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         hammer_off_t orig_offset = buf_offset;
 280         int vol_no;
 281         int zone;
 282         int hi, n;
 283         int dora = 0;
 284
 285         zone = HAMMER_ZONE_DECODE(buf_offset);
 286         if (zone > HAMMER_ZONE_RAW_BUFFER_INDEX) {
 287                 buf_offset = blockmap_lookup(buf_offset, NULL, NULL, NULL);
 288         }
 289         if (buf_offset == HAMMER_OFF_BAD)
 290                 return(NULL);
 291         assert(hammer_is_zone_raw_buffer(buf_offset));
 292
 293         vol_no = HAMMER_VOL_DECODE(buf_offset);
 294         volume = get_volume(vol_no);
 295
 296         buf_offset &= ~HAMMER_BUFMASK64;
 297         buf = find_buffer(volume, buf_offset);
 298
 299         if (buf == NULL) {
 300                 buf = malloc(sizeof(*buf));
 301                 bzero(buf, sizeof(*buf));
 302                 if (DebugOpt > 1) {
 303                         fprintf(stderr, "get_buffer: %016jx %016jx at %p\n",
 304                                 (intmax_t)orig_offset, (intmax_t)buf_offset,
 305                                 buf);
 306                 }
 307                 buf->buf_offset = buf_offset;
 308                 buf->raw_offset = hammer_xlate_to_phys(volume->ondisk,
 309                                                         buf_offset);
 310                 buf->volume = volume;
 311                 buf->ondisk = malloc(HAMMER_BUFSIZE);
 312                 if (isnew <= 0) {
 313                         n = readhammerbuf(buf);
 314                         if (n == -1) {
 315                                 if (AssertOnFailure)
 316                                         err(1, "get_buffer: %s:%016jx "
 317                                             "Read failed at offset %016jx",
 318                                             volume->name,
 319                                             (intmax_t)buf->buf_offset,
 320                                             (intmax_t)buf->raw_offset);
 321                                 bzero(buf->ondisk, HAMMER_BUFSIZE);
 322                         }
 323                 }
 324
 325                 hi = buffer_hash(buf_offset);
 326                 TAILQ_INSERT_TAIL(&volume->buffer_lists[hi], buf, entry);
 327                 buf->cache.buffer = buf;
 328                 hammer_cache_add(&buf->cache);
 329                 dora = (isnew == 0);
 330         } else {
 331                 if (DebugOpt > 1) {
 332                         fprintf(stderr, "get_buffer: %016jx %016jx at %p *\n",
 333                                 (intmax_t)orig_offset, (intmax_t)buf_offset,
 334                                 buf);
 335                 }
 336                 assert(buf->ondisk != NULL);
 337                 assert(isnew != -1);
 338                 hammer_cache_used(&buf->cache);
 339         }
 340
 341         ++buf->cache.refs;
 342         hammer_cache_flush();
 343
 344         if (isnew > 0) {
 345                 assert(buf->cache.modified == 0);
 346                 bzero(buf->ondisk, HAMMER_BUFSIZE);
 347                 buf->cache.modified = 1;
 348         }
 349         if (dora)
 350                 get_buffer_readahead(buf);
 351         return(buf);
 352 }
 353
 354 static void
 355 get_buffer_readahead(struct buffer_info *base)
 356 {
 357         struct buffer_info *buf;
 358         struct volume_info *vol;
 359         hammer_off_t buf_offset;
 360         int64_t raw_offset;
 361         int ri = UseReadBehind;
 362         int re = UseReadAhead;
 363
 364         raw_offset = base->raw_offset + ri * HAMMER_BUFSIZE;
 365         vol = base->volume;
 366
 367         while (ri < re) {
 368                 if (raw_offset >= vol->ondisk->vol_buf_end)
 369                         break;
 370                 if (raw_offset < vol->ondisk->vol_buf_beg || ri == 0) {
 371                         ++ri;
 372                         raw_offset += HAMMER_BUFSIZE;
 373                         continue;
 374                 }
 375                 buf_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no,
 376                         raw_offset - vol->ondisk->vol_buf_beg);
 377                 buf = find_buffer(vol, buf_offset);
 378                 if (buf == NULL) {
 379                         buf = get_buffer(buf_offset, -1);
 380                         rel_buffer(buf);
 381                 }
 382                 ++ri;
 383                 raw_offset += HAMMER_BUFSIZE;
 384         }
 385 }
 386
 387 void
 388 rel_buffer(struct buffer_info *buffer)
 389 {
 390         struct volume_info *volume;
 391         int hi;
 392
 393         if (buffer == NULL)
 394                 return;
 395         assert(buffer->cache.refs > 0);
 396         if (--buffer->cache.refs == 0) {
 397                 if (buffer->cache.delete) {
 398                         hi = buffer_hash(buffer->buf_offset);
 399                         volume = buffer->volume;
 400                         if (buffer->cache.modified)
 401                                 flush_buffer(buffer);
 402                         TAILQ_REMOVE(&volume->buffer_lists[hi], buffer, entry);
 403                         hammer_cache_del(&buffer->cache);
 404                         free(buffer->ondisk);
 405                         free(buffer);
 406                         rel_volume(volume);
 407                 }
 408         }
 409 }
 410
 411 /*
 412  * Retrieve a pointer to a buffer data given a buffer offset.  The underlying
 413  * bufferp is freed if isnew or the offset is out of range of the cached data.
 414  * If bufferp is freed a referenced buffer is loaded into it.
 415  */
 416 void *
 417 get_buffer_data(hammer_off_t buf_offset, struct buffer_info **bufferp,
 418                 int isnew)
 419 {
 420         if (*bufferp != NULL) {
 421                 if (isnew > 0 ||
 422                     (((*bufferp)->buf_offset ^ buf_offset) & ~HAMMER_BUFMASK64)) {
 423                         rel_buffer(*bufferp);
 424                         *bufferp = NULL;
 425                 }
 426         }
 427         return(get_ondisk(buf_offset, bufferp, isnew));
 428 }
 429
 430 /*
 431  * Retrieve a pointer to a B-Tree node given a zone offset.  The underlying
 432  * bufferp is freed if non-NULL and a referenced buffer is loaded into it.
 433  */
 434 hammer_node_ondisk_t
 435 get_node(hammer_off_t node_offset, struct buffer_info **bufferp)
 436 {
 437         if (*bufferp != NULL) {
 438                 rel_buffer(*bufferp);
 439                 *bufferp = NULL;
 440         }
 441         return(get_ondisk(node_offset, bufferp, 0));
 442 }
 443
 444 /*
 445  * Return a pointer to a buffer data given a buffer offset.
 446  * If *bufferp is NULL acquire the buffer otherwise use that buffer.
 447  */
 448 static void *
 449 get_ondisk(hammer_off_t buf_offset, struct buffer_info **bufferp, int isnew)
 450 {
 451         struct buffer_info *buffer;
 452
 453         buffer = *bufferp;
 454         if (buffer == NULL) {
 455                 buffer = *bufferp = get_buffer(buf_offset, isnew);
 456                 if (buffer == NULL)
 457                         return(NULL);
 458         }
 459
 460         return((char *)buffer->ondisk +
 461                 ((int32_t)buf_offset & HAMMER_BUFMASK));
 462 }
 463
 464 /*
 465  * Allocate HAMMER elements - B-Tree nodes
 466  */
 467 void *
 468 alloc_btree_element(hammer_off_t *offp, struct buffer_info **data_bufferp)
 469 {
 470         hammer_node_ondisk_t node;
 471
 472         node = alloc_blockmap(HAMMER_ZONE_BTREE_INDEX, sizeof(*node),
 473                               offp, data_bufferp);
 474         bzero(node, sizeof(*node));
 475         return (node);
 476 }
 477
 478 /*
 479  * Allocate HAMMER elements - meta data (inode, direntry, PFS, etc)
 480  */
 481 void *
 482 alloc_meta_element(hammer_off_t *offp, int32_t data_len,
 483                    struct buffer_info **data_bufferp)
 484 {
 485         void *data;
 486
 487         data = alloc_blockmap(HAMMER_ZONE_META_INDEX, data_len,
 488                               offp, data_bufferp);
 489         bzero(data, data_len);
 490         return (data);
 491 }
 492
 493 /*
 494  * Allocate HAMMER elements - data storage
 495  *
 496  * The only data_len supported by HAMMER userspace for large data zone
 497  * (zone 10) is HAMMER_BUFSIZE which is 16KB.  >16KB data does not fit
 498  * in a buffer allocated by get_buffer().  Also alloc_blockmap() does
 499  * not consider >16KB buffer size.
 500  */
 501 void *
 502 alloc_data_element(hammer_off_t *offp, int32_t data_len,
 503                    struct buffer_info **data_bufferp)
 504 {
 505         void *data;
 506         int zone;
 507
 508         if (data_len == 0)
 509                 return(NULL);
 510
 511         zone = hammer_data_zone_index(data_len);
 512         assert(data_len <= HAMMER_BUFSIZE); /* just one buffer */
 513         assert(zone == HAMMER_ZONE_LARGE_DATA_INDEX ||
 514                zone == HAMMER_ZONE_SMALL_DATA_INDEX);
 515
 516         data = alloc_blockmap(zone, data_len, offp, data_bufferp);
 517         bzero(data, data_len);
 518         return(data);
 519 }
 520
 521 /*
 522  * Format a new blockmap.  This is mostly a degenerate case because
 523  * all allocations are now actually done from the freemap.
 524  */
 525 void
 526 format_blockmap(struct volume_info *root_vol, int zone, hammer_off_t offset)
 527 {
 528         hammer_blockmap_t blockmap;
 529         hammer_off_t zone_base;
 530
 531         /* Only root volume needs formatting */
 532         assert(root_vol->vol_no == HAMMER_ROOT_VOLNO);
 533
 534         assert(hammer_is_zone2_mapped_index(zone));
 535
 536         blockmap = &root_vol->ondisk->vol0_blockmap[zone];
 537         zone_base = HAMMER_ZONE_ENCODE(zone, offset);
 538
 539         bzero(blockmap, sizeof(*blockmap));
 540         blockmap->phys_offset = 0;
 541         blockmap->first_offset = zone_base;
 542         blockmap->next_offset = zone_base;
 543         blockmap->alloc_offset = HAMMER_ENCODE(zone, 255, -1);
 544         blockmap->entry_crc = crc32(blockmap, HAMMER_BLOCKMAP_CRCSIZE);
 545 }
 546
 547 /*
 548  * Format a new freemap.  Set all layer1 entries to UNAVAIL.  The initialize
 549  * code will load each volume's freemap.
 550  */
 551 void
 552 format_freemap(struct volume_info *root_vol)
 553 {
 554         struct buffer_info *buffer = NULL;
 555         hammer_off_t layer1_offset;
 556         hammer_blockmap_t blockmap;
 557         struct hammer_blockmap_layer1 *layer1;
 558         int i, isnew;
 559
 560         /* Only root volume needs formatting */
 561         assert(root_vol->vol_no == HAMMER_ROOT_VOLNO);
 562
 563         layer1_offset = alloc_bigblock(root_vol, HAMMER_ZONE_FREEMAP_INDEX);
 564         for (i = 0; i < HAMMER_BIGBLOCK_SIZE; i += sizeof(*layer1)) {
 565                 isnew = ((i % HAMMER_BUFSIZE) == 0);
 566                 layer1 = get_buffer_data(layer1_offset + i, &buffer, isnew);
 567                 bzero(layer1, sizeof(*layer1));
 568                 layer1->phys_offset = HAMMER_BLOCKMAP_UNAVAIL;
 569                 layer1->blocks_free = 0;
 570                 layer1->layer1_crc = crc32(layer1, HAMMER_LAYER1_CRCSIZE);
 571         }
 572         assert(i == HAMMER_BIGBLOCK_SIZE);
 573         rel_buffer(buffer);
 574
 575         blockmap = &root_vol->ondisk->vol0_blockmap[HAMMER_ZONE_FREEMAP_INDEX];
 576         bzero(blockmap, sizeof(*blockmap));
 577         blockmap->phys_offset = layer1_offset;
 578         blockmap->first_offset = 0;
 579         blockmap->next_offset = HAMMER_ENCODE_RAW_BUFFER(0, 0);
 580         blockmap->alloc_offset = HAMMER_ENCODE_RAW_BUFFER(255, -1);
 581         blockmap->entry_crc = crc32(blockmap, HAMMER_BLOCKMAP_CRCSIZE);
 582 }
 583
 584 /*
 585  * Load the volume's remaining free space into the freemap.
 586  *
 587  * Returns the number of big-blocks available.
 588  */
 589 int64_t
 590 initialize_freemap(struct volume_info *vol)
 591 {
 592         struct volume_info *root_vol;
 593         struct buffer_info *buffer1 = NULL;
 594         struct buffer_info *buffer2 = NULL;
 595         struct hammer_blockmap_layer1 *layer1;
 596         struct hammer_blockmap_layer2 *layer2;
 597         hammer_off_t layer1_offset;
 598         hammer_off_t layer2_offset;
 599         hammer_off_t phys_offset;
 600         hammer_off_t block_offset;
 601         hammer_off_t aligned_vol_free_end;
 602         hammer_blockmap_t freemap;
 603         int64_t count = 0;
 604         int64_t layer1_count = 0;
 605
 606         root_vol = get_root_volume();
 607         aligned_vol_free_end = (vol->vol_free_end + HAMMER_BLOCKMAP_LAYER2_MASK)
 608                                 & ~HAMMER_BLOCKMAP_LAYER2_MASK;
 609
 610         printf("initialize freemap volume %d\n", vol->vol_no);
 611
 612         /*
 613          * Initialize the freemap.  First preallocate the big-blocks required
 614          * to implement layer2.   This preallocation is a bootstrap allocation
 615          * using blocks from the target volume.
 616          */
 617         freemap = &root_vol->ondisk->vol0_blockmap[HAMMER_ZONE_FREEMAP_INDEX];
 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 = freemap->phys_offset +
 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 = freemap->phys_offset +
 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 (writehammervol(volume) == -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(buffer) == -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 __read(struct volume_info *vol, void *data, int64_t offset, int size)
 872 {
 873         ssize_t n;
 874
 875         n = pread(vol->fd, data, size, offset);
 876         if (n != size)
 877                 return(-1);
 878         return(0);
 879 }
 880
 881 static __inline int
 882 readhammervol(struct volume_info *vol)
 883 {
 884         return(__read(vol, vol->ondisk, 0, HAMMER_BUFSIZE));
 885 }
 886
 887 static __inline int
 888 readhammerbuf(struct buffer_info *buf)
 889 {
 890         return(__read(buf->volume, buf->ondisk, buf->raw_offset, HAMMER_BUFSIZE));
 891 }
 892
 893 static int
 894 __write(struct volume_info *vol, const void *data, int64_t offset, int size)
 895 {
 896         ssize_t n;
 897
 898         if (vol->rdonly)
 899                 return(0);
 900
 901         n = pwrite(vol->fd, data, size, offset);
 902         if (n != size)
 903                 return(-1);
 904         return(0);
 905 }
 906
 907 static __inline int
 908 writehammervol(struct volume_info *vol)
 909 {
 910         return(__write(vol, vol->ondisk, 0, HAMMER_BUFSIZE));
 911 }
 912
 913 static __inline int
 914 writehammerbuf(struct buffer_info *buf)
 915 {
 916         return(__write(buf->volume, buf->ondisk, buf->raw_offset, HAMMER_BUFSIZE));
 917 }
 918
 919 int64_t init_boot_area_size(int64_t value, off_t avg_vol_size)
 920 {
 921         if (value == 0) {
 922                 value = HAMMER_BOOT_NOMBYTES;
 923                 while (value > avg_vol_size / HAMMER_MAX_VOLUMES)
 924                         value >>= 1;
 925                 if (value < HAMMER_BOOT_MINBYTES)
 926                         value = 0;
 927         } else if (value < HAMMER_BOOT_MINBYTES) {
 928                 value = HAMMER_BOOT_MINBYTES;
 929         }
 930
 931         return(value);
 932 }
 933
 934 int64_t init_mem_area_size(int64_t value, off_t avg_vol_size)
 935 {
 936         if (value == 0) {
 937                 value = HAMMER_MEM_NOMBYTES;
 938                 while (value > avg_vol_size / HAMMER_MAX_VOLUMES)
 939                         value >>= 1;
 940                 if (value < HAMMER_MEM_MINBYTES)
 941                         value = 0;
 942         } else if (value < HAMMER_MEM_MINBYTES) {
 943                 value = HAMMER_MEM_MINBYTES;
 944         }
 945
 946         return(value);
 947 }