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         void *ondisk;
 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                 hi = buffer_hash(buf_offset);
 312                 TAILQ_INSERT_TAIL(&volume->buffer_lists[hi], buf, entry);
 313                 buf->cache.buffer = buf;
 314                 hammer_cache_add(&buf->cache);
 315                 dora = (isnew == 0);
 316         } else {
 317                 if (DebugOpt > 1) {
 318                         fprintf(stderr, "get_buffer: %016jx %016jx at %p *\n",
 319                                 (intmax_t)orig_offset, (intmax_t)buf_offset,
 320                                 buf);
 321                 }
 322                 hammer_cache_used(&buf->cache);
 323                 ++buf->use_count;
 324         }
 325         ++buf->cache.refs;
 326         hammer_cache_flush();
 327         if ((ondisk = buf->ondisk) == NULL) {
 328                 buf->ondisk = ondisk = malloc(HAMMER_BUFSIZE);
 329                 if (isnew <= 0) {
 330                         n = readhammerbuf(volume, ondisk, buf->raw_offset);
 331                         if (n == -1) {
 332                                 if (AssertOnFailure)
 333                                         err(1, "get_buffer: %s:%016jx "
 334                                             "Read failed at offset %016jx",
 335                                             volume->name,
 336                                             (intmax_t)buf->buf_offset,
 337                                             (intmax_t)buf->raw_offset);
 338                                 bzero(ondisk, HAMMER_BUFSIZE);
 339                         }
 340                 }
 341         }
 342         if (isnew > 0) {
 343                 bzero(ondisk, HAMMER_BUFSIZE);
 344                 buf->cache.modified = 1;
 345         }
 346         if (dora)
 347                 get_buffer_readahead(buf);
 348         return(buf);
 349 }
 350
 351 static void
 352 get_buffer_readahead(struct buffer_info *base)
 353 {
 354         struct buffer_info *buf;
 355         struct volume_info *vol;
 356         hammer_off_t buf_offset;
 357         int64_t raw_offset;
 358         int ri = UseReadBehind;
 359         int re = UseReadAhead;
 360
 361         raw_offset = base->raw_offset + ri * HAMMER_BUFSIZE;
 362         vol = base->volume;
 363
 364         while (ri < re) {
 365                 if (raw_offset >= vol->ondisk->vol_buf_end)
 366                         break;
 367                 if (raw_offset < vol->ondisk->vol_buf_beg || ri == 0) {
 368                         ++ri;
 369                         raw_offset += HAMMER_BUFSIZE;
 370                         continue;
 371                 }
 372                 buf_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no,
 373                         raw_offset - vol->ondisk->vol_buf_beg);
 374                 buf = find_buffer(vol, buf_offset);
 375                 if (buf == NULL) {
 376                         buf = get_buffer(buf_offset, -1);
 377                         rel_buffer(buf);
 378                 }
 379                 ++ri;
 380                 raw_offset += HAMMER_BUFSIZE;
 381         }
 382 }
 383
 384 void
 385 rel_buffer(struct buffer_info *buffer)
 386 {
 387         struct volume_info *volume;
 388         int hi;
 389
 390         if (buffer == NULL)
 391                 return;
 392         assert(buffer->cache.refs > 0);
 393         if (--buffer->cache.refs == 0) {
 394                 if (buffer->cache.delete) {
 395                         hi = buffer_hash(buffer->buf_offset);
 396                         volume = buffer->volume;
 397                         if (buffer->cache.modified)
 398                                 flush_buffer(buffer);
 399                         TAILQ_REMOVE(&volume->buffer_lists[hi], buffer, entry);
 400                         hammer_cache_del(&buffer->cache);
 401                         free(buffer->ondisk);
 402                         free(buffer);
 403                         rel_volume(volume);
 404                 }
 405         }
 406 }
 407
 408 /*
 409  * Retrieve a pointer to a buffer data given a buffer offset.  The underlying
 410  * bufferp is freed if isnew or the offset is out of range of the cached data.
 411  * If bufferp is freed a referenced buffer is loaded into it.
 412  */
 413 void *
 414 get_buffer_data(hammer_off_t buf_offset, struct buffer_info **bufferp,
 415                 int isnew)
 416 {
 417         if (*bufferp != NULL) {
 418                 if (isnew > 0 ||
 419                     (((*bufferp)->buf_offset ^ buf_offset) & ~HAMMER_BUFMASK64)) {
 420                         rel_buffer(*bufferp);
 421                         *bufferp = NULL;
 422                 }
 423         }
 424         return(get_ondisk(buf_offset, bufferp, isnew));
 425 }
 426
 427 /*
 428  * Retrieve a pointer to a B-Tree node given a zone offset.  The underlying
 429  * bufferp is freed if non-NULL and a referenced buffer is loaded into it.
 430  */
 431 hammer_node_ondisk_t
 432 get_node(hammer_off_t node_offset, struct buffer_info **bufferp)
 433 {
 434         if (*bufferp != NULL) {
 435                 rel_buffer(*bufferp);
 436                 *bufferp = NULL;
 437         }
 438         return(get_ondisk(node_offset, bufferp, 0));
 439 }
 440
 441 /*
 442  * Return a pointer to a buffer data given a buffer offset.
 443  * If *bufferp is NULL acquire the buffer otherwise use that buffer.
 444  */
 445 static void *
 446 get_ondisk(hammer_off_t buf_offset, struct buffer_info **bufferp, int isnew)
 447 {
 448         struct buffer_info *buffer;
 449
 450         buffer = *bufferp;
 451         if (buffer == NULL) {
 452                 buffer = *bufferp = get_buffer(buf_offset, isnew);
 453                 if (buffer == NULL)
 454                         return(NULL);
 455         }
 456
 457         return((char *)buffer->ondisk +
 458                 ((int32_t)buf_offset & HAMMER_BUFMASK));
 459 }
 460
 461 /*
 462  * Allocate HAMMER elements - B-Tree nodse
 463  */
 464 void *
 465 alloc_btree_element(hammer_off_t *offp, struct buffer_info **data_bufferp)
 466 {
 467         hammer_node_ondisk_t node;
 468
 469         node = alloc_blockmap(HAMMER_ZONE_BTREE_INDEX, sizeof(*node),
 470                               offp, data_bufferp);
 471         bzero(node, sizeof(*node));
 472         return (node);
 473 }
 474
 475 /*
 476  * Allocate HAMMER elements - meta data (inode, direntry, PFS, etc)
 477  */
 478 void *
 479 alloc_meta_element(hammer_off_t *offp, int32_t data_len,
 480                    struct buffer_info **data_bufferp)
 481 {
 482         void *data;
 483
 484         data = alloc_blockmap(HAMMER_ZONE_META_INDEX, data_len,
 485                               offp, data_bufferp);
 486         bzero(data, data_len);
 487         return (data);
 488 }
 489
 490 /*
 491  * Allocate HAMMER elements - data storage
 492  *
 493  * The only data_len supported by HAMMER userspace for large data zone
 494  * (zone 10) is HAMMER_BUFSIZE which is 16KB.  >16KB data does not fit
 495  * in a buffer allocated by get_buffer().  Also alloc_blockmap() does
 496  * not consider >16KB buffer size.
 497  */
 498 void *
 499 alloc_data_element(hammer_off_t *offp, int32_t data_len,
 500                    struct buffer_info **data_bufferp)
 501 {
 502         void *data;
 503         int zone;
 504
 505         if (data_len == 0)
 506                 return(NULL);
 507
 508         zone = hammer_data_zone_index(data_len);
 509         assert(data_len <= HAMMER_BUFSIZE); /* just one buffer */
 510         assert(zone == HAMMER_ZONE_LARGE_DATA_INDEX ||
 511                zone == HAMMER_ZONE_SMALL_DATA_INDEX);
 512
 513         data = alloc_blockmap(zone, data_len, offp, data_bufferp);
 514         bzero(data, data_len);
 515         return(data);
 516 }
 517
 518 /*
 519  * Format a new blockmap.  This is mostly a degenerate case because
 520  * all allocations are now actually done from the freemap.
 521  */
 522 void
 523 format_blockmap(struct volume_info *root_vol, int zone, hammer_off_t offset)
 524 {
 525         hammer_blockmap_t blockmap;
 526         hammer_off_t zone_base;
 527
 528         /* Only root volume needs formatting */
 529         assert(root_vol->vol_no == HAMMER_ROOT_VOLNO);
 530
 531         assert(hammer_is_zone2_mapped_index(zone));
 532
 533         blockmap = &root_vol->ondisk->vol0_blockmap[zone];
 534         zone_base = HAMMER_ZONE_ENCODE(zone, offset);
 535
 536         bzero(blockmap, sizeof(*blockmap));
 537         blockmap->phys_offset = 0;
 538         blockmap->first_offset = zone_base;
 539         blockmap->next_offset = zone_base;
 540         blockmap->alloc_offset = HAMMER_ENCODE(zone, 255, -1);
 541         blockmap->entry_crc = crc32(blockmap, HAMMER_BLOCKMAP_CRCSIZE);
 542 }
 543
 544 /*
 545  * Format a new freemap.  Set all layer1 entries to UNAVAIL.  The initialize
 546  * code will load each volume's freemap.
 547  */
 548 void
 549 format_freemap(struct volume_info *root_vol)
 550 {
 551         struct buffer_info *buffer = NULL;
 552         hammer_off_t layer1_offset;
 553         hammer_blockmap_t blockmap;
 554         struct hammer_blockmap_layer1 *layer1;
 555         int i, isnew;
 556
 557         /* Only root volume needs formatting */
 558         assert(root_vol->vol_no == HAMMER_ROOT_VOLNO);
 559
 560         layer1_offset = alloc_bigblock(root_vol, HAMMER_ZONE_FREEMAP_INDEX);
 561         for (i = 0; i < HAMMER_BIGBLOCK_SIZE; i += sizeof(*layer1)) {
 562                 isnew = ((i % HAMMER_BUFSIZE) == 0);
 563                 layer1 = get_buffer_data(layer1_offset + i, &buffer, isnew);
 564                 bzero(layer1, sizeof(*layer1));
 565                 layer1->phys_offset = HAMMER_BLOCKMAP_UNAVAIL;
 566                 layer1->blocks_free = 0;
 567                 layer1->layer1_crc = crc32(layer1, HAMMER_LAYER1_CRCSIZE);
 568         }
 569         assert(i == HAMMER_BIGBLOCK_SIZE);
 570         rel_buffer(buffer);
 571
 572         blockmap = &root_vol->ondisk->vol0_blockmap[HAMMER_ZONE_FREEMAP_INDEX];
 573         bzero(blockmap, sizeof(*blockmap));
 574         blockmap->phys_offset = layer1_offset;
 575         blockmap->first_offset = 0;
 576         blockmap->next_offset = HAMMER_ENCODE_RAW_BUFFER(0, 0);
 577         blockmap->alloc_offset = HAMMER_ENCODE_RAW_BUFFER(255, -1);
 578         blockmap->entry_crc = crc32(blockmap, HAMMER_BLOCKMAP_CRCSIZE);
 579 }
 580
 581 /*
 582  * Load the volume's remaining free space into the freemap.
 583  *
 584  * Returns the number of big-blocks available.
 585  */
 586 int64_t
 587 initialize_freemap(struct volume_info *vol)
 588 {
 589         struct volume_info *root_vol;
 590         struct buffer_info *buffer1 = NULL;
 591         struct buffer_info *buffer2 = NULL;
 592         struct hammer_blockmap_layer1 *layer1;
 593         struct hammer_blockmap_layer2 *layer2;
 594         hammer_off_t layer1_base;
 595         hammer_off_t layer1_offset;
 596         hammer_off_t layer2_offset;
 597         hammer_off_t phys_offset;
 598         hammer_off_t block_offset;
 599         hammer_off_t aligned_vol_free_end;
 600         hammer_blockmap_t freemap;
 601         int64_t count = 0;
 602         int64_t layer1_count = 0;
 603
 604         root_vol = get_root_volume();
 605         aligned_vol_free_end = (vol->vol_free_end + HAMMER_BLOCKMAP_LAYER2_MASK)
 606                                 & ~HAMMER_BLOCKMAP_LAYER2_MASK;
 607
 608         printf("initialize freemap volume %d\n", vol->vol_no);
 609
 610         /*
 611          * Initialize the freemap.  First preallocate the big-blocks required
 612          * to implement layer2.   This preallocation is a bootstrap allocation
 613          * using blocks from the target volume.
 614          */
 615         freemap = &root_vol->ondisk->vol0_blockmap[HAMMER_ZONE_FREEMAP_INDEX];
 616         layer1_base = freemap->phys_offset;
 617
 618         for (phys_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no, 0);
 619              phys_offset < aligned_vol_free_end;
 620              phys_offset += HAMMER_BLOCKMAP_LAYER2) {
 621                 layer1_offset = layer1_base +
 622                                 HAMMER_BLOCKMAP_LAYER1_OFFSET(phys_offset);
 623                 layer1 = get_buffer_data(layer1_offset, &buffer1, 0);
 624                 if (layer1->phys_offset == HAMMER_BLOCKMAP_UNAVAIL) {
 625                         layer1->phys_offset = alloc_bigblock(vol,
 626                                                 HAMMER_ZONE_FREEMAP_INDEX);
 627                         layer1->blocks_free = 0;
 628                         buffer1->cache.modified = 1;
 629                         layer1->layer1_crc = crc32(layer1,
 630                                                    HAMMER_LAYER1_CRCSIZE);
 631                 }
 632         }
 633
 634         /*
 635          * Now fill everything in.
 636          */
 637         for (phys_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no, 0);
 638              phys_offset < aligned_vol_free_end;
 639              phys_offset += HAMMER_BLOCKMAP_LAYER2) {
 640                 layer1_count = 0;
 641                 layer1_offset = layer1_base +
 642                                 HAMMER_BLOCKMAP_LAYER1_OFFSET(phys_offset);
 643                 layer1 = get_buffer_data(layer1_offset, &buffer1, 0);
 644                 assert(layer1->phys_offset != HAMMER_BLOCKMAP_UNAVAIL);
 645
 646                 for (block_offset = 0;
 647                      block_offset < HAMMER_BLOCKMAP_LAYER2;
 648                      block_offset += HAMMER_BIGBLOCK_SIZE) {
 649                         layer2_offset = layer1->phys_offset +
 650                                         HAMMER_BLOCKMAP_LAYER2_OFFSET(block_offset);
 651                         layer2 = get_buffer_data(layer2_offset, &buffer2, 0);
 652                         bzero(layer2, sizeof(*layer2));
 653
 654                         if (phys_offset + block_offset < vol->vol_free_off) {
 655                                 /*
 656                                  * Fixups XXX - big-blocks already allocated as part
 657                                  * of the freemap bootstrap.
 658                                  */
 659                                 layer2->zone = HAMMER_ZONE_FREEMAP_INDEX;
 660                                 layer2->append_off = HAMMER_BIGBLOCK_SIZE;
 661                                 layer2->bytes_free = 0;
 662                         } else if (phys_offset + block_offset < vol->vol_free_end) {
 663                                 layer2->zone = 0;
 664                                 layer2->append_off = 0;
 665                                 layer2->bytes_free = HAMMER_BIGBLOCK_SIZE;
 666                                 ++count;
 667                                 ++layer1_count;
 668                         } else {
 669                                 layer2->zone = HAMMER_ZONE_UNAVAIL_INDEX;
 670                                 layer2->append_off = HAMMER_BIGBLOCK_SIZE;
 671                                 layer2->bytes_free = 0;
 672                         }
 673                         layer2->entry_crc = crc32(layer2, HAMMER_LAYER2_CRCSIZE);
 674                         buffer2->cache.modified = 1;
 675                 }
 676
 677                 layer1->blocks_free += layer1_count;
 678                 layer1->layer1_crc = crc32(layer1, HAMMER_LAYER1_CRCSIZE);
 679                 buffer1->cache.modified = 1;
 680         }
 681
 682         rel_buffer(buffer1);
 683         rel_buffer(buffer2);
 684         rel_volume(root_vol);
 685         return(count);
 686 }
 687
 688 /*
 689  * Returns the number of big-blocks available for filesystem data and undos
 690  * without formatting.
 691  */
 692 int64_t
 693 count_freemap(struct volume_info *vol)
 694 {
 695         hammer_off_t phys_offset;
 696         hammer_off_t vol_free_off;
 697         hammer_off_t aligned_vol_free_end;
 698         int64_t count = 0;
 699
 700         vol_free_off = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no, 0);
 701         aligned_vol_free_end = (vol->vol_free_end + HAMMER_BLOCKMAP_LAYER2_MASK)
 702                                 & ~HAMMER_BLOCKMAP_LAYER2_MASK;
 703
 704         if (vol->vol_no == HAMMER_ROOT_VOLNO)
 705                 vol_free_off += HAMMER_BIGBLOCK_SIZE;
 706
 707         for (phys_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no, 0);
 708              phys_offset < aligned_vol_free_end;
 709              phys_offset += HAMMER_BLOCKMAP_LAYER2) {
 710                 vol_free_off += HAMMER_BIGBLOCK_SIZE;
 711         }
 712
 713         for (phys_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no, 0);
 714              phys_offset < aligned_vol_free_end;
 715              phys_offset += HAMMER_BIGBLOCK_SIZE) {
 716                 if (phys_offset < vol_free_off) {
 717                         ;
 718                 } else if (phys_offset < vol->vol_free_end) {
 719                         ++count;
 720                 }
 721         }
 722
 723         return(count);
 724 }
 725
 726 /*
 727  * Format the undomap for the root volume.
 728  */
 729 void
 730 format_undomap(struct volume_info *root_vol, int64_t *undo_buffer_size)
 731 {
 732         const int undo_zone = HAMMER_ZONE_UNDO_INDEX;
 733         hammer_off_t undo_limit;
 734         hammer_blockmap_t blockmap;
 735         struct hammer_volume_ondisk *ondisk;
 736         struct buffer_info *buffer = NULL;
 737         hammer_off_t scan;
 738         int n;
 739         int limit_index;
 740         uint32_t seqno;
 741
 742         /* Only root volume needs formatting */
 743         assert(root_vol->vol_no == HAMMER_ROOT_VOLNO);
 744         ondisk = root_vol->ondisk;
 745
 746         /*
 747          * Size the undo buffer in multiples of HAMMER_BIGBLOCK_SIZE,
 748          * up to HAMMER_UNDO_LAYER2 big-blocks.  Size to approximately
 749          * 0.1% of the disk.
 750          *
 751          * The minimum UNDO fifo size is 500MB, or approximately 1% of
 752          * the recommended 50G disk.
 753          *
 754          * Changing this minimum is rather dangerous as complex filesystem
 755          * operations can cause the UNDO FIFO to fill up otherwise.
 756          */
 757         undo_limit = *undo_buffer_size;
 758         if (undo_limit == 0) {
 759                 undo_limit = (ondisk->vol_buf_end - ondisk->vol_buf_beg) / 1000;
 760                 if (undo_limit < 500*1024*1024)
 761                         undo_limit = 500*1024*1024;
 762         }
 763         undo_limit = (undo_limit + HAMMER_BIGBLOCK_MASK64) &
 764                      ~HAMMER_BIGBLOCK_MASK64;
 765         if (undo_limit < HAMMER_BIGBLOCK_SIZE)
 766                 undo_limit = HAMMER_BIGBLOCK_SIZE;
 767         if (undo_limit > HAMMER_BIGBLOCK_SIZE * HAMMER_UNDO_LAYER2)
 768                 undo_limit = HAMMER_BIGBLOCK_SIZE * HAMMER_UNDO_LAYER2;
 769         *undo_buffer_size = undo_limit;
 770
 771         blockmap = &ondisk->vol0_blockmap[undo_zone];
 772         bzero(blockmap, sizeof(*blockmap));
 773         blockmap->phys_offset = HAMMER_BLOCKMAP_UNAVAIL;
 774         blockmap->first_offset = HAMMER_ZONE_ENCODE(undo_zone, 0);
 775         blockmap->next_offset = blockmap->first_offset;
 776         blockmap->alloc_offset = HAMMER_ZONE_ENCODE(undo_zone, undo_limit);
 777         blockmap->entry_crc = crc32(blockmap, HAMMER_BLOCKMAP_CRCSIZE);
 778
 779         limit_index = undo_limit / HAMMER_BIGBLOCK_SIZE;
 780         assert(limit_index <= HAMMER_UNDO_LAYER2);
 781
 782         for (n = 0; n < limit_index; ++n) {
 783                 ondisk->vol0_undo_array[n] = alloc_bigblock(root_vol,
 784                                                         HAMMER_ZONE_UNDO_INDEX);
 785         }
 786         while (n < HAMMER_UNDO_LAYER2) {
 787                 ondisk->vol0_undo_array[n++] = HAMMER_BLOCKMAP_UNAVAIL;
 788         }
 789
 790         /*
 791          * Pre-initialize the UNDO blocks (HAMMER version 4+)
 792          */
 793         printf("initializing the undo map (%jd MB)\n",
 794                 (intmax_t)(blockmap->alloc_offset & HAMMER_OFF_LONG_MASK) /
 795                 (1024 * 1024));
 796
 797         scan = blockmap->first_offset;
 798         seqno = 0;
 799
 800         while (scan < blockmap->alloc_offset) {
 801                 hammer_fifo_head_t head;
 802                 hammer_fifo_tail_t tail;
 803                 int isnew;
 804                 int bytes = HAMMER_UNDO_ALIGN;
 805
 806                 isnew = ((scan & HAMMER_BUFMASK64) == 0);
 807                 head = get_buffer_data(scan, &buffer, isnew);
 808                 buffer->cache.modified = 1;
 809                 tail = (void *)((char *)head + bytes - sizeof(*tail));
 810
 811                 bzero(head, bytes);
 812                 head->hdr_signature = HAMMER_HEAD_SIGNATURE;
 813                 head->hdr_type = HAMMER_HEAD_TYPE_DUMMY;
 814                 head->hdr_size = bytes;
 815                 head->hdr_seq = seqno++;
 816
 817                 tail->tail_signature = HAMMER_TAIL_SIGNATURE;
 818                 tail->tail_type = HAMMER_HEAD_TYPE_DUMMY;
 819                 tail->tail_size = bytes;
 820
 821                 head->hdr_crc = crc32(head, HAMMER_FIFO_HEAD_CRCOFF) ^
 822                                 crc32(head + 1, bytes - sizeof(*head));
 823
 824                 scan += bytes;
 825         }
 826         rel_buffer(buffer);
 827 }
 828
 829 /*
 830  * Flush various tracking structures to disk
 831  */
 832 void
 833 flush_all_volumes(void)
 834 {
 835         struct volume_info *vol;
 836
 837         TAILQ_FOREACH(vol, &VolList, entry)
 838                 flush_volume(vol);
 839 }
 840
 841 void
 842 flush_volume(struct volume_info *volume)
 843 {
 844         struct buffer_info *buffer;
 845         int i;
 846
 847         for (i = 0; i < HAMMER_BUFLISTS; ++i) {
 848                 TAILQ_FOREACH(buffer, &volume->buffer_lists[i], entry)
 849                         flush_buffer(buffer);
 850         }
 851         if (writehammerbuf(volume, volume->ondisk, 0) == -1)
 852                 err(1, "Write volume %d (%s)", volume->vol_no, volume->name);
 853 }
 854
 855 void
 856 flush_buffer(struct buffer_info *buffer)
 857 {
 858         struct volume_info *vol;
 859
 860         vol = buffer->volume;
 861         if (writehammerbuf(vol, buffer->ondisk, buffer->raw_offset) == -1)
 862                 err(1, "Write volume %d (%s)", vol->vol_no, vol->name);
 863         buffer->cache.modified = 0;
 864 }
 865
 866 /*
 867  * Core I/O operations
 868  */
 869 static int
 870 readhammerbuf(struct volume_info *vol, void *data, int64_t offset)
 871 {
 872         ssize_t n;
 873
 874         n = pread(vol->fd, data, HAMMER_BUFSIZE, offset);
 875         if (n != HAMMER_BUFSIZE)
 876                 return(-1);
 877         return(0);
 878 }
 879
 880 static int
 881 writehammerbuf(struct volume_info *vol, const void *data, int64_t offset)
 882 {
 883         ssize_t n;
 884
 885         if (vol->rdonly)
 886                 return(0);
 887
 888         n = pwrite(vol->fd, data, HAMMER_BUFSIZE, offset);
 889         if (n != HAMMER_BUFSIZE)
 890                 return(-1);
 891         return(0);
 892 }
 893
 894 int64_t init_boot_area_size(int64_t value, off_t avg_vol_size)
 895 {
 896         if (value == 0) {
 897                 value = HAMMER_BOOT_NOMBYTES;
 898                 while (value > avg_vol_size / HAMMER_MAX_VOLUMES)
 899                         value >>= 1;
 900                 if (value < HAMMER_BOOT_MINBYTES)
 901                         value = 0;
 902         } else if (value < HAMMER_BOOT_MINBYTES) {
 903                 value = HAMMER_BOOT_MINBYTES;
 904         }
 905
 906         return(value);
 907 }
 908
 909 int64_t init_mem_area_size(int64_t value, off_t avg_vol_size)
 910 {
 911         if (value == 0) {
 912                 value = HAMMER_MEM_NOMBYTES;
 913                 while (value > avg_vol_size / HAMMER_MAX_VOLUMES)
 914                         value >>= 1;
 915                 if (value < HAMMER_MEM_MINBYTES)
 916                         value = 0;
 917         } else if (value < HAMMER_MEM_MINBYTES) {
 918                 value = HAMMER_MEM_MINBYTES;
 919         }
 920
 921         return(value);
 922 }