xref: /titanic_41/usr/src/cmd/fs.d/cachefs/umount/umount.c (revision fd9cb95cbb2f626355a60efb9d02c5f0a33c10e6)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * -----------------------------------------------------------------
24  *
25  *			umount.c
26  *
27  * CFS specific umount command.
28  */
29 
30 #pragma ident	"%Z%%M%	%I%	%E% SMI"
31 
32 /*
33  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
34  * Use is subject to license terms.
35  */
36 
37 #include <locale.h>
38 #include <stdio.h>
39 #include <stdlib.h>
40 #include <string.h>
41 #include <stdarg.h>
42 #include <unistd.h>
43 #include <limits.h>
44 #include <errno.h>
45 #include <wait.h>
46 #include <ctype.h>
47 #include <fcntl.h>
48 #include <signal.h>
49 #include <sys/types.h>
50 #include <sys/param.h>
51 #include <sys/stat.h>
52 #include <sys/fcntl.h>
53 #include <sys/mount.h>
54 #include <sys/mntent.h>
55 #include <sys/mnttab.h>
56 #include <sys/fs/cachefs_fs.h>
57 #include <fslib.h>
58 #include <sys/utsname.h>
59 #include <rpc/rpc.h>
60 #include "../common/subr.h"
61 #include "../common/cachefsd.h"
62 
63 /* forward references */
64 void pr_err(char *fmt, ...);
65 void usage(char *msgp);
66 int daemon_unmount(char *mntptp, int);
67 
68 /*
69  *
70  *			main
71  *
72  * Description:
73  *	Main routine for the cfs umount program.
74  * Arguments:
75  *	argc	number of command line arguments
76  *	argv	list of command line arguments
77  * Returns:
78  *	Returns 0 for success or 1 if an error occurs.
79  * Preconditions:
80  */
81 
82 int
83 main(int argc, char **argv)
84 {
85 	char *strp;
86 	int xx;
87 	int ret;
88 	struct mnttab mget;
89 	struct mnttab mref;
90 	FILE *finp;
91 	char mnt_front[PATH_MAX];
92 	char mnt_back[PATH_MAX];
93 	char *p, mnt_frontns[PATH_MAX];
94 	pid_t pid;
95 	int stat_loc;
96 	char *cachedirp, *s;
97 	int ufd, c;
98 	int flag = 0;
99 
100 	(void) setlocale(LC_ALL, "");
101 #if !defined(TEXT_DOMAIN)
102 #define	TEXT_DOMAIN	"SYS_TEST"
103 #endif
104 	(void) textdomain(TEXT_DOMAIN);
105 
106 	/*
107 	 * Set options
108 	 */
109 	while ((c = getopt(argc, argv, "f")) != EOF) {
110 		switch (c) {
111 		case 'f':
112 			flag |= MS_FORCE; /* forced unmount is desired */
113 			break;
114 		default:
115 			usage("Incorrect number of arguments specified");
116 			return (1);
117 		}
118 	}
119 	if (flag & MS_FORCE)
120 		strcpy(mnt_front, argv[2]);
121 	else
122 		strcpy(mnt_front, argv[1]);
123 	mnt_back[0] = '\0';
124 
125 	if (strlen(argv[1]) >= (size_t)PATH_MAX) {
126 		pr_err(gettext("name too long"));
127 		return (1);
128 	}
129 
130 	/*
131 	 * An unmount from autofs may have a
132 	 * space appended to the path.
133 	 * Trim it off before attempting to
134 	 * match the mountpoint in mnttab
135 	 */
136 	strcpy(mnt_frontns, mnt_front);
137 	p = &mnt_frontns[strlen(mnt_frontns) - 1];
138 	if (*p == ' ')
139 		*p = '\0';
140 
141 	/* get the mount point and the back file system mount point */
142 	finp = fopen(MNTTAB, "r");
143 	if (finp) {
144 		mntnull(&mref);
145 		mref.mnt_mountp = mnt_frontns;
146 		mref.mnt_fstype = "cachefs";
147 		ret = getmntany(finp, &mget, &mref);
148 
149 		cachedirp = (char *)malloc(strlen(mget.mnt_special) + 1);
150 		strcpy(cachedirp, mget.mnt_special);
151 		/*
152 		 * AutoClient mounts do not have .cfs_mnt_points string in
153 		 * them, so strstr would return NULL. So .cfs_unmnt file
154 		 * is not updated.
155 		 */
156 		if ((s = strstr(cachedirp, ".cfs_mnt_points")) != NULL) {
157 			time32_t btime;
158 
159 			xx = -1;
160 			cachedirp[s-cachedirp] = '\0';
161 			strcat(cachedirp, CACHEFS_UNMNT_FILE);
162 			if ((ufd = open(cachedirp, O_WRONLY|O_CREAT|O_TRUNC,
163 					0600)) > 0) {
164 				if ((btime = get_boottime()) != -1)
165 				    xx = write(ufd, &btime, sizeof (time32_t));
166 				close(ufd);
167 			}
168 			if (xx < 0)
169 				pr_err(gettext(".cfs_unmnt error"));
170 		}
171 
172 		if (ret != -1) {
173 			if (mget.mnt_special)
174 				strcpy(mnt_back, mget.mnt_special);
175 		} else {
176 			mref.mnt_special = mref.mnt_mountp;
177 			mref.mnt_mountp = NULL;
178 			rewind(finp);
179 			ret = getmntany(finp, &mget, &mref);
180 			if (ret != -1) {
181 				strcpy(mnt_front, mget.mnt_mountp);
182 				if (mget.mnt_special)
183 					strcpy(mnt_back, mget.mnt_special);
184 			} else {
185 				pr_err(gettext("warning: %s not in mnttab"),
186 				    mref.mnt_special);
187 			}
188 		}
189 		fclose(finp);
190 	}
191 
192 	/* try to get the daemon to unmount this file system for us */
193 	xx = daemon_unmount(mnt_front, flag);
194 	if (xx == ENOTSUP)
195 		return (1);
196 	if (xx == EBUSY) {
197 		pr_err(gettext("%s %s"), mnt_front, strerror(xx));
198 		return (1);
199 	}
200 	if (xx == EIO) {
201 		/* try to unmount the file system directly */
202 		if (umount2(mnt_front, flag) == -1) {
203 			pr_err(gettext("%s %s"), mnt_front, strerror(errno));
204 			return (1);
205 		}
206 	}
207 
208 	/* if we do not know the name of the back file system mount point */
209 	if (mnt_back[0] == '\0') {
210 		/* all done */
211 		return (0);
212 	}
213 
214 	/*
215 	 * If the back file system was mounted on a directory with a
216 	 * parent name of BACKMNT_NAME then we assume that we
217 	 * mounted it and that it is okay to try to umount it.
218 	 */
219 	if (strstr(mnt_back, BACKMNT_NAME) == NULL)
220 		return (0);
221 
222 	/* if no back file system mounted */
223 	if (strcmp(mnt_back, "nobackfs") == 0)
224 		return (0);
225 
226 	/* fork */
227 	if ((pid = fork()) == -1) {
228 		pr_err(gettext("could not fork %s"), strerror(errno));
229 		return (1);
230 	}
231 
232 	/* if the child */
233 	if (pid == 0) {
234 		/* invoke the umount command on the back file system */
235 		xx = execl("/sbin/umount", "/sbin/umount", mnt_back, NULL);
236 		pr_err(gettext("could not exec /sbin/umount"
237 		    " on back file system %s"), strerror(errno));
238 	}
239 
240 	/* else if the parent */
241 	else {
242 		/* wait for the child to exit */
243 		if (wait(&stat_loc) == -1) {
244 			pr_err(gettext("wait failed %s"), strerror(errno));
245 			return (1);
246 		}
247 
248 		if (!WIFEXITED(stat_loc)) {
249 			pr_err(gettext("back umount did not exit"));
250 			return (1);
251 		}
252 
253 		xx = WEXITSTATUS(stat_loc);
254 		if (xx) {
255 			pr_err(gettext("back umount failed"));
256 			return (xx);
257 		}
258 	}
259 
260 	/* delete the back file system mount point since we created it */
261 	rmdir(mnt_back);
262 
263 	return (xx);
264 }
265 
266 /*
267  *
268  *			pr_err
269  *
270  * Description:
271  *	Prints an error message to stderr.
272  * Arguments:
273  *	fmt	printf style format
274  *	...	arguments for fmt
275  * Returns:
276  * Preconditions:
277  *	precond(fmt)
278  */
279 
280 void
281 pr_err(char *fmt, ...)
282 {
283 	va_list ap;
284 
285 	va_start(ap, fmt);
286 	(void) fprintf(stderr, gettext("umount -F cachefs: "));
287 	(void) vfprintf(stderr, fmt, ap);
288 	(void) fprintf(stderr, "\n");
289 	va_end(ap);
290 }
291 
292 /*
293  *
294  *			usage
295  *
296  * Description:
297  *	Prints a usage message.
298  * Arguments:
299  *	An optional additional message to be displayed.
300  * Returns:
301  * Preconditions:
302  */
303 
304 void
305 usage(char *msgp)
306 {
307 	if (msgp)
308 		pr_err(gettext("%s"), msgp);
309 	fprintf(stderr, gettext("Usage: umount -F cachefs dir"));
310 }
311 
312 /*
313  *
314  *			daemon_unmount
315  *
316  * Description:
317  *	Notifies the cachefsd of an unmount request.
318  * Arguments:
319  *	Mount point to unmount.
320  * Returns:
321  *	Returns 0 if the cachefsd unmounted the file system
322  *		EIO if should try unmount directly
323  *		EBUSY if did not unmount because busy
324  *		EAGAIN if umounted but should not unmount nfs mount
325  *
326  * Preconditions:
327  *	precond(mntptp)
328  */
329 
330 int
331 daemon_unmount(char *mntptp, int flag)
332 {
333 	CLIENT *clnt;
334 	enum clnt_stat retval;
335 	int xx;
336 	int result;
337 	char *hostp;
338 	struct utsname info;
339 	static struct timeval TIMEOUT = { 60*60, 0 };
340 	static struct timeval create_timeout = { 5, 0};
341 	struct cachefsd_fs_unmounted uargs;
342 
343 	/* get the host name */
344 	xx = uname(&info);
345 	if (xx == -1) {
346 		pr_err(gettext("cannot get host name, errno %d"), errno);
347 		return (EIO);
348 	}
349 	hostp = info.nodename;
350 	uargs.mntpt = mntptp;
351 	uargs.flag = flag;
352 
353 	/* creat the connection to the daemon */
354 	clnt = clnt_create_timed(hostp, CACHEFSDPROG, CACHEFSDVERS, "local",
355 	    &create_timeout);
356 	if (clnt == NULL) {
357 		pr_err(gettext("cachefsd is not running"));
358 		return (EIO);
359 	}
360 	clnt_control(clnt, CLSET_TIMEOUT, (char *)&TIMEOUT);
361 
362 	retval = cachefsd_fs_unmounted_1(&uargs, &result, clnt);
363 	if (retval != RPC_SUCCESS) {
364 		clnt_perror(clnt, gettext("cachefsd is not responding"));
365 		clnt_destroy(clnt);
366 		return (EIO);
367 	}
368 
369 	clnt_destroy(clnt);
370 
371 	return (result);
372 }
373