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 2008 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 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 53 vdev_root_open(vdev_t *vd, uint64_t *asize, uint64_t *ashift) 54 { 55 int c; 56 int lasterror = 0; 57 int numerrors = 0; 58 59 if (vd->vdev_children == 0) { 60 vd->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL; 61 return (EINVAL); 62 } 63 64 for (c = 0; c < vd->vdev_children; c++) { 65 vdev_t *cvd = vd->vdev_child[c]; 66 int error; 67 68 if ((error = vdev_open(cvd)) != 0 && 69 !cvd->vdev_islog) { 70 lasterror = error; 71 numerrors++; 72 continue; 73 } 74 } 75 76 if (too_many_errors(vd, numerrors)) { 77 vd->vdev_stat.vs_aux = VDEV_AUX_NO_REPLICAS; 78 return (lasterror); 79 } 80 81 *asize = 0; 82 *ashift = 0; 83 84 return (0); 85 } 86 87 static void 88 vdev_root_close(vdev_t *vd) 89 { 90 int c; 91 92 for (c = 0; c < vd->vdev_children; c++) 93 vdev_close(vd->vdev_child[c]); 94 } 95 96 static void 97 vdev_root_state_change(vdev_t *vd, int faulted, int degraded) 98 { 99 if (too_many_errors(vd, faulted)) { 100 vdev_set_state(vd, B_FALSE, VDEV_STATE_CANT_OPEN, 101 VDEV_AUX_NO_REPLICAS); 102 } else if (degraded) { 103 vdev_set_state(vd, B_FALSE, VDEV_STATE_DEGRADED, VDEV_AUX_NONE); 104 } else { 105 vdev_set_state(vd, B_FALSE, VDEV_STATE_HEALTHY, VDEV_AUX_NONE); 106 } 107 } 108 109 vdev_ops_t vdev_root_ops = { 110 vdev_root_open, 111 vdev_root_close, 112 vdev_default_asize, 113 NULL, /* io_start - not applicable to the root */ 114 NULL, /* io_done - not applicable to the root */ 115 vdev_root_state_change, 116 VDEV_TYPE_ROOT, /* name of this vdev type */ 117 B_FALSE /* not a leaf vdev */ 118 }; 119