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 1.1 2008/02/23 03:01:06 dillon Exp $
40 blockmap_lookup(hammer_off_t bmap_off,
41 struct hammer_blockmap_layer1 *save_layer1,
42 struct hammer_blockmap_layer2 *save_layer2)
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;
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);
64 if (bmap_off >= rootmap->alloc_offset) {
65 panic("hammer_blockmap_lookup: %016llx beyond EOF %016llx",
66 bmap_off, rootmap->alloc_offset);
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);
79 *save_layer1 = *layer1;
82 * Dive layer 2, each entry represents a large-block.
84 layer2_offset = layer1->phys_offset +
85 HAMMER_BLOCKMAP_LAYER2_OFFSET(bmap_off);
86 layer2 = get_buffer_data(layer2_offset, &buffer, 0);
88 *save_layer2 = *layer2;
90 assert(layer2->u.phys_offset);
92 result_offset = layer2->u.phys_offset +
93 (bmap_off & HAMMER_LARGEBLOCK_MASK64);
97 rel_volume(root_volume);
98 return(result_offset);