xref: /freebsd/sys/fs/autofs/autofs_vfsops.c (revision 19fae0f66023a97a9b464b3beeeabb2081f575b3)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2014 The FreeBSD Foundation
5  *
6  * This software was developed by Edward Tomasz Napierala under sponsorship
7  * from the FreeBSD Foundation.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  *
30  */
31 
32 #include <sys/cdefs.h>
33  __FBSDID("$FreeBSD$");
34 
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/conf.h>
38 #include <sys/condvar.h>
39 #include <sys/ioccom.h>
40 #include <sys/kernel.h>
41 #include <sys/module.h>
42 #include <sys/mount.h>
43 #include <sys/stat.h>
44 #include <sys/sx.h>
45 #include <sys/taskqueue.h>
46 #include <sys/tree.h>
47 #include <sys/vnode.h>
48 
49 #include <fs/autofs/autofs.h>
50 
51 static const char *autofs_opts[] = {
52 	"from", "master_options", "master_prefix", NULL
53 };
54 
55 extern struct autofs_softc	*autofs_softc;
56 
57 static int
58 autofs_mount(struct mount *mp)
59 {
60 	struct autofs_mount *amp;
61 	char *from, *fspath, *options, *prefix;
62 	int error;
63 
64 	if (vfs_filteropt(mp->mnt_optnew, autofs_opts))
65 		return (EINVAL);
66 
67 	if (mp->mnt_flag & MNT_UPDATE) {
68 		autofs_flush(VFSTOAUTOFS(mp));
69 		return (0);
70 	}
71 
72 	if (vfs_getopt(mp->mnt_optnew, "from", (void **)&from, NULL))
73 		return (EINVAL);
74 
75 	if (vfs_getopt(mp->mnt_optnew, "fspath", (void **)&fspath, NULL))
76 		return (EINVAL);
77 
78 	if (vfs_getopt(mp->mnt_optnew, "master_options", (void **)&options, NULL))
79 		return (EINVAL);
80 
81 	if (vfs_getopt(mp->mnt_optnew, "master_prefix", (void **)&prefix, NULL))
82 		return (EINVAL);
83 
84 	amp = malloc(sizeof(*amp), M_AUTOFS, M_WAITOK | M_ZERO);
85 	mp->mnt_data = amp;
86 	amp->am_mp = mp;
87 	strlcpy(amp->am_from, from, sizeof(amp->am_from));
88 	strlcpy(amp->am_mountpoint, fspath, sizeof(amp->am_mountpoint));
89 	strlcpy(amp->am_options, options, sizeof(amp->am_options));
90 	strlcpy(amp->am_prefix, prefix, sizeof(amp->am_prefix));
91 	sx_init(&amp->am_lock, "autofslk");
92 	amp->am_last_fileno = 1;
93 
94 	vfs_getnewfsid(mp);
95 
96 	MNT_ILOCK(mp);
97 	mp->mnt_kern_flag |= MNTK_LOOKUP_SHARED;
98 	MNT_IUNLOCK(mp);
99 
100 	AUTOFS_XLOCK(amp);
101 	error = autofs_node_new(NULL, amp, ".", -1, &amp->am_root);
102 	if (error != 0) {
103 		AUTOFS_XUNLOCK(amp);
104 		free(amp, M_AUTOFS);
105 		return (error);
106 	}
107 	AUTOFS_XUNLOCK(amp);
108 
109 	vfs_mountedfrom(mp, from);
110 
111 	return (0);
112 }
113 
114 static int
115 autofs_unmount(struct mount *mp, int mntflags)
116 {
117 	struct autofs_mount *amp;
118 	struct autofs_node *anp;
119 	struct autofs_request *ar;
120 	int error, flags;
121 	bool found;
122 
123 	amp = VFSTOAUTOFS(mp);
124 
125 	flags = 0;
126 	if (mntflags & MNT_FORCE)
127 		flags |= FORCECLOSE;
128 	error = vflush(mp, 0, flags, curthread);
129 	if (error != 0) {
130 		AUTOFS_DEBUG("vflush failed with error %d", error);
131 		return (error);
132 	}
133 
134 	/*
135 	 * All vnodes are gone, and new one will not appear - so,
136 	 * no new triggerings.  We can iterate over outstanding
137 	 * autofs_requests and terminate them.
138 	 */
139 	for (;;) {
140 		found = false;
141 		sx_xlock(&autofs_softc->sc_lock);
142 		TAILQ_FOREACH(ar, &autofs_softc->sc_requests, ar_next) {
143 			if (ar->ar_mount != amp)
144 				continue;
145 			ar->ar_error = ENXIO;
146 			ar->ar_done = true;
147 			ar->ar_in_progress = false;
148 			found = true;
149 		}
150 		sx_xunlock(&autofs_softc->sc_lock);
151 		if (found == false)
152 			break;
153 
154 		cv_broadcast(&autofs_softc->sc_cv);
155 		pause("autofs_umount", 1);
156 	}
157 
158 	AUTOFS_XLOCK(amp);
159 
160 	/*
161 	 * Not terribly efficient, but at least not recursive.
162 	 */
163 	while (!RB_EMPTY(&amp->am_root->an_children)) {
164 		anp = RB_MIN(autofs_node_tree, &amp->am_root->an_children);
165 		while (!RB_EMPTY(&anp->an_children))
166 			anp = RB_MIN(autofs_node_tree, &anp->an_children);
167 		autofs_node_delete(anp);
168 	}
169 	autofs_node_delete(amp->am_root);
170 
171 	mp->mnt_data = NULL;
172 	AUTOFS_XUNLOCK(amp);
173 
174 	sx_destroy(&amp->am_lock);
175 
176 	free(amp, M_AUTOFS);
177 
178 	return (0);
179 }
180 
181 static int
182 autofs_root(struct mount *mp, int flags, struct vnode **vpp)
183 {
184 	struct autofs_mount *amp;
185 	int error;
186 
187 	amp = VFSTOAUTOFS(mp);
188 
189 	error = autofs_node_vn(amp->am_root, mp, flags, vpp);
190 
191 	return (error);
192 }
193 
194 static int
195 autofs_statfs(struct mount *mp, struct statfs *sbp)
196 {
197 
198 	sbp->f_bsize = S_BLKSIZE;
199 	sbp->f_iosize = 0;
200 	sbp->f_blocks = 0;
201 	sbp->f_bfree = 0;
202 	sbp->f_bavail = 0;
203 	sbp->f_files = 0;
204 	sbp->f_ffree = 0;
205 
206 	return (0);
207 }
208 
209 static struct vfsops autofs_vfsops = {
210 	.vfs_fhtovp =		NULL, /* XXX */
211 	.vfs_mount =		autofs_mount,
212 	.vfs_unmount =		autofs_unmount,
213 	.vfs_root =		autofs_root,
214 	.vfs_statfs =		autofs_statfs,
215 	.vfs_init =		autofs_init,
216 	.vfs_uninit =		autofs_uninit,
217 };
218 
219 VFS_SET(autofs_vfsops, autofs, VFCF_SYNTHETIC | VFCF_NETWORK);
220 MODULE_VERSION(autofs, 1);
221