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 1.1 2008/02/23 03:01:06 dillon Exp $ 35 */ 36 37 #include "hammer.h" 38 39 hammer_off_t 40 blockmap_lookup(hammer_off_t bmap_off, 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 rootmap; 46 struct hammer_blockmap_layer1 *layer1; 47 struct hammer_blockmap_layer2 *layer2; 48 struct buffer_info *buffer = NULL; 49 hammer_off_t layer1_offset; 50 hammer_off_t layer2_offset; 51 hammer_off_t result_offset; 52 int zone; 53 54 zone = HAMMER_ZONE_DECODE(bmap_off); 55 assert(zone >= HAMMER_ZONE_BTREE_INDEX && zone < HAMMER_MAX_ZONES); 56 assert(RootVolNo >= 0); 57 root_volume = get_volume(RootVolNo); 58 rootmap = &root_volume->ondisk->vol0_blockmap[zone]; 59 assert(rootmap->phys_offset != 0); 60 assert(HAMMER_ZONE_DECODE(rootmap->phys_offset) == 61 HAMMER_ZONE_RAW_BUFFER_INDEX); 62 assert(HAMMER_ZONE_DECODE(rootmap->alloc_offset) == zone); 63 64 if (bmap_off >= rootmap->alloc_offset) { 65 panic("hammer_blockmap_lookup: %016llx beyond EOF %016llx", 66 bmap_off, rootmap->alloc_offset); 67 result_offset = 0; 68 goto done; 69 } 70 71 /* 72 * Dive layer 1. 73 */ 74 layer1_offset = rootmap->phys_offset + 75 HAMMER_BLOCKMAP_LAYER1_OFFSET(bmap_off); 76 layer1 = get_buffer_data(layer1_offset, &buffer, 0); 77 assert(layer1->phys_offset); 78 if (save_layer1) 79 *save_layer1 = *layer1; 80 81 /* 82 * Dive layer 2, each entry represents a large-block. 83 */ 84 layer2_offset = layer1->phys_offset + 85 HAMMER_BLOCKMAP_LAYER2_OFFSET(bmap_off); 86 layer2 = get_buffer_data(layer2_offset, &buffer, 0); 87 if (save_layer2) 88 *save_layer2 = *layer2; 89 90 assert(layer2->u.phys_offset); 91 92 result_offset = layer2->u.phys_offset + 93 (bmap_off & HAMMER_LARGEBLOCK_MASK64); 94 done: 95 if (buffer) 96 rel_buffer(buffer); 97 rel_volume(root_volume); 98 return(result_offset); 99 } 100 101