external/bsd/am-utils/dist/conf/umount/umount_default.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/conf/umount/umount_default.c
  43  *
  44  */
  45
  46 /*
  47  * Default method of unmounting filesystems.
  48  */
  49
  50 #ifdef HAVE_CONFIG_H
  51 # include <config.h>
  52 #endif /* HAVE_CONFIG_H */
  53 #include <am_defs.h>
  54 #include <amu.h>
  55
  56
  57 int
  58 umount_fs(char *mntdir, const char *mnttabname, u_int unmount_flags)
  59 {
  60   mntlist *mlist, *mp, *mp_save = NULL;
  61   int error = 0;
  62
  63   mp = mlist = read_mtab(mntdir, mnttabname);
  64
  65   /*
  66    * Search the mount table looking for
  67    * the correct (ie last) matching entry
  68    */
  69   while (mp) {
  70     if (STREQ(mp->mnt->mnt_dir, mntdir))
  71       mp_save = mp;
  72     mp = mp->mnext;
  73   }
  74
  75   if (mp_save) {
  76     dlog("Trying unmount(%s)", mp_save->mnt->mnt_dir);
  77
  78 #ifdef MOUNT_TABLE_ON_FILE
  79     /*
  80      * This unmount may hang leaving this process with an exclusive lock on
  81      * /etc/mtab. Therefore it is necessary to unlock mtab, do the unmount,
  82      * then lock mtab (again) and reread it and finally update it.
  83      */
  84     unlock_mntlist();
  85 #endif /* MOUNT_TABLE_ON_FILE */
  86
  87 #ifdef NEED_AUTOFS_SPACE_HACK
  88     if (unmount_flags & AMU_UMOUNT_AUTOFS) {
  89       char *mnt_dir_save = mp_save->mnt->mnt_dir;
  90       mp_save->mnt->mnt_dir = autofs_strdup_space_hack(mnt_dir_save);
  91       error = UNMOUNT_TRAP(mp_save->mnt);
  92       XFREE(mp_save->mnt->mnt_dir);
  93       mp_save->mnt->mnt_dir = mnt_dir_save;
  94     } else
  95 #endif /* NEED_AUTOFS_SPACE_HACK */
  96       error = UNMOUNT_TRAP(mp_save->mnt);
  97     if (error < 0) {
  98       switch ((error = errno)) {
  99       case EINVAL:
 100       case ENOTBLK:
 101         plog(XLOG_WARNING, "unmount: %s is not mounted", mp_save->mnt->mnt_dir);
 102         error = 0;              /* Not really an error */
 103         break;
 104
 105       case ENOENT:
 106         /*
 107          * This could happen if the kernel insists on following symlinks
 108          * when we try to unmount a direct mountpoint. We need to propagate
 109          * the error up so that the top layers know it failed and don't
 110          * try to rmdir() the mountpoint or other silly things.
 111          */
 112         plog(XLOG_ERROR, "mount point %s: %m", mp_save->mnt->mnt_dir);
 113         break;
 114
 115 #if defined(MNT2_GEN_OPT_FORCE) && defined(HAVE_UMOUNT2)
 116       case EBUSY:
 117       case EIO:
 118       case ESTALE:
 119         /* caller determines if forced unmounts should be used */
 120         if (unmount_flags & AMU_UMOUNT_FORCE) {
 121           error = umount2_fs(mntdir, unmount_flags);
 122           if (error < 0)
 123             error = errno;
 124           else
 125             break;              /* all is OK */
 126         }
 127         /* fallthrough */
 128 #endif /* MNT2_GEN_OPT_FORCE && HAVE_UMOUNT2 */
 129       default:
 130         dlog("%s: unmount: %m", mp_save->mnt->mnt_dir);
 131         break;
 132       }
 133     }
 134     dlog("Finished unmount(%s)", mp_save->mnt->mnt_dir);
 135
 136     if (!error) {
 137 #ifdef MOUNT_TABLE_ON_FILE
 138       free_mntlist(mlist);
 139       mp = mlist = read_mtab(mntdir, mnttabname);
 140
 141       /*
 142        * Search the mount table looking for
 143        * the correct (ie last) matching entry
 144        */
 145       mp_save = NULL;
 146       while (mp) {
 147         if (STREQ(mp->mnt->mnt_dir, mntdir))
 148           mp_save = mp;
 149         mp = mp->mnext;
 150       }
 151
 152       if (mp_save) {
 153         mnt_free(mp_save->mnt);
 154         mp_save->mnt = NULL;
 155         rewrite_mtab(mlist, mnttabname);
 156       }
 157 #endif /* MOUNT_TABLE_ON_FILE */
 158     }
 159
 160   } else {
 161
 162     plog(XLOG_ERROR, "Couldn't find how to unmount %s", mntdir);
 163     /*
 164      * Assume it is already unmounted
 165      */
 166     error = 0;
 167   } /* end of "if (mp_save)" statement */
 168
 169   free_mntlist(mlist);
 170
 171   return error;
 172 }
 173
 174
 175 #if defined(MNT2_GEN_OPT_FORCE) && defined(HAVE_UMOUNT2)
 176 /* force unmount, no questions asked, without touching mnttab file */
 177 int
 178 umount2_fs(const char *mntdir, u_int unmount_flags)
 179 {
 180   int error = 0;
 181
 182   if (unmount_flags & AMU_UMOUNT_FORCE) {
 183     plog(XLOG_INFO, "umount2_fs: trying unmount/forced on %s", mntdir);
 184     error = umount2(mntdir, MNT2_GEN_OPT_FORCE); /* Solaris */
 185     if (error < 0 && (errno == EINVAL || errno == ENOENT))
 186       error = 0;                /* ignore EINVAL/ENOENT */
 187     if (error < 0)
 188       plog(XLOG_WARNING, "%s: unmount/force: %m", mntdir);
 189     else
 190       dlog("%s: unmount/force: OK", mntdir);
 191   }
 192   return error;
 193 }
 194 #endif /* MNT2_GEN_OPT_FORCE && HAVE_UMOUNT2 */