NetBSD/sbin/mount_lfs/mount_lfs.c

/*	$NetBSD: mount_lfs.c,v 1.21 2005/01/31 05:19:19 erh Exp $	*/

/*-
 * Copyright (c) 1993, 1994
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/cdefs.h>
#ifndef lint
__COPYRIGHT("@(#) Copyright (c) 1993, 1994\n\
	The Regents of the University of California.  All rights reserved.\n");
#endif /* not lint */

#ifndef lint
#if 0
static char sccsid[] = "@(#)mount_lfs.c	8.4 (Berkeley) 4/26/95";
#else
__RCSID("$NetBSD: mount_lfs.c,v 1.21 2005/01/31 05:19:19 erh Exp $");
#endif
#endif /* not lint */

#include <sys/param.h>
#include <sys/mount.h>

#include <ufs/ufs/ufsmount.h>

#include <err.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <paths.h>

#include <signal.h>

#include <mntopts.h>
#include "pathnames.h"

static const struct mntopt mopts[] = {
	MOPT_STDOPTS,
	MOPT_UPDATE,
	MOPT_GETARGS,
	MOPT_NOATIME,
	{ NULL }
};

int		main __P((int, char *[]));
int		mount_lfs __P((int, char *[]));
static void	invoke_cleaner __P((char *));
static void	usage __P((void));
static void	kill_daemon __P((char *));
static void	kill_cleaner __P((char *));

static int short_rds, cleaner_debug, cleaner_bytes;
static char *nsegs;

#ifndef MOUNT_NOMAIN
int
main(argc, argv)
	int argc;
	char **argv;
{
	return mount_lfs(argc, argv);
}
#endif

int
mount_lfs(argc, argv)
	int argc;
	char *argv[];
{
	struct ufs_args args;
	int ch, mntflags, noclean, mntsize, oldflags, i;
	char fs_name[MAXPATHLEN], canon_dev[MAXPATHLEN];
	char *options;

	const char *errcause;
	struct statvfs *mntbuf;

	options = NULL;
	nsegs = "4";
	mntflags = noclean = 0;
	cleaner_bytes = 1;
	while ((ch = getopt(argc, argv, "bdN:no:s")) != -1)
		switch (ch) {
		case 'b':
			cleaner_bytes = !cleaner_bytes;
			break;
		case 'd':
			cleaner_debug = 1;
			break;
		case 'n':
			noclean = 1;
			break;
		case 'N':
			nsegs = optarg;
			break;
		case 'o':
			getmntopts(optarg, mopts, &mntflags, 0);
			break;
		case 's':
			short_rds = 1;
			break;
		case '?':
		default:
			usage();
		}
	argc -= optind;
	argv += optind;

	if (argc != 2)
		usage();

	if (realpath(argv[0], canon_dev) == NULL)     /* Check device path */
		err(1, "realpath %s", argv[0]);
	if (strncmp(argv[0], canon_dev, MAXPATHLEN)) {
		warnx("\"%s\" is a relative path.", argv[0]);
		warnx("using \"%s\" instead.", canon_dev);
	}
	args.fspec = canon_dev;

	if (realpath(argv[1], fs_name) == NULL)      /* Check mounton path */
		err(1, "realpath %s", argv[1]);
	if (strncmp(argv[1], fs_name, MAXPATHLEN)) {
		warnx("\"%s\" is a relative path.", argv[1]);
		warnx("using \"%s\" instead.", fs_name);
	}

#define DEFAULT_ROOTUID	-2
	args.export.ex_root = DEFAULT_ROOTUID;
	if (mntflags & MNT_RDONLY) {
		args.export.ex_flags = MNT_EXRDONLY;
		noclean = 1;
	} else
		args.export.ex_flags = 0;

	/*
	 * Record the previous status of this filesystem (if any) before
	 * performing the mount, so we can know whether to start or
	 * kill the cleaner process below.
	 */
	oldflags = MNT_RDONLY; /* If not mounted, pretend r/o */
	if (mntflags & MNT_UPDATE) {
		if ((mntsize = getmntinfo(&mntbuf, MNT_NOWAIT)) == 0)
			err(1, "getmntinfo");
		for (i = 0; i < mntsize; i++) {
			if (strcmp(mntbuf[i].f_mntfromname, args.fspec) == 0) {
				oldflags = mntbuf[i].f_flag;
				break;
			}
		}
	}

	if (mount(MOUNT_LFS, fs_name, mntflags, &args)) {
		switch (errno) {
		case EMFILE:
			errcause = "mount table full";
			break;
		case EINVAL:
			if (mntflags & MNT_UPDATE)
				errcause =
			    "specified device does not match mounted device";
			else
				errcause = "incorrect super block";
			break;
		default:
			errcause = strerror(errno);
			break;
		}
		errx(1, "%s on %s: %s", args.fspec, fs_name, errcause);
	}

	/* Not mounting fresh or upgrading to r/w; don't start the cleaner */
	if (!(oldflags & MNT_RDONLY) || (mntflags & MNT_RDONLY))
		noclean = 1;
	if (!noclean)
		invoke_cleaner(fs_name);
		/* NOTREACHED */

	/* Downgrade to r/o; kill the cleaner */
	if ((mntflags & MNT_RDONLY) && !(oldflags & MNT_RDONLY))
		kill_cleaner(fs_name);

	exit(0);
}

static void
kill_daemon(pidname)
	char *pidname;
{
	FILE *fp;
	char s[80];
	pid_t pid;

	fp = fopen(pidname, "r");
	if (fp) {
		fgets(s, 80, fp);
		pid = atoi(s);
		if (pid)
			kill(pid, SIGINT);
		fclose(fp);
	}
}

static void
kill_cleaner(name)
	char *name;
{
	char *pidname;
	char *cp;
	int off;

	/* Parent first */
	asprintf(&pidname, "%slfs_cleanerd:m:%s.pid", _PATH_VARRUN, name);
	if (!pidname)
		err(1, "malloc");
	off = strlen(_PATH_VARRUN);
	while((cp = strchr(pidname + off, '/')) != NULL)
		*cp = '|';
	kill_daemon(pidname);
	free(pidname);

	/* Then child */
	asprintf(&pidname, "%slfs_cleanerd:s:%s.pid", _PATH_VARRUN, name);
	if (!pidname)
		err(1, "malloc");
	off = strlen(_PATH_VARRUN);
	while((cp = strchr(pidname + off, '/')) != NULL)
		*cp = '|';
	kill_daemon(pidname);
	free(pidname);
}

static void
invoke_cleaner(name)
	char *name;
{
	char *args[6], **ap = args;

	/* Build the argument list. */
	*ap++ = _PATH_LFS_CLEANERD;
	if (cleaner_bytes)
		*ap++ = "-b";
	if (nsegs) {
		*ap++ = "-n";
		*ap++ = nsegs;
	}
	if (short_rds)
		*ap++ = "-s";
	if (cleaner_debug)
		*ap++ = "-d";
	*ap++ = name;
	*ap = NULL;

	execv(args[0], args);
	err(1, "exec %s", _PATH_LFS_CLEANERD);
}

static void
usage()
{
	(void)fprintf(stderr,
		"usage: %s [-bdns] [-N nsegs] [-o options] special node\n",
		getprogname());
	exit(1);
}