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 /*
  40  * Allocate big-blocks using our poor-man's volume->vol_free_off.
  41  *
  42  * If the zone is HAMMER_ZONE_FREEMAP_INDEX we are bootstrapping the freemap
  43  * itself and cannot update it yet.
  44  */
  45 hammer_off_t
  46 alloc_bigblock(struct volume_info *volume, int zone)
  47 {
  48         struct volume_info *root_vol;
  49         hammer_blockmap_t freemap;
  50         struct buffer_info *buffer1 = NULL;
  51         struct buffer_info *buffer2 = NULL;
  52         hammer_blockmap_layer1_t layer1;
  53         hammer_blockmap_layer2_t layer2;
  54         hammer_off_t layer1_offset;
  55         hammer_off_t layer2_offset;
  56         hammer_off_t result_offset;
  57
  58         if (volume == NULL)
  59                 volume = get_root_volume();
  60
  61         result_offset = volume->vol_free_off;
  62         if (result_offset >= volume->vol_free_end)
  63                 errx(1, "alloc_bigblock: Ran out of room, filesystem too small");
  64
  65         volume->vol_free_off += HAMMER_BIGBLOCK_SIZE;
  66
  67         /*
  68          * Update the freemap if not zone4.
  69          */
  70         if (zone != HAMMER_ZONE_FREEMAP_INDEX) {
  71                 root_vol = get_root_volume();
  72                 freemap = &root_vol->ondisk->vol0_blockmap[HAMMER_ZONE_FREEMAP_INDEX];
  73
  74                 layer1_offset = freemap->phys_offset +
  75                                 HAMMER_BLOCKMAP_LAYER1_OFFSET(result_offset);
  76                 layer1 = get_buffer_data(layer1_offset, &buffer1, 0);
  77                 assert(layer1->phys_offset != HAMMER_BLOCKMAP_UNAVAIL);
  78                 --layer1->blocks_free;
  79                 layer1->layer1_crc = crc32(layer1, HAMMER_LAYER1_CRCSIZE);
  80                 buffer1->cache.modified = 1;
  81
  82                 layer2_offset = layer1->phys_offset +
  83                                 HAMMER_BLOCKMAP_LAYER2_OFFSET(result_offset);
  84                 layer2 = get_buffer_data(layer2_offset, &buffer2, 0);
  85                 assert(layer2->zone == 0);
  86                 layer2->zone = zone;
  87                 layer2->append_off = HAMMER_BIGBLOCK_SIZE;
  88                 layer2->bytes_free = 0;
  89                 layer2->entry_crc = crc32(layer2, HAMMER_LAYER2_CRCSIZE);
  90                 buffer2->cache.modified = 1;
  91
  92                 --root_vol->ondisk->vol0_stat_freebigblocks;
  93
  94                 rel_buffer(buffer1);
  95                 rel_buffer(buffer2);
  96         }
  97
  98         return(result_offset);
  99 }
 100
 101 /*
 102  * Allocate a chunk of data out of a blockmap.  This is a simplified
 103  * version which uses next_offset as a simple allocation iterator.
 104  */
 105 void *
 106 alloc_blockmap(int zone, int bytes, hammer_off_t *result_offp,
 107                struct buffer_info **bufferp)
 108 {
 109         struct volume_info *volume;
 110         hammer_blockmap_t blockmap;
 111         hammer_blockmap_t freemap;
 112         struct buffer_info *buffer1 = NULL;
 113         struct buffer_info *buffer2 = NULL;
 114         hammer_blockmap_layer1_t layer1;
 115         hammer_blockmap_layer2_t layer2;
 116         hammer_off_t layer1_offset;
 117         hammer_off_t layer2_offset;
 118         hammer_off_t chunk_offset;
 119         void *ptr;
 120
 121         volume = get_root_volume();
 122
 123         blockmap = &volume->ondisk->vol0_blockmap[zone];
 124         freemap = &volume->ondisk->vol0_blockmap[HAMMER_ZONE_FREEMAP_INDEX];
 125         assert(HAMMER_ZONE_DECODE(blockmap->next_offset) == zone);
 126
 127         /*
 128          * Alignment and buffer-boundary issues.  If the allocation would
 129          * cross a buffer boundary we have to skip to the next buffer.
 130          */
 131         bytes = (bytes + 15) & ~15;
 132         assert(bytes > 0 && bytes <= HAMMER_BUFSIZE);  /* not HAMMER_XBUFSIZE */
 133         assert(hammer_is_zone2_mapped_index(zone));
 134
 135 again:
 136         assert(blockmap->next_offset != HAMMER_ZONE_ENCODE(zone + 1, 0));
 137
 138         if ((blockmap->next_offset ^ (blockmap->next_offset + bytes - 1)) &
 139             ~HAMMER_BUFMASK64) {
 140                 blockmap->next_offset = (blockmap->next_offset + bytes - 1) &
 141                                         ~HAMMER_BUFMASK64;
 142         }
 143         chunk_offset = blockmap->next_offset & HAMMER_BIGBLOCK_MASK;
 144
 145         /*
 146          * Dive layer 1.
 147          */
 148         layer1_offset = freemap->phys_offset +
 149                         HAMMER_BLOCKMAP_LAYER1_OFFSET(blockmap->next_offset);
 150         layer1 = get_buffer_data(layer1_offset, &buffer1, 0);
 151         assert(!(chunk_offset == 0 && layer1->blocks_free == 0));
 152
 153         if (layer1->phys_offset == HAMMER_BLOCKMAP_UNAVAIL) {
 154                 fprintf(stderr, "alloc_blockmap: ran out of space!\n");
 155                 exit(1);
 156         }
 157
 158         /*
 159          * Dive layer 2, each entry represents a big-block.
 160          */
 161         layer2_offset = layer1->phys_offset +
 162                         HAMMER_BLOCKMAP_LAYER2_OFFSET(blockmap->next_offset);
 163         layer2 = get_buffer_data(layer2_offset, &buffer2, 0);
 164
 165         if (layer2->zone == HAMMER_ZONE_UNAVAIL_INDEX) {
 166                 fprintf(stderr, "alloc_blockmap: ran out of space!\n");
 167                 exit(1);
 168         }
 169
 170         /*
 171          * If we are entering a new big-block assign ownership to our
 172          * zone.  If the big-block is owned by another zone skip it.
 173          */
 174         if (layer2->zone == 0) {
 175                 --layer1->blocks_free;
 176                 layer1->layer1_crc = crc32(layer1, HAMMER_LAYER1_CRCSIZE);
 177                 layer2->zone = zone;
 178                 --volume->ondisk->vol0_stat_freebigblocks;
 179                 assert(layer2->bytes_free == HAMMER_BIGBLOCK_SIZE);
 180                 assert(layer2->append_off == 0);
 181         }
 182         if (layer2->zone != zone) {
 183                 blockmap->next_offset = (blockmap->next_offset + HAMMER_BIGBLOCK_SIZE) &
 184                                         ~HAMMER_BIGBLOCK_MASK64;
 185                 goto again;
 186         }
 187
 188         assert(layer2->append_off == chunk_offset);
 189         layer2->bytes_free -= bytes;
 190         *result_offp = blockmap->next_offset;
 191         blockmap->next_offset += bytes;
 192         layer2->append_off = (int)blockmap->next_offset & HAMMER_BIGBLOCK_MASK;
 193         layer2->entry_crc = crc32(layer2, HAMMER_LAYER2_CRCSIZE);
 194
 195         ptr = get_buffer_data(*result_offp, bufferp, 0);
 196         (*bufferp)->cache.modified = 1;
 197
 198         buffer1->cache.modified = 1;
 199         buffer2->cache.modified = 1;
 200
 201         rel_buffer(buffer1);
 202         rel_buffer(buffer2);
 203         return(ptr);
 204 }
 205
 206 hammer_off_t
 207 blockmap_lookup(hammer_off_t zone_offset,
 208                 hammer_blockmap_layer1_t save_layer1,
 209                 hammer_blockmap_layer2_t save_layer2,
 210                 int *errorp)
 211 {
 212         struct volume_info *root_volume = NULL;
 213         hammer_blockmap_t blockmap;
 214         hammer_blockmap_t freemap;
 215         hammer_blockmap_layer1_t layer1;
 216         hammer_blockmap_layer2_t layer2;
 217         struct buffer_info *buffer1 = NULL;
 218         struct buffer_info *buffer2 = NULL;
 219         hammer_off_t layer1_offset;
 220         hammer_off_t layer2_offset;
 221         hammer_off_t result_offset;
 222         int zone;
 223         int i;
 224         int error = 0;
 225
 226         if (save_layer1)
 227                 bzero(save_layer1, sizeof(*save_layer1));
 228         if (save_layer2)
 229                 bzero(save_layer2, sizeof(*save_layer2));
 230
 231         zone = HAMMER_ZONE_DECODE(zone_offset);
 232
 233         if (zone <= HAMMER_ZONE_RAW_VOLUME_INDEX)
 234                 error = -1;
 235         if (zone >= HAMMER_MAX_ZONES)
 236                 error = -2;
 237         if (error) {
 238                 result_offset = HAMMER_OFF_BAD;
 239                 goto done;
 240         }
 241
 242         root_volume = get_root_volume();
 243         blockmap = &root_volume->ondisk->vol0_blockmap[zone];
 244
 245         if (zone == HAMMER_ZONE_RAW_BUFFER_INDEX) {
 246                 result_offset = zone_offset;
 247         } else if (zone == HAMMER_ZONE_UNDO_INDEX) {
 248                 i = (zone_offset & HAMMER_OFF_SHORT_MASK) /
 249                     HAMMER_BIGBLOCK_SIZE;
 250                 if (zone_offset >= blockmap->alloc_offset) {
 251                         error = -3;
 252                         result_offset = HAMMER_OFF_BAD;
 253                         goto done;
 254                 }
 255                 result_offset = root_volume->ondisk->vol0_undo_array[i] +
 256                                 (zone_offset & HAMMER_BIGBLOCK_MASK64);
 257         } else {
 258                 result_offset = hammer_xlate_to_zone2(zone_offset);
 259         }
 260
 261         /*
 262          * The blockmap should match the requested zone (else the volume
 263          * header is mashed).
 264          */
 265         if (HAMMER_ZONE_FREEMAP_INDEX != zone &&
 266             HAMMER_ZONE_DECODE(blockmap->alloc_offset) != zone) {
 267                 error = -4;
 268                 goto done;
 269         }
 270
 271         /*
 272          * Validate that the big-block is assigned to the zone.  Also
 273          * assign save_layer{1,2}.
 274          */
 275
 276         freemap = &root_volume->ondisk->vol0_blockmap[HAMMER_ZONE_FREEMAP_INDEX];
 277         /*
 278          * Dive layer 1.
 279          */
 280         layer1_offset = freemap->phys_offset +
 281                         HAMMER_BLOCKMAP_LAYER1_OFFSET(result_offset);
 282         layer1 = get_buffer_data(layer1_offset, &buffer1, 0);
 283         if (layer1 == NULL) {
 284                 error = -5;
 285                 goto done;
 286         }
 287         if (layer1->phys_offset == HAMMER_BLOCKMAP_UNAVAIL) {
 288                 error = -6;
 289                 goto done;
 290         }
 291
 292         if (save_layer1)
 293                 *save_layer1 = *layer1;
 294
 295         /*
 296          * Dive layer 2, each entry represents a big-block.
 297          */
 298         layer2_offset = layer1->phys_offset +
 299                         HAMMER_BLOCKMAP_LAYER2_OFFSET(result_offset);
 300         layer2 = get_buffer_data(layer2_offset, &buffer2, 0);
 301
 302         if (layer2 == NULL) {
 303                 error = -7;
 304                 goto done;
 305         }
 306         if (layer2->zone != zone) {
 307                 error = -8;
 308                 goto done;
 309         }
 310         if (save_layer2)
 311                 *save_layer2 = *layer2;
 312
 313 done:
 314         rel_buffer(buffer1);
 315         rel_buffer(buffer2);
 316
 317         if (errorp)
 318                 *errorp = error;
 319
 320         return(result_offset);
 321 }
 322