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/slab.h>
19 #include <linux/param.h>
20 #include <linux/time.h>
21 #include <linux/compat.h>
22 #include <linux/mutex.h>
26 DEFINE_SPINLOCK(autofs4_lock);
28 static int autofs4_dir_symlink(struct inode *,struct dentry *,const char *);
29 static int autofs4_dir_unlink(struct inode *,struct dentry *);
30 static int autofs4_dir_rmdir(struct inode *,struct dentry *);
31 static int autofs4_dir_mkdir(struct inode *,struct dentry *,int);
32 static long autofs4_root_ioctl(struct file *,unsigned int,unsigned long);
34 static long autofs4_root_compat_ioctl(struct file *,unsigned int,unsigned long);
36 static int autofs4_dir_open(struct inode *inode, struct file *file);
37 static struct dentry *autofs4_lookup(struct inode *,struct dentry *, struct nameidata *);
39 #define TRIGGER_FLAGS (LOOKUP_CONTINUE | LOOKUP_DIRECTORY)
40 #define TRIGGER_INTENTS (LOOKUP_OPEN | LOOKUP_CREATE)
42 const struct file_operations autofs4_root_operations = {
43 .open = dcache_dir_open,
44 .release = dcache_dir_close,
45 .read = generic_read_dir,
46 .readdir = dcache_readdir,
47 .llseek = dcache_dir_lseek,
48 .unlocked_ioctl = autofs4_root_ioctl,
50 .compat_ioctl = autofs4_root_compat_ioctl,
54 const struct file_operations autofs4_dir_operations = {
55 .open = autofs4_dir_open,
56 .release = dcache_dir_close,
57 .read = generic_read_dir,
58 .readdir = dcache_readdir,
59 .llseek = dcache_dir_lseek,
62 const struct inode_operations autofs4_indirect_root_inode_operations = {
63 .lookup = autofs4_lookup,
64 .unlink = autofs4_dir_unlink,
65 .symlink = autofs4_dir_symlink,
66 .mkdir = autofs4_dir_mkdir,
67 .rmdir = autofs4_dir_rmdir,
70 const struct inode_operations autofs4_direct_root_inode_operations = {
71 .lookup = autofs4_lookup,
72 .unlink = autofs4_dir_unlink,
73 .mkdir = autofs4_dir_mkdir,
74 .rmdir = autofs4_dir_rmdir,
77 const struct inode_operations autofs4_dir_inode_operations = {
78 .lookup = autofs4_lookup,
79 .unlink = autofs4_dir_unlink,
80 .symlink = autofs4_dir_symlink,
81 .mkdir = autofs4_dir_mkdir,
82 .rmdir = autofs4_dir_rmdir,
85 static void autofs4_add_active(struct dentry *dentry)
87 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
88 struct autofs_info *ino = autofs4_dentry_ino(dentry);
90 spin_lock(&sbi->lookup_lock);
91 if (!ino->active_count) {
92 if (list_empty(&ino->active))
93 list_add(&ino->active, &sbi->active_list);
96 spin_unlock(&sbi->lookup_lock);
101 static void autofs4_del_active(struct dentry *dentry)
103 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
104 struct autofs_info *ino = autofs4_dentry_ino(dentry);
106 spin_lock(&sbi->lookup_lock);
108 if (!ino->active_count) {
109 if (!list_empty(&ino->active))
110 list_del_init(&ino->active);
112 spin_unlock(&sbi->lookup_lock);
117 static unsigned int autofs4_need_mount(unsigned int flags)
119 unsigned int res = 0;
120 if (flags & (TRIGGER_FLAGS | TRIGGER_INTENTS))
125 static int autofs4_dir_open(struct inode *inode, struct file *file)
127 struct dentry *dentry = file->f_path.dentry;
128 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
130 DPRINTK("file=%p dentry=%p %.*s",
131 file, dentry, dentry->d_name.len, dentry->d_name.name);
133 if (autofs4_oz_mode(sbi))
137 * An empty directory in an autofs file system is always a
138 * mount point. The daemon must have failed to mount this
139 * during lookup so it doesn't exist. This can happen, for
140 * example, if user space returns an incorrect status for a
141 * mount request. Otherwise we're doing a readdir on the
142 * autofs file system so just let the libfs routines handle
145 spin_lock(&autofs4_lock);
146 spin_lock(&dentry->d_lock);
147 if (!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs)) {
148 spin_unlock(&dentry->d_lock);
149 spin_unlock(&autofs4_lock);
152 spin_unlock(&dentry->d_lock);
153 spin_unlock(&autofs4_lock);
156 return dcache_dir_open(inode, file);
159 static int try_to_fill_dentry(struct dentry *dentry, int flags)
161 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
162 struct autofs_info *ino = autofs4_dentry_ino(dentry);
165 DPRINTK("dentry=%p %.*s ino=%p",
166 dentry, dentry->d_name.len, dentry->d_name.name, dentry->d_inode);
169 * Wait for a pending mount, triggering one if there
172 if (dentry->d_inode == NULL) {
173 DPRINTK("waiting for mount name=%.*s",
174 dentry->d_name.len, dentry->d_name.name);
176 status = autofs4_wait(sbi, dentry, NFY_MOUNT);
178 DPRINTK("mount done status=%d", status);
180 /* Turn this into a real negative dentry? */
181 if (status == -ENOENT) {
182 spin_lock(&sbi->fs_lock);
183 ino->flags &= ~AUTOFS_INF_PENDING;
184 spin_unlock(&sbi->fs_lock);
187 /* Return a negative dentry, but leave it "pending" */
190 /* Trigger mount for path component or follow link */
191 } else if (ino->flags & AUTOFS_INF_PENDING ||
192 autofs4_need_mount(flags)) {
193 DPRINTK("waiting for mount name=%.*s",
194 dentry->d_name.len, dentry->d_name.name);
196 spin_lock(&sbi->fs_lock);
197 ino->flags |= AUTOFS_INF_PENDING;
198 spin_unlock(&sbi->fs_lock);
199 status = autofs4_wait(sbi, dentry, NFY_MOUNT);
201 DPRINTK("mount done status=%d", status);
204 spin_lock(&sbi->fs_lock);
205 ino->flags &= ~AUTOFS_INF_PENDING;
206 spin_unlock(&sbi->fs_lock);
211 /* Initialize expiry counter after successful mount */
212 ino->last_used = jiffies;
214 spin_lock(&sbi->fs_lock);
215 ino->flags &= ~AUTOFS_INF_PENDING;
216 spin_unlock(&sbi->fs_lock);
221 /* For autofs direct mounts the follow link triggers the mount */
222 static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd)
224 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
225 struct autofs_info *ino = autofs4_dentry_ino(dentry);
226 int oz_mode = autofs4_oz_mode(sbi);
227 unsigned int lookup_type;
230 DPRINTK("dentry=%p %.*s oz_mode=%d nd->flags=%d",
231 dentry, dentry->d_name.len, dentry->d_name.name, oz_mode,
234 * For an expire of a covered direct or offset mount we need
235 * to break out of follow_down_one() at the autofs mount trigger
236 * (d_mounted--), so we can see the expiring flag, and manage
237 * the blocking and following here until the expire is completed.
240 spin_lock(&sbi->fs_lock);
241 if (ino->flags & AUTOFS_INF_EXPIRING) {
242 spin_unlock(&sbi->fs_lock);
243 /* Follow down to our covering mount. */
244 if (!follow_down_one(&nd->path))
248 spin_unlock(&sbi->fs_lock);
252 /* If an expire request is pending everyone must wait. */
253 autofs4_expire_wait(dentry);
255 /* We trigger a mount for almost all flags */
256 lookup_type = autofs4_need_mount(nd->flags);
257 spin_lock(&sbi->fs_lock);
258 spin_lock(&autofs4_lock);
259 spin_lock(&dentry->d_lock);
260 if (!(lookup_type || ino->flags & AUTOFS_INF_PENDING)) {
261 spin_unlock(&dentry->d_lock);
262 spin_unlock(&autofs4_lock);
263 spin_unlock(&sbi->fs_lock);
268 * If the dentry contains directories then it is an autofs
269 * multi-mount with no root mount offset. So don't try to
272 if (ino->flags & AUTOFS_INF_PENDING ||
273 (!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs))) {
274 spin_unlock(&dentry->d_lock);
275 spin_unlock(&autofs4_lock);
276 spin_unlock(&sbi->fs_lock);
278 status = try_to_fill_dentry(dentry, nd->flags);
284 spin_unlock(&dentry->d_lock);
285 spin_unlock(&autofs4_lock);
286 spin_unlock(&sbi->fs_lock);
289 * If there is no root mount it must be an autofs
290 * multi-mount with no root offset so we don't need
293 if (d_managed(dentry)) {
294 status = follow_down(&nd->path, false);
304 return ERR_PTR(status);
308 * Revalidate is called on every cache lookup. Some of those
309 * cache lookups may actually happen while the dentry is not
310 * yet completely filled in, and revalidate has to delay such
313 static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd)
316 struct autofs_sb_info *sbi;
318 int flags = nd ? nd->flags : 0;
321 if (flags & LOOKUP_RCU)
324 dir = dentry->d_parent->d_inode;
325 sbi = autofs4_sbi(dir->i_sb);
326 oz_mode = autofs4_oz_mode(sbi);
329 spin_lock(&sbi->fs_lock);
330 if (autofs4_ispending(dentry)) {
331 /* The daemon never causes a mount to trigger */
332 spin_unlock(&sbi->fs_lock);
338 * If the directory has gone away due to an expire
339 * we have been called as ->d_revalidate() and so
340 * we need to return false and proceed to ->lookup().
342 if (autofs4_expire_wait(dentry) == -EAGAIN)
346 * A zero status is success otherwise we have a
347 * negative error code.
349 status = try_to_fill_dentry(dentry, flags);
355 spin_unlock(&sbi->fs_lock);
357 /* Negative dentry.. invalidate if "old" */
358 if (dentry->d_inode == NULL)
361 /* Check for a non-mountpoint directory with no contents */
362 spin_lock(&autofs4_lock);
363 spin_lock(&dentry->d_lock);
364 if (S_ISDIR(dentry->d_inode->i_mode) &&
365 !d_mountpoint(dentry) && list_empty(&dentry->d_subdirs)) {
366 DPRINTK("dentry=%p %.*s, emptydir",
367 dentry, dentry->d_name.len, dentry->d_name.name);
368 spin_unlock(&dentry->d_lock);
369 spin_unlock(&autofs4_lock);
371 /* The daemon never causes a mount to trigger */
376 * A zero status is success otherwise we have a
377 * negative error code.
379 status = try_to_fill_dentry(dentry, flags);
385 spin_unlock(&dentry->d_lock);
386 spin_unlock(&autofs4_lock);
391 void autofs4_dentry_release(struct dentry *de)
393 struct autofs_info *inf;
395 DPRINTK("releasing %p", de);
397 inf = autofs4_dentry_ino(de);
401 struct autofs_sb_info *sbi = autofs4_sbi(de->d_sb);
404 spin_lock(&sbi->lookup_lock);
405 if (!list_empty(&inf->active))
406 list_del(&inf->active);
407 if (!list_empty(&inf->expiring))
408 list_del(&inf->expiring);
409 spin_unlock(&sbi->lookup_lock);
415 autofs4_free_ino(inf);
419 /* For dentries of directories in the root dir */
420 static const struct dentry_operations autofs4_root_dentry_operations = {
421 .d_release = autofs4_dentry_release,
424 /* For other dentries */
425 static const struct dentry_operations autofs4_dentry_operations = {
426 .d_automount = autofs4_d_automount,
427 .d_release = autofs4_dentry_release,
430 static struct dentry *autofs4_lookup_active(struct dentry *dentry)
432 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
433 struct dentry *parent = dentry->d_parent;
434 struct qstr *name = &dentry->d_name;
435 unsigned int len = name->len;
436 unsigned int hash = name->hash;
437 const unsigned char *str = name->name;
438 struct list_head *p, *head;
440 spin_lock(&autofs4_lock);
441 spin_lock(&sbi->lookup_lock);
442 head = &sbi->active_list;
443 list_for_each(p, head) {
444 struct autofs_info *ino;
445 struct dentry *active;
448 ino = list_entry(p, struct autofs_info, active);
449 active = ino->dentry;
451 spin_lock(&active->d_lock);
454 if (active->d_count == 0)
457 qstr = &active->d_name;
459 if (active->d_name.hash != hash)
461 if (active->d_parent != parent)
464 if (qstr->len != len)
466 if (memcmp(qstr->name, str, len))
469 if (d_unhashed(active)) {
471 spin_unlock(&active->d_lock);
472 spin_unlock(&sbi->lookup_lock);
473 spin_unlock(&autofs4_lock);
477 spin_unlock(&active->d_lock);
479 spin_unlock(&sbi->lookup_lock);
480 spin_unlock(&autofs4_lock);
485 static struct dentry *autofs4_lookup_expiring(struct dentry *dentry)
487 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
488 struct dentry *parent = dentry->d_parent;
489 struct qstr *name = &dentry->d_name;
490 unsigned int len = name->len;
491 unsigned int hash = name->hash;
492 const unsigned char *str = name->name;
493 struct list_head *p, *head;
495 spin_lock(&autofs4_lock);
496 spin_lock(&sbi->lookup_lock);
497 head = &sbi->expiring_list;
498 list_for_each(p, head) {
499 struct autofs_info *ino;
500 struct dentry *expiring;
503 ino = list_entry(p, struct autofs_info, expiring);
504 expiring = ino->dentry;
506 spin_lock(&expiring->d_lock);
508 /* Bad luck, we've already been dentry_iput */
509 if (!expiring->d_inode)
512 qstr = &expiring->d_name;
514 if (expiring->d_name.hash != hash)
516 if (expiring->d_parent != parent)
519 if (qstr->len != len)
521 if (memcmp(qstr->name, str, len))
524 if (d_unhashed(expiring)) {
525 dget_dlock(expiring);
526 spin_unlock(&expiring->d_lock);
527 spin_unlock(&sbi->lookup_lock);
528 spin_unlock(&autofs4_lock);
532 spin_unlock(&expiring->d_lock);
534 spin_unlock(&sbi->lookup_lock);
535 spin_unlock(&autofs4_lock);
540 static int autofs4_mount_wait(struct dentry *dentry)
542 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
543 struct autofs_info *ino = autofs4_dentry_ino(dentry);
546 if (ino->flags & AUTOFS_INF_PENDING) {
547 DPRINTK("waiting for mount name=%.*s",
548 dentry->d_name.len, dentry->d_name.name);
549 status = autofs4_wait(sbi, dentry, NFY_MOUNT);
550 DPRINTK("mount wait done status=%d", status);
551 ino->last_used = jiffies;
557 static int do_expire_wait(struct dentry *dentry)
559 struct dentry *expiring;
561 expiring = autofs4_lookup_expiring(dentry);
563 return autofs4_expire_wait(dentry);
566 * If we are racing with expire the request might not
567 * be quite complete, but the directory has been removed
568 * so it must have been successful, just wait for it.
570 autofs4_expire_wait(expiring);
571 autofs4_del_expiring(expiring);
577 static struct dentry *autofs4_mountpoint_changed(struct path *path)
579 struct dentry *dentry = path->dentry;
580 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
583 * If this is an indirect mount the dentry could have gone away
584 * as a result of an expire and a new one created.
586 if (autofs_type_indirect(sbi->type) && d_unhashed(dentry)) {
587 struct dentry *parent = dentry->d_parent;
588 struct dentry *new = d_lookup(parent, &dentry->d_name);
597 struct vfsmount *autofs4_d_automount(struct path *path)
599 struct dentry *dentry = path->dentry;
600 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
601 struct autofs_info *ino = autofs4_dentry_ino(dentry);
604 DPRINTK("dentry=%p %.*s",
605 dentry, dentry->d_name.len, dentry->d_name.name);
607 /* The daemon never triggers a mount. */
608 if (autofs4_oz_mode(sbi))
612 * If an expire request is pending everyone must wait.
613 * If the expire fails we're still mounted so continue
614 * the follow and return. A return of -EAGAIN (which only
615 * happens with indirect mounts) means the expire completed
616 * and the directory was removed, so just go ahead and try
619 status = do_expire_wait(dentry);
620 if (status && status != -EAGAIN)
623 /* Callback to the daemon to perform the mount or wait */
624 spin_lock(&sbi->fs_lock);
625 if (ino->flags & AUTOFS_INF_PENDING) {
626 spin_unlock(&sbi->fs_lock);
627 status = autofs4_mount_wait(dentry);
629 return ERR_PTR(status);
630 spin_lock(&sbi->fs_lock);
635 * If the dentry is a symlink it's equivalent to a directory
636 * having d_mounted() true, so there's no need to call back
639 if (dentry->d_inode && S_ISLNK(dentry->d_inode->i_mode))
641 spin_lock(&dentry->d_lock);
642 if (!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs)) {
643 ino->flags |= AUTOFS_INF_PENDING;
644 spin_unlock(&dentry->d_lock);
645 spin_unlock(&sbi->fs_lock);
646 status = autofs4_mount_wait(dentry);
648 return ERR_PTR(status);
649 spin_lock(&sbi->fs_lock);
650 ino->flags &= ~AUTOFS_INF_PENDING;
653 spin_unlock(&dentry->d_lock);
656 * Any needed mounting has been completed and the path updated
657 * so turn this into a normal dentry so we don't continually
658 * call ->d_automount().
660 managed_dentry_clear_automount(dentry);
661 spin_unlock(&sbi->fs_lock);
663 /* Mount succeeded, check if we ended up with a new dentry */
664 dentry = autofs4_mountpoint_changed(path);
666 return ERR_PTR(-ENOENT);
671 /* Lookups in the root directory */
672 static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
674 struct autofs_sb_info *sbi;
675 struct autofs_info *ino;
676 struct dentry *active;
678 DPRINTK("name = %.*s", dentry->d_name.len, dentry->d_name.name);
680 /* File name too long to exist */
681 if (dentry->d_name.len > NAME_MAX)
682 return ERR_PTR(-ENAMETOOLONG);
684 sbi = autofs4_sbi(dir->i_sb);
686 DPRINTK("pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d",
687 current->pid, task_pgrp_nr(current), sbi->catatonic, oz_mode);
689 active = autofs4_lookup_active(dentry);
693 d_set_d_op(dentry, &autofs4_root_dentry_operations);
696 * A dentry that is not within the root can never trigger a
697 * mount operation, unless the directory already exists, so we
698 * can return fail immediately. The daemon however does need
699 * to create directories within the file system.
701 if (!autofs4_oz_mode(sbi) && !IS_ROOT(dentry->d_parent))
702 return ERR_PTR(-ENOENT);
704 /* Mark entries in the root as mount triggers */
705 if (autofs_type_indirect(sbi->type) && IS_ROOT(dentry->d_parent)) {
706 d_set_d_op(dentry, &autofs4_dentry_operations);
707 managed_dentry_set_automount(dentry);
710 ino = autofs4_init_ino(NULL, sbi, 0555);
712 return ERR_PTR(-ENOMEM);
714 dentry->d_fsdata = ino;
715 ino->dentry = dentry;
717 autofs4_add_active(dentry);
719 d_instantiate(dentry, NULL);
724 static int autofs4_dir_symlink(struct inode *dir,
725 struct dentry *dentry,
728 struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
729 struct autofs_info *ino = autofs4_dentry_ino(dentry);
730 struct autofs_info *p_ino;
734 DPRINTK("%s <- %.*s", symname,
735 dentry->d_name.len, dentry->d_name.name);
737 if (!autofs4_oz_mode(sbi))
740 ino = autofs4_init_ino(ino, sbi, S_IFLNK | 0555);
744 autofs4_del_active(dentry);
746 ino->size = strlen(symname);
747 cp = kmalloc(ino->size + 1, GFP_KERNEL);
749 if (!dentry->d_fsdata)
756 inode = autofs4_get_inode(dir->i_sb, ino);
759 if (!dentry->d_fsdata)
763 d_add(dentry, inode);
765 dentry->d_fsdata = ino;
766 ino->dentry = dget(dentry);
767 atomic_inc(&ino->count);
768 p_ino = autofs4_dentry_ino(dentry->d_parent);
769 if (p_ino && dentry->d_parent != dentry)
770 atomic_inc(&p_ino->count);
774 dir->i_mtime = CURRENT_TIME;
782 * Normal filesystems would do a "d_delete()" to tell the VFS dcache
783 * that the file no longer exists. However, doing that means that the
784 * VFS layer can turn the dentry into a negative dentry. We don't want
785 * this, because the unlink is probably the result of an expire.
786 * We simply d_drop it and add it to a expiring list in the super block,
787 * which allows the dentry lookup to check for an incomplete expire.
789 * If a process is blocked on the dentry waiting for the expire to finish,
790 * it will invalidate the dentry and try to mount with a new one.
792 * Also see autofs4_dir_rmdir()..
794 static int autofs4_dir_unlink(struct inode *dir, struct dentry *dentry)
796 struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
797 struct autofs_info *ino = autofs4_dentry_ino(dentry);
798 struct autofs_info *p_ino;
800 /* This allows root to remove symlinks */
801 if (!autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN))
804 if (atomic_dec_and_test(&ino->count)) {
805 p_ino = autofs4_dentry_ino(dentry->d_parent);
806 if (p_ino && dentry->d_parent != dentry)
807 atomic_dec(&p_ino->count);
811 dentry->d_inode->i_size = 0;
812 clear_nlink(dentry->d_inode);
814 dir->i_mtime = CURRENT_TIME;
816 spin_lock(&autofs4_lock);
817 autofs4_add_expiring(dentry);
818 spin_lock(&dentry->d_lock);
820 spin_unlock(&dentry->d_lock);
821 spin_unlock(&autofs4_lock);
826 static int autofs4_dir_rmdir(struct inode *dir, struct dentry *dentry)
828 struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
829 struct autofs_info *ino = autofs4_dentry_ino(dentry);
830 struct autofs_info *p_ino;
832 DPRINTK("dentry %p, removing %.*s",
833 dentry, dentry->d_name.len, dentry->d_name.name);
835 if (!autofs4_oz_mode(sbi))
838 spin_lock(&autofs4_lock);
839 spin_lock(&sbi->lookup_lock);
840 spin_lock(&dentry->d_lock);
841 if (!list_empty(&dentry->d_subdirs)) {
842 spin_unlock(&dentry->d_lock);
843 spin_unlock(&sbi->lookup_lock);
844 spin_unlock(&autofs4_lock);
847 __autofs4_add_expiring(dentry);
848 spin_unlock(&sbi->lookup_lock);
850 spin_unlock(&dentry->d_lock);
851 spin_unlock(&autofs4_lock);
853 if (atomic_dec_and_test(&ino->count)) {
854 p_ino = autofs4_dentry_ino(dentry->d_parent);
855 if (p_ino && dentry->d_parent != dentry)
856 atomic_dec(&p_ino->count);
859 dentry->d_inode->i_size = 0;
860 clear_nlink(dentry->d_inode);
868 static int autofs4_dir_mkdir(struct inode *dir, struct dentry *dentry, int mode)
870 struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
871 struct autofs_info *ino = autofs4_dentry_ino(dentry);
872 struct autofs_info *p_ino;
875 if (!autofs4_oz_mode(sbi))
878 DPRINTK("dentry %p, creating %.*s",
879 dentry, dentry->d_name.len, dentry->d_name.name);
881 ino = autofs4_init_ino(ino, sbi, S_IFDIR | 0555);
885 autofs4_del_active(dentry);
887 inode = autofs4_get_inode(dir->i_sb, ino);
889 if (!dentry->d_fsdata)
893 d_add(dentry, inode);
895 dentry->d_fsdata = ino;
896 ino->dentry = dget(dentry);
897 atomic_inc(&ino->count);
898 p_ino = autofs4_dentry_ino(dentry->d_parent);
899 if (p_ino && dentry->d_parent != dentry)
900 atomic_inc(&p_ino->count);
903 dir->i_mtime = CURRENT_TIME;
908 /* Get/set timeout ioctl() operation */
910 static inline int autofs4_compat_get_set_timeout(struct autofs_sb_info *sbi,
911 compat_ulong_t __user *p)
914 unsigned long ntimeout;
916 if ((rv = get_user(ntimeout, p)) ||
917 (rv = put_user(sbi->exp_timeout/HZ, p)))
920 if (ntimeout > UINT_MAX/HZ)
921 sbi->exp_timeout = 0;
923 sbi->exp_timeout = ntimeout * HZ;
929 static inline int autofs4_get_set_timeout(struct autofs_sb_info *sbi,
930 unsigned long __user *p)
933 unsigned long ntimeout;
935 if ((rv = get_user(ntimeout, p)) ||
936 (rv = put_user(sbi->exp_timeout/HZ, p)))
939 if (ntimeout > ULONG_MAX/HZ)
940 sbi->exp_timeout = 0;
942 sbi->exp_timeout = ntimeout * HZ;
947 /* Return protocol version */
948 static inline int autofs4_get_protover(struct autofs_sb_info *sbi, int __user *p)
950 return put_user(sbi->version, p);
953 /* Return protocol sub version */
954 static inline int autofs4_get_protosubver(struct autofs_sb_info *sbi, int __user *p)
956 return put_user(sbi->sub_version, p);
960 * Tells the daemon whether it can umount the autofs mount.
962 static inline int autofs4_ask_umount(struct vfsmount *mnt, int __user *p)
969 DPRINTK("returning %d", status);
971 status = put_user(status, p);
976 /* Identify autofs4_dentries - this is so we can tell if there's
977 an extra dentry refcount or not. We only hold a refcount on the
978 dentry if its non-negative (ie, d_inode != NULL)
980 int is_autofs4_dentry(struct dentry *dentry)
982 return dentry && dentry->d_inode &&
983 (dentry->d_op == &autofs4_root_dentry_operations ||
984 dentry->d_op == &autofs4_dentry_operations) &&
985 dentry->d_fsdata != NULL;
989 * ioctl()'s on the root directory is the chief method for the daemon to
990 * generate kernel reactions
992 static int autofs4_root_ioctl_unlocked(struct inode *inode, struct file *filp,
993 unsigned int cmd, unsigned long arg)
995 struct autofs_sb_info *sbi = autofs4_sbi(inode->i_sb);
996 void __user *p = (void __user *)arg;
998 DPRINTK("cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u",
999 cmd,arg,sbi,task_pgrp_nr(current));
1001 if (_IOC_TYPE(cmd) != _IOC_TYPE(AUTOFS_IOC_FIRST) ||
1002 _IOC_NR(cmd) - _IOC_NR(AUTOFS_IOC_FIRST) >= AUTOFS_IOC_COUNT)
1005 if (!autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN))
1009 case AUTOFS_IOC_READY: /* Wait queue: go ahead and retry */
1010 return autofs4_wait_release(sbi,(autofs_wqt_t)arg,0);
1011 case AUTOFS_IOC_FAIL: /* Wait queue: fail with ENOENT */
1012 return autofs4_wait_release(sbi,(autofs_wqt_t)arg,-ENOENT);
1013 case AUTOFS_IOC_CATATONIC: /* Enter catatonic mode (daemon shutdown) */
1014 autofs4_catatonic_mode(sbi);
1016 case AUTOFS_IOC_PROTOVER: /* Get protocol version */
1017 return autofs4_get_protover(sbi, p);
1018 case AUTOFS_IOC_PROTOSUBVER: /* Get protocol sub version */
1019 return autofs4_get_protosubver(sbi, p);
1020 case AUTOFS_IOC_SETTIMEOUT:
1021 return autofs4_get_set_timeout(sbi, p);
1022 #ifdef CONFIG_COMPAT
1023 case AUTOFS_IOC_SETTIMEOUT32:
1024 return autofs4_compat_get_set_timeout(sbi, p);
1027 case AUTOFS_IOC_ASKUMOUNT:
1028 return autofs4_ask_umount(filp->f_path.mnt, p);
1030 /* return a single thing to expire */
1031 case AUTOFS_IOC_EXPIRE:
1032 return autofs4_expire_run(inode->i_sb,filp->f_path.mnt,sbi, p);
1033 /* same as above, but can send multiple expires through pipe */
1034 case AUTOFS_IOC_EXPIRE_MULTI:
1035 return autofs4_expire_multi(inode->i_sb,filp->f_path.mnt,sbi, p);
1042 static long autofs4_root_ioctl(struct file *filp,
1043 unsigned int cmd, unsigned long arg)
1045 struct inode *inode = filp->f_dentry->d_inode;
1046 return autofs4_root_ioctl_unlocked(inode, filp, cmd, arg);
1049 #ifdef CONFIG_COMPAT
1050 static long autofs4_root_compat_ioctl(struct file *filp,
1051 unsigned int cmd, unsigned long arg)
1053 struct inode *inode = filp->f_path.dentry->d_inode;
1056 if (cmd == AUTOFS_IOC_READY || cmd == AUTOFS_IOC_FAIL)
1057 ret = autofs4_root_ioctl_unlocked(inode, filp, cmd, arg);
1059 ret = autofs4_root_ioctl_unlocked(inode, filp, cmd,
1060 (unsigned long)compat_ptr(arg));