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         if (result_offset >= volume->vol_free_end)
  51                 errx(1, "alloc_bigblock: Ran out of room, filesystem too small");
  52
  53         volume->vol_free_off += HAMMER_BIGBLOCK_SIZE;
  54
  55         return(result_offset);
  56 }
  57
  58 /*
  59  * Allocate a big-block for zone-3 for UNDO/REDO FIFO.
  60  */
  61 hammer_off_t
  62 alloc_undo_bigblock(struct volume_info *volume)
  63 {
  64         hammer_blockmap_t freemap;
  65         struct buffer_info *buffer1 = NULL;
  66         struct buffer_info *buffer2 = NULL;
  67         hammer_blockmap_layer1_t layer1;
  68         hammer_blockmap_layer2_t layer2;
  69         hammer_off_t layer1_offset;
  70         hammer_off_t layer2_offset;
  71         hammer_off_t result_offset;
  72
  73         /* Only root volume needs formatting */
  74         assert(volume->vol_no == HAMMER_ROOT_VOLNO);
  75
  76         result_offset = bootstrap_bigblock(volume);
  77         freemap = &volume->ondisk->vol0_blockmap[HAMMER_ZONE_FREEMAP_INDEX];
  78
  79         /*
  80          * Dive layer 1.
  81          */
  82         layer1_offset = freemap->phys_offset +
  83                         HAMMER_BLOCKMAP_LAYER1_OFFSET(result_offset);
  84         layer1 = get_buffer_data(layer1_offset, &buffer1, 0);
  85         assert(layer1->phys_offset != HAMMER_BLOCKMAP_UNAVAIL);
  86         --layer1->blocks_free;
  87         hammer_crc_set_layer1(layer1);
  88         buffer1->cache.modified = 1;
  89
  90         /*
  91          * Dive layer 2, each entry represents a big-block.
  92          */
  93         layer2_offset = layer1->phys_offset +
  94                         HAMMER_BLOCKMAP_LAYER2_OFFSET(result_offset);
  95         layer2 = get_buffer_data(layer2_offset, &buffer2, 0);
  96         assert(layer2->zone == 0);
  97         layer2->zone = HAMMER_ZONE_UNDO_INDEX;
  98         layer2->append_off = HAMMER_BIGBLOCK_SIZE;
  99         layer2->bytes_free = 0;
 100         hammer_crc_set_layer2(layer2);
 101         buffer2->cache.modified = 1;
 102
 103         --volume->ondisk->vol0_stat_freebigblocks;
 104
 105         rel_buffer(buffer1);
 106         rel_buffer(buffer2);
 107
 108         return(result_offset);
 109 }
 110
 111 /*
 112  * Allocate a chunk of data out of a blockmap.  This is a simplified
 113  * version which uses next_offset as a simple allocation iterator.
 114  */
 115 void *
 116 alloc_blockmap(int zone, int bytes, hammer_off_t *result_offp,
 117                struct buffer_info **bufferp)
 118 {
 119         struct volume_info *volume;
 120         hammer_blockmap_t blockmap;
 121         hammer_blockmap_t freemap;
 122         struct buffer_info *buffer1 = NULL;
 123         struct buffer_info *buffer2 = NULL;
 124         hammer_blockmap_layer1_t layer1;
 125         hammer_blockmap_layer2_t layer2;
 126         hammer_off_t layer1_offset;
 127         hammer_off_t layer2_offset;
 128         hammer_off_t chunk_offset;
 129         void *ptr;
 130
 131         volume = get_root_volume();
 132
 133         blockmap = &volume->ondisk->vol0_blockmap[zone];
 134         freemap = &volume->ondisk->vol0_blockmap[HAMMER_ZONE_FREEMAP_INDEX];
 135         assert(HAMMER_ZONE_DECODE(blockmap->next_offset) == zone);
 136
 137         /*
 138          * Alignment and buffer-boundary issues.  If the allocation would
 139          * cross a buffer boundary we have to skip to the next buffer.
 140          */
 141         bytes = HAMMER_DATA_DOALIGN(bytes);
 142         assert(bytes > 0 && bytes <= HAMMER_BUFSIZE);  /* not HAMMER_XBUFSIZE */
 143         assert(hammer_is_zone2_mapped_index(zone));
 144
 145 again:
 146         assert(blockmap->next_offset != HAMMER_ZONE_ENCODE(zone + 1, 0));
 147
 148         if ((blockmap->next_offset ^ (blockmap->next_offset + bytes - 1)) &
 149             ~HAMMER_BUFMASK64) {
 150                 blockmap->next_offset = (blockmap->next_offset + bytes - 1) &
 151                                         ~HAMMER_BUFMASK64;
 152         }
 153         chunk_offset = blockmap->next_offset & HAMMER_BIGBLOCK_MASK;
 154
 155         /*
 156          * Dive layer 1.
 157          */
 158         layer1_offset = freemap->phys_offset +
 159                         HAMMER_BLOCKMAP_LAYER1_OFFSET(blockmap->next_offset);
 160         layer1 = get_buffer_data(layer1_offset, &buffer1, 0);
 161         assert(!(chunk_offset == 0 && layer1->blocks_free == 0));
 162
 163         if (layer1->phys_offset == HAMMER_BLOCKMAP_UNAVAIL) {
 164                 fprintf(stderr, "alloc_blockmap: ran out of space!\n");
 165                 exit(1);
 166         }
 167
 168         /*
 169          * Dive layer 2, each entry represents a big-block.
 170          */
 171         layer2_offset = layer1->phys_offset +
 172                         HAMMER_BLOCKMAP_LAYER2_OFFSET(blockmap->next_offset);
 173         layer2 = get_buffer_data(layer2_offset, &buffer2, 0);
 174
 175         if (layer2->zone == HAMMER_ZONE_UNAVAIL_INDEX) {
 176                 fprintf(stderr, "alloc_blockmap: ran out of space!\n");
 177                 exit(1);
 178         }
 179
 180         /*
 181          * If we are entering a new big-block assign ownership to our
 182          * zone.  If the big-block is owned by another zone skip it.
 183          */
 184         if (layer2->zone == 0) {
 185                 --layer1->blocks_free;
 186                 hammer_crc_set_layer1(layer1);
 187                 layer2->zone = zone;
 188                 --volume->ondisk->vol0_stat_freebigblocks;
 189                 assert(layer2->bytes_free == HAMMER_BIGBLOCK_SIZE);
 190                 assert(layer2->append_off == 0);
 191         }
 192         if (layer2->zone != zone) {
 193                 blockmap->next_offset = (blockmap->next_offset + HAMMER_BIGBLOCK_SIZE) &
 194                                         ~HAMMER_BIGBLOCK_MASK64;
 195                 goto again;
 196         }
 197
 198         assert(layer2->append_off == chunk_offset);
 199         layer2->bytes_free -= bytes;
 200         *result_offp = blockmap->next_offset;
 201         blockmap->next_offset += bytes;
 202         layer2->append_off = (int)blockmap->next_offset & HAMMER_BIGBLOCK_MASK;
 203         hammer_crc_set_layer2(layer2);
 204
 205         ptr = get_buffer_data(*result_offp, bufferp, 0);
 206         (*bufferp)->cache.modified = 1;
 207
 208         buffer1->cache.modified = 1;
 209         buffer2->cache.modified = 1;
 210
 211         rel_buffer(buffer1);
 212         rel_buffer(buffer2);
 213         return(ptr);
 214 }
 215
 216 hammer_off_t
 217 blockmap_lookup(hammer_off_t zone_offset,
 218                 hammer_blockmap_layer1_t save_layer1,
 219                 hammer_blockmap_layer2_t save_layer2,
 220                 int *errorp)
 221 {
 222         struct volume_info *root_volume = NULL;
 223         hammer_blockmap_t blockmap;
 224         hammer_blockmap_t freemap;
 225         hammer_blockmap_layer1_t layer1;
 226         hammer_blockmap_layer2_t layer2;
 227         struct buffer_info *buffer1 = NULL;
 228         struct buffer_info *buffer2 = NULL;
 229         hammer_off_t layer1_offset;
 230         hammer_off_t layer2_offset;
 231         hammer_off_t result_offset;
 232         int zone;
 233         int i;
 234         int error = 0;
 235
 236         if (save_layer1)
 237                 bzero(save_layer1, sizeof(*save_layer1));
 238         if (save_layer2)
 239                 bzero(save_layer2, sizeof(*save_layer2));
 240
 241         zone = HAMMER_ZONE_DECODE(zone_offset);
 242
 243         if (zone <= HAMMER_ZONE_RAW_VOLUME_INDEX)
 244                 error = -1;
 245         if (zone >= HAMMER_MAX_ZONES)
 246                 error = -2;
 247         if (error) {
 248                 result_offset = HAMMER_OFF_BAD;
 249                 goto done;
 250         }
 251
 252         root_volume = get_root_volume();
 253         blockmap = &root_volume->ondisk->vol0_blockmap[zone];
 254
 255         if (zone == HAMMER_ZONE_RAW_BUFFER_INDEX) {
 256                 result_offset = zone_offset;
 257         } else if (zone == HAMMER_ZONE_UNDO_INDEX) {
 258                 i = HAMMER_OFF_SHORT_ENCODE(zone_offset) / HAMMER_BIGBLOCK_SIZE;
 259                 if (zone_offset >= blockmap->alloc_offset) {
 260                         error = -3;
 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         if (HAMMER_ZONE_FREEMAP_INDEX != zone &&
 275             HAMMER_ZONE_DECODE(blockmap->alloc_offset) != zone) {
 276                 error = -4;
 277                 goto done;
 278         }
 279
 280         /*
 281          * Validate that the big-block is assigned to the zone.  Also
 282          * assign save_layer{1,2}.
 283          */
 284
 285         freemap = &root_volume->ondisk->vol0_blockmap[HAMMER_ZONE_FREEMAP_INDEX];
 286         /*
 287          * Dive layer 1.
 288          */
 289         layer1_offset = freemap->phys_offset +
 290                         HAMMER_BLOCKMAP_LAYER1_OFFSET(result_offset);
 291         layer1 = get_buffer_data(layer1_offset, &buffer1, 0);
 292         if (layer1 == NULL) {
 293                 error = -5;
 294                 goto done;
 295         }
 296         if (layer1->phys_offset == HAMMER_BLOCKMAP_UNAVAIL) {
 297                 error = -6;
 298                 goto done;
 299         }
 300
 301         if (save_layer1)
 302                 *save_layer1 = *layer1;
 303
 304         /*
 305          * Dive layer 2, each entry represents a big-block.
 306          */
 307         layer2_offset = layer1->phys_offset +
 308                         HAMMER_BLOCKMAP_LAYER2_OFFSET(result_offset);
 309         layer2 = get_buffer_data(layer2_offset, &buffer2, 0);
 310
 311         if (layer2 == NULL) {
 312                 error = -7;
 313                 goto done;
 314         }
 315         if (layer2->zone != zone) {
 316                 error = -8;
 317                 goto done;
 318         }
 319         if (save_layer2)
 320                 *save_layer2 = *layer2;
 321
 322 done:
 323         rel_buffer(buffer1);
 324         rel_buffer(buffer2);
 325
 326         if (errorp)
 327                 *errorp = error;
 328
 329         return(result_offset);
 330 }
 331