xref: /freebsd/sys/fs/autofs/autofs_vfsops.c (revision 09a53ad8f1318c5daae6cfb19d97f4f6459f0013)
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/stat.h>
43 #include <sys/sx.h>
44 #include <sys/taskqueue.h>
45 #include <sys/tree.h>
46 #include <sys/vnode.h>
47 
48 #include <fs/autofs/autofs.h>
49 
50 static const char *autofs_opts[] = {
51 	"from", "master_options", "master_prefix", NULL
52 };
53 
54 extern struct autofs_softc	*autofs_softc;
55 
56 static int
57 autofs_mount(struct mount *mp)
58 {
59 	struct autofs_mount *amp;
60 	char *from, *fspath, *options, *prefix;
61 	int error;
62 
63 	if (vfs_filteropt(mp->mnt_optnew, autofs_opts))
64 		return (EINVAL);
65 
66 	if (mp->mnt_flag & MNT_UPDATE) {
67 		autofs_flush(VFSTOAUTOFS(mp));
68 		return (0);
69 	}
70 
71 	if (vfs_getopt(mp->mnt_optnew, "from", (void **)&from, NULL))
72 		return (EINVAL);
73 
74 	if (vfs_getopt(mp->mnt_optnew, "fspath", (void **)&fspath, NULL))
75 		return (EINVAL);
76 
77 	if (vfs_getopt(mp->mnt_optnew, "master_options", (void **)&options, NULL))
78 		return (EINVAL);
79 
80 	if (vfs_getopt(mp->mnt_optnew, "master_prefix", (void **)&prefix, NULL))
81 		return (EINVAL);
82 
83 	amp = malloc(sizeof(*amp), M_AUTOFS, M_WAITOK | M_ZERO);
84 	mp->mnt_data = amp;
85 	amp->am_mp = mp;
86 	strlcpy(amp->am_from, from, sizeof(amp->am_from));
87 	strlcpy(amp->am_mountpoint, fspath, sizeof(amp->am_mountpoint));
88 	strlcpy(amp->am_options, options, sizeof(amp->am_options));
89 	strlcpy(amp->am_prefix, prefix, sizeof(amp->am_prefix));
90 	sx_init(&amp->am_lock, "autofslk");
91 	amp->am_last_fileno = 1;
92 
93 	vfs_getnewfsid(mp);
94 
95 	MNT_ILOCK(mp);
96 	mp->mnt_kern_flag |= MNTK_LOOKUP_SHARED;
97 	MNT_IUNLOCK(mp);
98 
99 	AUTOFS_XLOCK(amp);
100 	error = autofs_node_new(NULL, amp, ".", -1, &amp->am_root);
101 	if (error != 0) {
102 		AUTOFS_XUNLOCK(amp);
103 		free(amp, M_AUTOFS);
104 		return (error);
105 	}
106 	AUTOFS_XUNLOCK(amp);
107 
108 	vfs_mountedfrom(mp, from);
109 
110 	return (0);
111 }
112 
113 static int
114 autofs_unmount(struct mount *mp, int mntflags)
115 {
116 	struct autofs_mount *amp;
117 	struct autofs_node *anp;
118 	struct autofs_request *ar;
119 	int error, flags;
120 	bool found;
121 
122 	amp = VFSTOAUTOFS(mp);
123 
124 	flags = 0;
125 	if (mntflags & MNT_FORCE)
126 		flags |= FORCECLOSE;
127 	error = vflush(mp, 0, flags, curthread);
128 	if (error != 0) {
129 		AUTOFS_WARN("vflush failed with error %d", error);
130 		return (error);
131 	}
132 
133 	/*
134 	 * All vnodes are gone, and new one will not appear - so,
135 	 * no new triggerings.  We can iterate over outstanding
136 	 * autofs_requests and terminate them.
137 	 */
138 	for (;;) {
139 		found = false;
140 		sx_xlock(&autofs_softc->sc_lock);
141 		TAILQ_FOREACH(ar, &autofs_softc->sc_requests, ar_next) {
142 			if (ar->ar_mount != amp)
143 				continue;
144 			ar->ar_error = ENXIO;
145 			ar->ar_done = true;
146 			ar->ar_in_progress = false;
147 			found = true;
148 		}
149 		sx_xunlock(&autofs_softc->sc_lock);
150 		if (found == false)
151 			break;
152 
153 		cv_broadcast(&autofs_softc->sc_cv);
154 		pause("autofs_umount", 1);
155 	}
156 
157 	AUTOFS_XLOCK(amp);
158 
159 	/*
160 	 * Not terribly efficient, but at least not recursive.
161 	 */
162 	while (!RB_EMPTY(&amp->am_root->an_children)) {
163 		anp = RB_MIN(autofs_node_tree, &amp->am_root->an_children);
164 		while (!RB_EMPTY(&anp->an_children))
165 			anp = RB_MIN(autofs_node_tree, &anp->an_children);
166 		autofs_node_delete(anp);
167 	}
168 	autofs_node_delete(amp->am_root);
169 
170 	mp->mnt_data = NULL;
171 	AUTOFS_XUNLOCK(amp);
172 
173 	sx_destroy(&amp->am_lock);
174 
175 	free(amp, M_AUTOFS);
176 
177 	return (0);
178 }
179 
180 static int
181 autofs_root(struct mount *mp, int flags, struct vnode **vpp)
182 {
183 	struct autofs_mount *amp;
184 	int error;
185 
186 	amp = VFSTOAUTOFS(mp);
187 
188 	error = autofs_node_vn(amp->am_root, mp, flags, vpp);
189 
190 	return (error);
191 }
192 
193 static int
194 autofs_statfs(struct mount *mp, struct statfs *sbp)
195 {
196 
197 	sbp->f_bsize = S_BLKSIZE;
198 	sbp->f_iosize = 0;
199 	sbp->f_blocks = 0;
200 	sbp->f_bfree = 0;
201 	sbp->f_bavail = 0;
202 	sbp->f_files = 0;
203 	sbp->f_ffree = 0;
204 
205 	return (0);
206 }
207 
208 static struct vfsops autofs_vfsops = {
209 	.vfs_fhtovp =		NULL, /* XXX */
210 	.vfs_mount =		autofs_mount,
211 	.vfs_unmount =		autofs_unmount,
212 	.vfs_root =		autofs_root,
213 	.vfs_statfs =		autofs_statfs,
214 	.vfs_init =		autofs_init,
215 	.vfs_uninit =		autofs_uninit,
216 };
217 
218 VFS_SET(autofs_vfsops, autofs, VFCF_SYNTHETIC | VFCF_NETWORK);
219 MODULE_VERSION(autofs, 1);
220