1 /* $NetBSD: amfs_union.c,v 1.1.1.3 2015/01/17 16:34:15 christos Exp $ */
2
3 /*
4 * Copyright (c) 1997-2014 Erez Zadok
5 * Copyright (c) 1990 Jan-Simon Pendry
6 * Copyright (c) 1990 Imperial College of Science, Technology & Medicine
7 * Copyright (c) 1990 The Regents of the University of California.
8 * All rights reserved.
9 *
10 * This code is derived from software contributed to Berkeley by
11 * Jan-Simon Pendry at Imperial College, London.
12 *
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
15 * are met:
16 * 1. Redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer.
18 * 2. Redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution.
21 * 3. Neither the name of the University nor the names of its contributors
22 * may be used to endorse or promote products derived from this software
23 * without specific prior written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * SUCH DAMAGE.
36 *
37 *
38 * File: am-utils/amd/amfs_union.c
39 *
40 */
41
42 /*
43 * Union automounter file system
44 */
45
46 #ifdef HAVE_CONFIG_H
47 # include <config.h>
48 #endif /* HAVE_CONFIG_H */
49 #include <am_defs.h>
50 #include <amd.h>
51
52 /****************************************************************************
53 *** FORWARD DEFINITIONS ***
54 ****************************************************************************/
55 static int create_amfs_union_node(char *dir, opaque_t arg);
56 static void amfs_union_mounted(mntfs *mf);
57
58
59 /****************************************************************************
60 *** OPS STRUCTURES ***
61 ****************************************************************************/
62 am_ops amfs_union_ops =
63 {
64 "union",
65 amfs_generic_match,
66 0, /* amfs_union_init */
67 amfs_toplvl_mount,
68 amfs_toplvl_umount,
69 amfs_generic_lookup_child,
70 amfs_generic_mount_child,
71 amfs_generic_readdir,
72 0, /* amfs_union_readlink */
73 amfs_union_mounted,
74 0, /* amfs_union_umounted */
75 amfs_generic_find_srvr,
76 0, /* amfs_union_get_wchan */
77 FS_MKMNT | FS_NOTIMEOUT | FS_BACKGROUND | FS_AMQINFO | FS_DIRECTORY,
78 #ifdef HAVE_FS_AUTOFS
79 AUTOFS_UNION_FS_FLAGS,
80 #endif /* HAVE_FS_AUTOFS */
81 };
82
83
84 /*
85 * Create a reference to a union'ed entry
86 * XXX: this function may not be used anywhere...
87 */
88 static int
create_amfs_union_node(char * dir,opaque_t arg)89 create_amfs_union_node(char *dir, opaque_t arg)
90 {
91 if (!STREQ(dir, "/defaults")) {
92 int error = 0;
93 am_node *am;
94 am = amfs_generic_lookup_child(arg, dir, &error, VLOOK_CREATE);
95 if (am && error < 0)
96 (void)amfs_generic_mount_child(am, &error);
97 if (error > 0) {
98 errno = error; /* XXX */
99 plog(XLOG_ERROR, "unionfs: could not mount %s: %m", dir);
100 }
101 return error;
102 }
103 return 0;
104 }
105
106
107 static void
amfs_union_mounted(mntfs * mf)108 amfs_union_mounted(mntfs *mf)
109 {
110 int index;
111 am_node *mp;
112
113 amfs_mkcacheref(mf);
114
115 /*
116 * Having made the union mount point,
117 * populate all the entries...
118 */
119 for (mp = get_first_exported_ap(&index);
120 mp;
121 mp = get_next_exported_ap(&index)) {
122 if (mp->am_al->al_mnt == mf) {
123 /* return value from create_amfs_union_node is ignored by mapc_keyiter */
124 (void) mapc_keyiter((mnt_map *) mp->am_al->al_mnt->mf_private,
125 create_amfs_union_node,
126 mp);
127 break;
128 }
129 }
130 }
131