blob: dbb5b7212ce162130727256d49351e3f2d2677c9 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/* -*- c -*- --------------------------------------------------------------- *
2 *
3 * linux/fs/autofs/root.c
4 *
5 * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
6 * Copyright 1999-2000 Jeremy Fitzhardinge <jeremy@goop.org>
Ian Kent34ca9592006-03-27 01:14:54 -08007 * Copyright 2001-2006 Ian Kent <raven@themaw.net>
Linus Torvalds1da177e2005-04-16 15:20:36 -07008 *
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.
12 *
13 * ------------------------------------------------------------------------- */
14
Randy Dunlap16f7e0f2006-01-11 12:17:46 -080015#include <linux/capability.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070016#include <linux/errno.h>
17#include <linux/stat.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090018#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070019#include <linux/param.h>
20#include <linux/time.h>
Arnd Bergmannc9243f52010-07-04 00:15:07 +020021#include <linux/compat.h>
Arnd Bergmann00e300e2010-09-14 23:00:34 +020022#include <linux/mutex.h>
Arnd Bergmannc9243f52010-07-04 00:15:07 +020023
Linus Torvalds1da177e2005-04-16 15:20:36 -070024#include "autofs_i.h"
25
26static int autofs4_dir_symlink(struct inode *,struct dentry *,const char *);
27static int autofs4_dir_unlink(struct inode *,struct dentry *);
28static int autofs4_dir_rmdir(struct inode *,struct dentry *);
Al Viro18bb1db2011-07-26 01:41:39 -040029static int autofs4_dir_mkdir(struct inode *,struct dentry *,umode_t);
Frederic Weisbecker3663df72010-05-19 15:08:17 +020030static long autofs4_root_ioctl(struct file *,unsigned int,unsigned long);
Felipe Contreras5a44a732010-09-24 15:22:23 +020031#ifdef CONFIG_COMPAT
Arnd Bergmannc9243f52010-07-04 00:15:07 +020032static long autofs4_root_compat_ioctl(struct file *,unsigned int,unsigned long);
Felipe Contreras5a44a732010-09-24 15:22:23 +020033#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070034static int autofs4_dir_open(struct inode *inode, struct file *file);
Al Viro00cd8dd2012-06-10 17:13:09 -040035static struct dentry *autofs4_lookup(struct inode *,struct dentry *, unsigned int);
Ian Kent71e469d2011-01-14 18:46:19 +000036static struct vfsmount *autofs4_d_automount(struct path *);
Al Viro1aed3e42011-03-18 09:09:02 -040037static int autofs4_d_manage(struct dentry *, bool);
Al Virob89b12b2011-01-16 21:42:32 -050038static void autofs4_dentry_release(struct dentry *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070039
Arjan van de Ven4b6f5d22006-03-28 01:56:42 -080040const struct file_operations autofs4_root_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -070041 .open = dcache_dir_open,
42 .release = dcache_dir_close,
43 .read = generic_read_dir,
Al Viro5f99f4e2013-05-15 20:23:06 -040044 .iterate = dcache_readdir,
Al Viro59af1582008-08-24 07:24:41 -040045 .llseek = dcache_dir_lseek,
Frederic Weisbecker3663df72010-05-19 15:08:17 +020046 .unlocked_ioctl = autofs4_root_ioctl,
Arnd Bergmannc9243f52010-07-04 00:15:07 +020047#ifdef CONFIG_COMPAT
48 .compat_ioctl = autofs4_root_compat_ioctl,
49#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070050};
51
Arjan van de Ven4b6f5d22006-03-28 01:56:42 -080052const struct file_operations autofs4_dir_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -070053 .open = autofs4_dir_open,
Ian Kentff9cd492008-07-23 21:30:24 -070054 .release = dcache_dir_close,
Linus Torvalds1da177e2005-04-16 15:20:36 -070055 .read = generic_read_dir,
Al Viro5f99f4e2013-05-15 20:23:06 -040056 .iterate = dcache_readdir,
Al Viro59af1582008-08-24 07:24:41 -040057 .llseek = dcache_dir_lseek,
Linus Torvalds1da177e2005-04-16 15:20:36 -070058};
59
Arjan van de Ven754661f2007-02-12 00:55:38 -080060const struct inode_operations autofs4_dir_inode_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -070061 .lookup = autofs4_lookup,
62 .unlink = autofs4_dir_unlink,
63 .symlink = autofs4_dir_symlink,
64 .mkdir = autofs4_dir_mkdir,
65 .rmdir = autofs4_dir_rmdir,
66};
67
Ian Kent71e469d2011-01-14 18:46:19 +000068const struct dentry_operations autofs4_dentry_operations = {
Ian Kent71e469d2011-01-14 18:46:19 +000069 .d_automount = autofs4_d_automount,
70 .d_manage = autofs4_d_manage,
71 .d_release = autofs4_dentry_release,
72};
73
Ian Kent4f8427d2009-12-15 16:45:42 -080074static void autofs4_add_active(struct dentry *dentry)
75{
76 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
77 struct autofs_info *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);
83 }
84 ino->active_count++;
85 spin_unlock(&sbi->lookup_lock);
86 }
87 return;
88}
89
90static void autofs4_del_active(struct dentry *dentry)
91{
92 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
93 struct autofs_info *ino = autofs4_dentry_ino(dentry);
94 if (ino) {
95 spin_lock(&sbi->lookup_lock);
96 ino->active_count--;
97 if (!ino->active_count) {
98 if (!list_empty(&ino->active))
99 list_del_init(&ino->active);
100 }
101 spin_unlock(&sbi->lookup_lock);
102 }
103 return;
104}
105
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106static int autofs4_dir_open(struct inode *inode, struct file *file)
107{
Josef "Jeff" Sipeka4669ed2006-12-08 02:36:46 -0800108 struct dentry *dentry = file->f_path.dentry;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
Ian Kentf360ce32006-03-27 01:14:43 -0800110
Al Viroa4555892014-10-21 20:11:25 -0400111 DPRINTK("file=%p dentry=%p %pD", file, dentry, dentry);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112
113 if (autofs4_oz_mode(sbi))
114 goto out;
115
Ian Kentff9cd492008-07-23 21:30:24 -0700116 /*
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.
124 */
Ian Kente7854722011-03-25 01:51:31 +0800125 spin_lock(&sbi->lookup_lock);
Ian Kent0259cb02012-12-14 10:23:29 +0800126 if (!d_mountpoint(dentry) && simple_empty(dentry)) {
Ian Kente7854722011-03-25 01:51:31 +0800127 spin_unlock(&sbi->lookup_lock);
Ian Kentff9cd492008-07-23 21:30:24 -0700128 return -ENOENT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129 }
Ian Kente7854722011-03-25 01:51:31 +0800130 spin_unlock(&sbi->lookup_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131
Ian Kentf360ce32006-03-27 01:14:43 -0800132out:
Ian Kentff9cd492008-07-23 21:30:24 -0700133 return dcache_dir_open(inode, file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134}
135
Al Virob89b12b2011-01-16 21:42:32 -0500136static void autofs4_dentry_release(struct dentry *de)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137{
Al Virob89b12b2011-01-16 21:42:32 -0500138 struct autofs_info *ino = autofs4_dentry_ino(de);
139 struct autofs_sb_info *sbi = autofs4_sbi(de->d_sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140
141 DPRINTK("releasing %p", de);
142
Al Virob89b12b2011-01-16 21:42:32 -0500143 if (!ino)
144 return;
145
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);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153 }
Al Virob89b12b2011-01-16 21:42:32 -0500154
155 autofs4_free_ino(ino);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700156}
157
Ian Kent6510c9d2009-12-15 16:45:47 -0800158static struct dentry *autofs4_lookup_active(struct dentry *dentry)
Ian Kent25767372008-07-23 21:30:12 -0700159{
Ian Kent6510c9d2009-12-15 16:45:47 -0800160 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
161 struct dentry *parent = dentry->d_parent;
162 struct qstr *name = &dentry->d_name;
Ian Kent25767372008-07-23 21:30:12 -0700163 unsigned int len = name->len;
164 unsigned int hash = name->hash;
165 const unsigned char *str = name->name;
166 struct list_head *p, *head;
167
Ian Kent25767372008-07-23 21:30:12 -0700168 head = &sbi->active_list;
NeilBrown668128e2014-08-08 14:19:54 -0700169 if (list_empty(head))
170 return NULL;
171 spin_lock(&sbi->lookup_lock);
Ian Kent25767372008-07-23 21:30:12 -0700172 list_for_each(p, head) {
173 struct autofs_info *ino;
Ian Kente4d5ade2009-12-15 16:45:49 -0800174 struct dentry *active;
Ian Kent25767372008-07-23 21:30:12 -0700175 struct qstr *qstr;
176
177 ino = list_entry(p, struct autofs_info, active);
Ian Kente4d5ade2009-12-15 16:45:49 -0800178 active = ino->dentry;
Ian Kent25767372008-07-23 21:30:12 -0700179
Ian Kente4d5ade2009-12-15 16:45:49 -0800180 spin_lock(&active->d_lock);
Ian Kent25767372008-07-23 21:30:12 -0700181
182 /* Already gone? */
Ian Kent6b6751f2014-05-06 12:50:06 -0700183 if ((int) d_count(active) <= 0)
Ian Kent25767372008-07-23 21:30:12 -0700184 goto next;
185
Ian Kente4d5ade2009-12-15 16:45:49 -0800186 qstr = &active->d_name;
Ian Kent25767372008-07-23 21:30:12 -0700187
Ian Kente4d5ade2009-12-15 16:45:49 -0800188 if (active->d_name.hash != hash)
Ian Kent25767372008-07-23 21:30:12 -0700189 goto next;
Ian Kente4d5ade2009-12-15 16:45:49 -0800190 if (active->d_parent != parent)
Ian Kent25767372008-07-23 21:30:12 -0700191 goto next;
192
193 if (qstr->len != len)
194 goto next;
195 if (memcmp(qstr->name, str, len))
196 goto next;
197
Al Viro4b1ae272010-03-03 12:58:31 -0500198 if (d_unhashed(active)) {
Nick Pigginb7ab39f2011-01-07 17:49:32 +1100199 dget_dlock(active);
Al Viro4b1ae272010-03-03 12:58:31 -0500200 spin_unlock(&active->d_lock);
201 spin_unlock(&sbi->lookup_lock);
Al Viro4b1ae272010-03-03 12:58:31 -0500202 return active;
203 }
Ian Kent25767372008-07-23 21:30:12 -0700204next:
Ian Kente4d5ade2009-12-15 16:45:49 -0800205 spin_unlock(&active->d_lock);
Ian Kent25767372008-07-23 21:30:12 -0700206 }
207 spin_unlock(&sbi->lookup_lock);
Ian Kent25767372008-07-23 21:30:12 -0700208
209 return NULL;
210}
211
NeilBrown23bfc2a2014-10-13 15:52:14 -0700212static struct dentry *autofs4_lookup_expiring(struct dentry *dentry,
213 bool rcu_walk)
Ian Kentf50b6f82007-02-20 13:58:10 -0800214{
Ian Kent6510c9d2009-12-15 16:45:47 -0800215 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
216 struct dentry *parent = dentry->d_parent;
217 struct qstr *name = &dentry->d_name;
Ian Kentf50b6f82007-02-20 13:58:10 -0800218 unsigned int len = name->len;
219 unsigned int hash = name->hash;
220 const unsigned char *str = name->name;
221 struct list_head *p, *head;
222
Ian Kent5f6f4f22008-07-23 21:30:09 -0700223 head = &sbi->expiring_list;
NeilBrown668128e2014-08-08 14:19:54 -0700224 if (list_empty(head))
225 return NULL;
226 spin_lock(&sbi->lookup_lock);
Ian Kentf50b6f82007-02-20 13:58:10 -0800227 list_for_each(p, head) {
228 struct autofs_info *ino;
Ian Kentcb4b4922009-12-15 16:45:50 -0800229 struct dentry *expiring;
Ian Kentf50b6f82007-02-20 13:58:10 -0800230 struct qstr *qstr;
231
NeilBrown23bfc2a2014-10-13 15:52:14 -0700232 if (rcu_walk) {
233 spin_unlock(&sbi->lookup_lock);
234 return ERR_PTR(-ECHILD);
235 }
236
Ian Kent5f6f4f22008-07-23 21:30:09 -0700237 ino = list_entry(p, struct autofs_info, expiring);
Ian Kentcb4b4922009-12-15 16:45:50 -0800238 expiring = ino->dentry;
Ian Kentf50b6f82007-02-20 13:58:10 -0800239
Ian Kentcb4b4922009-12-15 16:45:50 -0800240 spin_lock(&expiring->d_lock);
Ian Kentf50b6f82007-02-20 13:58:10 -0800241
Ian Kent6b6751f2014-05-06 12:50:06 -0700242 /* We've already been dentry_iput or unlinked */
Ian Kentcb4b4922009-12-15 16:45:50 -0800243 if (!expiring->d_inode)
Ian Kentf50b6f82007-02-20 13:58:10 -0800244 goto next;
245
Ian Kentcb4b4922009-12-15 16:45:50 -0800246 qstr = &expiring->d_name;
Ian Kentf50b6f82007-02-20 13:58:10 -0800247
Ian Kentcb4b4922009-12-15 16:45:50 -0800248 if (expiring->d_name.hash != hash)
Ian Kentf50b6f82007-02-20 13:58:10 -0800249 goto next;
Ian Kentcb4b4922009-12-15 16:45:50 -0800250 if (expiring->d_parent != parent)
Ian Kentf50b6f82007-02-20 13:58:10 -0800251 goto next;
252
253 if (qstr->len != len)
254 goto next;
255 if (memcmp(qstr->name, str, len))
256 goto next;
257
Al Viro4b1ae272010-03-03 12:58:31 -0500258 if (d_unhashed(expiring)) {
Nick Pigginb7ab39f2011-01-07 17:49:32 +1100259 dget_dlock(expiring);
Al Viro4b1ae272010-03-03 12:58:31 -0500260 spin_unlock(&expiring->d_lock);
261 spin_unlock(&sbi->lookup_lock);
Al Viro4b1ae272010-03-03 12:58:31 -0500262 return expiring;
263 }
Ian Kentf50b6f82007-02-20 13:58:10 -0800264next:
Ian Kentcb4b4922009-12-15 16:45:50 -0800265 spin_unlock(&expiring->d_lock);
Ian Kentf50b6f82007-02-20 13:58:10 -0800266 }
Ian Kent5f6f4f22008-07-23 21:30:09 -0700267 spin_unlock(&sbi->lookup_lock);
Ian Kentf50b6f82007-02-20 13:58:10 -0800268
269 return NULL;
270}
271
NeilBrown23bfc2a2014-10-13 15:52:14 -0700272static int autofs4_mount_wait(struct dentry *dentry, bool rcu_walk)
Ian Kent10584212011-01-14 18:45:58 +0000273{
274 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
275 struct autofs_info *ino = autofs4_dentry_ino(dentry);
Ian Kent3c319982011-03-25 01:51:08 +0800276 int status = 0;
Ian Kent10584212011-01-14 18:45:58 +0000277
278 if (ino->flags & AUTOFS_INF_PENDING) {
NeilBrown23bfc2a2014-10-13 15:52:14 -0700279 if (rcu_walk)
280 return -ECHILD;
Al Viroa4555892014-10-21 20:11:25 -0400281 DPRINTK("waiting for mount name=%pd", dentry);
Ian Kent10584212011-01-14 18:45:58 +0000282 status = autofs4_wait(sbi, dentry, NFY_MOUNT);
283 DPRINTK("mount wait done status=%d", status);
Ian Kent10584212011-01-14 18:45:58 +0000284 }
Ian Kent3c319982011-03-25 01:51:08 +0800285 ino->last_used = jiffies;
286 return status;
Ian Kent10584212011-01-14 18:45:58 +0000287}
288
NeilBrown23bfc2a2014-10-13 15:52:14 -0700289static int do_expire_wait(struct dentry *dentry, bool rcu_walk)
Ian Kent10584212011-01-14 18:45:58 +0000290{
291 struct dentry *expiring;
292
NeilBrown23bfc2a2014-10-13 15:52:14 -0700293 expiring = autofs4_lookup_expiring(dentry, rcu_walk);
294 if (IS_ERR(expiring))
295 return PTR_ERR(expiring);
Ian Kent10584212011-01-14 18:45:58 +0000296 if (!expiring)
NeilBrown23bfc2a2014-10-13 15:52:14 -0700297 return autofs4_expire_wait(dentry, rcu_walk);
Ian Kent10584212011-01-14 18:45:58 +0000298 else {
299 /*
300 * If we are racing with expire the request might not
301 * be quite complete, but the directory has been removed
302 * so it must have been successful, just wait for it.
303 */
NeilBrown23bfc2a2014-10-13 15:52:14 -0700304 autofs4_expire_wait(expiring, 0);
Ian Kent10584212011-01-14 18:45:58 +0000305 autofs4_del_expiring(expiring);
306 dput(expiring);
307 }
308 return 0;
309}
310
311static struct dentry *autofs4_mountpoint_changed(struct path *path)
312{
313 struct dentry *dentry = path->dentry;
314 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
315
316 /*
317 * If this is an indirect mount the dentry could have gone away
318 * as a result of an expire and a new one created.
319 */
320 if (autofs_type_indirect(sbi->type) && d_unhashed(dentry)) {
321 struct dentry *parent = dentry->d_parent;
Ian Kent3c319982011-03-25 01:51:08 +0800322 struct autofs_info *ino;
Ian Kent10584212011-01-14 18:45:58 +0000323 struct dentry *new = d_lookup(parent, &dentry->d_name);
324 if (!new)
325 return NULL;
Ian Kent3c319982011-03-25 01:51:08 +0800326 ino = autofs4_dentry_ino(new);
327 ino->last_used = jiffies;
Ian Kent10584212011-01-14 18:45:58 +0000328 dput(path->dentry);
329 path->dentry = new;
330 }
331 return path->dentry;
332}
333
Ian Kent71e469d2011-01-14 18:46:19 +0000334static struct vfsmount *autofs4_d_automount(struct path *path)
Ian Kent10584212011-01-14 18:45:58 +0000335{
336 struct dentry *dentry = path->dentry;
337 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
338 struct autofs_info *ino = autofs4_dentry_ino(dentry);
339 int status;
340
Al Viroa4555892014-10-21 20:11:25 -0400341 DPRINTK("dentry=%p %pd", dentry, dentry);
Ian Kent10584212011-01-14 18:45:58 +0000342
343 /* The daemon never triggers a mount. */
344 if (autofs4_oz_mode(sbi))
345 return NULL;
346
347 /*
348 * If an expire request is pending everyone must wait.
349 * If the expire fails we're still mounted so continue
350 * the follow and return. A return of -EAGAIN (which only
351 * happens with indirect mounts) means the expire completed
352 * and the directory was removed, so just go ahead and try
353 * the mount.
354 */
NeilBrown23bfc2a2014-10-13 15:52:14 -0700355 status = do_expire_wait(dentry, 0);
Ian Kent10584212011-01-14 18:45:58 +0000356 if (status && status != -EAGAIN)
357 return NULL;
358
359 /* Callback to the daemon to perform the mount or wait */
360 spin_lock(&sbi->fs_lock);
361 if (ino->flags & AUTOFS_INF_PENDING) {
362 spin_unlock(&sbi->fs_lock);
NeilBrown23bfc2a2014-10-13 15:52:14 -0700363 status = autofs4_mount_wait(dentry, 0);
Ian Kent10584212011-01-14 18:45:58 +0000364 if (status)
365 return ERR_PTR(status);
Ian Kent10584212011-01-14 18:45:58 +0000366 goto done;
367 }
368
369 /*
370 * If the dentry is a symlink it's equivalent to a directory
Ian Kentb5b80172011-01-14 18:46:03 +0000371 * having d_mountpoint() true, so there's no need to call back
Ian Kent10584212011-01-14 18:45:58 +0000372 * to the daemon.
373 */
Ian Kentf55fb0c2012-12-14 10:23:23 +0800374 if (dentry->d_inode && S_ISLNK(dentry->d_inode->i_mode)) {
375 spin_unlock(&sbi->fs_lock);
Ian Kent10584212011-01-14 18:45:58 +0000376 goto done;
Ian Kentf55fb0c2012-12-14 10:23:23 +0800377 }
378
Ian Kentb5b80172011-01-14 18:46:03 +0000379 if (!d_mountpoint(dentry)) {
380 /*
381 * It's possible that user space hasn't removed directories
382 * after umounting a rootless multi-mount, although it
383 * should. For v5 have_submounts() is sufficient to handle
384 * this because the leaves of the directory tree under the
385 * mount never trigger mounts themselves (they have an autofs
386 * trigger mount mounted on them). But v4 pseudo direct mounts
NeilBrown3b97dd02014-08-08 14:19:58 -0700387 * do need the leaves to trigger mounts. In this case we
Ian Kentb5b80172011-01-14 18:46:03 +0000388 * have no choice but to use the list_empty() check and
389 * require user space behave.
390 */
391 if (sbi->version > 4) {
Ian Kentf55fb0c2012-12-14 10:23:23 +0800392 if (have_submounts(dentry)) {
393 spin_unlock(&sbi->fs_lock);
Ian Kentb5b80172011-01-14 18:46:03 +0000394 goto done;
Ian Kentf55fb0c2012-12-14 10:23:23 +0800395 }
Ian Kentb5b80172011-01-14 18:46:03 +0000396 } else {
Peter Huewe9d8072e2013-03-01 19:46:40 +0800397 if (!simple_empty(dentry)) {
398 spin_unlock(&sbi->fs_lock);
Ian Kentb5b80172011-01-14 18:46:03 +0000399 goto done;
Peter Huewe9d8072e2013-03-01 19:46:40 +0800400 }
Ian Kentb5b80172011-01-14 18:46:03 +0000401 }
Ian Kent10584212011-01-14 18:45:58 +0000402 ino->flags |= AUTOFS_INF_PENDING;
Ian Kent10584212011-01-14 18:45:58 +0000403 spin_unlock(&sbi->fs_lock);
NeilBrown23bfc2a2014-10-13 15:52:14 -0700404 status = autofs4_mount_wait(dentry, 0);
Ian Kent10584212011-01-14 18:45:58 +0000405 spin_lock(&sbi->fs_lock);
406 ino->flags &= ~AUTOFS_INF_PENDING;
Ian Kent49999ab2012-10-11 08:00:33 +0800407 if (status) {
408 spin_unlock(&sbi->fs_lock);
409 return ERR_PTR(status);
410 }
Ian Kent10584212011-01-14 18:45:58 +0000411 }
Ian Kent10584212011-01-14 18:45:58 +0000412 spin_unlock(&sbi->fs_lock);
Ian Kentf55fb0c2012-12-14 10:23:23 +0800413done:
Ian Kent10584212011-01-14 18:45:58 +0000414 /* Mount succeeded, check if we ended up with a new dentry */
415 dentry = autofs4_mountpoint_changed(path);
416 if (!dentry)
417 return ERR_PTR(-ENOENT);
418
419 return NULL;
420}
421
Claudiu Ghioc95482982013-05-06 13:47:16 +0800422static int autofs4_d_manage(struct dentry *dentry, bool rcu_walk)
Ian Kentb5b80172011-01-14 18:46:03 +0000423{
424 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
Ian Kentf55fb0c2012-12-14 10:23:23 +0800425 struct autofs_info *ino = autofs4_dentry_ino(dentry);
426 int status;
Ian Kentb5b80172011-01-14 18:46:03 +0000427
Al Viroa4555892014-10-21 20:11:25 -0400428 DPRINTK("dentry=%p %pd", dentry, dentry);
Ian Kentb5b80172011-01-14 18:46:03 +0000429
430 /* The daemon never waits. */
Al Viro1aed3e42011-03-18 09:09:02 -0400431 if (autofs4_oz_mode(sbi)) {
Ian Kentb5b80172011-01-14 18:46:03 +0000432 if (!d_mountpoint(dentry))
433 return -EISDIR;
434 return 0;
435 }
436
437 /* Wait for pending expires */
NeilBrown23bfc2a2014-10-13 15:52:14 -0700438 if (do_expire_wait(dentry, rcu_walk) == -ECHILD)
439 return -ECHILD;
Ian Kentb5b80172011-01-14 18:46:03 +0000440
441 /*
442 * This dentry may be under construction so wait on mount
443 * completion.
444 */
NeilBrown23bfc2a2014-10-13 15:52:14 -0700445 status = autofs4_mount_wait(dentry, rcu_walk);
Ian Kentf55fb0c2012-12-14 10:23:23 +0800446 if (status)
447 return status;
448
NeilBrownef16cc52014-10-13 15:52:22 -0700449 if (rcu_walk) {
450 /* We don't need fs_lock in rcu_walk mode,
451 * just testing 'AUTOFS_INFO_NO_RCU' is enough.
452 * simple_empty() takes a spinlock, so leave it
453 * to last.
454 * We only return -EISDIR when certain this isn't
455 * a mount-trap.
NeilBrown23bfc2a2014-10-13 15:52:14 -0700456 */
NeilBrownef16cc52014-10-13 15:52:22 -0700457 struct inode *inode;
458 if (ino->flags & (AUTOFS_INF_EXPIRING | AUTOFS_INF_NO_RCU))
459 return 0;
460 if (d_mountpoint(dentry))
461 return 0;
462 inode = ACCESS_ONCE(dentry->d_inode);
463 if (inode && S_ISLNK(inode->i_mode))
464 return -EISDIR;
465 if (list_empty(&dentry->d_subdirs))
466 return 0;
467 if (!simple_empty(dentry))
468 return -EISDIR;
NeilBrown23bfc2a2014-10-13 15:52:14 -0700469 return 0;
NeilBrownef16cc52014-10-13 15:52:22 -0700470 }
NeilBrown23bfc2a2014-10-13 15:52:14 -0700471
Ian Kentf55fb0c2012-12-14 10:23:23 +0800472 spin_lock(&sbi->fs_lock);
473 /*
474 * If the dentry has been selected for expire while we slept
475 * on the lock then it might go away. We'll deal with that in
476 * ->d_automount() and wait on a new mount if the expire
477 * succeeds or return here if it doesn't (since there's no
478 * mount to follow with a rootless multi-mount).
479 */
480 if (!(ino->flags & AUTOFS_INF_EXPIRING)) {
481 /*
482 * Any needed mounting has been completed and the path
483 * updated so check if this is a rootless multi-mount so
484 * we can avoid needless calls ->d_automount() and avoid
485 * an incorrect ELOOP error return.
486 */
487 if ((!d_mountpoint(dentry) && !simple_empty(dentry)) ||
488 (dentry->d_inode && S_ISLNK(dentry->d_inode->i_mode)))
489 status = -EISDIR;
490 }
491 spin_unlock(&sbi->fs_lock);
492
493 return status;
Ian Kentb5b80172011-01-14 18:46:03 +0000494}
495
Linus Torvalds1da177e2005-04-16 15:20:36 -0700496/* Lookups in the root directory */
Al Viro00cd8dd2012-06-10 17:13:09 -0400497static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700498{
499 struct autofs_sb_info *sbi;
Ian Kent25767372008-07-23 21:30:12 -0700500 struct autofs_info *ino;
Ian Kent10584212011-01-14 18:45:58 +0000501 struct dentry *active;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700502
Al Viroa4555892014-10-21 20:11:25 -0400503 DPRINTK("name = %pd", dentry);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504
Ian Kent718c6042006-03-27 01:14:42 -0800505 /* File name too long to exist */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700506 if (dentry->d_name.len > NAME_MAX)
Ian Kent718c6042006-03-27 01:14:42 -0800507 return ERR_PTR(-ENAMETOOLONG);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700508
509 sbi = autofs4_sbi(dir->i_sb);
Ian Kent718c6042006-03-27 01:14:42 -0800510
Linus Torvalds1da177e2005-04-16 15:20:36 -0700511 DPRINTK("pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d",
Ian Kentc0bcc9d2011-01-18 12:06:15 +0800512 current->pid, task_pgrp_nr(current), sbi->catatonic,
513 autofs4_oz_mode(sbi));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700514
Ian Kent6510c9d2009-12-15 16:45:47 -0800515 active = autofs4_lookup_active(dentry);
Ian Kent90387c92009-12-15 16:45:46 -0800516 if (active) {
Ian Kent10584212011-01-14 18:45:58 +0000517 return active;
Ian Kentaa952eb2009-12-15 16:45:45 -0800518 } else {
Al Viro4b1ae272010-03-03 12:58:31 -0500519 /*
Ian Kent10584212011-01-14 18:45:58 +0000520 * A dentry that is not within the root can never trigger a
521 * mount operation, unless the directory already exists, so we
522 * can return fail immediately. The daemon however does need
523 * to create directories within the file system.
Al Viro4b1ae272010-03-03 12:58:31 -0500524 */
Ian Kent10584212011-01-14 18:45:58 +0000525 if (!autofs4_oz_mode(sbi) && !IS_ROOT(dentry->d_parent))
526 return ERR_PTR(-ENOENT);
527
528 /* Mark entries in the root as mount triggers */
David Howellsb650c852011-01-15 10:51:57 +0000529 if (autofs_type_indirect(sbi->type) && IS_ROOT(dentry->d_parent))
Ian Kentb5b80172011-01-14 18:46:03 +0000530 __managed_dentry_set_managed(dentry);
Ian Kent10584212011-01-14 18:45:58 +0000531
Al Viro26e6c912011-01-16 18:43:40 -0500532 ino = autofs4_new_ino(sbi);
Al Viro4b1ae272010-03-03 12:58:31 -0500533 if (!ino)
534 return ERR_PTR(-ENOMEM);
535
536 dentry->d_fsdata = ino;
537 ino->dentry = dentry;
538
539 autofs4_add_active(dentry);
540
541 d_instantiate(dentry, NULL);
Ian Kent25767372008-07-23 21:30:12 -0700542 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700543 return NULL;
544}
545
546static int autofs4_dir_symlink(struct inode *dir,
547 struct dentry *dentry,
548 const char *symname)
549{
550 struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
551 struct autofs_info *ino = autofs4_dentry_ino(dentry);
Ian Kent1aff3c82006-03-27 01:14:46 -0800552 struct autofs_info *p_ino;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700553 struct inode *inode;
Al Viro0bf71d42011-01-16 17:39:15 -0500554 size_t size = strlen(symname);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700555 char *cp;
556
Al Viroa4555892014-10-21 20:11:25 -0400557 DPRINTK("%s <- %pd", symname, dentry);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700558
559 if (!autofs4_oz_mode(sbi))
560 return -EACCES;
561
Al Viro5a37db32011-01-16 18:29:35 -0500562 BUG_ON(!ino);
563
Al Viro26e6c912011-01-16 18:43:40 -0500564 autofs4_clean_ino(ino);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700565
Al Viro4b1ae272010-03-03 12:58:31 -0500566 autofs4_del_active(dentry);
567
Al Viro0bf71d42011-01-16 17:39:15 -0500568 cp = kmalloc(size + 1, GFP_KERNEL);
Al Viro5a37db32011-01-16 18:29:35 -0500569 if (!cp)
Ian Kent25767372008-07-23 21:30:12 -0700570 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700571
572 strcpy(cp, symname);
573
Al Viro726a5e02011-01-16 17:43:52 -0500574 inode = autofs4_get_inode(dir->i_sb, S_IFLNK | 0555);
Ian Kent25767372008-07-23 21:30:12 -0700575 if (!inode) {
576 kfree(cp);
577 if (!dentry->d_fsdata)
578 kfree(ino);
579 return -ENOMEM;
580 }
Al Viro292c5ee2011-01-17 00:47:38 -0500581 inode->i_private = cp;
Al Viro0bf71d42011-01-16 17:39:15 -0500582 inode->i_size = size;
Ian Kent1864f7b2007-08-22 14:01:54 -0700583 d_add(dentry, inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700584
Al Viro5a37db32011-01-16 18:29:35 -0500585 dget(dentry);
Ian Kent1aff3c82006-03-27 01:14:46 -0800586 atomic_inc(&ino->count);
587 p_ino = autofs4_dentry_ino(dentry->d_parent);
Rui Xiangc24930a2014-01-23 15:55:00 -0800588 if (p_ino && !IS_ROOT(dentry))
Ian Kent1aff3c82006-03-27 01:14:46 -0800589 atomic_inc(&p_ino->count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700590
591 dir->i_mtime = CURRENT_TIME;
592
593 return 0;
594}
595
596/*
597 * NOTE!
598 *
599 * Normal filesystems would do a "d_delete()" to tell the VFS dcache
600 * that the file no longer exists. However, doing that means that the
601 * VFS layer can turn the dentry into a negative dentry. We don't want
Ian Kentf50b6f82007-02-20 13:58:10 -0800602 * this, because the unlink is probably the result of an expire.
Ian Kent5f6f4f22008-07-23 21:30:09 -0700603 * We simply d_drop it and add it to a expiring list in the super block,
604 * which allows the dentry lookup to check for an incomplete expire.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700605 *
606 * If a process is blocked on the dentry waiting for the expire to finish,
607 * it will invalidate the dentry and try to mount with a new one.
608 *
609 * Also see autofs4_dir_rmdir()..
610 */
611static int autofs4_dir_unlink(struct inode *dir, struct dentry *dentry)
612{
613 struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
614 struct autofs_info *ino = autofs4_dentry_ino(dentry);
Ian Kent1aff3c82006-03-27 01:14:46 -0800615 struct autofs_info *p_ino;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700616
617 /* This allows root to remove symlinks */
Sukadev Bhattiprolud78e53c2007-05-10 22:23:06 -0700618 if (!autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN))
Zhao Hongjiang41735812013-02-20 13:13:55 +1100619 return -EPERM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700620
Ian Kent1aff3c82006-03-27 01:14:46 -0800621 if (atomic_dec_and_test(&ino->count)) {
622 p_ino = autofs4_dentry_ino(dentry->d_parent);
Rui Xiangc24930a2014-01-23 15:55:00 -0800623 if (p_ino && !IS_ROOT(dentry))
Ian Kent1aff3c82006-03-27 01:14:46 -0800624 atomic_dec(&p_ino->count);
625 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700626 dput(ino->dentry);
627
628 dentry->d_inode->i_size = 0;
Dave Hansence71ec32006-09-30 23:29:06 -0700629 clear_nlink(dentry->d_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700630
631 dir->i_mtime = CURRENT_TIME;
632
Ian Kente7854722011-03-25 01:51:31 +0800633 spin_lock(&sbi->lookup_lock);
634 __autofs4_add_expiring(dentry);
Ian Kent0259cb02012-12-14 10:23:29 +0800635 d_drop(dentry);
Ian Kente7854722011-03-25 01:51:31 +0800636 spin_unlock(&sbi->lookup_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700637
638 return 0;
639}
640
Ian Kentdd89f902011-01-14 18:46:35 +0000641/*
642 * Version 4 of autofs provides a pseudo direct mount implementation
643 * that relies on directories at the leaves of a directory tree under
644 * an indirect mount to trigger mounts. To allow for this we need to
645 * set the DMANAGED_AUTOMOUNT and DMANAGED_TRANSIT flags on the leaves
646 * of the directory tree. There is no need to clear the automount flag
647 * following a mount or restore it after an expire because these mounts
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300648 * are always covered. However, it is necessary to ensure that these
Ian Kentdd89f902011-01-14 18:46:35 +0000649 * flags are clear on non-empty directories to avoid unnecessary calls
650 * during path walks.
651 */
652static void autofs_set_leaf_automount_flags(struct dentry *dentry)
653{
654 struct dentry *parent;
655
656 /* root and dentrys in the root are already handled */
657 if (IS_ROOT(dentry->d_parent))
658 return;
659
660 managed_dentry_set_managed(dentry);
661
662 parent = dentry->d_parent;
663 /* only consider parents below dentrys in the root */
664 if (IS_ROOT(parent->d_parent))
665 return;
666 managed_dentry_clear_managed(parent);
667 return;
668}
669
670static void autofs_clear_leaf_automount_flags(struct dentry *dentry)
671{
672 struct list_head *d_child;
673 struct dentry *parent;
674
675 /* flags for dentrys in the root are handled elsewhere */
676 if (IS_ROOT(dentry->d_parent))
677 return;
678
679 managed_dentry_clear_managed(dentry);
680
681 parent = dentry->d_parent;
682 /* only consider parents below dentrys in the root */
683 if (IS_ROOT(parent->d_parent))
684 return;
Al Viro946e51f2014-10-26 19:19:16 -0400685 d_child = &dentry->d_child;
Ian Kentdd89f902011-01-14 18:46:35 +0000686 /* Set parent managed if it's becoming empty */
687 if (d_child->next == &parent->d_subdirs &&
688 d_child->prev == &parent->d_subdirs)
689 managed_dentry_set_managed(parent);
690 return;
691}
692
Linus Torvalds1da177e2005-04-16 15:20:36 -0700693static int autofs4_dir_rmdir(struct inode *dir, struct dentry *dentry)
694{
695 struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
696 struct autofs_info *ino = autofs4_dentry_ino(dentry);
Ian Kent1aff3c82006-03-27 01:14:46 -0800697 struct autofs_info *p_ino;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700698
Al Viroa4555892014-10-21 20:11:25 -0400699 DPRINTK("dentry %p, removing %pd", dentry, dentry);
Ian Kentf50b6f82007-02-20 13:58:10 -0800700
Linus Torvalds1da177e2005-04-16 15:20:36 -0700701 if (!autofs4_oz_mode(sbi))
702 return -EACCES;
703
Nick Piggin2fd6b7f2011-01-07 17:49:34 +1100704 spin_lock(&sbi->lookup_lock);
Ian Kent0259cb02012-12-14 10:23:29 +0800705 if (!simple_empty(dentry)) {
Nick Piggin2fd6b7f2011-01-07 17:49:34 +1100706 spin_unlock(&sbi->lookup_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700707 return -ENOTEMPTY;
708 }
Nick Piggin2fd6b7f2011-01-07 17:49:34 +1100709 __autofs4_add_expiring(dentry);
Ian Kent0259cb02012-12-14 10:23:29 +0800710 d_drop(dentry);
Ian Kente7854722011-03-25 01:51:31 +0800711 spin_unlock(&sbi->lookup_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700712
Ian Kentdd89f902011-01-14 18:46:35 +0000713 if (sbi->version < 5)
714 autofs_clear_leaf_automount_flags(dentry);
715
Ian Kent1aff3c82006-03-27 01:14:46 -0800716 if (atomic_dec_and_test(&ino->count)) {
717 p_ino = autofs4_dentry_ino(dentry->d_parent);
718 if (p_ino && dentry->d_parent != dentry)
719 atomic_dec(&p_ino->count);
720 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700721 dput(ino->dentry);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700722 dentry->d_inode->i_size = 0;
Dave Hansence71ec32006-09-30 23:29:06 -0700723 clear_nlink(dentry->d_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700724
725 if (dir->i_nlink)
Dave Hansen9a53c3a2006-09-30 23:29:03 -0700726 drop_nlink(dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700727
728 return 0;
729}
730
Al Viro18bb1db2011-07-26 01:41:39 -0400731static int autofs4_dir_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700732{
733 struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
734 struct autofs_info *ino = autofs4_dentry_ino(dentry);
Ian Kent1aff3c82006-03-27 01:14:46 -0800735 struct autofs_info *p_ino;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700736 struct inode *inode;
737
Sukadev Bhattiprolud78e53c2007-05-10 22:23:06 -0700738 if (!autofs4_oz_mode(sbi))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700739 return -EACCES;
740
Al Viroa4555892014-10-21 20:11:25 -0400741 DPRINTK("dentry %p, creating %pd", dentry, dentry);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700742
Al Viro5a37db32011-01-16 18:29:35 -0500743 BUG_ON(!ino);
744
Al Viro26e6c912011-01-16 18:43:40 -0500745 autofs4_clean_ino(ino);
Ian Kent25767372008-07-23 21:30:12 -0700746
Al Viro4b1ae272010-03-03 12:58:31 -0500747 autofs4_del_active(dentry);
748
Al Viro726a5e02011-01-16 17:43:52 -0500749 inode = autofs4_get_inode(dir->i_sb, S_IFDIR | 0555);
Al Viro5a37db32011-01-16 18:29:35 -0500750 if (!inode)
Ian Kent25767372008-07-23 21:30:12 -0700751 return -ENOMEM;
Ian Kent1864f7b2007-08-22 14:01:54 -0700752 d_add(dentry, inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700753
Ian Kentdd89f902011-01-14 18:46:35 +0000754 if (sbi->version < 5)
755 autofs_set_leaf_automount_flags(dentry);
756
Al Viro5a37db32011-01-16 18:29:35 -0500757 dget(dentry);
Ian Kent1aff3c82006-03-27 01:14:46 -0800758 atomic_inc(&ino->count);
759 p_ino = autofs4_dentry_ino(dentry->d_parent);
Rui Xiangc24930a2014-01-23 15:55:00 -0800760 if (p_ino && !IS_ROOT(dentry))
Ian Kent1aff3c82006-03-27 01:14:46 -0800761 atomic_inc(&p_ino->count);
Dave Hansend8c76e62006-09-30 23:29:04 -0700762 inc_nlink(dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700763 dir->i_mtime = CURRENT_TIME;
764
765 return 0;
766}
767
768/* Get/set timeout ioctl() operation */
Arnd Bergmannc9243f52010-07-04 00:15:07 +0200769#ifdef CONFIG_COMPAT
770static inline int autofs4_compat_get_set_timeout(struct autofs_sb_info *sbi,
771 compat_ulong_t __user *p)
772{
773 int rv;
774 unsigned long ntimeout;
775
776 if ((rv = get_user(ntimeout, p)) ||
777 (rv = put_user(sbi->exp_timeout/HZ, p)))
778 return rv;
779
780 if (ntimeout > UINT_MAX/HZ)
781 sbi->exp_timeout = 0;
782 else
783 sbi->exp_timeout = ntimeout * HZ;
784
785 return 0;
786}
787#endif
788
Linus Torvalds1da177e2005-04-16 15:20:36 -0700789static inline int autofs4_get_set_timeout(struct autofs_sb_info *sbi,
790 unsigned long __user *p)
791{
792 int rv;
793 unsigned long ntimeout;
794
Sukadev Bhattiprolud78e53c2007-05-10 22:23:06 -0700795 if ((rv = get_user(ntimeout, p)) ||
796 (rv = put_user(sbi->exp_timeout/HZ, p)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700797 return rv;
798
Sukadev Bhattiprolud78e53c2007-05-10 22:23:06 -0700799 if (ntimeout > ULONG_MAX/HZ)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700800 sbi->exp_timeout = 0;
801 else
802 sbi->exp_timeout = ntimeout * HZ;
803
804 return 0;
805}
806
807/* Return protocol version */
808static inline int autofs4_get_protover(struct autofs_sb_info *sbi, int __user *p)
809{
810 return put_user(sbi->version, p);
811}
812
813/* Return protocol sub version */
814static inline int autofs4_get_protosubver(struct autofs_sb_info *sbi, int __user *p)
815{
816 return put_user(sbi->sub_version, p);
817}
818
819/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700820* Tells the daemon whether it can umount the autofs mount.
821*/
822static inline int autofs4_ask_umount(struct vfsmount *mnt, int __user *p)
823{
824 int status = 0;
825
Ian Kente3474a82006-03-27 01:14:51 -0800826 if (may_umount(mnt))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700827 status = 1;
828
829 DPRINTK("returning %d", status);
830
831 status = put_user(status, p);
832
833 return status;
834}
835
836/* Identify autofs4_dentries - this is so we can tell if there's
837 an extra dentry refcount or not. We only hold a refcount on the
838 dentry if its non-negative (ie, d_inode != NULL)
839*/
840int is_autofs4_dentry(struct dentry *dentry)
841{
842 return dentry && dentry->d_inode &&
David Howellsb650c852011-01-15 10:51:57 +0000843 dentry->d_op == &autofs4_dentry_operations &&
Linus Torvalds1da177e2005-04-16 15:20:36 -0700844 dentry->d_fsdata != NULL;
845}
846
847/*
848 * ioctl()'s on the root directory is the chief method for the daemon to
849 * generate kernel reactions
850 */
Frederic Weisbecker3663df72010-05-19 15:08:17 +0200851static int autofs4_root_ioctl_unlocked(struct inode *inode, struct file *filp,
852 unsigned int cmd, unsigned long arg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700853{
854 struct autofs_sb_info *sbi = autofs4_sbi(inode->i_sb);
855 void __user *p = (void __user *)arg;
856
857 DPRINTK("cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u",
Pavel Emelianova47afb02007-10-18 23:39:46 -0700858 cmd,arg,sbi,task_pgrp_nr(current));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700859
Sukadev Bhattiprolud78e53c2007-05-10 22:23:06 -0700860 if (_IOC_TYPE(cmd) != _IOC_TYPE(AUTOFS_IOC_FIRST) ||
861 _IOC_NR(cmd) - _IOC_NR(AUTOFS_IOC_FIRST) >= AUTOFS_IOC_COUNT)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700862 return -ENOTTY;
863
Sukadev Bhattiprolud78e53c2007-05-10 22:23:06 -0700864 if (!autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700865 return -EPERM;
866
867 switch(cmd) {
868 case AUTOFS_IOC_READY: /* Wait queue: go ahead and retry */
869 return autofs4_wait_release(sbi,(autofs_wqt_t)arg,0);
870 case AUTOFS_IOC_FAIL: /* Wait queue: fail with ENOENT */
871 return autofs4_wait_release(sbi,(autofs_wqt_t)arg,-ENOENT);
872 case AUTOFS_IOC_CATATONIC: /* Enter catatonic mode (daemon shutdown) */
873 autofs4_catatonic_mode(sbi);
874 return 0;
875 case AUTOFS_IOC_PROTOVER: /* Get protocol version */
876 return autofs4_get_protover(sbi, p);
877 case AUTOFS_IOC_PROTOSUBVER: /* Get protocol sub version */
878 return autofs4_get_protosubver(sbi, p);
879 case AUTOFS_IOC_SETTIMEOUT:
880 return autofs4_get_set_timeout(sbi, p);
Arnd Bergmannc9243f52010-07-04 00:15:07 +0200881#ifdef CONFIG_COMPAT
882 case AUTOFS_IOC_SETTIMEOUT32:
883 return autofs4_compat_get_set_timeout(sbi, p);
884#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700885
Linus Torvalds1da177e2005-04-16 15:20:36 -0700886 case AUTOFS_IOC_ASKUMOUNT:
Josef "Jeff" Sipeka4669ed2006-12-08 02:36:46 -0800887 return autofs4_ask_umount(filp->f_path.mnt, p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700888
889 /* return a single thing to expire */
890 case AUTOFS_IOC_EXPIRE:
Josef "Jeff" Sipeka4669ed2006-12-08 02:36:46 -0800891 return autofs4_expire_run(inode->i_sb,filp->f_path.mnt,sbi, p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700892 /* same as above, but can send multiple expires through pipe */
893 case AUTOFS_IOC_EXPIRE_MULTI:
Josef "Jeff" Sipeka4669ed2006-12-08 02:36:46 -0800894 return autofs4_expire_multi(inode->i_sb,filp->f_path.mnt,sbi, p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700895
896 default:
897 return -ENOSYS;
898 }
899}
Frederic Weisbecker3663df72010-05-19 15:08:17 +0200900
901static long autofs4_root_ioctl(struct file *filp,
902 unsigned int cmd, unsigned long arg)
903{
Al Viro496ad9a2013-01-23 17:07:38 -0500904 struct inode *inode = file_inode(filp);
Ian Kentde47de72010-12-07 13:04:00 +0800905 return autofs4_root_ioctl_unlocked(inode, filp, cmd, arg);
Frederic Weisbecker3663df72010-05-19 15:08:17 +0200906}
Arnd Bergmannc9243f52010-07-04 00:15:07 +0200907
908#ifdef CONFIG_COMPAT
909static long autofs4_root_compat_ioctl(struct file *filp,
910 unsigned int cmd, unsigned long arg)
911{
Al Viro496ad9a2013-01-23 17:07:38 -0500912 struct inode *inode = file_inode(filp);
Arnd Bergmannc9243f52010-07-04 00:15:07 +0200913 int ret;
914
Arnd Bergmannc9243f52010-07-04 00:15:07 +0200915 if (cmd == AUTOFS_IOC_READY || cmd == AUTOFS_IOC_FAIL)
916 ret = autofs4_root_ioctl_unlocked(inode, filp, cmd, arg);
917 else
918 ret = autofs4_root_ioctl_unlocked(inode, filp, cmd,
919 (unsigned long)compat_ptr(arg));
Arnd Bergmannc9243f52010-07-04 00:15:07 +0200920
921 return ret;
922}
923#endif