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 get_buffer_readahead(struct buffer_info *base);
  41 static void *get_ondisk(hammer_off_t buf_offset, struct buffer_info **bufferp,
  42                         int isnew);
  43 static __inline int readhammervol(struct volume_info *vol);
  44 static __inline int readhammerbuf(struct buffer_info *buf);
  45 static __inline int writehammervol(struct volume_info *vol);
  46 static __inline int writehammerbuf(struct buffer_info *buf);
  47
  48 int DebugOpt;
  49
  50 uuid_t Hammer_FSType;
  51 uuid_t Hammer_FSId;
  52 int     UseReadBehind = -4;
  53 int     UseReadAhead = 4;
  54 int     AssertOnFailure = 1;
  55 struct volume_list VolList = TAILQ_HEAD_INITIALIZER(VolList);
  56 static int valid_hammer_volumes;
  57
  58 static __inline
  59 int
  60 buffer_hash(hammer_off_t buf_offset)
  61 {
  62         int hi;
  63
  64         hi = (int)(buf_offset / HAMMER_BUFSIZE) & HAMMER_BUFLISTMASK;
  65         return(hi);
  66 }
  67
  68 static struct buffer_info*
  69 find_buffer(struct volume_info *volume, hammer_off_t buf_offset)
  70 {
  71         int hi;
  72         struct buffer_info *buf;
  73
  74         hi = buffer_hash(buf_offset);
  75         TAILQ_FOREACH(buf, &volume->buffer_lists[hi], entry)
  76                 if (buf->buf_offset == buf_offset)
  77                         return(buf);
  78         return(NULL);
  79 }
  80
  81 static
  82 struct volume_info *
  83 __alloc_volume(const char *volname, int oflags)
  84 {
  85         struct volume_info *vol;
  86         int i;
  87
  88         vol = malloc(sizeof(*vol));
  89         if (vol == NULL)
  90                 err(1, "alloc_volume");
  91         bzero(vol, sizeof(*vol));
  92
  93         vol->vol_no = -1;
  94         vol->rdonly = (oflags == O_RDONLY);
  95         vol->name = strdup(volname);
  96         vol->fd = open(vol->name, oflags);
  97         if (vol->fd < 0)
  98                 err(1, "alloc_volume: Failed to open %s", vol->name);
  99
 100         vol->size = 0;
 101         vol->device_offset = 0;
 102         vol->type = NULL;
 103
 104         vol->ondisk = malloc(HAMMER_BUFSIZE);
 105         if (vol->ondisk == NULL)
 106                 err(1, "alloc_volume");
 107         bzero(vol->ondisk, HAMMER_BUFSIZE);
 108
 109         for (i = 0; i < HAMMER_BUFLISTS; ++i)
 110                 TAILQ_INIT(&vol->buffer_lists[i]);
 111
 112         return(vol);
 113 }
 114
 115 static void
 116 __add_volume(struct volume_info *vol)
 117 {
 118         struct volume_info *scan;
 119         struct stat st1, st2;
 120
 121         if (fstat(vol->fd, &st1) != 0)
 122                 errx(1, "add_volume: %s: Failed to stat", vol->name);
 123
 124         TAILQ_FOREACH(scan, &VolList, entry) {
 125                 if (scan->vol_no == vol->vol_no) {
 126                         errx(1, "add_volume: %s: Duplicate volume number %d "
 127                                 "against %s",
 128                                 vol->name, vol->vol_no, scan->name);
 129                 }
 130                 if (fstat(scan->fd, &st2) != 0) {
 131                         errx(1, "add_volume: %s: Failed to stat %s",
 132                                 vol->name, scan->name);
 133                 }
 134                 if ((st1.st_ino == st2.st_ino) && (st1.st_dev == st2.st_dev)) {
 135                         errx(1, "add_volume: %s: Specified more than once",
 136                                 vol->name);
 137                 }
 138         }
 139
 140         TAILQ_INSERT_TAIL(&VolList, vol, entry);
 141 }
 142
 143 /*
 144  * Initialize a volume structure and ondisk vol_no field.
 145  */
 146 struct volume_info *
 147 init_volume(int32_t vol_no, const char *filename, int oflags)
 148 {
 149         struct volume_info *vol;
 150
 151         vol = __alloc_volume(filename, oflags);
 152         vol->vol_no = vol->ondisk->vol_no = vol_no;
 153
 154         __add_volume(vol);
 155
 156         return(vol);
 157 }
 158
 159 /*
 160  * Initialize a volume structure and read ondisk volume header.
 161  */
 162 struct volume_info*
 163 load_volume(const char *filename, int oflags)
 164 {
 165         struct volume_info *vol;
 166         struct hammer_volume_ondisk *ondisk;
 167         int n;
 168
 169         vol = __alloc_volume(filename, oflags);
 170
 171         n = readhammervol(vol);
 172         if (n == -1) {
 173                 err(1, "load_volume: %s: Read failed at offset 0", vol->name);
 174         }
 175         ondisk = vol->ondisk;
 176         vol->vol_no = ondisk->vol_no;
 177
 178         if (ondisk->vol_rootvol != HAMMER_ROOT_VOLNO) {
 179                 errx(1, "load_volume: Invalid root volume# %d",
 180                         ondisk->vol_rootvol);
 181         }
 182
 183         if (bcmp(&Hammer_FSType, &ondisk->vol_fstype, sizeof(Hammer_FSType))) {
 184                 errx(1, "load_volume: %s: Header does not indicate "
 185                         "that this is a hammer volume", vol->name);
 186         }
 187
 188         if (valid_hammer_volumes++ == 0) {
 189                 Hammer_FSId = ondisk->vol_fsid;
 190         } else if (bcmp(&Hammer_FSId, &ondisk->vol_fsid, sizeof(Hammer_FSId))) {
 191                 errx(1, "load_volume: %s: FSId does match other volumes!",
 192                         vol->name);
 193         }
 194
 195         __add_volume(vol);
 196
 197         return(vol);
 198 }
 199
 200 /*
 201  * Check basic volume characteristics.
 202  */
 203 void
 204 check_volume(struct volume_info *vol)
 205 {
 206         struct partinfo pinfo;
 207         struct stat st;
 208
 209         /*
 210          * Get basic information about the volume
 211          */
 212         if (ioctl(vol->fd, DIOCGPART, &pinfo) < 0) {
 213                 /*
 214                  * Allow the formatting of regular files as HAMMER volumes
 215                  */
 216                 if (fstat(vol->fd, &st) < 0)
 217                         err(1, "Unable to stat %s", vol->name);
 218                 vol->size = st.st_size;
 219                 vol->type = "REGFILE";
 220         } else {
 221                 /*
 222                  * When formatting a block device as a HAMMER volume the
 223                  * sector size must be compatible.  HAMMER uses 16384 byte
 224                  * filesystem buffers.
 225                  */
 226                 if (pinfo.reserved_blocks) {
 227                         errx(1, "HAMMER cannot be placed in a partition "
 228                                 "which overlaps the disklabel or MBR");
 229                 }
 230                 if (pinfo.media_blksize > HAMMER_BUFSIZE ||
 231                     HAMMER_BUFSIZE % pinfo.media_blksize) {
 232                         errx(1, "A media sector size of %d is not supported",
 233                              pinfo.media_blksize);
 234                 }
 235
 236                 vol->size = pinfo.media_size;
 237                 vol->device_offset = pinfo.media_offset;
 238                 vol->type = "DEVICE";
 239         }
 240 }
 241
 242 struct volume_info *
 243 get_volume(int32_t vol_no)
 244 {
 245         struct volume_info *vol;
 246
 247         TAILQ_FOREACH(vol, &VolList, entry) {
 248                 if (vol->vol_no == vol_no)
 249                         break;
 250         }
 251         if (vol == NULL)
 252                 errx(1, "get_volume: Volume %d does not exist!", vol_no);
 253
 254         /* not added to or removed from hammer cache */
 255         return(vol);
 256 }
 257
 258 struct volume_info *
 259 get_root_volume(void)
 260 {
 261         return(get_volume(HAMMER_ROOT_VOLNO));
 262 }
 263
 264 void
 265 rel_volume(struct volume_info *volume __unused)
 266 {
 267         /* nothing to do */
 268 }
 269
 270 /*
 271  * Acquire the specified buffer.  isnew is -1 only when called
 272  * via get_buffer_readahead() to prevent another readahead.
 273  */
 274 struct buffer_info *
 275 get_buffer(hammer_off_t buf_offset, int isnew)
 276 {
 277         struct buffer_info *buf;
 278         struct volume_info *volume;
 279         int vol_no;
 280         int zone;
 281         int hi;
 282         int dora = 0;
 283
 284         zone = HAMMER_ZONE_DECODE(buf_offset);
 285         if (zone > HAMMER_ZONE_RAW_BUFFER_INDEX) {
 286                 buf_offset = blockmap_lookup(buf_offset, NULL, NULL, NULL);
 287         }
 288         if (buf_offset == HAMMER_OFF_BAD)
 289                 return(NULL);
 290         assert(hammer_is_zone_raw_buffer(buf_offset));
 291
 292         vol_no = HAMMER_VOL_DECODE(buf_offset);
 293         volume = get_volume(vol_no);
 294
 295         buf_offset &= ~HAMMER_BUFMASK64;
 296         buf = find_buffer(volume, buf_offset);
 297
 298         if (buf == NULL) {
 299                 buf = malloc(sizeof(*buf));
 300                 bzero(buf, sizeof(*buf));
 301                 buf->buf_offset = buf_offset;
 302                 buf->raw_offset = hammer_xlate_to_phys(volume->ondisk,
 303                                                         buf_offset);
 304                 buf->volume = volume;
 305                 buf->ondisk = malloc(HAMMER_BUFSIZE);
 306                 if (isnew <= 0) {
 307                         if (readhammerbuf(buf) == -1) {
 308                                 err(1, "get_buffer: %s:%016jx "
 309                                     "Read failed at offset %016jx",
 310                                     volume->name,
 311                                     (intmax_t)buf->buf_offset,
 312                                     (intmax_t)buf->raw_offset);
 313                         }
 314                 }
 315
 316                 hi = buffer_hash(buf_offset);
 317                 TAILQ_INSERT_TAIL(&volume->buffer_lists[hi], buf, entry);
 318                 buf->cache.buffer = buf;
 319                 hammer_cache_add(&buf->cache);
 320                 dora = (isnew == 0);
 321         } else {
 322                 assert(buf->ondisk != NULL);
 323                 assert(isnew != -1);
 324                 hammer_cache_used(&buf->cache);
 325         }
 326
 327         ++buf->cache.refs;
 328         hammer_cache_flush();
 329
 330         if (isnew > 0) {
 331                 assert(buf->cache.modified == 0);
 332                 bzero(buf->ondisk, HAMMER_BUFSIZE);
 333                 buf->cache.modified = 1;
 334         }
 335         if (dora)
 336                 get_buffer_readahead(buf);
 337         return(buf);
 338 }
 339
 340 static void
 341 get_buffer_readahead(struct buffer_info *base)
 342 {
 343         struct buffer_info *buf;
 344         struct volume_info *vol;
 345         hammer_off_t buf_offset;
 346         int64_t raw_offset;
 347         int ri = UseReadBehind;
 348         int re = UseReadAhead;
 349
 350         raw_offset = base->raw_offset + ri * HAMMER_BUFSIZE;
 351         vol = base->volume;
 352
 353         while (ri < re) {
 354                 if (raw_offset >= vol->ondisk->vol_buf_end)
 355                         break;
 356                 if (raw_offset < vol->ondisk->vol_buf_beg || ri == 0) {
 357                         ++ri;
 358                         raw_offset += HAMMER_BUFSIZE;
 359                         continue;
 360                 }
 361                 buf_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no,
 362                         raw_offset - vol->ondisk->vol_buf_beg);
 363                 buf = find_buffer(vol, buf_offset);
 364                 if (buf == NULL) {
 365                         buf = get_buffer(buf_offset, -1);
 366                         rel_buffer(buf);
 367                 }
 368                 ++ri;
 369                 raw_offset += HAMMER_BUFSIZE;
 370         }
 371 }
 372
 373 void
 374 rel_buffer(struct buffer_info *buffer)
 375 {
 376         struct volume_info *volume;
 377         int hi;
 378
 379         if (buffer == NULL)
 380                 return;
 381         assert(buffer->cache.refs > 0);
 382         if (--buffer->cache.refs == 0) {
 383                 if (buffer->cache.delete) {
 384                         hi = buffer_hash(buffer->buf_offset);
 385                         volume = buffer->volume;
 386                         if (buffer->cache.modified)
 387                                 flush_buffer(buffer);
 388                         TAILQ_REMOVE(&volume->buffer_lists[hi], buffer, entry);
 389                         hammer_cache_del(&buffer->cache);
 390                         free(buffer->ondisk);
 391                         free(buffer);
 392                         rel_volume(volume);
 393                 }
 394         }
 395 }
 396
 397 /*
 398  * Retrieve a pointer to a buffer data given a buffer offset.  The underlying
 399  * bufferp is freed if isnew or the offset is out of range of the cached data.
 400  * If bufferp is freed a referenced buffer is loaded into it.
 401  */
 402 void *
 403 get_buffer_data(hammer_off_t buf_offset, struct buffer_info **bufferp,
 404                 int isnew)
 405 {
 406         if (*bufferp != NULL) {
 407                 if (isnew > 0 ||
 408                     (((*bufferp)->buf_offset ^ buf_offset) & ~HAMMER_BUFMASK64)) {
 409                         rel_buffer(*bufferp);
 410                         *bufferp = NULL;
 411                 }
 412         }
 413         return(get_ondisk(buf_offset, bufferp, isnew));
 414 }
 415
 416 /*
 417  * Retrieve a pointer to a B-Tree node given a zone offset.  The underlying
 418  * bufferp is freed if non-NULL and a referenced buffer is loaded into it.
 419  */
 420 hammer_node_ondisk_t
 421 get_node(hammer_off_t node_offset, struct buffer_info **bufferp)
 422 {
 423         if (*bufferp != NULL) {
 424                 rel_buffer(*bufferp);
 425                 *bufferp = NULL;
 426         }
 427         return(get_ondisk(node_offset, bufferp, 0));
 428 }
 429
 430 /*
 431  * Return a pointer to a buffer data given a buffer offset.
 432  * If *bufferp is NULL acquire the buffer otherwise use that buffer.
 433  */
 434 static void *
 435 get_ondisk(hammer_off_t buf_offset, struct buffer_info **bufferp, int isnew)
 436 {
 437         struct buffer_info *buffer;
 438
 439         buffer = *bufferp;
 440         if (buffer == NULL) {
 441                 buffer = *bufferp = get_buffer(buf_offset, isnew);
 442                 if (buffer == NULL)
 443                         return(NULL);
 444         }
 445
 446         return((char *)buffer->ondisk +
 447                 ((int32_t)buf_offset & HAMMER_BUFMASK));
 448 }
 449
 450 /*
 451  * Allocate HAMMER elements - B-Tree nodes
 452  */
 453 void *
 454 alloc_btree_element(hammer_off_t *offp, struct buffer_info **data_bufferp)
 455 {
 456         hammer_node_ondisk_t node;
 457
 458         node = alloc_blockmap(HAMMER_ZONE_BTREE_INDEX, sizeof(*node),
 459                               offp, data_bufferp);
 460         bzero(node, sizeof(*node));
 461         return (node);
 462 }
 463
 464 /*
 465  * Allocate HAMMER elements - meta data (inode, direntry, PFS, etc)
 466  */
 467 void *
 468 alloc_meta_element(hammer_off_t *offp, int32_t data_len,
 469                    struct buffer_info **data_bufferp)
 470 {
 471         void *data;
 472
 473         data = alloc_blockmap(HAMMER_ZONE_META_INDEX, data_len,
 474                               offp, data_bufferp);
 475         bzero(data, data_len);
 476         return (data);
 477 }
 478
 479 /*
 480  * Allocate HAMMER elements - data storage
 481  *
 482  * The only data_len supported by HAMMER userspace for large data zone
 483  * (zone 10) is HAMMER_BUFSIZE which is 16KB.  >16KB data does not fit
 484  * in a buffer allocated by get_buffer().  Also alloc_blockmap() does
 485  * not consider >16KB buffer size.
 486  */
 487 void *
 488 alloc_data_element(hammer_off_t *offp, int32_t data_len,
 489                    struct buffer_info **data_bufferp)
 490 {
 491         void *data;
 492         int zone;
 493
 494         if (data_len == 0)
 495                 return(NULL);
 496
 497         zone = hammer_data_zone_index(data_len);
 498         assert(data_len <= HAMMER_BUFSIZE); /* just one buffer */
 499         assert(zone == HAMMER_ZONE_LARGE_DATA_INDEX ||
 500                zone == HAMMER_ZONE_SMALL_DATA_INDEX);
 501
 502         data = alloc_blockmap(zone, data_len, offp, data_bufferp);
 503         bzero(data, data_len);
 504         return(data);
 505 }
 506
 507 /*
 508  * Format a new blockmap.  This is mostly a degenerate case because
 509  * all allocations are now actually done from the freemap.
 510  */
 511 void
 512 format_blockmap(struct volume_info *root_vol, int zone, hammer_off_t offset)
 513 {
 514         hammer_blockmap_t blockmap;
 515         hammer_off_t zone_base;
 516
 517         /* Only root volume needs formatting */
 518         assert(root_vol->vol_no == HAMMER_ROOT_VOLNO);
 519
 520         assert(hammer_is_zone2_mapped_index(zone));
 521
 522         blockmap = &root_vol->ondisk->vol0_blockmap[zone];
 523         zone_base = HAMMER_ZONE_ENCODE(zone, offset);
 524
 525         bzero(blockmap, sizeof(*blockmap));
 526         blockmap->phys_offset = 0;
 527         blockmap->first_offset = zone_base;
 528         blockmap->next_offset = zone_base;
 529         blockmap->alloc_offset = HAMMER_ENCODE(zone, 255, -1);
 530         blockmap->entry_crc = crc32(blockmap, HAMMER_BLOCKMAP_CRCSIZE);
 531 }
 532
 533 /*
 534  * Format a new freemap.  Set all layer1 entries to UNAVAIL.  The initialize
 535  * code will load each volume's freemap.
 536  */
 537 void
 538 format_freemap(struct volume_info *root_vol)
 539 {
 540         struct buffer_info *buffer = NULL;
 541         hammer_off_t layer1_offset;
 542         hammer_blockmap_t blockmap;
 543         struct hammer_blockmap_layer1 *layer1;
 544         int i, isnew;
 545
 546         /* Only root volume needs formatting */
 547         assert(root_vol->vol_no == HAMMER_ROOT_VOLNO);
 548
 549         layer1_offset = alloc_bigblock(root_vol, HAMMER_ZONE_FREEMAP_INDEX);
 550         for (i = 0; i < HAMMER_BIGBLOCK_SIZE; i += sizeof(*layer1)) {
 551                 isnew = ((i % HAMMER_BUFSIZE) == 0);
 552                 layer1 = get_buffer_data(layer1_offset + i, &buffer, isnew);
 553                 bzero(layer1, sizeof(*layer1));
 554                 layer1->phys_offset = HAMMER_BLOCKMAP_UNAVAIL;
 555                 layer1->blocks_free = 0;
 556                 layer1->layer1_crc = crc32(layer1, HAMMER_LAYER1_CRCSIZE);
 557         }
 558         assert(i == HAMMER_BIGBLOCK_SIZE);
 559         rel_buffer(buffer);
 560
 561         blockmap = &root_vol->ondisk->vol0_blockmap[HAMMER_ZONE_FREEMAP_INDEX];
 562         bzero(blockmap, sizeof(*blockmap));
 563         blockmap->phys_offset = layer1_offset;
 564         blockmap->first_offset = 0;
 565         blockmap->next_offset = HAMMER_ENCODE_RAW_BUFFER(0, 0);
 566         blockmap->alloc_offset = HAMMER_ENCODE_RAW_BUFFER(255, -1);
 567         blockmap->entry_crc = crc32(blockmap, HAMMER_BLOCKMAP_CRCSIZE);
 568 }
 569
 570 /*
 571  * Load the volume's remaining free space into the freemap.
 572  *
 573  * Returns the number of big-blocks available.
 574  */
 575 int64_t
 576 initialize_freemap(struct volume_info *vol)
 577 {
 578         struct volume_info *root_vol;
 579         struct buffer_info *buffer1 = NULL;
 580         struct buffer_info *buffer2 = NULL;
 581         struct hammer_blockmap_layer1 *layer1;
 582         struct hammer_blockmap_layer2 *layer2;
 583         hammer_off_t layer1_offset;
 584         hammer_off_t layer2_offset;
 585         hammer_off_t phys_offset;
 586         hammer_off_t block_offset;
 587         hammer_off_t aligned_vol_free_end;
 588         hammer_blockmap_t freemap;
 589         int64_t count = 0;
 590         int64_t layer1_count = 0;
 591
 592         root_vol = get_root_volume();
 593         aligned_vol_free_end = (vol->vol_free_end + HAMMER_BLOCKMAP_LAYER2_MASK)
 594                                 & ~HAMMER_BLOCKMAP_LAYER2_MASK;
 595
 596         printf("initialize freemap volume %d\n", vol->vol_no);
 597
 598         /*
 599          * Initialize the freemap.  First preallocate the big-blocks required
 600          * to implement layer2.   This preallocation is a bootstrap allocation
 601          * using blocks from the target volume.
 602          */
 603         freemap = &root_vol->ondisk->vol0_blockmap[HAMMER_ZONE_FREEMAP_INDEX];
 604
 605         for (phys_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no, 0);
 606              phys_offset < aligned_vol_free_end;
 607              phys_offset += HAMMER_BLOCKMAP_LAYER2) {
 608                 layer1_offset = freemap->phys_offset +
 609                                 HAMMER_BLOCKMAP_LAYER1_OFFSET(phys_offset);
 610                 layer1 = get_buffer_data(layer1_offset, &buffer1, 0);
 611                 if (layer1->phys_offset == HAMMER_BLOCKMAP_UNAVAIL) {
 612                         layer1->phys_offset = alloc_bigblock(vol,
 613                                                 HAMMER_ZONE_FREEMAP_INDEX);
 614                         layer1->blocks_free = 0;
 615                         buffer1->cache.modified = 1;
 616                         layer1->layer1_crc = crc32(layer1,
 617                                                    HAMMER_LAYER1_CRCSIZE);
 618                 }
 619         }
 620
 621         /*
 622          * Now fill everything in.
 623          */
 624         for (phys_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no, 0);
 625              phys_offset < aligned_vol_free_end;
 626              phys_offset += HAMMER_BLOCKMAP_LAYER2) {
 627                 layer1_count = 0;
 628                 layer1_offset = freemap->phys_offset +
 629                                 HAMMER_BLOCKMAP_LAYER1_OFFSET(phys_offset);
 630                 layer1 = get_buffer_data(layer1_offset, &buffer1, 0);
 631                 assert(layer1->phys_offset != HAMMER_BLOCKMAP_UNAVAIL);
 632
 633                 for (block_offset = 0;
 634                      block_offset < HAMMER_BLOCKMAP_LAYER2;
 635                      block_offset += HAMMER_BIGBLOCK_SIZE) {
 636                         layer2_offset = layer1->phys_offset +
 637                                         HAMMER_BLOCKMAP_LAYER2_OFFSET(block_offset);
 638                         layer2 = get_buffer_data(layer2_offset, &buffer2, 0);
 639                         bzero(layer2, sizeof(*layer2));
 640
 641                         if (phys_offset + block_offset < vol->vol_free_off) {
 642                                 /*
 643                                  * Fixups XXX - big-blocks already allocated as part
 644                                  * of the freemap bootstrap.
 645                                  */
 646                                 layer2->zone = HAMMER_ZONE_FREEMAP_INDEX;
 647                                 layer2->append_off = HAMMER_BIGBLOCK_SIZE;
 648                                 layer2->bytes_free = 0;
 649                         } else if (phys_offset + block_offset < vol->vol_free_end) {
 650                                 layer2->zone = 0;
 651                                 layer2->append_off = 0;
 652                                 layer2->bytes_free = HAMMER_BIGBLOCK_SIZE;
 653                                 ++count;
 654                                 ++layer1_count;
 655                         } else {
 656                                 layer2->zone = HAMMER_ZONE_UNAVAIL_INDEX;
 657                                 layer2->append_off = HAMMER_BIGBLOCK_SIZE;
 658                                 layer2->bytes_free = 0;
 659                         }
 660                         layer2->entry_crc = crc32(layer2, HAMMER_LAYER2_CRCSIZE);
 661                         buffer2->cache.modified = 1;
 662                 }
 663
 664                 layer1->blocks_free += layer1_count;
 665                 layer1->layer1_crc = crc32(layer1, HAMMER_LAYER1_CRCSIZE);
 666                 buffer1->cache.modified = 1;
 667         }
 668
 669         rel_buffer(buffer1);
 670         rel_buffer(buffer2);
 671         rel_volume(root_vol);
 672         return(count);
 673 }
 674
 675 /*
 676  * Returns the number of big-blocks available for filesystem data and undos
 677  * without formatting.
 678  */
 679 int64_t
 680 count_freemap(struct volume_info *vol)
 681 {
 682         hammer_off_t phys_offset;
 683         hammer_off_t vol_free_off;
 684         hammer_off_t aligned_vol_free_end;
 685         int64_t count = 0;
 686
 687         vol_free_off = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no, 0);
 688         aligned_vol_free_end = (vol->vol_free_end + HAMMER_BLOCKMAP_LAYER2_MASK)
 689                                 & ~HAMMER_BLOCKMAP_LAYER2_MASK;
 690
 691         if (vol->vol_no == HAMMER_ROOT_VOLNO)
 692                 vol_free_off += HAMMER_BIGBLOCK_SIZE;
 693
 694         for (phys_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no, 0);
 695              phys_offset < aligned_vol_free_end;
 696              phys_offset += HAMMER_BLOCKMAP_LAYER2) {
 697                 vol_free_off += HAMMER_BIGBLOCK_SIZE;
 698         }
 699
 700         for (phys_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no, 0);
 701              phys_offset < aligned_vol_free_end;
 702              phys_offset += HAMMER_BIGBLOCK_SIZE) {
 703                 if (phys_offset < vol_free_off) {
 704                         ;
 705                 } else if (phys_offset < vol->vol_free_end) {
 706                         ++count;
 707                 }
 708         }
 709
 710         return(count);
 711 }
 712
 713 /*
 714  * Format the undomap for the root volume.
 715  */
 716 void
 717 format_undomap(struct volume_info *root_vol, int64_t *undo_buffer_size)
 718 {
 719         const int undo_zone = HAMMER_ZONE_UNDO_INDEX;
 720         hammer_off_t undo_limit;
 721         hammer_blockmap_t blockmap;
 722         struct hammer_volume_ondisk *ondisk;
 723         struct buffer_info *buffer = NULL;
 724         hammer_off_t scan;
 725         int n;
 726         int limit_index;
 727         uint32_t seqno;
 728
 729         /* Only root volume needs formatting */
 730         assert(root_vol->vol_no == HAMMER_ROOT_VOLNO);
 731         ondisk = root_vol->ondisk;
 732
 733         /*
 734          * Size the undo buffer in multiples of HAMMER_BIGBLOCK_SIZE,
 735          * up to HAMMER_UNDO_LAYER2 big-blocks.  Size to approximately
 736          * 0.1% of the disk.
 737          *
 738          * The minimum UNDO fifo size is 500MB, or approximately 1% of
 739          * the recommended 50G disk.
 740          *
 741          * Changing this minimum is rather dangerous as complex filesystem
 742          * operations can cause the UNDO FIFO to fill up otherwise.
 743          */
 744         undo_limit = *undo_buffer_size;
 745         if (undo_limit == 0) {
 746                 undo_limit = (ondisk->vol_buf_end - ondisk->vol_buf_beg) / 1000;
 747                 if (undo_limit < 500*1024*1024)
 748                         undo_limit = 500*1024*1024;
 749         }
 750         undo_limit = (undo_limit + HAMMER_BIGBLOCK_MASK64) &
 751                      ~HAMMER_BIGBLOCK_MASK64;
 752         if (undo_limit < HAMMER_BIGBLOCK_SIZE)
 753                 undo_limit = HAMMER_BIGBLOCK_SIZE;
 754         if (undo_limit > HAMMER_BIGBLOCK_SIZE * HAMMER_UNDO_LAYER2)
 755                 undo_limit = HAMMER_BIGBLOCK_SIZE * HAMMER_UNDO_LAYER2;
 756         *undo_buffer_size = undo_limit;
 757
 758         blockmap = &ondisk->vol0_blockmap[undo_zone];
 759         bzero(blockmap, sizeof(*blockmap));
 760         blockmap->phys_offset = HAMMER_BLOCKMAP_UNAVAIL;
 761         blockmap->first_offset = HAMMER_ZONE_ENCODE(undo_zone, 0);
 762         blockmap->next_offset = blockmap->first_offset;
 763         blockmap->alloc_offset = HAMMER_ZONE_ENCODE(undo_zone, undo_limit);
 764         blockmap->entry_crc = crc32(blockmap, HAMMER_BLOCKMAP_CRCSIZE);
 765
 766         limit_index = undo_limit / HAMMER_BIGBLOCK_SIZE;
 767         assert(limit_index <= HAMMER_UNDO_LAYER2);
 768
 769         for (n = 0; n < limit_index; ++n) {
 770                 ondisk->vol0_undo_array[n] = alloc_bigblock(root_vol,
 771                                                         HAMMER_ZONE_UNDO_INDEX);
 772         }
 773         while (n < HAMMER_UNDO_LAYER2) {
 774                 ondisk->vol0_undo_array[n++] = HAMMER_BLOCKMAP_UNAVAIL;
 775         }
 776
 777         /*
 778          * Pre-initialize the UNDO blocks (HAMMER version 4+)
 779          */
 780         printf("initializing the undo map (%jd MB)\n",
 781                 (intmax_t)(blockmap->alloc_offset & HAMMER_OFF_LONG_MASK) /
 782                 (1024 * 1024));
 783
 784         scan = blockmap->first_offset;
 785         seqno = 0;
 786
 787         while (scan < blockmap->alloc_offset) {
 788                 hammer_fifo_head_t head;
 789                 hammer_fifo_tail_t tail;
 790                 int isnew;
 791                 int bytes = HAMMER_UNDO_ALIGN;
 792
 793                 isnew = ((scan & HAMMER_BUFMASK64) == 0);
 794                 head = get_buffer_data(scan, &buffer, isnew);
 795                 buffer->cache.modified = 1;
 796                 tail = (void *)((char *)head + bytes - sizeof(*tail));
 797
 798                 bzero(head, bytes);
 799                 head->hdr_signature = HAMMER_HEAD_SIGNATURE;
 800                 head->hdr_type = HAMMER_HEAD_TYPE_DUMMY;
 801                 head->hdr_size = bytes;
 802                 head->hdr_seq = seqno++;
 803
 804                 tail->tail_signature = HAMMER_TAIL_SIGNATURE;
 805                 tail->tail_type = HAMMER_HEAD_TYPE_DUMMY;
 806                 tail->tail_size = bytes;
 807
 808                 head->hdr_crc = crc32(head, HAMMER_FIFO_HEAD_CRCOFF) ^
 809                                 crc32(head + 1, bytes - sizeof(*head));
 810
 811                 scan += bytes;
 812         }
 813         rel_buffer(buffer);
 814 }
 815
 816 /*
 817  * Flush various tracking structures to disk
 818  */
 819 void
 820 flush_all_volumes(void)
 821 {
 822         struct volume_info *vol;
 823
 824         TAILQ_FOREACH(vol, &VolList, entry)
 825                 flush_volume(vol);
 826 }
 827
 828 void
 829 flush_volume(struct volume_info *volume)
 830 {
 831         struct buffer_info *buffer;
 832         int i;
 833
 834         for (i = 0; i < HAMMER_BUFLISTS; ++i) {
 835                 TAILQ_FOREACH(buffer, &volume->buffer_lists[i], entry)
 836                         flush_buffer(buffer);
 837         }
 838         if (writehammervol(volume) == -1)
 839                 err(1, "Write volume %d (%s)", volume->vol_no, volume->name);
 840 }
 841
 842 void
 843 flush_buffer(struct buffer_info *buffer)
 844 {
 845         struct volume_info *vol;
 846
 847         vol = buffer->volume;
 848         if (writehammerbuf(buffer) == -1)
 849                 err(1, "Write volume %d (%s)", vol->vol_no, vol->name);
 850         buffer->cache.modified = 0;
 851 }
 852
 853 /*
 854  * Core I/O operations
 855  */
 856 static int
 857 __read(struct volume_info *vol, void *data, int64_t offset, int size)
 858 {
 859         ssize_t n;
 860
 861         n = pread(vol->fd, data, size, offset);
 862         if (n != size)
 863                 return(-1);
 864         return(0);
 865 }
 866
 867 static __inline int
 868 readhammervol(struct volume_info *vol)
 869 {
 870         return(__read(vol, vol->ondisk, 0, HAMMER_BUFSIZE));
 871 }
 872
 873 static __inline int
 874 readhammerbuf(struct buffer_info *buf)
 875 {
 876         return(__read(buf->volume, buf->ondisk, buf->raw_offset, HAMMER_BUFSIZE));
 877 }
 878
 879 static int
 880 __write(struct volume_info *vol, const void *data, int64_t offset, int size)
 881 {
 882         ssize_t n;
 883
 884         if (vol->rdonly)
 885                 return(0);
 886
 887         n = pwrite(vol->fd, data, size, offset);
 888         if (n != size)
 889                 return(-1);
 890         return(0);
 891 }
 892
 893 static __inline int
 894 writehammervol(struct volume_info *vol)
 895 {
 896         return(__write(vol, vol->ondisk, 0, HAMMER_BUFSIZE));
 897 }
 898
 899 static __inline int
 900 writehammerbuf(struct buffer_info *buf)
 901 {
 902         return(__write(buf->volume, buf->ondisk, buf->raw_offset, HAMMER_BUFSIZE));
 903 }
 904
 905 int64_t init_boot_area_size(int64_t value, off_t avg_vol_size)
 906 {
 907         if (value == 0) {
 908                 value = HAMMER_BOOT_NOMBYTES;
 909                 while (value > avg_vol_size / HAMMER_MAX_VOLUMES)
 910                         value >>= 1;
 911                 if (value < HAMMER_BOOT_MINBYTES)
 912                         value = 0;
 913         } else if (value < HAMMER_BOOT_MINBYTES) {
 914                 value = HAMMER_BOOT_MINBYTES;
 915         }
 916
 917         return(value);
 918 }
 919
 920 int64_t init_mem_area_size(int64_t value, off_t avg_vol_size)
 921 {
 922         if (value == 0) {
 923                 value = HAMMER_MEM_NOMBYTES;
 924                 while (value > avg_vol_size / HAMMER_MAX_VOLUMES)
 925                         value >>= 1;
 926                 if (value < HAMMER_MEM_MINBYTES)
 927                         value = 0;
 928         } else if (value < HAMMER_MEM_MINBYTES) {
 929                 value = HAMMER_MEM_MINBYTES;
 930         }
 931
 932         return(value);
 933 }