1 /*
2 * Copyright (c) 1989 Jan-Simon Pendry
3 * Copyright (c) 1989 Imperial College of Science, Technology & Medicine
4 * Copyright (c) 1989, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Jan-Simon Pendry at Imperial College, London.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 * from: @(#)ifs_ops.c 8.1 (Berkeley) 6/6/93
35 * $Id: ifs_ops.c,v 1.7 2022/12/28 21:30:15 jmc Exp $
36 */
37
38 #include "am.h"
39
40 #ifdef HAS_IFS
41
42 /*
43 * Inheritance file system.
44 * This implements a filesystem restart.
45 *
46 * This is a *gross* hack - it knows far too
47 * much about the way other parts of the
48 * system work. See restart.c too.
49 */
50 static char not_a_filesystem[] = "Attempting to inherit not-a-filesystem";
51 /*
52 * This should never be called.
53 */
54 static char *
ifs_match(am_opts * fo)55 ifs_match(am_opts *fo)
56 {
57 plog(XLOG_FATAL, "ifs_match called!");
58 return 0;
59 }
60
61 static int
ifs_init(mntfs * mf)62 ifs_init(mntfs *mf)
63 {
64 mntfs *mf_link = (mntfs *) mf->mf_private;
65 if (mf_link == 0) {
66 plog(XLOG_FATAL, "%s", not_a_filesystem);
67 return EINVAL;
68 }
69 #ifdef notdef
70 /*
71 * Fill in attribute fields
72 */
73 mf_link->mf_fattr.type = NFLNK;
74 mf_link->mf_fattr.mode = NFSMODE_LNK | 0777;
75 mf_link->mf_fattr.nlink = 1;
76 mf_link->mf_fattr.size = MAXPATHLEN / 4;
77 #endif
78 if (mf_link->mf_ops->fs_init)
79 return (*mf_link->mf_ops->fs_init)(mf_link);
80 return 0;
81 }
82
83 static mntfs *
ifs_inherit(mntfs * mf)84 ifs_inherit(mntfs *mf)
85 {
86 /*
87 * Take the linked mount point and
88 * propagate.
89 */
90 mntfs *mf_link = (mntfs *) mf->mf_private;
91 if (mf_link == 0) {
92 plog(XLOG_FATAL, "%s", not_a_filesystem);
93 return 0; /*XXX*/
94 }
95
96 mf_link->mf_fo = mf->mf_fo;
97 #ifdef notdef
98 mf_link->mf_fattr.fileid = mf->mf_fattr.fileid;
99 #endif /* notdef */
100
101 /*
102 * Discard the old map.
103 * Don't call am_unmounted since this
104 * node was never really mounted in the
105 * first place.
106 */
107 mf->mf_private = 0;
108 free_mntfs(mf);
109 /*
110 * Free the dangling reference
111 * to the mount link.
112 */
113 free_mntfs(mf_link);
114 /*
115 * Get a hold of the other entry
116 */
117 mf_link->mf_flags &= ~MFF_RESTART;
118
119 /* Say what happened */
120 plog(XLOG_INFO, "restarting %s on %s", mf_link->mf_info, mf_link->mf_mount);
121
122 return mf_link;
123 }
124
125 static int
ifs_mount(am_node * mp)126 ifs_mount(am_node *mp)
127 {
128 mntfs *newmf = ifs_inherit(mp->am_mnt);
129 if (newmf) {
130 mp->am_mnt = newmf;
131 /*
132 * XXX - must do the am_mounted call here
133 */
134 if (newmf->mf_ops->fs_flags & FS_MBACKGROUND)
135 am_mounted(mp);
136
137 new_ttl(mp);
138 return 0;
139 }
140 return EINVAL;
141 }
142
143 static int
ifs_fmount(mntfs * mf)144 ifs_fmount(mntfs *mf)
145 {
146 am_node *mp = find_mf(mf);
147 if (mp)
148 return ifs_mount(mp);
149 return ifs_inherit(mf) ? 0 : EINVAL;
150 }
151
152 static int
ifs_fumount(mntfs * mf)153 ifs_fumount(mntfs *mf)
154 {
155 /*
156 * Always succeed
157 */
158 return 0;
159 }
160
161 /*
162 * Ops structure
163 */
164 am_ops ifs_ops = {
165 "inherit",
166 ifs_match,
167 ifs_init,
168 ifs_mount,
169 ifs_fmount,
170 auto_fumount,
171 ifs_fumount,
172 efs_lookuppn,
173 efs_readdir,
174 0, /* ifs_readlink */
175 0, /* ifs_mounted */
176 0, /* ifs_umounted */
177 find_afs_srvr,
178 FS_DISCARD
179 };
180
181 #endif /* HAS_IFS */
182