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 ****************************************************************************/
57static int create_amfs_union_node(char *dir, opaque_t arg);
58static void amfs_union_mounted(mntfs *mf);
59
60
61/****************************************************************************
62 *** OPS STRUCTURES                                                       ***
63 ****************************************************************************/
64am_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 */
90static int
91create_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
109static void
110amfs_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