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 { 44 struct volume_info *root_volume; 45 hammer_blockmap_t blockmap; 46 hammer_blockmap_t freemap; 47 struct hammer_blockmap_layer1 *layer1; 48 struct hammer_blockmap_layer2 *layer2; 49 struct buffer_info *buffer = NULL; 50 hammer_off_t layer1_offset; 51 hammer_off_t layer2_offset; 52 hammer_off_t result_offset; 53 int zone; 54 int i; 55 56 zone = HAMMER_ZONE_DECODE(zone_offset); 57 58 assert(zone > HAMMER_ZONE_RAW_VOLUME_INDEX); 59 assert(zone < HAMMER_MAX_ZONES); 60 assert(RootVolNo >= 0); 61 root_volume = get_volume(RootVolNo); 62 blockmap = &root_volume->ondisk->vol0_blockmap[zone]; 63 64 if (zone == HAMMER_ZONE_RAW_BUFFER_INDEX) { 65 result_offset = zone_offset; 66 } else if (zone == HAMMER_ZONE_UNDO_INDEX) { 67 i = (zone_offset & HAMMER_OFF_SHORT_MASK) / 68 HAMMER_LARGEBLOCK_SIZE; 69 assert(zone_offset < blockmap->alloc_offset); 70 result_offset = root_volume->ondisk->vol0_undo_array[i] + 71 (zone_offset & HAMMER_LARGEBLOCK_MASK64); 72 } else { 73 result_offset = (zone_offset & ~HAMMER_OFF_ZONE_MASK) | 74 HAMMER_ZONE_RAW_BUFFER; 75 } 76 77 assert(HAMMER_ZONE_DECODE(blockmap->alloc_offset) == zone); 78 79 /* 80 * Validate that the big-block is assigned to the zone. Also 81 * assign save_layer{1,2}. 82 */ 83 84 freemap = &root_volume->ondisk->vol0_blockmap[HAMMER_ZONE_FREEMAP_INDEX]; 85 /* 86 * Dive layer 1. 87 */ 88 layer1_offset = freemap->phys_offset + 89 HAMMER_BLOCKMAP_LAYER1_OFFSET(result_offset); 90 layer1 = get_buffer_data(layer1_offset, &buffer, 0); 91 assert(layer1->phys_offset != HAMMER_BLOCKMAP_UNAVAIL); 92 if (save_layer1) 93 *save_layer1 = *layer1; 94 95 /* 96 * Dive layer 2, each entry represents a large-block. 97 */ 98 layer2_offset = layer1->phys_offset + 99 HAMMER_BLOCKMAP_LAYER2_OFFSET(result_offset); 100 layer2 = get_buffer_data(layer2_offset, &buffer, 0); 101 if (save_layer2) 102 *save_layer2 = *layer2; 103 104 assert(layer2->zone == zone); 105 106 if (buffer) 107 rel_buffer(buffer); 108 rel_volume(root_volume); 109 return(result_offset); 110 } 111 112