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         struct hammer_blockmap_layer1 *layer1;
  53         struct hammer_blockmap_layer2 *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_volume(RootVolNo);
  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_volume(RootVolNo);
  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                 root_vol->cache.modified = 1;
  94
  95                 rel_buffer(buffer1);
  96                 rel_buffer(buffer2);
  97                 rel_volume(root_vol);
  98         }
  99
 100         rel_volume(volume);
 101         return(result_offset);
 102 }
 103
 104 /*
 105  * Allocate a chunk of data out of a blockmap.  This is a simplified
 106  * version which uses next_offset as a simple allocation iterator.
 107  */
 108 void *
 109 alloc_blockmap(int zone, int bytes, hammer_off_t *result_offp,
 110                struct buffer_info **bufferp)
 111 {
 112         struct volume_info *volume;
 113         hammer_blockmap_t blockmap;
 114         hammer_blockmap_t freemap;
 115         struct buffer_info *buffer1 = NULL;
 116         struct buffer_info *buffer2 = NULL;
 117         struct hammer_blockmap_layer1 *layer1;
 118         struct hammer_blockmap_layer2 *layer2;
 119         hammer_off_t layer1_offset;
 120         hammer_off_t layer2_offset;
 121         hammer_off_t chunk_offset;
 122         void *ptr;
 123
 124         volume = get_volume(RootVolNo);
 125
 126         blockmap = &volume->ondisk->vol0_blockmap[zone];
 127         freemap = &volume->ondisk->vol0_blockmap[HAMMER_ZONE_FREEMAP_INDEX];
 128         assert(HAMMER_ZONE_DECODE(blockmap->next_offset) == zone);
 129
 130         /*
 131          * Alignment and buffer-boundary issues.  If the allocation would
 132          * cross a buffer boundary we have to skip to the next buffer.
 133          */
 134         bytes = (bytes + 15) & ~15;
 135         assert(bytes > 0 && bytes <= HAMMER_BUFSIZE);  /* not HAMMER_XBUFSIZE */
 136         assert(hammer_is_zone2_mapped_index(zone));
 137
 138 again:
 139         assert(blockmap->next_offset != HAMMER_ZONE_ENCODE(zone + 1, 0));
 140
 141         if ((blockmap->next_offset ^ (blockmap->next_offset + bytes - 1)) &
 142             ~HAMMER_BUFMASK64) {
 143                 volume->cache.modified = 1;
 144                 blockmap->next_offset = (blockmap->next_offset + bytes - 1) &
 145                                         ~HAMMER_BUFMASK64;
 146         }
 147         chunk_offset = blockmap->next_offset & HAMMER_BIGBLOCK_MASK;
 148
 149         /*
 150          * Dive layer 1.
 151          */
 152         layer1_offset = freemap->phys_offset +
 153                         HAMMER_BLOCKMAP_LAYER1_OFFSET(blockmap->next_offset);
 154         layer1 = get_buffer_data(layer1_offset, &buffer1, 0);
 155         assert(!(chunk_offset == 0 && layer1->blocks_free == 0));
 156
 157         if (layer1->phys_offset == HAMMER_BLOCKMAP_UNAVAIL) {
 158                 fprintf(stderr, "alloc_blockmap: ran out of space!\n");
 159                 exit(1);
 160         }
 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: 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                 layer1->layer1_crc = crc32(layer1, HAMMER_LAYER1_CRCSIZE);
 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                 volume->cache.modified = 1;
 188                 blockmap->next_offset = (blockmap->next_offset + HAMMER_BIGBLOCK_SIZE) &
 189                                         ~HAMMER_BIGBLOCK_MASK64;
 190                 goto again;
 191         }
 192
 193         assert(layer2->append_off == chunk_offset);
 194         layer2->bytes_free -= bytes;
 195         *result_offp = blockmap->next_offset;
 196         blockmap->next_offset += bytes;
 197         layer2->append_off = (int)blockmap->next_offset & HAMMER_BIGBLOCK_MASK;
 198         layer2->entry_crc = crc32(layer2, HAMMER_LAYER2_CRCSIZE);
 199
 200         ptr = get_buffer_data(*result_offp, bufferp, 0);
 201         (*bufferp)->cache.modified = 1;
 202
 203         buffer1->cache.modified = 1;
 204         buffer2->cache.modified = 1;
 205         volume->cache.modified = 1;
 206
 207         rel_buffer(buffer1);
 208         rel_buffer(buffer2);
 209         rel_volume(volume);
 210         return(ptr);
 211 }
 212
 213 hammer_off_t
 214 blockmap_lookup(hammer_off_t zone_offset,
 215                 struct hammer_blockmap_layer1 *save_layer1,
 216                 struct hammer_blockmap_layer2 *save_layer2,
 217                 int *errorp)
 218 {
 219         struct volume_info *root_volume = NULL;
 220         hammer_blockmap_t blockmap;
 221         hammer_blockmap_t freemap;
 222         struct hammer_blockmap_layer1 *layer1;
 223         struct hammer_blockmap_layer2 *layer2;
 224         struct buffer_info *buffer1 = NULL;
 225         struct buffer_info *buffer2 = NULL;
 226         hammer_off_t layer1_offset;
 227         hammer_off_t layer2_offset;
 228         hammer_off_t result_offset;
 229         int zone;
 230         int i;
 231         int error = 0;
 232
 233         if (save_layer1)
 234                 bzero(save_layer1, sizeof(*save_layer1));
 235         if (save_layer2)
 236                 bzero(save_layer2, sizeof(*save_layer2));
 237
 238         zone = HAMMER_ZONE_DECODE(zone_offset);
 239
 240         if (zone <= HAMMER_ZONE_RAW_VOLUME_INDEX)
 241                 error = -1;
 242         if (zone >= HAMMER_MAX_ZONES)
 243                 error = -2;
 244         if (RootVolNo < 0)
 245                 error = -3;
 246         if (error) {
 247                 result_offset = HAMMER_OFF_BAD;
 248                 goto done;
 249         }
 250
 251         root_volume = get_volume(RootVolNo);
 252         blockmap = &root_volume->ondisk->vol0_blockmap[zone];
 253
 254         if (zone == HAMMER_ZONE_RAW_BUFFER_INDEX) {
 255                 result_offset = zone_offset;
 256         } else if (zone == HAMMER_ZONE_UNDO_INDEX) {
 257                 i = (zone_offset & HAMMER_OFF_SHORT_MASK) /
 258                     HAMMER_BIGBLOCK_SIZE;
 259                 if (zone_offset >= blockmap->alloc_offset) {
 260                         error = -4;
 261                         result_offset = HAMMER_OFF_BAD;
 262                         goto done;
 263                 }
 264                 result_offset = root_volume->ondisk->vol0_undo_array[i] +
 265                                 (zone_offset & HAMMER_BIGBLOCK_MASK64);
 266         } else {
 267                 result_offset = hammer_xlate_to_zone2(zone_offset);
 268         }
 269
 270         /*
 271          * The blockmap should match the requested zone (else the volume
 272          * header is mashed).
 273          *
 274          * Note that a valid offset can still be returned if AssertOnFailure
 275          * is zero.
 276          */
 277         if (HAMMER_ZONE_FREEMAP_INDEX != zone &&
 278             HAMMER_ZONE_DECODE(blockmap->alloc_offset) != zone) {
 279                 error = -5;
 280                 goto done;
 281         }
 282
 283         /*
 284          * Validate that the big-block is assigned to the zone.  Also
 285          * assign save_layer{1,2}.
 286          */
 287
 288         freemap = &root_volume->ondisk->vol0_blockmap[HAMMER_ZONE_FREEMAP_INDEX];
 289         /*
 290          * Dive layer 1.
 291          */
 292         layer1_offset = freemap->phys_offset +
 293                         HAMMER_BLOCKMAP_LAYER1_OFFSET(result_offset);
 294         layer1 = get_buffer_data(layer1_offset, &buffer1, 0);
 295         if (layer1 == NULL) {
 296                 error = -6;
 297                 goto done;
 298         }
 299         if (layer1->phys_offset == HAMMER_BLOCKMAP_UNAVAIL) {
 300                 error = -7;
 301                 goto done;
 302         }
 303
 304         if (save_layer1)
 305                 *save_layer1 = *layer1;
 306
 307         /*
 308          * Dive layer 2, each entry represents a big-block.
 309          */
 310         layer2_offset = layer1->phys_offset +
 311                         HAMMER_BLOCKMAP_LAYER2_OFFSET(result_offset);
 312         layer2 = get_buffer_data(layer2_offset, &buffer2, 0);
 313
 314         if (layer2 == NULL) {
 315                 error = -8;
 316                 goto done;
 317         }
 318         if (layer2->zone != zone) {
 319                 error = -9;
 320                 goto done;
 321         }
 322         if (save_layer2)
 323                 *save_layer2 = *layer2;
 324
 325 done:
 326         rel_buffer(buffer1);
 327         rel_buffer(buffer2);
 328         rel_volume(root_volume);
 329
 330         if (AssertOnFailure && error != 0)
 331                 errx(1, "blockmap_lookup: error=%d\n", error);
 332         if (errorp)
 333                 *errorp = error;
 334
 335         return(result_offset);
 336 }
 337