1 /* $NetBSD: amfs_linkx.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_linkx.c 39 * 40 */ 41 42 /* 43 * Symbol-link file system, with test that the target of the link exists. 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_linkx_mount(am_node *mp, mntfs *mf); 54 static int amfs_linkx_umount(am_node *mp, mntfs *mf); 55 56 /* 57 * linkx operations 58 */ 59 struct am_ops amfs_linkx_ops = 60 { 61 "linkx", 62 amfs_link_match, 63 0, /* amfs_linkx_init */ 64 amfs_linkx_mount, 65 amfs_linkx_umount, 66 amfs_error_lookup_child, 67 amfs_error_mount_child, 68 amfs_error_readdir, 69 0, /* amfs_linkx_readlink */ 70 0, /* amfs_linkx_mounted */ 71 0, /* amfs_linkx_umounted */ 72 amfs_generic_find_srvr, 73 0, /* amfs_linkx_get_wchan */ 74 FS_MBACKGROUND, 75 #ifdef HAVE_FS_AUTOFS 76 AUTOFS_LINKX_FS_FLAGS, 77 #endif /* HAVE_FS_AUTOFS */ 78 }; 79 80 81 static int 82 amfs_linkx_mount(am_node *mp, mntfs *mf) 83 { 84 /* 85 * Check for existence of target. 86 */ 87 struct stat stb; 88 char *ln; 89 90 if (mp->am_link) 91 ln = mp->am_link; 92 else /* should never occur */ 93 ln = mf->mf_mount; 94 95 /* 96 * Use lstat, not stat, since we don't 97 * want to know if the ultimate target of 98 * a symlink chain exists, just the first. 99 */ 100 if (lstat(ln, &stb) < 0) 101 return errno; 102 103 return 0; 104 } 105 106 107 static int 108 amfs_linkx_umount(am_node *mp, mntfs *mf) 109 { 110 return 0; 111 } 112