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 if (ino && (ino->flags & AUTOFS_INF_EXPIRING)) {
137 DPRINTK("waiting for expire %p name=%.*s",
138 dentry, dentry->d_name.len, dentry->d_name.name);
140 status = autofs4_wait(sbi, dentry, NFY_NONE);
142 DPRINTK("expire done status=%d", status);
145 * If the directory still exists the mount request must
146 * continue otherwise it can't be followed at the right
147 * time during the walk.
149 status = d_invalidate(dentry);
150 if (status != -EBUSY)
154 DPRINTK("dentry=%p %.*s ino=%p",
155 dentry, dentry->d_name.len, dentry->d_name.name, dentry->d_inode);
158 * Wait for a pending mount, triggering one if there
161 if (dentry->d_inode == NULL) {
162 DPRINTK("waiting for mount name=%.*s",
163 dentry->d_name.len, dentry->d_name.name);
165 status = autofs4_wait(sbi, dentry, NFY_MOUNT);
167 DPRINTK("mount done status=%d", status);
169 /* Turn this into a real negative dentry? */
170 if (status == -ENOENT) {
171 spin_lock(&dentry->d_lock);
172 dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
173 spin_unlock(&dentry->d_lock);
176 /* Return a negative dentry, but leave it "pending" */
179 /* Trigger mount for path component or follow link */
180 } else if (flags & (TRIGGER_FLAGS | TRIGGER_INTENTS) ||
181 current->link_count) {
182 DPRINTK("waiting for mount name=%.*s",
183 dentry->d_name.len, dentry->d_name.name);
185 spin_lock(&dentry->d_lock);
186 dentry->d_flags |= DCACHE_AUTOFS_PENDING;
187 spin_unlock(&dentry->d_lock);
188 status = autofs4_wait(sbi, dentry, NFY_MOUNT);
190 DPRINTK("mount done status=%d", status);
193 spin_lock(&dentry->d_lock);
194 dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
195 spin_unlock(&dentry->d_lock);
200 /* Initialize expiry counter after successful mount */
202 ino->last_used = jiffies;
204 spin_lock(&dentry->d_lock);
205 dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
206 spin_unlock(&dentry->d_lock);
211 /* For autofs direct mounts the follow link triggers the mount */
212 static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd)
214 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
215 struct autofs_info *ino = autofs4_dentry_ino(dentry);
216 int oz_mode = autofs4_oz_mode(sbi);
217 unsigned int lookup_type;
220 DPRINTK("dentry=%p %.*s oz_mode=%d nd->flags=%d",
221 dentry, dentry->d_name.len, dentry->d_name.name, oz_mode,
224 /* If it's our master or we shouldn't trigger a mount we're done */
225 lookup_type = nd->flags & (TRIGGER_FLAGS | TRIGGER_INTENTS);
226 if (oz_mode || !lookup_type)
229 /* If an expire request is pending wait for it. */
230 if (ino && (ino->flags & AUTOFS_INF_EXPIRING)) {
231 DPRINTK("waiting for active request %p name=%.*s",
232 dentry, dentry->d_name.len, dentry->d_name.name);
234 status = autofs4_wait(sbi, dentry, NFY_NONE);
236 DPRINTK("request done status=%d", status);
240 * If the dentry contains directories then it is an
241 * autofs multi-mount with no root mount offset. So
242 * don't try to mount it again.
244 spin_lock(&dcache_lock);
245 if (!d_mountpoint(dentry) && __simple_empty(dentry)) {
246 spin_unlock(&dcache_lock);
248 status = try_to_fill_dentry(dentry, 0);
253 * The mount succeeded but if there is no root mount
254 * it must be an autofs multi-mount with no root offset
255 * so we don't need to follow the mount.
257 if (d_mountpoint(dentry)) {
258 if (!autofs4_follow_mount(&nd->path.mnt,
267 spin_unlock(&dcache_lock);
274 return ERR_PTR(status);
278 * Revalidate is called on every cache lookup. Some of those
279 * cache lookups may actually happen while the dentry is not
280 * yet completely filled in, and revalidate has to delay such
283 static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd)
285 struct inode *dir = dentry->d_parent->d_inode;
286 struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
287 int oz_mode = autofs4_oz_mode(sbi);
288 int flags = nd ? nd->flags : 0;
292 if (autofs4_ispending(dentry)) {
293 /* The daemon never causes a mount to trigger */
298 * A zero status is success otherwise we have a
299 * negative error code.
301 status = try_to_fill_dentry(dentry, flags);
306 * A status of EAGAIN here means that the dentry has gone
307 * away while waiting for an expire to complete. If we are
308 * racing with expire lookup will wait for it so this must
309 * be a revalidate and we need to send it to lookup.
311 if (status == -EAGAIN)
317 /* Negative dentry.. invalidate if "old" */
318 if (dentry->d_inode == NULL)
321 /* Check for a non-mountpoint directory with no contents */
322 spin_lock(&dcache_lock);
323 if (S_ISDIR(dentry->d_inode->i_mode) &&
324 !d_mountpoint(dentry) &&
325 __simple_empty(dentry)) {
326 DPRINTK("dentry=%p %.*s, emptydir",
327 dentry, dentry->d_name.len, dentry->d_name.name);
328 spin_unlock(&dcache_lock);
329 /* The daemon never causes a mount to trigger */
334 * A zero status is success otherwise we have a
335 * negative error code.
337 status = try_to_fill_dentry(dentry, flags);
343 spin_unlock(&dcache_lock);
348 void autofs4_dentry_release(struct dentry *de)
350 struct autofs_info *inf;
352 DPRINTK("releasing %p", de);
354 inf = autofs4_dentry_ino(de);
358 struct autofs_sb_info *sbi = autofs4_sbi(de->d_sb);
361 spin_lock(&sbi->lookup_lock);
362 if (!list_empty(&inf->active))
363 list_del(&inf->active);
364 if (!list_empty(&inf->expiring))
365 list_del(&inf->expiring);
366 spin_unlock(&sbi->lookup_lock);
372 autofs4_free_ino(inf);
376 /* For dentries of directories in the root dir */
377 static struct dentry_operations autofs4_root_dentry_operations = {
378 .d_revalidate = autofs4_revalidate,
379 .d_release = autofs4_dentry_release,
382 /* For other dentries */
383 static struct dentry_operations autofs4_dentry_operations = {
384 .d_revalidate = autofs4_revalidate,
385 .d_release = autofs4_dentry_release,
388 static struct dentry *autofs4_lookup_active(struct autofs_sb_info *sbi, struct dentry *parent, struct qstr *name)
390 unsigned int len = name->len;
391 unsigned int hash = name->hash;
392 const unsigned char *str = name->name;
393 struct list_head *p, *head;
395 spin_lock(&dcache_lock);
396 spin_lock(&sbi->lookup_lock);
397 head = &sbi->active_list;
398 list_for_each(p, head) {
399 struct autofs_info *ino;
400 struct dentry *dentry;
403 ino = list_entry(p, struct autofs_info, active);
404 dentry = ino->dentry;
406 spin_lock(&dentry->d_lock);
409 if (atomic_read(&dentry->d_count) == 0)
412 qstr = &dentry->d_name;
414 if (dentry->d_name.hash != hash)
416 if (dentry->d_parent != parent)
419 if (qstr->len != len)
421 if (memcmp(qstr->name, str, len))
424 if (d_unhashed(dentry)) {
426 spin_unlock(&dentry->d_lock);
427 spin_unlock(&sbi->lookup_lock);
428 spin_unlock(&dcache_lock);
432 spin_unlock(&dentry->d_lock);
434 spin_unlock(&sbi->lookup_lock);
435 spin_unlock(&dcache_lock);
440 static struct dentry *autofs4_lookup_expiring(struct autofs_sb_info *sbi, struct dentry *parent, struct qstr *name)
442 unsigned int len = name->len;
443 unsigned int hash = name->hash;
444 const unsigned char *str = name->name;
445 struct list_head *p, *head;
447 spin_lock(&dcache_lock);
448 spin_lock(&sbi->lookup_lock);
449 head = &sbi->expiring_list;
450 list_for_each(p, head) {
451 struct autofs_info *ino;
452 struct dentry *dentry;
455 ino = list_entry(p, struct autofs_info, expiring);
456 dentry = ino->dentry;
458 spin_lock(&dentry->d_lock);
460 /* Bad luck, we've already been dentry_iput */
461 if (!dentry->d_inode)
464 qstr = &dentry->d_name;
466 if (dentry->d_name.hash != hash)
468 if (dentry->d_parent != parent)
471 if (qstr->len != len)
473 if (memcmp(qstr->name, str, len))
476 if (d_unhashed(dentry)) {
478 spin_unlock(&dentry->d_lock);
479 spin_unlock(&sbi->lookup_lock);
480 spin_unlock(&dcache_lock);
484 spin_unlock(&dentry->d_lock);
486 spin_unlock(&sbi->lookup_lock);
487 spin_unlock(&dcache_lock);
492 /* Lookups in the root directory */
493 static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
495 struct autofs_sb_info *sbi;
496 struct autofs_info *ino;
497 struct dentry *expiring, *unhashed;
500 DPRINTK("name = %.*s",
501 dentry->d_name.len, dentry->d_name.name);
503 /* File name too long to exist */
504 if (dentry->d_name.len > NAME_MAX)
505 return ERR_PTR(-ENAMETOOLONG);
507 sbi = autofs4_sbi(dir->i_sb);
508 oz_mode = autofs4_oz_mode(sbi);
510 DPRINTK("pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d",
511 current->pid, task_pgrp_nr(current), sbi->catatonic, oz_mode);
513 expiring = autofs4_lookup_expiring(sbi, dentry->d_parent, &dentry->d_name);
516 * If we are racing with expire the request might not
517 * be quite complete but the directory has been removed
518 * so it must have been successful, so just wait for it.
520 ino = autofs4_dentry_ino(expiring);
521 while (ino && (ino->flags & AUTOFS_INF_EXPIRING)) {
522 DPRINTK("wait for incomplete expire %p name=%.*s",
523 expiring, expiring->d_name.len,
524 expiring->d_name.name);
525 autofs4_wait(sbi, expiring, NFY_NONE);
526 DPRINTK("request completed");
528 spin_lock(&sbi->lookup_lock);
529 if (!list_empty(&ino->expiring))
530 list_del_init(&ino->expiring);
531 spin_unlock(&sbi->lookup_lock);
535 unhashed = autofs4_lookup_active(sbi, dentry->d_parent, &dentry->d_name);
540 * Mark the dentry incomplete but don't hash it. We do this
541 * to serialize our inode creation operations (symlink and
542 * mkdir) which prevents deadlock during the callback to
543 * the daemon. Subsequent user space lookups for the same
544 * dentry are placed on the wait queue while the daemon
545 * itself is allowed passage unresticted so the create
546 * operation itself can then hash the dentry. Finally,
547 * we check for the hashed dentry and return the newly
550 dentry->d_op = &autofs4_root_dentry_operations;
553 * And we need to ensure that the same dentry is used for
554 * all following lookup calls until it is hashed so that
555 * the dentry flags are persistent throughout the request.
557 ino = autofs4_init_ino(NULL, sbi, 0555);
559 return ERR_PTR(-ENOMEM);
561 dentry->d_fsdata = ino;
562 ino->dentry = dentry;
564 spin_lock(&sbi->lookup_lock);
565 list_add(&ino->active, &sbi->active_list);
566 spin_unlock(&sbi->lookup_lock);
568 d_instantiate(dentry, NULL);
572 spin_lock(&dentry->d_lock);
573 dentry->d_flags |= DCACHE_AUTOFS_PENDING;
574 spin_unlock(&dentry->d_lock);
575 if (dentry->d_op && dentry->d_op->d_revalidate) {
576 mutex_unlock(&dir->i_mutex);
577 (dentry->d_op->d_revalidate)(dentry, nd);
578 mutex_lock(&dir->i_mutex);
583 * If we are still pending, check if we had to handle
584 * a signal. If so we can force a restart..
586 if (dentry->d_flags & DCACHE_AUTOFS_PENDING) {
587 /* See if we were interrupted */
588 if (signal_pending(current)) {
589 sigset_t *sigset = ¤t->pending.signal;
590 if (sigismember (sigset, SIGKILL) ||
591 sigismember (sigset, SIGQUIT) ||
592 sigismember (sigset, SIGINT)) {
595 return ERR_PTR(-ERESTARTNOINTR);
599 spin_lock(&dentry->d_lock);
600 dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
601 spin_unlock(&dentry->d_lock);
606 * If this dentry is unhashed, then we shouldn't honour this
607 * lookup. Returning ENOENT here doesn't do the right thing
608 * for all system calls, but it should be OK for the operations
609 * we permit from an autofs.
611 if (!oz_mode && d_unhashed(dentry)) {
613 * A user space application can (and has done in the past)
614 * remove and re-create this directory during the callback.
615 * This can leave us with an unhashed dentry, but a
616 * successful mount! So we need to perform another
617 * cached lookup in case the dentry now exists.
619 struct dentry *parent = dentry->d_parent;
620 struct dentry *new = d_lookup(parent, &dentry->d_name);
624 dentry = ERR_PTR(-ENOENT);
638 static int autofs4_dir_symlink(struct inode *dir,
639 struct dentry *dentry,
642 struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
643 struct autofs_info *ino = autofs4_dentry_ino(dentry);
644 struct autofs_info *p_ino;
648 DPRINTK("%s <- %.*s", symname,
649 dentry->d_name.len, dentry->d_name.name);
651 if (!autofs4_oz_mode(sbi))
654 ino = autofs4_init_ino(ino, sbi, S_IFLNK | 0555);
658 spin_lock(&sbi->lookup_lock);
659 if (!list_empty(&ino->active))
660 list_del_init(&ino->active);
661 spin_unlock(&sbi->lookup_lock);
663 ino->size = strlen(symname);
664 cp = kmalloc(ino->size + 1, GFP_KERNEL);
666 if (!dentry->d_fsdata)
673 inode = autofs4_get_inode(dir->i_sb, ino);
676 if (!dentry->d_fsdata)
680 d_add(dentry, inode);
682 if (dir == dir->i_sb->s_root->d_inode)
683 dentry->d_op = &autofs4_root_dentry_operations;
685 dentry->d_op = &autofs4_dentry_operations;
687 dentry->d_fsdata = ino;
688 ino->dentry = dget(dentry);
689 atomic_inc(&ino->count);
690 p_ino = autofs4_dentry_ino(dentry->d_parent);
691 if (p_ino && dentry->d_parent != dentry)
692 atomic_inc(&p_ino->count);
696 dir->i_mtime = CURRENT_TIME;
704 * Normal filesystems would do a "d_delete()" to tell the VFS dcache
705 * that the file no longer exists. However, doing that means that the
706 * VFS layer can turn the dentry into a negative dentry. We don't want
707 * this, because the unlink is probably the result of an expire.
708 * We simply d_drop it and add it to a expiring list in the super block,
709 * which allows the dentry lookup to check for an incomplete expire.
711 * If a process is blocked on the dentry waiting for the expire to finish,
712 * it will invalidate the dentry and try to mount with a new one.
714 * Also see autofs4_dir_rmdir()..
716 static int autofs4_dir_unlink(struct inode *dir, struct dentry *dentry)
718 struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
719 struct autofs_info *ino = autofs4_dentry_ino(dentry);
720 struct autofs_info *p_ino;
722 /* This allows root to remove symlinks */
723 if (!autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN))
726 if (atomic_dec_and_test(&ino->count)) {
727 p_ino = autofs4_dentry_ino(dentry->d_parent);
728 if (p_ino && dentry->d_parent != dentry)
729 atomic_dec(&p_ino->count);
733 dentry->d_inode->i_size = 0;
734 clear_nlink(dentry->d_inode);
736 dir->i_mtime = CURRENT_TIME;
738 spin_lock(&dcache_lock);
739 spin_lock(&sbi->lookup_lock);
740 if (list_empty(&ino->expiring))
741 list_add(&ino->expiring, &sbi->expiring_list);
742 spin_unlock(&sbi->lookup_lock);
743 spin_lock(&dentry->d_lock);
745 spin_unlock(&dentry->d_lock);
746 spin_unlock(&dcache_lock);
751 static int autofs4_dir_rmdir(struct inode *dir, struct dentry *dentry)
753 struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
754 struct autofs_info *ino = autofs4_dentry_ino(dentry);
755 struct autofs_info *p_ino;
757 DPRINTK("dentry %p, removing %.*s",
758 dentry, dentry->d_name.len, dentry->d_name.name);
760 if (!autofs4_oz_mode(sbi))
763 spin_lock(&dcache_lock);
764 if (!list_empty(&dentry->d_subdirs)) {
765 spin_unlock(&dcache_lock);
768 spin_lock(&sbi->lookup_lock);
769 if (list_empty(&ino->expiring))
770 list_add(&ino->expiring, &sbi->expiring_list);
771 spin_unlock(&sbi->lookup_lock);
772 spin_lock(&dentry->d_lock);
774 spin_unlock(&dentry->d_lock);
775 spin_unlock(&dcache_lock);
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);
783 dentry->d_inode->i_size = 0;
784 clear_nlink(dentry->d_inode);
792 static int autofs4_dir_mkdir(struct inode *dir, struct dentry *dentry, int mode)
794 struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
795 struct autofs_info *ino = autofs4_dentry_ino(dentry);
796 struct autofs_info *p_ino;
799 if (!autofs4_oz_mode(sbi))
802 DPRINTK("dentry %p, creating %.*s",
803 dentry, dentry->d_name.len, dentry->d_name.name);
805 ino = autofs4_init_ino(ino, sbi, S_IFDIR | 0555);
809 spin_lock(&sbi->lookup_lock);
810 if (!list_empty(&ino->active))
811 list_del_init(&ino->active);
812 spin_unlock(&sbi->lookup_lock);
814 inode = autofs4_get_inode(dir->i_sb, ino);
816 if (!dentry->d_fsdata)
820 d_add(dentry, inode);
822 if (dir == dir->i_sb->s_root->d_inode)
823 dentry->d_op = &autofs4_root_dentry_operations;
825 dentry->d_op = &autofs4_dentry_operations;
827 dentry->d_fsdata = ino;
828 ino->dentry = dget(dentry);
829 atomic_inc(&ino->count);
830 p_ino = autofs4_dentry_ino(dentry->d_parent);
831 if (p_ino && dentry->d_parent != dentry)
832 atomic_inc(&p_ino->count);
835 dir->i_mtime = CURRENT_TIME;
840 /* Get/set timeout ioctl() operation */
841 static inline int autofs4_get_set_timeout(struct autofs_sb_info *sbi,
842 unsigned long __user *p)
845 unsigned long ntimeout;
847 if ((rv = get_user(ntimeout, p)) ||
848 (rv = put_user(sbi->exp_timeout/HZ, p)))
851 if (ntimeout > ULONG_MAX/HZ)
852 sbi->exp_timeout = 0;
854 sbi->exp_timeout = ntimeout * HZ;
859 /* Return protocol version */
860 static inline int autofs4_get_protover(struct autofs_sb_info *sbi, int __user *p)
862 return put_user(sbi->version, p);
865 /* Return protocol sub version */
866 static inline int autofs4_get_protosubver(struct autofs_sb_info *sbi, int __user *p)
868 return put_user(sbi->sub_version, p);
872 * Tells the daemon whether we need to reghost or not. Also, clears
873 * the reghost_needed flag.
875 static inline int autofs4_ask_reghost(struct autofs_sb_info *sbi, int __user *p)
879 DPRINTK("returning %d", sbi->needs_reghost);
881 status = put_user(sbi->needs_reghost, p);
885 sbi->needs_reghost = 0;
890 * Enable / Disable reghosting ioctl() operation
892 static inline int autofs4_toggle_reghost(struct autofs_sb_info *sbi, int __user *p)
897 status = get_user(val, p);
899 DPRINTK("reghost = %d", val);
904 /* turn on/off reghosting, with the val */
905 sbi->reghost_enabled = val;
910 * Tells the daemon whether it can umount the autofs mount.
912 static inline int autofs4_ask_umount(struct vfsmount *mnt, int __user *p)
919 DPRINTK("returning %d", status);
921 status = put_user(status, p);
926 /* Identify autofs4_dentries - this is so we can tell if there's
927 an extra dentry refcount or not. We only hold a refcount on the
928 dentry if its non-negative (ie, d_inode != NULL)
930 int is_autofs4_dentry(struct dentry *dentry)
932 return dentry && dentry->d_inode &&
933 (dentry->d_op == &autofs4_root_dentry_operations ||
934 dentry->d_op == &autofs4_dentry_operations) &&
935 dentry->d_fsdata != NULL;
939 * ioctl()'s on the root directory is the chief method for the daemon to
940 * generate kernel reactions
942 static int autofs4_root_ioctl(struct inode *inode, struct file *filp,
943 unsigned int cmd, unsigned long arg)
945 struct autofs_sb_info *sbi = autofs4_sbi(inode->i_sb);
946 void __user *p = (void __user *)arg;
948 DPRINTK("cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u",
949 cmd,arg,sbi,task_pgrp_nr(current));
951 if (_IOC_TYPE(cmd) != _IOC_TYPE(AUTOFS_IOC_FIRST) ||
952 _IOC_NR(cmd) - _IOC_NR(AUTOFS_IOC_FIRST) >= AUTOFS_IOC_COUNT)
955 if (!autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN))
959 case AUTOFS_IOC_READY: /* Wait queue: go ahead and retry */
960 return autofs4_wait_release(sbi,(autofs_wqt_t)arg,0);
961 case AUTOFS_IOC_FAIL: /* Wait queue: fail with ENOENT */
962 return autofs4_wait_release(sbi,(autofs_wqt_t)arg,-ENOENT);
963 case AUTOFS_IOC_CATATONIC: /* Enter catatonic mode (daemon shutdown) */
964 autofs4_catatonic_mode(sbi);
966 case AUTOFS_IOC_PROTOVER: /* Get protocol version */
967 return autofs4_get_protover(sbi, p);
968 case AUTOFS_IOC_PROTOSUBVER: /* Get protocol sub version */
969 return autofs4_get_protosubver(sbi, p);
970 case AUTOFS_IOC_SETTIMEOUT:
971 return autofs4_get_set_timeout(sbi, p);
973 case AUTOFS_IOC_TOGGLEREGHOST:
974 return autofs4_toggle_reghost(sbi, p);
975 case AUTOFS_IOC_ASKREGHOST:
976 return autofs4_ask_reghost(sbi, p);
978 case AUTOFS_IOC_ASKUMOUNT:
979 return autofs4_ask_umount(filp->f_path.mnt, p);
981 /* return a single thing to expire */
982 case AUTOFS_IOC_EXPIRE:
983 return autofs4_expire_run(inode->i_sb,filp->f_path.mnt,sbi, p);
984 /* same as above, but can send multiple expires through pipe */
985 case AUTOFS_IOC_EXPIRE_MULTI:
986 return autofs4_expire_multi(inode->i_sb,filp->f_path.mnt,sbi, p);