1 /* 2 * Copyright (c) 2008 The DragonFly Project. All rights reserved. 3 * 4 * This code is derived from software contributed to The DragonFly Project 5 * by Matthew Dillon <dillon@backplane.com> 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in 15 * the documentation and/or other materials provided with the 16 * distribution. 17 * 3. Neither the name of The DragonFly Project nor the names of its 18 * contributors may be used to endorse or promote products derived 19 * from this software without specific, prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 26 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * $DragonFly: src/sbin/hammer/blockmap.c,v 1.2 2008/06/17 04:03:38 dillon Exp $ 35 */ 36 37 #include "hammer.h" 38 39 hammer_off_t 40 blockmap_lookup(hammer_off_t zone_offset, 41 struct hammer_blockmap_layer1 *save_layer1, 42 struct hammer_blockmap_layer2 *save_layer2, 43 int *errorp) 44 { 45 struct volume_info *root_volume = NULL; 46 hammer_blockmap_t blockmap; 47 hammer_blockmap_t freemap; 48 struct hammer_blockmap_layer1 *layer1; 49 struct hammer_blockmap_layer2 *layer2; 50 struct buffer_info *buffer1 = NULL; 51 struct buffer_info *buffer2 = NULL; 52 hammer_off_t layer1_offset; 53 hammer_off_t layer2_offset; 54 hammer_off_t result_offset; 55 int zone; 56 int i; 57 int error = 0; 58 59 if (save_layer1) 60 bzero(save_layer1, sizeof(*save_layer1)); 61 if (save_layer2) 62 bzero(save_layer2, sizeof(*save_layer2)); 63 64 zone = HAMMER_ZONE_DECODE(zone_offset); 65 66 if (zone <= HAMMER_ZONE_RAW_VOLUME_INDEX) 67 error = -1; 68 if (zone >= HAMMER_MAX_ZONES) 69 error = -2; 70 if (RootVolNo < 0) 71 error = -3; 72 if (error) { 73 result_offset = HAMMER_OFF_BAD; 74 goto done; 75 } 76 77 root_volume = get_volume(RootVolNo); 78 blockmap = &root_volume->ondisk->vol0_blockmap[zone]; 79 80 if (zone == HAMMER_ZONE_RAW_BUFFER_INDEX) { 81 result_offset = zone_offset; 82 } else if (zone == HAMMER_ZONE_UNDO_INDEX) { 83 i = (zone_offset & HAMMER_OFF_SHORT_MASK) / 84 HAMMER_BIGBLOCK_SIZE; 85 if (zone_offset >= blockmap->alloc_offset) { 86 error = -4; 87 result_offset = HAMMER_OFF_BAD; 88 goto done; 89 } 90 result_offset = root_volume->ondisk->vol0_undo_array[i] + 91 (zone_offset & HAMMER_BIGBLOCK_MASK64); 92 } else { 93 result_offset = hammer_xlate_to_zone2(zone_offset); 94 } 95 96 /* 97 * The blockmap should match the requested zone (else the volume 98 * header is mashed). 99 * 100 * Note that a valid offset can still be returned if AssertOnFailure 101 * is zero. 102 */ 103 if (HAMMER_ZONE_FREEMAP_INDEX != zone && 104 HAMMER_ZONE_DECODE(blockmap->alloc_offset) != zone) { 105 error = -5; 106 goto done; 107 } 108 109 /* 110 * Validate that the big-block is assigned to the zone. Also 111 * assign save_layer{1,2}. 112 */ 113 114 freemap = &root_volume->ondisk->vol0_blockmap[HAMMER_ZONE_FREEMAP_INDEX]; 115 /* 116 * Dive layer 1. 117 */ 118 layer1_offset = freemap->phys_offset + 119 HAMMER_BLOCKMAP_LAYER1_OFFSET(result_offset); 120 layer1 = get_buffer_data(layer1_offset, &buffer1, 0); 121 if (layer1 == NULL) { 122 error = -6; 123 goto done; 124 } 125 if (layer1->phys_offset == HAMMER_BLOCKMAP_UNAVAIL) { 126 error = -7; 127 goto done; 128 } 129 130 if (save_layer1) 131 *save_layer1 = *layer1; 132 133 /* 134 * Dive layer 2, each entry represents a big-block. 135 */ 136 layer2_offset = layer1->phys_offset + 137 HAMMER_BLOCKMAP_LAYER2_OFFSET(result_offset); 138 layer2 = get_buffer_data(layer2_offset, &buffer2, 0); 139 140 if (layer2 == NULL) { 141 error = -8; 142 goto done; 143 } 144 if (layer2->zone != zone) { 145 error = -9; 146 goto done; 147 } 148 if (save_layer2) 149 *save_layer2 = *layer2; 150 151 done: 152 rel_buffer(buffer1); 153 rel_buffer(buffer2); 154 rel_volume(root_volume); 155 156 if (AssertOnFailure && error != 0) 157 errx(1, "blockmap_lookup: error=%d\n", error); 158 if (errorp) 159 *errorp = error; 160 161 return(result_offset); 162 } 163 164