&fs
->lock
);
524 if (fs
->altroot
&& !(nd
->flags
& LOOKUP_NOALT
)) {
525 nd
->mnt
= mntget(fs
->altrootmnt
);
526 nd
->dentry
= dget(fs
->altroot
);
527 read_unlock(&fs
->lock
);
528 if (__emul_lookup_dentry(name
,nd
))
530 read_lock(&fs
->lock
);
532 nd
->mnt
= mntget(fs
->rootmnt
);
533 nd
->dentry
= dget(fs
->root
);
534 read_unlock(&fs
->lock
);
538 static __always_inline
int __vfs_follow_link(struct nameidata
*nd
, const char *link
)
547 if (!walk_init_root(link
, nd
))
548 /* weird __emul_prefix() stuff did it */
551 res
= link_path_walk(link
, nd
);
553 if (nd
->depth
|| res
|| nd
->last_type
!=LAST_NORM
)
556 * If it is an iterative symlinks resolution in open_namei() we
557 * have to copy the last component. And all that crap because of
558 * bloody create() on broken symlinks. Furrfu...
561 if (unlikely(!name
)) {
565 strcpy(name
, nd
->last
.name
);
566 nd
->last
.name
= name
;
570 return PTR_ERR(link
);
574 struct vfsmount
*mnt
;
575 struct dentry
*dentry
;
578 static inline void dput_path(struct path
*path
, struct nameidata
*nd
)
581 if (path
->mnt
!= nd
->mnt
)
585 static inline void path_to_nameidata(struct path
*path
, struct nameidata
*nd
)
588 if (nd
->mnt
!= path
->mnt
)
591 nd
->dentry
= path
->dentry
;
594 static __always_inline
int __do_follow_link(struct path
*path
, struct nameidata
*nd
)
598 struct dentry
*dentry
= path
->dentry
;
600 touch_atime(path
->mnt
, dentry
);
601 nd_set_link(nd
, NULL
);
603 if (path
->mnt
!= nd
->mnt
) {
604 path_to_nameidata(path
, nd
);
608 cookie
= dentry
->d_inode
->i_op
->follow_link(dentry
, nd
);
609 error
= PTR_ERR(cookie
);
610 if (!IS_ERR(cookie
)) {
611 char *s
= nd_get_link(nd
);
614 error
= __vfs_follow_link(nd
, s
);
615 if (dentry
->d_inode
->i_op
->put_link
)
616 dentry
->d_inode
->i_op
->put_link(dentry
, nd
, cookie
);
625 * This limits recursive symlink follows to 8, while
626 * limiting consecutive symlinks to 40.
628 * Without that kind of total limit, nasty chains of consecutive
629 * symlinks can cause almost arbitrarily long lookups.
631 static inline int do_follow_link(struct path
*path
, struct nameidata
*nd
)
634 if (current
->link_count
>= MAX_NESTED_LINKS
)
636 if (current
->total_link_count
>= 40)
638 BUG_ON(nd
->depth
>= MAX_NESTED_LINKS
);
640 err
= security_inode_follow_link(path
->dentry
, nd
);
643 current
->link_count
++;
644 current
->total_link_count
++;
646 err
= __do_follow_link(path
, nd
);
647 current
->link_count
--;
656 int follow_up(struct vfsmount
**mnt
, struct dentry
**dentry
)
658 struct vfsmount
*parent
;
659 struct dentry
*mountpoint
;
660 spin_lock(&vfsmount_lock
);
661 parent
=(*mnt
)->mnt_parent
;
662 if (parent
== *mnt
) {
663 spin_unlock(&vfsmount_lock
);
667 mountpoint
=dget((*mnt
)->mnt_mountpoint
);
668 spin_unlock(&vfsmount_lock
);
670 *dentry
= mountpoint
;
676 /* no need for dcache_lock, as serialization is taken care in
679 static int __follow_mount(struct path
*path
)
682 while (d_mountpoint(path
->dentry
)) {
683 struct vfsmount
*mounted
= lookup_mnt(path
->mnt
, path
->dentry
);
690 path
->dentry
= dget(mounted
->mnt_root
);
696 static void follow_mount(struct vfsmount
**mnt
, struct dentry
**dentry
)
698 while (d_mountpoint(*dentry
)) {
699 struct vfsmount
*mounted
= lookup_mnt(*mnt
, *dentry
);
705 *dentry
= dget(mounted
->mnt_root
);
709 /* no need for dcache_lock, as serialization is taken care in
712 int follow_down(struct vfsmount
**mnt
, struct dentry
**dentry
)
714 struct vfsmount
*mounted
;
716 mounted
= lookup_mnt(*mnt
, *dentry
);
721 *dentry
= dget(mounted
->mnt_root
);
727 static __always_inline
void follow_dotdot(struct nameidata
*nd
)
729 struct fs_struct
*fs
= current
->fs
;
732 struct vfsmount
*parent
;
733 struct dentry
*old
= nd
->dentry
;
735 read_lock(&fs
->lock
);
736 if (nd
->dentry
== fs
->root
&&
737 nd
->mnt
== fs
->rootmnt
) {
738 read_unlock(&fs
->lock
);
741 read_unlock(&fs
->lock
);
742 spin_lock(&dcache_lock
);
743 if (nd
->dentry
!= nd
->mnt
->mnt_root
) {
744 nd
->dentry
= dget(nd
->dentry
->d_parent
);
745 spin_unlock(&dcache_lock
);
749 spin_unlock(&dcache_lock
);
750 spin_lock(&vfsmount_lock
);
751 parent
= nd
->mnt
->mnt_parent
;
752 if (parent
== nd
->mnt
) {
753 spin_unlock(&vfsmount_lock
);
757 nd
->dentry
= dget(nd
->mnt
->mnt_mountpoint
);
758 spin_unlock(&vfsmount_lock
);
763 follow_mount(&nd
->mnt
, &nd
->dentry
);
767 * It's more convoluted than I'd like it to be, but... it's still fairly
768 * small and for now I'd prefer to have fast path as straight as possible.
769 * It _is_ time-critical.
771 static int do_lookup(struct nameidata
*nd
, struct qstr
*name
,
774 struct vfsmount
*mnt
= nd
->mnt
;
775 struct dentry
*dentry
= __d_lookup(nd
->dentry
, name
);
779 if (dentry
->d_op
&& dentry
->d_op
->d_revalidate
)
780 goto need_revalidate
;
783 path
->dentry
= dentry
;
784 __follow_mount(path
);
788 dentry
= real_lookup(nd
->dentry
, name
, nd
);
794 dentry
= do_revalidate(dentry
, nd
);
802 return PTR_ERR(dentry
);
807 * This is the basic name resolution function, turning a pathname into
808 * the final dentry. We expect 'base' to be positive and a directory.
810 * Returns 0 and nd will have valid dentry and mnt on success.
811 * Returns error and drops reference to input namei data on failure.
813 static fastcall
int __link_path_walk(const char * name
, struct nameidata
*nd
)
818 unsigned int lookup_flags
= nd
->flags
;
825 inode
= nd
->dentry
->d_inode
;
827 lookup_flags
= LOOKUP_FOLLOW
| (nd
->flags
& LOOKUP_CONTINUE
);
829 /* At this point we know we have a real path component. */
835 nd
->flags
|= LOOKUP_CONTINUE
;
836 err
= exec_permission_lite(inode
, nd
);
838 err
= vfs_permission(nd
, MAY_EXEC
);
843 c
= *(const unsigned char *)name
;
845 hash
= init_name_hash();
848 hash
= partial_name_hash(c
, hash
);
849 c
= *(const unsigned char *)name
;
850 } while (c
&& (c
!= '/'));
851 this.len
= name
- (const char *) this.name
;
852 this.hash
= end_name_hash(hash
);
854 /* remove trailing slashes? */
857 while (*++name
== '/');
859 goto last_with_slashes
;
862 * "." and ".." are special - ".." especially so because it has
863 * to be able to know about the current root directory and
864 * parent relationships.
866 if (this.name
[0] == '.') switch (this.len
) {
870 if (this.name
[1] != '.')
873 inode
= nd
->dentry
->d_inode
;
879 * See if the low-level filesystem might want
880 * to use its own hash..
882 if (nd
->dentry
->d_op
&& nd
->dentry
->d_op
->d_hash
) {
883 err
= nd
->dentry
->d_op
->d_hash(nd
->dentry
, &this);
887 /* This does the actual lookups.. */
888 err
= do_lookup(nd
, &this, &next
);
893 inode
= next
.dentry
->d_inode
;
900 if (inode
->i_op
->follow_link
) {
901 err
= do_follow_link(&next
, nd
);
905 inode
= nd
->dentry
->d_inode
;
912 path_to_nameidata(&next
, nd
);
914 if (!inode
->i_op
->lookup
)
917 /* here ends the main loop */
920 lookup_flags
|= LOOKUP_FOLLOW
| LOOKUP_DIRECTORY
;
922 /* Clear LOOKUP_CONTINUE iff it was previously unset */
923 nd
->flags
&= lookup_flags
| ~LOOKUP_CONTINUE
;
924 if (lookup_flags
& LOOKUP_PARENT
)
926 if (this.name
[0] == '.') switch (this.len
) {
930 if (this.name
[1] != '.')
933 inode
= nd
->dentry
->d_inode
;
938 if (nd
->dentry
->d_op
&& nd
->dentry
->d_op
->d_hash
) {
939 err
= nd
->dentry
->d_op
->d_hash(nd
->dentry
, &this);
943 err
= do_lookup(nd
, &this, &next
);
946 inode
= next
.dentry
->d_inode
;
947 if ((lookup_flags
& LOOKUP_FOLLOW
)
948 && inode
&& inode
->i_op
&& inode
->i_op
->follow_link
) {
949 err
= do_follow_link(&next
, nd
);
952 inode
= nd
->dentry
->d_inode
;
954 path_to_nameidata(&next
, nd
);
958 if (lookup_flags
& LOOKUP_DIRECTORY
) {
960 if (!inode
->i_op
|| !inode
->i_op
->lookup
)
966 nd
->last_type
= LAST_NORM
;
967 if (this.name
[0] != '.')
970 nd
->last_type
= LAST_DOT
;
971 else if (this.len
== 2 && this.name
[1] == '.')
972 nd
->last_type
= LAST_DOTDOT
;
977 * We bypassed the ordinary revalidation routines.
978 * We may need to check the cached dentry for staleness.
980 if (nd
->dentry
&& nd
->dentry
->d_sb
&&
981 (nd
->dentry
->d_sb
->s_type
->fs_flags
& FS_REVAL_DOT
)) {
983 /* Note: we do not d_invalidate() */
984 if (!nd
->dentry
->d_op
->d_revalidate(nd
->dentry
, nd
))
990 dput_path(&next
, nd
);
999 * Wrapper to retry pathname resolution whenever the underlying
1000 * file system returns an ESTALE.
1002 * Retry the whole path once, forcing real lookup requests
1003 * instead of relying on the dcache.
1005 int fastcall
link_path_walk(const char *name
, struct nameidata
*nd
)
1007 struct nameidata save
= *nd
;
1010 /* make sure the stuff we saved doesn't go away */
1014 result
= __link_path_walk(name
, nd
);
1015 if (result
== -ESTALE
) {
1019 nd
->flags
|= LOOKUP_REVAL
;
1020 result
= __link_path_walk(name
, nd
);
1029 int fastcall
path_walk(const char * name
, struct nameidata
*nd
)
1031 current
->total_link_count
= 0;
1032 return link_path_walk(name
, nd
);
1036 * SMP-safe: Returns 1 and nd will have valid dentry and mnt, if
1037 * everything is done. Returns 0 and drops input nd, if lookup failed;
1039 static int __emul_lookup_dentry(const char *name
, struct nameidata
*nd
)
1041 if (path_walk(name
, nd
))
1042 return 0; /* something went wrong... */
1044 if (!nd
->dentry
->d_inode
|| S_ISDIR(nd
->dentry
->d_inode
->i_mode
)) {
1045 struct dentry
*old_dentry
= nd
->dentry
;
1046 struct vfsmount
*old_mnt
= nd
->mnt
;
1047 struct qstr last
= nd
->last
;
1048 int last_type
= nd
->last_type
;
1049 struct fs_struct
*fs
= current
->fs
;
1052 * NAME was not found in alternate root or it's a directory.
1053 * Try to find it in the normal root:
1055 nd
->last_type
= LAST_ROOT
;
1056 read_lock(&fs
->lock
);
1057 nd
->mnt
= mntget(fs
->rootmnt
);
1058 nd
->dentry
= dget(fs
->root
);
1059 read_unlock(&fs
->lock
);
1060 if (path_walk(name
, nd
) == 0) {
1061 if (nd
->dentry
->d_inode
) {
1068 nd
->dentry
= old_dentry
;
1071 nd
->last_type
= last_type
;
1076 void set_fs_altroot(void)
1078 char *emul
= __emul_prefix();
1079 struct nameidata nd
;
1080 struct vfsmount
*mnt
= NULL
, *oldmnt
;
1081 struct dentry
*dentry
= NULL
, *olddentry
;
1083 struct fs_struct
*fs
= current
->fs
;
1087 err
= path_lookup(emul
, LOOKUP_FOLLOW
|LOOKUP_DIRECTORY
|LOOKUP_NOALT
, &nd
);
1093 write_lock(&fs
->lock
);
1094 oldmnt
= fs
->altrootmnt
;
1095 olddentry
= fs
->altroot
;
1096 fs
->altrootmnt
= mnt
;
1097 fs
->altroot
= dentry
;
1098 write_unlock(&fs
->lock
);
1105 /* Returns 0 and nd will be valid on success; Retuns error, otherwise. */
1106 static int fastcall
do_path_lookup(int dfd
, const char *name
,
1107 unsigned int flags
, struct nameidata
*nd
)
1112 struct fs_struct
*fs
= current
->fs
;
1114 nd
->last_type
= LAST_ROOT
; /* if there are only slashes... */
1119 read_lock(&fs
->lock
);
1120 if (fs
->altroot
&& !(nd
->flags
& LOOKUP_NOALT
)) {
1121 nd
->mnt
= mntget(fs
->altrootmnt
);
1122 nd
->dentry
= dget(fs
->altroot
);
1123 read_unlock(&fs
->lock
);
1124 if (__emul_lookup_dentry(name
,nd
))
1125 goto out
; /* found in altroot */
1126 read_lock(&fs
->lock
);
1128 nd
->mnt
= mntget(fs
->rootmnt
);
1129 nd
->dentry
= dget(fs
->root
);
1130 read_unlock(&fs
->lock
);
1131 } else if (dfd
== AT_FDCWD
) {
1132 read_lock(&fs
->lock
);
1133 nd
->mnt
= mntget(fs
->pwdmnt
);
1134 nd
->dentry
= dget(fs
->pwd
);
1135 read_unlock(&fs
->lock
);
1137 struct dentry
*dentry
;
1139 file
= fget_light(dfd
, &fput_needed
);
1144 dentry
= file
->f_dentry
;
1147 if (!S_ISDIR(dentry
->d_inode
->i_mode
))
1150 retval
= file_permission(file
, MAY_EXEC
);
1154 nd
->mnt
= mntget(file
->f_vfsmnt
);
1155 nd
->dentry
= dget(dentry
);
1157 fput_light(file
, fput_needed
);
1159 current
->total_link_count
= 0;
1160 retval
= link_path_walk(name
, nd
);
1162 if (likely(retval
== 0)) {
1163 if (unlikely(!audit_dummy_context() && nd
&& nd
->dentry
&&
1164 nd
->dentry
->d_inode
))
1165 audit_inode(name
, nd
->dentry
->d_inode
);
1171 fput_light(file
, fput_needed
);
1175 int fastcall
path_lookup(const char *name
, unsigned int flags
,
1176 struct nameidata
*nd
)
1178 return do_path_lookup(AT_FDCWD
, name
, flags
, nd
);
1181 static int __path_lookup_intent_open(int dfd
, const char *name
,
1182 unsigned int lookup_flags
, struct nameidata
*nd
,
1183 int open_flags
, int create_mode
)
1185 struct file
*filp
= get_empty_filp();
1190 nd
->intent
.open
.file
= filp
;
1191 nd
->intent
.open
.flags
= open_flags
;
1192 nd
->intent
.open
.create_mode
= create_mode
;
1193 err
= do_path_lookup(dfd
, name
, lookup_flags
|LOOKUP_OPEN
, nd
);
1194 if (IS_ERR(nd
->intent
.open
.file
)) {
1196 err
= PTR_ERR(nd
->intent
.open
.file
);
1199 } else if (err
!= 0)
1200 release_open_intent(nd
);
1205 * path_lookup_open - lookup a file path with open intent
1206 * @dfd: the directory to use as base, or AT_FDCWD
1207 * @name: pointer to file name
1208 * @lookup_flags: lookup intent flags
1209 * @nd: pointer to nameidata
1210 * @open_flags: open intent flags
1212 int path_lookup_open(int dfd
, const char *name
, unsigned int lookup_flags
,
1213 struct nameidata
*nd
, int open_flags
)
1215 return __path_lookup_intent_open(dfd
, name
, lookup_flags
, nd
,
1220 * path_lookup_create - lookup a file path with open + create intent
1221 * @dfd: the directory to use as base, or AT_FDCWD
1222 * @name: pointer to file name
1223 * @lookup_flags: lookup intent flags
1224 * @nd: pointer to nameidata
1225 * @open_flags: open intent flags
1226 * @create_mode: create intent flags
1228 static int path_lookup_create(int dfd
, const char *name
,
1229 unsigned int lookup_flags
, struct nameidata
*nd
,
1230 int open_flags
, int create_mode
)
1232 return __path_lookup_intent_open(dfd
, name
, lookup_flags
|LOOKUP_CREATE
,
1233 nd
, open_flags
, create_mode
);
1236 int __user_path_lookup_open(const char __user
*name
, unsigned int lookup_flags
,
1237 struct nameidata
*nd
, int open_flags
)
1239 char *tmp
= getname(name
);
1240 int err
= PTR_ERR(tmp
);
1243 err
= __path_lookup_intent_open(AT_FDCWD
, tmp
, lookup_flags
, nd
, open_flags
, 0);
1250 * Restricted form of lookup. Doesn't follow links, single-component only,
1251 * needs parent already locked. Doesn't follow mounts.
1254 static struct dentry
* __lookup_hash(struct qstr
*name
, struct dentry
* base
, struct nameidata
*nd
)
1256 struct dentry
* dentry
;
1257 struct inode
*inode
;
1260 inode
= base
->d_inode
;
1261 err
= permission(inode
, MAY_EXEC
, nd
);
1262 dentry
= ERR_PTR(err
);
1267 * See if the low-level filesystem might want
1268 * to use its own hash..
1270 if (base
->d_op
&& base
->d_op
->d_hash
) {
1271 err
= base
->d_op
->d_hash(base
, name
);
1272 dentry
= ERR_PTR(err
);
1277 dentry
= cached_lookup(base
, name
, nd
);
1279 struct dentry
*new = d_alloc(base
, name
);
1280 dentry
= ERR_PTR(-ENOMEM
);
1283 dentry
= inode
->i_op
->lookup(inode
, new, nd
);
1293 static struct dentry
*lookup_hash(struct nameidata
*nd
)
1295 return __lookup_hash(&nd
->last
, nd
->dentry
, nd
);
1299 struct dentry
* lookup_one_len(const char * name
, struct dentry
* base
, int len
)
1310 hash
= init_name_hash();
1312 c
= *(const unsigned char *)name
++;
1313 if (c
== '/' || c
== '\0')
1315 hash
= partial_name_hash(c
, hash
);
1317 this.hash
= end_name_hash(hash
);
1319 return __lookup_hash(&this, base
, NULL
);
1321 return ERR_PTR(-EACCES
);
1327 * is used by most simple commands to get the inode of a specified name.
1328 * Open, link etc use their own routines, but this is enough for things
1331 * namei exists in two versions: namei/lnamei. The only difference is
1332 * that namei follows links, while lnamei does not.
1335 int fastcall
__user_walk_fd(int dfd
, const char __user
*name
, unsigned flags
,
1336 struct nameidata
*nd
)
1338 char *tmp
= getname(name
);
1339 int err
= PTR_ERR(tmp
);
1342 err
= do_path_lookup(dfd
, tmp
, flags
, nd
);
1348 int fastcall
__user_walk(const char __user
*name
, unsigned flags
, struct nameidata
*nd
)
1350 return __user_walk_fd(AT_FDCWD
, name
, flags
, nd
);
1354 * It's inline, so penalty for filesystems that don't use sticky bit is
1357 static inline int check_sticky(struct inode
*dir
, struct inode
*inode
)
1359 if (!(dir
->i_mode
& S_ISVTX
))
1361 if (inode
->i_uid
== current
->fsuid
)
1363 if (dir
->i_uid
== current
->fsuid
)
1365 return !capable(CAP_FOWNER
);
1369 * Check whether we can remove a link victim from directory dir, check
1370 * whether the type of victim is right.
1371 * 1. We can't do it if dir is read-only (done in permission())
1372 * 2. We should have write and exec permissions on dir
1373 * 3. We can't remove anything from append-only dir
1374 * 4. We can't do anything with immutable dir (done in permission())
1375 * 5. If the sticky bit on dir is set we should either
1376 * a. be owner of dir, or
1377 * b. be owner of victim, or
1378 * c. have CAP_FOWNER capability
1379 * 6. If the victim is append-only or immutable we can't do antyhing with
1380 * links pointing to it.
1381 * 7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
1382 * 8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
1383 * 9. We can't remove a root or mountpoint.
1384 * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
1385 * nfs_async_unlink().
1387 static int may_delete(struct inode
*dir
,struct dentry
*victim
,int isdir
)
1391 if (!victim
->d_inode
)
1394 BUG_ON(victim
->d_parent
->d_inode
!= dir
);
1395 audit_inode_child(victim
->d_name
.name
, victim
->d_inode
, dir
);
1397 error
= permission(dir
,MAY_WRITE
| MAY_EXEC
, NULL
);
1402 if (check_sticky(dir
, victim
->d_inode
)||IS_APPEND(victim
->d_inode
)||
1403 IS_IMMUTABLE(victim
->d_inode
))
1406 if (!S_ISDIR(victim
->d_inode
->i_mode
))
1408 if (IS_ROOT(victim
))
1410 } else if (S_ISDIR(victim
->d_inode
->i_mode
))
1412 if (IS_DEADDIR(dir
))
1414 if (victim
->d_flags
& DCACHE_NFSFS_RENAMED
)
1419 /* Check whether we can create an object with dentry child in directory
1421 * 1. We can't do it if child already exists (open has special treatment for
1422 * this case, but since we are inlined it's OK)
1423 * 2. We can't do it if dir is read-only (done in permission())
1424 * 3. We should have write and exec permissions on dir
1425 * 4. We can't do it if dir is immutable (done in permission())
1427 static inline int may_create(struct inode
*dir
, struct dentry
*child
,
1428 struct nameidata
*nd
)
1432 if (IS_DEADDIR(dir
))
1434 return permission(dir
,MAY_WRITE
| MAY_EXEC
, nd
);
1438 * O_DIRECTORY translates into forcing a directory lookup.
1440 static inline int lookup_flags(unsigned int f
)
1442 unsigned long retval
= LOOKUP_FOLLOW
;
1445 retval
&= ~LOOKUP_FOLLOW
;
1447 if (f
& O_DIRECTORY
)
1448 retval
|= LOOKUP_DIRECTORY
;
1454 * p1 and p2 should be directories on the same fs.
1456 struct dentry
*lock_rename(struct dentry
*p1
, struct dentry
*p2
)
1461 mutex_lock_nested(&p1
->d_inode
->i_mutex
, I_MUTEX_PARENT
);
1465 mutex_lock(&p1
->d_inode
->i_sb
->s_vfs_rename_mutex
);
1467 for (p
= p1
; p
->d_parent
!= p
; p
= p
->d_parent
) {
1468 if (p
->d_parent
== p2
) {
1469 mutex_lock_nested(&p2
->d_inode
->i_mutex
, I_MUTEX_PARENT
);
1470 mutex_lock_nested(&p1
->d_inode
->i_mutex
, I_MUTEX_CHILD
);
1475 for (p
= p2
; p
->d_parent
!= p
; p
= p
->d_parent
) {
1476 if (p
->d_parent
== p1
) {
1477 mutex_lock_nested(&p1
->d_inode
->i_mutex
, I_MUTEX_PARENT
);
1478 mutex_lock_nested(&p2
->d_inode
->i_mutex
, I_MUTEX_CHILD
);
1483 mutex_lock_nested(&p1
->d_inode
->i_mutex
, I_MUTEX_PARENT
);
1484 mutex_lock_nested(&p2
->d_inode
->i_mutex
, I_MUTEX_CHILD
);
1488 void unlock_rename(struct dentry
*p1
, struct dentry
*p2
)
1490 mutex_unlock(&p1
->d_inode
->i_mutex
);
1492 mutex_unlock(&p2
->d_inode
->i_mutex
);
1493 mutex_unlock(&p1
->d_inode
->i_sb
->s_vfs_rename_mutex
);
1497 int vfs_create(struct inode
*dir
, struct dentry
*dentry
, int mode
,
1498 struct nameidata
*nd
)
1500 int error
= may_create(dir
, dentry
, nd
);
1505 if (!dir
->i_op
|| !dir
->i_op
->create
)
1506 return -EACCES
; /* shouldn't it be ENOSYS? */
1509 error
= security_inode_create(dir
, dentry
, mode
);
1513 error
= dir
->i_op
->create(dir
, dentry
, mode
, nd
);
1515 fsnotify_create(dir
, dentry
);
1519 int may_open(struct nameidata
*nd
, int acc_mode
, int flag
)
1521 struct dentry
*dentry
= nd
->dentry
;
1522 struct inode
*inode
= dentry
->d_inode
;
1528 if (S_ISLNK(inode
->i_mode
))
1531 if (S_ISDIR(inode
->i_mode
) && (flag
& FMODE_WRITE
))
1534 error
= vfs_permission(nd
, acc_mode
);
1539 * FIFO's, sockets and device files are special: they don't
1540 * actually live on the filesystem itself, and as such you
1541 * can write to them even if the filesystem is read-only.
1543 if (S_ISFIFO(inode
->i_mode
) || S_ISSOCK(inode
->i_mode
)) {
1545 } else if (S_ISBLK(inode
->i_mode
) || S_ISCHR(inode
->i_mode
)) {
1546 if (nd
->mnt
->mnt_flags
& MNT_NODEV
)
1550 } else if (IS_RDONLY(inode
) && (flag
& FMODE_WRITE
))
1553 * An append-only file must be opened in append mode for writing.
1555 if (IS_APPEND(inode
)) {
1556 if ((flag
& FMODE_WRITE
) && !(flag
& O_APPEND
))
1562 /* O_NOATIME can only be set by the owner or superuser */
1563 if (flag
& O_NOATIME
)
1564 if (current
->fsuid
!= inode
->i_uid
&& !capable(CAP_FOWNER
))
1568 * Ensure there are no outstanding leases on the file.
1570 error
= break_lease(inode
, flag
);
1574 if (flag
& O_TRUNC
) {
1575 error
= get_write_access(inode
);
1580 * Refuse to truncate files with mandatory locks held on them.
1582 error
= locks_verify_locked(inode
);
1586 error
= do_truncate(dentry
, 0, ATTR_MTIME
|ATTR_CTIME
, NULL
);
1588 put_write_access(inode
);
1592 if (flag
& FMODE_WRITE
)
1601 * namei for open - this is in fact almost the whole open-routine.
1603 * Note that the low bits of "flag" aren't the same as in the open
1604 * system call - they are 00 - no permissions needed
1605 * 01 - read permission needed
1606 * 10 - write permission needed
1607 * 11 - read/write permissions needed
1608 * which is a lot more logical, and also allows the "no perm" needed
1609 * for symlinks (where the permissions are checked later).
1612 int open_namei(int dfd
, const char *pathname
, int flag
,
1613 int mode
, struct nameidata
*nd
)
1615 int acc_mode
, error
;
1620 acc_mode
= ACC_MODE(flag
);
1622 /* O_TRUNC implies we need access checks for write permissions */
1624 acc_mode
|= MAY_WRITE
;
1626 /* Allow the LSM permission hook to distinguish append
1627 access from general write access. */
1628 if (flag
& O_APPEND
)
1629 acc_mode
|= MAY_APPEND
;
1632 * The simplest case - just a plain lookup.
1634 if (!(flag
& O_CREAT
)) {
1635 error
= path_lookup_open(dfd
, pathname
, lookup_flags(flag
),
1643 * Create - we need to know the parent.
1645 error
= path_lookup_create(dfd
,pathname
,LOOKUP_PARENT
,nd
,flag
,mode
);
1650 * We have the parent and last component. First of all, check
1651 * that we are not asked to creat(2) an obvious directory - that
1655 if (nd
->last_type
!= LAST_NORM
|| nd
->last
.name
[nd
->last
.len
])
1659 nd
->flags
&= ~LOOKUP_PARENT
;
1660 mutex_lock(&dir
->d_inode
->i_mutex
);
1661 path
.dentry
= lookup_hash(nd
);
1665 error
= PTR_ERR(path
.dentry
);
1666 if (IS_ERR(path
.dentry
)) {
1667 mutex_unlock(&dir
->d_inode
->i_mutex
);
1671 if (IS_ERR(nd
->intent
.open
.file
)) {
1672 mutex_unlock(&dir
->d_inode
->i_mutex
);
1673 error
= PTR_ERR(nd
->intent
.open
.file
);
1677 /* Negative dentry, just create the file */
1678 if (!path
.dentry
->d_inode
) {
1679 if (!IS_POSIXACL(dir
->d_inode
))
1680 mode
&= ~current
->fs
->umask
;
1681 error
= vfs_create(dir
->d_inode
, path
.dentry
, mode
, nd
);
1682 mutex_unlock(&dir
->d_inode
->i_mutex
);
1684 nd
->dentry
= path
.dentry
;
1687 /* Don't check for write permission, don't truncate */
1694 * It already exists.
1696 mutex_unlock(&dir
->d_inode
->i_mutex
);
1697 audit_inode_update(path
.dentry
->d_inode
);
1703 if (__follow_mount(&path
)) {
1705 if (flag
& O_NOFOLLOW
)
1710 if (!path
.dentry
->d_inode
)
1712 if (path
.dentry
->d_inode
->i_op
&& path
.dentry
->d_inode
->i_op
->follow_link
)
1715 path_to_nameidata(&path
, nd
);
1717 if (path
.dentry
->d_inode
&& S_ISDIR(path
.dentry
->d_inode
->i_mode
))
1720 error
= may_open(nd
, acc_mode
, flag
);
1726 dput_path(&path
, nd
);
1728 if (!IS_ERR(nd
->intent
.open
.file
))
1729 release_open_intent(nd
);
1735 if (flag
& O_NOFOLLOW
)
1738 * This is subtle. Instead of calling do_follow_link() we do the
1739 * thing by hands. The reason is that this way we have zero link_count
1740 * and path_walk() (called from ->follow_link) honoring LOOKUP_PARENT.
1741 * After that we have the parent and last component, i.e.
1742 * we are in the same situation as after the first path_walk().
1743 * Well, almost - if the last component is normal we get its copy
1744 * stored in nd->last.name and we will have to putname() it when we
1745 * are done. Procfs-like symlinks just set LAST_BIND.
1747 nd
->flags
|= LOOKUP_PARENT
;
1748 error
= security_inode_follow_link(path
.dentry
, nd
);
1751 error
= __do_follow_link(&path
, nd
);
1753 /* Does someone understand code flow here? Or it is only
1754 * me so stupid? Anathema to whoever designed this non-sense
1755 * with "intent.open".
1757 release_open_intent(nd
);
1760 nd
->flags
&= ~LOOKUP_PARENT
;
1761 if (nd
->last_type
== LAST_BIND
)
1764 if (nd
->last_type
!= LAST_NORM
)
1766 if (nd
->last
.name
[nd
->last
.len
]) {
1767 __putname(nd
->last
.name
);
1772 __putname(nd
->last
.name
);
1776 mutex_lock(&dir
->d_inode
->i_mutex
);
1777 path
.dentry
= lookup_hash(nd
);
1779 __putname(nd
->last
.name
);
1784 * lookup_create - lookup a dentry, creating it if it doesn't exist
1785 * @nd: nameidata info
1786 * @is_dir: directory flag
1788 * Simple function to lookup and return a dentry and create it
1789 * if it doesn't exist. Is SMP-safe.
1791 * Returns with nd->dentry->d_inode->i_mutex locked.
1793 struct dentry
*lookup_create(struct nameidata
*nd
, int is_dir
)
1795 struct dentry
*dentry
= ERR_PTR(-EEXIST
);
1797 mutex_lock_nested(&nd
->dentry
->d_inode
->i_mutex
, I_MUTEX_PARENT
);
1799 * Yucky last component or no last component at all?
1800 * (foo/., foo/.., /////)
1802 if (nd
->last_type
!= LAST_NORM
)
1804 nd
->flags
&= ~LOOKUP_PARENT
;
1805 nd
->flags
|= LOOKUP_CREATE
;
1806 nd
->intent
.open
.flags
= O_EXCL
;
1809 * Do the final lookup.
1811 dentry
= lookup_hash(nd
);
1816 * Special case - lookup gave negative, but... we had foo/bar/
1817 * From the vfs_mknod() POV we just have a negative dentry -
1818 * all is fine. Let's be bastards - you had / on the end, you've
1819 * been asking for (non-existent) directory. -ENOENT for you.
1821 if (!is_dir
&& nd
->last
.name
[nd
->last
.len
] && !dentry
->d_inode
)
1826 dentry
= ERR_PTR(-ENOENT
);
1830 EXPORT_SYMBOL_GPL(lookup_create
);
1832 int vfs_mknod(struct inode
*dir
, struct dentry
*dentry
, int mode
, dev_t dev
)
1834 int error
= may_create(dir
, dentry
, NULL
);
1839 if ((S_ISCHR(mode
) || S_ISBLK(mode
)) && !capable(CAP_MKNOD
))
1842 if (!dir
->i_op
|| !dir
->i_op
->mknod
)
1845 error
= security_inode_mknod(dir
, dentry
, mode
, dev
);
1850 error
= dir
->i_op
->mknod(dir
, dentry
, mode
, dev
);
1852 fsnotify_create(dir
, dentry
);
1856 asmlinkage
long sys_mknodat(int dfd
, const char __user
*filename
, int mode
,
1861 struct dentry
* dentry
;
1862 struct nameidata nd
;
1866 tmp
= getname(filename
);
1868 return PTR_ERR(tmp
);
1870 error
= do_path_lookup(dfd
, tmp
, LOOKUP_PARENT
, &nd
);
1873 dentry
= lookup_create(&nd
, 0);
1874 error
= PTR_ERR(dentry
);
1876 if (!IS_POSIXACL(nd
.dentry
->d_inode
))
1877 mode
&= ~current
->fs
->umask
;
1878 if (!IS_ERR(dentry
)) {
1879 switch (mode
& S_IFMT
) {
1880 case 0: case S_IFREG
:
1881 error
= vfs_create(nd
.dentry
->d_inode
,dentry
,mode
,&nd
);
1883 case S_IFCHR
: case S_IFBLK
:
1884 error
= vfs_mknod(nd
.dentry
->d_inode
,dentry
,mode
,
1885 new_decode_dev(dev
));
1887 case S_IFIFO
: case S_IFSOCK
:
1888 error
= vfs_mknod(nd
.dentry
->d_inode
,dentry
,mode
,0);
1898 mutex_unlock(&nd
.dentry
->d_inode
->i_mutex
);
1906 asmlinkage
long sys_mknod(const char __user
*filename
, int mode
, unsigned dev
)
1908 return sys_mknodat(AT_FDCWD
, filename
, mode
, dev
);
1911 int vfs_mkdir(struct inode
*dir
, struct dentry
*dentry
, int mode
)
1913 int error
= may_create(dir
, dentry
, NULL
);
1918 if (!dir
->i_op
|| !dir
->i_op
->mkdir
)
1921 mode
&= (S_IRWXUGO
|S_ISVTX
);
1922 error
= security_inode_mkdir(dir
, dentry
, mode
);
1927 error
= dir
->i_op
->mkdir(dir
, dentry
, mode
);
1929 fsnotify_mkdir(dir
, dentry
);
1933 asmlinkage
long sys_mkdirat(int dfd
, const char __user
*pathname
, int mode
)
1938 tmp
= getname(pathname
);
1939 error
= PTR_ERR(tmp
);
1941 struct dentry
*dentry
;
1942 struct nameidata nd
;
1944 error
= do_path_lookup(dfd
, tmp
, LOOKUP_PARENT
, &nd
);
1947 dentry
= lookup_create(&nd
, 1);
1948 error
= PTR_ERR(dentry
);
1949 if (!IS_ERR(dentry
)) {
1950 if (!IS_POSIXACL(nd
.dentry
->d_inode
))
1951 mode
&= ~current
->fs
->umask
;
1952 error
= vfs_mkdir(nd
.dentry
->d_inode
, dentry
, mode
);
1955 mutex_unlock(&nd
.dentry
->d_inode
->i_mutex
);
1964 asmlinkage
long sys_mkdir(const char __user
*pathname
, int mode
)
1966 return sys_mkdirat(AT_FDCWD
, pathname
, mode
);
1970 * We try to drop the dentry early: we should have
1971 * a usage count of 2 if we're the only user of this
1972 * dentry, and if that is true (possibly after pruning
1973 * the dcache), then we drop the dentry now.
1975 * A low-level filesystem can, if it choses, legally
1978 * if (!d_unhashed(dentry))
1981 * if it cannot handle the case of removing a directory
1982 * that is still in use by something else..
1984 void dentry_unhash(struct dentry
*dentry
)
1987 if (atomic_read(&dentry
->d_count
))
1988 shrink_dcache_parent(dentry
);
1989 spin_lock(&dcache_lock
);
1990 spin_lock(&dentry
->d_lock
);
1991 if (atomic_read(&dentry
->d_count
) == 2)
1993 spin_unlock(&dentry
->d_lock
);
1994 spin_unlock(&dcache_lock
);
1997 int vfs_rmdir(struct inode
*dir
, struct dentry
*dentry
)
1999 int error
= may_delete(dir
, dentry
, 1);
2004 if (!dir
->i_op
|| !dir
->i_op
->rmdir
)
2009 mutex_lock(&dentry
->d_inode
->i_mutex
);
2010 dentry_unhash(dentry
);
2011 if (d_mountpoint(dentry
))
2014 error
= security_inode_rmdir(dir
, dentry
);
2016 error
= dir
->i_op
->rmdir(dir
, dentry
);
2018 dentry
->d_inode
->i_flags
|= S_DEAD
;
2021 mutex_unlock(&dentry
->d_inode
->i_mutex
);
2030 static long do_rmdir(int dfd
, const char __user
*pathname
)
2034 struct dentry
*dentry
;
2035 struct nameidata nd
;
2037 name
= getname(pathname
);
2039 return PTR_ERR(name
);
2041 error
= do_path_lookup(dfd
, name
, LOOKUP_PARENT
, &nd
);
2045 switch(nd
.last_type
) {
2056 mutex_lock_nested(&nd
.dentry
->d_inode
->i_mutex
, I_MUTEX_PARENT
);
2057 dentry
= lookup_hash(&nd
);
2058 error
= PTR_ERR(dentry
);
2059 if (!IS_ERR(dentry
)) {
2060 error
= vfs_rmdir(nd
.dentry
->d_inode
, dentry
);
2063 mutex_unlock(&nd
.dentry
->d_inode
->i_mutex
);
2071 asmlinkage
long sys_rmdir(const char __user
*pathname
)
2073 return do_rmdir(AT_FDCWD
, pathname
);
2076 int vfs_unlink(struct inode
*dir
, struct dentry
*dentry
)
2078 int error
= may_delete(dir
, dentry
, 0);
2083 if (!dir
->i_op
|| !dir
->i_op
->unlink
)
2088 mutex_lock(&dentry
->d_inode
->i_mutex
);
2089 if (d_mountpoint(dentry
))
2092 error
= security_inode_unlink(dir
, dentry
);
2094 error
= dir
->i_op
->unlink(dir
, dentry
);
2096 mutex_unlock(&dentry
->d_inode
->i_mutex
);
2098 /* We don't d_delete() NFS sillyrenamed files--they still exist. */
2099 if (!error
&& !(dentry
->d_flags
& DCACHE_NFSFS_RENAMED
)) {
2107 * Make sure that the actual truncation of the file will occur outside its
2108 * directory's i_mutex. Truncate can take a long time if there is a lot of
2109 * writeout happening, and we don't want to prevent access to the directory
2110 * while waiting on the I/O.
2112 static long do_unlinkat(int dfd
, const char __user
*pathname
)
2116 struct dentry
*dentry
;
2117 struct nameidata nd
;
2118 struct inode
*inode
= NULL
;
2120 name
= getname(pathname
);
2122 return PTR_ERR(name
);
2124 error
= do_path_lookup(dfd
, name
, LOOKUP_PARENT
, &nd
);
2128 if (nd
.last_type
!= LAST_NORM
)
2130 mutex_lock_nested(&nd
.dentry
->d_inode
->i_mutex
, I_MUTEX_PARENT
);
2131 dentry
= lookup_hash(&nd
);
2132 error
= PTR_ERR(dentry
);
2133 if (!IS_ERR(dentry
)) {
2134 /* Why not before? Because we want correct error value */
2135 if (nd
.last
.name
[nd
.last
.len
])
2137 inode
= dentry
->d_inode
;
2139 atomic_inc(&inode
->i_count
);
2140 error
= vfs_unlink(nd
.dentry
->d_inode
, dentry
);
2144 mutex_unlock(&nd
.dentry
->d_inode
->i_mutex
);
2146 iput(inode
); /* truncate the inode here */
2154 error
= !dentry
->d_inode
? -ENOENT
:
2155 S_ISDIR(dentry
->d_inode
->i_mode
) ? -EISDIR
: -ENOTDIR
;
2159 asmlinkage
long sys_unlinkat(int dfd
, const char __user
*pathname
, int flag
)
2161 if ((flag
& ~AT_REMOVEDIR
) != 0)
2164 if (flag
& AT_REMOVEDIR
)
2165 return do_rmdir(dfd
, pathname
);
2167 return do_unlinkat(dfd
, pathname
);
2170 asmlinkage
long sys_unlink(const char __user
*pathname
)
2172 return do_unlinkat(AT_FDCWD
, pathname
);
2175 int vfs_symlink(struct inode
*dir
, struct dentry
*dentry
, const char *oldname
, int mode
)
2177 int error
= may_create(dir
, dentry
, NULL
);
2182 if (!dir
->i_op
|| !dir
->i_op
->symlink
)
2185 error
= security_inode_symlink(dir
, dentry
, oldname
);
2190 error
= dir
->i_op
->symlink(dir
, dentry
, oldname
);
2192 fsnotify_create(dir
, dentry
);
2196 asmlinkage
long sys_symlinkat(const char __user
*oldname
,
2197 int newdfd
, const char __user
*newname
)
2203 from
= getname(oldname
);
2205 return PTR_ERR(from
);
2206 to
= getname(newname
);
2207 error
= PTR_ERR(to
);
2209 struct dentry
*dentry
;
2210 struct nameidata nd
;
2212 error
= do_path_lookup(newdfd
, to
, LOOKUP_PARENT
, &nd
);
2215 dentry
= lookup_create(&nd
, 0);
2216 error
= PTR_ERR(dentry
);
2217 if (!IS_ERR(dentry
)) {
2218 error
= vfs_symlink(nd
.dentry
->d_inode
, dentry
, from
, S_IALLUGO
);
2221 mutex_unlock(&nd
.dentry
->d_inode
->i_mutex
);
2230 asmlinkage
long sys_symlink(const char __user
*oldname
, const char __user
*newname
)
2232 return sys_symlinkat(oldname
, AT_FDCWD
, newname
);
2235 int vfs_link(struct dentry
*old_dentry
, struct inode
*dir
, struct dentry
*new_dentry
)
2237 struct inode
*inode
= old_dentry
->d_inode
;
2243 error
= may_create(dir
, new_dentry
, NULL
);
2247 if (dir
->i_sb
!= inode
->i_sb
)
2251 * A link to an append-only or immutable file cannot be created.
2253 if (IS_APPEND(inode
) || IS_IMMUTABLE(inode
))
2255 if (!dir
->i_op
|| !dir
->i_op
->link
)
2257 if (S_ISDIR(old_dentry
->d_inode
->i_mode
))
2260 error
= security_inode_link(old_dentry
, dir
, new_dentry
);
2264 mutex_lock(&old_dentry
->d_inode
->i_mutex
);
2266 error
= dir
->i_op
->link(old_dentry
, dir
, new_dentry
);
2267 mutex_unlock(&old_dentry
->d_inode
->i_mutex
);
2269 fsnotify_create(dir
, new_dentry
);
2274 * Hardlinks are often used in delicate situations. We avoid
2275 * security-related surprises by not following symlinks on the
2278 * We don't follow them on the oldname either to be compatible
2279 * with linux 2.0, and to avoid hard-linking to directories
2280 * and other special files. --ADM
2282 asmlinkage
long sys_linkat(int olddfd
, const char __user
*oldname
,
2283 int newdfd
, const char __user
*newname
,
2286 struct dentry
*new_dentry
;
2287 struct nameidata nd
, old_nd
;
2291 if ((flags
& ~AT_SYMLINK_FOLLOW
) != 0)
2294 to
= getname(newname
);
2298 error
= __user_walk_fd(olddfd
, oldname
,
2299 flags
& AT_SYMLINK_FOLLOW
? LOOKUP_FOLLOW
: 0,
2303 error
= do_path_lookup(newdfd
, to
, LOOKUP_PARENT
, &nd
);
2307 if (old_nd
.mnt
!= nd
.mnt
)
2309 new_dentry
= lookup_create(&nd
, 0);
2310 error
= PTR_ERR(new_dentry
);
2311 if (!IS_ERR(new_dentry
)) {
2312 error
= vfs_link(old_nd
.dentry
, nd
.dentry
->d_inode
, new_dentry
);
2315 mutex_unlock(&nd
.dentry
->d_inode
->i_mutex
);
2319 path_release(&old_nd
);
2326 asmlinkage
long sys_link(const char __user
*oldname
, const char __user
*newname
)
2328 return sys_linkat(AT_FDCWD
, oldname
, AT_FDCWD
, newname
, 0);
2332 * The worst of all namespace operations - renaming directory. "Perverted"
2333 * doesn't even start to describe it. Somebody in UCB had a heck of a trip...
2335 * a) we can get into loop creation. Check is done in is_subdir().
2336 * b) race potential - two innocent renames can create a loop together.
2337 * That's where 4.4 screws up. Current fix: serialization on
2338 * sb->s_vfs_rename_mutex. We might be more accurate, but that's another
2340 * c) we have to lock _three_ objects - parents and victim (if it exists).
2341 * And that - after we got ->i_mutex on parents (until then we don't know
2342 * whether the target exists). Solution: try to be smart with locking
2343 * order for inodes. We rely on the fact that tree topology may change
2344 * only under ->s_vfs_rename_mutex _and_ that parent of the object we
2345 * move will be locked. Thus we can rank directories by the tree
2346 * (ancestors first) and rank all non-directories after them.
2347 * That works since everybody except rename does "lock parent, lookup,
2348 * lock child" and rename is under ->s_vfs_rename_mutex.
2349 * HOWEVER, it relies on the assumption that any object with ->lookup()
2350 * has no more than 1 dentry. If "hybrid" objects will ever appear,
2351 * we'd better make sure that there's no link(2) for them.
2352 * d) some filesystems don't support opened-but-unlinked directories,
2353 * either because of layout or because they are not ready to deal with
2354 * all cases correctly. The latter will be fixed (taking this sort of
2355 * stuff into VFS), but the former is not going away. Solution: the same
2356 * trick as in rmdir().
2357 * e) conversion from fhandle to dentry may come in the wrong moment - when
2358 * we are removing the target. Solution: we will have to grab ->i_mutex
2359 * in the fhandle_to_dentry code. [FIXME - current nfsfh.c relies on
2360 * ->i_mutex on parents, which works but leads to some truely excessive
2363 static int vfs_rename_dir(struct inode
*old_dir
, struct dentry
*old_dentry
,
2364 struct inode
*new_dir
, struct dentry
*new_dentry
)
2367 struct inode
*target
;
2370 * If we are going to change the parent - check write permissions,
2371 * we'll need to flip '..'.
2373 if (new_dir
!= old_dir
) {
2374 error
= permission(old_dentry
->d_inode
, MAY_WRITE
, NULL
);
2379 error
= security_inode_rename(old_dir
, old_dentry
, new_dir
, new_dentry
);
2383 target
= new_dentry
->d_inode
;
2385 mutex_lock(&target
->i_mutex
);
2386 dentry_unhash(new_dentry
);
2388 if (d_mountpoint(old_dentry
)||d_mountpoint(new_dentry
))
2391 error
= old_dir
->i_op
->rename(old_dir
, old_dentry
, new_dir
, new_dentry
);
2394 target
->i_flags
|= S_DEAD
;
2395 mutex_unlock(&target
->i_mutex
);
2396 if (d_unhashed(new_dentry
))
2397 d_rehash(new_dentry
);
2401 if (!(old_dir
->i_sb
->s_type
->fs_flags
& FS_RENAME_DOES_D_MOVE
))
2402 d_move(old_dentry
,new_dentry
);
2406 static int vfs_rename_other(struct inode
*old_dir
, struct dentry
*old_dentry
,
2407 struct inode
*new_dir
, struct dentry
*new_dentry
)
2409 struct inode
*target
;
2412 error
= security_inode_rename(old_dir
, old_dentry
, new_dir
, new_dentry
);
2417 target
= new_dentry
->d_inode
;
2419 mutex_lock(&target
->i_mutex
);
2420 if (d_mountpoint(old_dentry
)||d_mountpoint(new_dentry
))
2423 error
= old_dir
->i_op
->rename(old_dir
, old_dentry
, new_dir
, new_dentry
);
2425 if (!(old_dir
->i_sb
->s_type
->fs_flags
& FS_RENAME_DOES_D_MOVE
))
2426 d_move(old_dentry
, new_dentry
);
2429 mutex_unlock(&target
->i_mutex
);
2434 int vfs_rename(struct inode
*old_dir
, struct dentry
*old_dentry
,
2435 struct inode
*new_dir
, struct dentry
*new_dentry
)
2438 int is_dir
= S_ISDIR(old_dentry
->d_inode
->i_mode
);
2439 const char *old_name
;
2441 if (old_dentry
->d_inode
== new_dentry
->d_inode
)
2444 error
= may_delete(old_dir
, old_dentry
, is_dir
);
2448 if (!new_dentry
->d_inode
)
2449 error
= may_create(new_dir
, new_dentry
, NULL
);
2451 error
= may_delete(new_dir
, new_dentry
, is_dir
);
2455 if (!old_dir
->i_op
|| !old_dir
->i_op
->rename
)
2458 DQUOT_INIT(old_dir
);
2459 DQUOT_INIT(new_dir
);
2461 old_name
= fsnotify_oldname_init(old_dentry
->d_name
.name
);
2464 error
= vfs_rename_dir(old_dir
,old_dentry
,new_dir
,new_dentry
);
2466 error
= vfs_rename_other(old_dir
,old_dentry
,new_dir
,new_dentry
);
2468 const char *new_name
= old_dentry
->d_name
.name
;
2469 fsnotify_move(old_dir
, new_dir
, old_name
, new_name
, is_dir
,
2470 new_dentry
->d_inode
, old_dentry
->d_inode
);
2472 fsnotify_oldname_free(old_name
);
2477 static int do_rename(int olddfd
, const char *oldname
,
2478 int newdfd
, const char *newname
)
2481 struct dentry
* old_dir
, * new_dir
;
2482 struct dentry
* old_dentry
, *new_dentry
;
2483 struct dentry
* trap
;
2484 struct nameidata oldnd
, newnd
;
2486 error
= do_path_lookup(olddfd
, oldname
, LOOKUP_PARENT
, &oldnd
);
2490 error
= do_path_lookup(newdfd
, newname
, LOOKUP_PARENT
, &newnd
);
2495 if (oldnd
.mnt
!= newnd
.mnt
)
2498 old_dir
= oldnd
.dentry
;
2500 if (oldnd
.last_type
!= LAST_NORM
)
2503 new_dir
= newnd
.dentry
;
2504 if (newnd
.last_type
!= LAST_NORM
)
2507 trap
= lock_rename(new_dir
, old_dir
);
2509 old_dentry
= lookup_hash(&oldnd
);
2510 error
= PTR_ERR(old_dentry
);
2511 if (IS_ERR(old_dentry
))
2513 /* source must exist */
2515 if (!old_dentry
->d_inode
)
2517 /* unless the source is a directory trailing slashes give -ENOTDIR */
2518 if (!S_ISDIR(old_dentry
->d_inode
->i_mode
)) {
2520 if (oldnd
.last
.name
[oldnd
.last
.len
])
2522 if (newnd
.last
.name
[newnd
.last
.len
])
2525 /* source should not be ancestor of target */
2527 if (old_dentry
== trap
)
2529 new_dentry
= lookup_hash(&newnd
);
2530 error
= PTR_ERR(new_dentry
);
2531 if (IS_ERR(new_dentry
))
2533 /* target should not be an ancestor of source */
2535 if (new_dentry
== trap
)
2538 error
= vfs_rename(old_dir
->d_inode
, old_dentry
,
2539 new_dir
->d_inode
, new_dentry
);
2545 unlock_rename(new_dir
, old_dir
);
2547 path_release(&newnd
);
2549 path_release(&oldnd
);
2554 asmlinkage
long sys_renameat(int olddfd
, const char __user
*oldname
,
2555 int newdfd
, const char __user
*newname
)
2561 from
= getname(oldname
);
2563 return PTR_ERR(from
);
2564 to
= getname(newname
);
2565 error
= PTR_ERR(to
);
2567 error
= do_rename(olddfd
, from
, newdfd
, to
);
2574 asmlinkage
long sys_rename(const char __user
*oldname
, const char __user
*newname
)
2576 return sys_renameat(AT_FDCWD
, oldname
, AT_FDCWD
, newname
);
2579 int vfs_readlink(struct dentry
*dentry
, char __user
*buffer
, int buflen
, const char *link
)
2583 len
= PTR_ERR(link
);
2588 if (len
> (unsigned) buflen
)
2590 if (copy_to_user(buffer
, link
, len
))
2597 * A helper for ->readlink(). This should be used *ONLY* for symlinks that
2598 * have ->follow_link() touching nd only in nd_set_link(). Using (or not
2599 * using) it for any given inode is up to filesystem.
2601 int generic_readlink(struct dentry
*dentry
, char __user
*buffer
, int buflen
)
2603 struct nameidata nd
;
2607 cookie
= dentry
->d_inode
->i_op
->follow_link(dentry
, &nd
);
2608 if (!IS_ERR(cookie
)) {
2609 int res
= vfs_readlink(dentry
, buffer
, buflen
, nd_get_link(&nd
));
2610 if (dentry
->d_inode
->i_op
->put_link
)
2611 dentry
->d_inode
->i_op
->put_link(dentry
, &nd
, cookie
);
2612 cookie
= ERR_PTR(res
);
2614 return PTR_ERR(cookie
);
2617 int vfs_follow_link(struct nameidata
*nd
, const char *link
)
2619 return __vfs_follow_link(nd
, link
);
2622 /* get the link contents into pagecache */
2623 static char *page_getlink(struct dentry
* dentry
, struct page
**ppage
)
2626 struct address_space
*mapping
= dentry
->d_inode
->i_mapping
;
2627 page
= read_mapping_page(mapping
, 0, NULL
);
2630 wait_on_page_locked(page
);
2631 if (!PageUptodate(page
))
2637 page_cache_release(page
);
2638 return ERR_PTR(-EIO
);
2644 int page_readlink(struct dentry
*dentry
, char __user
*buffer
, int buflen
)
2646 struct page
*page
= NULL
;
2647 char *s
= page_getlink(dentry
, &page
);
2648 int res
= vfs_readlink(dentry
,buffer
,buflen
,s
);
2651 page_cache_release(page
);
2656 void *page_follow_link_light(struct dentry
*dentry
, struct nameidata
*nd
)
2658 struct page
*page
= NULL
;
2659 nd_set_link(nd
, page_getlink(dentry
, &page
));
2663 void page_put_link(struct dentry
*dentry
, struct nameidata
*nd
, void *cookie
)
2665 struct page
*page
= cookie
;
2669 page_cache_release(page
);
2673 int __page_symlink(struct inode
*inode
, const char *symname
, int len
,
2676 struct address_space
*mapping
= inode
->i_mapping
;
2682 page
= find_or_create_page(mapping
, 0, gfp_mask
);
2685 err
= mapping
->a_ops
->prepare_write(NULL
, page
, 0, len
-1);
2686 if (err
== AOP_TRUNCATED_PAGE
) {
2687 page_cache_release(page
);
2692 kaddr
= kmap_atomic(page
, KM_USER0
);
2693 memcpy(kaddr
, symname
, len
-1);
2694 kunmap_atomic(kaddr
, KM_USER0
);
2695 err
= mapping
->a_ops
->commit_write(NULL
, page
, 0, len
-1);
2696 if (err
== AOP_TRUNCATED_PAGE
) {
2697 page_cache_release(page
);
2703 * Notice that we are _not_ going to block here - end of page is
2704 * unmapped, so this will only try to map the rest of page, see
2705 * that it is unmapped (typically even will not look into inode -
2706 * ->i_size will be enough for everything) and zero it out.
2707 * OTOH it's obviously correct and should make the page up-to-date.
2709 if (!PageUptodate(page
)) {
2710 err
= mapping
->a_ops
->readpage(NULL
, page
);
2711 if (err
!= AOP_TRUNCATED_PAGE
)
2712 wait_on_page_locked(page
);
2716 page_cache_release(page
);
2719 mark_inode_dirty(inode
);
2723 page_cache_release(page
);
2728 int page_symlink(struct inode
*inode
, const char *symname
, int len
)
2730 return __page_symlink(inode
, symname
, len
,
2731 mapping_gfp_mask(inode
->i_mapping
));
2734 struct inode_operations page_symlink_inode_operations
= {
2735 .readlink
= generic_readlink
,
2736 .follow_link
= page_follow_link_light
,
2737 .put_link
= page_put_link
,
2740 EXPORT_SYMBOL(__user_walk
);
2741 EXPORT_SYMBOL(__user_walk_fd
);
2742 EXPORT_SYMBOL(follow_down
);
2743 EXPORT_SYMBOL(follow_up
);
2744 EXPORT_SYMBOL(get_write_access
); /* binfmt_aout */
2745 EXPORT_SYMBOL(getname
);
2746 EXPORT_SYMBOL(lock_rename
);
2747 EXPORT_SYMBOL(lookup_one_len
);
2748 EXPORT_SYMBOL(page_follow_link_light
);
2749 EXPORT_SYMBOL(page_put_link
);
2750 EXPORT_SYMBOL(page_readlink
);
2751 EXPORT_SYMBOL(__page_symlink
);
2752 EXPORT_SYMBOL(page_symlink
);
2753 EXPORT_SYMBOL(page_symlink_inode_operations
);
2754 EXPORT_SYMBOL(path_lookup
);
2755 EXPORT_SYMBOL(path_release
);
2756 EXPORT_SYMBOL(path_walk
);
2757 EXPORT_SYMBOL(permission
);
2758 EXPORT_SYMBOL(vfs_permission
);
2759 EXPORT_SYMBOL(file_permission
);
2760 EXPORT_SYMBOL(unlock_rename
);
2761 EXPORT_SYMBOL(vfs_create
);
2762 EXPORT_SYMBOL(vfs_follow_link
);
2763 EXPORT_SYMBOL(vfs_link
);
2764 EXPORT_SYMBOL(vfs_mkdir
);
2765 EXPORT_SYMBOL(vfs_mknod
);
2766 EXPORT_SYMBOL(generic_permission
);
2767 EXPORT_SYMBOL(vfs_readlink
);
2768 EXPORT_SYMBOL(vfs_rename
);
2769 EXPORT_SYMBOL(vfs_rmdir
);
2770 EXPORT_SYMBOL(vfs_symlink
);
2771 EXPORT_SYMBOL(vfs_unlink
);
2772 EXPORT_SYMBOL(dentry_unhash
);
2773 EXPORT_SYMBOL(generic_readlink
);