2 * Copyright (c) 2008 The DragonFly Project. All rights reserved.
4 * This code is derived from software contributed to The DragonFly Project
5 * by Matthew Dillon <dillon@backplane.com>
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
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
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.
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
34 * $DragonFly: src/sbin/hammer/blockmap.c,v 1.2 2008/06/17 04:03:38 dillon Exp $
40 blockmap_lookup(hammer_off_t zone_offset,
41 struct hammer_blockmap_layer1 *save_layer1,
42 struct hammer_blockmap_layer2 *save_layer2,
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;
58 zone = HAMMER_ZONE_DECODE(zone_offset);
60 if (AssertOnFailure) {
61 assert(zone > HAMMER_ZONE_RAW_VOLUME_INDEX);
62 assert(zone < HAMMER_MAX_ZONES);
63 assert(RootVolNo >= 0);
65 if (zone <= HAMMER_ZONE_RAW_VOLUME_INDEX)
67 if (zone >= HAMMER_MAX_ZONES)
72 result_offset = HAMMER_OFF_BAD;
77 root_volume = get_volume(RootVolNo);
78 blockmap = &root_volume->ondisk->vol0_blockmap[zone];
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_LARGEBLOCK_SIZE;
85 if (AssertOnFailure) {
86 assert(zone_offset < blockmap->alloc_offset);
88 if (zone_offset >= blockmap->alloc_offset) {
90 result_offset = HAMMER_OFF_BAD;
94 result_offset = root_volume->ondisk->vol0_undo_array[i] +
95 (zone_offset & HAMMER_LARGEBLOCK_MASK64);
97 result_offset = (zone_offset & ~HAMMER_OFF_ZONE_MASK) |
98 HAMMER_ZONE_RAW_BUFFER;
102 * The blockmap should match the requested zone (else the volume
105 if (AssertOnFailure) {
106 assert(HAMMER_ZONE_DECODE(blockmap->alloc_offset) == zone);
108 if (HAMMER_ZONE_DECODE(blockmap->alloc_offset) != zone) {
115 * Validate that the big-block is assigned to the zone. Also
116 * assign save_layer{1,2}.
119 freemap = &root_volume->ondisk->vol0_blockmap[HAMMER_ZONE_FREEMAP_INDEX];
123 layer1_offset = freemap->phys_offset +
124 HAMMER_BLOCKMAP_LAYER1_OFFSET(result_offset);
125 layer1 = get_buffer_data(layer1_offset, &buffer, 0);
126 if (AssertOnFailure) {
127 assert(layer1->phys_offset != HAMMER_BLOCKMAP_UNAVAIL);
129 if (layer1->phys_offset == HAMMER_BLOCKMAP_UNAVAIL) {
135 *save_layer1 = *layer1;
138 * Dive layer 2, each entry represents a large-block.
140 layer2_offset = layer1->phys_offset +
141 HAMMER_BLOCKMAP_LAYER2_OFFSET(result_offset);
142 layer2 = get_buffer_data(layer2_offset, &buffer, 0);
144 *save_layer2 = *layer2;
146 if (AssertOnFailure) {
147 assert(layer2->zone == zone);
149 if (layer2->zone != zone)
157 rel_volume(root_volume);
162 return(result_offset);