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))
245 * We shouldn't need to do this but we have no way
246 * of knowing what may have been done so try a follow
249 autofs4_follow_mount(&nd->path.mnt, &nd->path.dentry);
252 spin_unlock(&sbi->fs_lock);
256 /* If an expire request is pending everyone must wait. */
257 spin_lock(&sbi->fs_lock);
258 if (ino->flags & AUTOFS_INF_EXPIRING) {
259 spin_unlock(&sbi->fs_lock);
261 DPRINTK("waiting for active request %p name=%.*s",
262 dentry, dentry->d_name.len, dentry->d_name.name);
264 status = autofs4_wait(sbi, dentry, NFY_NONE);
265 wait_for_completion(&ino->expire_complete);
267 DPRINTK("request done status=%d", status);
271 spin_unlock(&sbi->fs_lock);
273 /* We trigger a mount for almost all flags */
274 lookup_type = nd->flags & (TRIGGER_FLAGS | TRIGGER_INTENTS);
275 if (!(lookup_type || dentry->d_flags & DCACHE_AUTOFS_PENDING))
279 * If the dentry contains directories then it is an autofs
280 * multi-mount with no root mount offset. So don't try to
283 spin_lock(&dcache_lock);
284 if (dentry->d_flags & DCACHE_AUTOFS_PENDING ||
285 (!d_mountpoint(dentry) && __simple_empty(dentry))) {
286 spin_unlock(&dcache_lock);
288 status = try_to_fill_dentry(dentry, 0);
294 spin_unlock(&dcache_lock);
297 * If there is no root mount it must be an autofs
298 * multi-mount with no root offset so we don't need
301 if (d_mountpoint(dentry)) {
302 if (!autofs4_follow_mount(&nd->path.mnt,
314 return ERR_PTR(status);
318 * Revalidate is called on every cache lookup. Some of those
319 * cache lookups may actually happen while the dentry is not
320 * yet completely filled in, and revalidate has to delay such
323 static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd)
325 struct inode *dir = dentry->d_parent->d_inode;
326 struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
327 int oz_mode = autofs4_oz_mode(sbi);
328 int flags = nd ? nd->flags : 0;
332 spin_lock(&sbi->fs_lock);
333 if (autofs4_ispending(dentry)) {
334 /* The daemon never causes a mount to trigger */
335 spin_unlock(&sbi->fs_lock);
341 * A zero status is success otherwise we have a
342 * negative error code.
344 status = try_to_fill_dentry(dentry, flags);
349 * A status of EAGAIN here means that the dentry has gone
350 * away while waiting for an expire to complete. If we are
351 * racing with expire lookup will wait for it so this must
352 * be a revalidate and we need to send it to lookup.
354 if (status == -EAGAIN)
359 spin_unlock(&sbi->fs_lock);
361 /* Negative dentry.. invalidate if "old" */
362 if (dentry->d_inode == NULL)
365 /* Check for a non-mountpoint directory with no contents */
366 spin_lock(&dcache_lock);
367 if (S_ISDIR(dentry->d_inode->i_mode) &&
368 !d_mountpoint(dentry) &&
369 __simple_empty(dentry)) {
370 DPRINTK("dentry=%p %.*s, emptydir",
371 dentry, dentry->d_name.len, dentry->d_name.name);
372 spin_unlock(&dcache_lock);
374 /* The daemon never causes a mount to trigger */
379 * A zero status is success otherwise we have a
380 * negative error code.
382 status = try_to_fill_dentry(dentry, flags);
388 spin_unlock(&dcache_lock);
393 void autofs4_dentry_release(struct dentry *de)
395 struct autofs_info *inf;
397 DPRINTK("releasing %p", de);
399 inf = autofs4_dentry_ino(de);
403 struct autofs_sb_info *sbi = autofs4_sbi(de->d_sb);
406 spin_lock(&sbi->lookup_lock);
407 if (!list_empty(&inf->active))
408 list_del(&inf->active);
409 if (!list_empty(&inf->expiring))
410 list_del(&inf->expiring);
411 spin_unlock(&sbi->lookup_lock);
417 autofs4_free_ino(inf);
421 /* For dentries of directories in the root dir */
422 static struct dentry_operations autofs4_root_dentry_operations = {
423 .d_revalidate = autofs4_revalidate,
424 .d_release = autofs4_dentry_release,
427 /* For other dentries */
428 static struct dentry_operations autofs4_dentry_operations = {
429 .d_revalidate = autofs4_revalidate,
430 .d_release = autofs4_dentry_release,
433 static struct dentry *autofs4_lookup_active(struct autofs_sb_info *sbi, struct dentry *parent, struct qstr *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(&dcache_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 *dentry;
448 ino = list_entry(p, struct autofs_info, active);
449 dentry = ino->dentry;
451 spin_lock(&dentry->d_lock);
454 if (atomic_read(&dentry->d_count) == 0)
457 qstr = &dentry->d_name;
459 if (dentry->d_name.hash != hash)
461 if (dentry->d_parent != parent)
464 if (qstr->len != len)
466 if (memcmp(qstr->name, str, len))
469 if (d_unhashed(dentry)) {
471 spin_unlock(&dentry->d_lock);
472 spin_unlock(&sbi->lookup_lock);
473 spin_unlock(&dcache_lock);
477 spin_unlock(&dentry->d_lock);
479 spin_unlock(&sbi->lookup_lock);
480 spin_unlock(&dcache_lock);
485 static struct dentry *autofs4_lookup_expiring(struct autofs_sb_info *sbi, struct dentry *parent, struct qstr *name)
487 unsigned int len = name->len;
488 unsigned int hash = name->hash;
489 const unsigned char *str = name->name;
490 struct list_head *p, *head;
492 spin_lock(&dcache_lock);
493 spin_lock(&sbi->lookup_lock);
494 head = &sbi->expiring_list;
495 list_for_each(p, head) {
496 struct autofs_info *ino;
497 struct dentry *dentry;
500 ino = list_entry(p, struct autofs_info, expiring);
501 dentry = ino->dentry;
503 spin_lock(&dentry->d_lock);
505 /* Bad luck, we've already been dentry_iput */
506 if (!dentry->d_inode)
509 qstr = &dentry->d_name;
511 if (dentry->d_name.hash != hash)
513 if (dentry->d_parent != parent)
516 if (qstr->len != len)
518 if (memcmp(qstr->name, str, len))
521 if (d_unhashed(dentry)) {
523 spin_unlock(&dentry->d_lock);
524 spin_unlock(&sbi->lookup_lock);
525 spin_unlock(&dcache_lock);
529 spin_unlock(&dentry->d_lock);
531 spin_unlock(&sbi->lookup_lock);
532 spin_unlock(&dcache_lock);
537 /* Lookups in the root directory */
538 static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
540 struct autofs_sb_info *sbi;
541 struct autofs_info *ino;
542 struct dentry *expiring, *unhashed;
545 DPRINTK("name = %.*s",
546 dentry->d_name.len, dentry->d_name.name);
548 /* File name too long to exist */
549 if (dentry->d_name.len > NAME_MAX)
550 return ERR_PTR(-ENAMETOOLONG);
552 sbi = autofs4_sbi(dir->i_sb);
553 oz_mode = autofs4_oz_mode(sbi);
555 DPRINTK("pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d",
556 current->pid, task_pgrp_nr(current), sbi->catatonic, oz_mode);
558 expiring = autofs4_lookup_expiring(sbi, dentry->d_parent, &dentry->d_name);
561 * If we are racing with expire the request might not
562 * be quite complete but the directory has been removed
563 * so it must have been successful, so just wait for it.
565 ino = autofs4_dentry_ino(expiring);
566 spin_lock(&sbi->fs_lock);
567 if (ino->flags & AUTOFS_INF_EXPIRING) {
568 spin_unlock(&sbi->fs_lock);
569 DPRINTK("wait for incomplete expire %p name=%.*s",
570 expiring, expiring->d_name.len,
571 expiring->d_name.name);
572 autofs4_wait(sbi, expiring, NFY_NONE);
573 wait_for_completion(&ino->expire_complete);
574 DPRINTK("request completed");
577 spin_unlock(&sbi->fs_lock);
579 spin_lock(&sbi->lookup_lock);
580 if (!list_empty(&ino->expiring))
581 list_del_init(&ino->expiring);
582 spin_unlock(&sbi->lookup_lock);
586 unhashed = autofs4_lookup_active(sbi, dentry->d_parent, &dentry->d_name);
591 * Mark the dentry incomplete but don't hash it. We do this
592 * to serialize our inode creation operations (symlink and
593 * mkdir) which prevents deadlock during the callback to
594 * the daemon. Subsequent user space lookups for the same
595 * dentry are placed on the wait queue while the daemon
596 * itself is allowed passage unresticted so the create
597 * operation itself can then hash the dentry. Finally,
598 * we check for the hashed dentry and return the newly
601 dentry->d_op = &autofs4_root_dentry_operations;
604 * And we need to ensure that the same dentry is used for
605 * all following lookup calls until it is hashed so that
606 * the dentry flags are persistent throughout the request.
608 ino = autofs4_init_ino(NULL, sbi, 0555);
610 return ERR_PTR(-ENOMEM);
612 dentry->d_fsdata = ino;
613 ino->dentry = dentry;
615 spin_lock(&sbi->lookup_lock);
616 list_add(&ino->active, &sbi->active_list);
617 spin_unlock(&sbi->lookup_lock);
619 d_instantiate(dentry, NULL);
623 spin_lock(&dentry->d_lock);
624 dentry->d_flags |= DCACHE_AUTOFS_PENDING;
625 spin_unlock(&dentry->d_lock);
626 if (dentry->d_op && dentry->d_op->d_revalidate) {
627 mutex_unlock(&dir->i_mutex);
628 (dentry->d_op->d_revalidate)(dentry, nd);
629 mutex_lock(&dir->i_mutex);
634 * If we are still pending, check if we had to handle
635 * a signal. If so we can force a restart..
637 if (dentry->d_flags & DCACHE_AUTOFS_PENDING) {
638 /* See if we were interrupted */
639 if (signal_pending(current)) {
640 sigset_t *sigset = ¤t->pending.signal;
641 if (sigismember (sigset, SIGKILL) ||
642 sigismember (sigset, SIGQUIT) ||
643 sigismember (sigset, SIGINT)) {
646 return ERR_PTR(-ERESTARTNOINTR);
650 spin_lock(&dentry->d_lock);
651 dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
652 spin_unlock(&dentry->d_lock);
657 * If this dentry is unhashed, then we shouldn't honour this
658 * lookup. Returning ENOENT here doesn't do the right thing
659 * for all system calls, but it should be OK for the operations
660 * we permit from an autofs.
662 if (!oz_mode && d_unhashed(dentry)) {
664 * A user space application can (and has done in the past)
665 * remove and re-create this directory during the callback.
666 * This can leave us with an unhashed dentry, but a
667 * successful mount! So we need to perform another
668 * cached lookup in case the dentry now exists.
670 struct dentry *parent = dentry->d_parent;
671 struct dentry *new = d_lookup(parent, &dentry->d_name);
675 dentry = ERR_PTR(-ENOENT);
689 static int autofs4_dir_symlink(struct inode *dir,
690 struct dentry *dentry,
693 struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
694 struct autofs_info *ino = autofs4_dentry_ino(dentry);
695 struct autofs_info *p_ino;
699 DPRINTK("%s <- %.*s", symname,
700 dentry->d_name.len, dentry->d_name.name);
702 if (!autofs4_oz_mode(sbi))
705 ino = autofs4_init_ino(ino, sbi, S_IFLNK | 0555);
709 spin_lock(&sbi->lookup_lock);
710 if (!list_empty(&ino->active))
711 list_del_init(&ino->active);
712 spin_unlock(&sbi->lookup_lock);
714 ino->size = strlen(symname);
715 cp = kmalloc(ino->size + 1, GFP_KERNEL);
717 if (!dentry->d_fsdata)
724 inode = autofs4_get_inode(dir->i_sb, ino);
727 if (!dentry->d_fsdata)
731 d_add(dentry, inode);
733 if (dir == dir->i_sb->s_root->d_inode)
734 dentry->d_op = &autofs4_root_dentry_operations;
736 dentry->d_op = &autofs4_dentry_operations;
738 dentry->d_fsdata = ino;
739 ino->dentry = dget(dentry);
740 atomic_inc(&ino->count);
741 p_ino = autofs4_dentry_ino(dentry->d_parent);
742 if (p_ino && dentry->d_parent != dentry)
743 atomic_inc(&p_ino->count);
747 dir->i_mtime = CURRENT_TIME;
755 * Normal filesystems would do a "d_delete()" to tell the VFS dcache
756 * that the file no longer exists. However, doing that means that the
757 * VFS layer can turn the dentry into a negative dentry. We don't want
758 * this, because the unlink is probably the result of an expire.
759 * We simply d_drop it and add it to a expiring list in the super block,
760 * which allows the dentry lookup to check for an incomplete expire.
762 * If a process is blocked on the dentry waiting for the expire to finish,
763 * it will invalidate the dentry and try to mount with a new one.
765 * Also see autofs4_dir_rmdir()..
767 static int autofs4_dir_unlink(struct inode *dir, struct dentry *dentry)
769 struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
770 struct autofs_info *ino = autofs4_dentry_ino(dentry);
771 struct autofs_info *p_ino;
773 /* This allows root to remove symlinks */
774 if (!autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN))
777 if (atomic_dec_and_test(&ino->count)) {
778 p_ino = autofs4_dentry_ino(dentry->d_parent);
779 if (p_ino && dentry->d_parent != dentry)
780 atomic_dec(&p_ino->count);
784 dentry->d_inode->i_size = 0;
785 clear_nlink(dentry->d_inode);
787 dir->i_mtime = CURRENT_TIME;
789 spin_lock(&dcache_lock);
790 spin_lock(&sbi->lookup_lock);
791 if (list_empty(&ino->expiring))
792 list_add(&ino->expiring, &sbi->expiring_list);
793 spin_unlock(&sbi->lookup_lock);
794 spin_lock(&dentry->d_lock);
796 spin_unlock(&dentry->d_lock);
797 spin_unlock(&dcache_lock);
802 static int autofs4_dir_rmdir(struct inode *dir, struct dentry *dentry)
804 struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
805 struct autofs_info *ino = autofs4_dentry_ino(dentry);
806 struct autofs_info *p_ino;
808 DPRINTK("dentry %p, removing %.*s",
809 dentry, dentry->d_name.len, dentry->d_name.name);
811 if (!autofs4_oz_mode(sbi))
814 spin_lock(&dcache_lock);
815 if (!list_empty(&dentry->d_subdirs)) {
816 spin_unlock(&dcache_lock);
819 spin_lock(&sbi->lookup_lock);
820 if (list_empty(&ino->expiring))
821 list_add(&ino->expiring, &sbi->expiring_list);
822 spin_unlock(&sbi->lookup_lock);
823 spin_lock(&dentry->d_lock);
825 spin_unlock(&dentry->d_lock);
826 spin_unlock(&dcache_lock);
828 if (atomic_dec_and_test(&ino->count)) {
829 p_ino = autofs4_dentry_ino(dentry->d_parent);
830 if (p_ino && dentry->d_parent != dentry)
831 atomic_dec(&p_ino->count);
834 dentry->d_inode->i_size = 0;
835 clear_nlink(dentry->d_inode);
843 static int autofs4_dir_mkdir(struct inode *dir, struct dentry *dentry, int mode)
845 struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
846 struct autofs_info *ino = autofs4_dentry_ino(dentry);
847 struct autofs_info *p_ino;
850 if (!autofs4_oz_mode(sbi))
853 DPRINTK("dentry %p, creating %.*s",
854 dentry, dentry->d_name.len, dentry->d_name.name);
856 ino = autofs4_init_ino(ino, sbi, S_IFDIR | 0555);
860 spin_lock(&sbi->lookup_lock);
861 if (!list_empty(&ino->active))
862 list_del_init(&ino->active);
863 spin_unlock(&sbi->lookup_lock);
865 inode = autofs4_get_inode(dir->i_sb, ino);
867 if (!dentry->d_fsdata)
871 d_add(dentry, inode);
873 if (dir == dir->i_sb->s_root->d_inode)
874 dentry->d_op = &autofs4_root_dentry_operations;
876 dentry->d_op = &autofs4_dentry_operations;
878 dentry->d_fsdata = ino;
879 ino->dentry = dget(dentry);
880 atomic_inc(&ino->count);
881 p_ino = autofs4_dentry_ino(dentry->d_parent);
882 if (p_ino && dentry->d_parent != dentry)
883 atomic_inc(&p_ino->count);
886 dir->i_mtime = CURRENT_TIME;
891 /* Get/set timeout ioctl() operation */
892 static inline int autofs4_get_set_timeout(struct autofs_sb_info *sbi,
893 unsigned long __user *p)
896 unsigned long ntimeout;
898 if ((rv = get_user(ntimeout, p)) ||
899 (rv = put_user(sbi->exp_timeout/HZ, p)))
902 if (ntimeout > ULONG_MAX/HZ)
903 sbi->exp_timeout = 0;
905 sbi->exp_timeout = ntimeout * HZ;
910 /* Return protocol version */
911 static inline int autofs4_get_protover(struct autofs_sb_info *sbi, int __user *p)
913 return put_user(sbi->version, p);
916 /* Return protocol sub version */
917 static inline int autofs4_get_protosubver(struct autofs_sb_info *sbi, int __user *p)
919 return put_user(sbi->sub_version, p);
923 * Tells the daemon whether we need to reghost or not. Also, clears
924 * the reghost_needed flag.
926 static inline int autofs4_ask_reghost(struct autofs_sb_info *sbi, int __user *p)
930 DPRINTK("returning %d", sbi->needs_reghost);
932 status = put_user(sbi->needs_reghost, p);
936 sbi->needs_reghost = 0;
941 * Enable / Disable reghosting ioctl() operation
943 static inline int autofs4_toggle_reghost(struct autofs_sb_info *sbi, int __user *p)
948 status = get_user(val, p);
950 DPRINTK("reghost = %d", val);
955 /* turn on/off reghosting, with the val */
956 sbi->reghost_enabled = val;
961 * Tells the daemon whether it can umount the autofs mount.
963 static inline int autofs4_ask_umount(struct vfsmount *mnt, int __user *p)
970 DPRINTK("returning %d", status);
972 status = put_user(status, p);
977 /* Identify autofs4_dentries - this is so we can tell if there's
978 an extra dentry refcount or not. We only hold a refcount on the
979 dentry if its non-negative (ie, d_inode != NULL)
981 int is_autofs4_dentry(struct dentry *dentry)
983 return dentry && dentry->d_inode &&
984 (dentry->d_op == &autofs4_root_dentry_operations ||
985 dentry->d_op == &autofs4_dentry_operations) &&
986 dentry->d_fsdata != NULL;
990 * ioctl()'s on the root directory is the chief method for the daemon to
991 * generate kernel reactions
993 static int autofs4_root_ioctl(struct inode *inode, struct file *filp,
994 unsigned int cmd, unsigned long arg)
996 struct autofs_sb_info *sbi = autofs4_sbi(inode->i_sb);
997 void __user *p = (void __user *)arg;
999 DPRINTK("cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u",
1000 cmd,arg,sbi,task_pgrp_nr(current));
1002 if (_IOC_TYPE(cmd) != _IOC_TYPE(AUTOFS_IOC_FIRST) ||
1003 _IOC_NR(cmd) - _IOC_NR(AUTOFS_IOC_FIRST) >= AUTOFS_IOC_COUNT)
1006 if (!autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN))
1010 case AUTOFS_IOC_READY: /* Wait queue: go ahead and retry */
1011 return autofs4_wait_release(sbi,(autofs_wqt_t)arg,0);
1012 case AUTOFS_IOC_FAIL: /* Wait queue: fail with ENOENT */
1013 return autofs4_wait_release(sbi,(autofs_wqt_t)arg,-ENOENT);
1014 case AUTOFS_IOC_CATATONIC: /* Enter catatonic mode (daemon shutdown) */
1015 autofs4_catatonic_mode(sbi);
1017 case AUTOFS_IOC_PROTOVER: /* Get protocol version */
1018 return autofs4_get_protover(sbi, p);
1019 case AUTOFS_IOC_PROTOSUBVER: /* Get protocol sub version */
1020 return autofs4_get_protosubver(sbi, p);
1021 case AUTOFS_IOC_SETTIMEOUT:
1022 return autofs4_get_set_timeout(sbi, p);
1024 case AUTOFS_IOC_TOGGLEREGHOST:
1025 return autofs4_toggle_reghost(sbi, p);
1026 case AUTOFS_IOC_ASKREGHOST:
1027 return autofs4_ask_reghost(sbi, p);
1029 case AUTOFS_IOC_ASKUMOUNT:
1030 return autofs4_ask_umount(filp->f_path.mnt, p);
1032 /* return a single thing to expire */
1033 case AUTOFS_IOC_EXPIRE:
1034 return autofs4_expire_run(inode->i_sb,filp->f_path.mnt,sbi, p);
1035 /* same as above, but can send multiple expires through pipe */
1036 case AUTOFS_IOC_EXPIRE_MULTI:
1037 return autofs4_expire_multi(inode->i_sb,filp->f_path.mnt,sbi, p);