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