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/stat.h>
  36 #include <sys/diskslice.h>
  37 #include <sys/diskmbr.h>
  38 #include <assert.h>
  39 #include <stdio.h>
  40 #include <stdlib.h>
  41 #include <stdarg.h>
  42 #include <string.h>
  43 #include <unistd.h>
  44 #include <stddef.h>
  45 #include <err.h>
  46 #include <fcntl.h>
  47
  48 #include "hammer_util.h"
  49
  50 static void *alloc_blockmap(int zone, int bytes, hammer_off_t *result_offp,
  51                         struct buffer_info **bufferp);
  52 static hammer_off_t alloc_bigblock(struct volume_info *volume, int zone);
  53 static void get_buffer_readahead(struct buffer_info *base);
  54 static __inline void *get_ondisk(hammer_off_t buf_offset,
  55                         struct buffer_info **bufferp, int isnew);
  56 static int readhammerbuf(struct volume_info *vol, void *data, int64_t offset);
  57 static void writehammerbuf(struct volume_info *vol, const void *data,
  58                         int64_t offset);
  59
  60 int DebugOpt;
  61
  62 uuid_t Hammer_FSType;
  63 uuid_t Hammer_FSId;
  64 int64_t BootAreaSize;
  65 int64_t MemAreaSize;
  66 int64_t UndoBufferSize;
  67 int     UsingSuperClusters;
  68 int     NumVolumes;
  69 int     RootVolNo = -1;
  70 int     UseReadBehind = -4;
  71 int     UseReadAhead = 4;
  72 int     AssertOnFailure = 1;
  73 struct volume_list VolList = TAILQ_HEAD_INITIALIZER(VolList);
  74
  75 static __inline
  76 int
  77 buffer_hash(hammer_off_t buf_offset)
  78 {
  79         int hi;
  80
  81         hi = (int)(buf_offset / HAMMER_BUFSIZE) & HAMMER_BUFLISTMASK;
  82         return(hi);
  83 }
  84
  85 static struct buffer_info*
  86 find_buffer(struct volume_info *volume, hammer_off_t buf_offset)
  87 {
  88         int hi;
  89         struct buffer_info *buf;
  90
  91         hi = buffer_hash(buf_offset);
  92         TAILQ_FOREACH(buf, &volume->buffer_lists[hi], entry)
  93                 if (buf->buf_offset == buf_offset)
  94                         return(buf);
  95         return(NULL);
  96 }
  97
  98 /*
  99  * Lookup the requested information structure and related on-disk buffer.
 100  * Missing structures are created.
 101  */
 102 struct volume_info *
 103 setup_volume(int32_t vol_no, const char *filename, int isnew, int oflags)
 104 {
 105         struct volume_info *vol;
 106         struct volume_info *scan;
 107         struct hammer_volume_ondisk *ondisk;
 108         int i, n;
 109         struct stat st1, st2;
 110
 111         /*
 112          * Allocate the volume structure
 113          */
 114         vol = malloc(sizeof(*vol));
 115         bzero(vol, sizeof(*vol));
 116         for (i = 0; i < HAMMER_BUFLISTS; ++i)
 117                 TAILQ_INIT(&vol->buffer_lists[i]);
 118         vol->name = strdup(filename);
 119         vol->fd = open(vol->name, oflags);
 120         if (vol->fd < 0) {
 121                 err(1, "setup_volume: %s: Open failed", vol->name);
 122         }
 123
 124         /*
 125          * Read or initialize the volume header
 126          */
 127         vol->ondisk = ondisk = malloc(HAMMER_BUFSIZE);
 128         if (isnew > 0) {
 129                 bzero(ondisk, HAMMER_BUFSIZE);
 130         } else {
 131                 n = readhammerbuf(vol, ondisk, 0);
 132                 if (n == -1) {
 133                         err(1, "setup_volume: %s: Read failed at offset 0",
 134                             vol->name);
 135                 }
 136                 vol_no = ondisk->vol_no;
 137                 if (RootVolNo < 0) {
 138                         RootVolNo = ondisk->vol_rootvol;
 139                 } else if (RootVolNo != (int)ondisk->vol_rootvol) {
 140                         errx(1, "setup_volume: %s: root volume disagreement: "
 141                                 "%d vs %d",
 142                                 vol->name, RootVolNo, ondisk->vol_rootvol);
 143                 }
 144
 145                 if (bcmp(&Hammer_FSType, &ondisk->vol_fstype, sizeof(Hammer_FSType)) != 0) {
 146                         errx(1, "setup_volume: %s: Header does not indicate "
 147                                 "that this is a hammer volume", vol->name);
 148                 }
 149                 if (TAILQ_EMPTY(&VolList)) {
 150                         Hammer_FSId = vol->ondisk->vol_fsid;
 151                 } else if (bcmp(&Hammer_FSId, &ondisk->vol_fsid, sizeof(Hammer_FSId)) != 0) {
 152                         errx(1, "setup_volume: %s: FSId does match other "
 153                                 "volumes!", vol->name);
 154                 }
 155         }
 156         vol->vol_no = vol_no;
 157
 158         if (isnew > 0) {
 159                 vol->cache.modified = 1;
 160         }
 161
 162         if (fstat(vol->fd, &st1) != 0){
 163                 errx(1, "setup_volume: %s: Failed to stat", vol->name);
 164         }
 165
 166         /*
 167          * Link the volume structure in
 168          */
 169         TAILQ_FOREACH(scan, &VolList, entry) {
 170                 if (scan->vol_no == vol_no) {
 171                         errx(1, "setup_volume: %s: Duplicate volume number %d "
 172                                 "against %s", vol->name, vol_no, scan->name);
 173                 }
 174                 if (fstat(scan->fd, &st2) != 0){
 175                         errx(1, "setup_volume: %s: Failed to stat %s",
 176                                 vol->name, scan->name);
 177                 }
 178                 if ((st1.st_ino == st2.st_ino) && (st1.st_dev == st2.st_dev)) {
 179                         errx(1, "setup_volume: %s: Specified more than once",
 180                                 vol->name);
 181                 }
 182         }
 183         TAILQ_INSERT_TAIL(&VolList, vol, entry);
 184         return(vol);
 185 }
 186
 187 /*
 188  * Check basic volume characteristics.
 189  */
 190 void
 191 check_volume(struct volume_info *vol)
 192 {
 193         struct partinfo pinfo;
 194         struct stat st;
 195
 196         /*
 197          * Get basic information about the volume
 198          */
 199         if (ioctl(vol->fd, DIOCGPART, &pinfo) < 0) {
 200                 /*
 201                  * Allow the formatting of regular files as HAMMER volumes
 202                  */
 203                 if (fstat(vol->fd, &st) < 0)
 204                         err(1, "Unable to stat %s", vol->name);
 205                 vol->size = st.st_size;
 206                 vol->type = "REGFILE";
 207         } else {
 208                 /*
 209                  * When formatting a block device as a HAMMER volume the
 210                  * sector size must be compatible.  HAMMER uses 16384 byte
 211                  * filesystem buffers.
 212                  */
 213                 if (pinfo.reserved_blocks) {
 214                         errx(1, "HAMMER cannot be placed in a partition "
 215                                 "which overlaps the disklabel or MBR");
 216                 }
 217                 if (pinfo.media_blksize > HAMMER_BUFSIZE ||
 218                     HAMMER_BUFSIZE % pinfo.media_blksize) {
 219                         errx(1, "A media sector size of %d is not supported",
 220                              pinfo.media_blksize);
 221                 }
 222
 223                 vol->size = pinfo.media_size;
 224                 vol->device_offset = pinfo.media_offset;
 225                 vol->type = "DEVICE";
 226         }
 227
 228         /*
 229          * Reserve space for (future) header junk, setup our poor-man's
 230          * big-block allocator.
 231          */
 232         vol->vol_alloc = HAMMER_BUFSIZE * 16;
 233 }
 234
 235 struct volume_info *
 236 get_volume(int32_t vol_no)
 237 {
 238         struct volume_info *vol;
 239
 240         TAILQ_FOREACH(vol, &VolList, entry) {
 241                 if (vol->vol_no == vol_no)
 242                         break;
 243         }
 244         if (vol == NULL) {
 245                 if (AssertOnFailure)
 246                         errx(1, "get_volume: Volume %d does not exist!",
 247                                 vol_no);
 248                 return(NULL);
 249         }
 250         ++vol->cache.refs;
 251         /* not added to or removed from hammer cache */
 252         return(vol);
 253 }
 254
 255 void
 256 rel_volume(struct volume_info *volume)
 257 {
 258         if (volume == NULL)
 259                 return;
 260         /* not added to or removed from hammer cache */
 261         --volume->cache.refs;
 262 }
 263
 264 /*
 265  * Acquire the specified buffer.  isnew is -1 only when called
 266  * via get_buffer_readahead() to prevent another readahead.
 267  */
 268 struct buffer_info *
 269 get_buffer(hammer_off_t buf_offset, int isnew)
 270 {
 271         void *ondisk;
 272         struct buffer_info *buf;
 273         struct volume_info *volume;
 274         hammer_off_t orig_offset = buf_offset;
 275         int vol_no;
 276         int zone;
 277         int hi, n;
 278         int dora = 0;
 279
 280         zone = HAMMER_ZONE_DECODE(buf_offset);
 281         if (zone > HAMMER_ZONE_RAW_BUFFER_INDEX) {
 282                 buf_offset = blockmap_lookup(buf_offset, NULL, NULL, NULL);
 283         }
 284         if (buf_offset == HAMMER_OFF_BAD)
 285                 return(NULL);
 286
 287         if (AssertOnFailure) {
 288                 assert((buf_offset & HAMMER_OFF_ZONE_MASK) ==
 289                        HAMMER_ZONE_RAW_BUFFER);
 290         }
 291         vol_no = HAMMER_VOL_DECODE(buf_offset);
 292         volume = get_volume(vol_no);
 293         if (volume == NULL)
 294                 return(NULL);
 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: %016llx %016llx at %p\n",
 304                                 (long long)orig_offset, (long long)buf_offset,
 305                                 buf);
 306                 }
 307                 buf->buf_offset = buf_offset;
 308                 buf->raw_offset = volume->ondisk->vol_buf_beg +
 309                                   (buf_offset & HAMMER_OFF_SHORT_MASK);
 310                 buf->volume = volume;
 311                 hi = buffer_hash(buf_offset);
 312                 TAILQ_INSERT_TAIL(&volume->buffer_lists[hi], buf, entry);
 313                 ++volume->cache.refs;
 314                 buf->cache.u.buffer = buf;
 315                 hammer_cache_add(&buf->cache, ISBUFFER);
 316                 dora = (isnew == 0);
 317         } else {
 318                 if (DebugOpt > 1) {
 319                         fprintf(stderr, "get_buffer: %016llx %016llx at %p *\n",
 320                                 (long long)orig_offset, (long long)buf_offset,
 321                                 buf);
 322                 }
 323                 hammer_cache_used(&buf->cache);
 324                 ++buf->use_count;
 325         }
 326         ++buf->cache.refs;
 327         hammer_cache_flush();
 328         if ((ondisk = buf->ondisk) == NULL) {
 329                 buf->ondisk = ondisk = malloc(HAMMER_BUFSIZE);
 330                 if (isnew <= 0) {
 331                         n = readhammerbuf(volume, ondisk, buf->raw_offset);
 332                         if (n == -1) {
 333                                 if (AssertOnFailure)
 334                                         err(1, "get_buffer: %s:%016llx "
 335                                             "Read failed at offset %016llx",
 336                                             volume->name,
 337                                             (long long)buf->buf_offset,
 338                                             (long long)buf->raw_offset);
 339                                 bzero(ondisk, HAMMER_BUFSIZE);
 340                         }
 341                 }
 342         }
 343         if (isnew > 0) {
 344                 bzero(ondisk, HAMMER_BUFSIZE);
 345                 buf->cache.modified = 1;
 346         }
 347         if (dora)
 348                 get_buffer_readahead(buf);
 349         return(buf);
 350 }
 351
 352 static void
 353 get_buffer_readahead(struct buffer_info *base)
 354 {
 355         struct buffer_info *buf;
 356         struct volume_info *vol;
 357         hammer_off_t buf_offset;
 358         int64_t raw_offset;
 359         int ri = UseReadBehind;
 360         int re = UseReadAhead;
 361
 362         raw_offset = base->raw_offset + ri * HAMMER_BUFSIZE;
 363         vol = base->volume;
 364
 365         while (ri < re) {
 366                 if (raw_offset >= vol->ondisk->vol_buf_end)
 367                         break;
 368                 if (raw_offset < vol->ondisk->vol_buf_beg || ri == 0) {
 369                         ++ri;
 370                         raw_offset += HAMMER_BUFSIZE;
 371                         continue;
 372                 }
 373                 buf_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no,
 374                         raw_offset - vol->ondisk->vol_buf_beg);
 375                 buf = find_buffer(vol, buf_offset);
 376                 if (buf == NULL) {
 377                         buf = get_buffer(buf_offset, -1);
 378                         rel_buffer(buf);
 379                 }
 380                 ++ri;
 381                 raw_offset += HAMMER_BUFSIZE;
 382         }
 383 }
 384
 385 void
 386 rel_buffer(struct buffer_info *buffer)
 387 {
 388         struct volume_info *volume;
 389         int hi;
 390
 391         if (buffer == NULL)
 392                 return;
 393         assert(buffer->cache.refs > 0);
 394         if (--buffer->cache.refs == 0) {
 395                 if (buffer->cache.delete) {
 396                         hi = buffer_hash(buffer->buf_offset);
 397                         volume = buffer->volume;
 398                         if (buffer->cache.modified)
 399                                 flush_buffer(buffer);
 400                         TAILQ_REMOVE(&volume->buffer_lists[hi], buffer, entry);
 401                         hammer_cache_del(&buffer->cache);
 402                         free(buffer->ondisk);
 403                         free(buffer);
 404                         rel_volume(volume);
 405                 }
 406         }
 407 }
 408
 409 /*
 410  * Retrieve a pointer to a buffer data given a buffer offset.  The underlying
 411  * bufferp is freed if isnew or the offset is out of range of the cached data.
 412  * If bufferp is freed a referenced buffer is loaded into it.
 413  */
 414 void *
 415 get_buffer_data(hammer_off_t buf_offset, struct buffer_info **bufferp,
 416                 int isnew)
 417 {
 418         if (*bufferp != NULL) {
 419                 if (isnew > 0 ||
 420                     (((*bufferp)->buf_offset ^ buf_offset) & ~HAMMER_BUFMASK64)) {
 421                         rel_buffer(*bufferp);
 422                         *bufferp = NULL;
 423                 }
 424         }
 425         return(get_ondisk(buf_offset, bufferp, isnew));
 426 }
 427
 428 /*
 429  * Retrieve a pointer to a B-Tree node given a cluster offset.  The underlying
 430  * bufferp is freed if non-NULL and a referenced buffer is loaded into it.
 431  */
 432 hammer_node_ondisk_t
 433 get_node(hammer_off_t node_offset, struct buffer_info **bufferp)
 434 {
 435         if (*bufferp != NULL) {
 436                 rel_buffer(*bufferp);
 437                 *bufferp = NULL;
 438         }
 439         return(get_ondisk(node_offset, bufferp, 0));
 440 }
 441
 442 /*
 443  * Return a pointer to a buffer data given a buffer offset.
 444  * If *bufferp is NULL acquire the buffer otherwise use that buffer.
 445  */
 446 static __inline
 447 void *
 448 get_ondisk(hammer_off_t buf_offset, struct buffer_info **bufferp, int isnew)
 449 {
 450         struct buffer_info *buffer;
 451
 452         buffer = *bufferp;
 453         if (buffer == NULL) {
 454                 buffer = *bufferp = get_buffer(buf_offset, isnew);
 455                 if (buffer == NULL)
 456                         return(NULL);
 457         }
 458
 459         return((char *)buffer->ondisk +
 460                 ((int32_t)buf_offset & HAMMER_BUFMASK));
 461 }
 462
 463 /*
 464  * Allocate HAMMER elements - btree nodes, meta data, data storage
 465  */
 466 void *
 467 alloc_btree_element(hammer_off_t *offp, struct buffer_info **data_bufferp)
 468 {
 469         hammer_node_ondisk_t node;
 470
 471         node = alloc_blockmap(HAMMER_ZONE_BTREE_INDEX, sizeof(*node),
 472                               offp, data_bufferp);
 473         bzero(node, sizeof(*node));
 474         return (node);
 475 }
 476
 477 void *
 478 alloc_meta_element(hammer_off_t *offp, int32_t data_len,
 479                    struct buffer_info **data_bufferp)
 480 {
 481         void *data;
 482
 483         data = alloc_blockmap(HAMMER_ZONE_META_INDEX, data_len,
 484                               offp, data_bufferp);
 485         bzero(data, data_len);
 486         return (data);
 487 }
 488
 489 /*
 490  * The only data_len supported by HAMMER userspace for large data zone
 491  * (zone 10) is HAMMER_BUFSIZE which is 16KB.  >16KB data does not fit
 492  * in a buffer allocated by get_buffer().  Also alloc_blockmap() does
 493  * not consider >16KB buffer size.
 494  */
 495 void *
 496 alloc_data_element(hammer_off_t *offp, int32_t data_len,
 497                    struct buffer_info **data_bufferp)
 498 {
 499         void *data;
 500
 501         if (data_len >= HAMMER_BUFSIZE) {
 502                 assert(data_len == HAMMER_BUFSIZE); /* just one buffer */
 503                 data = alloc_blockmap(HAMMER_ZONE_LARGE_DATA_INDEX, data_len,
 504                                       offp, data_bufferp);
 505                 bzero(data, data_len);
 506         } else if (data_len) {
 507                 data = alloc_blockmap(HAMMER_ZONE_SMALL_DATA_INDEX, data_len,
 508                                       offp, data_bufferp);
 509                 bzero(data, data_len);
 510         } else {
 511                 data = NULL;
 512         }
 513         return (data);
 514 }
 515
 516 /*
 517  * Format a new freemap.  Set all layer1 entries to UNAVAIL.  The initialize
 518  * code will load each volume's freemap.
 519  */
 520 void
 521 format_freemap(struct volume_info *root_vol)
 522 {
 523         struct buffer_info *buffer = NULL;
 524         hammer_off_t layer1_offset;
 525         hammer_blockmap_t blockmap;
 526         struct hammer_blockmap_layer1 *layer1;
 527         int i, isnew;
 528
 529         /* Only root volume needs formatting */
 530         assert(root_vol->vol_no == RootVolNo);
 531
 532         layer1_offset = alloc_bigblock(root_vol, HAMMER_ZONE_FREEMAP_INDEX);
 533         for (i = 0; i < (int)HAMMER_BLOCKMAP_RADIX1; ++i) {
 534                 isnew = ((i % HAMMER_BLOCKMAP_RADIX1_PERBUFFER) == 0);
 535                 layer1 = get_buffer_data(layer1_offset + i * sizeof(*layer1),
 536                                          &buffer, isnew);
 537                 bzero(layer1, sizeof(*layer1));
 538                 layer1->phys_offset = HAMMER_BLOCKMAP_UNAVAIL;
 539                 layer1->blocks_free = 0;
 540                 layer1->layer1_crc = crc32(layer1, HAMMER_LAYER1_CRCSIZE);
 541         }
 542         rel_buffer(buffer);
 543
 544         blockmap = &root_vol->ondisk->vol0_blockmap[HAMMER_ZONE_FREEMAP_INDEX];
 545         bzero(blockmap, sizeof(*blockmap));
 546         blockmap->phys_offset = layer1_offset;
 547         blockmap->first_offset = 0;
 548         blockmap->next_offset = HAMMER_ENCODE_RAW_BUFFER(0, 0);
 549         blockmap->alloc_offset = HAMMER_ENCODE_RAW_BUFFER(255, -1);
 550         blockmap->entry_crc = crc32(blockmap, HAMMER_BLOCKMAP_CRCSIZE);
 551         root_vol->cache.modified = 1;
 552 }
 553
 554 /*
 555  * Load the volume's remaining free space into the freemap.
 556  *
 557  * Returns the number of big-blocks available.
 558  */
 559 int64_t
 560 initialize_freemap(struct volume_info *vol)
 561 {
 562         struct volume_info *root_vol;
 563         struct buffer_info *buffer1 = NULL;
 564         struct buffer_info *buffer2 = NULL;
 565         struct hammer_blockmap_layer1 *layer1;
 566         struct hammer_blockmap_layer2 *layer2;
 567         hammer_off_t layer1_base;
 568         hammer_off_t layer1_offset;
 569         hammer_off_t layer2_offset;
 570         hammer_off_t phys_offset;
 571         hammer_off_t block_offset;
 572         hammer_off_t aligned_vol_free_end;
 573         hammer_blockmap_t freemap;
 574         int64_t count = 0;
 575         int64_t layer1_count = 0;
 576
 577         root_vol = get_volume(RootVolNo);
 578         aligned_vol_free_end = (vol->vol_free_end + HAMMER_BLOCKMAP_LAYER2_MASK)
 579                                 & ~HAMMER_BLOCKMAP_LAYER2_MASK;
 580
 581         printf("initialize freemap volume %d\n", vol->vol_no);
 582
 583         /*
 584          * Initialize the freemap.  First preallocate the big-blocks required
 585          * to implement layer2.   This preallocation is a bootstrap allocation
 586          * using blocks from the target volume.
 587          */
 588         freemap = &root_vol->ondisk->vol0_blockmap[HAMMER_ZONE_FREEMAP_INDEX];
 589         layer1_base = freemap->phys_offset;
 590
 591         for (phys_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no, 0);
 592              phys_offset < aligned_vol_free_end;
 593              phys_offset += HAMMER_BLOCKMAP_LAYER2) {
 594                 layer1_offset = layer1_base +
 595                                 HAMMER_BLOCKMAP_LAYER1_OFFSET(phys_offset);
 596                 layer1 = get_buffer_data(layer1_offset, &buffer1, 0);
 597                 if (layer1->phys_offset == HAMMER_BLOCKMAP_UNAVAIL) {
 598                         layer1->phys_offset = alloc_bigblock(vol,
 599                                                 HAMMER_ZONE_FREEMAP_INDEX);
 600                         layer1->blocks_free = 0;
 601                         buffer1->cache.modified = 1;
 602                         layer1->layer1_crc = crc32(layer1,
 603                                                    HAMMER_LAYER1_CRCSIZE);
 604                 }
 605         }
 606
 607         /*
 608          * Now fill everything in.
 609          */
 610         for (phys_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no, 0);
 611              phys_offset < aligned_vol_free_end;
 612              phys_offset += HAMMER_BLOCKMAP_LAYER2) {
 613                 layer1_count = 0;
 614                 layer1_offset = layer1_base +
 615                                 HAMMER_BLOCKMAP_LAYER1_OFFSET(phys_offset);
 616                 layer1 = get_buffer_data(layer1_offset, &buffer1, 0);
 617                 assert(layer1->phys_offset != HAMMER_BLOCKMAP_UNAVAIL);
 618
 619                 for (block_offset = 0;
 620                      block_offset < HAMMER_BLOCKMAP_LAYER2;
 621                      block_offset += HAMMER_BIGBLOCK_SIZE) {
 622                         layer2_offset = layer1->phys_offset +
 623                                         HAMMER_BLOCKMAP_LAYER2_OFFSET(block_offset);
 624                         layer2 = get_buffer_data(layer2_offset, &buffer2, 0);
 625                         bzero(layer2, sizeof(*layer2));
 626
 627                         if (phys_offset + block_offset < vol->vol_free_off) {
 628                                 /*
 629                                  * Fixups XXX - big-blocks already allocated as part
 630                                  * of the freemap bootstrap.
 631                                  */
 632                                 if (layer2->zone == 0) {
 633                                         layer2->zone = HAMMER_ZONE_FREEMAP_INDEX;
 634                                         layer2->append_off = HAMMER_BIGBLOCK_SIZE;
 635                                         layer2->bytes_free = 0;
 636                                 }
 637                         } else if (phys_offset + block_offset < vol->vol_free_end) {
 638                                 layer2->zone = 0;
 639                                 layer2->append_off = 0;
 640                                 layer2->bytes_free = HAMMER_BIGBLOCK_SIZE;
 641                                 ++count;
 642                                 ++layer1_count;
 643                         } else {
 644                                 layer2->zone = HAMMER_ZONE_UNAVAIL_INDEX;
 645                                 layer2->append_off = HAMMER_BIGBLOCK_SIZE;
 646                                 layer2->bytes_free = 0;
 647                         }
 648                         layer2->entry_crc = crc32(layer2, HAMMER_LAYER2_CRCSIZE);
 649                         buffer2->cache.modified = 1;
 650                 }
 651
 652                 layer1->blocks_free += layer1_count;
 653                 layer1->layer1_crc = crc32(layer1, HAMMER_LAYER1_CRCSIZE);
 654                 buffer1->cache.modified = 1;
 655         }
 656
 657         rel_buffer(buffer1);
 658         rel_buffer(buffer2);
 659         rel_volume(root_vol);
 660         return(count);
 661 }
 662
 663 /*
 664  * Returns the number of big-blocks available for filesystem data and undos
 665  * without formatting.
 666  */
 667 int64_t
 668 count_freemap(struct volume_info *vol)
 669 {
 670         hammer_off_t phys_offset;
 671         hammer_off_t vol_free_off;
 672         hammer_off_t aligned_vol_free_end;
 673         int64_t count = 0;
 674
 675         vol_free_off = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no, 0);
 676         aligned_vol_free_end = (vol->vol_free_end + HAMMER_BLOCKMAP_LAYER2_MASK)
 677                                 & ~HAMMER_BLOCKMAP_LAYER2_MASK;
 678
 679         if (vol->vol_no == RootVolNo)
 680                 vol_free_off += HAMMER_BIGBLOCK_SIZE;
 681
 682         for (phys_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no, 0);
 683              phys_offset < aligned_vol_free_end;
 684              phys_offset += HAMMER_BLOCKMAP_LAYER2) {
 685                 vol_free_off += HAMMER_BIGBLOCK_SIZE;
 686         }
 687
 688         for (phys_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no, 0);
 689              phys_offset < aligned_vol_free_end;
 690              phys_offset += HAMMER_BIGBLOCK_SIZE) {
 691                 if (phys_offset < vol_free_off) {
 692                         ;
 693                 } else if (phys_offset < vol->vol_free_end) {
 694                         ++count;
 695                 }
 696         }
 697
 698         return(count);
 699 }
 700
 701 /*
 702  * Allocate big-blocks using our poor-man's volume->vol_free_off.
 703  *
 704  * If the zone is HAMMER_ZONE_FREEMAP_INDEX we are bootstrapping the freemap
 705  * itself and cannot update it yet.
 706  */
 707 hammer_off_t
 708 alloc_bigblock(struct volume_info *volume, int zone)
 709 {
 710         struct buffer_info *buffer1 = NULL;
 711         struct buffer_info *buffer2 = NULL;
 712         struct volume_info *root_vol;
 713         hammer_off_t result_offset;
 714         hammer_off_t layer_offset;
 715         hammer_blockmap_t freemap;
 716         struct hammer_blockmap_layer1 *layer1;
 717         struct hammer_blockmap_layer2 *layer2;
 718
 719         if (volume == NULL)
 720                 volume = get_volume(RootVolNo);
 721
 722         result_offset = volume->vol_free_off;
 723         if (result_offset >= volume->vol_free_end)
 724                 errx(1, "alloc_bigblock: Ran out of room, filesystem too small");
 725         volume->vol_free_off += HAMMER_BIGBLOCK_SIZE;
 726
 727         /*
 728          * Update the freemap.
 729          */
 730         if (zone != HAMMER_ZONE_FREEMAP_INDEX) {
 731                 root_vol = get_volume(RootVolNo);
 732                 freemap = &root_vol->ondisk->vol0_blockmap[HAMMER_ZONE_FREEMAP_INDEX];
 733                 layer_offset = freemap->phys_offset +
 734                                HAMMER_BLOCKMAP_LAYER1_OFFSET(result_offset);
 735                 layer1 = get_buffer_data(layer_offset, &buffer1, 0);
 736                 assert(layer1->phys_offset != HAMMER_BLOCKMAP_UNAVAIL);
 737                 --layer1->blocks_free;
 738                 layer1->layer1_crc = crc32(layer1, HAMMER_LAYER1_CRCSIZE);
 739                 buffer1->cache.modified = 1;
 740                 layer_offset = layer1->phys_offset +
 741                                HAMMER_BLOCKMAP_LAYER2_OFFSET(result_offset);
 742                 layer2 = get_buffer_data(layer_offset, &buffer2, 0);
 743                 assert(layer2->zone == 0);
 744                 layer2->zone = zone;
 745                 layer2->append_off = HAMMER_BIGBLOCK_SIZE;
 746                 layer2->bytes_free = 0;
 747                 layer2->entry_crc = crc32(layer2, HAMMER_LAYER2_CRCSIZE);
 748                 buffer2->cache.modified = 1;
 749
 750                 --root_vol->ondisk->vol0_stat_freebigblocks;
 751                 root_vol->cache.modified = 1;
 752
 753                 rel_buffer(buffer1);
 754                 rel_buffer(buffer2);
 755                 rel_volume(root_vol);
 756         }
 757
 758         rel_volume(volume);
 759         return(result_offset);
 760 }
 761
 762 /*
 763  * Format the undomap for the root volume.
 764  */
 765 void
 766 format_undomap(struct volume_info *root_vol)
 767 {
 768         const int undo_zone = HAMMER_ZONE_UNDO_INDEX;
 769         hammer_off_t undo_limit;
 770         hammer_blockmap_t blockmap;
 771         struct hammer_volume_ondisk *ondisk;
 772         struct buffer_info *buffer = NULL;
 773         hammer_off_t scan;
 774         int n;
 775         int limit_index;
 776         u_int32_t seqno;
 777
 778         /* Only root volume needs formatting */
 779         assert(root_vol->vol_no == RootVolNo);
 780         ondisk = root_vol->ondisk;
 781
 782         /*
 783          * Size the undo buffer in multiples of HAMMER_BIGBLOCK_SIZE,
 784          * up to HAMMER_UNDO_LAYER2 big-blocks.  Size to approximately
 785          * 0.1% of the disk.
 786          *
 787          * The minimum UNDO fifo size is 500MB, or approximately 1% of
 788          * the recommended 50G disk.
 789          *
 790          * Changing this minimum is rather dangerous as complex filesystem
 791          * operations can cause the UNDO FIFO to fill up otherwise.
 792          */
 793         undo_limit = UndoBufferSize;
 794         if (undo_limit == 0) {
 795                 undo_limit = (ondisk->vol_buf_end - ondisk->vol_buf_beg) / 1000;
 796                 if (undo_limit < 500*1024*1024)
 797                         undo_limit = 500*1024*1024;
 798         }
 799         undo_limit = (undo_limit + HAMMER_BIGBLOCK_MASK64) &
 800                      ~HAMMER_BIGBLOCK_MASK64;
 801         if (undo_limit < HAMMER_BIGBLOCK_SIZE)
 802                 undo_limit = HAMMER_BIGBLOCK_SIZE;
 803         if (undo_limit > HAMMER_BIGBLOCK_SIZE * HAMMER_UNDO_LAYER2)
 804                 undo_limit = HAMMER_BIGBLOCK_SIZE * HAMMER_UNDO_LAYER2;
 805         UndoBufferSize = undo_limit;
 806
 807         blockmap = &ondisk->vol0_blockmap[undo_zone];
 808         bzero(blockmap, sizeof(*blockmap));
 809         blockmap->phys_offset = HAMMER_BLOCKMAP_UNAVAIL;
 810         blockmap->first_offset = HAMMER_ZONE_ENCODE(undo_zone, 0);
 811         blockmap->next_offset = blockmap->first_offset;
 812         blockmap->alloc_offset = HAMMER_ZONE_ENCODE(undo_zone, undo_limit);
 813         blockmap->entry_crc = crc32(blockmap, HAMMER_BLOCKMAP_CRCSIZE);
 814
 815         limit_index = undo_limit / HAMMER_BIGBLOCK_SIZE;
 816         assert(limit_index <= HAMMER_UNDO_LAYER2);
 817
 818         for (n = 0; n < limit_index; ++n) {
 819                 ondisk->vol0_undo_array[n] = alloc_bigblock(NULL,
 820                                                         HAMMER_ZONE_UNDO_INDEX);
 821         }
 822         while (n < HAMMER_UNDO_LAYER2) {
 823                 ondisk->vol0_undo_array[n++] = HAMMER_BLOCKMAP_UNAVAIL;
 824         }
 825
 826         /*
 827          * Pre-initialize the UNDO blocks (HAMMER version 4+)
 828          */
 829         printf("initializing the undo map (%jd MB)\n",
 830                 (intmax_t)(blockmap->alloc_offset & HAMMER_OFF_LONG_MASK) /
 831                 (1024 * 1024));
 832
 833         scan = blockmap->first_offset;
 834         seqno = 0;
 835
 836         while (scan < blockmap->alloc_offset) {
 837                 hammer_fifo_head_t head;
 838                 hammer_fifo_tail_t tail;
 839                 int isnew;
 840                 int bytes = HAMMER_UNDO_ALIGN;
 841
 842                 isnew = ((scan & HAMMER_BUFMASK64) == 0);
 843                 head = get_buffer_data(scan, &buffer, isnew);
 844                 buffer->cache.modified = 1;
 845                 tail = (void *)((char *)head + bytes - sizeof(*tail));
 846
 847                 bzero(head, bytes);
 848                 head->hdr_signature = HAMMER_HEAD_SIGNATURE;
 849                 head->hdr_type = HAMMER_HEAD_TYPE_DUMMY;
 850                 head->hdr_size = bytes;
 851                 head->hdr_seq = seqno++;
 852
 853                 tail->tail_signature = HAMMER_TAIL_SIGNATURE;
 854                 tail->tail_type = HAMMER_HEAD_TYPE_DUMMY;
 855                 tail->tail_size = bytes;
 856
 857                 head->hdr_crc = crc32(head, HAMMER_FIFO_HEAD_CRCOFF) ^
 858                                 crc32(head + 1, bytes - sizeof(*head));
 859
 860                 scan += bytes;
 861         }
 862         rel_buffer(buffer);
 863 }
 864
 865 /*
 866  * Format a new blockmap.  This is mostly a degenerate case because
 867  * all allocations are now actually done from the freemap.
 868  */
 869 void
 870 format_blockmap(hammer_blockmap_t blockmap, int zone, hammer_off_t offset)
 871 {
 872         hammer_off_t zone_base = HAMMER_ZONE_ENCODE(zone, offset);
 873
 874         bzero(blockmap, sizeof(*blockmap));
 875         blockmap->phys_offset = 0;
 876         blockmap->first_offset = zone_base;
 877         blockmap->next_offset = zone_base;
 878         blockmap->alloc_offset = HAMMER_ENCODE(zone, 255, -1);
 879         blockmap->entry_crc = crc32(blockmap, HAMMER_BLOCKMAP_CRCSIZE);
 880 }
 881
 882 /*
 883  * Allocate a chunk of data out of a blockmap.  This is a simplified
 884  * version which uses next_offset as a simple allocation iterator.
 885  */
 886 static
 887 void *
 888 alloc_blockmap(int zone, int bytes, hammer_off_t *result_offp,
 889                struct buffer_info **bufferp)
 890 {
 891         struct buffer_info *buffer1 = NULL;
 892         struct buffer_info *buffer2 = NULL;
 893         struct volume_info *volume;
 894         hammer_blockmap_t blockmap;
 895         hammer_blockmap_t freemap;
 896         struct hammer_blockmap_layer1 *layer1;
 897         struct hammer_blockmap_layer2 *layer2;
 898         hammer_off_t layer1_offset;
 899         hammer_off_t layer2_offset;
 900         hammer_off_t chunk_offset;
 901         void *ptr;
 902
 903         volume = get_volume(RootVolNo);
 904
 905         blockmap = &volume->ondisk->vol0_blockmap[zone];
 906         freemap = &volume->ondisk->vol0_blockmap[HAMMER_ZONE_FREEMAP_INDEX];
 907         assert(HAMMER_ZONE_DECODE(blockmap->next_offset) == zone);
 908
 909         /*
 910          * Alignment and buffer-boundary issues.  If the allocation would
 911          * cross a buffer boundary we have to skip to the next buffer.
 912          */
 913         bytes = (bytes + 15) & ~15;
 914         assert(bytes > 0 && bytes <= HAMMER_BUFSIZE);  /* not HAMMER_XBUFSIZE */
 915         assert(zone >= HAMMER_ZONE2_MAPPED_INDEX && zone < HAMMER_MAX_ZONES);
 916
 917 again:
 918         assert(blockmap->next_offset != HAMMER_ZONE_ENCODE(zone + 1, 0));
 919
 920         if ((blockmap->next_offset ^ (blockmap->next_offset + bytes - 1)) &
 921             ~HAMMER_BUFMASK64) {
 922                 volume->cache.modified = 1;
 923                 blockmap->next_offset = (blockmap->next_offset + bytes - 1) &
 924                                         ~HAMMER_BUFMASK64;
 925         }
 926         chunk_offset = blockmap->next_offset & HAMMER_BIGBLOCK_MASK;
 927
 928         /*
 929          * Dive layer 1.
 930          */
 931         layer1_offset = freemap->phys_offset +
 932                         HAMMER_BLOCKMAP_LAYER1_OFFSET(blockmap->next_offset);
 933
 934         layer1 = get_buffer_data(layer1_offset, &buffer1, 0);
 935         assert(!(chunk_offset == 0 && layer1->blocks_free == 0));
 936
 937         if (layer1->phys_offset == HAMMER_BLOCKMAP_UNAVAIL) {
 938                 fprintf(stderr, "alloc_blockmap: ran out of space!\n");
 939                 exit(1);
 940         }
 941
 942         /*
 943          * Dive layer 2, each entry represents a big-block.
 944          */
 945         layer2_offset = layer1->phys_offset +
 946                         HAMMER_BLOCKMAP_LAYER2_OFFSET(blockmap->next_offset);
 947
 948         layer2 = get_buffer_data(layer2_offset, &buffer2, 0);
 949
 950         if (layer2->zone == HAMMER_ZONE_UNAVAIL_INDEX) {
 951                 fprintf(stderr, "alloc_blockmap: ran out of space!\n");
 952                 exit(1);
 953         }
 954
 955         /*
 956          * If we are entering a new big-block assign ownership to our
 957          * zone.  If the big-block is owned by another zone skip it.
 958          */
 959         if (layer2->zone == 0) {
 960                 --layer1->blocks_free;
 961                 layer1->layer1_crc = crc32(layer1, HAMMER_LAYER1_CRCSIZE);
 962                 layer2->zone = zone;
 963                 --volume->ondisk->vol0_stat_freebigblocks;
 964                 assert(layer2->bytes_free == HAMMER_BIGBLOCK_SIZE);
 965                 assert(layer2->append_off == 0);
 966         }
 967         if (layer2->zone != zone) {
 968                 volume->cache.modified = 1;
 969                 blockmap->next_offset = (blockmap->next_offset + HAMMER_BIGBLOCK_SIZE) &
 970                                         ~HAMMER_BIGBLOCK_MASK64;
 971                 goto again;
 972         }
 973
 974         buffer1->cache.modified = 1;
 975         buffer2->cache.modified = 1;
 976         volume->cache.modified = 1;
 977         assert(layer2->append_off == chunk_offset);
 978         layer2->bytes_free -= bytes;
 979         *result_offp = blockmap->next_offset;
 980         blockmap->next_offset += bytes;
 981         layer2->append_off = (int)blockmap->next_offset &
 982                               HAMMER_BIGBLOCK_MASK;
 983
 984         layer2->entry_crc = crc32(layer2, HAMMER_LAYER2_CRCSIZE);
 985
 986         ptr = get_buffer_data(*result_offp, bufferp, 0);
 987         (*bufferp)->cache.modified = 1;
 988
 989         rel_buffer(buffer1);
 990         rel_buffer(buffer2);
 991         rel_volume(volume);
 992         return(ptr);
 993 }
 994
 995 /*
 996  * Flush various tracking structures to disk
 997  */
 998 void
 999 flush_all_volumes(void)
1000 {
1001         struct volume_info *vol;
1002
1003         TAILQ_FOREACH(vol, &VolList, entry)
1004                 flush_volume(vol);
1005 }
1006
1007 void
1008 flush_volume(struct volume_info *volume)
1009 {
1010         struct buffer_info *buffer;
1011         int i;
1012
1013         for (i = 0; i < HAMMER_BUFLISTS; ++i) {
1014                 TAILQ_FOREACH(buffer, &volume->buffer_lists[i], entry)
1015                         flush_buffer(buffer);
1016         }
1017         writehammerbuf(volume, volume->ondisk, 0);
1018         volume->cache.modified = 0;
1019 }
1020
1021 void
1022 flush_buffer(struct buffer_info *buffer)
1023 {
1024         writehammerbuf(buffer->volume, buffer->ondisk, buffer->raw_offset);
1025         buffer->cache.modified = 0;
1026 }
1027
1028 /*
1029  * Core I/O operations
1030  */
1031 static int
1032 readhammerbuf(struct volume_info *vol, void *data, int64_t offset)
1033 {
1034         ssize_t n;
1035
1036         n = pread(vol->fd, data, HAMMER_BUFSIZE, offset);
1037         if (n != HAMMER_BUFSIZE)
1038                 return(-1);
1039         return(0);
1040 }
1041
1042 static void
1043 writehammerbuf(struct volume_info *vol, const void *data, int64_t offset)
1044 {
1045         ssize_t n;
1046
1047         n = pwrite(vol->fd, data, HAMMER_BUFSIZE, offset);
1048         if (n != HAMMER_BUFSIZE)
1049                 err(1, "Write volume %d (%s)", vol->vol_no, vol->name);
1050 }
1051
1052 int64_t init_boot_area_size(int64_t value, off_t avg_vol_size)
1053 {
1054         if (value == 0) {
1055                 value = HAMMER_BOOT_NOMBYTES;
1056                 while (value > avg_vol_size / HAMMER_MAX_VOLUMES)
1057                         value >>= 1;
1058                 if (value < HAMMER_BOOT_MINBYTES)
1059                         value = 0;
1060         } else if (value < HAMMER_BOOT_MINBYTES) {
1061                 value = HAMMER_BOOT_MINBYTES;
1062         }
1063
1064         return(value);
1065 }
1066
1067 int64_t init_mem_area_size(int64_t value, off_t avg_vol_size)
1068 {
1069         if (value == 0) {
1070                 value = HAMMER_MEM_NOMBYTES;
1071                 while (value > avg_vol_size / HAMMER_MAX_VOLUMES)
1072                         value >>= 1;
1073                 if (value < HAMMER_MEM_MINBYTES)
1074                         value = 0;
1075         } else if (value < HAMMER_MEM_MINBYTES) {
1076                 value = HAMMER_MEM_MINBYTES;
1077         }
1078
1079         return(value);
1080 }