sbin/hammer/blockmap.c

   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                 *save_layer1 = NULL;
  60         if (save_layer2)
  61                 *save_layer2 = NULL;
  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