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
41static uint64_t
42vdev_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 */
67static boolean_t
68too_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
84static int
85vdev_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
123static void
124vdev_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
130static void
131vdev_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
143vdev_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