xref: /freebsd/sys/fs/autofs/autofs_vfsops.c (revision a831d7d1c538b93ffec095657d9a6e6e778db195)
1 /*-
2  * Copyright (c) 2014 The FreeBSD Foundation
3  * All rights reserved.
4  *
5  * This software was developed by Edward Tomasz Napierala under sponsorship
6  * from the FreeBSD Foundation.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  */
30 
31 #include <sys/cdefs.h>
32  __FBSDID("$FreeBSD$");
33 
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/conf.h>
37 #include <sys/condvar.h>
38 #include <sys/ioccom.h>
39 #include <sys/kernel.h>
40 #include <sys/module.h>
41 #include <sys/mount.h>
42 #include <sys/sx.h>
43 #include <sys/taskqueue.h>
44 #include <sys/vnode.h>
45 
46 #include <fs/autofs/autofs.h>
47 
48 static const char *autofs_opts[] = {
49 	"from", "master_options", "master_prefix", NULL
50 };
51 
52 extern struct autofs_softc	*autofs_softc;
53 
54 static int
55 autofs_mount(struct mount *mp)
56 {
57 	struct autofs_mount *amp;
58 	char *from, *fspath, *options, *prefix;
59 	int error;
60 
61 	if (vfs_filteropt(mp->mnt_optnew, autofs_opts))
62 		return (EINVAL);
63 
64 	if (mp->mnt_flag & MNT_UPDATE) {
65 		autofs_flush(VFSTOAUTOFS(mp));
66 		return (0);
67 	}
68 
69 	if (vfs_getopt(mp->mnt_optnew, "from", (void **)&from, NULL))
70 		return (EINVAL);
71 
72 	if (vfs_getopt(mp->mnt_optnew, "fspath", (void **)&fspath, NULL))
73 		return (EINVAL);
74 
75 	if (vfs_getopt(mp->mnt_optnew, "master_options", (void **)&options, NULL))
76 		return (EINVAL);
77 
78 	if (vfs_getopt(mp->mnt_optnew, "master_prefix", (void **)&prefix, NULL))
79 		return (EINVAL);
80 
81 	amp = malloc(sizeof(*amp), M_AUTOFS, M_WAITOK | M_ZERO);
82 	mp->mnt_data = amp;
83 	amp->am_mp = mp;
84 	strlcpy(amp->am_from, from, sizeof(amp->am_from));
85 	strlcpy(amp->am_mountpoint, fspath, sizeof(amp->am_mountpoint));
86 	strlcpy(amp->am_options, options, sizeof(amp->am_options));
87 	strlcpy(amp->am_prefix, prefix, sizeof(amp->am_prefix));
88 	sx_init(&amp->am_lock, "autofslk");
89 	amp->am_last_fileno = 1;
90 
91 	vfs_getnewfsid(mp);
92 
93 	MNT_ILOCK(mp);
94 	mp->mnt_kern_flag |= MNTK_LOOKUP_SHARED;
95 	MNT_IUNLOCK(mp);
96 
97 	AUTOFS_XLOCK(amp);
98 	error = autofs_node_new(NULL, amp, ".", -1, &amp->am_root);
99 	if (error != 0) {
100 		AUTOFS_XUNLOCK(amp);
101 		free(amp, M_AUTOFS);
102 		return (error);
103 	}
104 	AUTOFS_XUNLOCK(amp);
105 
106 	vfs_mountedfrom(mp, from);
107 
108 	return (0);
109 }
110 
111 static int
112 autofs_unmount(struct mount *mp, int mntflags)
113 {
114 	struct autofs_mount *amp;
115 	struct autofs_node *anp;
116 	struct autofs_request *ar;
117 	int error, flags;
118 	bool found;
119 
120 	amp = VFSTOAUTOFS(mp);
121 
122 	flags = 0;
123 	if (mntflags & MNT_FORCE)
124 		flags |= FORCECLOSE;
125 	error = vflush(mp, 0, flags, curthread);
126 	if (error != 0) {
127 		AUTOFS_WARN("vflush failed with error %d", error);
128 		return (error);
129 	}
130 
131 	/*
132 	 * All vnodes are gone, and new one will not appear - so,
133 	 * no new triggerings.  We can iterate over outstanding
134 	 * autofs_requests and terminate them.
135 	 */
136 	for (;;) {
137 		found = false;
138 		sx_xlock(&autofs_softc->sc_lock);
139 		TAILQ_FOREACH(ar, &autofs_softc->sc_requests, ar_next) {
140 			if (ar->ar_mount != amp)
141 				continue;
142 			ar->ar_error = ENXIO;
143 			ar->ar_done = true;
144 			ar->ar_in_progress = false;
145 			found = true;
146 		}
147 		sx_xunlock(&autofs_softc->sc_lock);
148 		if (found == false)
149 			break;
150 
151 		cv_broadcast(&autofs_softc->sc_cv);
152 		pause("autofs_umount", 1);
153 	}
154 
155 	AUTOFS_XLOCK(amp);
156 
157 	/*
158 	 * Not terribly efficient, but at least not recursive.
159 	 */
160 	while (!TAILQ_EMPTY(&amp->am_root->an_children)) {
161 		anp = TAILQ_FIRST(&amp->am_root->an_children);
162 		while (!TAILQ_EMPTY(&anp->an_children))
163 			anp = TAILQ_FIRST(&anp->an_children);
164 		autofs_node_delete(anp);
165 	}
166 	autofs_node_delete(amp->am_root);
167 
168 	mp->mnt_data = NULL;
169 	AUTOFS_XUNLOCK(amp);
170 
171 	sx_destroy(&amp->am_lock);
172 
173 	free(amp, M_AUTOFS);
174 
175 	return (0);
176 }
177 
178 static int
179 autofs_root(struct mount *mp, int flags, struct vnode **vpp)
180 {
181 	struct autofs_mount *amp;
182 	int error;
183 
184 	amp = VFSTOAUTOFS(mp);
185 
186 	error = autofs_node_vn(amp->am_root, mp, flags, vpp);
187 
188 	return (error);
189 }
190 
191 static int
192 autofs_statfs(struct mount *mp, struct statfs *sbp)
193 {
194 
195 	sbp->f_bsize = 512;
196 	sbp->f_iosize = 0;
197 	sbp->f_blocks = 0;
198 	sbp->f_bfree = 0;
199 	sbp->f_bavail = 0;
200 	sbp->f_files = 0;
201 	sbp->f_ffree = 0;
202 
203 	return (0);
204 }
205 
206 static struct vfsops autofs_vfsops = {
207 	.vfs_fhtovp =		NULL, /* XXX */
208 	.vfs_mount =		autofs_mount,
209 	.vfs_unmount =		autofs_unmount,
210 	.vfs_root =		autofs_root,
211 	.vfs_statfs =		autofs_statfs,
212 	.vfs_init =		autofs_init,
213 	.vfs_uninit =		autofs_uninit,
214 };
215 
216 VFS_SET(autofs_vfsops, autofs, VFCF_SYNTHETIC | VFCF_NETWORK);
217 MODULE_VERSION(autofs, 1);
218