1 /*	$NetBSD: umount_default.c,v 1.1.1.2 2009/03/20 20:26:52 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/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 */
195