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 2009 Sun Microsystems, Inc. All rights reserved.
23 * Use is subject to license terms.
24 */
25
26 #include <sys/zfs_context.h>
27 #include <sys/spa.h>
28 #include <sys/vdev_impl.h>
29 #include <sys/zio.h>
30 #include <sys/fs/zfs.h>
31
32 /*
33 * Virtual device vector for the pool's root vdev.
34 */
35
36 /*
37 * We should be able to tolerate one failure with absolutely no damage
38 * to our metadata. Two failures will take out space maps, a bunch of
39 * indirect block trees, meta dnodes, dnodes, etc. Probably not a happy
40 * place to live. When we get smarter, we can liberalize this policy.
41 * e.g. If we haven't lost two consecutive top-level vdevs, then we are
42 * probably fine. Adding bean counters during alloc/free can make this
43 * future guesswork more accurate.
44 */
45 static int
too_many_errors(vdev_t * vd,int numerrors)46 too_many_errors(vdev_t *vd, int numerrors)
47 {
48 ASSERT3U(numerrors, <=, vd->vdev_children);
49 return (numerrors > 0);
50 }
51
52 static int
vdev_root_open(vdev_t * vd,uint64_t * asize,uint64_t * ashift)53 vdev_root_open(vdev_t *vd, uint64_t *asize, uint64_t *ashift)
54 {
55 int lasterror = 0;
56 int numerrors = 0;
57
58 if (vd->vdev_children == 0) {
59 vd->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL;
60 return (EINVAL);
61 }
62
63 vdev_open_children(vd);
64
65 for (int c = 0; c < vd->vdev_children; c++) {
66 vdev_t *cvd = vd->vdev_child[c];
67
68 if (cvd->vdev_open_error && !cvd->vdev_islog) {
69 lasterror = cvd->vdev_open_error;
70 numerrors++;
71 }
72 }
73
74 if (too_many_errors(vd, numerrors)) {
75 vd->vdev_stat.vs_aux = VDEV_AUX_NO_REPLICAS;
76 return (lasterror);
77 }
78
79 *asize = 0;
80 *ashift = 0;
81
82 return (0);
83 }
84
85 static void
vdev_root_close(vdev_t * vd)86 vdev_root_close(vdev_t *vd)
87 {
88 for (int c = 0; c < vd->vdev_children; c++)
89 vdev_close(vd->vdev_child[c]);
90 }
91
92 static void
vdev_root_state_change(vdev_t * vd,int faulted,int degraded)93 vdev_root_state_change(vdev_t *vd, int faulted, int degraded)
94 {
95 if (too_many_errors(vd, faulted)) {
96 vdev_set_state(vd, B_FALSE, VDEV_STATE_CANT_OPEN,
97 VDEV_AUX_NO_REPLICAS);
98 } else if (degraded) {
99 vdev_set_state(vd, B_FALSE, VDEV_STATE_DEGRADED, VDEV_AUX_NONE);
100 } else {
101 vdev_set_state(vd, B_FALSE, VDEV_STATE_HEALTHY, VDEV_AUX_NONE);
102 }
103 }
104
105 vdev_ops_t vdev_root_ops = {
106 vdev_root_open,
107 vdev_root_close,
108 vdev_default_asize,
109 NULL, /* io_start - not applicable to the root */
110 NULL, /* io_done - not applicable to the root */
111 vdev_root_state_change,
112 VDEV_TYPE_ROOT, /* name of this vdev type */
113 B_FALSE /* not a leaf vdev */
114 };
115