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>
20 #include <linux/smp_lock.h>
23 static int autofs4_dir_symlink(struct inode *,struct dentry *,const char *);
24 static int autofs4_dir_unlink(struct inode *,struct dentry *);
25 static int autofs4_dir_rmdir(struct inode *,struct dentry *);
26 static int autofs4_dir_mkdir(struct inode *,struct dentry *,int);
27 static int autofs4_root_ioctl(struct inode *, struct file *,unsigned int,unsigned long);
28 static int autofs4_dir_open(struct inode *inode, struct file *file);
29 static int autofs4_dir_close(struct inode *inode, struct file *file);
30 static int autofs4_dir_readdir(struct file * filp, void * dirent, filldir_t filldir);
31 static int autofs4_root_readdir(struct file * filp, void * dirent, filldir_t filldir);
32 static struct dentry *autofs4_lookup(struct inode *,struct dentry *, struct nameidata *);
33 static void *autofs4_follow_link(struct dentry *, struct nameidata *);
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 = autofs4_dir_close,
46 .read = generic_read_dir,
47 .readdir = autofs4_dir_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 vfsmount *mnt = file->f_path.mnt;
100 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
101 struct dentry *cursor;
104 status = dcache_dir_open(inode, file);
108 cursor = file->private_data;
109 cursor->d_fsdata = NULL;
111 DPRINTK("file=%p dentry=%p %.*s",
112 file, dentry, dentry->d_name.len, dentry->d_name.name);
114 if (autofs4_oz_mode(sbi))
117 if (autofs4_ispending(dentry)) {
118 DPRINTK("dentry busy");
119 dcache_dir_close(inode, file);
125 if (!d_mountpoint(dentry) && dentry->d_op && dentry->d_op->d_revalidate) {
129 /* In case there are stale directory dentrys from a failed mount */
130 spin_lock(&dcache_lock);
131 empty = list_empty(&dentry->d_subdirs);
132 spin_unlock(&dcache_lock);
135 d_invalidate(dentry);
137 nd.flags = LOOKUP_DIRECTORY;
138 ret = (dentry->d_op->d_revalidate)(dentry, &nd);
143 dcache_dir_close(inode, file);
148 if (d_mountpoint(dentry)) {
149 struct file *fp = NULL;
150 struct vfsmount *fp_mnt = mntget(mnt);
151 struct dentry *fp_dentry = dget(dentry);
153 if (!autofs4_follow_mount(&fp_mnt, &fp_dentry)) {
156 dcache_dir_close(inode, file);
160 fp = dentry_open(fp_dentry, fp_mnt, file->f_flags);
161 status = PTR_ERR(fp);
163 dcache_dir_close(inode, file);
166 cursor->d_fsdata = fp;
173 static int autofs4_dir_close(struct inode *inode, struct file *file)
175 struct dentry *dentry = file->f_path.dentry;
176 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
177 struct dentry *cursor = file->private_data;
180 DPRINTK("file=%p dentry=%p %.*s",
181 file, dentry, dentry->d_name.len, dentry->d_name.name);
183 if (autofs4_oz_mode(sbi))
186 if (autofs4_ispending(dentry)) {
187 DPRINTK("dentry busy");
192 if (d_mountpoint(dentry)) {
193 struct file *fp = cursor->d_fsdata;
198 filp_close(fp, current->files);
201 dcache_dir_close(inode, file);
205 static int autofs4_dir_readdir(struct file *file, void *dirent, filldir_t filldir)
207 struct dentry *dentry = file->f_path.dentry;
208 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
209 struct dentry *cursor = file->private_data;
212 DPRINTK("file=%p dentry=%p %.*s",
213 file, dentry, dentry->d_name.len, dentry->d_name.name);
215 if (autofs4_oz_mode(sbi))
218 if (autofs4_ispending(dentry)) {
219 DPRINTK("dentry busy");
223 if (d_mountpoint(dentry)) {
224 struct file *fp = cursor->d_fsdata;
229 if (!fp->f_op || !fp->f_op->readdir)
232 status = vfs_readdir(fp, filldir, dirent);
233 file->f_pos = fp->f_pos;
235 autofs4_copy_atime(file, fp);
239 return dcache_readdir(file, dirent, filldir);
242 static int try_to_fill_dentry(struct dentry *dentry, int flags)
244 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
245 struct autofs_info *ino = autofs4_dentry_ino(dentry);
248 /* Block on any pending expiry here; invalidate the dentry
249 when expiration is done to trigger mount request with a new
251 if (ino && (ino->flags & AUTOFS_INF_EXPIRING)) {
252 DPRINTK("waiting for expire %p name=%.*s",
253 dentry, dentry->d_name.len, dentry->d_name.name);
255 status = autofs4_wait(sbi, dentry, NFY_NONE);
257 DPRINTK("expire done status=%d", status);
260 * If the directory still exists the mount request must
261 * continue otherwise it can't be followed at the right
262 * time during the walk.
264 status = d_invalidate(dentry);
265 if (status != -EBUSY)
269 DPRINTK("dentry=%p %.*s ino=%p",
270 dentry, dentry->d_name.len, dentry->d_name.name, dentry->d_inode);
273 * Wait for a pending mount, triggering one if there
276 if (dentry->d_inode == NULL) {
277 DPRINTK("waiting for mount name=%.*s",
278 dentry->d_name.len, dentry->d_name.name);
280 status = autofs4_wait(sbi, dentry, NFY_MOUNT);
282 DPRINTK("mount done status=%d", status);
284 /* Turn this into a real negative dentry? */
285 if (status == -ENOENT) {
286 spin_lock(&dentry->d_lock);
287 dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
288 spin_unlock(&dentry->d_lock);
291 /* Return a negative dentry, but leave it "pending" */
294 /* Trigger mount for path component or follow link */
295 } else if (flags & (LOOKUP_CONTINUE | LOOKUP_DIRECTORY) ||
296 current->link_count) {
297 DPRINTK("waiting for mount name=%.*s",
298 dentry->d_name.len, dentry->d_name.name);
300 spin_lock(&dentry->d_lock);
301 dentry->d_flags |= DCACHE_AUTOFS_PENDING;
302 spin_unlock(&dentry->d_lock);
303 status = autofs4_wait(sbi, dentry, NFY_MOUNT);
305 DPRINTK("mount done status=%d", status);
308 spin_lock(&dentry->d_lock);
309 dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
310 spin_unlock(&dentry->d_lock);
315 /* Initialize expiry counter after successful mount */
317 ino->last_used = jiffies;
319 spin_lock(&dentry->d_lock);
320 dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
321 spin_unlock(&dentry->d_lock);
325 /* For autofs direct mounts the follow link triggers the mount */
326 static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd)
328 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
329 struct autofs_info *ino = autofs4_dentry_ino(dentry);
330 int oz_mode = autofs4_oz_mode(sbi);
331 unsigned int lookup_type;
334 DPRINTK("dentry=%p %.*s oz_mode=%d nd->flags=%d",
335 dentry, dentry->d_name.len, dentry->d_name.name, oz_mode,
338 /* If it's our master or we shouldn't trigger a mount we're done */
339 lookup_type = nd->flags & (LOOKUP_CONTINUE | LOOKUP_DIRECTORY);
340 if (oz_mode || !lookup_type)
343 /* If an expire request is pending wait for it. */
344 if (ino && (ino->flags & AUTOFS_INF_EXPIRING)) {
345 DPRINTK("waiting for active request %p name=%.*s",
346 dentry, dentry->d_name.len, dentry->d_name.name);
348 status = autofs4_wait(sbi, dentry, NFY_NONE);
350 DPRINTK("request done status=%d", status);
354 * If the dentry contains directories then it is an
355 * autofs multi-mount with no root mount offset. So
356 * don't try to mount it again.
358 spin_lock(&dcache_lock);
359 if (!d_mountpoint(dentry) && __simple_empty(dentry)) {
360 spin_unlock(&dcache_lock);
362 status = try_to_fill_dentry(dentry, 0);
367 * The mount succeeded but if there is no root mount
368 * it must be an autofs multi-mount with no root offset
369 * so we don't need to follow the mount.
371 if (d_mountpoint(dentry)) {
372 if (!autofs4_follow_mount(&nd->mnt, &nd->dentry)) {
380 spin_unlock(&dcache_lock);
387 return ERR_PTR(status);
391 * Revalidate is called on every cache lookup. Some of those
392 * cache lookups may actually happen while the dentry is not
393 * yet completely filled in, and revalidate has to delay such
396 static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd)
398 struct inode *dir = dentry->d_parent->d_inode;
399 struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
400 int oz_mode = autofs4_oz_mode(sbi);
401 int flags = nd ? nd->flags : 0;
405 if (autofs4_ispending(dentry)) {
406 /* The daemon never causes a mount to trigger */
411 * A zero status is success otherwise we have a
412 * negative error code.
414 status = try_to_fill_dentry(dentry, flags);
419 * A status of EAGAIN here means that the dentry has gone
420 * away while waiting for an expire to complete. If we are
421 * racing with expire lookup will wait for it so this must
422 * be a revalidate and we need to send it to lookup.
424 if (status == -EAGAIN)
430 /* Negative dentry.. invalidate if "old" */
431 if (dentry->d_inode == NULL)
434 /* Check for a non-mountpoint directory with no contents */
435 spin_lock(&dcache_lock);
436 if (S_ISDIR(dentry->d_inode->i_mode) &&
437 !d_mountpoint(dentry) &&
438 __simple_empty(dentry)) {
439 DPRINTK("dentry=%p %.*s, emptydir",
440 dentry, dentry->d_name.len, dentry->d_name.name);
441 spin_unlock(&dcache_lock);
442 /* The daemon never causes a mount to trigger */
447 * A zero status is success otherwise we have a
448 * negative error code.
450 status = try_to_fill_dentry(dentry, flags);
456 spin_unlock(&dcache_lock);
461 void autofs4_dentry_release(struct dentry *de)
463 struct autofs_info *inf;
465 DPRINTK("releasing %p", de);
467 inf = autofs4_dentry_ino(de);
471 struct autofs_sb_info *sbi = autofs4_sbi(de->d_sb);
477 spin_lock(&sbi->rehash_lock);
478 if (!list_empty(&inf->rehash))
479 list_del(&inf->rehash);
480 spin_unlock(&sbi->rehash_lock);
483 autofs4_free_ino(inf);
487 /* For dentries of directories in the root dir */
488 static struct dentry_operations autofs4_root_dentry_operations = {
489 .d_revalidate = autofs4_revalidate,
490 .d_release = autofs4_dentry_release,
493 /* For other dentries */
494 static struct dentry_operations autofs4_dentry_operations = {
495 .d_revalidate = autofs4_revalidate,
496 .d_release = autofs4_dentry_release,
499 static struct dentry *autofs4_lookup_unhashed(struct autofs_sb_info *sbi, struct dentry *parent, struct qstr *name)
501 unsigned int len = name->len;
502 unsigned int hash = name->hash;
503 const unsigned char *str = name->name;
504 struct list_head *p, *head;
506 spin_lock(&dcache_lock);
507 spin_lock(&sbi->rehash_lock);
508 head = &sbi->rehash_list;
509 list_for_each(p, head) {
510 struct autofs_info *ino;
511 struct dentry *dentry;
514 ino = list_entry(p, struct autofs_info, rehash);
515 dentry = ino->dentry;
517 spin_lock(&dentry->d_lock);
519 /* Bad luck, we've already been dentry_iput */
520 if (!dentry->d_inode)
523 qstr = &dentry->d_name;
525 if (dentry->d_name.hash != hash)
527 if (dentry->d_parent != parent)
530 if (qstr->len != len)
532 if (memcmp(qstr->name, str, len))
535 if (d_unhashed(dentry)) {
536 struct autofs_info *ino = autofs4_dentry_ino(dentry);
537 struct inode *inode = dentry->d_inode;
539 list_del_init(&ino->rehash);
542 * Make the rehashed dentry negative so the VFS
543 * behaves as it should.
546 dentry->d_inode = NULL;
547 list_del_init(&dentry->d_alias);
548 spin_unlock(&dentry->d_lock);
549 spin_unlock(&sbi->rehash_lock);
550 spin_unlock(&dcache_lock);
554 spin_unlock(&dentry->d_lock);
555 spin_unlock(&sbi->rehash_lock);
556 spin_unlock(&dcache_lock);
560 spin_unlock(&dentry->d_lock);
562 spin_unlock(&sbi->rehash_lock);
563 spin_unlock(&dcache_lock);
568 /* Lookups in the root directory */
569 static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
571 struct autofs_sb_info *sbi;
572 struct dentry *unhashed;
575 DPRINTK("name = %.*s",
576 dentry->d_name.len, dentry->d_name.name);
578 /* File name too long to exist */
579 if (dentry->d_name.len > NAME_MAX)
580 return ERR_PTR(-ENAMETOOLONG);
582 sbi = autofs4_sbi(dir->i_sb);
583 oz_mode = autofs4_oz_mode(sbi);
585 DPRINTK("pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d",
586 current->pid, process_group(current), sbi->catatonic, oz_mode);
588 unhashed = autofs4_lookup_unhashed(sbi, dentry->d_parent, &dentry->d_name);
591 * Mark the dentry incomplete, but add it. This is needed so
592 * that the VFS layer knows about the dentry, and we can count
593 * on catching any lookups through the revalidate.
595 * Let all the hard work be done by the revalidate function that
596 * needs to be able to do this anyway..
598 * We need to do this before we release the directory semaphore.
600 dentry->d_op = &autofs4_root_dentry_operations;
602 dentry->d_fsdata = NULL;
605 struct autofs_info *ino = autofs4_dentry_ino(unhashed);
606 DPRINTK("rehash %p with %p", dentry, unhashed);
608 * If we are racing with expire the request might not
609 * be quite complete but the directory has been removed
610 * so it must have been successful, so just wait for it.
612 if (ino && (ino->flags & AUTOFS_INF_EXPIRING)) {
613 DPRINTK("wait for incomplete expire %p name=%.*s",
614 unhashed, unhashed->d_name.len,
615 unhashed->d_name.name);
616 autofs4_wait(sbi, unhashed, NFY_NONE);
617 DPRINTK("request completed");
624 spin_lock(&dentry->d_lock);
625 dentry->d_flags |= DCACHE_AUTOFS_PENDING;
626 spin_unlock(&dentry->d_lock);
629 if (dentry->d_op && dentry->d_op->d_revalidate) {
630 mutex_unlock(&dir->i_mutex);
631 (dentry->d_op->d_revalidate)(dentry, nd);
632 mutex_lock(&dir->i_mutex);
636 * If we are still pending, check if we had to handle
637 * a signal. If so we can force a restart..
639 if (dentry->d_flags & DCACHE_AUTOFS_PENDING) {
640 /* See if we were interrupted */
641 if (signal_pending(current)) {
642 sigset_t *sigset = ¤t->pending.signal;
643 if (sigismember (sigset, SIGKILL) ||
644 sigismember (sigset, SIGQUIT) ||
645 sigismember (sigset, SIGINT)) {
648 return ERR_PTR(-ERESTARTNOINTR);
651 spin_lock(&dentry->d_lock);
652 dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
653 spin_unlock(&dentry->d_lock);
657 * If this dentry is unhashed, then we shouldn't honour this
658 * lookup even if the dentry is positive. Returning ENOENT here
659 * doesn't do the right thing for all system calls, but it should
660 * be OK for the operations we permit from an autofs.
662 if (dentry->d_inode && d_unhashed(dentry)) {
665 return ERR_PTR(-ENOENT);
674 static int autofs4_dir_symlink(struct inode *dir,
675 struct dentry *dentry,
678 struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
679 struct autofs_info *ino = autofs4_dentry_ino(dentry);
680 struct autofs_info *p_ino;
684 DPRINTK("%s <- %.*s", symname,
685 dentry->d_name.len, dentry->d_name.name);
687 if (!autofs4_oz_mode(sbi))
690 ino = autofs4_init_ino(ino, sbi, S_IFLNK | 0555);
694 ino->size = strlen(symname);
695 ino->u.symlink = cp = kmalloc(ino->size + 1, GFP_KERNEL);
704 inode = autofs4_get_inode(dir->i_sb, ino);
705 d_instantiate(dentry, inode);
707 if (dir == dir->i_sb->s_root->d_inode)
708 dentry->d_op = &autofs4_root_dentry_operations;
710 dentry->d_op = &autofs4_dentry_operations;
712 dentry->d_fsdata = ino;
713 ino->dentry = dget(dentry);
714 atomic_inc(&ino->count);
715 p_ino = autofs4_dentry_ino(dentry->d_parent);
716 if (p_ino && dentry->d_parent != dentry)
717 atomic_inc(&p_ino->count);
720 dir->i_mtime = CURRENT_TIME;
728 * Normal filesystems would do a "d_delete()" to tell the VFS dcache
729 * that the file no longer exists. However, doing that means that the
730 * VFS layer can turn the dentry into a negative dentry. We don't want
731 * this, because the unlink is probably the result of an expire.
732 * We simply d_drop it and add it to a rehash candidates list in the
733 * super block, which allows the dentry lookup to reuse it retaining
734 * the flags, such as expire in progress, in case we're racing with expire.
736 * If a process is blocked on the dentry waiting for the expire to finish,
737 * it will invalidate the dentry and try to mount with a new one.
739 * Also see autofs4_dir_rmdir()..
741 static int autofs4_dir_unlink(struct inode *dir, struct dentry *dentry)
743 struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
744 struct autofs_info *ino = autofs4_dentry_ino(dentry);
745 struct autofs_info *p_ino;
747 /* This allows root to remove symlinks */
748 if ( !autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN) )
751 if (atomic_dec_and_test(&ino->count)) {
752 p_ino = autofs4_dentry_ino(dentry->d_parent);
753 if (p_ino && dentry->d_parent != dentry)
754 atomic_dec(&p_ino->count);
758 dentry->d_inode->i_size = 0;
759 clear_nlink(dentry->d_inode);
761 dir->i_mtime = CURRENT_TIME;
763 spin_lock(&dcache_lock);
764 spin_lock(&sbi->rehash_lock);
765 list_add(&ino->rehash, &sbi->rehash_list);
766 spin_unlock(&sbi->rehash_lock);
767 spin_lock(&dentry->d_lock);
769 spin_unlock(&dentry->d_lock);
770 spin_unlock(&dcache_lock);
775 static int autofs4_dir_rmdir(struct inode *dir, struct dentry *dentry)
777 struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
778 struct autofs_info *ino = autofs4_dentry_ino(dentry);
779 struct autofs_info *p_ino;
781 DPRINTK("dentry %p, removing %.*s",
782 dentry, dentry->d_name.len, dentry->d_name.name);
784 if (!autofs4_oz_mode(sbi))
787 spin_lock(&dcache_lock);
788 if (!list_empty(&dentry->d_subdirs)) {
789 spin_unlock(&dcache_lock);
792 spin_lock(&sbi->rehash_lock);
793 list_add(&ino->rehash, &sbi->rehash_list);
794 spin_unlock(&sbi->rehash_lock);
795 spin_lock(&dentry->d_lock);
797 spin_unlock(&dentry->d_lock);
798 spin_unlock(&dcache_lock);
800 if (atomic_dec_and_test(&ino->count)) {
801 p_ino = autofs4_dentry_ino(dentry->d_parent);
802 if (p_ino && dentry->d_parent != dentry)
803 atomic_dec(&p_ino->count);
806 dentry->d_inode->i_size = 0;
807 clear_nlink(dentry->d_inode);
815 static int autofs4_dir_mkdir(struct inode *dir, struct dentry *dentry, int mode)
817 struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
818 struct autofs_info *ino = autofs4_dentry_ino(dentry);
819 struct autofs_info *p_ino;
822 if ( !autofs4_oz_mode(sbi) )
825 DPRINTK("dentry %p, creating %.*s",
826 dentry, dentry->d_name.len, dentry->d_name.name);
828 ino = autofs4_init_ino(ino, sbi, S_IFDIR | 0555);
832 inode = autofs4_get_inode(dir->i_sb, ino);
833 d_instantiate(dentry, inode);
835 if (dir == dir->i_sb->s_root->d_inode)
836 dentry->d_op = &autofs4_root_dentry_operations;
838 dentry->d_op = &autofs4_dentry_operations;
840 dentry->d_fsdata = ino;
841 ino->dentry = dget(dentry);
842 atomic_inc(&ino->count);
843 p_ino = autofs4_dentry_ino(dentry->d_parent);
844 if (p_ino && dentry->d_parent != dentry)
845 atomic_inc(&p_ino->count);
848 dir->i_mtime = CURRENT_TIME;
853 /* Get/set timeout ioctl() operation */
854 static inline int autofs4_get_set_timeout(struct autofs_sb_info *sbi,
855 unsigned long __user *p)
858 unsigned long ntimeout;
860 if ( (rv = get_user(ntimeout, p)) ||
861 (rv = put_user(sbi->exp_timeout/HZ, p)) )
864 if ( ntimeout > ULONG_MAX/HZ )
865 sbi->exp_timeout = 0;
867 sbi->exp_timeout = ntimeout * HZ;
872 /* Return protocol version */
873 static inline int autofs4_get_protover(struct autofs_sb_info *sbi, int __user *p)
875 return put_user(sbi->version, p);
878 /* Return protocol sub version */
879 static inline int autofs4_get_protosubver(struct autofs_sb_info *sbi, int __user *p)
881 return put_user(sbi->sub_version, p);
885 * Tells the daemon whether we need to reghost or not. Also, clears
886 * the reghost_needed flag.
888 static inline int autofs4_ask_reghost(struct autofs_sb_info *sbi, int __user *p)
892 DPRINTK("returning %d", sbi->needs_reghost);
894 status = put_user(sbi->needs_reghost, p);
898 sbi->needs_reghost = 0;
903 * Enable / Disable reghosting ioctl() operation
905 static inline int autofs4_toggle_reghost(struct autofs_sb_info *sbi, int __user *p)
910 status = get_user(val, p);
912 DPRINTK("reghost = %d", val);
917 /* turn on/off reghosting, with the val */
918 sbi->reghost_enabled = val;
923 * Tells the daemon whether it can umount the autofs mount.
925 static inline int autofs4_ask_umount(struct vfsmount *mnt, int __user *p)
932 DPRINTK("returning %d", status);
934 status = put_user(status, p);
939 /* Identify autofs4_dentries - this is so we can tell if there's
940 an extra dentry refcount or not. We only hold a refcount on the
941 dentry if its non-negative (ie, d_inode != NULL)
943 int is_autofs4_dentry(struct dentry *dentry)
945 return dentry && dentry->d_inode &&
946 (dentry->d_op == &autofs4_root_dentry_operations ||
947 dentry->d_op == &autofs4_dentry_operations) &&
948 dentry->d_fsdata != NULL;
952 * ioctl()'s on the root directory is the chief method for the daemon to
953 * generate kernel reactions
955 static int autofs4_root_ioctl(struct inode *inode, struct file *filp,
956 unsigned int cmd, unsigned long arg)
958 struct autofs_sb_info *sbi = autofs4_sbi(inode->i_sb);
959 void __user *p = (void __user *)arg;
961 DPRINTK("cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u",
962 cmd,arg,sbi,process_group(current));
964 if ( _IOC_TYPE(cmd) != _IOC_TYPE(AUTOFS_IOC_FIRST) ||
965 _IOC_NR(cmd) - _IOC_NR(AUTOFS_IOC_FIRST) >= AUTOFS_IOC_COUNT )
968 if ( !autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN) )
972 case AUTOFS_IOC_READY: /* Wait queue: go ahead and retry */
973 return autofs4_wait_release(sbi,(autofs_wqt_t)arg,0);
974 case AUTOFS_IOC_FAIL: /* Wait queue: fail with ENOENT */
975 return autofs4_wait_release(sbi,(autofs_wqt_t)arg,-ENOENT);
976 case AUTOFS_IOC_CATATONIC: /* Enter catatonic mode (daemon shutdown) */
977 autofs4_catatonic_mode(sbi);
979 case AUTOFS_IOC_PROTOVER: /* Get protocol version */
980 return autofs4_get_protover(sbi, p);
981 case AUTOFS_IOC_PROTOSUBVER: /* Get protocol sub version */
982 return autofs4_get_protosubver(sbi, p);
983 case AUTOFS_IOC_SETTIMEOUT:
984 return autofs4_get_set_timeout(sbi, p);
986 case AUTOFS_IOC_TOGGLEREGHOST:
987 return autofs4_toggle_reghost(sbi, p);
988 case AUTOFS_IOC_ASKREGHOST:
989 return autofs4_ask_reghost(sbi, p);
991 case AUTOFS_IOC_ASKUMOUNT:
992 return autofs4_ask_umount(filp->f_path.mnt, p);
994 /* return a single thing to expire */
995 case AUTOFS_IOC_EXPIRE:
996 return autofs4_expire_run(inode->i_sb,filp->f_path.mnt,sbi, p);
997 /* same as above, but can send multiple expires through pipe */
998 case AUTOFS_IOC_EXPIRE_MULTI:
999 return autofs4_expire_multi(inode->i_sb,filp->f_path.mnt,sbi, p);