1 /* -*- c -*- --------------------------------------------------------------- *
3 * linux/fs/autofs/root.c
5 * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
6 * Copyright 1999-2000 Jeremy Fitzhardinge <jeremy@goop.org>
7 * Copyright 2001-2006 Ian Kent <raven@themaw.net>
9 * This file is part of the Linux kernel and is made available under
10 * the terms of the GNU General Public License, version 2, or at your
11 * option, any later version, incorporated herein by reference.
13 * ------------------------------------------------------------------------- */
15 #include <linux/capability.h>
16 #include <linux/errno.h>
17 #include <linux/stat.h>
18 #include <linux/param.h>
19 #include <linux/time.h>
22 static int autofs4_dir_symlink(struct inode
*,struct dentry
*,const char *);
23 static int autofs4_dir_unlink(struct inode
*,struct dentry
*);
24 static int autofs4_dir_rmdir(struct inode
*,struct dentry
*);
25 static int autofs4_dir_mkdir(struct inode
*,struct dentry
*,int);
26 static int autofs4_root_ioctl(struct inode
*, struct file
*,unsigned int,unsigned long);
27 static int autofs4_dir_open(struct inode
*inode
, struct file
*file
);
28 static int autofs4_root_readdir(struct file
* filp
, void * dirent
, filldir_t filldir
);
29 static struct dentry
*autofs4_lookup(struct inode
*,struct dentry
*, struct nameidata
*);
30 static void *autofs4_follow_link(struct dentry
*, struct nameidata
*);
32 #define TRIGGER_FLAGS (LOOKUP_CONTINUE | LOOKUP_DIRECTORY)
33 #define TRIGGER_INTENTS (LOOKUP_OPEN | LOOKUP_CREATE)
35 const struct file_operations autofs4_root_operations
= {
36 .open
= dcache_dir_open
,
37 .release
= dcache_dir_close
,
38 .read
= generic_read_dir
,
39 .readdir
= autofs4_root_readdir
,
40 .ioctl
= autofs4_root_ioctl
,
43 const struct file_operations autofs4_dir_operations
= {
44 .open
= autofs4_dir_open
,
45 .release
= dcache_dir_close
,
46 .read
= generic_read_dir
,
47 .readdir
= dcache_readdir
,
50 const struct inode_operations autofs4_indirect_root_inode_operations
= {
51 .lookup
= autofs4_lookup
,
52 .unlink
= autofs4_dir_unlink
,
53 .symlink
= autofs4_dir_symlink
,
54 .mkdir
= autofs4_dir_mkdir
,
55 .rmdir
= autofs4_dir_rmdir
,
58 const struct inode_operations autofs4_direct_root_inode_operations
= {
59 .lookup
= autofs4_lookup
,
60 .unlink
= autofs4_dir_unlink
,
61 .mkdir
= autofs4_dir_mkdir
,
62 .rmdir
= autofs4_dir_rmdir
,
63 .follow_link
= autofs4_follow_link
,
66 const struct inode_operations autofs4_dir_inode_operations
= {
67 .lookup
= autofs4_lookup
,
68 .unlink
= autofs4_dir_unlink
,
69 .symlink
= autofs4_dir_symlink
,
70 .mkdir
= autofs4_dir_mkdir
,
71 .rmdir
= autofs4_dir_rmdir
,
74 static int autofs4_root_readdir(struct file
*file
, void *dirent
,
77 struct autofs_sb_info
*sbi
= autofs4_sbi(file
->f_path
.dentry
->d_sb
);
78 int oz_mode
= autofs4_oz_mode(sbi
);
80 DPRINTK("called, filp->f_pos = %lld", file
->f_pos
);
83 * Don't set reghost flag if:
84 * 1) f_pos is larger than zero -- we've already been here.
85 * 2) we haven't even enabled reghosting in the 1st place.
86 * 3) this is the daemon doing a readdir
88 if (oz_mode
&& file
->f_pos
== 0 && sbi
->reghost_enabled
)
89 sbi
->needs_reghost
= 1;
91 DPRINTK("needs_reghost = %d", sbi
->needs_reghost
);
93 return dcache_readdir(file
, dirent
, filldir
);
96 static int autofs4_dir_open(struct inode
*inode
, struct file
*file
)
98 struct dentry
*dentry
= file
->f_path
.dentry
;
99 struct autofs_sb_info
*sbi
= autofs4_sbi(dentry
->d_sb
);
101 DPRINTK("file=%p dentry=%p %.*s",
102 file
, dentry
, dentry
->d_name
.len
, dentry
->d_name
.name
);
104 if (autofs4_oz_mode(sbi
))
108 * An empty directory in an autofs file system is always a
109 * mount point. The daemon must have failed to mount this
110 * during lookup so it doesn't exist. This can happen, for
111 * example, if user space returns an incorrect status for a
112 * mount request. Otherwise we're doing a readdir on the
113 * autofs file system so just let the libfs routines handle
116 spin_lock(&dcache_lock
);
117 if (!d_mountpoint(dentry
) && __simple_empty(dentry
)) {
118 spin_unlock(&dcache_lock
);
121 spin_unlock(&dcache_lock
);
124 return dcache_dir_open(inode
, file
);
127 static int try_to_fill_dentry(struct dentry
*dentry
, int flags
)
129 struct autofs_sb_info
*sbi
= autofs4_sbi(dentry
->d_sb
);
130 struct autofs_info
*ino
= autofs4_dentry_ino(dentry
);
133 /* Block on any pending expiry here; invalidate the dentry
134 when expiration is done to trigger mount request with a new
136 spin_lock(&sbi
->fs_lock
);
137 if (ino
->flags
& AUTOFS_INF_EXPIRING
) {
138 spin_unlock(&sbi
->fs_lock
);
140 DPRINTK("waiting for expire %p name=%.*s",
141 dentry
, dentry
->d_name
.len
, dentry
->d_name
.name
);
143 status
= autofs4_wait(sbi
, dentry
, NFY_NONE
);
144 wait_for_completion(&ino
->expire_complete
);
146 DPRINTK("expire done status=%d", status
);
149 * If the directory still exists the mount request must
150 * continue otherwise it can't be followed at the right
151 * time during the walk.
153 status
= d_invalidate(dentry
);
154 if (status
!= -EBUSY
)
159 spin_unlock(&sbi
->fs_lock
);
161 DPRINTK("dentry=%p %.*s ino=%p",
162 dentry
, dentry
->d_name
.len
, dentry
->d_name
.name
, dentry
->d_inode
);
165 * Wait for a pending mount, triggering one if there
168 if (dentry
->d_inode
== NULL
) {
169 DPRINTK("waiting for mount name=%.*s",
170 dentry
->d_name
.len
, dentry
->d_name
.name
);
172 status
= autofs4_wait(sbi
, dentry
, NFY_MOUNT
);
174 DPRINTK("mount done status=%d", status
);
176 /* Turn this into a real negative dentry? */
177 if (status
== -ENOENT
) {
178 spin_lock(&dentry
->d_lock
);
179 dentry
->d_flags
&= ~DCACHE_AUTOFS_PENDING
;
180 spin_unlock(&dentry
->d_lock
);
183 /* Return a negative dentry, but leave it "pending" */
186 /* Trigger mount for path component or follow link */
187 } else if (dentry
->d_flags
& DCACHE_AUTOFS_PENDING
||
188 flags
& (TRIGGER_FLAGS
| TRIGGER_INTENTS
) ||
189 current
->link_count
) {
190 DPRINTK("waiting for mount name=%.*s",
191 dentry
->d_name
.len
, dentry
->d_name
.name
);
193 spin_lock(&dentry
->d_lock
);
194 dentry
->d_flags
|= DCACHE_AUTOFS_PENDING
;
195 spin_unlock(&dentry
->d_lock
);
196 status
= autofs4_wait(sbi
, dentry
, NFY_MOUNT
);
198 DPRINTK("mount done status=%d", status
);
201 spin_lock(&dentry
->d_lock
);
202 dentry
->d_flags
&= ~DCACHE_AUTOFS_PENDING
;
203 spin_unlock(&dentry
->d_lock
);
208 /* Initialize expiry counter after successful mount */
210 ino
->last_used
= jiffies
;
212 spin_lock(&dentry
->d_lock
);
213 dentry
->d_flags
&= ~DCACHE_AUTOFS_PENDING
;
214 spin_unlock(&dentry
->d_lock
);
219 /* For autofs direct mounts the follow link triggers the mount */
220 static void *autofs4_follow_link(struct dentry
*dentry
, struct nameidata
*nd
)
222 struct autofs_sb_info
*sbi
= autofs4_sbi(dentry
->d_sb
);
223 struct autofs_info
*ino
= autofs4_dentry_ino(dentry
);
224 int oz_mode
= autofs4_oz_mode(sbi
);
225 unsigned int lookup_type
;
228 DPRINTK("dentry=%p %.*s oz_mode=%d nd->flags=%d",
229 dentry
, dentry
->d_name
.len
, dentry
->d_name
.name
, oz_mode
,
232 * For an expire of a covered direct or offset mount we need
233 * to beeak out of follow_down() at the autofs mount trigger
234 * (d_mounted--), so we can see the expiring flag, and manage
235 * the blocking and following here until the expire is completed.
238 spin_lock(&sbi
->fs_lock
);
239 if (ino
->flags
& AUTOFS_INF_EXPIRING
) {
240 spin_unlock(&sbi
->fs_lock
);
241 /* Follow down to our covering mount. */
242 if (!follow_down(&nd
->path
.mnt
, &nd
->path
.dentry
))
246 spin_unlock(&sbi
->fs_lock
);
250 /* If an expire request is pending everyone must wait. */
251 spin_lock(&sbi
->fs_lock
);
252 if (ino
->flags
& AUTOFS_INF_EXPIRING
) {
253 spin_unlock(&sbi
->fs_lock
);
255 DPRINTK("waiting for active request %p name=%.*s",
256 dentry
, dentry
->d_name
.len
, dentry
->d_name
.name
);
258 status
= autofs4_wait(sbi
, dentry
, NFY_NONE
);
259 wait_for_completion(&ino
->expire_complete
);
261 DPRINTK("request done status=%d", status
);
265 spin_unlock(&sbi
->fs_lock
);
267 /* We trigger a mount for almost all flags */
268 lookup_type
= nd
->flags
& (TRIGGER_FLAGS
| TRIGGER_INTENTS
);
269 if (!(lookup_type
|| dentry
->d_flags
& DCACHE_AUTOFS_PENDING
))
273 * If the dentry contains directories then it is an autofs
274 * multi-mount with no root mount offset. So don't try to
277 spin_lock(&dcache_lock
);
278 if (dentry
->d_flags
& DCACHE_AUTOFS_PENDING
||
279 (!d_mountpoint(dentry
) && __simple_empty(dentry
))) {
280 spin_unlock(&dcache_lock
);
282 status
= try_to_fill_dentry(dentry
, 0);
288 spin_unlock(&dcache_lock
);
291 * If there is no root mount it must be an autofs
292 * multi-mount with no root offset so we don't need
295 if (d_mountpoint(dentry
)) {
296 if (!autofs4_follow_mount(&nd
->path
.mnt
,
308 return ERR_PTR(status
);
312 * Revalidate is called on every cache lookup. Some of those
313 * cache lookups may actually happen while the dentry is not
314 * yet completely filled in, and revalidate has to delay such
317 static int autofs4_revalidate(struct dentry
*dentry
, struct nameidata
*nd
)
319 struct inode
*dir
= dentry
->d_parent
->d_inode
;
320 struct autofs_sb_info
*sbi
= autofs4_sbi(dir
->i_sb
);
321 int oz_mode
= autofs4_oz_mode(sbi
);
322 int flags
= nd
? nd
->flags
: 0;
326 spin_lock(&sbi
->fs_lock
);
327 if (autofs4_ispending(dentry
)) {
328 /* The daemon never causes a mount to trigger */
329 spin_unlock(&sbi
->fs_lock
);
335 * A zero status is success otherwise we have a
336 * negative error code.
338 status
= try_to_fill_dentry(dentry
, flags
);
343 * A status of EAGAIN here means that the dentry has gone
344 * away while waiting for an expire to complete. If we are
345 * racing with expire lookup will wait for it so this must
346 * be a revalidate and we need to send it to lookup.
348 if (status
== -EAGAIN
)
353 spin_unlock(&sbi
->fs_lock
);
355 /* Negative dentry.. invalidate if "old" */
356 if (dentry
->d_inode
== NULL
)
359 /* Check for a non-mountpoint directory with no contents */
360 spin_lock(&dcache_lock
);
361 if (S_ISDIR(dentry
->d_inode
->i_mode
) &&
362 !d_mountpoint(dentry
) &&
363 __simple_empty(dentry
)) {
364 DPRINTK("dentry=%p %.*s, emptydir",
365 dentry
, dentry
->d_name
.len
, dentry
->d_name
.name
);
366 spin_unlock(&dcache_lock
);
368 /* The daemon never causes a mount to trigger */
373 * A zero status is success otherwise we have a
374 * negative error code.
376 status
= try_to_fill_dentry(dentry
, flags
);
382 spin_unlock(&dcache_lock
);
387 void autofs4_dentry_release(struct dentry
*de
)
389 struct autofs_info
*inf
;
391 DPRINTK("releasing %p", de
);
393 inf
= autofs4_dentry_ino(de
);
397 struct autofs_sb_info
*sbi
= autofs4_sbi(de
->d_sb
);
400 spin_lock(&sbi
->lookup_lock
);
401 if (!list_empty(&inf
->active
))
402 list_del(&inf
->active
);
403 if (!list_empty(&inf
->expiring
))
404 list_del(&inf
->expiring
);
405 spin_unlock(&sbi
->lookup_lock
);
411 autofs4_free_ino(inf
);
415 /* For dentries of directories in the root dir */
416 static struct dentry_operations autofs4_root_dentry_operations
= {
417 .d_revalidate
= autofs4_revalidate
,
418 .d_release
= autofs4_dentry_release
,
421 /* For other dentries */
422 static struct dentry_operations autofs4_dentry_operations
= {
423 .d_revalidate
= autofs4_revalidate
,
424 .d_release
= autofs4_dentry_release
,
427 static struct dentry
*autofs4_lookup_active(struct autofs_sb_info
*sbi
, struct dentry
*parent
, struct qstr
*name
)
429 unsigned int len
= name
->len
;
430 unsigned int hash
= name
->hash
;
431 const unsigned char *str
= name
->name
;
432 struct list_head
*p
, *head
;
434 spin_lock(&dcache_lock
);
435 spin_lock(&sbi
->lookup_lock
);
436 head
= &sbi
->active_list
;
437 list_for_each(p
, head
) {
438 struct autofs_info
*ino
;
439 struct dentry
*dentry
;
442 ino
= list_entry(p
, struct autofs_info
, active
);
443 dentry
= ino
->dentry
;
445 spin_lock(&dentry
->d_lock
);
448 if (atomic_read(&dentry
->d_count
) == 0)
451 qstr
= &dentry
->d_name
;
453 if (dentry
->d_name
.hash
!= hash
)
455 if (dentry
->d_parent
!= parent
)
458 if (qstr
->len
!= len
)
460 if (memcmp(qstr
->name
, str
, len
))
463 if (d_unhashed(dentry
)) {
465 spin_unlock(&dentry
->d_lock
);
466 spin_unlock(&sbi
->lookup_lock
);
467 spin_unlock(&dcache_lock
);
471 spin_unlock(&dentry
->d_lock
);
473 spin_unlock(&sbi
->lookup_lock
);
474 spin_unlock(&dcache_lock
);
479 static struct dentry
*autofs4_lookup_expiring(struct autofs_sb_info
*sbi
, struct dentry
*parent
, struct qstr
*name
)
481 unsigned int len
= name
->len
;
482 unsigned int hash
= name
->hash
;
483 const unsigned char *str
= name
->name
;
484 struct list_head
*p
, *head
;
486 spin_lock(&dcache_lock
);
487 spin_lock(&sbi
->lookup_lock
);
488 head
= &sbi
->expiring_list
;
489 list_for_each(p
, head
) {
490 struct autofs_info
*ino
;
491 struct dentry
*dentry
;
494 ino
= list_entry(p
, struct autofs_info
, expiring
);
495 dentry
= ino
->dentry
;
497 spin_lock(&dentry
->d_lock
);
499 /* Bad luck, we've already been dentry_iput */
500 if (!dentry
->d_inode
)
503 qstr
= &dentry
->d_name
;
505 if (dentry
->d_name
.hash
!= hash
)
507 if (dentry
->d_parent
!= parent
)
510 if (qstr
->len
!= len
)
512 if (memcmp(qstr
->name
, str
, len
))
515 if (d_unhashed(dentry
)) {
517 spin_unlock(&dentry
->d_lock
);
518 spin_unlock(&sbi
->lookup_lock
);
519 spin_unlock(&dcache_lock
);
523 spin_unlock(&dentry
->d_lock
);
525 spin_unlock(&sbi
->lookup_lock
);
526 spin_unlock(&dcache_lock
);
531 /* Lookups in the root directory */
532 static struct dentry
*autofs4_lookup(struct inode
*dir
, struct dentry
*dentry
, struct nameidata
*nd
)
534 struct autofs_sb_info
*sbi
;
535 struct autofs_info
*ino
;
536 struct dentry
*expiring
, *unhashed
;
539 DPRINTK("name = %.*s",
540 dentry
->d_name
.len
, dentry
->d_name
.name
);
542 /* File name too long to exist */
543 if (dentry
->d_name
.len
> NAME_MAX
)
544 return ERR_PTR(-ENAMETOOLONG
);
546 sbi
= autofs4_sbi(dir
->i_sb
);
547 oz_mode
= autofs4_oz_mode(sbi
);
549 DPRINTK("pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d",
550 current
->pid
, task_pgrp_nr(current
), sbi
->catatonic
, oz_mode
);
552 expiring
= autofs4_lookup_expiring(sbi
, dentry
->d_parent
, &dentry
->d_name
);
555 * If we are racing with expire the request might not
556 * be quite complete but the directory has been removed
557 * so it must have been successful, so just wait for it.
559 ino
= autofs4_dentry_ino(expiring
);
560 spin_lock(&sbi
->fs_lock
);
561 if (ino
->flags
& AUTOFS_INF_EXPIRING
) {
562 spin_unlock(&sbi
->fs_lock
);
563 DPRINTK("wait for incomplete expire %p name=%.*s",
564 expiring
, expiring
->d_name
.len
,
565 expiring
->d_name
.name
);
566 autofs4_wait(sbi
, expiring
, NFY_NONE
);
567 wait_for_completion(&ino
->expire_complete
);
568 DPRINTK("request completed");
571 spin_unlock(&sbi
->fs_lock
);
573 spin_lock(&sbi
->lookup_lock
);
574 if (!list_empty(&ino
->expiring
))
575 list_del_init(&ino
->expiring
);
576 spin_unlock(&sbi
->lookup_lock
);
580 unhashed
= autofs4_lookup_active(sbi
, dentry
->d_parent
, &dentry
->d_name
);
585 * Mark the dentry incomplete but don't hash it. We do this
586 * to serialize our inode creation operations (symlink and
587 * mkdir) which prevents deadlock during the callback to
588 * the daemon. Subsequent user space lookups for the same
589 * dentry are placed on the wait queue while the daemon
590 * itself is allowed passage unresticted so the create
591 * operation itself can then hash the dentry. Finally,
592 * we check for the hashed dentry and return the newly
595 dentry
->d_op
= &autofs4_root_dentry_operations
;
598 * And we need to ensure that the same dentry is used for
599 * all following lookup calls until it is hashed so that
600 * the dentry flags are persistent throughout the request.
602 ino
= autofs4_init_ino(NULL
, sbi
, 0555);
604 return ERR_PTR(-ENOMEM
);
606 dentry
->d_fsdata
= ino
;
607 ino
->dentry
= dentry
;
609 spin_lock(&sbi
->lookup_lock
);
610 list_add(&ino
->active
, &sbi
->active_list
);
611 spin_unlock(&sbi
->lookup_lock
);
613 d_instantiate(dentry
, NULL
);
617 spin_lock(&dentry
->d_lock
);
618 dentry
->d_flags
|= DCACHE_AUTOFS_PENDING
;
619 spin_unlock(&dentry
->d_lock
);
620 if (dentry
->d_op
&& dentry
->d_op
->d_revalidate
) {
621 mutex_unlock(&dir
->i_mutex
);
622 (dentry
->d_op
->d_revalidate
)(dentry
, nd
);
623 mutex_lock(&dir
->i_mutex
);
628 * If we are still pending, check if we had to handle
629 * a signal. If so we can force a restart..
631 if (dentry
->d_flags
& DCACHE_AUTOFS_PENDING
) {
632 /* See if we were interrupted */
633 if (signal_pending(current
)) {
634 sigset_t
*sigset
= ¤t
->pending
.signal
;
635 if (sigismember (sigset
, SIGKILL
) ||
636 sigismember (sigset
, SIGQUIT
) ||
637 sigismember (sigset
, SIGINT
)) {
640 return ERR_PTR(-ERESTARTNOINTR
);
644 spin_lock(&dentry
->d_lock
);
645 dentry
->d_flags
&= ~DCACHE_AUTOFS_PENDING
;
646 spin_unlock(&dentry
->d_lock
);
651 * If this dentry is unhashed, then we shouldn't honour this
652 * lookup. Returning ENOENT here doesn't do the right thing
653 * for all system calls, but it should be OK for the operations
654 * we permit from an autofs.
656 if (!oz_mode
&& d_unhashed(dentry
)) {
658 * A user space application can (and has done in the past)
659 * remove and re-create this directory during the callback.
660 * This can leave us with an unhashed dentry, but a
661 * successful mount! So we need to perform another
662 * cached lookup in case the dentry now exists.
664 struct dentry
*parent
= dentry
->d_parent
;
665 struct dentry
*new = d_lookup(parent
, &dentry
->d_name
);
669 dentry
= ERR_PTR(-ENOENT
);
683 static int autofs4_dir_symlink(struct inode
*dir
,
684 struct dentry
*dentry
,
687 struct autofs_sb_info
*sbi
= autofs4_sbi(dir
->i_sb
);
688 struct autofs_info
*ino
= autofs4_dentry_ino(dentry
);
689 struct autofs_info
*p_ino
;
693 DPRINTK("%s <- %.*s", symname
,
694 dentry
->d_name
.len
, dentry
->d_name
.name
);
696 if (!autofs4_oz_mode(sbi
))
699 ino
= autofs4_init_ino(ino
, sbi
, S_IFLNK
| 0555);
703 spin_lock(&sbi
->lookup_lock
);
704 if (!list_empty(&ino
->active
))
705 list_del_init(&ino
->active
);
706 spin_unlock(&sbi
->lookup_lock
);
708 ino
->size
= strlen(symname
);
709 cp
= kmalloc(ino
->size
+ 1, GFP_KERNEL
);
711 if (!dentry
->d_fsdata
)
718 inode
= autofs4_get_inode(dir
->i_sb
, ino
);
721 if (!dentry
->d_fsdata
)
725 d_add(dentry
, inode
);
727 if (dir
== dir
->i_sb
->s_root
->d_inode
)
728 dentry
->d_op
= &autofs4_root_dentry_operations
;
730 dentry
->d_op
= &autofs4_dentry_operations
;
732 dentry
->d_fsdata
= ino
;
733 ino
->dentry
= dget(dentry
);
734 atomic_inc(&ino
->count
);
735 p_ino
= autofs4_dentry_ino(dentry
->d_parent
);
736 if (p_ino
&& dentry
->d_parent
!= dentry
)
737 atomic_inc(&p_ino
->count
);
741 dir
->i_mtime
= CURRENT_TIME
;
749 * Normal filesystems would do a "d_delete()" to tell the VFS dcache
750 * that the file no longer exists. However, doing that means that the
751 * VFS layer can turn the dentry into a negative dentry. We don't want
752 * this, because the unlink is probably the result of an expire.
753 * We simply d_drop it and add it to a expiring list in the super block,
754 * which allows the dentry lookup to check for an incomplete expire.
756 * If a process is blocked on the dentry waiting for the expire to finish,
757 * it will invalidate the dentry and try to mount with a new one.
759 * Also see autofs4_dir_rmdir()..
761 static int autofs4_dir_unlink(struct inode
*dir
, struct dentry
*dentry
)
763 struct autofs_sb_info
*sbi
= autofs4_sbi(dir
->i_sb
);
764 struct autofs_info
*ino
= autofs4_dentry_ino(dentry
);
765 struct autofs_info
*p_ino
;
767 /* This allows root to remove symlinks */
768 if (!autofs4_oz_mode(sbi
) && !capable(CAP_SYS_ADMIN
))
771 if (atomic_dec_and_test(&ino
->count
)) {
772 p_ino
= autofs4_dentry_ino(dentry
->d_parent
);
773 if (p_ino
&& dentry
->d_parent
!= dentry
)
774 atomic_dec(&p_ino
->count
);
778 dentry
->d_inode
->i_size
= 0;
779 clear_nlink(dentry
->d_inode
);
781 dir
->i_mtime
= CURRENT_TIME
;
783 spin_lock(&dcache_lock
);
784 spin_lock(&sbi
->lookup_lock
);
785 if (list_empty(&ino
->expiring
))
786 list_add(&ino
->expiring
, &sbi
->expiring_list
);
787 spin_unlock(&sbi
->lookup_lock
);
788 spin_lock(&dentry
->d_lock
);
790 spin_unlock(&dentry
->d_lock
);
791 spin_unlock(&dcache_lock
);
796 static int autofs4_dir_rmdir(struct inode
*dir
, struct dentry
*dentry
)
798 struct autofs_sb_info
*sbi
= autofs4_sbi(dir
->i_sb
);
799 struct autofs_info
*ino
= autofs4_dentry_ino(dentry
);
800 struct autofs_info
*p_ino
;
802 DPRINTK("dentry %p, removing %.*s",
803 dentry
, dentry
->d_name
.len
, dentry
->d_name
.name
);
805 if (!autofs4_oz_mode(sbi
))
808 spin_lock(&dcache_lock
);
809 if (!list_empty(&dentry
->d_subdirs
)) {
810 spin_unlock(&dcache_lock
);
813 spin_lock(&sbi
->lookup_lock
);
814 if (list_empty(&ino
->expiring
))
815 list_add(&ino
->expiring
, &sbi
->expiring_list
);
816 spin_unlock(&sbi
->lookup_lock
);
817 spin_lock(&dentry
->d_lock
);
819 spin_unlock(&dentry
->d_lock
);
820 spin_unlock(&dcache_lock
);
822 if (atomic_dec_and_test(&ino
->count
)) {
823 p_ino
= autofs4_dentry_ino(dentry
->d_parent
);
824 if (p_ino
&& dentry
->d_parent
!= dentry
)
825 atomic_dec(&p_ino
->count
);
828 dentry
->d_inode
->i_size
= 0;
829 clear_nlink(dentry
->d_inode
);
837 static int autofs4_dir_mkdir(struct inode
*dir
, struct dentry
*dentry
, int mode
)
839 struct autofs_sb_info
*sbi
= autofs4_sbi(dir
->i_sb
);
840 struct autofs_info
*ino
= autofs4_dentry_ino(dentry
);
841 struct autofs_info
*p_ino
;
844 if (!autofs4_oz_mode(sbi
))
847 DPRINTK("dentry %p, creating %.*s",
848 dentry
, dentry
->d_name
.len
, dentry
->d_name
.name
);
850 ino
= autofs4_init_ino(ino
, sbi
, S_IFDIR
| 0555);
854 spin_lock(&sbi
->lookup_lock
);
855 if (!list_empty(&ino
->active
))
856 list_del_init(&ino
->active
);
857 spin_unlock(&sbi
->lookup_lock
);
859 inode
= autofs4_get_inode(dir
->i_sb
, ino
);
861 if (!dentry
->d_fsdata
)
865 d_add(dentry
, inode
);
867 if (dir
== dir
->i_sb
->s_root
->d_inode
)
868 dentry
->d_op
= &autofs4_root_dentry_operations
;
870 dentry
->d_op
= &autofs4_dentry_operations
;
872 dentry
->d_fsdata
= ino
;
873 ino
->dentry
= dget(dentry
);
874 atomic_inc(&ino
->count
);
875 p_ino
= autofs4_dentry_ino(dentry
->d_parent
);
876 if (p_ino
&& dentry
->d_parent
!= dentry
)
877 atomic_inc(&p_ino
->count
);
880 dir
->i_mtime
= CURRENT_TIME
;
885 /* Get/set timeout ioctl() operation */
886 static inline int autofs4_get_set_timeout(struct autofs_sb_info
*sbi
,
887 unsigned long __user
*p
)
890 unsigned long ntimeout
;
892 if ((rv
= get_user(ntimeout
, p
)) ||
893 (rv
= put_user(sbi
->exp_timeout
/HZ
, p
)))
896 if (ntimeout
> ULONG_MAX
/HZ
)
897 sbi
->exp_timeout
= 0;
899 sbi
->exp_timeout
= ntimeout
* HZ
;
904 /* Return protocol version */
905 static inline int autofs4_get_protover(struct autofs_sb_info
*sbi
, int __user
*p
)
907 return put_user(sbi
->version
, p
);
910 /* Return protocol sub version */
911 static inline int autofs4_get_protosubver(struct autofs_sb_info
*sbi
, int __user
*p
)
913 return put_user(sbi
->sub_version
, p
);
917 * Tells the daemon whether we need to reghost or not. Also, clears
918 * the reghost_needed flag.
920 static inline int autofs4_ask_reghost(struct autofs_sb_info
*sbi
, int __user
*p
)
924 DPRINTK("returning %d", sbi
->needs_reghost
);
926 status
= put_user(sbi
->needs_reghost
, p
);
930 sbi
->needs_reghost
= 0;
935 * Enable / Disable reghosting ioctl() operation
937 static inline int autofs4_toggle_reghost(struct autofs_sb_info
*sbi
, int __user
*p
)
942 status
= get_user(val
, p
);
944 DPRINTK("reghost = %d", val
);
949 /* turn on/off reghosting, with the val */
950 sbi
->reghost_enabled
= val
;
955 * Tells the daemon whether it can umount the autofs mount.
957 static inline int autofs4_ask_umount(struct vfsmount
*mnt
, int __user
*p
)
964 DPRINTK("returning %d", status
);
966 status
= put_user(status
, p
);
971 /* Identify autofs4_dentries - this is so we can tell if there's
972 an extra dentry refcount or not. We only hold a refcount on the
973 dentry if its non-negative (ie, d_inode != NULL)
975 int is_autofs4_dentry(struct dentry
*dentry
)
977 return dentry
&& dentry
->d_inode
&&
978 (dentry
->d_op
== &autofs4_root_dentry_operations
||
979 dentry
->d_op
== &autofs4_dentry_operations
) &&
980 dentry
->d_fsdata
!= NULL
;
984 * ioctl()'s on the root directory is the chief method for the daemon to
985 * generate kernel reactions
987 static int autofs4_root_ioctl(struct inode
*inode
, struct file
*filp
,
988 unsigned int cmd
, unsigned long arg
)
990 struct autofs_sb_info
*sbi
= autofs4_sbi(inode
->i_sb
);
991 void __user
*p
= (void __user
*)arg
;
993 DPRINTK("cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u",
994 cmd
,arg
,sbi
,task_pgrp_nr(current
));
996 if (_IOC_TYPE(cmd
) != _IOC_TYPE(AUTOFS_IOC_FIRST
) ||
997 _IOC_NR(cmd
) - _IOC_NR(AUTOFS_IOC_FIRST
) >= AUTOFS_IOC_COUNT
)
1000 if (!autofs4_oz_mode(sbi
) && !capable(CAP_SYS_ADMIN
))
1004 case AUTOFS_IOC_READY
: /* Wait queue: go ahead and retry */
1005 return autofs4_wait_release(sbi
,(autofs_wqt_t
)arg
,0);
1006 case AUTOFS_IOC_FAIL
: /* Wait queue: fail with ENOENT */
1007 return autofs4_wait_release(sbi
,(autofs_wqt_t
)arg
,-ENOENT
);
1008 case AUTOFS_IOC_CATATONIC
: /* Enter catatonic mode (daemon shutdown) */
1009 autofs4_catatonic_mode(sbi
);
1011 case AUTOFS_IOC_PROTOVER
: /* Get protocol version */
1012 return autofs4_get_protover(sbi
, p
);
1013 case AUTOFS_IOC_PROTOSUBVER
: /* Get protocol sub version */
1014 return autofs4_get_protosubver(sbi
, p
);
1015 case AUTOFS_IOC_SETTIMEOUT
:
1016 return autofs4_get_set_timeout(sbi
, p
);
1018 case AUTOFS_IOC_TOGGLEREGHOST
:
1019 return autofs4_toggle_reghost(sbi
, p
);
1020 case AUTOFS_IOC_ASKREGHOST
:
1021 return autofs4_ask_reghost(sbi
, p
);
1023 case AUTOFS_IOC_ASKUMOUNT
:
1024 return autofs4_ask_umount(filp
->f_path
.mnt
, p
);
1026 /* return a single thing to expire */
1027 case AUTOFS_IOC_EXPIRE
:
1028 return autofs4_expire_run(inode
->i_sb
,filp
->f_path
.mnt
,sbi
, p
);
1029 /* same as above, but can send multiple expires through pipe */
1030 case AUTOFS_IOC_EXPIRE_MULTI
:
1031 return autofs4_expire_multi(inode
->i_sb
,filp
->f_path
.mnt
,sbi
, p
);