sbin/hammer/ondisk.c

   1 /*
   2  * Copyright (c) 2007 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
  35 #include <sys/diskslice.h>
  36 #include <sys/diskmbr.h>
  37
  38 #include "hammer_util.h"
  39
  40 static void check_volume(struct volume_info *vol);
  41 static void get_buffer_readahead(struct buffer_info *base);
  42 static __inline int readhammervol(struct volume_info *vol);
  43 static __inline int readhammerbuf(struct buffer_info *buf);
  44 static __inline int writehammervol(struct volume_info *vol);
  45 static __inline int writehammerbuf(struct buffer_info *buf);
  46
  47 uuid_t Hammer_FSType;
  48 uuid_t Hammer_FSId;
  49 int UseReadBehind = -4;
  50 int UseReadAhead = 4;
  51 int DebugOpt;
  52
  53 TAILQ_HEAD(volume_list, volume_info);
  54 static struct volume_list VolList = TAILQ_HEAD_INITIALIZER(VolList);
  55 static int valid_hammer_volumes;
  56
  57 static __inline
  58 int
  59 buffer_hash(hammer_off_t zone2_offset)
  60 {
  61         int hi;
  62
  63         hi = (int)(zone2_offset / HAMMER_BUFSIZE) & HAMMER_BUFLISTMASK;
  64         return(hi);
  65 }
  66
  67 static struct buffer_info*
  68 find_buffer(hammer_off_t zone2_offset)
  69 {
  70         struct volume_info *volume;
  71         struct buffer_info *buf;
  72         int hi;
  73
  74         volume = get_volume(HAMMER_VOL_DECODE(zone2_offset));
  75         assert(volume);
  76
  77         hi = buffer_hash(zone2_offset);
  78         TAILQ_FOREACH(buf, &volume->buffer_lists[hi], entry)
  79                 if (buf->zone2_offset == zone2_offset)
  80                         return(buf);
  81         return(NULL);
  82 }
  83
  84 static
  85 struct volume_info *
  86 __alloc_volume(const char *volname, int oflags)
  87 {
  88         struct volume_info *vol;
  89         int i;
  90
  91         vol = calloc(1, sizeof(*vol));
  92         vol->vol_no = -1;
  93         vol->rdonly = (oflags == O_RDONLY);
  94         vol->name = strdup(volname);
  95         vol->fd = open(vol->name, oflags);
  96         if (vol->fd < 0)
  97                 err(1, "alloc_volume: Failed to open %s", vol->name);
  98         check_volume(vol);
  99
 100         vol->ondisk = calloc(1, HAMMER_BUFSIZE);
 101
 102         for (i = 0; i < HAMMER_BUFLISTS; ++i)
 103                 TAILQ_INIT(&vol->buffer_lists[i]);
 104
 105         return(vol);
 106 }
 107
 108 static void
 109 __add_volume(struct volume_info *vol)
 110 {
 111         struct volume_info *scan;
 112         struct stat st1, st2;
 113
 114         if (fstat(vol->fd, &st1) != 0)
 115                 errx(1, "add_volume: %s: Failed to stat", vol->name);
 116
 117         TAILQ_FOREACH(scan, &VolList, entry) {
 118                 if (scan->vol_no == vol->vol_no) {
 119                         errx(1, "add_volume: %s: Duplicate volume number %d "
 120                                 "against %s",
 121                                 vol->name, vol->vol_no, scan->name);
 122                 }
 123                 if (fstat(scan->fd, &st2) != 0) {
 124                         errx(1, "add_volume: %s: Failed to stat %s",
 125                                 vol->name, scan->name);
 126                 }
 127                 if ((st1.st_ino == st2.st_ino) && (st1.st_dev == st2.st_dev)) {
 128                         errx(1, "add_volume: %s: Specified more than once",
 129                                 vol->name);
 130                 }
 131         }
 132
 133         TAILQ_INSERT_TAIL(&VolList, vol, entry);
 134 }
 135
 136 static void
 137 __verify_volume(struct volume_info *vol)
 138 {
 139         hammer_volume_ondisk_t ondisk = vol->ondisk;
 140
 141         if (ondisk->vol_signature != HAMMER_FSBUF_VOLUME) {
 142                 errx(1, "verify_volume: Invalid volume signature %016jx",
 143                         ondisk->vol_signature);
 144         }
 145         if (ondisk->vol_rootvol != HAMMER_ROOT_VOLNO) {
 146                 errx(1, "verify_volume: Invalid root volume# %d",
 147                         ondisk->vol_rootvol);
 148         }
 149         if (bcmp(&Hammer_FSType, &ondisk->vol_fstype, sizeof(Hammer_FSType))) {
 150                 errx(1, "verify_volume: %s: Header does not indicate "
 151                         "that this is a HAMMER volume", vol->name);
 152         }
 153         if (bcmp(&Hammer_FSId, &ondisk->vol_fsid, sizeof(Hammer_FSId))) {
 154                 errx(1, "verify_volume: %s: FSId does not match other volumes!",
 155                         vol->name);
 156         }
 157 }
 158
 159 /*
 160  * Initialize a volume structure and ondisk vol_no field.
 161  */
 162 struct volume_info *
 163 init_volume(const char *filename, int oflags, int32_t vol_no)
 164 {
 165         struct volume_info *vol;
 166
 167         vol = __alloc_volume(filename, oflags);
 168         vol->vol_no = vol->ondisk->vol_no = vol_no;
 169
 170         __add_volume(vol);
 171
 172         return(vol);
 173 }
 174
 175 /*
 176  * Initialize a volume structure and read ondisk volume header.
 177  */
 178 struct volume_info*
 179 load_volume(const char *filename, int oflags, int verify)
 180 {
 181         struct volume_info *vol;
 182         int n;
 183
 184         vol = __alloc_volume(filename, oflags);
 185
 186         n = readhammervol(vol);
 187         if (n == -1) {
 188                 err(1, "load_volume: %s: Read failed at offset 0", vol->name);
 189         }
 190         vol->vol_no = vol->ondisk->vol_no;
 191
 192         if (valid_hammer_volumes++ == 0)
 193                 Hammer_FSId = vol->ondisk->vol_fsid;
 194         if (verify)
 195                 __verify_volume(vol);
 196
 197         __add_volume(vol);
 198
 199         return(vol);
 200 }
 201
 202 /*
 203  * Check basic volume characteristics.
 204  */
 205 static void
 206 check_volume(struct volume_info *vol)
 207 {
 208         struct partinfo pinfo;
 209         struct stat st;
 210
 211         /*
 212          * Get basic information about the volume
 213          */
 214         if (ioctl(vol->fd, DIOCGPART, &pinfo) < 0) {
 215                 /*
 216                  * Allow the formatting of regular files as HAMMER volumes
 217                  */
 218                 if (fstat(vol->fd, &st) < 0)
 219                         err(1, "Unable to stat %s", vol->name);
 220                 vol->size = st.st_size;
 221                 vol->type = "REGFILE";
 222         } else {
 223                 /*
 224                  * When formatting a block device as a HAMMER volume the
 225                  * sector size must be compatible.  HAMMER uses 16384 byte
 226                  * filesystem buffers.
 227                  */
 228                 if (pinfo.reserved_blocks) {
 229                         errx(1, "HAMMER cannot be placed in a partition "
 230                                 "which overlaps the disklabel or MBR");
 231                 }
 232                 if (pinfo.media_blksize > HAMMER_BUFSIZE ||
 233                     HAMMER_BUFSIZE % pinfo.media_blksize) {
 234                         errx(1, "A media sector size of %d is not supported",
 235                              pinfo.media_blksize);
 236                 }
 237
 238                 vol->size = pinfo.media_size;
 239                 vol->device_offset = pinfo.media_offset;
 240                 vol->type = "DEVICE";
 241         }
 242 }
 243
 244 void
 245 assert_volume_offset(struct volume_info *vol)
 246 {
 247         assert(hammer_is_zone_raw_buffer(vol->vol_free_off));
 248         assert(hammer_is_zone_raw_buffer(vol->vol_free_end));
 249         if (vol->vol_free_off >= vol->vol_free_end)
 250                 errx(1, "Ran out of room, filesystem too small");
 251 }
 252
 253 struct volume_info *
 254 get_volume(int32_t vol_no)
 255 {
 256         struct volume_info *vol;
 257
 258         TAILQ_FOREACH(vol, &VolList, entry) {
 259                 if (vol->vol_no == vol_no)
 260                         break;
 261         }
 262
 263         return(vol);
 264 }
 265
 266 struct volume_info *
 267 get_root_volume(void)
 268 {
 269         return(get_volume(HAMMER_ROOT_VOLNO));
 270 }
 271
 272 static hammer_off_t
 273 __blockmap_xlate_to_zone2(hammer_off_t buf_offset)
 274 {
 275         hammer_off_t zone2_offset;
 276         int error = 0;
 277
 278         if (hammer_is_zone_raw_buffer(buf_offset))
 279                 zone2_offset = buf_offset;
 280         else
 281                 zone2_offset = blockmap_lookup(buf_offset, &error);
 282
 283         if (error)
 284                 return(HAMMER_OFF_BAD);
 285         assert(hammer_is_zone_raw_buffer(zone2_offset));
 286
 287         return(zone2_offset);
 288 }
 289
 290 static struct buffer_info *
 291 __alloc_buffer(hammer_off_t zone2_offset, int isnew)
 292 {
 293         struct volume_info *volume;
 294         struct buffer_info *buf;
 295         int hi;
 296
 297         volume = get_volume(HAMMER_VOL_DECODE(zone2_offset));
 298         assert(volume != NULL);
 299
 300         buf = calloc(1, sizeof(*buf));
 301         buf->zone2_offset = zone2_offset;
 302         buf->raw_offset = hammer_xlate_to_phys(volume->ondisk, zone2_offset);
 303         buf->volume = volume;
 304         buf->ondisk = calloc(1, HAMMER_BUFSIZE);
 305
 306         if (isnew <= 0) {
 307                 if (readhammerbuf(buf) == -1) {
 308                         err(1, "Failed to read %s:%016jx at %016jx",
 309                             volume->name,
 310                             (intmax_t)buf->zone2_offset,
 311                             (intmax_t)buf->raw_offset);
 312                 }
 313         }
 314
 315         hi = buffer_hash(zone2_offset);
 316         TAILQ_INSERT_TAIL(&volume->buffer_lists[hi], buf, entry);
 317         hammer_cache_add(&buf->cache);
 318
 319         return(buf);
 320 }
 321
 322 /*
 323  * Acquire the 16KB buffer for specified zone offset.
 324  */
 325 static struct buffer_info *
 326 get_buffer(hammer_off_t buf_offset, int isnew)
 327 {
 328         struct buffer_info *buf;
 329         hammer_off_t zone2_offset;
 330         int dora = 0;
 331
 332         zone2_offset = __blockmap_xlate_to_zone2(buf_offset);
 333         if (zone2_offset == HAMMER_OFF_BAD)
 334                 return(NULL);
 335
 336         zone2_offset &= ~HAMMER_BUFMASK64;
 337         buf = find_buffer(zone2_offset);
 338
 339         if (buf == NULL) {
 340                 buf = __alloc_buffer(zone2_offset, isnew);
 341                 dora = (isnew == 0);
 342         } else {
 343                 assert(isnew != -1);
 344                 hammer_cache_used(&buf->cache);
 345         }
 346         assert(buf->ondisk != NULL);
 347
 348         ++buf->cache.refs;
 349         hammer_cache_flush();
 350
 351         if (isnew > 0) {
 352                 assert(buf->cache.modified == 0);
 353                 bzero(buf->ondisk, HAMMER_BUFSIZE);
 354                 buf->cache.modified = 1;
 355         }
 356         if (dora)
 357                 get_buffer_readahead(buf);
 358         return(buf);
 359 }
 360
 361 static void
 362 get_buffer_readahead(struct buffer_info *base)
 363 {
 364         struct buffer_info *buf;
 365         struct volume_info *vol;
 366         hammer_off_t zone2_offset;
 367         int64_t raw_offset;
 368         int ri = UseReadBehind;
 369         int re = UseReadAhead;
 370
 371         raw_offset = base->raw_offset + ri * HAMMER_BUFSIZE;
 372         vol = base->volume;
 373
 374         while (ri < re) {
 375                 if (raw_offset >= vol->ondisk->vol_buf_end)
 376                         break;
 377                 if (raw_offset < vol->ondisk->vol_buf_beg || ri == 0) {
 378                         ++ri;
 379                         raw_offset += HAMMER_BUFSIZE;
 380                         continue;
 381                 }
 382                 zone2_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no,
 383                         raw_offset - vol->ondisk->vol_buf_beg);
 384                 buf = find_buffer(zone2_offset);
 385                 if (buf == NULL) {
 386                         /* call with -1 to prevent another readahead */
 387                         buf = get_buffer(zone2_offset, -1);
 388                         rel_buffer(buf);
 389                 }
 390                 ++ri;
 391                 raw_offset += HAMMER_BUFSIZE;
 392         }
 393 }
 394
 395 void
 396 rel_buffer(struct buffer_info *buffer)
 397 {
 398         struct volume_info *volume;
 399         int hi;
 400
 401         if (buffer == NULL)
 402                 return;
 403         assert(buffer->cache.refs > 0);
 404         if (--buffer->cache.refs == 0) {
 405                 if (buffer->cache.delete) {
 406                         hi = buffer_hash(buffer->zone2_offset);
 407                         volume = buffer->volume;
 408                         if (buffer->cache.modified)
 409                                 flush_buffer(buffer);
 410                         TAILQ_REMOVE(&volume->buffer_lists[hi], buffer, entry);
 411                         hammer_cache_del(&buffer->cache);
 412                         free(buffer->ondisk);
 413                         free(buffer);
 414                 }
 415         }
 416 }
 417
 418 /*
 419  * Retrieve a pointer to a buffer data given a buffer offset.  The underlying
 420  * bufferp is freed if isnew or the offset is out of range of the cached data.
 421  * If bufferp is freed a referenced buffer is loaded into it.
 422  */
 423 void *
 424 get_buffer_data(hammer_off_t buf_offset, struct buffer_info **bufferp,
 425                 int isnew)
 426 {
 427         hammer_off_t xor;
 428
 429         if (*bufferp != NULL) {
 430                 xor = (*bufferp)->zone2_offset ^ buf_offset;
 431                 if (isnew > 0 || (xor & ~HAMMER_BUFMASK64)) {
 432                         rel_buffer(*bufferp);
 433                         *bufferp = NULL;
 434                 }
 435         }
 436
 437         if (*bufferp == NULL) {
 438                 *bufferp = get_buffer(buf_offset, isnew);
 439                 if (*bufferp == NULL)
 440                         return(NULL);
 441         }
 442
 443         return(((char *)(*bufferp)->ondisk) +
 444                 ((int32_t)buf_offset & HAMMER_BUFMASK));
 445 }
 446
 447 /*
 448  * Allocate HAMMER elements - B-Tree nodes
 449  */
 450 hammer_node_ondisk_t
 451 alloc_btree_node(hammer_off_t *offp, struct buffer_info **data_bufferp)
 452 {
 453         hammer_node_ondisk_t node;
 454
 455         node = alloc_blockmap(HAMMER_ZONE_BTREE_INDEX, sizeof(*node),
 456                               offp, data_bufferp);
 457         bzero(node, sizeof(*node));
 458         return(node);
 459 }
 460
 461 /*
 462  * Allocate HAMMER elements - meta data (inode, direntry, PFS, etc)
 463  */
 464 void *
 465 alloc_meta_element(hammer_off_t *offp, int32_t data_len,
 466                    struct buffer_info **data_bufferp)
 467 {
 468         void *data;
 469
 470         data = alloc_blockmap(HAMMER_ZONE_META_INDEX, data_len,
 471                               offp, data_bufferp);
 472         bzero(data, data_len);
 473         return(data);
 474 }
 475
 476 /*
 477  * Format a new blockmap.  This is mostly a degenerate case because
 478  * all allocations are now actually done from the freemap.
 479  */
 480 void
 481 format_blockmap(struct volume_info *root_vol, int zone, hammer_off_t offset)
 482 {
 483         hammer_blockmap_t blockmap;
 484         hammer_off_t zone_base;
 485
 486         /* Only root volume needs formatting */
 487         assert(root_vol->vol_no == HAMMER_ROOT_VOLNO);
 488
 489         assert(hammer_is_index_record(zone));
 490
 491         blockmap = &root_vol->ondisk->vol0_blockmap[zone];
 492         zone_base = HAMMER_ZONE_ENCODE(zone, offset);
 493
 494         bzero(blockmap, sizeof(*blockmap));
 495         blockmap->phys_offset = 0;
 496         blockmap->first_offset = zone_base;
 497         blockmap->next_offset = zone_base;
 498         blockmap->alloc_offset = HAMMER_ENCODE(zone, 255, -1);
 499         hammer_crc_set_blockmap(blockmap);
 500 }
 501
 502 /*
 503  * Format a new freemap.  Set all layer1 entries to UNAVAIL.  The initialize
 504  * code will load each volume's freemap.
 505  */
 506 void
 507 format_freemap(struct volume_info *root_vol)
 508 {
 509         struct buffer_info *buffer = NULL;
 510         hammer_off_t layer1_offset;
 511         hammer_blockmap_t blockmap;
 512         hammer_blockmap_layer1_t layer1;
 513         int i, isnew;
 514
 515         /* Only root volume needs formatting */
 516         assert(root_vol->vol_no == HAMMER_ROOT_VOLNO);
 517
 518         layer1_offset = bootstrap_bigblock(root_vol);
 519         for (i = 0; i < HAMMER_BIGBLOCK_SIZE; i += sizeof(*layer1)) {
 520                 isnew = ((i % HAMMER_BUFSIZE) == 0);
 521                 layer1 = get_buffer_data(layer1_offset + i, &buffer, isnew);
 522                 bzero(layer1, sizeof(*layer1));
 523                 layer1->phys_offset = HAMMER_BLOCKMAP_UNAVAIL;
 524                 layer1->blocks_free = 0;
 525                 hammer_crc_set_layer1(layer1);
 526         }
 527         assert(i == HAMMER_BIGBLOCK_SIZE);
 528         rel_buffer(buffer);
 529
 530         blockmap = &root_vol->ondisk->vol0_blockmap[HAMMER_ZONE_FREEMAP_INDEX];
 531         bzero(blockmap, sizeof(*blockmap));
 532         blockmap->phys_offset = layer1_offset;
 533         blockmap->first_offset = 0;
 534         blockmap->next_offset = HAMMER_ENCODE_RAW_BUFFER(0, 0);
 535         blockmap->alloc_offset = HAMMER_ENCODE_RAW_BUFFER(255, -1);
 536         hammer_crc_set_blockmap(blockmap);
 537 }
 538
 539 /*
 540  * Load the volume's remaining free space into the freemap.
 541  *
 542  * Returns the number of big-blocks available.
 543  */
 544 int64_t
 545 initialize_freemap(struct volume_info *vol)
 546 {
 547         struct volume_info *root_vol;
 548         struct buffer_info *buffer1 = NULL;
 549         struct buffer_info *buffer2 = NULL;
 550         hammer_blockmap_layer1_t layer1;
 551         hammer_blockmap_layer2_t layer2;
 552         hammer_off_t layer1_offset;
 553         hammer_off_t layer2_offset;
 554         hammer_off_t phys_offset;
 555         hammer_off_t block_offset;
 556         hammer_off_t aligned_vol_free_end;
 557         hammer_blockmap_t freemap;
 558         int64_t count = 0;
 559         int64_t layer1_count = 0;
 560
 561         root_vol = get_root_volume();
 562
 563         assert_volume_offset(vol);
 564         aligned_vol_free_end = HAMMER_BLOCKMAP_LAYER2_DOALIGN(vol->vol_free_end);
 565
 566         printf("initialize freemap volume %d\n", vol->vol_no);
 567
 568         /*
 569          * Initialize the freemap.  First preallocate the big-blocks required
 570          * to implement layer2.   This preallocation is a bootstrap allocation
 571          * using blocks from the target volume.
 572          */
 573         freemap = &root_vol->ondisk->vol0_blockmap[HAMMER_ZONE_FREEMAP_INDEX];
 574
 575         for (phys_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no, 0);
 576              phys_offset < aligned_vol_free_end;
 577              phys_offset += HAMMER_BLOCKMAP_LAYER2) {
 578                 layer1_offset = freemap->phys_offset +
 579                                 HAMMER_BLOCKMAP_LAYER1_OFFSET(phys_offset);
 580                 layer1 = get_buffer_data(layer1_offset, &buffer1, 0);
 581                 if (layer1->phys_offset == HAMMER_BLOCKMAP_UNAVAIL) {
 582                         layer1->phys_offset = bootstrap_bigblock(vol);
 583                         layer1->blocks_free = 0;
 584                         buffer1->cache.modified = 1;
 585                         hammer_crc_set_layer1(layer1);
 586                 }
 587         }
 588
 589         /*
 590          * Now fill everything in.
 591          */
 592         for (phys_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no, 0);
 593              phys_offset < aligned_vol_free_end;
 594              phys_offset += HAMMER_BLOCKMAP_LAYER2) {
 595                 layer1_count = 0;
 596                 layer1_offset = freemap->phys_offset +
 597                                 HAMMER_BLOCKMAP_LAYER1_OFFSET(phys_offset);
 598                 layer1 = get_buffer_data(layer1_offset, &buffer1, 0);
 599                 assert(layer1->phys_offset != HAMMER_BLOCKMAP_UNAVAIL);
 600
 601                 for (block_offset = 0;
 602                      block_offset < HAMMER_BLOCKMAP_LAYER2;
 603                      block_offset += HAMMER_BIGBLOCK_SIZE) {
 604                         layer2_offset = layer1->phys_offset +
 605                                         HAMMER_BLOCKMAP_LAYER2_OFFSET(block_offset);
 606                         layer2 = get_buffer_data(layer2_offset, &buffer2, 0);
 607                         bzero(layer2, sizeof(*layer2));
 608
 609                         if (phys_offset + block_offset < vol->vol_free_off) {
 610                                 /*
 611                                  * Big-blocks already allocated as part
 612                                  * of the freemap bootstrap.
 613                                  */
 614                                 layer2->zone = HAMMER_ZONE_FREEMAP_INDEX;
 615                                 layer2->append_off = HAMMER_BIGBLOCK_SIZE;
 616                                 layer2->bytes_free = 0;
 617                         } else if (phys_offset + block_offset < vol->vol_free_end) {
 618                                 layer2->zone = 0;
 619                                 layer2->append_off = 0;
 620                                 layer2->bytes_free = HAMMER_BIGBLOCK_SIZE;
 621                                 ++count;
 622                                 ++layer1_count;
 623                         } else {
 624                                 layer2->zone = HAMMER_ZONE_UNAVAIL_INDEX;
 625                                 layer2->append_off = HAMMER_BIGBLOCK_SIZE;
 626                                 layer2->bytes_free = 0;
 627                         }
 628                         hammer_crc_set_layer2(layer2);
 629                         buffer2->cache.modified = 1;
 630                 }
 631
 632                 layer1->blocks_free += layer1_count;
 633                 hammer_crc_set_layer1(layer1);
 634                 buffer1->cache.modified = 1;
 635         }
 636
 637         rel_buffer(buffer1);
 638         rel_buffer(buffer2);
 639         return(count);
 640 }
 641
 642 /*
 643  * Returns the number of big-blocks available for filesystem data and undos
 644  * without formatting.
 645  */
 646 int64_t
 647 count_freemap(struct volume_info *vol)
 648 {
 649         hammer_off_t phys_offset;
 650         hammer_off_t vol_free_off;
 651         hammer_off_t aligned_vol_free_end;
 652         int64_t count = 0;
 653
 654         vol_free_off = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no, 0);
 655
 656         assert_volume_offset(vol);
 657         aligned_vol_free_end = HAMMER_BLOCKMAP_LAYER2_DOALIGN(vol->vol_free_end);
 658
 659         if (vol->vol_no == HAMMER_ROOT_VOLNO)
 660                 vol_free_off += HAMMER_BIGBLOCK_SIZE;
 661
 662         for (phys_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no, 0);
 663              phys_offset < aligned_vol_free_end;
 664              phys_offset += HAMMER_BLOCKMAP_LAYER2) {
 665                 vol_free_off += HAMMER_BIGBLOCK_SIZE;
 666         }
 667
 668         for (phys_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no, 0);
 669              phys_offset < aligned_vol_free_end;
 670              phys_offset += HAMMER_BIGBLOCK_SIZE) {
 671                 if (phys_offset < vol_free_off) {
 672                         ;
 673                 } else if (phys_offset < vol->vol_free_end) {
 674                         ++count;
 675                 }
 676         }
 677
 678         return(count);
 679 }
 680
 681 /*
 682  * Format the undomap for the root volume.
 683  */
 684 void
 685 format_undomap(struct volume_info *root_vol, int64_t *undo_buffer_size)
 686 {
 687         hammer_off_t undo_limit;
 688         hammer_blockmap_t blockmap;
 689         hammer_volume_ondisk_t ondisk;
 690         struct buffer_info *buffer = NULL;
 691         hammer_off_t scan;
 692         int n;
 693         int limit_index;
 694         uint32_t seqno;
 695
 696         /* Only root volume needs formatting */
 697         assert(root_vol->vol_no == HAMMER_ROOT_VOLNO);
 698         ondisk = root_vol->ondisk;
 699
 700         /*
 701          * Size the undo buffer in multiples of HAMMER_BIGBLOCK_SIZE,
 702          * up to HAMMER_MAX_UNDO_BIGBLOCKS big-blocks.
 703          * Size to approximately 0.1% of the disk.
 704          *
 705          * The minimum UNDO fifo size is 512MB, or approximately 1% of
 706          * the recommended 50G disk.
 707          *
 708          * Changing this minimum is rather dangerous as complex filesystem
 709          * operations can cause the UNDO FIFO to fill up otherwise.
 710          */
 711         undo_limit = *undo_buffer_size;
 712         if (undo_limit == 0) {
 713                 undo_limit = HAMMER_VOL_BUF_SIZE(ondisk) / 1000;
 714                 if (undo_limit < HAMMER_BIGBLOCK_SIZE * HAMMER_MIN_UNDO_BIGBLOCKS)
 715                         undo_limit = HAMMER_BIGBLOCK_SIZE * HAMMER_MIN_UNDO_BIGBLOCKS;
 716         }
 717         undo_limit = HAMMER_BIGBLOCK_DOALIGN(undo_limit);
 718         if (undo_limit < HAMMER_BIGBLOCK_SIZE)
 719                 undo_limit = HAMMER_BIGBLOCK_SIZE;
 720         if (undo_limit > HAMMER_BIGBLOCK_SIZE * HAMMER_MAX_UNDO_BIGBLOCKS)
 721                 undo_limit = HAMMER_BIGBLOCK_SIZE * HAMMER_MAX_UNDO_BIGBLOCKS;
 722         *undo_buffer_size = undo_limit;
 723
 724         blockmap = &ondisk->vol0_blockmap[HAMMER_ZONE_UNDO_INDEX];
 725         bzero(blockmap, sizeof(*blockmap));
 726         blockmap->phys_offset = HAMMER_BLOCKMAP_UNAVAIL;
 727         blockmap->first_offset = HAMMER_ENCODE_UNDO(0);
 728         blockmap->next_offset = blockmap->first_offset;
 729         blockmap->alloc_offset = HAMMER_ENCODE_UNDO(undo_limit);
 730         hammer_crc_set_blockmap(blockmap);
 731
 732         limit_index = undo_limit / HAMMER_BIGBLOCK_SIZE;
 733         assert(limit_index <= HAMMER_MAX_UNDO_BIGBLOCKS);
 734
 735         for (n = 0; n < limit_index; ++n) {
 736                 ondisk->vol0_undo_array[n] = alloc_undo_bigblock(root_vol);
 737         }
 738         while (n < HAMMER_MAX_UNDO_BIGBLOCKS) {
 739                 ondisk->vol0_undo_array[n++] = HAMMER_BLOCKMAP_UNAVAIL;
 740         }
 741
 742         /*
 743          * Pre-initialize the UNDO blocks (HAMMER version 4+)
 744          */
 745         printf("initializing the undo map (%jd MB)\n",
 746                 (intmax_t)HAMMER_OFF_LONG_ENCODE(blockmap->alloc_offset) /
 747                 (1024 * 1024));
 748
 749         scan = blockmap->first_offset;
 750         seqno = 0;
 751
 752         while (scan < blockmap->alloc_offset) {
 753                 hammer_fifo_head_t head;
 754                 hammer_fifo_tail_t tail;
 755                 int isnew;
 756                 int bytes = HAMMER_UNDO_ALIGN;
 757
 758                 isnew = ((scan & HAMMER_BUFMASK64) == 0);
 759                 head = get_buffer_data(scan, &buffer, isnew);
 760                 buffer->cache.modified = 1;
 761                 tail = (void *)((char *)head + bytes - sizeof(*tail));
 762
 763                 bzero(head, bytes);
 764                 head->hdr_signature = HAMMER_HEAD_SIGNATURE;
 765                 head->hdr_type = HAMMER_HEAD_TYPE_DUMMY;
 766                 head->hdr_size = bytes;
 767                 head->hdr_seq = seqno++;
 768
 769                 tail->tail_signature = HAMMER_TAIL_SIGNATURE;
 770                 tail->tail_type = HAMMER_HEAD_TYPE_DUMMY;
 771                 tail->tail_size = bytes;
 772
 773                 hammer_crc_set_fifo_head(head, bytes);
 774
 775                 scan += bytes;
 776         }
 777         rel_buffer(buffer);
 778 }
 779
 780 const char *zone_labels[] = {
 781         "",             /* 0 */
 782         "raw_volume",   /* 1 */
 783         "raw_buffer",   /* 2 */
 784         "undo",         /* 3 */
 785         "freemap",      /* 4 */
 786         "",             /* 5 */
 787         "",             /* 6 */
 788         "",             /* 7 */
 789         "btree",        /* 8 */
 790         "meta",         /* 9 */
 791         "large_data",   /* 10 */
 792         "small_data",   /* 11 */
 793         "",             /* 12 */
 794         "",             /* 13 */
 795         "",             /* 14 */
 796         "unavail",      /* 15 */
 797 };
 798
 799 void
 800 print_blockmap(const struct volume_info *vol)
 801 {
 802         hammer_blockmap_t blockmap;
 803         hammer_volume_ondisk_t ondisk;
 804         int64_t size, used;
 805         int i;
 806 #define INDENT ""
 807
 808         ondisk = vol->ondisk;
 809         printf(INDENT"vol_label\t%s\n", ondisk->vol_label);
 810         printf(INDENT"vol_count\t%d\n", ondisk->vol_count);
 811         printf(INDENT"vol_bot_beg\t%s\n", sizetostr(ondisk->vol_bot_beg));
 812         printf(INDENT"vol_mem_beg\t%s\n", sizetostr(ondisk->vol_mem_beg));
 813         printf(INDENT"vol_buf_beg\t%s\n", sizetostr(ondisk->vol_buf_beg));
 814         printf(INDENT"vol_buf_end\t%s\n", sizetostr(ondisk->vol_buf_end));
 815         printf(INDENT"vol0_next_tid\t%016jx\n",
 816                (uintmax_t)ondisk->vol0_next_tid);
 817
 818         blockmap = &ondisk->vol0_blockmap[HAMMER_ZONE_UNDO_INDEX];
 819         size = HAMMER_OFF_LONG_ENCODE(blockmap->alloc_offset);
 820         if (blockmap->first_offset <= blockmap->next_offset)
 821                 used = blockmap->next_offset - blockmap->first_offset;
 822         else
 823                 used = blockmap->alloc_offset - blockmap->first_offset +
 824                         HAMMER_OFF_LONG_ENCODE(blockmap->next_offset);
 825         printf(INDENT"undo_size\t%s\n", sizetostr(size));
 826         printf(INDENT"undo_used\t%s\n", sizetostr(used));
 827
 828         printf(INDENT"zone #             "
 829                "phys             first            next             alloc\n");
 830         for (i = 0; i < HAMMER_MAX_ZONES; i++) {
 831                 blockmap = &ondisk->vol0_blockmap[i];
 832                 printf(INDENT"zone %-2d %-10s %016jx %016jx %016jx %016jx\n",
 833                         i, zone_labels[i],
 834                         (uintmax_t)blockmap->phys_offset,
 835                         (uintmax_t)blockmap->first_offset,
 836                         (uintmax_t)blockmap->next_offset,
 837                         (uintmax_t)blockmap->alloc_offset);
 838         }
 839 }
 840
 841 /*
 842  * Flush various tracking structures to disk
 843  */
 844 void
 845 flush_all_volumes(void)
 846 {
 847         struct volume_info *vol;
 848
 849         TAILQ_FOREACH(vol, &VolList, entry)
 850                 flush_volume(vol);
 851 }
 852
 853 void
 854 flush_volume(struct volume_info *volume)
 855 {
 856         struct buffer_info *buffer;
 857         int i;
 858
 859         for (i = 0; i < HAMMER_BUFLISTS; ++i) {
 860                 TAILQ_FOREACH(buffer, &volume->buffer_lists[i], entry)
 861                         flush_buffer(buffer);
 862         }
 863         if (writehammervol(volume) == -1)
 864                 err(1, "Write volume %d (%s)", volume->vol_no, volume->name);
 865 }
 866
 867 void
 868 flush_buffer(struct buffer_info *buffer)
 869 {
 870         struct volume_info *vol;
 871
 872         vol = buffer->volume;
 873         if (writehammerbuf(buffer) == -1)
 874                 err(1, "Write volume %d (%s)", vol->vol_no, vol->name);
 875         buffer->cache.modified = 0;
 876 }
 877
 878 /*
 879  * Core I/O operations
 880  */
 881 static int
 882 __read(struct volume_info *vol, void *data, int64_t offset, int size)
 883 {
 884         ssize_t n;
 885
 886         n = pread(vol->fd, data, size, offset);
 887         if (n != size)
 888                 return(-1);
 889         return(0);
 890 }
 891
 892 static __inline int
 893 readhammervol(struct volume_info *vol)
 894 {
 895         return(__read(vol, vol->ondisk, 0, HAMMER_BUFSIZE));
 896 }
 897
 898 static __inline int
 899 readhammerbuf(struct buffer_info *buf)
 900 {
 901         return(__read(buf->volume, buf->ondisk, buf->raw_offset, HAMMER_BUFSIZE));
 902 }
 903
 904 static int
 905 __write(struct volume_info *vol, const void *data, int64_t offset, int size)
 906 {
 907         ssize_t n;
 908
 909         if (vol->rdonly)
 910                 return(0);
 911
 912         n = pwrite(vol->fd, data, size, offset);
 913         if (n != size)
 914                 return(-1);
 915         return(0);
 916 }
 917
 918 static __inline int
 919 writehammervol(struct volume_info *vol)
 920 {
 921         return(__write(vol, vol->ondisk, 0, HAMMER_BUFSIZE));
 922 }
 923
 924 static __inline int
 925 writehammerbuf(struct buffer_info *buf)
 926 {
 927         return(__write(buf->volume, buf->ondisk, buf->raw_offset, HAMMER_BUFSIZE));
 928 }
 929
 930 int64_t init_boot_area_size(int64_t value, off_t avg_vol_size)
 931 {
 932         if (value == 0) {
 933                 value = HAMMER_BOOT_NOMBYTES;
 934                 while (value > avg_vol_size / HAMMER_MAX_VOLUMES)
 935                         value >>= 1;
 936         }
 937
 938         if (value < HAMMER_BOOT_MINBYTES) {
 939                 value = HAMMER_BOOT_MINBYTES;
 940         } else if (value > HAMMER_BOOT_MAXBYTES) {
 941                 value = HAMMER_BOOT_MAXBYTES;
 942         }
 943
 944         return(value);
 945 }
 946
 947 int64_t init_memory_log_size(int64_t value, off_t avg_vol_size)
 948 {
 949         if (value == 0) {
 950                 value = HAMMER_MEM_NOMBYTES;
 951                 while (value > avg_vol_size / HAMMER_MAX_VOLUMES)
 952                         value >>= 1;
 953         }
 954
 955         if (value < HAMMER_MEM_MINBYTES) {
 956                 value = HAMMER_MEM_MINBYTES;
 957         } else if (value > HAMMER_MEM_MAXBYTES) {
 958                 value = HAMMER_MEM_MAXBYTES;
 959         }
 960
 961         return(value);
 962 }