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_util.h"
  38
  39 /*
  40  * Allocate big-blocks using our poor-man's volume->vol_free_off.
  41  * We are bootstrapping the freemap itself and cannot update it yet.
  42  */
  43 hammer_off_t
  44 bootstrap_bigblock(struct volume_info *volume)
  45 {
  46         hammer_off_t result_offset;
  47
  48         assert_volume_offset(volume);
  49         result_offset = volume->vol_free_off;
  50
  51         volume->vol_free_off += HAMMER_BIGBLOCK_SIZE;
  52
  53         return(result_offset);
  54 }
  55
  56 /*
  57  * Allocate a big-block for zone-3 for UNDO/REDO FIFO.
  58  */
  59 hammer_off_t
  60 alloc_undo_bigblock(struct volume_info *volume)
  61 {
  62         hammer_blockmap_t freemap;
  63         struct buffer_info *buffer1 = NULL;
  64         struct buffer_info *buffer2 = NULL;
  65         hammer_blockmap_layer1_t layer1;
  66         hammer_blockmap_layer2_t layer2;
  67         hammer_off_t layer1_offset;
  68         hammer_off_t layer2_offset;
  69         hammer_off_t result_offset;
  70
  71         /* Only root volume needs formatting */
  72         assert(volume->vol_no == HAMMER_ROOT_VOLNO);
  73
  74         result_offset = bootstrap_bigblock(volume);
  75         freemap = &volume->ondisk->vol0_blockmap[HAMMER_ZONE_FREEMAP_INDEX];
  76
  77         /*
  78          * Dive layer 1.
  79          */
  80         layer1_offset = freemap->phys_offset +
  81                         HAMMER_BLOCKMAP_LAYER1_OFFSET(result_offset);
  82         layer1 = get_buffer_data(layer1_offset, &buffer1, 0);
  83         assert(layer1->phys_offset != HAMMER_BLOCKMAP_UNAVAIL);
  84         --layer1->blocks_free;
  85         hammer_crc_set_layer1(layer1);
  86         buffer1->cache.modified = 1;
  87
  88         /*
  89          * Dive layer 2, each entry represents a big-block.
  90          */
  91         layer2_offset = layer1->phys_offset +
  92                         HAMMER_BLOCKMAP_LAYER2_OFFSET(result_offset);
  93         layer2 = get_buffer_data(layer2_offset, &buffer2, 0);
  94         assert(layer2->zone == 0);
  95         layer2->zone = HAMMER_ZONE_UNDO_INDEX;
  96         layer2->append_off = HAMMER_BIGBLOCK_SIZE;
  97         layer2->bytes_free = 0;
  98         hammer_crc_set_layer2(layer2);
  99         buffer2->cache.modified = 1;
 100
 101         --volume->ondisk->vol0_stat_freebigblocks;
 102
 103         rel_buffer(buffer1);
 104         rel_buffer(buffer2);
 105
 106         return(result_offset);
 107 }
 108
 109 /*
 110  * Allocate a chunk of data out of a blockmap.  This is a simplified
 111  * version which uses next_offset as a simple allocation iterator.
 112  */
 113 void *
 114 alloc_blockmap(int zone, int bytes, hammer_off_t *result_offp,
 115                struct buffer_info **bufferp)
 116 {
 117         struct volume_info *volume;
 118         hammer_blockmap_t blockmap;
 119         hammer_blockmap_t freemap;
 120         struct buffer_info *buffer1 = NULL;
 121         struct buffer_info *buffer2 = NULL;
 122         hammer_blockmap_layer1_t layer1;
 123         hammer_blockmap_layer2_t layer2;
 124         hammer_off_t tmp_offset;
 125         hammer_off_t layer1_offset;
 126         hammer_off_t layer2_offset;
 127         hammer_off_t block_offset;
 128         void *ptr;
 129
 130         volume = get_root_volume();
 131
 132         blockmap = &volume->ondisk->vol0_blockmap[zone];
 133         freemap = &volume->ondisk->vol0_blockmap[HAMMER_ZONE_FREEMAP_INDEX];
 134         assert(HAMMER_ZONE_DECODE(blockmap->next_offset) == zone);
 135
 136         /*
 137          * Alignment and buffer-boundary issues.  If the allocation would
 138          * cross a buffer boundary we have to skip to the next buffer.
 139          */
 140         bytes = HAMMER_DATA_DOALIGN(bytes);
 141         assert(bytes > 0 && bytes <= HAMMER_BUFSIZE);  /* not HAMMER_XBUFSIZE */
 142         assert(hammer_is_zone2_mapped_index(zone));
 143
 144 again:
 145         assert(blockmap->next_offset != HAMMER_ZONE_ENCODE(zone + 1, 0));
 146
 147         tmp_offset = blockmap->next_offset + bytes - 1;
 148         if ((blockmap->next_offset ^ tmp_offset) & ~HAMMER_BUFMASK64) {
 149                 blockmap->next_offset = tmp_offset & ~HAMMER_BUFMASK64;
 150         }
 151         block_offset = blockmap->next_offset & HAMMER_BIGBLOCK_MASK;
 152
 153         /*
 154          * Dive layer 1.
 155          */
 156         layer1_offset = freemap->phys_offset +
 157                         HAMMER_BLOCKMAP_LAYER1_OFFSET(blockmap->next_offset);
 158         layer1 = get_buffer_data(layer1_offset, &buffer1, 0);
 159         assert(layer1->phys_offset != HAMMER_BLOCKMAP_UNAVAIL);
 160         assert(!(block_offset == 0 && layer1->blocks_free == 0));
 161
 162         /*
 163          * Dive layer 2, each entry represents a big-block.
 164          */
 165         layer2_offset = layer1->phys_offset +
 166                         HAMMER_BLOCKMAP_LAYER2_OFFSET(blockmap->next_offset);
 167         layer2 = get_buffer_data(layer2_offset, &buffer2, 0);
 168
 169         if (layer2->zone == HAMMER_ZONE_UNAVAIL_INDEX) {
 170                 fprintf(stderr, "alloc_blockmap: layer2 ran out of space!\n");
 171                 exit(1);
 172         }
 173
 174         /*
 175          * If we are entering a new big-block assign ownership to our
 176          * zone.  If the big-block is owned by another zone skip it.
 177          */
 178         if (layer2->zone == 0) {
 179                 --layer1->blocks_free;
 180                 hammer_crc_set_layer1(layer1);
 181                 layer2->zone = zone;
 182                 --volume->ondisk->vol0_stat_freebigblocks;
 183                 assert(layer2->bytes_free == HAMMER_BIGBLOCK_SIZE);
 184                 assert(layer2->append_off == 0);
 185         }
 186         if (layer2->zone != zone) {
 187                 blockmap->next_offset =
 188                         HAMMER_ZONE_LAYER2_NEXT_OFFSET(blockmap->next_offset);
 189                 goto again;
 190         }
 191
 192         assert(layer2->append_off == block_offset);
 193         layer2->bytes_free -= bytes;
 194         *result_offp = blockmap->next_offset;
 195         blockmap->next_offset += bytes;
 196         layer2->append_off = (int)blockmap->next_offset & HAMMER_BIGBLOCK_MASK;
 197         hammer_crc_set_layer2(layer2);
 198
 199         ptr = get_buffer_data(*result_offp, bufferp, 0);
 200         (*bufferp)->cache.modified = 1;
 201
 202         buffer1->cache.modified = 1;
 203         buffer2->cache.modified = 1;
 204
 205         rel_buffer(buffer1);
 206         rel_buffer(buffer2);
 207         return(ptr);
 208 }
 209
 210 hammer_off_t
 211 blockmap_lookup(hammer_off_t zone_offset,
 212                 hammer_blockmap_layer1_t save_layer1,
 213                 hammer_blockmap_layer2_t save_layer2,
 214                 int *errorp)
 215 {
 216         struct volume_info *root_volume = NULL;
 217         hammer_volume_ondisk_t ondisk;
 218         hammer_blockmap_t blockmap;
 219         hammer_blockmap_t freemap;
 220         hammer_blockmap_layer1_t layer1;
 221         hammer_blockmap_layer2_t layer2;
 222         struct buffer_info *buffer1 = NULL;
 223         struct buffer_info *buffer2 = NULL;
 224         hammer_off_t layer1_offset;
 225         hammer_off_t layer2_offset;
 226         hammer_off_t result_offset;
 227         int zone;
 228         int error = 0;
 229
 230         if (save_layer1)
 231                 bzero(save_layer1, sizeof(*save_layer1));
 232         if (save_layer2)
 233                 bzero(save_layer2, sizeof(*save_layer2));
 234
 235         zone = HAMMER_ZONE_DECODE(zone_offset);
 236
 237         if (zone <= HAMMER_ZONE_RAW_VOLUME_INDEX)
 238                 error = -1;
 239         if (zone >= HAMMER_MAX_ZONES)
 240                 error = -2;
 241         if (error) {
 242                 result_offset = HAMMER_OFF_BAD;
 243                 goto done;
 244         }
 245
 246         root_volume = get_root_volume();
 247         ondisk = root_volume->ondisk;
 248         blockmap = &ondisk->vol0_blockmap[zone];
 249
 250         if (zone == HAMMER_ZONE_RAW_BUFFER_INDEX) {
 251                 result_offset = zone_offset;
 252         } else if (zone == HAMMER_ZONE_UNDO_INDEX) {
 253                 if (zone_offset >= blockmap->alloc_offset) {
 254                         error = -3;
 255                         result_offset = HAMMER_OFF_BAD;
 256                         goto done;
 257                 }
 258                 result_offset = hammer_xlate_to_undo(ondisk, zone_offset);
 259         } else {
 260                 result_offset = hammer_xlate_to_zone2(zone_offset);
 261         }
 262
 263         /*
 264          * The blockmap should match the requested zone (else the volume
 265          * header is mashed).
 266          */
 267         if (HAMMER_ZONE_FREEMAP_INDEX != zone &&
 268             HAMMER_ZONE_DECODE(blockmap->alloc_offset) != zone) {
 269                 error = -4;
 270                 goto done;
 271         }
 272
 273         /*
 274          * Validate that the big-block is assigned to the zone.  Also
 275          * assign save_layer{1,2}.
 276          */
 277
 278         freemap = &ondisk->vol0_blockmap[HAMMER_ZONE_FREEMAP_INDEX];
 279         /*
 280          * Dive layer 1.
 281          */
 282         layer1_offset = freemap->phys_offset +
 283                         HAMMER_BLOCKMAP_LAYER1_OFFSET(result_offset);
 284         layer1 = get_buffer_data(layer1_offset, &buffer1, 0);
 285         if (layer1 == NULL) {
 286                 error = -5;
 287                 goto done;
 288         }
 289         if (layer1->phys_offset == HAMMER_BLOCKMAP_UNAVAIL) {
 290                 error = -6;
 291                 goto done;
 292         }
 293
 294         if (save_layer1)
 295                 *save_layer1 = *layer1;
 296
 297         /*
 298          * Dive layer 2, each entry represents a big-block.
 299          */
 300         layer2_offset = layer1->phys_offset +
 301                         HAMMER_BLOCKMAP_LAYER2_OFFSET(result_offset);
 302         layer2 = get_buffer_data(layer2_offset, &buffer2, 0);
 303
 304         if (layer2 == NULL) {
 305                 error = -7;
 306                 goto done;
 307         }
 308         if (layer2->zone != zone) {
 309                 error = -8;
 310                 goto done;
 311         }
 312         if (save_layer2)
 313                 *save_layer2 = *layer2;
 314
 315 done:
 316         rel_buffer(buffer1);
 317         rel_buffer(buffer2);
 318
 319         if (errorp)
 320                 *errorp = error;
 321
 322         return(result_offset);
 323 }
 324