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 or
253 * the fs is mounted with the "noexec" flag.
255 if ((mask
& MAY_EXEC
) && S_ISREG(mode
) && (!(mode
& S_IXUGO
) ||
256 (nd
&& nd
->mnt
&& (nd
->mnt
->mnt_flags
& MNT_NOEXEC
))))
259 /* Ordinary permission routines do not understand MAY_APPEND. */
260 submask
= mask
& ~MAY_APPEND
;
261 if (inode
->i_op
&& inode
->i_op
->permission
)
262 retval
= inode
->i_op
->permission(inode
, submask
, nd
);
264 retval
= generic_permission(inode
, submask
, NULL
);
268 return security_inode_permission(inode
, mask
, nd
);
272 * vfs_permission - check for access rights to a given path
273 * @nd: lookup result that describes the path
274 * @mask: right to check for (%MAY_READ, %MAY_WRITE, %MAY_EXEC)
276 * Used to check for read/write/execute permissions on a path.
277 * We use "fsuid" for this, letting us set arbitrary permissions
278 * for filesystem access without changing the "normal" uids which
279 * are used for other things.
281 int vfs_permission(struct nameidata
*nd
, int mask
)
283 return permission(nd
->dentry
->d_inode
, mask
, nd
);
287 * file_permission - check for additional access rights to a given file
288 * @file: file to check access rights for
289 * @mask: right to check for (%MAY_READ, %MAY_WRITE, %MAY_EXEC)
291 * Used to check for read/write/execute permissions on an already opened
295 * Do not use this function in new code. All access checks should
296 * be done using vfs_permission().
298 int file_permission(struct file
*file
, int mask
)
300 return permission(file
->f_dentry
->d_inode
, mask
, NULL
);
304 * get_write_access() gets write permission for a file.
305 * put_write_access() releases this write permission.
306 * This is used for regular files.
307 * We cannot support write (and maybe mmap read-write shared) accesses and
308 * MAP_DENYWRITE mmappings simultaneously. The i_writecount field of an inode
309 * can have the following values:
310 * 0: no writers, no VM_DENYWRITE mappings
311 * < 0: (-i_writecount) vm_area_structs with VM_DENYWRITE set exist
312 * > 0: (i_writecount) users are writing to the file.
314 * Normally we operate on that counter with atomic_{inc,dec} and it's safe
315 * except for the cases where we don't hold i_writecount yet. Then we need to
316 * use {get,deny}_write_access() - these functions check the sign and refuse
317 * to do the change if sign is wrong. Exclusion between them is provided by
318 * the inode->i_lock spinlock.
321 int get_write_access(struct inode
* inode
)
323 spin_lock(&inode
->i_lock
);
324 if (atomic_read(&inode
->i_writecount
) < 0) {
325 spin_unlock(&inode
->i_lock
);
328 atomic_inc(&inode
->i_writecount
);
329 spin_unlock(&inode
->i_lock
);
334 int deny_write_access(struct file
* file
)
336 struct inode
*inode
= file
->f_dentry
->d_inode
;
338 spin_lock(&inode
->i_lock
);
339 if (atomic_read(&inode
->i_writecount
) > 0) {
340 spin_unlock(&inode
->i_lock
);
343 atomic_dec(&inode
->i_writecount
);
344 spin_unlock(&inode
->i_lock
);
349 void path_release(struct nameidata
*nd
)
356 * umount() mustn't call path_release()/mntput() as that would clear
359 void path_release_on_umount(struct nameidata
*nd
)
362 mntput_no_expire(nd
->mnt
);
366 * release_open_intent - free up open intent resources
367 * @nd: pointer to nameidata
369 void release_open_intent(struct nameidata
*nd
)
371 if (nd
->intent
.open
.file
->f_dentry
== NULL
)
372 put_filp(nd
->intent
.open
.file
);
374 fput(nd
->intent
.open
.file
);
377 static inline struct dentry
*
378 do_revalidate(struct dentry
*dentry
, struct nameidata
*nd
)
380 int status
= dentry
->d_op
->d_revalidate(dentry
, nd
);
381 if (unlikely(status
<= 0)) {
383 * The dentry failed validation.
384 * If d_revalidate returned 0 attempt to invalidate
385 * the dentry otherwise d_revalidate is asking us
386 * to return a fail status.
389 if (!d_invalidate(dentry
)) {
395 dentry
= ERR_PTR(status
);
402 * Internal lookup() using the new generic dcache.
405 static struct dentry
* cached_lookup(struct dentry
* parent
, struct qstr
* name
, struct nameidata
*nd
)
407 struct dentry
* dentry
= __d_lookup(parent
, name
);
409 /* lockess __d_lookup may fail due to concurrent d_move()
410 * in some unrelated directory, so try with d_lookup
413 dentry
= d_lookup(parent
, name
);
415 if (dentry
&& dentry
->d_op
&& dentry
->d_op
->d_revalidate
)
416 dentry
= do_revalidate(dentry
, nd
);
422 * Short-cut version of permission(), for calling by
423 * path_walk(), when dcache lock is held. Combines parts
424 * of permission() and generic_permission(), and tests ONLY for
425 * MAY_EXEC permission.
427 * If appropriate, check DAC only. If not appropriate, or
428 * short-cut DAC fails, then call permission() to do more
429 * complete permission check.
431 static int exec_permission_lite(struct inode
*inode
,
432 struct nameidata
*nd
)
434 umode_t mode
= inode
->i_mode
;
436 if (inode
->i_op
&& inode
->i_op
->permission
)
439 if (current
->fsuid
== inode
->i_uid
)
441 else if (in_group_p(inode
->i_gid
))
447 if ((inode
->i_mode
& S_IXUGO
) && capable(CAP_DAC_OVERRIDE
))
450 if (S_ISDIR(inode
->i_mode
) && capable(CAP_DAC_OVERRIDE
))
453 if (S_ISDIR(inode
->i_mode
) && capable(CAP_DAC_READ_SEARCH
))
458 return security_inode_permission(inode
, MAY_EXEC
, nd
);
462 * This is called when everything else fails, and we actually have
463 * to go to the low-level filesystem to find out what we should do..
465 * We get the directory semaphore, and after getting that we also
466 * make sure that nobody added the entry to the dcache in the meantime..
469 static struct dentry
* real_lookup(struct dentry
* parent
, struct qstr
* name
, struct nameidata
*nd
)
471 struct dentry
* result
;
472 struct inode
*dir
= parent
->d_inode
;
474 mutex_lock(&dir
->i_mutex
);
476 * First re-do the cached lookup just in case it was created
477 * while we waited for the directory semaphore..
479 * FIXME! This could use version numbering or similar to
480 * avoid unnecessary cache lookups.
482 * The "dcache_lock" is purely to protect the RCU list walker
483 * from concurrent renames at this point (we mustn't get false
484 * negatives from the RCU list walk here, unlike the optimistic
487 * so doing d_lookup() (with seqlock), instead of lockfree __d_lookup
489 result
= d_lookup(parent
, name
);
491 struct dentry
* dentry
= d_alloc(parent
, name
);
492 result
= ERR_PTR(-ENOMEM
);
494 result
= dir
->i_op
->lookup(dir
, dentry
, nd
);
500 mutex_unlock(&dir
->i_mutex
);
505 * Uhhuh! Nasty case: the cache was re-populated while
506 * we waited on the semaphore. Need to revalidate.
508 mutex_unlock(&dir
->i_mutex
);
509 if (result
->d_op
&& result
->d_op
->d_revalidate
) {
510 result
= do_revalidate(result
, nd
);
512 result
= ERR_PTR(-ENOENT
);
517 static int __emul_lookup_dentry(const char *, struct nameidata
*);
520 static __always_inline
int
521 walk_init_root(const char *name
, struct nameidata
*nd
)
523 struct fs_struct
*fs
= current
->fs
;
525 read_lock(&fs
->lock
);
526 if (fs
->altroot
&& !(nd
->flags
& LOOKUP_NOALT
)) {
527 nd
->mnt
= mntget(fs
->altrootmnt
);
528 nd
->dentry
= dget(fs
->altroot
);
529 read_unlock(&fs
->lock
);
530 if (__emul_lookup_dentry(name
,nd
))
532 read_lock(&fs
->lock
);
534 nd
->mnt
= mntget(fs
->rootmnt
);
535 nd
->dentry
= dget(fs
->root
);
536 read_unlock(&fs
->lock
);
540 static __always_inline
int __vfs_follow_link(struct nameidata
*nd
, const char *link
)
549 if (!walk_init_root(link
, nd
))
550 /* weird __emul_prefix() stuff did it */
553 res
= link_path_walk(link
, nd
);
555 if (nd
->depth
|| res
|| nd
->last_type
!=LAST_NORM
)
558 * If it is an iterative symlinks resolution in open_namei() we
559 * have to copy the last component. And all that crap because of
560 * bloody create() on broken symlinks. Furrfu...
563 if (unlikely(!name
)) {
567 strcpy(name
, nd
->last
.name
);
568 nd
->last
.name
= name
;
572 return PTR_ERR(link
);
576 struct vfsmount
*mnt
;
577 struct dentry
*dentry
;
580 static inline void dput_path(struct path
*path
, struct nameidata
*nd
)
583 if (path
->mnt
!= nd
->mnt
)
587 static inline void path_to_nameidata(struct path
*path
, struct nameidata
*nd
)
590 if (nd
->mnt
!= path
->mnt
)
593 nd
->dentry
= path
->dentry
;
596 static __always_inline
int __do_follow_link(struct path
*path
, struct nameidata
*nd
)
600 struct dentry
*dentry
= path
->dentry
;
602 touch_atime(path
->mnt
, dentry
);
603 nd_set_link(nd
, NULL
);
605 if (path
->mnt
!= nd
->mnt
) {
606 path_to_nameidata(path
, nd
);
610 cookie
= dentry
->d_inode
->i_op
->follow_link(dentry
, nd
);
611 error
= PTR_ERR(cookie
);
612 if (!IS_ERR(cookie
)) {
613 char *s
= nd_get_link(nd
);
616 error
= __vfs_follow_link(nd
, s
);
617 if (dentry
->d_inode
->i_op
->put_link
)
618 dentry
->d_inode
->i_op
->put_link(dentry
, nd
, cookie
);
627 * This limits recursive symlink follows to 8, while
628 * limiting consecutive symlinks to 40.
630 * Without that kind of total limit, nasty chains of consecutive
631 * symlinks can cause almost arbitrarily long lookups.
633 static inline int do_follow_link(struct path
*path
, struct nameidata
*nd
)
636 if (current
->link_count
>= MAX_NESTED_LINKS
)
638 if (current
->total_link_count
>= 40)
640 BUG_ON(nd
->depth
>= MAX_NESTED_LINKS
);
642 err
= security_inode_follow_link(path
->dentry
, nd
);
645 current
->link_count
++;
646 current
->total_link_count
++;
648 err
= __do_follow_link(path
, nd
);
649 current
->link_count
--;
658 int follow_up(struct vfsmount
**mnt
, struct dentry
**dentry
)
660 struct vfsmount
*parent
;
661 struct dentry
*mountpoint
;
662 spin_lock(&vfsmount_lock
);
663 parent
=(*mnt
)->mnt_parent
;
664 if (parent
== *mnt
) {
665 spin_unlock(&vfsmount_lock
);
669 mountpoint
=dget((*mnt
)->mnt_mountpoint
);
670 spin_unlock(&vfsmount_lock
);
672 *dentry
= mountpoint
;
678 /* no need for dcache_lock, as serialization is taken care in
681 static int __follow_mount(struct path
*path
)
684 while (d_mountpoint(path
->dentry
)) {
685 struct vfsmount
*mounted
= lookup_mnt(path
->mnt
, path
->dentry
);
692 path
->dentry
= dget(mounted
->mnt_root
);
698 static void follow_mount(struct vfsmount
**mnt
, struct dentry
**dentry
)
700 while (d_mountpoint(*dentry
)) {
701 struct vfsmount
*mounted
= lookup_mnt(*mnt
, *dentry
);
707 *dentry
= dget(mounted
->mnt_root
);
711 /* no need for dcache_lock, as serialization is taken care in
714 int follow_down(struct vfsmount
**mnt
, struct dentry
**dentry
)
716 struct vfsmount
*mounted
;
718 mounted
= lookup_mnt(*mnt
, *dentry
);
723 *dentry
= dget(mounted
->mnt_root
);
729 static __always_inline
void follow_dotdot(struct nameidata
*nd
)
731 struct fs_struct
*fs
= current
->fs
;
734 struct vfsmount
*parent
;
735 struct dentry
*old
= nd
->dentry
;
737 read_lock(&fs
->lock
);
738 if (nd
->dentry
== fs
->root
&&
739 nd
->mnt
== fs
->rootmnt
) {
740 read_unlock(&fs
->lock
);
743 read_unlock(&fs
->lock
);
744 spin_lock(&dcache_lock
);
745 if (nd
->dentry
!= nd
->mnt
->mnt_root
) {
746 nd
->dentry
= dget(nd
->dentry
->d_parent
);
747 spin_unlock(&dcache_lock
);
751 spin_unlock(&dcache_lock
);
752 spin_lock(&vfsmount_lock
);
753 parent
= nd
->mnt
->mnt_parent
;
754 if (parent
== nd
->mnt
) {
755 spin_unlock(&vfsmount_lock
);
759 nd
->dentry
= dget(nd
->mnt
->mnt_mountpoint
);
760 spin_unlock(&vfsmount_lock
);
765 follow_mount(&nd
->mnt
, &nd
->dentry
);
769 * It's more convoluted than I'd like it to be, but... it's still fairly
770 * small and for now I'd prefer to have fast path as straight as possible.
771 * It _is_ time-critical.
773 static int do_lookup(struct nameidata
*nd
, struct qstr
*name
,
776 struct vfsmount
*mnt
= nd
->mnt
;
777 struct dentry
*dentry
= __d_lookup(nd
->dentry
, name
);
781 if (dentry
->d_op
&& dentry
->d_op
->d_revalidate
)
782 goto need_revalidate
;
785 path
->dentry
= dentry
;
786 __follow_mount(path
);
790 dentry
= real_lookup(nd
->dentry
, name
, nd
);
796 dentry
= do_revalidate(dentry
, nd
);
804 return PTR_ERR(dentry
);
809 * This is the basic name resolution function, turning a pathname into
810 * the final dentry. We expect 'base' to be positive and a directory.
812 * Returns 0 and nd will have valid dentry and mnt on success.
813 * Returns error and drops reference to input namei data on failure.
815 static fastcall
int __link_path_walk(const char * name
, struct nameidata
*nd
)
820 unsigned int lookup_flags
= nd
->flags
;
827 inode
= nd
->dentry
->d_inode
;
829 lookup_flags
= LOOKUP_FOLLOW
| (nd
->flags
& LOOKUP_CONTINUE
);
831 /* At this point we know we have a real path component. */
837 nd
->flags
|= LOOKUP_CONTINUE
;
838 err
= exec_permission_lite(inode
, nd
);
840 err
= vfs_permission(nd
, MAY_EXEC
);
845 c
= *(const unsigned char *)name
;
847 hash
= init_name_hash();
850 hash
= partial_name_hash(c
, hash
);
851 c
= *(const unsigned char *)name
;
852 } while (c
&& (c
!= '/'));
853 this.len
= name
- (const char *) this.name
;
854 this.hash
= end_name_hash(hash
);
856 /* remove trailing slashes? */
859 while (*++name
== '/');
861 goto last_with_slashes
;
864 * "." and ".." are special - ".." especially so because it has
865 * to be able to know about the current root directory and
866 * parent relationships.
868 if (this.name
[0] == '.') switch (this.len
) {
872 if (this.name
[1] != '.')
875 inode
= nd
->dentry
->d_inode
;
881 * See if the low-level filesystem might want
882 * to use its own hash..
884 if (nd
->dentry
->d_op
&& nd
->dentry
->d_op
->d_hash
) {
885 err
= nd
->dentry
->d_op
->d_hash(nd
->dentry
, &this);
889 /* This does the actual lookups.. */
890 err
= do_lookup(nd
, &this, &next
);
895 inode
= next
.dentry
->d_inode
;
902 if (inode
->i_op
->follow_link
) {
903 err
= do_follow_link(&next
, nd
);
907 inode
= nd
->dentry
->d_inode
;
914 path_to_nameidata(&next
, nd
);
916 if (!inode
->i_op
->lookup
)
919 /* here ends the main loop */
922 lookup_flags
|= LOOKUP_FOLLOW
| LOOKUP_DIRECTORY
;
924 /* Clear LOOKUP_CONTINUE iff it was previously unset */
925 nd
->flags
&= lookup_flags
| ~LOOKUP_CONTINUE
;
926 if (lookup_flags
& LOOKUP_PARENT
)
928 if (this.name
[0] == '.') switch (this.len
) {
932 if (this.name
[1] != '.')
935 inode
= nd
->dentry
->d_inode
;
940 if (nd
->dentry
->d_op
&& nd
->dentry
->d_op
->d_hash
) {
941 err
= nd
->dentry
->d_op
->d_hash(nd
->dentry
, &this);
945 err
= do_lookup(nd
, &this, &next
);
948 inode
= next
.dentry
->d_inode
;
949 if ((lookup_flags
& LOOKUP_FOLLOW
)
950 && inode
&& inode
->i_op
&& inode
->i_op
->follow_link
) {
951 err
= do_follow_link(&next
, nd
);
954 inode
= nd
->dentry
->d_inode
;
956 path_to_nameidata(&next
, nd
);
960 if (lookup_flags
& LOOKUP_DIRECTORY
) {
962 if (!inode
->i_op
|| !inode
->i_op
->lookup
)
968 nd
->last_type
= LAST_NORM
;
969 if (this.name
[0] != '.')
972 nd
->last_type
= LAST_DOT
;
973 else if (this.len
== 2 && this.name
[1] == '.')
974 nd
->last_type
= LAST_DOTDOT
;
979 * We bypassed the ordinary revalidation routines.
980 * We may need to check the cached dentry for staleness.
982 if (nd
->dentry
&& nd
->dentry
->d_sb
&&
983 (nd
->dentry
->d_sb
->s_type
->fs_flags
& FS_REVAL_DOT
)) {
985 /* Note: we do not d_invalidate() */
986 if (!nd
->dentry
->d_op
->d_revalidate(nd
->dentry
, nd
))
992 dput_path(&next
, nd
);
1001 * Wrapper to retry pathname resolution whenever the underlying
1002 * file system returns an ESTALE.
1004 * Retry the whole path once, forcing real lookup requests
1005 * instead of relying on the dcache.
1007 int fastcall
link_path_walk(const char *name
, struct nameidata
*nd
)
1009 struct nameidata save
= *nd
;
1012 /* make sure the stuff we saved doesn't go away */
1016 result
= __link_path_walk(name
, nd
);
1017 if (result
== -ESTALE
) {
1021 nd
->flags
|= LOOKUP_REVAL
;
1022 result
= __link_path_walk(name
, nd
);
1031 int fastcall
path_walk(const char * name
, struct nameidata
*nd
)
1033 current
->total_link_count
= 0;
1034 return link_path_walk(name
, nd
);
1038 * SMP-safe: Returns 1 and nd will have valid dentry and mnt, if
1039 * everything is done. Returns 0 and drops input nd, if lookup failed;
1041 static int __emul_lookup_dentry(const char *name
, struct nameidata
*nd
)
1043 if (path_walk(name
, nd
))
1044 return 0; /* something went wrong... */
1046 if (!nd
->dentry
->d_inode
|| S_ISDIR(nd
->dentry
->d_inode
->i_mode
)) {
1047 struct dentry
*old_dentry
= nd
->dentry
;
1048 struct vfsmount
*old_mnt
= nd
->mnt
;
1049 struct qstr last
= nd
->last
;
1050 int last_type
= nd
->last_type
;
1051 struct fs_struct
*fs
= current
->fs
;
1054 * NAME was not found in alternate root or it's a directory.
1055 * Try to find it in the normal root:
1057 nd
->last_type
= LAST_ROOT
;
1058 read_lock(&fs
->lock
);
1059 nd
->mnt
= mntget(fs
->rootmnt
);
1060 nd
->dentry
= dget(fs
->root
);
1061 read_unlock(&fs
->lock
);
1062 if (path_walk(name
, nd
) == 0) {
1063 if (nd
->dentry
->d_inode
) {
1070 nd
->dentry
= old_dentry
;
1073 nd
->last_type
= last_type
;
1078 void set_fs_altroot(void)
1080 char *emul
= __emul_prefix();
1081 struct nameidata nd
;
1082 struct vfsmount
*mnt
= NULL
, *oldmnt
;
1083 struct dentry
*dentry
= NULL
, *olddentry
;
1085 struct fs_struct
*fs
= current
->fs
;
1089 err
= path_lookup(emul
, LOOKUP_FOLLOW
|LOOKUP_DIRECTORY
|LOOKUP_NOALT
, &nd
);
1095 write_lock(&fs
->lock
);
1096 oldmnt
= fs
->altrootmnt
;
1097 olddentry
= fs
->altroot
;
1098 fs
->altrootmnt
= mnt
;
1099 fs
->altroot
= dentry
;
1100 write_unlock(&fs
->lock
);
1107 /* Returns 0 and nd will be valid on success; Retuns error, otherwise. */
1108 static int fastcall
do_path_lookup(int dfd
, const char *name
,
1109 unsigned int flags
, struct nameidata
*nd
)
1114 struct fs_struct
*fs
= current
->fs
;
1116 nd
->last_type
= LAST_ROOT
; /* if there are only slashes... */
1121 read_lock(&fs
->lock
);
1122 if (fs
->altroot
&& !(nd
->flags
& LOOKUP_NOALT
)) {
1123 nd
->mnt
= mntget(fs
->altrootmnt
);
1124 nd
->dentry
= dget(fs
->altroot
);
1125 read_unlock(&fs
->lock
);
1126 if (__emul_lookup_dentry(name
,nd
))
1127 goto out
; /* found in altroot */
1128 read_lock(&fs
->lock
);
1130 nd
->mnt
= mntget(fs
->rootmnt
);
1131 nd
->dentry
= dget(fs
->root
);
1132 read_unlock(&fs
->lock
);
1133 } else if (dfd
== AT_FDCWD
) {
1134 read_lock(&fs
->lock
);
1135 nd
->mnt
= mntget(fs
->pwdmnt
);
1136 nd
->dentry
= dget(fs
->pwd
);
1137 read_unlock(&fs
->lock
);
1139 struct dentry
*dentry
;
1141 file
= fget_light(dfd
, &fput_needed
);
1146 dentry
= file
->f_dentry
;
1149 if (!S_ISDIR(dentry
->d_inode
->i_mode
))
1152 retval
= file_permission(file
, MAY_EXEC
);
1156 nd
->mnt
= mntget(file
->f_vfsmnt
);
1157 nd
->dentry
= dget(dentry
);
1159 fput_light(file
, fput_needed
);
1161 current
->total_link_count
= 0;
1162 retval
= link_path_walk(name
, nd
);
1164 if (likely(retval
== 0)) {
1165 if (unlikely(!audit_dummy_context() && nd
&& nd
->dentry
&&
1166 nd
->dentry
->d_inode
))
1167 audit_inode(name
, nd
->dentry
->d_inode
);
1173 fput_light(file
, fput_needed
);
1177 int fastcall
path_lookup(const char *name
, unsigned int flags
,
1178 struct nameidata
*nd
)
1180 return do_path_lookup(AT_FDCWD
, name
, flags
, nd
);
1183 static int __path_lookup_intent_open(int dfd
, const char *name
,
1184 unsigned int lookup_flags
, struct nameidata
*nd
,
1185 int open_flags
, int create_mode
)
1187 struct file
*filp
= get_empty_filp();
1192 nd
->intent
.open
.file
= filp
;
1193 nd
->intent
.open
.flags
= open_flags
;
1194 nd
->intent
.open
.create_mode
= create_mode
;
1195 err
= do_path_lookup(dfd
, name
, lookup_flags
|LOOKUP_OPEN
, nd
);
1196 if (IS_ERR(nd
->intent
.open
.file
)) {
1198 err
= PTR_ERR(nd
->intent
.open
.file
);
1201 } else if (err
!= 0)
1202 release_open_intent(nd
);
1207 * path_lookup_open - lookup a file path with open intent
1208 * @dfd: the directory to use as base, or AT_FDCWD
1209 * @name: pointer to file name
1210 * @lookup_flags: lookup intent flags
1211 * @nd: pointer to nameidata
1212 * @open_flags: open intent flags
1214 int path_lookup_open(int dfd
, const char *name
, unsigned int lookup_flags
,
1215 struct nameidata
*nd
, int open_flags
)
1217 return __path_lookup_intent_open(dfd
, name
, lookup_flags
, nd
,
1222 * path_lookup_create - lookup a file path with open + create intent
1223 * @dfd: the directory to use as base, or AT_FDCWD
1224 * @name: pointer to file name
1225 * @lookup_flags: lookup intent flags
1226 * @nd: pointer to nameidata
1227 * @open_flags: open intent flags
1228 * @create_mode: create intent flags
1230 static int path_lookup_create(int dfd
, const char *name
,
1231 unsigned int lookup_flags
, struct nameidata
*nd
,
1232 int open_flags
, int create_mode
)
1234 return __path_lookup_intent_open(dfd
, name
, lookup_flags
|LOOKUP_CREATE
,
1235 nd
, open_flags
, create_mode
);
1238 int __user_path_lookup_open(const char __user
*name
, unsigned int lookup_flags
,
1239 struct nameidata
*nd
, int open_flags
)
1241 char *tmp
= getname(name
);
1242 int err
= PTR_ERR(tmp
);
1245 err
= __path_lookup_intent_open(AT_FDCWD
, tmp
, lookup_flags
, nd
, open_flags
, 0);
1252 * Restricted form of lookup. Doesn't follow links, single-component only,
1253 * needs parent already locked. Doesn't follow mounts.
1256 static struct dentry
* __lookup_hash(struct qstr
*name
, struct dentry
* base
, struct nameidata
*nd
)
1258 struct dentry
* dentry
;
1259 struct inode
*inode
;
1262 inode
= base
->d_inode
;
1263 err
= permission(inode
, MAY_EXEC
, nd
);
1264 dentry
= ERR_PTR(err
);
1269 * See if the low-level filesystem might want
1270 * to use its own hash..
1272 if (base
->d_op
&& base
->d_op
->d_hash
) {
1273 err
= base
->d_op
->d_hash(base
, name
);
1274 dentry
= ERR_PTR(err
);
1279 dentry
= cached_lookup(base
, name
, nd
);
1281 struct dentry
*new = d_alloc(base
, name
);
1282 dentry
= ERR_PTR(-ENOMEM
);
1285 dentry
= inode
->i_op
->lookup(inode
, new, nd
);
1295 static struct dentry
*lookup_hash(struct nameidata
*nd
)
1297 return __lookup_hash(&nd
->last
, nd
->dentry
, nd
);
1301 struct dentry
* lookup_one_len(const char * name
, struct dentry
* base
, int len
)
1312 hash
= init_name_hash();
1314 c
= *(const unsigned char *)name
++;
1315 if (c
== '/' || c
== '\0')
1317 hash
= partial_name_hash(c
, hash
);
1319 this.hash
= end_name_hash(hash
);
1321 return __lookup_hash(&this, base
, NULL
);
1323 return ERR_PTR(-EACCES
);
1329 * is used by most simple commands to get the inode of a specified name.
1330 * Open, link etc use their own routines, but this is enough for things
1333 * namei exists in two versions: namei/lnamei. The only difference is
1334 * that namei follows links, while lnamei does not.
1337 int fastcall
__user_walk_fd(int dfd
, const char __user
*name
, unsigned flags
,
1338 struct nameidata
*nd
)
1340 char *tmp
= getname(name
);
1341 int err
= PTR_ERR(tmp
);
1344 err
= do_path_lookup(dfd
, tmp
, flags
, nd
);
1350 int fastcall
__user_walk(const char __user
*name
, unsigned flags
, struct nameidata
*nd
)
1352 return __user_walk_fd(AT_FDCWD
, name
, flags
, nd
);
1356 * It's inline, so penalty for filesystems that don't use sticky bit is
1359 static inline int check_sticky(struct inode
*dir
, struct inode
*inode
)
1361 if (!(dir
->i_mode
& S_ISVTX
))
1363 if (inode
->i_uid
== current
->fsuid
)
1365 if (dir
->i_uid
== current
->fsuid
)
1367 return !capable(CAP_FOWNER
);
1371 * Check whether we can remove a link victim from directory dir, check
1372 * whether the type of victim is right.
1373 * 1. We can't do it if dir is read-only (done in permission())
1374 * 2. We should have write and exec permissions on dir
1375 * 3. We can't remove anything from append-only dir
1376 * 4. We can't do anything with immutable dir (done in permission())
1377 * 5. If the sticky bit on dir is set we should either
1378 * a. be owner of dir, or
1379 * b. be owner of victim, or
1380 * c. have CAP_FOWNER capability
1381 * 6. If the victim is append-only or immutable we can't do antyhing with
1382 * links pointing to it.
1383 * 7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
1384 * 8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
1385 * 9. We can't remove a root or mountpoint.
1386 * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
1387 * nfs_async_unlink().
1389 static int may_delete(struct inode
*dir
,struct dentry
*victim
,int isdir
)
1393 if (!victim
->d_inode
)
1396 BUG_ON(victim
->d_parent
->d_inode
!= dir
);
1397 audit_inode_child(victim
->d_name
.name
, victim
->d_inode
, dir
);
1399 error
= permission(dir
,MAY_WRITE
| MAY_EXEC
, NULL
);
1404 if (check_sticky(dir
, victim
->d_inode
)||IS_APPEND(victim
->d_inode
)||
1405 IS_IMMUTABLE(victim
->d_inode
))
1408 if (!S_ISDIR(victim
->d_inode
->i_mode
))
1410 if (IS_ROOT(victim
))
1412 } else if (S_ISDIR(victim
->d_inode
->i_mode
))
1414 if (IS_DEADDIR(dir
))
1416 if (victim
->d_flags
& DCACHE_NFSFS_RENAMED
)
1421 /* Check whether we can create an object with dentry child in directory
1423 * 1. We can't do it if child already exists (open has special treatment for
1424 * this case, but since we are inlined it's OK)
1425 * 2. We can't do it if dir is read-only (done in permission())
1426 * 3. We should have write and exec permissions on dir
1427 * 4. We can't do it if dir is immutable (done in permission())
1429 static inline int may_create(struct inode
*dir
, struct dentry
*child
,
1430 struct nameidata
*nd
)
1434 if (IS_DEADDIR(dir
))
1436 return permission(dir
,MAY_WRITE
| MAY_EXEC
, nd
);
1440 * O_DIRECTORY translates into forcing a directory lookup.
1442 static inline int lookup_flags(unsigned int f
)
1444 unsigned long retval
= LOOKUP_FOLLOW
;
1447 retval
&= ~LOOKUP_FOLLOW
;
1449 if (f
& O_DIRECTORY
)
1450 retval
|= LOOKUP_DIRECTORY
;
1456 * p1 and p2 should be directories on the same fs.
1458 struct dentry
*lock_rename(struct dentry
*p1
, struct dentry
*p2
)
1463 mutex_lock_nested(&p1
->d_inode
->i_mutex
, I_MUTEX_PARENT
);
1467 mutex_lock(&p1
->d_inode
->i_sb
->s_vfs_rename_mutex
);
1469 for (p
= p1
; p
->d_parent
!= p
; p
= p
->d_parent
) {
1470 if (p
->d_parent
== p2
) {
1471 mutex_lock_nested(&p2
->d_inode
->i_mutex
, I_MUTEX_PARENT
);
1472 mutex_lock_nested(&p1
->d_inode
->i_mutex
, I_MUTEX_CHILD
);
1477 for (p
= p2
; p
->d_parent
!= p
; p
= p
->d_parent
) {
1478 if (p
->d_parent
== p1
) {
1479 mutex_lock_nested(&p1
->d_inode
->i_mutex
, I_MUTEX_PARENT
);
1480 mutex_lock_nested(&p2
->d_inode
->i_mutex
, I_MUTEX_CHILD
);
1485 mutex_lock_nested(&p1
->d_inode
->i_mutex
, I_MUTEX_PARENT
);
1486 mutex_lock_nested(&p2
->d_inode
->i_mutex
, I_MUTEX_CHILD
);
1490 void unlock_rename(struct dentry
*p1
, struct dentry
*p2
)
1492 mutex_unlock(&p1
->d_inode
->i_mutex
);
1494 mutex_unlock(&p2
->d_inode
->i_mutex
);
1495 mutex_unlock(&p1
->d_inode
->i_sb
->s_vfs_rename_mutex
);
1499 int vfs_create(struct inode
*dir
, struct dentry
*dentry
, int mode
,
1500 struct nameidata
*nd
)
1502 int error
= may_create(dir
, dentry
, nd
);
1507 if (!dir
->i_op
|| !dir
->i_op
->create
)
1508 return -EACCES
; /* shouldn't it be ENOSYS? */
1511 error
= security_inode_create(dir
, dentry
, mode
);
1515 error
= dir
->i_op
->create(dir
, dentry
, mode
, nd
);
1517 fsnotify_create(dir
, dentry
);
1521 int may_open(struct nameidata
*nd
, int acc_mode
, int flag
)
1523 struct dentry
*dentry
= nd
->dentry
;
1524 struct inode
*inode
= dentry
->d_inode
;
1530 if (S_ISLNK(inode
->i_mode
))
1533 if (S_ISDIR(inode
->i_mode
) && (flag
& FMODE_WRITE
))
1536 error
= vfs_permission(nd
, acc_mode
);
1541 * FIFO's, sockets and device files are special: they don't
1542 * actually live on the filesystem itself, and as such you
1543 * can write to them even if the filesystem is read-only.
1545 if (S_ISFIFO(inode
->i_mode
) || S_ISSOCK(inode
->i_mode
)) {
1547 } else if (S_ISBLK(inode
->i_mode
) || S_ISCHR(inode
->i_mode
)) {
1548 if (nd
->mnt
->mnt_flags
& MNT_NODEV
)
1552 } else if (IS_RDONLY(inode
) && (flag
& FMODE_WRITE
))
1555 * An append-only file must be opened in append mode for writing.
1557 if (IS_APPEND(inode
)) {
1558 if ((flag
& FMODE_WRITE
) && !(flag
& O_APPEND
))
1564 /* O_NOATIME can only be set by the owner or superuser */
1565 if (flag
& O_NOATIME
)
1566 if (current
->fsuid
!= inode
->i_uid
&& !capable(CAP_FOWNER
))
1570 * Ensure there are no outstanding leases on the file.
1572 error
= break_lease(inode
, flag
);
1576 if (flag
& O_TRUNC
) {
1577 error
= get_write_access(inode
);
1582 * Refuse to truncate files with mandatory locks held on them.
1584 error
= locks_verify_locked(inode
);
1588 error
= do_truncate(dentry
, 0, ATTR_MTIME
|ATTR_CTIME
, NULL
);
1590 put_write_access(inode
);
1594 if (flag
& FMODE_WRITE
)
1600 static int open_namei_create(struct nameidata
*nd
, struct path
*path
,
1604 struct dentry
*dir
= nd
->dentry
;
1606 if (!IS_POSIXACL(dir
->d_inode
))
1607 mode
&= ~current
->fs
->umask
;
1608 error
= vfs_create(dir
->d_inode
, path
->dentry
, mode
, nd
);
1609 mutex_unlock(&dir
->d_inode
->i_mutex
);
1611 nd
->dentry
= path
->dentry
;
1614 /* Don't check for write permission, don't truncate */
1615 return may_open(nd
, 0, flag
& ~O_TRUNC
);
1621 * namei for open - this is in fact almost the whole open-routine.
1623 * Note that the low bits of "flag" aren't the same as in the open
1624 * system call - they are 00 - no permissions needed
1625 * 01 - read permission needed
1626 * 10 - write permission needed
1627 * 11 - read/write permissions needed
1628 * which is a lot more logical, and also allows the "no perm" needed
1629 * for symlinks (where the permissions are checked later).
1632 int open_namei(int dfd
, const char *pathname
, int flag
,
1633 int mode
, struct nameidata
*nd
)
1635 int acc_mode
, error
;
1640 acc_mode
= ACC_MODE(flag
);
1642 /* O_TRUNC implies we need access checks for write permissions */
1644 acc_mode
|= MAY_WRITE
;
1646 /* Allow the LSM permission hook to distinguish append
1647 access from general write access. */
1648 if (flag
& O_APPEND
)
1649 acc_mode
|= MAY_APPEND
;
1652 * The simplest case - just a plain lookup.
1654 if (!(flag
& O_CREAT
)) {
1655 error
= path_lookup_open(dfd
, pathname
, lookup_flags(flag
),
1663 * Create - we need to know the parent.
1665 error
= path_lookup_create(dfd
,pathname
,LOOKUP_PARENT
,nd
,flag
,mode
);
1670 * We have the parent and last component. First of all, check
1671 * that we are not asked to creat(2) an obvious directory - that
1675 if (nd
->last_type
!= LAST_NORM
|| nd
->last
.name
[nd
->last
.len
])
1679 nd
->flags
&= ~LOOKUP_PARENT
;
1680 mutex_lock(&dir
->d_inode
->i_mutex
);
1681 path
.dentry
= lookup_hash(nd
);
1685 error
= PTR_ERR(path
.dentry
);
1686 if (IS_ERR(path
.dentry
)) {
1687 mutex_unlock(&dir
->d_inode
->i_mutex
);
1691 if (IS_ERR(nd
->intent
.open
.file
)) {
1692 mutex_unlock(&dir
->d_inode
->i_mutex
);
1693 error
= PTR_ERR(nd
->intent
.open
.file
);
1697 /* Negative dentry, just create the file */
1698 if (!path
.dentry
->d_inode
) {
1699 error
= open_namei_create(nd
, &path
, flag
, mode
);
1706 * It already exists.
1708 mutex_unlock(&dir
->d_inode
->i_mutex
);
1709 audit_inode_update(path
.dentry
->d_inode
);
1715 if (__follow_mount(&path
)) {
1717 if (flag
& O_NOFOLLOW
)
1722 if (!path
.dentry
->d_inode
)
1724 if (path
.dentry
->d_inode
->i_op
&& path
.dentry
->d_inode
->i_op
->follow_link
)
1727 path_to_nameidata(&path
, nd
);
1729 if (path
.dentry
->d_inode
&& S_ISDIR(path
.dentry
->d_inode
->i_mode
))
1732 error
= may_open(nd
, acc_mode
, flag
);
1738 dput_path(&path
, nd
);
1740 if (!IS_ERR(nd
->intent
.open
.file
))
1741 release_open_intent(nd
);
1747 if (flag
& O_NOFOLLOW
)
1750 * This is subtle. Instead of calling do_follow_link() we do the
1751 * thing by hands. The reason is that this way we have zero link_count
1752 * and path_walk() (called from ->follow_link) honoring LOOKUP_PARENT.
1753 * After that we have the parent and last component, i.e.
1754 * we are in the same situation as after the first path_walk().
1755 * Well, almost - if the last component is normal we get its copy
1756 * stored in nd->last.name and we will have to putname() it when we
1757 * are done. Procfs-like symlinks just set LAST_BIND.
1759 nd
->flags
|= LOOKUP_PARENT
;
1760 error
= security_inode_follow_link(path
.dentry
, nd
);
1763 error
= __do_follow_link(&path
, nd
);
1765 /* Does someone understand code flow here? Or it is only
1766 * me so stupid? Anathema to whoever designed this non-sense
1767 * with "intent.open".
1769 release_open_intent(nd
);
1772 nd
->flags
&= ~LOOKUP_PARENT
;
1773 if (nd
->last_type
== LAST_BIND
)
1776 if (nd
->last_type
!= LAST_NORM
)
1778 if (nd
->last
.name
[nd
->last
.len
]) {
1779 __putname(nd
->last
.name
);
1784 __putname(nd
->last
.name
);
1788 mutex_lock(&dir
->d_inode
->i_mutex
);
1789 path
.dentry
= lookup_hash(nd
);
1791 __putname(nd
->last
.name
);
1796 * lookup_create - lookup a dentry, creating it if it doesn't exist
1797 * @nd: nameidata info
1798 * @is_dir: directory flag
1800 * Simple function to lookup and return a dentry and create it
1801 * if it doesn't exist. Is SMP-safe.
1803 * Returns with nd->dentry->d_inode->i_mutex locked.
1805 struct dentry
*lookup_create(struct nameidata
*nd
, int is_dir
)
1807 struct dentry
*dentry
= ERR_PTR(-EEXIST
);
1809 mutex_lock_nested(&nd
->dentry
->d_inode
->i_mutex
, I_MUTEX_PARENT
);
1811 * Yucky last component or no last component at all?
1812 * (foo/., foo/.., /////)
1814 if (nd
->last_type
!= LAST_NORM
)
1816 nd
->flags
&= ~LOOKUP_PARENT
;
1817 nd
->flags
|= LOOKUP_CREATE
;
1818 nd
->intent
.open
.flags
= O_EXCL
;
1821 * Do the final lookup.
1823 dentry
= lookup_hash(nd
);
1828 * Special case - lookup gave negative, but... we had foo/bar/
1829 * From the vfs_mknod() POV we just have a negative dentry -
1830 * all is fine. Let's be bastards - you had / on the end, you've
1831 * been asking for (non-existent) directory. -ENOENT for you.
1833 if (!is_dir
&& nd
->last
.name
[nd
->last
.len
] && !dentry
->d_inode
)
1838 dentry
= ERR_PTR(-ENOENT
);
1842 EXPORT_SYMBOL_GPL(lookup_create
);
1844 int vfs_mknod(struct inode
*dir
, struct dentry
*dentry
, int mode
, dev_t dev
)
1846 int error
= may_create(dir
, dentry
, NULL
);
1851 if ((S_ISCHR(mode
) || S_ISBLK(mode
)) && !capable(CAP_MKNOD
))
1854 if (!dir
->i_op
|| !dir
->i_op
->mknod
)
1857 error
= security_inode_mknod(dir
, dentry
, mode
, dev
);
1862 error
= dir
->i_op
->mknod(dir
, dentry
, mode
, dev
);
1864 fsnotify_create(dir
, dentry
);
1868 asmlinkage
long sys_mknodat(int dfd
, const char __user
*filename
, int mode
,
1873 struct dentry
* dentry
;
1874 struct nameidata nd
;
1878 tmp
= getname(filename
);
1880 return PTR_ERR(tmp
);
1882 error
= do_path_lookup(dfd
, tmp
, LOOKUP_PARENT
, &nd
);
1885 dentry
= lookup_create(&nd
, 0);
1886 error
= PTR_ERR(dentry
);
1888 if (!IS_POSIXACL(nd
.dentry
->d_inode
))
1889 mode
&= ~current
->fs
->umask
;
1890 if (!IS_ERR(dentry
)) {
1891 switch (mode
& S_IFMT
) {
1892 case 0: case S_IFREG
:
1893 error
= vfs_create(nd
.dentry
->d_inode
,dentry
,mode
,&nd
);
1895 case S_IFCHR
: case S_IFBLK
:
1896 error
= vfs_mknod(nd
.dentry
->d_inode
,dentry
,mode
,
1897 new_decode_dev(dev
));
1899 case S_IFIFO
: case S_IFSOCK
:
1900 error
= vfs_mknod(nd
.dentry
->d_inode
,dentry
,mode
,0);
1910 mutex_unlock(&nd
.dentry
->d_inode
->i_mutex
);
1918 asmlinkage
long sys_mknod(const char __user
*filename
, int mode
, unsigned dev
)
1920 return sys_mknodat(AT_FDCWD
, filename
, mode
, dev
);
1923 int vfs_mkdir(struct inode
*dir
, struct dentry
*dentry
, int mode
)
1925 int error
= may_create(dir
, dentry
, NULL
);
1930 if (!dir
->i_op
|| !dir
->i_op
->mkdir
)
1933 mode
&= (S_IRWXUGO
|S_ISVTX
);
1934 error
= security_inode_mkdir(dir
, dentry
, mode
);
1939 error
= dir
->i_op
->mkdir(dir
, dentry
, mode
);
1941 fsnotify_mkdir(dir
, dentry
);
1945 asmlinkage
long sys_mkdirat(int dfd
, const char __user
*pathname
, int mode
)
1949 struct dentry
*dentry
;
1950 struct nameidata nd
;
1952 tmp
= getname(pathname
);
1953 error
= PTR_ERR(tmp
);
1957 error
= do_path_lookup(dfd
, tmp
, LOOKUP_PARENT
, &nd
);
1960 dentry
= lookup_create(&nd
, 1);
1961 error
= PTR_ERR(dentry
);
1965 if (!IS_POSIXACL(nd
.dentry
->d_inode
))
1966 mode
&= ~current
->fs
->umask
;
1967 error
= vfs_mkdir(nd
.dentry
->d_inode
, dentry
, mode
);
1970 mutex_unlock(&nd
.dentry
->d_inode
->i_mutex
);
1978 asmlinkage
long sys_mkdir(const char __user
*pathname
, int mode
)
1980 return sys_mkdirat(AT_FDCWD
, pathname
, mode
);
1984 * We try to drop the dentry early: we should have
1985 * a usage count of 2 if we're the only user of this
1986 * dentry, and if that is true (possibly after pruning
1987 * the dcache), then we drop the dentry now.
1989 * A low-level filesystem can, if it choses, legally
1992 * if (!d_unhashed(dentry))
1995 * if it cannot handle the case of removing a directory
1996 * that is still in use by something else..
1998 void dentry_unhash(struct dentry
*dentry
)
2001 shrink_dcache_parent(dentry
);
2002 spin_lock(&dcache_lock
);
2003 spin_lock(&dentry
->d_lock
);
2004 if (atomic_read(&dentry
->d_count
) == 2)
2006 spin_unlock(&dentry
->d_lock
);
2007 spin_unlock(&dcache_lock
);
2010 int vfs_rmdir(struct inode
*dir
, struct dentry
*dentry
)
2012 int error
= may_delete(dir
, dentry
, 1);
2017 if (!dir
->i_op
|| !dir
->i_op
->rmdir
)
2022 mutex_lock(&dentry
->d_inode
->i_mutex
);
2023 dentry_unhash(dentry
);
2024 if (d_mountpoint(dentry
))
2027 error
= security_inode_rmdir(dir
, dentry
);
2029 error
= dir
->i_op
->rmdir(dir
, dentry
);
2031 dentry
->d_inode
->i_flags
|= S_DEAD
;
2034 mutex_unlock(&dentry
->d_inode
->i_mutex
);
2043 static long do_rmdir(int dfd
, const char __user
*pathname
)
2047 struct dentry
*dentry
;
2048 struct nameidata nd
;
2050 name
= getname(pathname
);
2052 return PTR_ERR(name
);
2054 error
= do_path_lookup(dfd
, name
, LOOKUP_PARENT
, &nd
);
2058 switch(nd
.last_type
) {
2069 mutex_lock_nested(&nd
.dentry
->d_inode
->i_mutex
, I_MUTEX_PARENT
);
2070 dentry
= lookup_hash(&nd
);
2071 error
= PTR_ERR(dentry
);
2074 error
= vfs_rmdir(nd
.dentry
->d_inode
, dentry
);
2077 mutex_unlock(&nd
.dentry
->d_inode
->i_mutex
);
2085 asmlinkage
long sys_rmdir(const char __user
*pathname
)
2087 return do_rmdir(AT_FDCWD
, pathname
);
2090 int vfs_unlink(struct inode
*dir
, struct dentry
*dentry
)
2092 int error
= may_delete(dir
, dentry
, 0);
2097 if (!dir
->i_op
|| !dir
->i_op
->unlink
)
2102 mutex_lock(&dentry
->d_inode
->i_mutex
);
2103 if (d_mountpoint(dentry
))
2106 error
= security_inode_unlink(dir
, dentry
);
2108 error
= dir
->i_op
->unlink(dir
, dentry
);
2110 mutex_unlock(&dentry
->d_inode
->i_mutex
);
2112 /* We don't d_delete() NFS sillyrenamed files--they still exist. */
2113 if (!error
&& !(dentry
->d_flags
& DCACHE_NFSFS_RENAMED
)) {
2121 * Make sure that the actual truncation of the file will occur outside its
2122 * directory's i_mutex. Truncate can take a long time if there is a lot of
2123 * writeout happening, and we don't want to prevent access to the directory
2124 * while waiting on the I/O.
2126 static long do_unlinkat(int dfd
, const char __user
*pathname
)
2130 struct dentry
*dentry
;
2131 struct nameidata nd
;
2132 struct inode
*inode
= NULL
;
2134 name
= getname(pathname
);
2136 return PTR_ERR(name
);
2138 error
= do_path_lookup(dfd
, name
, LOOKUP_PARENT
, &nd
);
2142 if (nd
.last_type
!= LAST_NORM
)
2144 mutex_lock_nested(&nd
.dentry
->d_inode
->i_mutex
, I_MUTEX_PARENT
);
2145 dentry
= lookup_hash(&nd
);
2146 error
= PTR_ERR(dentry
);
2147 if (!IS_ERR(dentry
)) {
2148 /* Why not before? Because we want correct error value */
2149 if (nd
.last
.name
[nd
.last
.len
])
2151 inode
= dentry
->d_inode
;
2153 atomic_inc(&inode
->i_count
);
2154 error
= vfs_unlink(nd
.dentry
->d_inode
, dentry
);
2158 mutex_unlock(&nd
.dentry
->d_inode
->i_mutex
);
2160 iput(inode
); /* truncate the inode here */
2168 error
= !dentry
->d_inode
? -ENOENT
:
2169 S_ISDIR(dentry
->d_inode
->i_mode
) ? -EISDIR
: -ENOTDIR
;
2173 asmlinkage
long sys_unlinkat(int dfd
, const char __user
*pathname
, int flag
)
2175 if ((flag
& ~AT_REMOVEDIR
) != 0)
2178 if (flag
& AT_REMOVEDIR
)
2179 return do_rmdir(dfd
, pathname
);
2181 return do_unlinkat(dfd
, pathname
);
2184 asmlinkage
long sys_unlink(const char __user
*pathname
)
2186 return do_unlinkat(AT_FDCWD
, pathname
);
2189 int vfs_symlink(struct inode
*dir
, struct dentry
*dentry
, const char *oldname
, int mode
)
2191 int error
= may_create(dir
, dentry
, NULL
);
2196 if (!dir
->i_op
|| !dir
->i_op
->symlink
)
2199 error
= security_inode_symlink(dir
, dentry
, oldname
);
2204 error
= dir
->i_op
->symlink(dir
, dentry
, oldname
);
2206 fsnotify_create(dir
, dentry
);
2210 asmlinkage
long sys_symlinkat(const char __user
*oldname
,
2211 int newdfd
, const char __user
*newname
)
2216 struct dentry
*dentry
;
2217 struct nameidata nd
;
2219 from
= getname(oldname
);
2221 return PTR_ERR(from
);
2222 to
= getname(newname
);
2223 error
= PTR_ERR(to
);
2227 error
= do_path_lookup(newdfd
, to
, LOOKUP_PARENT
, &nd
);
2230 dentry
= lookup_create(&nd
, 0);
2231 error
= PTR_ERR(dentry
);
2235 error
= vfs_symlink(nd
.dentry
->d_inode
, dentry
, from
, S_IALLUGO
);
2238 mutex_unlock(&nd
.dentry
->d_inode
->i_mutex
);
2247 asmlinkage
long sys_symlink(const char __user
*oldname
, const char __user
*newname
)
2249 return sys_symlinkat(oldname
, AT_FDCWD
, newname
);
2252 int vfs_link(struct dentry
*old_dentry
, struct inode
*dir
, struct dentry
*new_dentry
)
2254 struct inode
*inode
= old_dentry
->d_inode
;
2260 error
= may_create(dir
, new_dentry
, NULL
);
2264 if (dir
->i_sb
!= inode
->i_sb
)
2268 * A link to an append-only or immutable file cannot be created.
2270 if (IS_APPEND(inode
) || IS_IMMUTABLE(inode
))
2272 if (!dir
->i_op
|| !dir
->i_op
->link
)
2274 if (S_ISDIR(old_dentry
->d_inode
->i_mode
))
2277 error
= security_inode_link(old_dentry
, dir
, new_dentry
);
2281 mutex_lock(&old_dentry
->d_inode
->i_mutex
);
2283 error
= dir
->i_op
->link(old_dentry
, dir
, new_dentry
);
2284 mutex_unlock(&old_dentry
->d_inode
->i_mutex
);
2286 fsnotify_create(dir
, new_dentry
);
2291 * Hardlinks are often used in delicate situations. We avoid
2292 * security-related surprises by not following symlinks on the
2295 * We don't follow them on the oldname either to be compatible
2296 * with linux 2.0, and to avoid hard-linking to directories
2297 * and other special files. --ADM
2299 asmlinkage
long sys_linkat(int olddfd
, const char __user
*oldname
,
2300 int newdfd
, const char __user
*newname
,
2303 struct dentry
*new_dentry
;
2304 struct nameidata nd
, old_nd
;
2308 if ((flags
& ~AT_SYMLINK_FOLLOW
) != 0)
2311 to
= getname(newname
);
2315 error
= __user_walk_fd(olddfd
, oldname
,
2316 flags
& AT_SYMLINK_FOLLOW
? LOOKUP_FOLLOW
: 0,
2320 error
= do_path_lookup(newdfd
, to
, LOOKUP_PARENT
, &nd
);
2324 if (old_nd
.mnt
!= nd
.mnt
)
2326 new_dentry
= lookup_create(&nd
, 0);
2327 error
= PTR_ERR(new_dentry
);
2328 if (IS_ERR(new_dentry
))
2330 error
= vfs_link(old_nd
.dentry
, nd
.dentry
->d_inode
, new_dentry
);
2333 mutex_unlock(&nd
.dentry
->d_inode
->i_mutex
);
2337 path_release(&old_nd
);
2344 asmlinkage
long sys_link(const char __user
*oldname
, const char __user
*newname
)
2346 return sys_linkat(AT_FDCWD
, oldname
, AT_FDCWD
, newname
, 0);
2350 * The worst of all namespace operations - renaming directory. "Perverted"
2351 * doesn't even start to describe it. Somebody in UCB had a heck of a trip...
2353 * a) we can get into loop creation. Check is done in is_subdir().
2354 * b) race potential - two innocent renames can create a loop together.
2355 * That's where 4.4 screws up. Current fix: serialization on
2356 * sb->s_vfs_rename_mutex. We might be more accurate, but that's another
2358 * c) we have to lock _three_ objects - parents and victim (if it exists).
2359 * And that - after we got ->i_mutex on parents (until then we don't know
2360 * whether the target exists). Solution: try to be smart with locking
2361 * order for inodes. We rely on the fact that tree topology may change
2362 * only under ->s_vfs_rename_mutex _and_ that parent of the object we
2363 * move will be locked. Thus we can rank directories by the tree
2364 * (ancestors first) and rank all non-directories after them.
2365 * That works since everybody except rename does "lock parent, lookup,
2366 * lock child" and rename is under ->s_vfs_rename_mutex.
2367 * HOWEVER, it relies on the assumption that any object with ->lookup()
2368 * has no more than 1 dentry. If "hybrid" objects will ever appear,
2369 * we'd better make sure that there's no link(2) for them.
2370 * d) some filesystems don't support opened-but-unlinked directories,
2371 * either because of layout or because they are not ready to deal with
2372 * all cases correctly. The latter will be fixed (taking this sort of
2373 * stuff into VFS), but the former is not going away. Solution: the same
2374 * trick as in rmdir().
2375 * e) conversion from fhandle to dentry may come in the wrong moment - when
2376 * we are removing the target. Solution: we will have to grab ->i_mutex
2377 * in the fhandle_to_dentry code. [FIXME - current nfsfh.c relies on
2378 * ->i_mutex on parents, which works but leads to some truely excessive
2381 static int vfs_rename_dir(struct inode
*old_dir
, struct dentry
*old_dentry
,
2382 struct inode
*new_dir
, struct dentry
*new_dentry
)
2385 struct inode
*target
;
2388 * If we are going to change the parent - check write permissions,
2389 * we'll need to flip '..'.
2391 if (new_dir
!= old_dir
) {
2392 error
= permission(old_dentry
->d_inode
, MAY_WRITE
, NULL
);
2397 error
= security_inode_rename(old_dir
, old_dentry
, new_dir
, new_dentry
);
2401 target
= new_dentry
->d_inode
;
2403 mutex_lock(&target
->i_mutex
);
2404 dentry_unhash(new_dentry
);
2406 if (d_mountpoint(old_dentry
)||d_mountpoint(new_dentry
))
2409 error
= old_dir
->i_op
->rename(old_dir
, old_dentry
, new_dir
, new_dentry
);
2412 target
->i_flags
|= S_DEAD
;
2413 mutex_unlock(&target
->i_mutex
);
2414 if (d_unhashed(new_dentry
))
2415 d_rehash(new_dentry
);
2419 if (!(old_dir
->i_sb
->s_type
->fs_flags
& FS_RENAME_DOES_D_MOVE
))
2420 d_move(old_dentry
,new_dentry
);
2424 static int vfs_rename_other(struct inode
*old_dir
, struct dentry
*old_dentry
,
2425 struct inode
*new_dir
, struct dentry
*new_dentry
)
2427 struct inode
*target
;
2430 error
= security_inode_rename(old_dir
, old_dentry
, new_dir
, new_dentry
);
2435 target
= new_dentry
->d_inode
;
2437 mutex_lock(&target
->i_mutex
);
2438 if (d_mountpoint(old_dentry
)||d_mountpoint(new_dentry
))
2441 error
= old_dir
->i_op
->rename(old_dir
, old_dentry
, new_dir
, new_dentry
);
2443 if (!(old_dir
->i_sb
->s_type
->fs_flags
& FS_RENAME_DOES_D_MOVE
))
2444 d_move(old_dentry
, new_dentry
);
2447 mutex_unlock(&target
->i_mutex
);
2452 int vfs_rename(struct inode
*old_dir
, struct dentry
*old_dentry
,
2453 struct inode
*new_dir
, struct dentry
*new_dentry
)
2456 int is_dir
= S_ISDIR(old_dentry
->d_inode
->i_mode
);
2457 const char *old_name
;
2459 if (old_dentry
->d_inode
== new_dentry
->d_inode
)
2462 error
= may_delete(old_dir
, old_dentry
, is_dir
);
2466 if (!new_dentry
->d_inode
)
2467 error
= may_create(new_dir
, new_dentry
, NULL
);
2469 error
= may_delete(new_dir
, new_dentry
, is_dir
);
2473 if (!old_dir
->i_op
|| !old_dir
->i_op
->rename
)
2476 DQUOT_INIT(old_dir
);
2477 DQUOT_INIT(new_dir
);
2479 old_name
= fsnotify_oldname_init(old_dentry
->d_name
.name
);
2482 error
= vfs_rename_dir(old_dir
,old_dentry
,new_dir
,new_dentry
);
2484 error
= vfs_rename_other(old_dir
,old_dentry
,new_dir
,new_dentry
);
2486 const char *new_name
= old_dentry
->d_name
.name
;
2487 fsnotify_move(old_dir
, new_dir
, old_name
, new_name
, is_dir
,
2488 new_dentry
->d_inode
, old_dentry
->d_inode
);
2490 fsnotify_oldname_free(old_name
);
2495 static int do_rename(int olddfd
, const char *oldname
,
2496 int newdfd
, const char *newname
)
2499 struct dentry
* old_dir
, * new_dir
;
2500 struct dentry
* old_dentry
, *new_dentry
;
2501 struct dentry
* trap
;
2502 struct nameidata oldnd
, newnd
;
2504 error
= do_path_lookup(olddfd
, oldname
, LOOKUP_PARENT
, &oldnd
);
2508 error
= do_path_lookup(newdfd
, newname
, LOOKUP_PARENT
, &newnd
);
2513 if (oldnd
.mnt
!= newnd
.mnt
)
2516 old_dir
= oldnd
.dentry
;
2518 if (oldnd
.last_type
!= LAST_NORM
)
2521 new_dir
= newnd
.dentry
;
2522 if (newnd
.last_type
!= LAST_NORM
)
2525 trap
= lock_rename(new_dir
, old_dir
);
2527 old_dentry
= lookup_hash(&oldnd
);
2528 error
= PTR_ERR(old_dentry
);
2529 if (IS_ERR(old_dentry
))
2531 /* source must exist */
2533 if (!old_dentry
->d_inode
)
2535 /* unless the source is a directory trailing slashes give -ENOTDIR */
2536 if (!S_ISDIR(old_dentry
->d_inode
->i_mode
)) {
2538 if (oldnd
.last
.name
[oldnd
.last
.len
])
2540 if (newnd
.last
.name
[newnd
.last
.len
])
2543 /* source should not be ancestor of target */
2545 if (old_dentry
== trap
)
2547 new_dentry
= lookup_hash(&newnd
);
2548 error
= PTR_ERR(new_dentry
);
2549 if (IS_ERR(new_dentry
))
2551 /* target should not be an ancestor of source */
2553 if (new_dentry
== trap
)
2556 error
= vfs_rename(old_dir
->d_inode
, old_dentry
,
2557 new_dir
->d_inode
, new_dentry
);
2563 unlock_rename(new_dir
, old_dir
);
2565 path_release(&newnd
);
2567 path_release(&oldnd
);
2572 asmlinkage
long sys_renameat(int olddfd
, const char __user
*oldname
,
2573 int newdfd
, const char __user
*newname
)
2579 from
= getname(oldname
);
2581 return PTR_ERR(from
);
2582 to
= getname(newname
);
2583 error
= PTR_ERR(to
);
2585 error
= do_rename(olddfd
, from
, newdfd
, to
);
2592 asmlinkage
long sys_rename(const char __user
*oldname
, const char __user
*newname
)
2594 return sys_renameat(AT_FDCWD
, oldname
, AT_FDCWD
, newname
);
2597 int vfs_readlink(struct dentry
*dentry
, char __user
*buffer
, int buflen
, const char *link
)
2601 len
= PTR_ERR(link
);
2606 if (len
> (unsigned) buflen
)
2608 if (copy_to_user(buffer
, link
, len
))
2615 * A helper for ->readlink(). This should be used *ONLY* for symlinks that
2616 * have ->follow_link() touching nd only in nd_set_link(). Using (or not
2617 * using) it for any given inode is up to filesystem.
2619 int generic_readlink(struct dentry
*dentry
, char __user
*buffer
, int buflen
)
2621 struct nameidata nd
;
2625 cookie
= dentry
->d_inode
->i_op
->follow_link(dentry
, &nd
);
2626 if (!IS_ERR(cookie
)) {
2627 int res
= vfs_readlink(dentry
, buffer
, buflen
, nd_get_link(&nd
));
2628 if (dentry
->d_inode
->i_op
->put_link
)
2629 dentry
->d_inode
->i_op
->put_link(dentry
, &nd
, cookie
);
2630 cookie
= ERR_PTR(res
);
2632 return PTR_ERR(cookie
);
2635 int vfs_follow_link(struct nameidata
*nd
, const char *link
)
2637 return __vfs_follow_link(nd
, link
);
2640 /* get the link contents into pagecache */
2641 static char *page_getlink(struct dentry
* dentry
, struct page
**ppage
)
2644 struct address_space
*mapping
= dentry
->d_inode
->i_mapping
;
2645 page
= read_mapping_page(mapping
, 0, NULL
);
2648 wait_on_page_locked(page
);
2649 if (!PageUptodate(page
))
2655 page_cache_release(page
);
2656 return ERR_PTR(-EIO
);
2662 int page_readlink(struct dentry
*dentry
, char __user
*buffer
, int buflen
)
2664 struct page
*page
= NULL
;
2665 char *s
= page_getlink(dentry
, &page
);
2666 int res
= vfs_readlink(dentry
,buffer
,buflen
,s
);
2669 page_cache_release(page
);
2674 void *page_follow_link_light(struct dentry
*dentry
, struct nameidata
*nd
)
2676 struct page
*page
= NULL
;
2677 nd_set_link(nd
, page_getlink(dentry
, &page
));
2681 void page_put_link(struct dentry
*dentry
, struct nameidata
*nd
, void *cookie
)
2683 struct page
*page
= cookie
;
2687 page_cache_release(page
);
2691 int __page_symlink(struct inode
*inode
, const char *symname
, int len
,
2694 struct address_space
*mapping
= inode
->i_mapping
;
2700 page
= find_or_create_page(mapping
, 0, gfp_mask
);
2703 err
= mapping
->a_ops
->prepare_write(NULL
, page
, 0, len
-1);
2704 if (err
== AOP_TRUNCATED_PAGE
) {
2705 page_cache_release(page
);
2710 kaddr
= kmap_atomic(page
, KM_USER0
);
2711 memcpy(kaddr
, symname
, len
-1);
2712 kunmap_atomic(kaddr
, KM_USER0
);
2713 err
= mapping
->a_ops
->commit_write(NULL
, page
, 0, len
-1);
2714 if (err
== AOP_TRUNCATED_PAGE
) {
2715 page_cache_release(page
);
2721 * Notice that we are _not_ going to block here - end of page is
2722 * unmapped, so this will only try to map the rest of page, see
2723 * that it is unmapped (typically even will not look into inode -
2724 * ->i_size will be enough for everything) and zero it out.
2725 * OTOH it's obviously correct and should make the page up-to-date.
2727 if (!PageUptodate(page
)) {
2728 err
= mapping
->a_ops
->readpage(NULL
, page
);
2729 if (err
!= AOP_TRUNCATED_PAGE
)
2730 wait_on_page_locked(page
);
2734 page_cache_release(page
);
2737 mark_inode_dirty(inode
);
2741 page_cache_release(page
);
2746 int page_symlink(struct inode
*inode
, const char *symname
, int len
)
2748 return __page_symlink(inode
, symname
, len
,
2749 mapping_gfp_mask(inode
->i_mapping
));
2752 struct inode_operations page_symlink_inode_operations
= {
2753 .readlink
= generic_readlink
,
2754 .follow_link
= page_follow_link_light
,
2755 .put_link
= page_put_link
,
2758 EXPORT_SYMBOL(__user_walk
);
2759 EXPORT_SYMBOL(__user_walk_fd
);
2760 EXPORT_SYMBOL(follow_down
);
2761 EXPORT_SYMBOL(follow_up
);
2762 EXPORT_SYMBOL(get_write_access
); /* binfmt_aout */
2763 EXPORT_SYMBOL(getname
);
2764 EXPORT_SYMBOL(lock_rename
);
2765 EXPORT_SYMBOL(lookup_one_len
);
2766 EXPORT_SYMBOL(page_follow_link_light
);
2767 EXPORT_SYMBOL(page_put_link
);
2768 EXPORT_SYMBOL(page_readlink
);
2769 EXPORT_SYMBOL(__page_symlink
);
2770 EXPORT_SYMBOL(page_symlink
);
2771 EXPORT_SYMBOL(page_symlink_inode_operations
);
2772 EXPORT_SYMBOL(path_lookup
);
2773 EXPORT_SYMBOL(path_release
);
2774 EXPORT_SYMBOL(path_walk
);
2775 EXPORT_SYMBOL(permission
);
2776 EXPORT_SYMBOL(vfs_permission
);
2777 EXPORT_SYMBOL(file_permission
);
2778 EXPORT_SYMBOL(unlock_rename
);
2779 EXPORT_SYMBOL(vfs_create
);
2780 EXPORT_SYMBOL(vfs_follow_link
);
2781 EXPORT_SYMBOL(vfs_link
);
2782 EXPORT_SYMBOL(vfs_mkdir
);
2783 EXPORT_SYMBOL(vfs_mknod
);
2784 EXPORT_SYMBOL(generic_permission
);
2785 EXPORT_SYMBOL(vfs_readlink
);
2786 EXPORT_SYMBOL(vfs_rename
);
2787 EXPORT_SYMBOL(vfs_rmdir
);
2788 EXPORT_SYMBOL(vfs_symlink
);
2789 EXPORT_SYMBOL(vfs_unlink
);
2790 EXPORT_SYMBOL(dentry_unhash
);
2791 EXPORT_SYMBOL(generic_readlink
);