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 (c) 2006, 2010, Oracle and/or its affiliates. All rights reserved.
23 */
24
25 /*
26 * FMD Topology Handling
27 *
28 * Fault manager scheme and module plug-ins may need access to the latest
29 * libtopo snapshot. Upon fmd initialization, a snapshot is taken and
30 * made available via fmd_fmri_topology() and fmd_hdl_topology(). Each
31 * of these routines returns a libtopo snapshot handle back to the caller.
32 * New snapshots are taken if and when a DR event causes the DR generation
33 * number to increase. The current snapshot is retained to assure consistency
34 * for modules still using older snapshots and the latest snapshot handle is
35 * returned to the caller.
36 */
37
38 #include <fmd_alloc.h>
39 #include <fmd_error.h>
40 #include <fmd_subr.h>
41 #include <fmd_topo.h>
42 #include <fmd.h>
43
44 #include <string.h>
45 #include <unistd.h>
46 #include <sys/types.h>
47 #include <fm/fmd_fmri.h>
48 #include <fm/libtopo.h>
49
50 static void
fmd_topo_rele_locked(fmd_topo_t * ftp)51 fmd_topo_rele_locked(fmd_topo_t *ftp)
52 {
53 ASSERT(MUTEX_HELD(&fmd.d_topo_lock));
54
55 if (--ftp->ft_refcount == 0) {
56 fmd_list_delete(&fmd.d_topo_list, ftp);
57 topo_close(ftp->ft_hdl);
58 fmd_free(ftp, sizeof (fmd_topo_t));
59 }
60 }
61
62 void
fmd_topo_update(void)63 fmd_topo_update(void)
64 {
65 int err;
66 topo_hdl_t *tp;
67 fmd_topo_t *ftp, *prev;
68 char *id;
69 const char *name;
70
71 (void) pthread_mutex_lock(&fmd.d_topo_lock);
72
73 fmd.d_stats->ds_topo_drgen.fmds_value.ui64 = fmd_fmri_get_drgen();
74
75 name = fmd.d_rootdir != NULL &&
76 *fmd.d_rootdir != '\0' ? fmd.d_rootdir : NULL;
77
78 /*
79 * Update the topology snapshot.
80 */
81 if ((tp = topo_open(TOPO_VERSION, name, &err)) == NULL)
82 fmd_panic("failed to open topology library: %s",
83 topo_strerror(err));
84
85 ftp = fmd_alloc(sizeof (fmd_topo_t), FMD_SLEEP);
86 ftp->ft_hdl = tp;
87 ftp->ft_time_begin = fmd_time_gethrtime();
88
89 if ((id = topo_snap_hold(tp, NULL, &err)) == NULL)
90 fmd_panic("failed to get topology snapshot: %s",
91 topo_strerror(err));
92
93 topo_hdl_strfree(tp, id);
94
95 ftp->ft_time_end = fmd_time_gethrtime();
96 fmd.d_stats->ds_topo_gen.fmds_value.ui64++;
97
98 /*
99 * We always keep a reference count on the last topo snapshot taken.
100 * Release the previous snapshot (if present), and set the current
101 * reference count to 1.
102 */
103 if ((prev = fmd_list_next(&fmd.d_topo_list)) != NULL)
104 fmd_topo_rele_locked(prev);
105 ftp->ft_refcount = 1;
106 fmd_list_prepend(&fmd.d_topo_list, ftp);
107
108 (void) pthread_mutex_unlock(&fmd.d_topo_lock);
109 }
110
111 fmd_topo_t *
fmd_topo_hold(void)112 fmd_topo_hold(void)
113 {
114 fmd_topo_t *ftp;
115
116 (void) pthread_mutex_lock(&fmd.d_topo_lock);
117 ftp = fmd_list_next(&fmd.d_topo_list);
118 ftp->ft_refcount++;
119 (void) pthread_mutex_unlock(&fmd.d_topo_lock);
120
121 return (ftp);
122 }
123
124 void
fmd_topo_addref(fmd_topo_t * ftp)125 fmd_topo_addref(fmd_topo_t *ftp)
126 {
127 (void) pthread_mutex_lock(&fmd.d_topo_lock);
128 ftp->ft_refcount++;
129 (void) pthread_mutex_unlock(&fmd.d_topo_lock);
130 }
131
132 void
fmd_topo_rele(fmd_topo_t * ftp)133 fmd_topo_rele(fmd_topo_t *ftp)
134 {
135 (void) pthread_mutex_lock(&fmd.d_topo_lock);
136
137 fmd_topo_rele_locked(ftp);
138
139 (void) pthread_mutex_unlock(&fmd.d_topo_lock);
140 }
141
142 void
fmd_topo_rele_hdl(topo_hdl_t * thp)143 fmd_topo_rele_hdl(topo_hdl_t *thp)
144 {
145 fmd_topo_t *ftp;
146
147 (void) pthread_mutex_lock(&fmd.d_topo_lock);
148 for (ftp = fmd_list_next(&fmd.d_topo_list); ftp != NULL;
149 ftp = fmd_list_next(ftp)) {
150 if (ftp->ft_hdl == thp)
151 break;
152 }
153 ASSERT(ftp != NULL);
154
155 fmd_topo_rele_locked(ftp);
156 (void) pthread_mutex_unlock(&fmd.d_topo_lock);
157 }
158
159 void
fmd_topo_init(void)160 fmd_topo_init(void)
161 {
162 fmd_topo_update();
163 }
164
165 void
fmd_topo_fini(void)166 fmd_topo_fini(void)
167 {
168 fmd_topo_t *ftp;
169
170 (void) pthread_mutex_lock(&fmd.d_topo_lock);
171 while ((ftp = fmd_list_next(&fmd.d_topo_list)) != NULL) {
172 fmd_list_delete(&fmd.d_topo_list, ftp);
173 topo_close(ftp->ft_hdl);
174 fmd_free(ftp, sizeof (fmd_topo_t));
175 }
176 (void) pthread_mutex_unlock(&fmd.d_topo_lock);
177 }
178