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 by Delphix. All rights reserved. 28 */ 29 30 #include <sys/zfs_context.h> 31 #include <sys/spa.h> 32 #include <sys/vdev_impl.h> 33 #include <sys/zio.h> 34 #include <sys/fs/zfs.h> 35 36 /* 37 * Virtual device vector for the pool's root vdev. 38 */ 39 40 /* 41 * We should be able to tolerate one failure with absolutely no damage 42 * to our metadata. Two failures will take out space maps, a bunch of 43 * indirect block trees, meta dnodes, dnodes, etc. Probably not a happy 44 * place to live. When we get smarter, we can liberalize this policy. 45 * e.g. If we haven't lost two consecutive top-level vdevs, then we are 46 * probably fine. Adding bean counters during alloc/free can make this 47 * future guesswork more accurate. 48 */ 49 static int 50 too_many_errors(vdev_t *vd, int numerrors) 51 { 52 ASSERT3U(numerrors, <=, vd->vdev_children); 53 return (numerrors > 0); 54 } 55 56 static int 57 vdev_root_open(vdev_t *vd, uint64_t *asize, uint64_t *max_asize, 58 uint64_t *ashift) 59 { 60 int lasterror = 0; 61 int numerrors = 0; 62 63 if (vd->vdev_children == 0) { 64 vd->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL; 65 return (EINVAL); 66 } 67 68 vdev_open_children(vd); 69 70 for (int c = 0; c < vd->vdev_children; c++) { 71 vdev_t *cvd = vd->vdev_child[c]; 72 73 if (cvd->vdev_open_error && !cvd->vdev_islog) { 74 lasterror = cvd->vdev_open_error; 75 numerrors++; 76 } 77 } 78 79 if (too_many_errors(vd, numerrors)) { 80 vd->vdev_stat.vs_aux = VDEV_AUX_NO_REPLICAS; 81 return (lasterror); 82 } 83 84 *asize = 0; 85 *max_asize = 0; 86 *ashift = 0; 87 88 return (0); 89 } 90 91 static void 92 vdev_root_close(vdev_t *vd) 93 { 94 for (int c = 0; c < vd->vdev_children; c++) 95 vdev_close(vd->vdev_child[c]); 96 } 97 98 static void 99 vdev_root_state_change(vdev_t *vd, int faulted, int degraded) 100 { 101 if (too_many_errors(vd, faulted)) { 102 vdev_set_state(vd, B_FALSE, VDEV_STATE_CANT_OPEN, 103 VDEV_AUX_NO_REPLICAS); 104 } else if (degraded) { 105 vdev_set_state(vd, B_FALSE, VDEV_STATE_DEGRADED, VDEV_AUX_NONE); 106 } else { 107 vdev_set_state(vd, B_FALSE, VDEV_STATE_HEALTHY, VDEV_AUX_NONE); 108 } 109 } 110 111 vdev_ops_t vdev_root_ops = { 112 vdev_root_open, 113 vdev_root_close, 114 vdev_default_asize, 115 NULL, /* io_start - not applicable to the root */ 116 NULL, /* io_done - not applicable to the root */ 117 vdev_root_state_change, 118 NULL, 119 NULL, 120 VDEV_TYPE_ROOT, /* name of this vdev type */ 121 B_FALSE /* not a leaf vdev */ 122 }; 123