1 /* $NetBSD: amfs_union.c,v 1.1.1.2 2009/03/20 20:26:49 christos Exp $ */ 2 3 /* 4 * Copyright (c) 1997-2009 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. All advertising materials mentioning features or use of this software 22 * must display the following acknowledgment: 23 * This product includes software developed by the University of 24 * California, Berkeley and its contributors. 25 * 4. Neither the name of the University nor the names of its contributors 26 * may be used to endorse or promote products derived from this software 27 * without specific prior written permission. 28 * 29 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 30 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 31 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 32 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 33 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 34 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 35 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 37 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 38 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 39 * SUCH DAMAGE. 40 * 41 * 42 * File: am-utils/amd/amfs_union.c 43 * 44 */ 45 46 /* 47 * Union automounter file system 48 */ 49 50 #ifdef HAVE_CONFIG_H 51 # include <config.h> 52 #endif /* HAVE_CONFIG_H */ 53 #include <am_defs.h> 54 #include <amd.h> 55 56 /**************************************************************************** 57 *** FORWARD DEFINITIONS *** 58 ****************************************************************************/ 59 static int create_amfs_union_node(char *dir, opaque_t arg); 60 static void amfs_union_mounted(mntfs *mf); 61 62 63 /**************************************************************************** 64 *** OPS STRUCTURES *** 65 ****************************************************************************/ 66 am_ops amfs_union_ops = 67 { 68 "union", 69 amfs_generic_match, 70 0, /* amfs_union_init */ 71 amfs_toplvl_mount, 72 amfs_toplvl_umount, 73 amfs_generic_lookup_child, 74 amfs_generic_mount_child, 75 amfs_generic_readdir, 76 0, /* amfs_union_readlink */ 77 amfs_union_mounted, 78 0, /* amfs_union_umounted */ 79 amfs_generic_find_srvr, 80 0, /* amfs_union_get_wchan */ 81 FS_MKMNT | FS_NOTIMEOUT | FS_BACKGROUND | FS_AMQINFO | FS_DIRECTORY, 82 #ifdef HAVE_FS_AUTOFS 83 AUTOFS_UNION_FS_FLAGS, 84 #endif /* HAVE_FS_AUTOFS */ 85 }; 86 87 88 /* 89 * Create a reference to a union'ed entry 90 * XXX: this function may not be used anywhere... 91 */ 92 static int 93 create_amfs_union_node(char *dir, opaque_t arg) 94 { 95 if (!STREQ(dir, "/defaults")) { 96 int error = 0; 97 am_node *am; 98 am = amfs_generic_lookup_child(arg, dir, &error, VLOOK_CREATE); 99 if (am && error < 0) 100 am = amfs_generic_mount_child(am, &error); 101 if (error > 0) { 102 errno = error; /* XXX */ 103 plog(XLOG_ERROR, "unionfs: could not mount %s: %m", dir); 104 } 105 return error; 106 } 107 return 0; 108 } 109 110 111 static void 112 amfs_union_mounted(mntfs *mf) 113 { 114 int index; 115 am_node *mp; 116 117 amfs_mkcacheref(mf); 118 119 /* 120 * Having made the union mount point, 121 * populate all the entries... 122 */ 123 for (mp = get_first_exported_ap(&index); 124 mp; 125 mp = get_next_exported_ap(&index)) { 126 if (mp->am_mnt == mf) { 127 /* return value from create_amfs_union_node is ignored by mapc_keyiter */ 128 (void) mapc_keyiter((mnt_map *) mp->am_mnt->mf_private, 129 create_amfs_union_node, 130 mp); 131 break; 132 } 133 } 134 } 135