1 /* $NetBSD: amfs_link.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_link.c 39 * 40 */ 41 42 /* 43 * Symbol-link 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 /* forward declarations */ 53 static int amfs_link_mount(am_node *mp, mntfs *mf); 54 static int amfs_link_umount(am_node *mp, mntfs *mf); 55 56 /* 57 * Ops structures 58 */ 59 am_ops amfs_link_ops = 60 { 61 "link", 62 amfs_link_match, 63 0, /* amfs_link_init */ 64 amfs_link_mount, 65 amfs_link_umount, 66 amfs_error_lookup_child, 67 amfs_error_mount_child, 68 amfs_error_readdir, 69 0, /* amfs_link_readlink */ 70 0, /* amfs_link_mounted */ 71 0, /* amfs_link_umounted */ 72 amfs_generic_find_srvr, 73 0, /* nfs_fs_flags */ 74 0, /* amfs_link_get_wchan */ 75 #ifdef HAVE_FS_AUTOFS 76 AUTOFS_LINK_FS_FLAGS, 77 #endif /* HAVE_FS_AUTOFS */ 78 }; 79 80 81 /* 82 * SFS needs a link. 83 */ 84 char * 85 amfs_link_match(am_opts *fo) 86 { 87 88 if (!fo->opt_fs) { 89 plog(XLOG_USER, "link: no fs specified"); 90 return 0; 91 } 92 93 /* 94 * If the link target points to another mount point, then we could 95 * end up with an unpleasant situation, where the link f/s simply 96 * "assumes" the mntfs of that mount point. 97 * 98 * For example, if the link points to /usr, and /usr is a real ufs 99 * filesystem, then the link f/s will use the inherited ufs mntfs, 100 * and the end result will be that it will become unmountable. 101 * 102 * To prevent this, we use a hack: we prepend a dot ('.') to opt_fs if 103 * its original value was an absolute path, so that it will never match 104 * any other mntfs. 105 * 106 * XXX: a less hacky solution should be used... 107 */ 108 if (fo->opt_fs[0] == '/') { 109 char *link_hack = str3cat(NULL, ".", fo->opt_fs, ""); 110 if (fo->opt_sublink == NULL || fo->opt_sublink[0] == '\0') 111 fo->opt_sublink = xstrdup(fo->opt_fs); 112 XFREE(fo->opt_fs); 113 fo->opt_fs = link_hack; 114 } 115 116 return xstrdup(fo->opt_fs); 117 } 118 119 120 static int 121 amfs_link_mount(am_node *mp, mntfs *mf) 122 { 123 return 0; 124 } 125 126 127 static int 128 amfs_link_umount(am_node *mp, mntfs *mf) 129 { 130 return 0; 131 } 132