/*

 * CDDL HEADER START

 *

 * The contents of this file are subject to the terms of the

 * Common Development and Distribution License, Version 1.0 only

 * (the "License").  You may not use this file except in compliance

 * with the License.

 *

 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE

 * or http://www.opensolaris.org/os/licensing.

 * See the License for the specific language governing permissions

 * and limitations under the License.

 *

 * When distributing Covered Code, include this CDDL HEADER in each

 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.

 * If applicable, add the following below this CDDL HEADER, with the

 * fields enclosed by brackets "[]" replaced with your own identifying

 * information: Portions Copyright [yyyy] [name of copyright owner]

 *

 * CDDL HEADER END

 */

/*

 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.

 * Use is subject to license terms.

 */

#pragma ident	"%Z%%M%	%I%	%E% SMI"

/*

 * Attempt to dynamically link in the ZFS libzfs.so.1 so that we can

 * see if there are any ZFS zpools on any of the slices.

 */

#include <stdlib.h>

#include <stdio.h>

#include <strings.h>

#include <sys/param.h>

#include <sys/errno.h>

#include <sys/types.h>

#include <sys/stat.h>

#include <fcntl.h>

#include <thread.h>

#include <synch.h>

#include <dlfcn.h>

#include <link.h>

#include <ctype.h>

#include "libdiskmgt.h"

#include "disks_private.h"

/*

 * Pointers to libzfs.so functions that we dynamically resolve.

 */

static	int	(*zfsdl_zpool_in_use)(int fd, char **desc, char **name);

static mutex_t			init_lock = DEFAULTMUTEX;

static rwlock_t			zpool_lock = DEFAULTRWLOCK;

static	int			initialized = 0;

static void	*init_zpool();

int

inuse_zpool(char *slice, nvlist_t *attrs, int *errp)

{

	int		found = 0;

	char		*desc, *name;

	int		fd;

	*errp = 0;

	if (slice == NULL) {

	    return (found);

	}

	(void) mutex_lock(&init_lock);

	/*

	 * Dynamically load libzfs

	 */

	if (!initialized) {

		if (!init_zpool()) {

			(void) mutex_unlock(&init_lock);

			return (found);

		}

		initialized = 1;

	}

	(void) mutex_unlock(&init_lock);

	(void) rw_rdlock(&zpool_lock);

	if ((fd = open(slice, O_RDONLY)) > 0) {

		if (zfsdl_zpool_in_use(fd, &desc, &name)) {

			libdiskmgt_add_str(attrs, DM_USED_BY,

				DM_USE_ZPOOL, errp);

			libdiskmgt_add_str(attrs, DM_USED_NAME,

				name, errp);

			found = 1;

		}

	}

	(void) rw_unlock(&zpool_lock);

	return (found);

}

/*

 * Try to dynamically link the zfs functions we need.

 */

static void*

init_zpool()

{

	void	*lh = NULL;

	if ((lh = dlopen("libzfs.so", RTLD_NOW)) == NULL) {

		return (lh);

	}

	/*

	 * Instantiate the functions needed to get zpool configuration

	 * data

	 */

	if ((zfsdl_zpool_in_use = (int (*)(int, char **, char **))dlsym(lh,

	    "zpool_in_use")) == NULL) {

		(void) dlclose(lh);

		return (NULL);

	}

	return (lh);

}