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 (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21/*
22 * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
23 * Use is subject to license terms.
24 */
25
26#pragma ident	"%Z%%M%	%I%	%E% SMI"
27
28/*
29 * Attempt to dynamically link in the ZFS libzfs.so.1 so that we can
30 * see if there are any ZFS zpools on any of the slices.
31 */
32
33#include <stdlib.h>
34#include <stdio.h>
35#include <strings.h>
36#include <unistd.h>
37#include <sys/param.h>
38#include <sys/errno.h>
39#include <sys/types.h>
40#include <sys/stat.h>
41#include <fcntl.h>
42#include <thread.h>
43#include <synch.h>
44#include <dlfcn.h>
45#include <link.h>
46#include <ctype.h>
47#include <sys/fs/zfs.h>
48
49#include <libzfs.h>
50#include "libdiskmgt.h"
51#include "disks_private.h"
52
53/*
54 * Pointers to libzfs.so functions that we dynamically resolve.
55 */
56static int (*zfsdl_zpool_in_use)(libzfs_handle_t *hdl, int fd,
57    pool_state_t *state, char **name, boolean_t *);
58static libzfs_handle_t *(*zfsdl_libzfs_init)(boolean_t);
59
60static mutex_t			init_lock = DEFAULTMUTEX;
61static rwlock_t			zpool_lock = DEFAULTRWLOCK;
62static boolean_t		initialized;
63static libzfs_handle_t		*zfs_hdl;
64
65static void	*init_zpool();
66
67static int
68inuse_zpool_common(char *slice, nvlist_t *attrs, int *errp, char *type)
69{
70	int		found = 0;
71	char		*name;
72	int		fd;
73	pool_state_t	state;
74	boolean_t	used;
75
76	*errp = 0;
77	if (slice == NULL) {
78	    return (found);
79	}
80
81	(void) mutex_lock(&init_lock);
82
83	/*
84	 * Dynamically load libzfs
85	 */
86	if (!initialized) {
87		if (!init_zpool()) {
88			(void) mutex_unlock(&init_lock);
89			return (found);
90		}
91		initialized = B_TRUE;
92	}
93	(void) mutex_unlock(&init_lock);
94	(void) rw_rdlock(&zpool_lock);
95	if ((fd = open(slice, O_RDONLY)) > 0) {
96		name = NULL;
97		if (zfsdl_zpool_in_use(zfs_hdl, fd, &state,
98		    &name, &used) == 0 && used) {
99			if (strcmp(type, DM_USE_ACTIVE_ZPOOL) == 0) {
100				if (state == POOL_STATE_ACTIVE) {
101					found = 1;
102				} else if (state == POOL_STATE_SPARE) {
103					found = 1;
104					type = DM_USE_SPARE_ZPOOL;
105				} else if (state == POOL_STATE_L2CACHE) {
106					found = 1;
107					type = DM_USE_L2CACHE_ZPOOL;
108				}
109			} else {
110				found = 1;
111			}
112
113			if (found) {
114				libdiskmgt_add_str(attrs, DM_USED_BY,
115				    type, errp);
116				libdiskmgt_add_str(attrs, DM_USED_NAME,
117				    name, errp);
118			}
119		}
120		if (name)
121			free(name);
122		(void) close(fd);
123	}
124	(void) rw_unlock(&zpool_lock);
125
126	return (found);
127}
128
129int
130inuse_active_zpool(char *slice, nvlist_t *attrs, int *errp)
131{
132	return (inuse_zpool_common(slice, attrs, errp, DM_USE_ACTIVE_ZPOOL));
133}
134
135int
136inuse_exported_zpool(char *slice, nvlist_t *attrs, int *errp)
137{
138	return (inuse_zpool_common(slice, attrs, errp, DM_USE_EXPORTED_ZPOOL));
139}
140
141/*
142 * Try to dynamically link the zfs functions we need.
143 */
144static void*
145init_zpool()
146{
147	void	*lh = NULL;
148
149	if ((lh = dlopen("libzfs.so", RTLD_NOW)) == NULL) {
150		return (lh);
151	}
152
153	/*
154	 * Instantiate the functions needed to get zpool configuration
155	 * data
156	 */
157	if ((zfsdl_libzfs_init = (libzfs_handle_t *(*)(boolean_t))
158	    dlsym(lh, "libzfs_init")) == NULL ||
159	    (zfsdl_zpool_in_use = (int (*)(libzfs_handle_t *, int,
160	    pool_state_t *, char **, boolean_t *))
161	    dlsym(lh, "zpool_in_use")) == NULL) {
162		(void) dlclose(lh);
163		return (NULL);
164	}
165
166	if ((zfs_hdl = (*zfsdl_libzfs_init)(B_FALSE)) == NULL) {
167		(void) dlclose(lh);
168		return (NULL);
169	}
170
171	return (lh);
172}
173