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 int readhammerbuf(struct volume_info *vol, void *data, int64_t offset);
  44 static int writehammerbuf(struct volume_info *vol, const void *data,
  45                         int64_t offset);
  46
  47 int DebugOpt;
  48
  49 uuid_t Hammer_FSType;
  50 uuid_t Hammer_FSId;
  51 int     UseReadBehind = -4;
  52 int     UseReadAhead = 4;
  53 int     AssertOnFailure = 1;
  54 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 buf_offset)
  60 {
  61         int hi;
  62
  63         hi = (int)(buf_offset / HAMMER_BUFSIZE) & HAMMER_BUFLISTMASK;
  64         return(hi);
  65 }
  66
  67 static struct buffer_info*
  68 find_buffer(struct volume_info *volume, hammer_off_t buf_offset)
  69 {
  70         int hi;
  71         struct buffer_info *buf;
  72
  73         hi = buffer_hash(buf_offset);
  74         TAILQ_FOREACH(buf, &volume->buffer_lists[hi], entry)
  75                 if (buf->buf_offset == buf_offset)
  76                         return(buf);
  77         return(NULL);
  78 }
  79
  80 static
  81 struct volume_info *
  82 __alloc_volume(const char *volname, int oflags)
  83 {
  84         struct volume_info *vol;
  85         int i;
  86
  87         vol = malloc(sizeof(*vol));
  88         if (vol == NULL)
  89                 err(1, "alloc_volume");
  90         bzero(vol, sizeof(*vol));
  91
  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
  99         vol->size = 0;
 100         vol->device_offset = 0;
 101         vol->type = NULL;
 102
 103         vol->ondisk = malloc(HAMMER_BUFSIZE);
 104         if (vol->ondisk == NULL)
 105                 err(1, "alloc_volume");
 106         bzero(vol->ondisk, HAMMER_BUFSIZE);
 107
 108         for (i = 0; i < HAMMER_BUFLISTS; ++i)
 109                 TAILQ_INIT(&vol->buffer_lists[i]);
 110
 111         return(vol);
 112 }
 113
 114 static void
 115 __add_volume(struct volume_info *vol)
 116 {
 117         struct volume_info *scan;
 118         struct stat st1, st2;
 119
 120         if (fstat(vol->fd, &st1) != 0)
 121                 errx(1, "add_volume: %s: Failed to stat", vol->name);
 122
 123         TAILQ_FOREACH(scan, &VolList, entry) {
 124                 if (scan->vol_no == vol->vol_no) {
 125                         errx(1, "add_volume: %s: Duplicate volume number %d "
 126                                 "against %s",
 127                                 vol->name, vol->vol_no, scan->name);
 128                 }
 129                 if (fstat(scan->fd, &st2) != 0) {
 130                         errx(1, "add_volume: %s: Failed to stat %s",
 131                                 vol->name, scan->name);
 132                 }
 133                 if ((st1.st_ino == st2.st_ino) && (st1.st_dev == st2.st_dev)) {
 134                         errx(1, "add_volume: %s: Specified more than once",
 135                                 vol->name);
 136                 }
 137         }
 138
 139         TAILQ_INSERT_TAIL(&VolList, vol, entry);
 140 }
 141
 142 /*
 143  * Initialize a volume structure and ondisk vol_no field.
 144  */
 145 struct volume_info *
 146 init_volume(int32_t vol_no, const char *filename, int oflags)
 147 {
 148         struct volume_info *vol;
 149
 150         vol = __alloc_volume(filename, oflags);
 151         vol->vol_no = vol->ondisk->vol_no = vol_no;
 152
 153         __add_volume(vol);
 154
 155         return(vol);
 156 }
 157
 158 /*
 159  * Initialize a volume structure and read ondisk volume header.
 160  */
 161 struct volume_info*
 162 load_volume(const char *filename, int oflags)
 163 {
 164         struct volume_info *vol;
 165         struct hammer_volume_ondisk *ondisk;
 166         int n;
 167
 168         vol = __alloc_volume(filename, oflags);
 169         ondisk = vol->ondisk;
 170
 171         n = readhammerbuf(vol, ondisk, 0);
 172         if (n == -1) {
 173                 err(1, "load_volume: %s: Read failed at offset 0", vol->name);
 174         }
 175         vol->vol_no = ondisk->vol_no;
 176
 177         if (ondisk->vol_rootvol != HAMMER_ROOT_VOLNO) {
 178                 errx(1, "load_volume: Invalid root volume# %d",
 179                         ondisk->vol_rootvol);
 180         }
 181
 182         if (bcmp(&Hammer_FSType, &ondisk->vol_fstype, sizeof(Hammer_FSType))) {
 183                 errx(1, "load_volume: %s: Header does not indicate "
 184                         "that this is a hammer volume", vol->name);
 185         }
 186
 187         if (valid_hammer_volumes++ == 0) {
 188                 Hammer_FSId = ondisk->vol_fsid;
 189         } else if (bcmp(&Hammer_FSId, &ondisk->vol_fsid, sizeof(Hammer_FSId))) {
 190                 errx(1, "load_volume: %s: FSId does match other volumes!",
 191                         vol->name);
 192         }
 193
 194         __add_volume(vol);
 195
 196         return(vol);
 197 }
 198
 199 /*
 200  * Check basic volume characteristics.
 201  */
 202 void
 203 check_volume(struct volume_info *vol)
 204 {
 205         struct partinfo pinfo;
 206         struct stat st;
 207
 208         /*
 209          * Get basic information about the volume
 210          */
 211         if (ioctl(vol->fd, DIOCGPART, &pinfo) < 0) {
 212                 /*
 213                  * Allow the formatting of regular files as HAMMER volumes
 214                  */
 215                 if (fstat(vol->fd, &st) < 0)
 216                         err(1, "Unable to stat %s", vol->name);
 217                 vol->size = st.st_size;
 218                 vol->type = "REGFILE";
 219         } else {
 220                 /*
 221                  * When formatting a block device as a HAMMER volume the
 222                  * sector size must be compatible.  HAMMER uses 16384 byte
 223                  * filesystem buffers.
 224                  */
 225                 if (pinfo.reserved_blocks) {
 226                         errx(1, "HAMMER cannot be placed in a partition "
 227                                 "which overlaps the disklabel or MBR");
 228                 }
 229                 if (pinfo.media_blksize > HAMMER_BUFSIZE ||
 230                     HAMMER_BUFSIZE % pinfo.media_blksize) {
 231                         errx(1, "A media sector size of %d is not supported",
 232                              pinfo.media_blksize);
 233                 }
 234
 235                 vol->size = pinfo.media_size;
 236                 vol->device_offset = pinfo.media_offset;
 237                 vol->type = "DEVICE";
 238         }
 239 }
 240
 241 struct volume_info *
 242 get_volume(int32_t vol_no)
 243 {
 244         struct volume_info *vol;
 245
 246         TAILQ_FOREACH(vol, &VolList, entry) {
 247                 if (vol->vol_no == vol_no)
 248                         break;
 249         }
 250         if (vol == NULL)
 251                 errx(1, "get_volume: Volume %d does not exist!", vol_no);
 252
 253         /* not added to or removed from hammer cache */
 254         return(vol);
 255 }
 256
 257 struct volume_info *
 258 get_root_volume(void)
 259 {
 260         return(get_volume(HAMMER_ROOT_VOLNO));
 261 }
 262
 263 void
 264 rel_volume(struct volume_info *volume __unused)
 265 {
 266         /* nothing to do */
 267 }
 268
 269 /*
 270  * Acquire the specified buffer.  isnew is -1 only when called
 271  * via get_buffer_readahead() to prevent another readahead.
 272  */
 273 struct buffer_info *
 274 get_buffer(hammer_off_t buf_offset, int isnew)
 275 {
 276         struct buffer_info *buf;
 277         struct volume_info *volume;
 278         hammer_off_t orig_offset = buf_offset;
 279         int vol_no;
 280         int zone;
 281         int hi, n;
 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                 if (DebugOpt > 1) {
 302                         fprintf(stderr, "get_buffer: %016jx %016jx at %p\n",
 303                                 (intmax_t)orig_offset, (intmax_t)buf_offset,
 304                                 buf);
 305                 }
 306                 buf->buf_offset = buf_offset;
 307                 buf->raw_offset = hammer_xlate_to_phys(volume->ondisk,
 308                                                         buf_offset);
 309                 buf->volume = volume;
 310                 buf->ondisk = malloc(HAMMER_BUFSIZE);
 311                 if (isnew <= 0) {
 312                         n = readhammerbuf(volume, buf->ondisk, buf->raw_offset);
 313                         if (n == -1) {
 314                                 if (AssertOnFailure)
 315                                         err(1, "get_buffer: %s:%016jx "
 316                                             "Read failed at offset %016jx",
 317                                             volume->name,
 318                                             (intmax_t)buf->buf_offset,
 319                                             (intmax_t)buf->raw_offset);
 320                                 bzero(buf->ondisk, HAMMER_BUFSIZE);
 321                         }
 322                 }
 323
 324                 hi = buffer_hash(buf_offset);
 325                 TAILQ_INSERT_TAIL(&volume->buffer_lists[hi], buf, entry);
 326                 buf->cache.buffer = buf;
 327                 hammer_cache_add(&buf->cache);
 328                 dora = (isnew == 0);
 329         } else {
 330                 if (DebugOpt > 1) {
 331                         fprintf(stderr, "get_buffer: %016jx %016jx at %p *\n",
 332                                 (intmax_t)orig_offset, (intmax_t)buf_offset,
 333                                 buf);
 334                 }
 335                 assert(buf->ondisk != NULL);
 336                 hammer_cache_used(&buf->cache);
 337         }
 338
 339         ++buf->cache.refs;
 340         hammer_cache_flush();
 341
 342         if (isnew > 0) {
 343                 assert(buf->cache.modified == 0);
 344                 bzero(buf->ondisk, HAMMER_BUFSIZE);
 345                 buf->cache.modified = 1;
 346         }
 347         if (dora)
 348                 get_buffer_readahead(buf);
 349         return(buf);
 350 }
 351
 352 static void
 353 get_buffer_readahead(struct buffer_info *base)
 354 {
 355         struct buffer_info *buf;
 356         struct volume_info *vol;
 357         hammer_off_t buf_offset;
 358         int64_t raw_offset;
 359         int ri = UseReadBehind;
 360         int re = UseReadAhead;
 361
 362         raw_offset = base->raw_offset + ri * HAMMER_BUFSIZE;
 363         vol = base->volume;
 364
 365         while (ri < re) {
 366                 if (raw_offset >= vol->ondisk->vol_buf_end)
 367                         break;
 368                 if (raw_offset < vol->ondisk->vol_buf_beg || ri == 0) {
 369                         ++ri;
 370                         raw_offset += HAMMER_BUFSIZE;
 371                         continue;
 372                 }
 373                 buf_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no,
 374                         raw_offset - vol->ondisk->vol_buf_beg);
 375                 buf = find_buffer(vol, buf_offset);
 376                 if (buf == NULL) {
 377                         buf = get_buffer(buf_offset, -1);
 378                         rel_buffer(buf);
 379                 }
 380                 ++ri;
 381                 raw_offset += HAMMER_BUFSIZE;
 382         }
 383 }
 384
 385 void
 386 rel_buffer(struct buffer_info *buffer)
 387 {
 388         struct volume_info *volume;
 389         int hi;
 390
 391         if (buffer == NULL)
 392                 return;
 393         assert(buffer->cache.refs > 0);
 394         if (--buffer->cache.refs == 0) {
 395                 if (buffer->cache.delete) {
 396                         hi = buffer_hash(buffer->buf_offset);
 397                         volume = buffer->volume;
 398                         if (buffer->cache.modified)
 399                                 flush_buffer(buffer);
 400                         TAILQ_REMOVE(&volume->buffer_lists[hi], buffer, entry);
 401                         hammer_cache_del(&buffer->cache);
 402                         free(buffer->ondisk);
 403                         free(buffer);
 404                         rel_volume(volume);
 405                 }
 406         }
 407 }
 408
 409 /*
 410  * Retrieve a pointer to a buffer data given a buffer offset.  The underlying
 411  * bufferp is freed if isnew or the offset is out of range of the cached data.
 412  * If bufferp is freed a referenced buffer is loaded into it.
 413  */
 414 void *
 415 get_buffer_data(hammer_off_t buf_offset, struct buffer_info **bufferp,
 416                 int isnew)
 417 {
 418         if (*bufferp != NULL) {
 419                 if (isnew > 0 ||
 420                     (((*bufferp)->buf_offset ^ buf_offset) & ~HAMMER_BUFMASK64)) {
 421                         rel_buffer(*bufferp);
 422                         *bufferp = NULL;
 423                 }
 424         }
 425         return(get_ondisk(buf_offset, bufferp, isnew));
 426 }
 427
 428 /*
 429  * Retrieve a pointer to a B-Tree node given a zone offset.  The underlying
 430  * bufferp is freed if non-NULL and a referenced buffer is loaded into it.
 431  */
 432 hammer_node_ondisk_t
 433 get_node(hammer_off_t node_offset, struct buffer_info **bufferp)
 434 {
 435         if (*bufferp != NULL) {
 436                 rel_buffer(*bufferp);
 437                 *bufferp = NULL;
 438         }
 439         return(get_ondisk(node_offset, bufferp, 0));
 440 }
 441
 442 /*
 443  * Return a pointer to a buffer data given a buffer offset.
 444  * If *bufferp is NULL acquire the buffer otherwise use that buffer.
 445  */
 446 static void *
 447 get_ondisk(hammer_off_t buf_offset, struct buffer_info **bufferp, int isnew)
 448 {
 449         struct buffer_info *buffer;
 450
 451         buffer = *bufferp;
 452         if (buffer == NULL) {
 453                 buffer = *bufferp = get_buffer(buf_offset, isnew);
 454                 if (buffer == NULL)
 455                         return(NULL);
 456         }
 457
 458         return((char *)buffer->ondisk +
 459                 ((int32_t)buf_offset & HAMMER_BUFMASK));
 460 }
 461
 462 /*
 463  * Allocate HAMMER elements - B-Tree nodse
 464  */
 465 void *
 466 alloc_btree_element(hammer_off_t *offp, struct buffer_info **data_bufferp)
 467 {
 468         hammer_node_ondisk_t node;
 469
 470         node = alloc_blockmap(HAMMER_ZONE_BTREE_INDEX, sizeof(*node),
 471                               offp, data_bufferp);
 472         bzero(node, sizeof(*node));
 473         return (node);
 474 }
 475
 476 /*
 477  * Allocate HAMMER elements - meta data (inode, direntry, PFS, etc)
 478  */
 479 void *
 480 alloc_meta_element(hammer_off_t *offp, int32_t data_len,
 481                    struct buffer_info **data_bufferp)
 482 {
 483         void *data;
 484
 485         data = alloc_blockmap(HAMMER_ZONE_META_INDEX, data_len,
 486                               offp, data_bufferp);
 487         bzero(data, data_len);
 488         return (data);
 489 }
 490
 491 /*
 492  * Allocate HAMMER elements - data storage
 493  *
 494  * The only data_len supported by HAMMER userspace for large data zone
 495  * (zone 10) is HAMMER_BUFSIZE which is 16KB.  >16KB data does not fit
 496  * in a buffer allocated by get_buffer().  Also alloc_blockmap() does
 497  * not consider >16KB buffer size.
 498  */
 499 void *
 500 alloc_data_element(hammer_off_t *offp, int32_t data_len,
 501                    struct buffer_info **data_bufferp)
 502 {
 503         void *data;
 504         int zone;
 505
 506         if (data_len == 0)
 507                 return(NULL);
 508
 509         zone = hammer_data_zone_index(data_len);
 510         assert(data_len <= HAMMER_BUFSIZE); /* just one buffer */
 511         assert(zone == HAMMER_ZONE_LARGE_DATA_INDEX ||
 512                zone == HAMMER_ZONE_SMALL_DATA_INDEX);
 513
 514         data = alloc_blockmap(zone, data_len, offp, data_bufferp);
 515         bzero(data, data_len);
 516         return(data);
 517 }
 518
 519 /*
 520  * Format a new blockmap.  This is mostly a degenerate case because
 521  * all allocations are now actually done from the freemap.
 522  */
 523 void
 524 format_blockmap(struct volume_info *root_vol, int zone, hammer_off_t offset)
 525 {
 526         hammer_blockmap_t blockmap;
 527         hammer_off_t zone_base;
 528
 529         /* Only root volume needs formatting */
 530         assert(root_vol->vol_no == HAMMER_ROOT_VOLNO);
 531
 532         assert(hammer_is_zone2_mapped_index(zone));
 533
 534         blockmap = &root_vol->ondisk->vol0_blockmap[zone];
 535         zone_base = HAMMER_ZONE_ENCODE(zone, offset);
 536
 537         bzero(blockmap, sizeof(*blockmap));
 538         blockmap->phys_offset = 0;
 539         blockmap->first_offset = zone_base;
 540         blockmap->next_offset = zone_base;
 541         blockmap->alloc_offset = HAMMER_ENCODE(zone, 255, -1);
 542         blockmap->entry_crc = crc32(blockmap, HAMMER_BLOCKMAP_CRCSIZE);
 543 }
 544
 545 /*
 546  * Format a new freemap.  Set all layer1 entries to UNAVAIL.  The initialize
 547  * code will load each volume's freemap.
 548  */
 549 void
 550 format_freemap(struct volume_info *root_vol)
 551 {
 552         struct buffer_info *buffer = NULL;
 553         hammer_off_t layer1_offset;
 554         hammer_blockmap_t blockmap;
 555         struct hammer_blockmap_layer1 *layer1;
 556         int i, isnew;
 557
 558         /* Only root volume needs formatting */
 559         assert(root_vol->vol_no == HAMMER_ROOT_VOLNO);
 560
 561         layer1_offset = alloc_bigblock(root_vol, HAMMER_ZONE_FREEMAP_INDEX);
 562         for (i = 0; i < HAMMER_BIGBLOCK_SIZE; i += sizeof(*layer1)) {
 563                 isnew = ((i % HAMMER_BUFSIZE) == 0);
 564                 layer1 = get_buffer_data(layer1_offset + i, &buffer, isnew);
 565                 bzero(layer1, sizeof(*layer1));
 566                 layer1->phys_offset = HAMMER_BLOCKMAP_UNAVAIL;
 567                 layer1->blocks_free = 0;
 568                 layer1->layer1_crc = crc32(layer1, HAMMER_LAYER1_CRCSIZE);
 569         }
 570         assert(i == HAMMER_BIGBLOCK_SIZE);
 571         rel_buffer(buffer);
 572
 573         blockmap = &root_vol->ondisk->vol0_blockmap[HAMMER_ZONE_FREEMAP_INDEX];
 574         bzero(blockmap, sizeof(*blockmap));
 575         blockmap->phys_offset = layer1_offset;
 576         blockmap->first_offset = 0;
 577         blockmap->next_offset = HAMMER_ENCODE_RAW_BUFFER(0, 0);
 578         blockmap->alloc_offset = HAMMER_ENCODE_RAW_BUFFER(255, -1);
 579         blockmap->entry_crc = crc32(blockmap, HAMMER_BLOCKMAP_CRCSIZE);
 580 }
 581
 582 /*
 583  * Load the volume's remaining free space into the freemap.
 584  *
 585  * Returns the number of big-blocks available.
 586  */
 587 int64_t
 588 initialize_freemap(struct volume_info *vol)
 589 {
 590         struct volume_info *root_vol;
 591         struct buffer_info *buffer1 = NULL;
 592         struct buffer_info *buffer2 = NULL;
 593         struct hammer_blockmap_layer1 *layer1;
 594         struct hammer_blockmap_layer2 *layer2;
 595         hammer_off_t layer1_base;
 596         hammer_off_t layer1_offset;
 597         hammer_off_t layer2_offset;
 598         hammer_off_t phys_offset;
 599         hammer_off_t block_offset;
 600         hammer_off_t aligned_vol_free_end;
 601         hammer_blockmap_t freemap;
 602         int64_t count = 0;
 603         int64_t layer1_count = 0;
 604
 605         root_vol = get_root_volume();
 606         aligned_vol_free_end = (vol->vol_free_end + HAMMER_BLOCKMAP_LAYER2_MASK)
 607                                 & ~HAMMER_BLOCKMAP_LAYER2_MASK;
 608
 609         printf("initialize freemap volume %d\n", vol->vol_no);
 610
 611         /*
 612          * Initialize the freemap.  First preallocate the big-blocks required
 613          * to implement layer2.   This preallocation is a bootstrap allocation
 614          * using blocks from the target volume.
 615          */
 616         freemap = &root_vol->ondisk->vol0_blockmap[HAMMER_ZONE_FREEMAP_INDEX];
 617         layer1_base = freemap->phys_offset;
 618
 619         for (phys_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no, 0);
 620              phys_offset < aligned_vol_free_end;
 621              phys_offset += HAMMER_BLOCKMAP_LAYER2) {
 622                 layer1_offset = layer1_base +
 623                                 HAMMER_BLOCKMAP_LAYER1_OFFSET(phys_offset);
 624                 layer1 = get_buffer_data(layer1_offset, &buffer1, 0);
 625                 if (layer1->phys_offset == HAMMER_BLOCKMAP_UNAVAIL) {
 626                         layer1->phys_offset = alloc_bigblock(vol,
 627                                                 HAMMER_ZONE_FREEMAP_INDEX);
 628                         layer1->blocks_free = 0;
 629                         buffer1->cache.modified = 1;
 630                         layer1->layer1_crc = crc32(layer1,
 631                                                    HAMMER_LAYER1_CRCSIZE);
 632                 }
 633         }
 634
 635         /*
 636          * Now fill everything in.
 637          */
 638         for (phys_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no, 0);
 639              phys_offset < aligned_vol_free_end;
 640              phys_offset += HAMMER_BLOCKMAP_LAYER2) {
 641                 layer1_count = 0;
 642                 layer1_offset = layer1_base +
 643                                 HAMMER_BLOCKMAP_LAYER1_OFFSET(phys_offset);
 644                 layer1 = get_buffer_data(layer1_offset, &buffer1, 0);
 645                 assert(layer1->phys_offset != HAMMER_BLOCKMAP_UNAVAIL);
 646
 647                 for (block_offset = 0;
 648                      block_offset < HAMMER_BLOCKMAP_LAYER2;
 649                      block_offset += HAMMER_BIGBLOCK_SIZE) {
 650                         layer2_offset = layer1->phys_offset +
 651                                         HAMMER_BLOCKMAP_LAYER2_OFFSET(block_offset);
 652                         layer2 = get_buffer_data(layer2_offset, &buffer2, 0);
 653                         bzero(layer2, sizeof(*layer2));
 654
 655                         if (phys_offset + block_offset < vol->vol_free_off) {
 656                                 /*
 657                                  * Fixups XXX - big-blocks already allocated as part
 658                                  * of the freemap bootstrap.
 659                                  */
 660                                 layer2->zone = HAMMER_ZONE_FREEMAP_INDEX;
 661                                 layer2->append_off = HAMMER_BIGBLOCK_SIZE;
 662                                 layer2->bytes_free = 0;
 663                         } else if (phys_offset + block_offset < vol->vol_free_end) {
 664                                 layer2->zone = 0;
 665                                 layer2->append_off = 0;
 666                                 layer2->bytes_free = HAMMER_BIGBLOCK_SIZE;
 667                                 ++count;
 668                                 ++layer1_count;
 669                         } else {
 670                                 layer2->zone = HAMMER_ZONE_UNAVAIL_INDEX;
 671                                 layer2->append_off = HAMMER_BIGBLOCK_SIZE;
 672                                 layer2->bytes_free = 0;
 673                         }
 674                         layer2->entry_crc = crc32(layer2, HAMMER_LAYER2_CRCSIZE);
 675                         buffer2->cache.modified = 1;
 676                 }
 677
 678                 layer1->blocks_free += layer1_count;
 679                 layer1->layer1_crc = crc32(layer1, HAMMER_LAYER1_CRCSIZE);
 680                 buffer1->cache.modified = 1;
 681         }
 682
 683         rel_buffer(buffer1);
 684         rel_buffer(buffer2);
 685         rel_volume(root_vol);
 686         return(count);
 687 }
 688
 689 /*
 690  * Returns the number of big-blocks available for filesystem data and undos
 691  * without formatting.
 692  */
 693 int64_t
 694 count_freemap(struct volume_info *vol)
 695 {
 696         hammer_off_t phys_offset;
 697         hammer_off_t vol_free_off;
 698         hammer_off_t aligned_vol_free_end;
 699         int64_t count = 0;
 700
 701         vol_free_off = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no, 0);
 702         aligned_vol_free_end = (vol->vol_free_end + HAMMER_BLOCKMAP_LAYER2_MASK)
 703                                 & ~HAMMER_BLOCKMAP_LAYER2_MASK;
 704
 705         if (vol->vol_no == HAMMER_ROOT_VOLNO)
 706                 vol_free_off += HAMMER_BIGBLOCK_SIZE;
 707
 708         for (phys_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no, 0);
 709              phys_offset < aligned_vol_free_end;
 710              phys_offset += HAMMER_BLOCKMAP_LAYER2) {
 711                 vol_free_off += HAMMER_BIGBLOCK_SIZE;
 712         }
 713
 714         for (phys_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no, 0);
 715              phys_offset < aligned_vol_free_end;
 716              phys_offset += HAMMER_BIGBLOCK_SIZE) {
 717                 if (phys_offset < vol_free_off) {
 718                         ;
 719                 } else if (phys_offset < vol->vol_free_end) {
 720                         ++count;
 721                 }
 722         }
 723
 724         return(count);
 725 }
 726
 727 /*
 728  * Format the undomap for the root volume.
 729  */
 730 void
 731 format_undomap(struct volume_info *root_vol, int64_t *undo_buffer_size)
 732 {
 733         const int undo_zone = HAMMER_ZONE_UNDO_INDEX;
 734         hammer_off_t undo_limit;
 735         hammer_blockmap_t blockmap;
 736         struct hammer_volume_ondisk *ondisk;
 737         struct buffer_info *buffer = NULL;
 738         hammer_off_t scan;
 739         int n;
 740         int limit_index;
 741         uint32_t seqno;
 742
 743         /* Only root volume needs formatting */
 744         assert(root_vol->vol_no == HAMMER_ROOT_VOLNO);
 745         ondisk = root_vol->ondisk;
 746
 747         /*
 748          * Size the undo buffer in multiples of HAMMER_BIGBLOCK_SIZE,
 749          * up to HAMMER_UNDO_LAYER2 big-blocks.  Size to approximately
 750          * 0.1% of the disk.
 751          *
 752          * The minimum UNDO fifo size is 500MB, or approximately 1% of
 753          * the recommended 50G disk.
 754          *
 755          * Changing this minimum is rather dangerous as complex filesystem
 756          * operations can cause the UNDO FIFO to fill up otherwise.
 757          */
 758         undo_limit = *undo_buffer_size;
 759         if (undo_limit == 0) {
 760                 undo_limit = (ondisk->vol_buf_end - ondisk->vol_buf_beg) / 1000;
 761                 if (undo_limit < 500*1024*1024)
 762                         undo_limit = 500*1024*1024;
 763         }
 764         undo_limit = (undo_limit + HAMMER_BIGBLOCK_MASK64) &
 765                      ~HAMMER_BIGBLOCK_MASK64;
 766         if (undo_limit < HAMMER_BIGBLOCK_SIZE)
 767                 undo_limit = HAMMER_BIGBLOCK_SIZE;
 768         if (undo_limit > HAMMER_BIGBLOCK_SIZE * HAMMER_UNDO_LAYER2)
 769                 undo_limit = HAMMER_BIGBLOCK_SIZE * HAMMER_UNDO_LAYER2;
 770         *undo_buffer_size = undo_limit;
 771
 772         blockmap = &ondisk->vol0_blockmap[undo_zone];
 773         bzero(blockmap, sizeof(*blockmap));
 774         blockmap->phys_offset = HAMMER_BLOCKMAP_UNAVAIL;
 775         blockmap->first_offset = HAMMER_ZONE_ENCODE(undo_zone, 0);
 776         blockmap->next_offset = blockmap->first_offset;
 777         blockmap->alloc_offset = HAMMER_ZONE_ENCODE(undo_zone, undo_limit);
 778         blockmap->entry_crc = crc32(blockmap, HAMMER_BLOCKMAP_CRCSIZE);
 779
 780         limit_index = undo_limit / HAMMER_BIGBLOCK_SIZE;
 781         assert(limit_index <= HAMMER_UNDO_LAYER2);
 782
 783         for (n = 0; n < limit_index; ++n) {
 784                 ondisk->vol0_undo_array[n] = alloc_bigblock(root_vol,
 785                                                         HAMMER_ZONE_UNDO_INDEX);
 786         }
 787         while (n < HAMMER_UNDO_LAYER2) {
 788                 ondisk->vol0_undo_array[n++] = HAMMER_BLOCKMAP_UNAVAIL;
 789         }
 790
 791         /*
 792          * Pre-initialize the UNDO blocks (HAMMER version 4+)
 793          */
 794         printf("initializing the undo map (%jd MB)\n",
 795                 (intmax_t)(blockmap->alloc_offset & HAMMER_OFF_LONG_MASK) /
 796                 (1024 * 1024));
 797
 798         scan = blockmap->first_offset;
 799         seqno = 0;
 800
 801         while (scan < blockmap->alloc_offset) {
 802                 hammer_fifo_head_t head;
 803                 hammer_fifo_tail_t tail;
 804                 int isnew;
 805                 int bytes = HAMMER_UNDO_ALIGN;
 806
 807                 isnew = ((scan & HAMMER_BUFMASK64) == 0);
 808                 head = get_buffer_data(scan, &buffer, isnew);
 809                 buffer->cache.modified = 1;
 810                 tail = (void *)((char *)head + bytes - sizeof(*tail));
 811
 812                 bzero(head, bytes);
 813                 head->hdr_signature = HAMMER_HEAD_SIGNATURE;
 814                 head->hdr_type = HAMMER_HEAD_TYPE_DUMMY;
 815                 head->hdr_size = bytes;
 816                 head->hdr_seq = seqno++;
 817
 818                 tail->tail_signature = HAMMER_TAIL_SIGNATURE;
 819                 tail->tail_type = HAMMER_HEAD_TYPE_DUMMY;
 820                 tail->tail_size = bytes;
 821
 822                 head->hdr_crc = crc32(head, HAMMER_FIFO_HEAD_CRCOFF) ^
 823                                 crc32(head + 1, bytes - sizeof(*head));
 824
 825                 scan += bytes;
 826         }
 827         rel_buffer(buffer);
 828 }
 829
 830 /*
 831  * Flush various tracking structures to disk
 832  */
 833 void
 834 flush_all_volumes(void)
 835 {
 836         struct volume_info *vol;
 837
 838         TAILQ_FOREACH(vol, &VolList, entry)
 839                 flush_volume(vol);
 840 }
 841
 842 void
 843 flush_volume(struct volume_info *volume)
 844 {
 845         struct buffer_info *buffer;
 846         int i;
 847
 848         for (i = 0; i < HAMMER_BUFLISTS; ++i) {
 849                 TAILQ_FOREACH(buffer, &volume->buffer_lists[i], entry)
 850                         flush_buffer(buffer);
 851         }
 852         if (writehammerbuf(volume, volume->ondisk, 0) == -1)
 853                 err(1, "Write volume %d (%s)", volume->vol_no, volume->name);
 854 }
 855
 856 void
 857 flush_buffer(struct buffer_info *buffer)
 858 {
 859         struct volume_info *vol;
 860
 861         vol = buffer->volume;
 862         if (writehammerbuf(vol, buffer->ondisk, buffer->raw_offset) == -1)
 863                 err(1, "Write volume %d (%s)", vol->vol_no, vol->name);
 864         buffer->cache.modified = 0;
 865 }
 866
 867 /*
 868  * Core I/O operations
 869  */
 870 static int
 871 readhammerbuf(struct volume_info *vol, void *data, int64_t offset)
 872 {
 873         ssize_t n;
 874
 875         n = pread(vol->fd, data, HAMMER_BUFSIZE, offset);
 876         if (n != HAMMER_BUFSIZE)
 877                 return(-1);
 878         return(0);
 879 }
 880
 881 static int
 882 writehammerbuf(struct volume_info *vol, const void *data, int64_t offset)
 883 {
 884         ssize_t n;
 885
 886         if (vol->rdonly)
 887                 return(0);
 888
 889         n = pwrite(vol->fd, data, HAMMER_BUFSIZE, offset);
 890         if (n != HAMMER_BUFSIZE)
 891                 return(-1);
 892         return(0);
 893 }
 894
 895 int64_t init_boot_area_size(int64_t value, off_t avg_vol_size)
 896 {
 897         if (value == 0) {
 898                 value = HAMMER_BOOT_NOMBYTES;
 899                 while (value > avg_vol_size / HAMMER_MAX_VOLUMES)
 900                         value >>= 1;
 901                 if (value < HAMMER_BOOT_MINBYTES)
 902                         value = 0;
 903         } else if (value < HAMMER_BOOT_MINBYTES) {
 904                 value = HAMMER_BOOT_MINBYTES;
 905         }
 906
 907         return(value);
 908 }
 909
 910 int64_t init_mem_area_size(int64_t value, off_t avg_vol_size)
 911 {
 912         if (value == 0) {
 913                 value = HAMMER_MEM_NOMBYTES;
 914                 while (value > avg_vol_size / HAMMER_MAX_VOLUMES)
 915                         value >>= 1;
 916                 if (value < HAMMER_MEM_MINBYTES)
 917                         value = 0;
 918         } else if (value < HAMMER_MEM_MINBYTES) {
 919                 value = HAMMER_MEM_MINBYTES;
 920         }
 921
 922         return(value);
 923 }