xfs: fix type usage
[linux/fpc-iii.git] / fs / autofs4 / root.c
blobd79ced9258614010128dd8f1ed6a0cff2b525f21
1 /*
2 * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
3 * Copyright 1999-2000 Jeremy Fitzhardinge <jeremy@goop.org>
4 * Copyright 2001-2006 Ian Kent <raven@themaw.net>
6 * This file is part of the Linux kernel and is made available under
7 * the terms of the GNU General Public License, version 2, or at your
8 * option, any later version, incorporated herein by reference.
9 */
11 #include <linux/capability.h>
12 #include <linux/errno.h>
13 #include <linux/stat.h>
14 #include <linux/slab.h>
15 #include <linux/param.h>
16 #include <linux/time.h>
17 #include <linux/compat.h>
18 #include <linux/mutex.h>
20 #include "autofs_i.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 *, umode_t);
26 static long autofs4_root_ioctl(struct file *, unsigned int, unsigned long);
27 #ifdef CONFIG_COMPAT
28 static long autofs4_root_compat_ioctl(struct file *,
29 unsigned int, unsigned long);
30 #endif
31 static int autofs4_dir_open(struct inode *inode, struct file *file);
32 static struct dentry *autofs4_lookup(struct inode *,
33 struct dentry *, unsigned int);
34 static struct vfsmount *autofs4_d_automount(struct path *);
35 static int autofs4_d_manage(const struct path *, bool);
36 static void autofs4_dentry_release(struct dentry *);
38 const struct file_operations autofs4_root_operations = {
39 .open = dcache_dir_open,
40 .release = dcache_dir_close,
41 .read = generic_read_dir,
42 .iterate_shared = dcache_readdir,
43 .llseek = dcache_dir_lseek,
44 .unlocked_ioctl = autofs4_root_ioctl,
45 #ifdef CONFIG_COMPAT
46 .compat_ioctl = autofs4_root_compat_ioctl,
47 #endif
50 const struct file_operations autofs4_dir_operations = {
51 .open = autofs4_dir_open,
52 .release = dcache_dir_close,
53 .read = generic_read_dir,
54 .iterate_shared = dcache_readdir,
55 .llseek = dcache_dir_lseek,
58 const struct inode_operations autofs4_dir_inode_operations = {
59 .lookup = autofs4_lookup,
60 .unlink = autofs4_dir_unlink,
61 .symlink = autofs4_dir_symlink,
62 .mkdir = autofs4_dir_mkdir,
63 .rmdir = autofs4_dir_rmdir,
66 const struct dentry_operations autofs4_dentry_operations = {
67 .d_automount = autofs4_d_automount,
68 .d_manage = autofs4_d_manage,
69 .d_release = autofs4_dentry_release,
72 static void autofs4_add_active(struct dentry *dentry)
74 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
75 struct autofs_info *ino;
77 ino = autofs4_dentry_ino(dentry);
78 if (ino) {
79 spin_lock(&sbi->lookup_lock);
80 if (!ino->active_count) {
81 if (list_empty(&ino->active))
82 list_add(&ino->active, &sbi->active_list);
84 ino->active_count++;
85 spin_unlock(&sbi->lookup_lock);
89 static void autofs4_del_active(struct dentry *dentry)
91 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
92 struct autofs_info *ino;
94 ino = autofs4_dentry_ino(dentry);
95 if (ino) {
96 spin_lock(&sbi->lookup_lock);
97 ino->active_count--;
98 if (!ino->active_count) {
99 if (!list_empty(&ino->active))
100 list_del_init(&ino->active);
102 spin_unlock(&sbi->lookup_lock);
106 static int autofs4_dir_open(struct inode *inode, struct file *file)
108 struct dentry *dentry = file->f_path.dentry;
109 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
111 pr_debug("file=%p dentry=%p %pd\n", file, dentry, dentry);
113 if (autofs4_oz_mode(sbi))
114 goto out;
117 * An empty directory in an autofs file system is always a
118 * mount point. The daemon must have failed to mount this
119 * during lookup so it doesn't exist. This can happen, for
120 * example, if user space returns an incorrect status for a
121 * mount request. Otherwise we're doing a readdir on the
122 * autofs file system so just let the libfs routines handle
123 * it.
125 spin_lock(&sbi->lookup_lock);
126 if (!path_is_mountpoint(&file->f_path) && simple_empty(dentry)) {
127 spin_unlock(&sbi->lookup_lock);
128 return -ENOENT;
130 spin_unlock(&sbi->lookup_lock);
132 out:
133 return dcache_dir_open(inode, file);
136 static void autofs4_dentry_release(struct dentry *de)
138 struct autofs_info *ino = autofs4_dentry_ino(de);
139 struct autofs_sb_info *sbi = autofs4_sbi(de->d_sb);
141 pr_debug("releasing %p\n", de);
143 if (!ino)
144 return;
146 if (sbi) {
147 spin_lock(&sbi->lookup_lock);
148 if (!list_empty(&ino->active))
149 list_del(&ino->active);
150 if (!list_empty(&ino->expiring))
151 list_del(&ino->expiring);
152 spin_unlock(&sbi->lookup_lock);
155 autofs4_free_ino(ino);
158 static struct dentry *autofs4_lookup_active(struct dentry *dentry)
160 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
161 struct dentry *parent = dentry->d_parent;
162 const struct qstr *name = &dentry->d_name;
163 unsigned int len = name->len;
164 unsigned int hash = name->hash;
165 const unsigned char *str = name->name;
166 struct list_head *p, *head;
168 head = &sbi->active_list;
169 if (list_empty(head))
170 return NULL;
171 spin_lock(&sbi->lookup_lock);
172 list_for_each(p, head) {
173 struct autofs_info *ino;
174 struct dentry *active;
175 const struct qstr *qstr;
177 ino = list_entry(p, struct autofs_info, active);
178 active = ino->dentry;
180 spin_lock(&active->d_lock);
182 /* Already gone? */
183 if ((int) d_count(active) <= 0)
184 goto next;
186 qstr = &active->d_name;
188 if (active->d_name.hash != hash)
189 goto next;
190 if (active->d_parent != parent)
191 goto next;
193 if (qstr->len != len)
194 goto next;
195 if (memcmp(qstr->name, str, len))
196 goto next;
198 if (d_unhashed(active)) {
199 dget_dlock(active);
200 spin_unlock(&active->d_lock);
201 spin_unlock(&sbi->lookup_lock);
202 return active;
204 next:
205 spin_unlock(&active->d_lock);
207 spin_unlock(&sbi->lookup_lock);
209 return NULL;
212 static struct dentry *autofs4_lookup_expiring(struct dentry *dentry,
213 bool rcu_walk)
215 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
216 struct dentry *parent = dentry->d_parent;
217 const struct qstr *name = &dentry->d_name;
218 unsigned int len = name->len;
219 unsigned int hash = name->hash;
220 const unsigned char *str = name->name;
221 struct list_head *p, *head;
223 head = &sbi->expiring_list;
224 if (list_empty(head))
225 return NULL;
226 spin_lock(&sbi->lookup_lock);
227 list_for_each(p, head) {
228 struct autofs_info *ino;
229 struct dentry *expiring;
230 const struct qstr *qstr;
232 if (rcu_walk) {
233 spin_unlock(&sbi->lookup_lock);
234 return ERR_PTR(-ECHILD);
237 ino = list_entry(p, struct autofs_info, expiring);
238 expiring = ino->dentry;
240 spin_lock(&expiring->d_lock);
242 /* We've already been dentry_iput or unlinked */
243 if (d_really_is_negative(expiring))
244 goto next;
246 qstr = &expiring->d_name;
248 if (expiring->d_name.hash != hash)
249 goto next;
250 if (expiring->d_parent != parent)
251 goto next;
253 if (qstr->len != len)
254 goto next;
255 if (memcmp(qstr->name, str, len))
256 goto next;
258 if (d_unhashed(expiring)) {
259 dget_dlock(expiring);
260 spin_unlock(&expiring->d_lock);
261 spin_unlock(&sbi->lookup_lock);
262 return expiring;
264 next:
265 spin_unlock(&expiring->d_lock);
267 spin_unlock(&sbi->lookup_lock);
269 return NULL;
272 static int autofs4_mount_wait(const struct path *path, bool rcu_walk)
274 struct autofs_sb_info *sbi = autofs4_sbi(path->dentry->d_sb);
275 struct autofs_info *ino = autofs4_dentry_ino(path->dentry);
276 int status = 0;
278 if (ino->flags & AUTOFS_INF_PENDING) {
279 if (rcu_walk)
280 return -ECHILD;
281 pr_debug("waiting for mount name=%pd\n", path->dentry);
282 status = autofs4_wait(sbi, path, NFY_MOUNT);
283 pr_debug("mount wait done status=%d\n", status);
284 ino->last_used = jiffies;
286 return status;
289 static int do_expire_wait(const struct path *path, bool rcu_walk)
291 struct dentry *dentry = path->dentry;
292 struct dentry *expiring;
294 expiring = autofs4_lookup_expiring(dentry, rcu_walk);
295 if (IS_ERR(expiring))
296 return PTR_ERR(expiring);
297 if (!expiring)
298 return autofs4_expire_wait(path, rcu_walk);
299 else {
300 const struct path this = { .mnt = path->mnt, .dentry = expiring };
302 * If we are racing with expire the request might not
303 * be quite complete, but the directory has been removed
304 * so it must have been successful, just wait for it.
306 autofs4_expire_wait(&this, 0);
307 autofs4_del_expiring(expiring);
308 dput(expiring);
310 return 0;
313 static struct dentry *autofs4_mountpoint_changed(struct path *path)
315 struct dentry *dentry = path->dentry;
316 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
319 * If this is an indirect mount the dentry could have gone away
320 * as a result of an expire and a new one created.
322 if (autofs_type_indirect(sbi->type) && d_unhashed(dentry)) {
323 struct dentry *parent = dentry->d_parent;
324 struct dentry *new;
326 new = d_lookup(parent, &dentry->d_name);
327 if (!new)
328 return NULL;
329 if (new == dentry)
330 dput(new);
331 else {
332 struct autofs_info *ino;
334 ino = autofs4_dentry_ino(new);
335 ino->last_used = jiffies;
336 dput(path->dentry);
337 path->dentry = new;
340 return path->dentry;
343 static struct vfsmount *autofs4_d_automount(struct path *path)
345 struct dentry *dentry = path->dentry;
346 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
347 struct autofs_info *ino = autofs4_dentry_ino(dentry);
348 int status;
350 pr_debug("dentry=%p %pd\n", dentry, dentry);
352 /* The daemon never triggers a mount. */
353 if (autofs4_oz_mode(sbi))
354 return NULL;
357 * If an expire request is pending everyone must wait.
358 * If the expire fails we're still mounted so continue
359 * the follow and return. A return of -EAGAIN (which only
360 * happens with indirect mounts) means the expire completed
361 * and the directory was removed, so just go ahead and try
362 * the mount.
364 status = do_expire_wait(path, 0);
365 if (status && status != -EAGAIN)
366 return NULL;
368 /* Callback to the daemon to perform the mount or wait */
369 spin_lock(&sbi->fs_lock);
370 if (ino->flags & AUTOFS_INF_PENDING) {
371 spin_unlock(&sbi->fs_lock);
372 status = autofs4_mount_wait(path, 0);
373 if (status)
374 return ERR_PTR(status);
375 goto done;
379 * If the dentry is a symlink it's equivalent to a directory
380 * having path_is_mountpoint() true, so there's no need to call
381 * back to the daemon.
383 if (d_really_is_positive(dentry) && d_is_symlink(dentry)) {
384 spin_unlock(&sbi->fs_lock);
385 goto done;
388 if (!path_is_mountpoint(path)) {
390 * It's possible that user space hasn't removed directories
391 * after umounting a rootless multi-mount, although it
392 * should. For v5 path_has_submounts() is sufficient to
393 * handle this because the leaves of the directory tree under
394 * the mount never trigger mounts themselves (they have an
395 * autofs trigger mount mounted on them). But v4 pseudo direct
396 * mounts do need the leaves to trigger mounts. In this case
397 * we have no choice but to use the list_empty() check and
398 * require user space behave.
400 if (sbi->version > 4) {
401 if (path_has_submounts(path)) {
402 spin_unlock(&sbi->fs_lock);
403 goto done;
405 } else {
406 if (!simple_empty(dentry)) {
407 spin_unlock(&sbi->fs_lock);
408 goto done;
411 ino->flags |= AUTOFS_INF_PENDING;
412 spin_unlock(&sbi->fs_lock);
413 status = autofs4_mount_wait(path, 0);
414 spin_lock(&sbi->fs_lock);
415 ino->flags &= ~AUTOFS_INF_PENDING;
416 if (status) {
417 spin_unlock(&sbi->fs_lock);
418 return ERR_PTR(status);
421 spin_unlock(&sbi->fs_lock);
422 done:
423 /* Mount succeeded, check if we ended up with a new dentry */
424 dentry = autofs4_mountpoint_changed(path);
425 if (!dentry)
426 return ERR_PTR(-ENOENT);
428 return NULL;
431 static int autofs4_d_manage(const struct path *path, bool rcu_walk)
433 struct dentry *dentry = path->dentry;
434 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
435 struct autofs_info *ino = autofs4_dentry_ino(dentry);
436 int status;
438 pr_debug("dentry=%p %pd\n", dentry, dentry);
440 /* The daemon never waits. */
441 if (autofs4_oz_mode(sbi)) {
442 if (!path_is_mountpoint(path))
443 return -EISDIR;
444 return 0;
447 /* Wait for pending expires */
448 if (do_expire_wait(path, rcu_walk) == -ECHILD)
449 return -ECHILD;
452 * This dentry may be under construction so wait on mount
453 * completion.
455 status = autofs4_mount_wait(path, rcu_walk);
456 if (status)
457 return status;
459 if (rcu_walk) {
460 /* We don't need fs_lock in rcu_walk mode,
461 * just testing 'AUTOFS_INFO_NO_RCU' is enough.
462 * simple_empty() takes a spinlock, so leave it
463 * to last.
464 * We only return -EISDIR when certain this isn't
465 * a mount-trap.
467 struct inode *inode;
469 if (ino->flags & AUTOFS_INF_WANT_EXPIRE)
470 return 0;
471 if (path_is_mountpoint(path))
472 return 0;
473 inode = d_inode_rcu(dentry);
474 if (inode && S_ISLNK(inode->i_mode))
475 return -EISDIR;
476 if (list_empty(&dentry->d_subdirs))
477 return 0;
478 if (!simple_empty(dentry))
479 return -EISDIR;
480 return 0;
483 spin_lock(&sbi->fs_lock);
485 * If the dentry has been selected for expire while we slept
486 * on the lock then it might go away. We'll deal with that in
487 * ->d_automount() and wait on a new mount if the expire
488 * succeeds or return here if it doesn't (since there's no
489 * mount to follow with a rootless multi-mount).
491 if (!(ino->flags & AUTOFS_INF_EXPIRING)) {
493 * Any needed mounting has been completed and the path
494 * updated so check if this is a rootless multi-mount so
495 * we can avoid needless calls ->d_automount() and avoid
496 * an incorrect ELOOP error return.
498 if ((!path_is_mountpoint(path) && !simple_empty(dentry)) ||
499 (d_really_is_positive(dentry) && d_is_symlink(dentry)))
500 status = -EISDIR;
502 spin_unlock(&sbi->fs_lock);
504 return status;
507 /* Lookups in the root directory */
508 static struct dentry *autofs4_lookup(struct inode *dir,
509 struct dentry *dentry, unsigned int flags)
511 struct autofs_sb_info *sbi;
512 struct autofs_info *ino;
513 struct dentry *active;
515 pr_debug("name = %pd\n", dentry);
517 /* File name too long to exist */
518 if (dentry->d_name.len > NAME_MAX)
519 return ERR_PTR(-ENAMETOOLONG);
521 sbi = autofs4_sbi(dir->i_sb);
523 pr_debug("pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d\n",
524 current->pid, task_pgrp_nr(current), sbi->catatonic,
525 autofs4_oz_mode(sbi));
527 active = autofs4_lookup_active(dentry);
528 if (active)
529 return active;
530 else {
532 * A dentry that is not within the root can never trigger a
533 * mount operation, unless the directory already exists, so we
534 * can return fail immediately. The daemon however does need
535 * to create directories within the file system.
537 if (!autofs4_oz_mode(sbi) && !IS_ROOT(dentry->d_parent))
538 return ERR_PTR(-ENOENT);
540 /* Mark entries in the root as mount triggers */
541 if (IS_ROOT(dentry->d_parent) &&
542 autofs_type_indirect(sbi->type))
543 __managed_dentry_set_managed(dentry);
545 ino = autofs4_new_ino(sbi);
546 if (!ino)
547 return ERR_PTR(-ENOMEM);
549 dentry->d_fsdata = ino;
550 ino->dentry = dentry;
552 autofs4_add_active(dentry);
554 return NULL;
557 static int autofs4_dir_symlink(struct inode *dir,
558 struct dentry *dentry,
559 const char *symname)
561 struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
562 struct autofs_info *ino = autofs4_dentry_ino(dentry);
563 struct autofs_info *p_ino;
564 struct inode *inode;
565 size_t size = strlen(symname);
566 char *cp;
568 pr_debug("%s <- %pd\n", symname, dentry);
570 if (!autofs4_oz_mode(sbi))
571 return -EACCES;
573 BUG_ON(!ino);
575 autofs4_clean_ino(ino);
577 autofs4_del_active(dentry);
579 cp = kmalloc(size + 1, GFP_KERNEL);
580 if (!cp)
581 return -ENOMEM;
583 strcpy(cp, symname);
585 inode = autofs4_get_inode(dir->i_sb, S_IFLNK | 0555);
586 if (!inode) {
587 kfree(cp);
588 return -ENOMEM;
590 inode->i_private = cp;
591 inode->i_size = size;
592 d_add(dentry, inode);
594 dget(dentry);
595 atomic_inc(&ino->count);
596 p_ino = autofs4_dentry_ino(dentry->d_parent);
597 if (p_ino && !IS_ROOT(dentry))
598 atomic_inc(&p_ino->count);
600 dir->i_mtime = current_time(dir);
602 return 0;
606 * NOTE!
608 * Normal filesystems would do a "d_delete()" to tell the VFS dcache
609 * that the file no longer exists. However, doing that means that the
610 * VFS layer can turn the dentry into a negative dentry. We don't want
611 * this, because the unlink is probably the result of an expire.
612 * We simply d_drop it and add it to a expiring list in the super block,
613 * which allows the dentry lookup to check for an incomplete expire.
615 * If a process is blocked on the dentry waiting for the expire to finish,
616 * it will invalidate the dentry and try to mount with a new one.
618 * Also see autofs4_dir_rmdir()..
620 static int autofs4_dir_unlink(struct inode *dir, struct dentry *dentry)
622 struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
623 struct autofs_info *ino = autofs4_dentry_ino(dentry);
624 struct autofs_info *p_ino;
626 /* This allows root to remove symlinks */
627 if (!autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN))
628 return -EPERM;
630 if (atomic_dec_and_test(&ino->count)) {
631 p_ino = autofs4_dentry_ino(dentry->d_parent);
632 if (p_ino && !IS_ROOT(dentry))
633 atomic_dec(&p_ino->count);
635 dput(ino->dentry);
637 d_inode(dentry)->i_size = 0;
638 clear_nlink(d_inode(dentry));
640 dir->i_mtime = current_time(dir);
642 spin_lock(&sbi->lookup_lock);
643 __autofs4_add_expiring(dentry);
644 d_drop(dentry);
645 spin_unlock(&sbi->lookup_lock);
647 return 0;
651 * Version 4 of autofs provides a pseudo direct mount implementation
652 * that relies on directories at the leaves of a directory tree under
653 * an indirect mount to trigger mounts. To allow for this we need to
654 * set the DMANAGED_AUTOMOUNT and DMANAGED_TRANSIT flags on the leaves
655 * of the directory tree. There is no need to clear the automount flag
656 * following a mount or restore it after an expire because these mounts
657 * are always covered. However, it is necessary to ensure that these
658 * flags are clear on non-empty directories to avoid unnecessary calls
659 * during path walks.
661 static void autofs_set_leaf_automount_flags(struct dentry *dentry)
663 struct dentry *parent;
665 /* root and dentrys in the root are already handled */
666 if (IS_ROOT(dentry->d_parent))
667 return;
669 managed_dentry_set_managed(dentry);
671 parent = dentry->d_parent;
672 /* only consider parents below dentrys in the root */
673 if (IS_ROOT(parent->d_parent))
674 return;
675 managed_dentry_clear_managed(parent);
678 static void autofs_clear_leaf_automount_flags(struct dentry *dentry)
680 struct list_head *d_child;
681 struct dentry *parent;
683 /* flags for dentrys in the root are handled elsewhere */
684 if (IS_ROOT(dentry->d_parent))
685 return;
687 managed_dentry_clear_managed(dentry);
689 parent = dentry->d_parent;
690 /* only consider parents below dentrys in the root */
691 if (IS_ROOT(parent->d_parent))
692 return;
693 d_child = &dentry->d_child;
694 /* Set parent managed if it's becoming empty */
695 if (d_child->next == &parent->d_subdirs &&
696 d_child->prev == &parent->d_subdirs)
697 managed_dentry_set_managed(parent);
700 static int autofs4_dir_rmdir(struct inode *dir, struct dentry *dentry)
702 struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
703 struct autofs_info *ino = autofs4_dentry_ino(dentry);
704 struct autofs_info *p_ino;
706 pr_debug("dentry %p, removing %pd\n", dentry, dentry);
708 if (!autofs4_oz_mode(sbi))
709 return -EACCES;
711 spin_lock(&sbi->lookup_lock);
712 if (!simple_empty(dentry)) {
713 spin_unlock(&sbi->lookup_lock);
714 return -ENOTEMPTY;
716 __autofs4_add_expiring(dentry);
717 d_drop(dentry);
718 spin_unlock(&sbi->lookup_lock);
720 if (sbi->version < 5)
721 autofs_clear_leaf_automount_flags(dentry);
723 if (atomic_dec_and_test(&ino->count)) {
724 p_ino = autofs4_dentry_ino(dentry->d_parent);
725 if (p_ino && dentry->d_parent != dentry)
726 atomic_dec(&p_ino->count);
728 dput(ino->dentry);
729 d_inode(dentry)->i_size = 0;
730 clear_nlink(d_inode(dentry));
732 if (dir->i_nlink)
733 drop_nlink(dir);
735 return 0;
738 static int autofs4_dir_mkdir(struct inode *dir,
739 struct dentry *dentry, umode_t mode)
741 struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
742 struct autofs_info *ino = autofs4_dentry_ino(dentry);
743 struct autofs_info *p_ino;
744 struct inode *inode;
746 if (!autofs4_oz_mode(sbi))
747 return -EACCES;
749 pr_debug("dentry %p, creating %pd\n", dentry, dentry);
751 BUG_ON(!ino);
753 autofs4_clean_ino(ino);
755 autofs4_del_active(dentry);
757 inode = autofs4_get_inode(dir->i_sb, S_IFDIR | 0555);
758 if (!inode)
759 return -ENOMEM;
760 d_add(dentry, inode);
762 if (sbi->version < 5)
763 autofs_set_leaf_automount_flags(dentry);
765 dget(dentry);
766 atomic_inc(&ino->count);
767 p_ino = autofs4_dentry_ino(dentry->d_parent);
768 if (p_ino && !IS_ROOT(dentry))
769 atomic_inc(&p_ino->count);
770 inc_nlink(dir);
771 dir->i_mtime = current_time(dir);
773 return 0;
776 /* Get/set timeout ioctl() operation */
777 #ifdef CONFIG_COMPAT
778 static inline int autofs4_compat_get_set_timeout(struct autofs_sb_info *sbi,
779 compat_ulong_t __user *p)
781 unsigned long ntimeout;
782 int rv;
784 rv = get_user(ntimeout, p);
785 if (rv)
786 goto error;
788 rv = put_user(sbi->exp_timeout/HZ, p);
789 if (rv)
790 goto error;
792 if (ntimeout > UINT_MAX/HZ)
793 sbi->exp_timeout = 0;
794 else
795 sbi->exp_timeout = ntimeout * HZ;
797 return 0;
798 error:
799 return rv;
801 #endif
803 static inline int autofs4_get_set_timeout(struct autofs_sb_info *sbi,
804 unsigned long __user *p)
806 unsigned long ntimeout;
807 int rv;
809 rv = get_user(ntimeout, p);
810 if (rv)
811 goto error;
813 rv = put_user(sbi->exp_timeout/HZ, p);
814 if (rv)
815 goto error;
817 if (ntimeout > ULONG_MAX/HZ)
818 sbi->exp_timeout = 0;
819 else
820 sbi->exp_timeout = ntimeout * HZ;
822 return 0;
823 error:
824 return rv;
827 /* Return protocol version */
828 static inline int autofs4_get_protover(struct autofs_sb_info *sbi,
829 int __user *p)
831 return put_user(sbi->version, p);
834 /* Return protocol sub version */
835 static inline int autofs4_get_protosubver(struct autofs_sb_info *sbi,
836 int __user *p)
838 return put_user(sbi->sub_version, p);
842 * Tells the daemon whether it can umount the autofs mount.
844 static inline int autofs4_ask_umount(struct vfsmount *mnt, int __user *p)
846 int status = 0;
848 if (may_umount(mnt))
849 status = 1;
851 pr_debug("may umount %d\n", status);
853 status = put_user(status, p);
855 return status;
858 /* Identify autofs4_dentries - this is so we can tell if there's
859 * an extra dentry refcount or not. We only hold a refcount on the
860 * dentry if its non-negative (ie, d_inode != NULL)
862 int is_autofs4_dentry(struct dentry *dentry)
864 return dentry && d_really_is_positive(dentry) &&
865 dentry->d_op == &autofs4_dentry_operations &&
866 dentry->d_fsdata != NULL;
870 * ioctl()'s on the root directory is the chief method for the daemon to
871 * generate kernel reactions
873 static int autofs4_root_ioctl_unlocked(struct inode *inode, struct file *filp,
874 unsigned int cmd, unsigned long arg)
876 struct autofs_sb_info *sbi = autofs4_sbi(inode->i_sb);
877 void __user *p = (void __user *)arg;
879 pr_debug("cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u\n",
880 cmd, arg, sbi, task_pgrp_nr(current));
882 if (_IOC_TYPE(cmd) != _IOC_TYPE(AUTOFS_IOC_FIRST) ||
883 _IOC_NR(cmd) - _IOC_NR(AUTOFS_IOC_FIRST) >= AUTOFS_IOC_COUNT)
884 return -ENOTTY;
886 if (!autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN))
887 return -EPERM;
889 switch (cmd) {
890 case AUTOFS_IOC_READY: /* Wait queue: go ahead and retry */
891 return autofs4_wait_release(sbi, (autofs_wqt_t) arg, 0);
892 case AUTOFS_IOC_FAIL: /* Wait queue: fail with ENOENT */
893 return autofs4_wait_release(sbi, (autofs_wqt_t) arg, -ENOENT);
894 case AUTOFS_IOC_CATATONIC: /* Enter catatonic mode (daemon shutdown) */
895 autofs4_catatonic_mode(sbi);
896 return 0;
897 case AUTOFS_IOC_PROTOVER: /* Get protocol version */
898 return autofs4_get_protover(sbi, p);
899 case AUTOFS_IOC_PROTOSUBVER: /* Get protocol sub version */
900 return autofs4_get_protosubver(sbi, p);
901 case AUTOFS_IOC_SETTIMEOUT:
902 return autofs4_get_set_timeout(sbi, p);
903 #ifdef CONFIG_COMPAT
904 case AUTOFS_IOC_SETTIMEOUT32:
905 return autofs4_compat_get_set_timeout(sbi, p);
906 #endif
908 case AUTOFS_IOC_ASKUMOUNT:
909 return autofs4_ask_umount(filp->f_path.mnt, p);
911 /* return a single thing to expire */
912 case AUTOFS_IOC_EXPIRE:
913 return autofs4_expire_run(inode->i_sb,
914 filp->f_path.mnt, sbi, p);
915 /* same as above, but can send multiple expires through pipe */
916 case AUTOFS_IOC_EXPIRE_MULTI:
917 return autofs4_expire_multi(inode->i_sb,
918 filp->f_path.mnt, sbi, p);
920 default:
921 return -EINVAL;
925 static long autofs4_root_ioctl(struct file *filp,
926 unsigned int cmd, unsigned long arg)
928 struct inode *inode = file_inode(filp);
930 return autofs4_root_ioctl_unlocked(inode, filp, cmd, arg);
933 #ifdef CONFIG_COMPAT
934 static long autofs4_root_compat_ioctl(struct file *filp,
935 unsigned int cmd, unsigned long arg)
937 struct inode *inode = file_inode(filp);
938 int ret;
940 if (cmd == AUTOFS_IOC_READY || cmd == AUTOFS_IOC_FAIL)
941 ret = autofs4_root_ioctl_unlocked(inode, filp, cmd, arg);
942 else
943 ret = autofs4_root_ioctl_unlocked(inode, filp, cmd,
944 (unsigned long) compat_ptr(arg));
946 return ret;
948 #endif