external/bsd/am-utils/dist/amd/amfs_union.c

   1 /*      $NetBSD$        */
   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 }