1 /*
2 * Copyright (c) 1997-2006 Erez Zadok
3 * Copyright (c) 1990 Jan-Simon Pendry
4 * Copyright (c) 1990 Imperial College of Science, Technology & Medicine
5 * Copyright (c) 1990 The Regents of the University of California.
6 * All rights reserved.
7 *
8 * This code is derived from software contributed to Berkeley by
9 * Jan-Simon Pendry at Imperial College, London.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. All advertising materials mentioning features or use of this software
20 * must display the following acknowledgment:
21 * This product includes software developed by the University of
22 * California, Berkeley and its contributors.
23 * 4. Neither the name of the University nor the names of its contributors
24 * may be used to endorse or promote products derived from this software
25 * without specific prior written permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37 * SUCH DAMAGE.
38 *
39 *
40 * File: am-utils/amd/amfs_union.c
41 *
42 */
43
44 /*
45 * Union automounter file system
46 */
47
48 #ifdef HAVE_CONFIG_H
49 # include <config.h>
50 #endif /* HAVE_CONFIG_H */
51 #include <am_defs.h>
52 #include <amd.h>
53
54 /****************************************************************************
55 *** FORWARD DEFINITIONS ***
56 ****************************************************************************/
57 static int create_amfs_union_node(char *dir, opaque_t arg);
58 static void amfs_union_mounted(mntfs *mf);
59
60
61 /****************************************************************************
62 *** OPS STRUCTURES ***
63 ****************************************************************************/
64 am_ops amfs_union_ops =
65 {
66 "union",
67 amfs_generic_match,
68 0, /* amfs_union_init */
69 amfs_toplvl_mount,
70 amfs_toplvl_umount,
71 amfs_generic_lookup_child,
72 amfs_generic_mount_child,
73 amfs_generic_readdir,
74 0, /* amfs_union_readlink */
75 amfs_union_mounted,
76 0, /* amfs_union_umounted */
77 amfs_generic_find_srvr,
78 0, /* amfs_union_get_wchan */
79 FS_MKMNT | FS_NOTIMEOUT | FS_BACKGROUND | FS_AMQINFO | FS_DIRECTORY,
80 #ifdef HAVE_FS_AUTOFS
81 AUTOFS_UNION_FS_FLAGS,
82 #endif /* HAVE_FS_AUTOFS */
83 };
84
85
86 /*
87 * Create a reference to a union'ed entry
88 * XXX: this function may not be used anywhere...
89 */
90 static int
create_amfs_union_node(char * dir,opaque_t arg)91 create_amfs_union_node(char *dir, opaque_t arg)
92 {
93 if (!STREQ(dir, "/defaults")) {
94 int error = 0;
95 am_node *am;
96 am = amfs_generic_lookup_child(arg, dir, &error, VLOOK_CREATE);
97 if (am && error < 0)
98 am = amfs_generic_mount_child(am, &error);
99 if (error > 0) {
100 errno = error; /* XXX */
101 plog(XLOG_ERROR, "unionfs: could not mount %s: %m", dir);
102 }
103 return error;
104 }
105 return 0;
106 }
107
108
109 static void
amfs_union_mounted(mntfs * mf)110 amfs_union_mounted(mntfs *mf)
111 {
112 int index;
113 am_node *mp;
114
115 amfs_mkcacheref(mf);
116
117 /*
118 * Having made the union mount point,
119 * populate all the entries...
120 */
121 for (mp = get_first_exported_ap(&index);
122 mp;
123 mp = get_next_exported_ap(&index)) {
124 if (mp->am_mnt == mf) {
125 /* return value from create_amfs_union_node is ignored by mapc_keyiter */
126 (void) mapc_keyiter((mnt_map *) mp->am_mnt->mf_private,
127 create_amfs_union_node,
128 mp);
129 break;
130 }
131 }
132 }
133