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1 /*
2 * Copyright (c) 1997-2005 Erez Zadok
3 * Copyright (c) 1990 Jan-Simon Pendry
4 * Copyright (c) 1990 Imperial College of Science, Technology & Medicine
5 * Copyright (c) 1990 The Regents of the University of California.
6 * All rights reserved.
7 *
8 * This code is derived from software contributed to Berkeley by
9 * Jan-Simon Pendry at Imperial College, London.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. All advertising materials mentioning features or use of this software
20 * must display the following acknowledgment:
21 * This product includes software developed by the University of
22 * California, Berkeley and its contributors.
23 * 4. Neither the name of the University nor the names of its contributors
24 * may be used to endorse or promote products derived from this software
25 * without specific prior written permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37 * SUCH DAMAGE.
38 *
39 *
40 * File: am-utils/amd/amfs_toplvl.c
41 *
42 */
43
44 /*
45 * Top-level file system
46 */
47
48 #ifdef HAVE_CONFIG_H
49 # include <config.h>
50 #endif /* HAVE_CONFIG_H */
51 #include <am_defs.h>
52 #include <amd.h>
53
54 /****************************************************************************
55 *** FORWARD DEFINITIONS ***
56 ****************************************************************************/
57 static int amfs_toplvl_init(mntfs *mf);
58
59 /****************************************************************************
60 *** OPS STRUCTURES ***
61 ****************************************************************************/
62 am_ops amfs_toplvl_ops =
63 {
64 "toplvl",
65 amfs_generic_match,
66 amfs_toplvl_init, /* amfs_toplvl_init */
67 amfs_toplvl_mount,
68 amfs_toplvl_umount,
69 amfs_generic_lookup_child,
70 amfs_generic_mount_child,
71 amfs_generic_readdir,
72 0, /* amfs_toplvl_readlink */
73 amfs_generic_mounted,
74 0, /* amfs_toplvl_umounted */
75 amfs_generic_find_srvr,
76 0, /* amfs_toplvl_get_wchan */
77 FS_MKMNT | FS_NOTIMEOUT | FS_BACKGROUND |
78 FS_AMQINFO | FS_DIRECTORY, /* nfs_fs_flags */
79 #ifdef HAVE_FS_AUTOFS
80 AUTOFS_TOPLVL_FS_FLAGS,
81 #endif /* HAVE_FS_AUTOFS */
82 };
83
84
85 /****************************************************************************
86 *** FUNCTIONS ***
87 ****************************************************************************/
88
89 static void
90 set_auto_attrcache_timeout(char *preopts, char *opts)
91 {
92
93 #ifdef MNTTAB_OPT_NOAC
94 /*
95 * Don't cache attributes - they are changing under the kernel's feet.
96 * For example, IRIX5.2 will dispense with nfs lookup calls and hand stale
97 * filehandles to getattr unless we disable attribute caching on the
98 * automount points.
99 */
100 if (gopt.auto_attrcache == 0) {
101 sprintf(preopts, ",%s", MNTTAB_OPT_NOAC);
102 strcat(opts, preopts);
103 }
104 #endif /* MNTTAB_OPT_NOAC */
105
106 /*
107 * XXX: note that setting these to 0 in the past resulted in an error on
108 * some systems, which is why it's better to use "noac" if possible. For
109 * now, we're setting everything possible, but if this will cause trouble,
110 * then we'll have to condition the remainder of this on OPT_NOAC.
111 */
112 #ifdef MNTTAB_OPT_ACTIMEO
113 sprintf(preopts, ",%s=%d", MNTTAB_OPT_ACTIMEO, gopt.auto_attrcache);
114 strcat(opts, preopts);
115 #else /* MNTTAB_OPT_ACTIMEO */
116 # ifdef MNTTAB_OPT_ACDIRMIN
117 sprintf(preopts, ",%s=%d", MNTTAB_OPT_ACTDIRMIN, gopt.auto_attrcache);
118 strcat(opts, preopts);
119 # endif /* MNTTAB_OPT_ACDIRMIN */
120 # ifdef MNTTAB_OPT_ACDIRMAX
121 sprintf(preopts, ",%s=%d", MNTTAB_OPT_ACTDIRMAX, gopt.auto_attrcache);
122 strcat(opts, preopts);
123 # endif /* MNTTAB_OPT_ACDIRMAX */
124 # ifdef MNTTAB_OPT_ACREGMIN
125 sprintf(preopts, ",%s=%d", MNTTAB_OPT_ACTREGMIN, gopt.auto_attrcache);
126 strcat(opts, preopts);
127 # endif /* MNTTAB_OPT_ACREGMIN */
128 # ifdef MNTTAB_OPT_ACREGMAX
129 sprintf(preopts, ",%s=%d", MNTTAB_OPT_ACTREGMAX, gopt.auto_attrcache);
130 strcat(opts, preopts);
131 # endif /* MNTTAB_OPT_ACREGMAX */
132 #endif /* MNTTAB_OPT_ACTIMEO */
133 }
134
135
136 /*
137 * Initialize a top-level mount. In our case, if the user asked for
138 * forced_unmounts, and the OS supports it, then we try forced/lazy unmounts
139 * on any previous toplvl mounts. This is useful if a previous Amd died and
140 * left behind toplvl mount points (this Amd will clean them up).
141 *
142 * WARNING: Don't use forced/lazy unmounts if you have another valid Amd
143 * running, because this code WILL force those valid toplvl mount points to
144 * be detached as well!
145 */
146 static int
147 amfs_toplvl_init(mntfs *mf)
148 {
149 int error = 0;
150
151 #if defined(MNT2_GEN_OPT_FORCE) || defined(MNT2_GEN_OPT_DETACH)
152 if (gopt.flags & CFM_FORCED_UNMOUNTS) {
153 plog(XLOG_INFO, "amfs_toplvl_init: trying forced/lazy unmount of %s",
154 mf->mf_mount);
155 error = umount2_fs(mf->mf_mount, AMU_UMOUNT_FORCE | AMU_UMOUNT_DETACH);
156 if (error)
157 plog(XLOG_INFO, "amfs_toplvl_init: forced/lazy unmount failed: %m");
158 else
159 dlog("amfs_toplvl_init: forced/lazy unmount succeeded");
160 }
161 #endif /* MNT2_GEN_OPT_FORCE || MNT2_GEN_OPT_DETACH */
162 return error;
163 }
164
165
166 /*
167 * Mount the top-level
168 */
169 int
170 amfs_toplvl_mount(am_node *mp, mntfs *mf)
171 {
172 struct stat stb;
173 char opts[256], preopts[256];
174 int error;
175
176 /*
177 * Mounting the automounter.
178 * Make sure the mount directory exists, construct
179 * the mount options and call the mount_amfs_toplvl routine.
180 */
181
182 if (stat(mp->am_path, &stb) < 0) {
183 return errno;
184 } else if ((stb.st_mode & S_IFMT) != S_IFDIR) {
185 plog(XLOG_WARNING, "%s is not a directory", mp->am_path);
186 return ENOTDIR;
187 }
188
189 /*
190 * Construct some mount options:
191 *
192 * Tack on magic map=<mapname> option in mtab to emulate
193 * SunOS automounter behavior.
194 */
195
196 #ifdef HAVE_FS_AUTOFS
197 if (mf->mf_flags & MFF_IS_AUTOFS) {
198 autofs_get_opts(opts, mp->am_autofs_fh);
199 } else
200 #endif /* HAVE_FS_AUTOFS */
201 {
202 preopts[0] = '\0';
203 #ifdef MNTTAB_OPT_INTR
204 strcat(preopts, MNTTAB_OPT_INTR);
205 strcat(preopts, ",");
206 #endif /* MNTTAB_OPT_INTR */
207 #ifdef MNTTAB_OPT_IGNORE
208 strcat(preopts, MNTTAB_OPT_IGNORE);
209 strcat(preopts, ",");
210 #endif /* MNTTAB_OPT_IGNORE */
211 #ifdef WANT_TIMEO_AND_RETRANS_ON_TOPLVL
212 sprintf(opts, "%s%s,%s=%d,%s=%d,%s=%d,%s,map=%s",
213 #else /* WANT_TIMEO_AND_RETRANS_ON_TOPLVL */
214 sprintf(opts, "%s%s,%s=%d,%s,map=%s",
215 #endif /* WANT_TIMEO_AND_RETRANS_ON_TOPLVL */
216 preopts,
217 MNTTAB_OPT_RW,
218 MNTTAB_OPT_PORT, nfs_port,
219 #ifdef WANT_TIMEO_AND_RETRANS_ON_TOPLVL
220 /* note: TIMEO+RETRANS for toplvl are only "udp" currently */
221 MNTTAB_OPT_TIMEO, gopt.amfs_auto_timeo[AMU_TYPE_UDP],
222 MNTTAB_OPT_RETRANS, gopt.amfs_auto_retrans[AMU_TYPE_UDP],
223 #endif /* WANT_TIMEO_AND_RETRANS_ON_TOPLVL */
224 mf->mf_ops->fs_type, mf->mf_info);
225 #ifdef MNTTAB_OPT_NOAC
226 if (gopt.auto_attrcache == 0) {
227 strcat(opts, ",");
228 strcat(opts, MNTTAB_OPT_NOAC);
229 } else
230 #endif /* MNTTAB_OPT_NOAC */
231 set_auto_attrcache_timeout(preopts, opts);
232 }
233
234 /* now do the mount */
235 error = amfs_mount(mp, mf, opts);
236 if (error) {
237 errno = error;
238 plog(XLOG_FATAL, "amfs_toplvl_mount: amfs_mount failed: %m");
239 return error;
240 }
241 return 0;
242 }
243
244
245 /*
246 * Unmount a top-level automount node
247 */
248 int
249 amfs_toplvl_umount(am_node *mp, mntfs *mf)
250 {
251 struct stat stb;
252 int unmount_flags = (mf->mf_flags & MFF_ON_AUTOFS) ? AMU_UMOUNT_AUTOFS : 0;
253 int error;
254 int count = 0; /* how many times did we try to unmount? */
255
256 again:
257 /*
258 * The lstat is needed if this mount is type=direct.
259 * When that happens, the kernel cache gets confused
260 * between the underlying type (dir) and the mounted
261 * type (link) and so needs to be re-synced before
262 * the unmount. This is all because the unmount system
263 * call follows links and so can't actually unmount
264 * a link (stupid!). It was noted that doing an ls -ld
265 * of the mount point to see why things were not working
266 * actually fixed the problem - so simulate an ls -ld here.
267 */
268 if (lstat(mp->am_path, &stb) < 0) {
269 error = errno;
270 dlog("lstat(%s): %m", mp->am_path);
271 goto out;
272 }
273 if ((stb.st_mode & S_IFMT) != S_IFDIR) {
274 plog(XLOG_ERROR, "amfs_toplvl_umount: %s is not a directory, aborting.", mp->am_path);
275 error = ENOTDIR;
276 goto out;
277 }
278
279 error = UMOUNT_FS(mp->am_path, mnttab_file_name, unmount_flags);
280 if (error == EBUSY) {
281 #ifdef HAVE_FS_AUTOFS
282 /*
283 * autofs mounts are "in place", so it is possible
284 * that we can't just unmount our mount points and go away.
285 * If that's the case, just give up.
286 */
287 if (mf->mf_flags & MFF_IS_AUTOFS)
288 return error;
289 #endif /* HAVE_FS_AUTOFS */
290 plog(XLOG_WARNING, "amfs_toplvl_unmount retrying %s in 1s", mp->am_path);
291 count++;
292 sleep(1);
293 /*
294 * If user wants forced/lazy unmount semantics, then set those flags,
295 * but only after we've tried normal lstat/umount a few times --
296 * otherwise forced unmounts may hang this very same Amd (by preventing
297 * it from achieving a clean unmount).
298 */
299 if (gopt.flags & CFM_FORCED_UNMOUNTS) {
300 if (count == 5) { /* after 5 seconds, try MNT_FORCE */
301 dlog("enabling forced unmounts for toplvl node %s", mp->am_path);
302 unmount_flags |= AMU_UMOUNT_FORCE;
303 }
304 if (count == 10) { /* after 10 seconds, try MNT_DETACH */
305 dlog("enabling detached unmounts for toplvl node %s", mp->am_path);
306 unmount_flags |= AMU_UMOUNT_DETACH;
307 }
308 }
309 goto again;
310 }
311 out:
312 return error;
313 }
314
