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 __inline void *get_ondisk(hammer_off_t buf_offset,
  42                         struct buffer_info **bufferp, 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 int64_t BootAreaSize;
  52 int64_t MemAreaSize;
  53 int64_t UndoBufferSize;
  54 int     UseReadBehind = -4;
  55 int     UseReadAhead = 4;
  56 int     AssertOnFailure = 1;
  57 struct volume_list VolList = TAILQ_HEAD_INITIALIZER(VolList);
  58
  59 static __inline
  60 int
  61 buffer_hash(hammer_off_t buf_offset)
  62 {
  63         int hi;
  64
  65         hi = (int)(buf_offset / HAMMER_BUFSIZE) & HAMMER_BUFLISTMASK;
  66         return(hi);
  67 }
  68
  69 static struct buffer_info*
  70 find_buffer(struct volume_info *volume, hammer_off_t buf_offset)
  71 {
  72         int hi;
  73         struct buffer_info *buf;
  74
  75         hi = buffer_hash(buf_offset);
  76         TAILQ_FOREACH(buf, &volume->buffer_lists[hi], entry)
  77                 if (buf->buf_offset == buf_offset)
  78                         return(buf);
  79         return(NULL);
  80 }
  81
  82 static
  83 struct volume_info *
  84 __alloc_volume(const char *volname, int oflags)
  85 {
  86         struct volume_info *vol;
  87         int i;
  88
  89         vol = malloc(sizeof(*vol));
  90         if (vol == NULL)
  91                 err(1, "alloc_volume");
  92         bzero(vol, sizeof(*vol));
  93
  94         vol->vol_no = -1;
  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         vol->cache.modified = 1;
 154
 155         __add_volume(vol);
 156
 157         return(vol);
 158 }
 159
 160 /*
 161  * Initialize a volume structure and read ondisk volume header.
 162  */
 163 struct volume_info*
 164 load_volume(const char *filename, int oflags)
 165 {
 166         struct volume_info *vol;
 167         struct hammer_volume_ondisk *ondisk;
 168         int n;
 169
 170         vol = __alloc_volume(filename, oflags);
 171         ondisk = vol->ondisk;
 172
 173         n = readhammerbuf(vol, ondisk, 0);
 174         if (n == -1) {
 175                 err(1, "load_volume: %s: Read failed at offset 0", vol->name);
 176         }
 177         vol->vol_no = ondisk->vol_no;
 178
 179         if (ondisk->vol_rootvol != HAMMER_ROOT_VOLNO) {
 180                 errx(1, "load_volume: Invalid root volume# %d",
 181                         ondisk->vol_rootvol);
 182         }
 183
 184         if (bcmp(&Hammer_FSType, &ondisk->vol_fstype, sizeof(Hammer_FSType))) {
 185                 errx(1, "load_volume: %s: Header does not indicate "
 186                         "that this is a hammer volume", vol->name);
 187         }
 188
 189         if (TAILQ_EMPTY(&VolList)) {
 190                 Hammer_FSId = ondisk->vol_fsid;
 191         } else if (bcmp(&Hammer_FSId, &ondisk->vol_fsid, sizeof(Hammer_FSId))) {
 192                 errx(1, "load_volume: %s: FSId does match other volumes!",
 193                         vol->name);
 194         }
 195
 196         __add_volume(vol);
 197
 198         return(vol);
 199 }
 200
 201 /*
 202  * Check basic volume characteristics.
 203  */
 204 void
 205 check_volume(struct volume_info *vol)
 206 {
 207         struct partinfo pinfo;
 208         struct stat st;
 209
 210         /*
 211          * Get basic information about the volume
 212          */
 213         if (ioctl(vol->fd, DIOCGPART, &pinfo) < 0) {
 214                 /*
 215                  * Allow the formatting of regular files as HAMMER volumes
 216                  */
 217                 if (fstat(vol->fd, &st) < 0)
 218                         err(1, "Unable to stat %s", vol->name);
 219                 vol->size = st.st_size;
 220                 vol->type = "REGFILE";
 221         } else {
 222                 /*
 223                  * When formatting a block device as a HAMMER volume the
 224                  * sector size must be compatible.  HAMMER uses 16384 byte
 225                  * filesystem buffers.
 226                  */
 227                 if (pinfo.reserved_blocks) {
 228                         errx(1, "HAMMER cannot be placed in a partition "
 229                                 "which overlaps the disklabel or MBR");
 230                 }
 231                 if (pinfo.media_blksize > HAMMER_BUFSIZE ||
 232                     HAMMER_BUFSIZE % pinfo.media_blksize) {
 233                         errx(1, "A media sector size of %d is not supported",
 234                              pinfo.media_blksize);
 235                 }
 236
 237                 vol->size = pinfo.media_size;
 238                 vol->device_offset = pinfo.media_offset;
 239                 vol->type = "DEVICE";
 240         }
 241 }
 242
 243 struct volume_info *
 244 get_volume(int32_t vol_no)
 245 {
 246         struct volume_info *vol;
 247
 248         TAILQ_FOREACH(vol, &VolList, entry) {
 249                 if (vol->vol_no == vol_no)
 250                         break;
 251         }
 252         if (vol == NULL) {
 253                 if (AssertOnFailure)
 254                         errx(1, "get_volume: Volume %d does not exist!",
 255                                 vol_no);
 256                 return(NULL);
 257         }
 258         ++vol->cache.refs;
 259         /* not added to or removed from hammer cache */
 260         return(vol);
 261 }
 262
 263 struct volume_info *
 264 get_root_volume(void)
 265 {
 266         return(get_volume(HAMMER_ROOT_VOLNO));
 267 }
 268
 269 void
 270 rel_volume(struct volume_info *volume)
 271 {
 272         if (volume == NULL)
 273                 return;
 274         /* not added to or removed from hammer cache */
 275         --volume->cache.refs;
 276 }
 277
 278 /*
 279  * Acquire the specified buffer.  isnew is -1 only when called
 280  * via get_buffer_readahead() to prevent another readahead.
 281  */
 282 struct buffer_info *
 283 get_buffer(hammer_off_t buf_offset, int isnew)
 284 {
 285         void *ondisk;
 286         struct buffer_info *buf;
 287         struct volume_info *volume;
 288         hammer_off_t orig_offset = buf_offset;
 289         int vol_no;
 290         int zone;
 291         int hi, n;
 292         int dora = 0;
 293
 294         zone = HAMMER_ZONE_DECODE(buf_offset);
 295         if (zone > HAMMER_ZONE_RAW_BUFFER_INDEX) {
 296                 buf_offset = blockmap_lookup(buf_offset, NULL, NULL, NULL);
 297         }
 298         if (buf_offset == HAMMER_OFF_BAD)
 299                 return(NULL);
 300
 301         if (AssertOnFailure) {
 302                 assert((buf_offset & HAMMER_OFF_ZONE_MASK) ==
 303                        HAMMER_ZONE_RAW_BUFFER);
 304         }
 305         vol_no = HAMMER_VOL_DECODE(buf_offset);
 306         volume = get_volume(vol_no);
 307         if (volume == NULL)
 308                 return(NULL);
 309
 310         buf_offset &= ~HAMMER_BUFMASK64;
 311         buf = find_buffer(volume, buf_offset);
 312
 313         if (buf == NULL) {
 314                 buf = malloc(sizeof(*buf));
 315                 bzero(buf, sizeof(*buf));
 316                 if (DebugOpt > 1) {
 317                         fprintf(stderr, "get_buffer: %016llx %016llx at %p\n",
 318                                 (long long)orig_offset, (long long)buf_offset,
 319                                 buf);
 320                 }
 321                 buf->buf_offset = buf_offset;
 322                 buf->raw_offset = hammer_xlate_to_phys(volume->ondisk,
 323                                                         buf_offset);
 324                 buf->volume = volume;
 325                 hi = buffer_hash(buf_offset);
 326                 TAILQ_INSERT_TAIL(&volume->buffer_lists[hi], buf, entry);
 327                 ++volume->cache.refs;
 328                 buf->cache.u.buffer = buf;
 329                 hammer_cache_add(&buf->cache, ISBUFFER);
 330                 dora = (isnew == 0);
 331         } else {
 332                 if (DebugOpt > 1) {
 333                         fprintf(stderr, "get_buffer: %016llx %016llx at %p *\n",
 334                                 (long long)orig_offset, (long long)buf_offset,
 335                                 buf);
 336                 }
 337                 hammer_cache_used(&buf->cache);
 338                 ++buf->use_count;
 339         }
 340         ++buf->cache.refs;
 341         hammer_cache_flush();
 342         if ((ondisk = buf->ondisk) == NULL) {
 343                 buf->ondisk = ondisk = malloc(HAMMER_BUFSIZE);
 344                 if (isnew <= 0) {
 345                         n = readhammerbuf(volume, ondisk, buf->raw_offset);
 346                         if (n == -1) {
 347                                 if (AssertOnFailure)
 348                                         err(1, "get_buffer: %s:%016llx "
 349                                             "Read failed at offset %016llx",
 350                                             volume->name,
 351                                             (long long)buf->buf_offset,
 352                                             (long long)buf->raw_offset);
 353                                 bzero(ondisk, HAMMER_BUFSIZE);
 354                         }
 355                 }
 356         }
 357         if (isnew > 0) {
 358                 bzero(ondisk, HAMMER_BUFSIZE);
 359                 buf->cache.modified = 1;
 360         }
 361         if (dora)
 362                 get_buffer_readahead(buf);
 363         return(buf);
 364 }
 365
 366 static void
 367 get_buffer_readahead(struct buffer_info *base)
 368 {
 369         struct buffer_info *buf;
 370         struct volume_info *vol;
 371         hammer_off_t buf_offset;
 372         int64_t raw_offset;
 373         int ri = UseReadBehind;
 374         int re = UseReadAhead;
 375
 376         raw_offset = base->raw_offset + ri * HAMMER_BUFSIZE;
 377         vol = base->volume;
 378
 379         while (ri < re) {
 380                 if (raw_offset >= vol->ondisk->vol_buf_end)
 381                         break;
 382                 if (raw_offset < vol->ondisk->vol_buf_beg || ri == 0) {
 383                         ++ri;
 384                         raw_offset += HAMMER_BUFSIZE;
 385                         continue;
 386                 }
 387                 buf_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no,
 388                         raw_offset - vol->ondisk->vol_buf_beg);
 389                 buf = find_buffer(vol, buf_offset);
 390                 if (buf == NULL) {
 391                         buf = get_buffer(buf_offset, -1);
 392                         rel_buffer(buf);
 393                 }
 394                 ++ri;
 395                 raw_offset += HAMMER_BUFSIZE;
 396         }
 397 }
 398
 399 void
 400 rel_buffer(struct buffer_info *buffer)
 401 {
 402         struct volume_info *volume;
 403         int hi;
 404
 405         if (buffer == NULL)
 406                 return;
 407         assert(buffer->cache.refs > 0);
 408         if (--buffer->cache.refs == 0) {
 409                 if (buffer->cache.delete) {
 410                         hi = buffer_hash(buffer->buf_offset);
 411                         volume = buffer->volume;
 412                         if (buffer->cache.modified)
 413                                 flush_buffer(buffer);
 414                         TAILQ_REMOVE(&volume->buffer_lists[hi], buffer, entry);
 415                         hammer_cache_del(&buffer->cache);
 416                         free(buffer->ondisk);
 417                         free(buffer);
 418                         rel_volume(volume);
 419                 }
 420         }
 421 }
 422
 423 /*
 424  * Retrieve a pointer to a buffer data given a buffer offset.  The underlying
 425  * bufferp is freed if isnew or the offset is out of range of the cached data.
 426  * If bufferp is freed a referenced buffer is loaded into it.
 427  */
 428 void *
 429 get_buffer_data(hammer_off_t buf_offset, struct buffer_info **bufferp,
 430                 int isnew)
 431 {
 432         if (*bufferp != NULL) {
 433                 if (isnew > 0 ||
 434                     (((*bufferp)->buf_offset ^ buf_offset) & ~HAMMER_BUFMASK64)) {
 435                         rel_buffer(*bufferp);
 436                         *bufferp = NULL;
 437                 }
 438         }
 439         return(get_ondisk(buf_offset, bufferp, isnew));
 440 }
 441
 442 /*
 443  * Retrieve a pointer to a B-Tree node given a zone offset.  The underlying
 444  * bufferp is freed if non-NULL and a referenced buffer is loaded into it.
 445  */
 446 hammer_node_ondisk_t
 447 get_node(hammer_off_t node_offset, struct buffer_info **bufferp)
 448 {
 449         if (*bufferp != NULL) {
 450                 rel_buffer(*bufferp);
 451                 *bufferp = NULL;
 452         }
 453         return(get_ondisk(node_offset, bufferp, 0));
 454 }
 455
 456 /*
 457  * Return a pointer to a buffer data given a buffer offset.
 458  * If *bufferp is NULL acquire the buffer otherwise use that buffer.
 459  */
 460 static __inline
 461 void *
 462 get_ondisk(hammer_off_t buf_offset, struct buffer_info **bufferp, int isnew)
 463 {
 464         struct buffer_info *buffer;
 465
 466         buffer = *bufferp;
 467         if (buffer == NULL) {
 468                 buffer = *bufferp = get_buffer(buf_offset, isnew);
 469                 if (buffer == NULL)
 470                         return(NULL);
 471         }
 472
 473         return((char *)buffer->ondisk +
 474                 ((int32_t)buf_offset & HAMMER_BUFMASK));
 475 }
 476
 477 /*
 478  * Allocate HAMMER elements - btree nodes, meta data, data storage
 479  */
 480 void *
 481 alloc_btree_element(hammer_off_t *offp, struct buffer_info **data_bufferp)
 482 {
 483         hammer_node_ondisk_t node;
 484
 485         node = alloc_blockmap(HAMMER_ZONE_BTREE_INDEX, sizeof(*node),
 486                               offp, data_bufferp);
 487         bzero(node, sizeof(*node));
 488         return (node);
 489 }
 490
 491 void *
 492 alloc_meta_element(hammer_off_t *offp, int32_t data_len,
 493                    struct buffer_info **data_bufferp)
 494 {
 495         void *data;
 496
 497         data = alloc_blockmap(HAMMER_ZONE_META_INDEX, data_len,
 498                               offp, data_bufferp);
 499         bzero(data, data_len);
 500         return (data);
 501 }
 502
 503 /*
 504  * The only data_len supported by HAMMER userspace for large data zone
 505  * (zone 10) is HAMMER_BUFSIZE which is 16KB.  >16KB data does not fit
 506  * in a buffer allocated by get_buffer().  Also alloc_blockmap() does
 507  * not consider >16KB buffer size.
 508  */
 509 void *
 510 alloc_data_element(hammer_off_t *offp, int32_t data_len,
 511                    struct buffer_info **data_bufferp)
 512 {
 513         void *data;
 514         int zone;
 515
 516         if (data_len == 0)
 517                 return(NULL);
 518
 519         zone = hammer_data_zone_index(data_len);
 520         assert(data_len <= HAMMER_BUFSIZE); /* just one buffer */
 521         assert(zone == HAMMER_ZONE_LARGE_DATA_INDEX ||
 522                zone == HAMMER_ZONE_SMALL_DATA_INDEX);
 523
 524         data = alloc_blockmap(zone, data_len, offp, data_bufferp);
 525         bzero(data, data_len);
 526         return(data);
 527 }
 528
 529 /*
 530  * Format a new blockmap.  This is mostly a degenerate case because
 531  * all allocations are now actually done from the freemap.
 532  */
 533 void
 534 format_blockmap(struct volume_info *root_vol, int zone, hammer_off_t offset)
 535 {
 536         hammer_blockmap_t blockmap;
 537         hammer_off_t zone_base;
 538
 539         /* Only root volume needs formatting */
 540         assert(root_vol->vol_no == HAMMER_ROOT_VOLNO);
 541
 542         assert(hammer_is_zone2_mapped_index(zone));
 543
 544         blockmap = &root_vol->ondisk->vol0_blockmap[zone];
 545         zone_base = HAMMER_ZONE_ENCODE(zone, offset);
 546
 547         bzero(blockmap, sizeof(*blockmap));
 548         blockmap->phys_offset = 0;
 549         blockmap->first_offset = zone_base;
 550         blockmap->next_offset = zone_base;
 551         blockmap->alloc_offset = HAMMER_ENCODE(zone, 255, -1);
 552         blockmap->entry_crc = crc32(blockmap, HAMMER_BLOCKMAP_CRCSIZE);
 553         root_vol->cache.modified = 1;
 554 }
 555
 556 /*
 557  * Format a new freemap.  Set all layer1 entries to UNAVAIL.  The initialize
 558  * code will load each volume's freemap.
 559  */
 560 void
 561 format_freemap(struct volume_info *root_vol)
 562 {
 563         struct buffer_info *buffer = NULL;
 564         hammer_off_t layer1_offset;
 565         hammer_blockmap_t blockmap;
 566         struct hammer_blockmap_layer1 *layer1;
 567         int i, isnew;
 568
 569         /* Only root volume needs formatting */
 570         assert(root_vol->vol_no == HAMMER_ROOT_VOLNO);
 571
 572         layer1_offset = alloc_bigblock(root_vol, HAMMER_ZONE_FREEMAP_INDEX);
 573         for (i = 0; i < HAMMER_BIGBLOCK_SIZE; i += sizeof(*layer1)) {
 574                 isnew = ((i % HAMMER_BUFSIZE) == 0);
 575                 layer1 = get_buffer_data(layer1_offset + i, &buffer, isnew);
 576                 bzero(layer1, sizeof(*layer1));
 577                 layer1->phys_offset = HAMMER_BLOCKMAP_UNAVAIL;
 578                 layer1->blocks_free = 0;
 579                 layer1->layer1_crc = crc32(layer1, HAMMER_LAYER1_CRCSIZE);
 580         }
 581         assert(i == HAMMER_BIGBLOCK_SIZE);
 582         rel_buffer(buffer);
 583
 584         blockmap = &root_vol->ondisk->vol0_blockmap[HAMMER_ZONE_FREEMAP_INDEX];
 585         bzero(blockmap, sizeof(*blockmap));
 586         blockmap->phys_offset = layer1_offset;
 587         blockmap->first_offset = 0;
 588         blockmap->next_offset = HAMMER_ENCODE_RAW_BUFFER(0, 0);
 589         blockmap->alloc_offset = HAMMER_ENCODE_RAW_BUFFER(255, -1);
 590         blockmap->entry_crc = crc32(blockmap, HAMMER_BLOCKMAP_CRCSIZE);
 591         root_vol->cache.modified = 1;
 592 }
 593
 594 /*
 595  * Load the volume's remaining free space into the freemap.
 596  *
 597  * Returns the number of big-blocks available.
 598  */
 599 int64_t
 600 initialize_freemap(struct volume_info *vol)
 601 {
 602         struct volume_info *root_vol;
 603         struct buffer_info *buffer1 = NULL;
 604         struct buffer_info *buffer2 = NULL;
 605         struct hammer_blockmap_layer1 *layer1;
 606         struct hammer_blockmap_layer2 *layer2;
 607         hammer_off_t layer1_base;
 608         hammer_off_t layer1_offset;
 609         hammer_off_t layer2_offset;
 610         hammer_off_t phys_offset;
 611         hammer_off_t block_offset;
 612         hammer_off_t aligned_vol_free_end;
 613         hammer_blockmap_t freemap;
 614         int64_t count = 0;
 615         int64_t layer1_count = 0;
 616
 617         root_vol = get_root_volume();
 618         aligned_vol_free_end = (vol->vol_free_end + HAMMER_BLOCKMAP_LAYER2_MASK)
 619                                 & ~HAMMER_BLOCKMAP_LAYER2_MASK;
 620
 621         printf("initialize freemap volume %d\n", vol->vol_no);
 622
 623         /*
 624          * Initialize the freemap.  First preallocate the big-blocks required
 625          * to implement layer2.   This preallocation is a bootstrap allocation
 626          * using blocks from the target volume.
 627          */
 628         freemap = &root_vol->ondisk->vol0_blockmap[HAMMER_ZONE_FREEMAP_INDEX];
 629         layer1_base = freemap->phys_offset;
 630
 631         for (phys_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no, 0);
 632              phys_offset < aligned_vol_free_end;
 633              phys_offset += HAMMER_BLOCKMAP_LAYER2) {
 634                 layer1_offset = layer1_base +
 635                                 HAMMER_BLOCKMAP_LAYER1_OFFSET(phys_offset);
 636                 layer1 = get_buffer_data(layer1_offset, &buffer1, 0);
 637                 if (layer1->phys_offset == HAMMER_BLOCKMAP_UNAVAIL) {
 638                         layer1->phys_offset = alloc_bigblock(vol,
 639                                                 HAMMER_ZONE_FREEMAP_INDEX);
 640                         layer1->blocks_free = 0;
 641                         buffer1->cache.modified = 1;
 642                         layer1->layer1_crc = crc32(layer1,
 643                                                    HAMMER_LAYER1_CRCSIZE);
 644                 }
 645         }
 646
 647         /*
 648          * Now fill everything in.
 649          */
 650         for (phys_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no, 0);
 651              phys_offset < aligned_vol_free_end;
 652              phys_offset += HAMMER_BLOCKMAP_LAYER2) {
 653                 layer1_count = 0;
 654                 layer1_offset = layer1_base +
 655                                 HAMMER_BLOCKMAP_LAYER1_OFFSET(phys_offset);
 656                 layer1 = get_buffer_data(layer1_offset, &buffer1, 0);
 657                 assert(layer1->phys_offset != HAMMER_BLOCKMAP_UNAVAIL);
 658
 659                 for (block_offset = 0;
 660                      block_offset < HAMMER_BLOCKMAP_LAYER2;
 661                      block_offset += HAMMER_BIGBLOCK_SIZE) {
 662                         layer2_offset = layer1->phys_offset +
 663                                         HAMMER_BLOCKMAP_LAYER2_OFFSET(block_offset);
 664                         layer2 = get_buffer_data(layer2_offset, &buffer2, 0);
 665                         bzero(layer2, sizeof(*layer2));
 666
 667                         if (phys_offset + block_offset < vol->vol_free_off) {
 668                                 /*
 669                                  * Fixups XXX - big-blocks already allocated as part
 670                                  * of the freemap bootstrap.
 671                                  */
 672                                 if (layer2->zone == 0) {
 673                                         layer2->zone = HAMMER_ZONE_FREEMAP_INDEX;
 674                                         layer2->append_off = HAMMER_BIGBLOCK_SIZE;
 675                                         layer2->bytes_free = 0;
 676                                 }
 677                         } else if (phys_offset + block_offset < vol->vol_free_end) {
 678                                 layer2->zone = 0;
 679                                 layer2->append_off = 0;
 680                                 layer2->bytes_free = HAMMER_BIGBLOCK_SIZE;
 681                                 ++count;
 682                                 ++layer1_count;
 683                         } else {
 684                                 layer2->zone = HAMMER_ZONE_UNAVAIL_INDEX;
 685                                 layer2->append_off = HAMMER_BIGBLOCK_SIZE;
 686                                 layer2->bytes_free = 0;
 687                         }
 688                         layer2->entry_crc = crc32(layer2, HAMMER_LAYER2_CRCSIZE);
 689                         buffer2->cache.modified = 1;
 690                 }
 691
 692                 layer1->blocks_free += layer1_count;
 693                 layer1->layer1_crc = crc32(layer1, HAMMER_LAYER1_CRCSIZE);
 694                 buffer1->cache.modified = 1;
 695         }
 696
 697         rel_buffer(buffer1);
 698         rel_buffer(buffer2);
 699         rel_volume(root_vol);
 700         return(count);
 701 }
 702
 703 /*
 704  * Returns the number of big-blocks available for filesystem data and undos
 705  * without formatting.
 706  */
 707 int64_t
 708 count_freemap(struct volume_info *vol)
 709 {
 710         hammer_off_t phys_offset;
 711         hammer_off_t vol_free_off;
 712         hammer_off_t aligned_vol_free_end;
 713         int64_t count = 0;
 714
 715         vol_free_off = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no, 0);
 716         aligned_vol_free_end = (vol->vol_free_end + HAMMER_BLOCKMAP_LAYER2_MASK)
 717                                 & ~HAMMER_BLOCKMAP_LAYER2_MASK;
 718
 719         if (vol->vol_no == HAMMER_ROOT_VOLNO)
 720                 vol_free_off += HAMMER_BIGBLOCK_SIZE;
 721
 722         for (phys_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no, 0);
 723              phys_offset < aligned_vol_free_end;
 724              phys_offset += HAMMER_BLOCKMAP_LAYER2) {
 725                 vol_free_off += HAMMER_BIGBLOCK_SIZE;
 726         }
 727
 728         for (phys_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no, 0);
 729              phys_offset < aligned_vol_free_end;
 730              phys_offset += HAMMER_BIGBLOCK_SIZE) {
 731                 if (phys_offset < vol_free_off) {
 732                         ;
 733                 } else if (phys_offset < vol->vol_free_end) {
 734                         ++count;
 735                 }
 736         }
 737
 738         return(count);
 739 }
 740
 741 /*
 742  * Format the undomap for the root volume.
 743  */
 744 void
 745 format_undomap(struct volume_info *root_vol)
 746 {
 747         const int undo_zone = HAMMER_ZONE_UNDO_INDEX;
 748         hammer_off_t undo_limit;
 749         hammer_blockmap_t blockmap;
 750         struct hammer_volume_ondisk *ondisk;
 751         struct buffer_info *buffer = NULL;
 752         hammer_off_t scan;
 753         int n;
 754         int limit_index;
 755         uint32_t seqno;
 756
 757         /* Only root volume needs formatting */
 758         assert(root_vol->vol_no == HAMMER_ROOT_VOLNO);
 759         ondisk = root_vol->ondisk;
 760
 761         /*
 762          * Size the undo buffer in multiples of HAMMER_BIGBLOCK_SIZE,
 763          * up to HAMMER_UNDO_LAYER2 big-blocks.  Size to approximately
 764          * 0.1% of the disk.
 765          *
 766          * The minimum UNDO fifo size is 500MB, or approximately 1% of
 767          * the recommended 50G disk.
 768          *
 769          * Changing this minimum is rather dangerous as complex filesystem
 770          * operations can cause the UNDO FIFO to fill up otherwise.
 771          */
 772         undo_limit = UndoBufferSize;
 773         if (undo_limit == 0) {
 774                 undo_limit = (ondisk->vol_buf_end - ondisk->vol_buf_beg) / 1000;
 775                 if (undo_limit < 500*1024*1024)
 776                         undo_limit = 500*1024*1024;
 777         }
 778         undo_limit = (undo_limit + HAMMER_BIGBLOCK_MASK64) &
 779                      ~HAMMER_BIGBLOCK_MASK64;
 780         if (undo_limit < HAMMER_BIGBLOCK_SIZE)
 781                 undo_limit = HAMMER_BIGBLOCK_SIZE;
 782         if (undo_limit > HAMMER_BIGBLOCK_SIZE * HAMMER_UNDO_LAYER2)
 783                 undo_limit = HAMMER_BIGBLOCK_SIZE * HAMMER_UNDO_LAYER2;
 784         UndoBufferSize = undo_limit;
 785
 786         blockmap = &ondisk->vol0_blockmap[undo_zone];
 787         bzero(blockmap, sizeof(*blockmap));
 788         blockmap->phys_offset = HAMMER_BLOCKMAP_UNAVAIL;
 789         blockmap->first_offset = HAMMER_ZONE_ENCODE(undo_zone, 0);
 790         blockmap->next_offset = blockmap->first_offset;
 791         blockmap->alloc_offset = HAMMER_ZONE_ENCODE(undo_zone, undo_limit);
 792         blockmap->entry_crc = crc32(blockmap, HAMMER_BLOCKMAP_CRCSIZE);
 793
 794         limit_index = undo_limit / HAMMER_BIGBLOCK_SIZE;
 795         assert(limit_index <= HAMMER_UNDO_LAYER2);
 796
 797         for (n = 0; n < limit_index; ++n) {
 798                 ondisk->vol0_undo_array[n] = alloc_bigblock(NULL,
 799                                                         HAMMER_ZONE_UNDO_INDEX);
 800         }
 801         while (n < HAMMER_UNDO_LAYER2) {
 802                 ondisk->vol0_undo_array[n++] = HAMMER_BLOCKMAP_UNAVAIL;
 803         }
 804
 805         /*
 806          * Pre-initialize the UNDO blocks (HAMMER version 4+)
 807          */
 808         printf("initializing the undo map (%jd MB)\n",
 809                 (intmax_t)(blockmap->alloc_offset & HAMMER_OFF_LONG_MASK) /
 810                 (1024 * 1024));
 811
 812         scan = blockmap->first_offset;
 813         seqno = 0;
 814
 815         while (scan < blockmap->alloc_offset) {
 816                 hammer_fifo_head_t head;
 817                 hammer_fifo_tail_t tail;
 818                 int isnew;
 819                 int bytes = HAMMER_UNDO_ALIGN;
 820
 821                 isnew = ((scan & HAMMER_BUFMASK64) == 0);
 822                 head = get_buffer_data(scan, &buffer, isnew);
 823                 buffer->cache.modified = 1;
 824                 tail = (void *)((char *)head + bytes - sizeof(*tail));
 825
 826                 bzero(head, bytes);
 827                 head->hdr_signature = HAMMER_HEAD_SIGNATURE;
 828                 head->hdr_type = HAMMER_HEAD_TYPE_DUMMY;
 829                 head->hdr_size = bytes;
 830                 head->hdr_seq = seqno++;
 831
 832                 tail->tail_signature = HAMMER_TAIL_SIGNATURE;
 833                 tail->tail_type = HAMMER_HEAD_TYPE_DUMMY;
 834                 tail->tail_size = bytes;
 835
 836                 head->hdr_crc = crc32(head, HAMMER_FIFO_HEAD_CRCOFF) ^
 837                                 crc32(head + 1, bytes - sizeof(*head));
 838
 839                 scan += bytes;
 840         }
 841         rel_buffer(buffer);
 842 }
 843
 844 /*
 845  * Flush various tracking structures to disk
 846  */
 847 void
 848 flush_all_volumes(void)
 849 {
 850         struct volume_info *vol;
 851
 852         TAILQ_FOREACH(vol, &VolList, entry)
 853                 flush_volume(vol);
 854 }
 855
 856 void
 857 flush_volume(struct volume_info *volume)
 858 {
 859         struct buffer_info *buffer;
 860         int i;
 861
 862         for (i = 0; i < HAMMER_BUFLISTS; ++i) {
 863                 TAILQ_FOREACH(buffer, &volume->buffer_lists[i], entry)
 864                         flush_buffer(buffer);
 865         }
 866         if (writehammerbuf(volume, volume->ondisk, 0) == -1)
 867                 err(1, "Write volume %d (%s)", volume->vol_no, volume->name);
 868         volume->cache.modified = 0;
 869 }
 870
 871 void
 872 flush_buffer(struct buffer_info *buffer)
 873 {
 874         struct volume_info *vol;
 875
 876         vol = buffer->volume;
 877         if (writehammerbuf(vol, buffer->ondisk, buffer->raw_offset) == -1)
 878                 err(1, "Write volume %d (%s)", vol->vol_no, vol->name);
 879         buffer->cache.modified = 0;
 880 }
 881
 882 /*
 883  * Core I/O operations
 884  */
 885 static int
 886 readhammerbuf(struct volume_info *vol, void *data, int64_t offset)
 887 {
 888         ssize_t n;
 889
 890         n = pread(vol->fd, data, HAMMER_BUFSIZE, offset);
 891         if (n != HAMMER_BUFSIZE)
 892                 return(-1);
 893         return(0);
 894 }
 895
 896 static int
 897 writehammerbuf(struct volume_info *vol, const void *data, int64_t offset)
 898 {
 899         ssize_t n;
 900
 901         n = pwrite(vol->fd, data, HAMMER_BUFSIZE, offset);
 902         if (n != HAMMER_BUFSIZE)
 903                 return(-1);
 904         return(0);
 905 }
 906
 907 int64_t init_boot_area_size(int64_t value, off_t avg_vol_size)
 908 {
 909         if (value == 0) {
 910                 value = HAMMER_BOOT_NOMBYTES;
 911                 while (value > avg_vol_size / HAMMER_MAX_VOLUMES)
 912                         value >>= 1;
 913                 if (value < HAMMER_BOOT_MINBYTES)
 914                         value = 0;
 915         } else if (value < HAMMER_BOOT_MINBYTES) {
 916                 value = HAMMER_BOOT_MINBYTES;
 917         }
 918
 919         return(value);
 920 }
 921
 922 int64_t init_mem_area_size(int64_t value, off_t avg_vol_size)
 923 {
 924         if (value == 0) {
 925                 value = HAMMER_MEM_NOMBYTES;
 926                 while (value > avg_vol_size / HAMMER_MAX_VOLUMES)
 927                         value >>= 1;
 928                 if (value < HAMMER_MEM_MINBYTES)
 929                         value = 0;
 930         } else if (value < HAMMER_MEM_MINBYTES) {
 931                 value = HAMMER_MEM_MINBYTES;
 932         }
 933
 934         return(value);
 935 }