blob: ace3eea163f0f17a2dce503bd48838f0282bbb18 [file] [log] [blame]
lh9ed821d2023-04-07 01:36:19 -07001/*
2 * Copyright 2008 Red Hat, Inc. All rights reserved.
3 * Copyright 2008 Ian Kent <raven@themaw.net>
4 *
5 * This file is part of the Linux kernel and is made available under
6 * the terms of the GNU General Public License, version 2, or at your
7 * option, any later version, incorporated herein by reference.
8 */
9
10#include <linux/module.h>
11#include <linux/vmalloc.h>
12#include <linux/miscdevice.h>
13#include <linux/init.h>
14#include <linux/wait.h>
15#include <linux/namei.h>
16#include <linux/fcntl.h>
17#include <linux/file.h>
18#include <linux/fdtable.h>
19#include <linux/sched.h>
20#include <linux/compat.h>
21#include <linux/syscalls.h>
22#include <linux/magic.h>
23#include <linux/dcache.h>
24#include <linux/uaccess.h>
25#include <linux/slab.h>
26
27#include "autofs_i.h"
28
29/*
30 * This module implements an interface for routing autofs ioctl control
31 * commands via a miscellaneous device file.
32 *
33 * The alternate interface is needed because we need to be able open
34 * an ioctl file descriptor on an autofs mount that may be covered by
35 * another mount. This situation arises when starting automount(8)
36 * or other user space daemon which uses direct mounts or offset
37 * mounts (used for autofs lazy mount/umount of nested mount trees),
38 * which have been left busy at at service shutdown.
39 */
40
41#define AUTOFS_DEV_IOCTL_SIZE sizeof(struct autofs_dev_ioctl)
42
43typedef int (*ioctl_fn)(struct file *, struct autofs_sb_info *,
44 struct autofs_dev_ioctl *);
45
46static int check_name(const char *name)
47{
48 if (!strchr(name, '/'))
49 return -EINVAL;
50 return 0;
51}
52
53/*
54 * Check a string doesn't overrun the chunk of
55 * memory we copied from user land.
56 */
57static int invalid_str(char *str, size_t size)
58{
59 if (memchr(str, 0, size))
60 return 0;
61 return -EINVAL;
62}
63
64/*
65 * Check that the user compiled against correct version of autofs
66 * misc device code.
67 *
68 * As well as checking the version compatibility this always copies
69 * the kernel interface version out.
70 */
71static int check_dev_ioctl_version(int cmd, struct autofs_dev_ioctl *param)
72{
73 int err = 0;
74
75 if ((AUTOFS_DEV_IOCTL_VERSION_MAJOR != param->ver_major) ||
76 (AUTOFS_DEV_IOCTL_VERSION_MINOR < param->ver_minor)) {
77 AUTOFS_WARN("ioctl control interface version mismatch: "
78 "kernel(%u.%u), user(%u.%u), cmd(%d)",
79 AUTOFS_DEV_IOCTL_VERSION_MAJOR,
80 AUTOFS_DEV_IOCTL_VERSION_MINOR,
81 param->ver_major, param->ver_minor, cmd);
82 err = -EINVAL;
83 }
84
85 /* Fill in the kernel version. */
86 param->ver_major = AUTOFS_DEV_IOCTL_VERSION_MAJOR;
87 param->ver_minor = AUTOFS_DEV_IOCTL_VERSION_MINOR;
88
89 return err;
90}
91
92/*
93 * Copy parameter control struct, including a possible path allocated
94 * at the end of the struct.
95 */
96static struct autofs_dev_ioctl *copy_dev_ioctl(struct autofs_dev_ioctl __user *in)
97{
98 struct autofs_dev_ioctl tmp, *res;
99
100 if (copy_from_user(&tmp, in, sizeof(tmp)))
101 return ERR_PTR(-EFAULT);
102
103 if (tmp.size < sizeof(tmp))
104 return ERR_PTR(-EINVAL);
105
106 if (tmp.size > (PATH_MAX + sizeof(tmp)))
107 return ERR_PTR(-ENAMETOOLONG);
108
109 res = memdup_user(in, tmp.size);
110 if (!IS_ERR(res))
111 res->size = tmp.size;
112
113 return res;
114}
115
116static inline void free_dev_ioctl(struct autofs_dev_ioctl *param)
117{
118 kfree(param);
119 return;
120}
121
122/*
123 * Check sanity of parameter control fields and if a path is present
124 * check that it is terminated and contains at least one "/".
125 */
126static int validate_dev_ioctl(int cmd, struct autofs_dev_ioctl *param)
127{
128 int err;
129
130 err = check_dev_ioctl_version(cmd, param);
131 if (err) {
132 AUTOFS_WARN("invalid device control module version "
133 "supplied for cmd(0x%08x)", cmd);
134 goto out;
135 }
136
137 if (param->size > sizeof(*param)) {
138 err = invalid_str(param->path, param->size - sizeof(*param));
139 if (err) {
140 AUTOFS_WARN(
141 "path string terminator missing for cmd(0x%08x)",
142 cmd);
143 goto out;
144 }
145
146 err = check_name(param->path);
147 if (err) {
148 AUTOFS_WARN("invalid path supplied for cmd(0x%08x)",
149 cmd);
150 goto out;
151 }
152 }
153
154 err = 0;
155out:
156 return err;
157}
158
159/*
160 * Get the autofs super block info struct from the file opened on
161 * the autofs mount point.
162 */
163static struct autofs_sb_info *autofs_dev_ioctl_sbi(struct file *f)
164{
165 struct autofs_sb_info *sbi = NULL;
166 struct inode *inode;
167
168 if (f) {
169 inode = f->f_path.dentry->d_inode;
170 sbi = autofs4_sbi(inode->i_sb);
171 }
172 return sbi;
173}
174
175/* Return autofs module protocol version */
176static int autofs_dev_ioctl_protover(struct file *fp,
177 struct autofs_sb_info *sbi,
178 struct autofs_dev_ioctl *param)
179{
180 param->protover.version = sbi->version;
181 return 0;
182}
183
184/* Return autofs module protocol sub version */
185static int autofs_dev_ioctl_protosubver(struct file *fp,
186 struct autofs_sb_info *sbi,
187 struct autofs_dev_ioctl *param)
188{
189 param->protosubver.sub_version = sbi->sub_version;
190 return 0;
191}
192
193static int find_autofs_mount(const char *pathname,
194 struct path *res,
195 int test(struct path *path, void *data),
196 void *data)
197{
198 struct path path;
199 int err = kern_path(pathname, 0, &path);
200 if (err)
201 return err;
202 err = -ENOENT;
203 while (path.dentry == path.mnt->mnt_root) {
204 if (path.dentry->d_sb->s_magic == AUTOFS_SUPER_MAGIC) {
205 if (test(&path, data)) {
206 path_get(&path);
207 if (!err) /* already found some */
208 path_put(res);
209 *res = path;
210 err = 0;
211 }
212 }
213 if (!follow_up(&path))
214 break;
215 }
216 path_put(&path);
217 return err;
218}
219
220static int test_by_dev(struct path *path, void *p)
221{
222 return path->dentry->d_sb->s_dev == *(dev_t *)p;
223}
224
225static int test_by_type(struct path *path, void *p)
226{
227 struct autofs_info *ino = autofs4_dentry_ino(path->dentry);
228 return ino && ino->sbi->type & *(unsigned *)p;
229}
230
231static void autofs_dev_ioctl_fd_install(unsigned int fd, struct file *file)
232{
233 struct files_struct *files = current->files;
234 struct fdtable *fdt;
235
236 spin_lock(&files->file_lock);
237 fdt = files_fdtable(files);
238 BUG_ON(fdt->fd[fd] != NULL);
239 rcu_assign_pointer(fdt->fd[fd], file);
240 __set_close_on_exec(fd, fdt);
241 spin_unlock(&files->file_lock);
242}
243
244
245/*
246 * Open a file descriptor on the autofs mount point corresponding
247 * to the given path and device number (aka. new_encode_dev(sb->s_dev)).
248 */
249static int autofs_dev_ioctl_open_mountpoint(const char *name, dev_t devid)
250{
251 int err, fd;
252
253 fd = get_unused_fd();
254 if (likely(fd >= 0)) {
255 struct file *filp;
256 struct path path;
257
258 err = find_autofs_mount(name, &path, test_by_dev, &devid);
259 if (err)
260 goto out;
261
262 /*
263 * Find autofs super block that has the device number
264 * corresponding to the autofs fs we want to open.
265 */
266
267 filp = dentry_open(path.dentry, path.mnt, O_RDONLY,
268 current_cred());
269 if (IS_ERR(filp)) {
270 err = PTR_ERR(filp);
271 goto out;
272 }
273
274 autofs_dev_ioctl_fd_install(fd, filp);
275 }
276
277 return fd;
278
279out:
280 put_unused_fd(fd);
281 return err;
282}
283
284/* Open a file descriptor on an autofs mount point */
285static int autofs_dev_ioctl_openmount(struct file *fp,
286 struct autofs_sb_info *sbi,
287 struct autofs_dev_ioctl *param)
288{
289 const char *path;
290 dev_t devid;
291 int err, fd;
292
293 /* param->path has already been checked */
294 if (!param->openmount.devid)
295 return -EINVAL;
296
297 param->ioctlfd = -1;
298
299 path = param->path;
300 devid = new_decode_dev(param->openmount.devid);
301
302 err = 0;
303 fd = autofs_dev_ioctl_open_mountpoint(path, devid);
304 if (unlikely(fd < 0)) {
305 err = fd;
306 goto out;
307 }
308
309 param->ioctlfd = fd;
310out:
311 return err;
312}
313
314/* Close file descriptor allocated above (user can also use close(2)). */
315static int autofs_dev_ioctl_closemount(struct file *fp,
316 struct autofs_sb_info *sbi,
317 struct autofs_dev_ioctl *param)
318{
319 return sys_close(param->ioctlfd);
320}
321
322/*
323 * Send "ready" status for an existing wait (either a mount or an expire
324 * request).
325 */
326static int autofs_dev_ioctl_ready(struct file *fp,
327 struct autofs_sb_info *sbi,
328 struct autofs_dev_ioctl *param)
329{
330 autofs_wqt_t token;
331
332 token = (autofs_wqt_t) param->ready.token;
333 return autofs4_wait_release(sbi, token, 0);
334}
335
336/*
337 * Send "fail" status for an existing wait (either a mount or an expire
338 * request).
339 */
340static int autofs_dev_ioctl_fail(struct file *fp,
341 struct autofs_sb_info *sbi,
342 struct autofs_dev_ioctl *param)
343{
344 autofs_wqt_t token;
345 int status;
346
347 token = (autofs_wqt_t) param->fail.token;
348 status = param->fail.status ? param->fail.status : -ENOENT;
349 return autofs4_wait_release(sbi, token, status);
350}
351
352/*
353 * Set the pipe fd for kernel communication to the daemon.
354 *
355 * Normally this is set at mount using an option but if we
356 * are reconnecting to a busy mount then we need to use this
357 * to tell the autofs mount about the new kernel pipe fd. In
358 * order to protect mounts against incorrectly setting the
359 * pipefd we also require that the autofs mount be catatonic.
360 *
361 * This also sets the process group id used to identify the
362 * controlling process (eg. the owning automount(8) daemon).
363 */
364static int autofs_dev_ioctl_setpipefd(struct file *fp,
365 struct autofs_sb_info *sbi,
366 struct autofs_dev_ioctl *param)
367{
368 int pipefd;
369 int err = 0;
370
371 if (param->setpipefd.pipefd == -1)
372 return -EINVAL;
373
374 pipefd = param->setpipefd.pipefd;
375
376 mutex_lock(&sbi->wq_mutex);
377 if (!sbi->catatonic) {
378 mutex_unlock(&sbi->wq_mutex);
379 return -EBUSY;
380 } else {
381 struct file *pipe = fget(pipefd);
382 if (!pipe) {
383 err = -EBADF;
384 goto out;
385 }
386 if (autofs_prepare_pipe(pipe) < 0) {
387 err = -EPIPE;
388 fput(pipe);
389 goto out;
390 }
391 sbi->oz_pgrp = task_pgrp_nr(current);
392 sbi->pipefd = pipefd;
393 sbi->pipe = pipe;
394 sbi->catatonic = 0;
395 }
396out:
397 mutex_unlock(&sbi->wq_mutex);
398 return err;
399}
400
401/*
402 * Make the autofs mount point catatonic, no longer responsive to
403 * mount requests. Also closes the kernel pipe file descriptor.
404 */
405static int autofs_dev_ioctl_catatonic(struct file *fp,
406 struct autofs_sb_info *sbi,
407 struct autofs_dev_ioctl *param)
408{
409 autofs4_catatonic_mode(sbi);
410 return 0;
411}
412
413/* Set the autofs mount timeout */
414static int autofs_dev_ioctl_timeout(struct file *fp,
415 struct autofs_sb_info *sbi,
416 struct autofs_dev_ioctl *param)
417{
418 unsigned long timeout;
419
420 timeout = param->timeout.timeout;
421 param->timeout.timeout = sbi->exp_timeout / HZ;
422 sbi->exp_timeout = timeout * HZ;
423 return 0;
424}
425
426/*
427 * Return the uid and gid of the last request for the mount
428 *
429 * When reconstructing an autofs mount tree with active mounts
430 * we need to re-connect to mounts that may have used the original
431 * process uid and gid (or string variations of them) for mount
432 * lookups within the map entry.
433 */
434static int autofs_dev_ioctl_requester(struct file *fp,
435 struct autofs_sb_info *sbi,
436 struct autofs_dev_ioctl *param)
437{
438 struct autofs_info *ino;
439 struct path path;
440 dev_t devid;
441 int err = -ENOENT;
442
443 if (param->size <= sizeof(*param)) {
444 err = -EINVAL;
445 goto out;
446 }
447
448 devid = sbi->sb->s_dev;
449
450 param->requester.uid = param->requester.gid = -1;
451
452 err = find_autofs_mount(param->path, &path, test_by_dev, &devid);
453 if (err)
454 goto out;
455
456 ino = autofs4_dentry_ino(path.dentry);
457 if (ino) {
458 err = 0;
459 autofs4_expire_wait(path.dentry);
460 spin_lock(&sbi->fs_lock);
461 param->requester.uid = ino->uid;
462 param->requester.gid = ino->gid;
463 spin_unlock(&sbi->fs_lock);
464 }
465 path_put(&path);
466out:
467 return err;
468}
469
470/*
471 * Call repeatedly until it returns -EAGAIN, meaning there's nothing
472 * more that can be done.
473 */
474static int autofs_dev_ioctl_expire(struct file *fp,
475 struct autofs_sb_info *sbi,
476 struct autofs_dev_ioctl *param)
477{
478 struct vfsmount *mnt;
479 int how;
480
481 how = param->expire.how;
482 mnt = fp->f_path.mnt;
483
484 return autofs4_do_expire_multi(sbi->sb, mnt, sbi, how);
485}
486
487/* Check if autofs mount point is in use */
488static int autofs_dev_ioctl_askumount(struct file *fp,
489 struct autofs_sb_info *sbi,
490 struct autofs_dev_ioctl *param)
491{
492 param->askumount.may_umount = 0;
493 if (may_umount(fp->f_path.mnt))
494 param->askumount.may_umount = 1;
495 return 0;
496}
497
498/*
499 * Check if the given path is a mountpoint.
500 *
501 * If we are supplied with the file descriptor of an autofs
502 * mount we're looking for a specific mount. In this case
503 * the path is considered a mountpoint if it is itself a
504 * mountpoint or contains a mount, such as a multi-mount
505 * without a root mount. In this case we return 1 if the
506 * path is a mount point and the super magic of the covering
507 * mount if there is one or 0 if it isn't a mountpoint.
508 *
509 * If we aren't supplied with a file descriptor then we
510 * lookup the nameidata of the path and check if it is the
511 * root of a mount. If a type is given we are looking for
512 * a particular autofs mount and if we don't find a match
513 * we return fail. If the located nameidata path is the
514 * root of a mount we return 1 along with the super magic
515 * of the mount or 0 otherwise.
516 *
517 * In both cases the the device number (as returned by
518 * new_encode_dev()) is also returned.
519 */
520static int autofs_dev_ioctl_ismountpoint(struct file *fp,
521 struct autofs_sb_info *sbi,
522 struct autofs_dev_ioctl *param)
523{
524 struct path path;
525 const char *name;
526 unsigned int type;
527 unsigned int devid, magic;
528 int err = -ENOENT;
529
530 if (param->size <= sizeof(*param)) {
531 err = -EINVAL;
532 goto out;
533 }
534
535 name = param->path;
536 type = param->ismountpoint.in.type;
537
538 param->ismountpoint.out.devid = devid = 0;
539 param->ismountpoint.out.magic = magic = 0;
540
541 if (!fp || param->ioctlfd == -1) {
542 if (autofs_type_any(type))
543 err = kern_path(name, LOOKUP_FOLLOW, &path);
544 else
545 err = find_autofs_mount(name, &path, test_by_type, &type);
546 if (err)
547 goto out;
548 devid = new_encode_dev(path.dentry->d_sb->s_dev);
549 err = 0;
550 if (path.mnt->mnt_root == path.dentry) {
551 err = 1;
552 magic = path.dentry->d_sb->s_magic;
553 }
554 } else {
555 dev_t dev = sbi->sb->s_dev;
556
557 err = find_autofs_mount(name, &path, test_by_dev, &dev);
558 if (err)
559 goto out;
560
561 devid = new_encode_dev(dev);
562
563 err = have_submounts(path.dentry);
564
565 if (follow_down_one(&path))
566 magic = path.dentry->d_sb->s_magic;
567 }
568
569 param->ismountpoint.out.devid = devid;
570 param->ismountpoint.out.magic = magic;
571 path_put(&path);
572out:
573 return err;
574}
575
576/*
577 * Our range of ioctl numbers isn't 0 based so we need to shift
578 * the array index by _IOC_NR(AUTOFS_CTL_IOC_FIRST) for the table
579 * lookup.
580 */
581#define cmd_idx(cmd) (cmd - _IOC_NR(AUTOFS_DEV_IOCTL_IOC_FIRST))
582
583static ioctl_fn lookup_dev_ioctl(unsigned int cmd)
584{
585 static struct {
586 int cmd;
587 ioctl_fn fn;
588 } _ioctls[] = {
589 {cmd_idx(AUTOFS_DEV_IOCTL_VERSION_CMD), NULL},
590 {cmd_idx(AUTOFS_DEV_IOCTL_PROTOVER_CMD),
591 autofs_dev_ioctl_protover},
592 {cmd_idx(AUTOFS_DEV_IOCTL_PROTOSUBVER_CMD),
593 autofs_dev_ioctl_protosubver},
594 {cmd_idx(AUTOFS_DEV_IOCTL_OPENMOUNT_CMD),
595 autofs_dev_ioctl_openmount},
596 {cmd_idx(AUTOFS_DEV_IOCTL_CLOSEMOUNT_CMD),
597 autofs_dev_ioctl_closemount},
598 {cmd_idx(AUTOFS_DEV_IOCTL_READY_CMD),
599 autofs_dev_ioctl_ready},
600 {cmd_idx(AUTOFS_DEV_IOCTL_FAIL_CMD),
601 autofs_dev_ioctl_fail},
602 {cmd_idx(AUTOFS_DEV_IOCTL_SETPIPEFD_CMD),
603 autofs_dev_ioctl_setpipefd},
604 {cmd_idx(AUTOFS_DEV_IOCTL_CATATONIC_CMD),
605 autofs_dev_ioctl_catatonic},
606 {cmd_idx(AUTOFS_DEV_IOCTL_TIMEOUT_CMD),
607 autofs_dev_ioctl_timeout},
608 {cmd_idx(AUTOFS_DEV_IOCTL_REQUESTER_CMD),
609 autofs_dev_ioctl_requester},
610 {cmd_idx(AUTOFS_DEV_IOCTL_EXPIRE_CMD),
611 autofs_dev_ioctl_expire},
612 {cmd_idx(AUTOFS_DEV_IOCTL_ASKUMOUNT_CMD),
613 autofs_dev_ioctl_askumount},
614 {cmd_idx(AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD),
615 autofs_dev_ioctl_ismountpoint}
616 };
617 unsigned int idx = cmd_idx(cmd);
618
619 return (idx >= ARRAY_SIZE(_ioctls)) ? NULL : _ioctls[idx].fn;
620}
621
622/* ioctl dispatcher */
623static int _autofs_dev_ioctl(unsigned int command, struct autofs_dev_ioctl __user *user)
624{
625 struct autofs_dev_ioctl *param;
626 struct file *fp;
627 struct autofs_sb_info *sbi;
628 unsigned int cmd_first, cmd;
629 ioctl_fn fn = NULL;
630 int err = 0;
631
632 /* only root can play with this */
633 if (!capable(CAP_SYS_ADMIN))
634 return -EPERM;
635
636 cmd_first = _IOC_NR(AUTOFS_DEV_IOCTL_IOC_FIRST);
637 cmd = _IOC_NR(command);
638
639 if (_IOC_TYPE(command) != _IOC_TYPE(AUTOFS_DEV_IOCTL_IOC_FIRST) ||
640 cmd - cmd_first >= AUTOFS_DEV_IOCTL_IOC_COUNT) {
641 return -ENOTTY;
642 }
643
644 /* Copy the parameters into kernel space. */
645 param = copy_dev_ioctl(user);
646 if (IS_ERR(param))
647 return PTR_ERR(param);
648
649 err = validate_dev_ioctl(command, param);
650 if (err)
651 goto out;
652
653 /* The validate routine above always sets the version */
654 if (cmd == AUTOFS_DEV_IOCTL_VERSION_CMD)
655 goto done;
656
657 fn = lookup_dev_ioctl(cmd);
658 if (!fn) {
659 AUTOFS_WARN("unknown command 0x%08x", command);
660 return -ENOTTY;
661 }
662
663 fp = NULL;
664 sbi = NULL;
665
666 /*
667 * For obvious reasons the openmount can't have a file
668 * descriptor yet. We don't take a reference to the
669 * file during close to allow for immediate release.
670 */
671 if (cmd != AUTOFS_DEV_IOCTL_OPENMOUNT_CMD &&
672 cmd != AUTOFS_DEV_IOCTL_CLOSEMOUNT_CMD) {
673 fp = fget(param->ioctlfd);
674 if (!fp) {
675 if (cmd == AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD)
676 goto cont;
677 err = -EBADF;
678 goto out;
679 }
680
681 if (!fp->f_op) {
682 err = -ENOTTY;
683 fput(fp);
684 goto out;
685 }
686
687 sbi = autofs_dev_ioctl_sbi(fp);
688 if (!sbi || sbi->magic != AUTOFS_SBI_MAGIC) {
689 err = -EINVAL;
690 fput(fp);
691 goto out;
692 }
693
694 /*
695 * Admin needs to be able to set the mount catatonic in
696 * order to be able to perform the re-open.
697 */
698 if (!autofs4_oz_mode(sbi) &&
699 cmd != AUTOFS_DEV_IOCTL_CATATONIC_CMD) {
700 err = -EACCES;
701 fput(fp);
702 goto out;
703 }
704 }
705cont:
706 err = fn(fp, sbi, param);
707
708 if (fp)
709 fput(fp);
710done:
711 if (err >= 0 && copy_to_user(user, param, AUTOFS_DEV_IOCTL_SIZE))
712 err = -EFAULT;
713out:
714 free_dev_ioctl(param);
715 return err;
716}
717
718static long autofs_dev_ioctl(struct file *file, uint command, ulong u)
719{
720 int err;
721 err = _autofs_dev_ioctl(command, (struct autofs_dev_ioctl __user *) u);
722 return (long) err;
723}
724
725#ifdef CONFIG_COMPAT
726static long autofs_dev_ioctl_compat(struct file *file, uint command, ulong u)
727{
728 return (long) autofs_dev_ioctl(file, command, (ulong) compat_ptr(u));
729}
730#else
731#define autofs_dev_ioctl_compat NULL
732#endif
733
734static const struct file_operations _dev_ioctl_fops = {
735 .unlocked_ioctl = autofs_dev_ioctl,
736 .compat_ioctl = autofs_dev_ioctl_compat,
737 .owner = THIS_MODULE,
738 .llseek = noop_llseek,
739};
740
741static struct miscdevice _autofs_dev_ioctl_misc = {
742 .minor = AUTOFS_MINOR,
743 .name = AUTOFS_DEVICE_NAME,
744 .fops = &_dev_ioctl_fops
745};
746
747MODULE_ALIAS_MISCDEV(AUTOFS_MINOR);
748MODULE_ALIAS("devname:autofs");
749
750/* Register/deregister misc character device */
751int autofs_dev_ioctl_init(void)
752{
753 int r;
754
755 r = misc_register(&_autofs_dev_ioctl_misc);
756 if (r) {
757 AUTOFS_ERROR("misc_register failed for control device");
758 return r;
759 }
760
761 return 0;
762}
763
764void autofs_dev_ioctl_exit(void)
765{
766 misc_deregister(&_autofs_dev_ioctl_misc);
767 return;
768}
769