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);