xref: /illumos-gate/usr/src/uts/common/fs/zfs/vdev_root.c (revision ac04831df9010f533275633d3bb9829b86c171d3)
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 2010 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 /*
27  * Copyright (c) 2012, 2016 by Delphix. All rights reserved.
28  * Copyright 2019 Joyent, Inc.
29  */
30 
31 #include <sys/zfs_context.h>
32 #include <sys/spa.h>
33 #include <sys/vdev_impl.h>
34 #include <sys/zio.h>
35 #include <sys/fs/zfs.h>
36 
37 /*
38  * Virtual device vector for the pool's root vdev.
39  */
40 
41 static uint64_t
vdev_root_core_tvds(vdev_t * vd)42 vdev_root_core_tvds(vdev_t *vd)
43 {
44 	uint64_t tvds = 0;
45 
46 	for (uint64_t c = 0; c < vd->vdev_children; c++) {
47 		vdev_t *cvd = vd->vdev_child[c];
48 
49 		if (!cvd->vdev_ishole && !cvd->vdev_islog &&
50 		    cvd->vdev_ops != &vdev_indirect_ops) {
51 			tvds++;
52 		}
53 	}
54 
55 	return (tvds);
56 }
57 
58 /*
59  * We should be able to tolerate one failure with absolutely no damage
60  * to our metadata.  Two failures will take out space maps, a bunch of
61  * indirect block trees, meta dnodes, dnodes, etc.  Probably not a happy
62  * place to live.  When we get smarter, we can liberalize this policy.
63  * e.g. If we haven't lost two consecutive top-level vdevs, then we are
64  * probably fine.  Adding bean counters during alloc/free can make this
65  * future guesswork more accurate.
66  */
67 static boolean_t
too_many_errors(vdev_t * vd,uint64_t numerrors)68 too_many_errors(vdev_t *vd, uint64_t numerrors)
69 {
70 	uint64_t tvds;
71 
72 	if (numerrors == 0)
73 		return (B_FALSE);
74 
75 	tvds = vdev_root_core_tvds(vd);
76 	ASSERT3U(numerrors, <=, tvds);
77 
78 	if (numerrors == tvds)
79 		return (B_TRUE);
80 
81 	return (numerrors > spa_missing_tvds_allowed(vd->vdev_spa));
82 }
83 
84 static int
vdev_root_open(vdev_t * vd,uint64_t * asize,uint64_t * max_asize,uint64_t * ashift)85 vdev_root_open(vdev_t *vd, uint64_t *asize, uint64_t *max_asize,
86     uint64_t *ashift)
87 {
88 	spa_t *spa = vd->vdev_spa;
89 	int lasterror = 0;
90 	int numerrors = 0;
91 
92 	if (vd->vdev_children == 0) {
93 		vd->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL;
94 		return (SET_ERROR(EINVAL));
95 	}
96 
97 	vdev_open_children(vd);
98 
99 	for (int c = 0; c < vd->vdev_children; c++) {
100 		vdev_t *cvd = vd->vdev_child[c];
101 
102 		if (cvd->vdev_open_error && !cvd->vdev_islog) {
103 			lasterror = cvd->vdev_open_error;
104 			numerrors++;
105 		}
106 	}
107 
108 	if (spa_load_state(spa) != SPA_LOAD_NONE)
109 		spa_set_missing_tvds(spa, numerrors);
110 
111 	if (too_many_errors(vd, numerrors)) {
112 		vd->vdev_stat.vs_aux = VDEV_AUX_NO_REPLICAS;
113 		return (lasterror);
114 	}
115 
116 	*asize = 0;
117 	*max_asize = 0;
118 	*ashift = 0;
119 
120 	return (0);
121 }
122 
123 static void
vdev_root_close(vdev_t * vd)124 vdev_root_close(vdev_t *vd)
125 {
126 	for (int c = 0; c < vd->vdev_children; c++)
127 		vdev_close(vd->vdev_child[c]);
128 }
129 
130 static void
vdev_root_state_change(vdev_t * vd,int faulted,int degraded)131 vdev_root_state_change(vdev_t *vd, int faulted, int degraded)
132 {
133 	if (too_many_errors(vd, faulted)) {
134 		vdev_set_state(vd, B_FALSE, VDEV_STATE_CANT_OPEN,
135 		    VDEV_AUX_NO_REPLICAS);
136 	} else if (degraded || faulted) {
137 		vdev_set_state(vd, B_FALSE, VDEV_STATE_DEGRADED, VDEV_AUX_NONE);
138 	} else {
139 		vdev_set_state(vd, B_FALSE, VDEV_STATE_HEALTHY, VDEV_AUX_NONE);
140 	}
141 }
142 
143 vdev_ops_t vdev_root_ops = {
144 	.vdev_op_open = vdev_root_open,
145 	.vdev_op_close = vdev_root_close,
146 	.vdev_op_asize = vdev_default_asize,
147 	.vdev_op_io_start = NULL,	/* not applicable to the root */
148 	.vdev_op_io_done = NULL,	/* not applicable to the root */
149 	.vdev_op_state_change = vdev_root_state_change,
150 	.vdev_op_need_resilver = NULL,
151 	.vdev_op_hold = NULL,
152 	.vdev_op_rele = NULL,
153 	.vdev_op_remap = NULL,
154 	.vdev_op_xlate = NULL,
155 	.vdev_op_dumpio = NULL,
156 	.vdev_op_type = VDEV_TYPE_ROOT,	/* name of this vdev type */
157 	.vdev_op_leaf = B_FALSE		/* not a leaf vdev */
158 };
159