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 *buffer = NULL; 51 hammer_off_t layer1_offset; 52 hammer_off_t layer2_offset; 53 hammer_off_t result_offset; 54 int zone; 55 int i; 56 int error = 0; 57 58 if (save_layer1) 59 bzero(save_layer1, sizeof(*save_layer1)); 60 if (save_layer2) 61 bzero(save_layer2, sizeof(*save_layer2)); 62 63 zone = HAMMER_ZONE_DECODE(zone_offset); 64 65 if (AssertOnFailure) { 66 assert(zone > HAMMER_ZONE_RAW_VOLUME_INDEX); 67 assert(zone < HAMMER_MAX_ZONES); 68 assert(RootVolNo >= 0); 69 } else { 70 if (zone <= HAMMER_ZONE_RAW_VOLUME_INDEX) 71 error = EDOM; 72 if (zone >= HAMMER_MAX_ZONES) 73 error = EDOM; 74 if (RootVolNo < 0) 75 error = EDOM; 76 if (error) { 77 result_offset = HAMMER_OFF_BAD; 78 goto done; 79 } 80 } 81 82 root_volume = get_volume(RootVolNo); 83 blockmap = &root_volume->ondisk->vol0_blockmap[zone]; 84 85 if (zone == HAMMER_ZONE_RAW_BUFFER_INDEX) { 86 result_offset = zone_offset; 87 } else if (zone == HAMMER_ZONE_UNDO_INDEX) { 88 i = (zone_offset & HAMMER_OFF_SHORT_MASK) / 89 HAMMER_LARGEBLOCK_SIZE; 90 if (AssertOnFailure) { 91 assert(zone_offset < blockmap->alloc_offset); 92 } else { 93 if (zone_offset >= blockmap->alloc_offset) { 94 error = EDOM; 95 result_offset = HAMMER_OFF_BAD; 96 goto done; 97 } 98 } 99 result_offset = root_volume->ondisk->vol0_undo_array[i] + 100 (zone_offset & HAMMER_LARGEBLOCK_MASK64); 101 } else { 102 result_offset = (zone_offset & ~HAMMER_OFF_ZONE_MASK) | 103 HAMMER_ZONE_RAW_BUFFER; 104 } 105 106 /* 107 * The blockmap should match the requested zone (else the volume 108 * header is mashed). 109 * 110 * Note that a valid offset can still be returned if AssertOnFailure 111 * is zero. 112 */ 113 if (AssertOnFailure) { 114 assert(HAMMER_ZONE_DECODE(blockmap->alloc_offset) == zone); 115 } else { 116 if (HAMMER_ZONE_DECODE(blockmap->alloc_offset) != zone) { 117 error = EDOM; 118 goto done; 119 } 120 } 121 122 /* 123 * Validate that the big-block is assigned to the zone. Also 124 * assign save_layer{1,2}. 125 */ 126 127 freemap = &root_volume->ondisk->vol0_blockmap[HAMMER_ZONE_FREEMAP_INDEX]; 128 /* 129 * Dive layer 1. 130 */ 131 layer1_offset = freemap->phys_offset + 132 HAMMER_BLOCKMAP_LAYER1_OFFSET(result_offset); 133 layer1 = get_buffer_data(layer1_offset, &buffer, 0); 134 if (AssertOnFailure) { 135 assert(layer1); 136 assert(layer1->phys_offset != HAMMER_BLOCKMAP_UNAVAIL); 137 } else { 138 if (layer1 == NULL) { 139 error = EDOM; 140 goto done; 141 } 142 if (layer1->phys_offset == HAMMER_BLOCKMAP_UNAVAIL) { 143 error = EDOM; 144 goto done; 145 } 146 } 147 if (save_layer1) 148 *save_layer1 = *layer1; 149 150 /* 151 * Dive layer 2, each entry represents a large-block. 152 */ 153 layer2_offset = layer1->phys_offset + 154 HAMMER_BLOCKMAP_LAYER2_OFFSET(result_offset); 155 layer2 = get_buffer_data(layer2_offset, &buffer, 0); 156 157 if (AssertOnFailure) { 158 assert(layer2); 159 assert(layer2->zone == zone); 160 } else { 161 if (layer2 == NULL) { 162 error = EDOM; 163 goto done; 164 } 165 if (layer2->zone != zone) { 166 error = EDOM; 167 goto done; 168 } 169 } 170 if (save_layer2) 171 *save_layer2 = *layer2; 172 173 done: 174 if (buffer) 175 rel_buffer(buffer); 176 if (root_volume) 177 rel_volume(root_volume); 178 179 if (errorp) 180 *errorp = error; 181 182 return(result_offset); 183 } 184 185