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 check_volume(struct volume_info *vol);
  41 static void get_buffer_readahead(struct buffer_info *base);
  42 static __inline int readhammervol(struct volume_info *vol);
  43 static __inline int readhammerbuf(struct buffer_info *buf);
  44 static __inline int writehammervol(struct volume_info *vol);
  45 static __inline int writehammerbuf(struct buffer_info *buf);
  46
  47 uuid_t Hammer_FSType;
  48 uuid_t Hammer_FSId;
  49 int UseReadBehind = -4;
  50 int UseReadAhead = 4;
  51 int DebugOpt;
  52
  53 TAILQ_HEAD(volume_list, volume_info);
  54 static 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         check_volume(vol);
  99
 100         vol->ondisk = malloc(HAMMER_BUFSIZE);
 101         if (vol->ondisk == NULL)
 102                 err(1, "alloc_volume");
 103         bzero(vol->ondisk, HAMMER_BUFSIZE);
 104
 105         for (i = 0; i < HAMMER_BUFLISTS; ++i)
 106                 TAILQ_INIT(&vol->buffer_lists[i]);
 107
 108         return(vol);
 109 }
 110
 111 static void
 112 __add_volume(struct volume_info *vol)
 113 {
 114         struct volume_info *scan;
 115         struct stat st1, st2;
 116
 117         if (fstat(vol->fd, &st1) != 0)
 118                 errx(1, "add_volume: %s: Failed to stat", vol->name);
 119
 120         TAILQ_FOREACH(scan, &VolList, entry) {
 121                 if (scan->vol_no == vol->vol_no) {
 122                         errx(1, "add_volume: %s: Duplicate volume number %d "
 123                                 "against %s",
 124                                 vol->name, vol->vol_no, scan->name);
 125                 }
 126                 if (fstat(scan->fd, &st2) != 0) {
 127                         errx(1, "add_volume: %s: Failed to stat %s",
 128                                 vol->name, scan->name);
 129                 }
 130                 if ((st1.st_ino == st2.st_ino) && (st1.st_dev == st2.st_dev)) {
 131                         errx(1, "add_volume: %s: Specified more than once",
 132                                 vol->name);
 133                 }
 134         }
 135
 136         TAILQ_INSERT_TAIL(&VolList, vol, entry);
 137 }
 138
 139 /*
 140  * Initialize a volume structure and ondisk vol_no field.
 141  */
 142 struct volume_info *
 143 init_volume(int32_t vol_no, const char *filename, int oflags)
 144 {
 145         struct volume_info *vol;
 146
 147         vol = __alloc_volume(filename, oflags);
 148         vol->vol_no = vol->ondisk->vol_no = vol_no;
 149
 150         __add_volume(vol);
 151
 152         return(vol);
 153 }
 154
 155 /*
 156  * Initialize a volume structure and read ondisk volume header.
 157  */
 158 struct volume_info*
 159 load_volume(const char *filename, int oflags)
 160 {
 161         struct volume_info *vol;
 162         hammer_volume_ondisk_t ondisk;
 163         int n;
 164
 165         vol = __alloc_volume(filename, oflags);
 166
 167         n = readhammervol(vol);
 168         if (n == -1) {
 169                 err(1, "load_volume: %s: Read failed at offset 0", vol->name);
 170         }
 171         ondisk = vol->ondisk;
 172         vol->vol_no = ondisk->vol_no;
 173
 174         if (ondisk->vol_rootvol != HAMMER_ROOT_VOLNO) {
 175                 errx(1, "load_volume: Invalid root volume# %d",
 176                         ondisk->vol_rootvol);
 177         }
 178
 179         if (bcmp(&Hammer_FSType, &ondisk->vol_fstype, sizeof(Hammer_FSType))) {
 180                 errx(1, "load_volume: %s: Header does not indicate "
 181                         "that this is a hammer volume", vol->name);
 182         }
 183
 184         if (valid_hammer_volumes++ == 0) {
 185                 Hammer_FSId = ondisk->vol_fsid;
 186         } else if (bcmp(&Hammer_FSId, &ondisk->vol_fsid, sizeof(Hammer_FSId))) {
 187                 errx(1, "load_volume: %s: FSId does match other volumes!",
 188                         vol->name);
 189         }
 190
 191         __add_volume(vol);
 192
 193         return(vol);
 194 }
 195
 196 /*
 197  * Check basic volume characteristics.
 198  */
 199 static void
 200 check_volume(struct volume_info *vol)
 201 {
 202         struct partinfo pinfo;
 203         struct stat st;
 204
 205         /*
 206          * Get basic information about the volume
 207          */
 208         if (ioctl(vol->fd, DIOCGPART, &pinfo) < 0) {
 209                 /*
 210                  * Allow the formatting of regular files as HAMMER volumes
 211                  */
 212                 if (fstat(vol->fd, &st) < 0)
 213                         err(1, "Unable to stat %s", vol->name);
 214                 vol->size = st.st_size;
 215                 vol->type = "REGFILE";
 216         } else {
 217                 /*
 218                  * When formatting a block device as a HAMMER volume the
 219                  * sector size must be compatible.  HAMMER uses 16384 byte
 220                  * filesystem buffers.
 221                  */
 222                 if (pinfo.reserved_blocks) {
 223                         errx(1, "HAMMER cannot be placed in a partition "
 224                                 "which overlaps the disklabel or MBR");
 225                 }
 226                 if (pinfo.media_blksize > HAMMER_BUFSIZE ||
 227                     HAMMER_BUFSIZE % pinfo.media_blksize) {
 228                         errx(1, "A media sector size of %d is not supported",
 229                              pinfo.media_blksize);
 230                 }
 231
 232                 vol->size = pinfo.media_size;
 233                 vol->device_offset = pinfo.media_offset;
 234                 vol->type = "DEVICE";
 235         }
 236 }
 237
 238 void
 239 assert_volume_offset(struct volume_info *vol)
 240 {
 241         assert(hammer_is_zone_raw_buffer(vol->vol_free_off));
 242         assert(hammer_is_zone_raw_buffer(vol->vol_free_end));
 243 }
 244
 245 struct volume_info *
 246 get_volume(int32_t vol_no)
 247 {
 248         struct volume_info *vol;
 249
 250         TAILQ_FOREACH(vol, &VolList, entry) {
 251                 if (vol->vol_no == vol_no)
 252                         break;
 253         }
 254
 255         return(vol);
 256 }
 257
 258 struct volume_info *
 259 get_root_volume(void)
 260 {
 261         struct volume_info *root_vol;
 262
 263         root_vol = get_volume(HAMMER_ROOT_VOLNO);
 264         assert(root_vol != NULL);
 265
 266         return(root_vol);
 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 static struct buffer_info *
 274 get_buffer(hammer_off_t buf_offset, int isnew)
 275 {
 276         struct buffer_info *buf;
 277         struct volume_info *volume;
 278         int vol_no;
 279         int zone;
 280         int hi;
 281         int dora = 0;
 282         int error = 0;
 283
 284         zone = HAMMER_ZONE_DECODE(buf_offset);
 285         if (zone > HAMMER_ZONE_RAW_BUFFER_INDEX)
 286                 buf_offset = blockmap_lookup(buf_offset, NULL, NULL, &error);
 287         if (error || buf_offset == HAMMER_OFF_BAD)
 288                 return(NULL);
 289         assert(hammer_is_zone_raw_buffer(buf_offset));
 290
 291         vol_no = HAMMER_VOL_DECODE(buf_offset);
 292         volume = get_volume(vol_no);
 293         assert(volume != NULL);
 294
 295         buf_offset &= ~HAMMER_BUFMASK64;
 296         buf = find_buffer(volume, buf_offset);
 297
 298         if (buf == NULL) {
 299                 buf = malloc(sizeof(*buf));
 300                 bzero(buf, sizeof(*buf));
 301                 buf->buf_offset = buf_offset;
 302                 buf->raw_offset = hammer_xlate_to_phys(volume->ondisk,
 303                                                         buf_offset);
 304                 buf->volume = volume;
 305                 buf->ondisk = malloc(HAMMER_BUFSIZE);
 306                 if (isnew <= 0) {
 307                         if (readhammerbuf(buf) == -1) {
 308                                 err(1, "get_buffer: %s:%016jx "
 309                                     "Read failed at offset %016jx",
 310                                     volume->name,
 311                                     (intmax_t)buf->buf_offset,
 312                                     (intmax_t)buf->raw_offset);
 313                         }
 314                 }
 315
 316                 hi = buffer_hash(buf_offset);
 317                 TAILQ_INSERT_TAIL(&volume->buffer_lists[hi], buf, entry);
 318                 hammer_cache_add(&buf->cache);
 319                 dora = (isnew == 0);
 320         } else {
 321                 assert(buf->ondisk != NULL);
 322                 assert(isnew != -1);
 323                 hammer_cache_used(&buf->cache);
 324         }
 325
 326         ++buf->cache.refs;
 327         hammer_cache_flush();
 328
 329         if (isnew > 0) {
 330                 assert(buf->cache.modified == 0);
 331                 bzero(buf->ondisk, HAMMER_BUFSIZE);
 332                 buf->cache.modified = 1;
 333         }
 334         if (dora)
 335                 get_buffer_readahead(buf);
 336         return(buf);
 337 }
 338
 339 static void
 340 get_buffer_readahead(struct buffer_info *base)
 341 {
 342         struct buffer_info *buf;
 343         struct volume_info *vol;
 344         hammer_off_t buf_offset;
 345         int64_t raw_offset;
 346         int ri = UseReadBehind;
 347         int re = UseReadAhead;
 348
 349         raw_offset = base->raw_offset + ri * HAMMER_BUFSIZE;
 350         vol = base->volume;
 351
 352         while (ri < re) {
 353                 if (raw_offset >= vol->ondisk->vol_buf_end)
 354                         break;
 355                 if (raw_offset < vol->ondisk->vol_buf_beg || ri == 0) {
 356                         ++ri;
 357                         raw_offset += HAMMER_BUFSIZE;
 358                         continue;
 359                 }
 360                 buf_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no,
 361                         raw_offset - vol->ondisk->vol_buf_beg);
 362                 buf = find_buffer(vol, buf_offset);
 363                 if (buf == NULL) {
 364                         buf = get_buffer(buf_offset, -1);
 365                         rel_buffer(buf);
 366                 }
 367                 ++ri;
 368                 raw_offset += HAMMER_BUFSIZE;
 369         }
 370 }
 371
 372 void
 373 rel_buffer(struct buffer_info *buffer)
 374 {
 375         struct volume_info *volume;
 376         int hi;
 377
 378         if (buffer == NULL)
 379                 return;
 380         assert(buffer->cache.refs > 0);
 381         if (--buffer->cache.refs == 0) {
 382                 if (buffer->cache.delete) {
 383                         hi = buffer_hash(buffer->buf_offset);
 384                         volume = buffer->volume;
 385                         if (buffer->cache.modified)
 386                                 flush_buffer(buffer);
 387                         TAILQ_REMOVE(&volume->buffer_lists[hi], buffer, entry);
 388                         hammer_cache_del(&buffer->cache);
 389                         free(buffer->ondisk);
 390                         free(buffer);
 391                 }
 392         }
 393 }
 394
 395 /*
 396  * Retrieve a pointer to a buffer data given a buffer offset.  The underlying
 397  * bufferp is freed if isnew or the offset is out of range of the cached data.
 398  * If bufferp is freed a referenced buffer is loaded into it.
 399  */
 400 void *
 401 get_buffer_data(hammer_off_t buf_offset, struct buffer_info **bufferp,
 402                 int isnew)
 403 {
 404         if (*bufferp != NULL) {
 405                 if (isnew > 0 ||
 406                     (((*bufferp)->buf_offset ^ buf_offset) & ~HAMMER_BUFMASK64)) {
 407                         rel_buffer(*bufferp);
 408                         *bufferp = NULL;
 409                 }
 410         }
 411
 412         if (*bufferp == NULL) {
 413                 *bufferp = get_buffer(buf_offset, isnew);
 414                 if (*bufferp == NULL)
 415                         return(NULL);
 416         }
 417
 418         return(((char *)(*bufferp)->ondisk) +
 419                 ((int32_t)buf_offset & HAMMER_BUFMASK));
 420 }
 421
 422 /*
 423  * Allocate HAMMER elements - B-Tree nodes
 424  */
 425 hammer_node_ondisk_t
 426 alloc_btree_node(hammer_off_t *offp, struct buffer_info **data_bufferp)
 427 {
 428         hammer_node_ondisk_t node;
 429
 430         node = alloc_blockmap(HAMMER_ZONE_BTREE_INDEX, sizeof(*node),
 431                               offp, data_bufferp);
 432         bzero(node, sizeof(*node));
 433         return(node);
 434 }
 435
 436 /*
 437  * Allocate HAMMER elements - meta data (inode, direntry, PFS, etc)
 438  */
 439 void *
 440 alloc_meta_element(hammer_off_t *offp, int32_t data_len,
 441                    struct buffer_info **data_bufferp)
 442 {
 443         void *data;
 444
 445         data = alloc_blockmap(HAMMER_ZONE_META_INDEX, data_len,
 446                               offp, data_bufferp);
 447         bzero(data, data_len);
 448         return(data);
 449 }
 450
 451 /*
 452  * Allocate HAMMER elements - data storage
 453  *
 454  * The only data_len supported by HAMMER userspace for large data zone
 455  * (zone 10) is HAMMER_BUFSIZE which is 16KB.  >16KB data does not fit
 456  * in a buffer allocated by get_buffer().  Also alloc_blockmap() does
 457  * not consider >16KB buffer size.
 458  */
 459 void *
 460 alloc_data_element(hammer_off_t *offp, int32_t data_len,
 461                    struct buffer_info **data_bufferp)
 462 {
 463         void *data;
 464         int zone;
 465
 466         if (data_len == 0)
 467                 return(NULL);
 468
 469         zone = hammer_data_zone_index(data_len);
 470         assert(data_len <= HAMMER_BUFSIZE); /* just one buffer */
 471         assert(zone == HAMMER_ZONE_LARGE_DATA_INDEX ||
 472                zone == HAMMER_ZONE_SMALL_DATA_INDEX);
 473
 474         data = alloc_blockmap(zone, data_len, offp, data_bufferp);
 475         bzero(data, data_len);
 476         return(data);
 477 }
 478
 479 /*
 480  * Format a new blockmap.  This is mostly a degenerate case because
 481  * all allocations are now actually done from the freemap.
 482  */
 483 void
 484 format_blockmap(struct volume_info *root_vol, int zone, hammer_off_t offset)
 485 {
 486         hammer_blockmap_t blockmap;
 487         hammer_off_t zone_base;
 488
 489         /* Only root volume needs formatting */
 490         assert(root_vol->vol_no == HAMMER_ROOT_VOLNO);
 491
 492         assert(hammer_is_zone2_mapped_index(zone));
 493
 494         blockmap = &root_vol->ondisk->vol0_blockmap[zone];
 495         zone_base = HAMMER_ZONE_ENCODE(zone, offset);
 496
 497         bzero(blockmap, sizeof(*blockmap));
 498         blockmap->phys_offset = 0;
 499         blockmap->first_offset = zone_base;
 500         blockmap->next_offset = zone_base;
 501         blockmap->alloc_offset = HAMMER_ENCODE(zone, 255, -1);
 502         hammer_crc_set_blockmap(blockmap);
 503 }
 504
 505 /*
 506  * Format a new freemap.  Set all layer1 entries to UNAVAIL.  The initialize
 507  * code will load each volume's freemap.
 508  */
 509 void
 510 format_freemap(struct volume_info *root_vol)
 511 {
 512         struct buffer_info *buffer = NULL;
 513         hammer_off_t layer1_offset;
 514         hammer_blockmap_t blockmap;
 515         hammer_blockmap_layer1_t layer1;
 516         int i, isnew;
 517
 518         /* Only root volume needs formatting */
 519         assert(root_vol->vol_no == HAMMER_ROOT_VOLNO);
 520
 521         layer1_offset = alloc_bigblock(root_vol, HAMMER_ZONE_FREEMAP_INDEX);
 522         for (i = 0; i < HAMMER_BIGBLOCK_SIZE; i += sizeof(*layer1)) {
 523                 isnew = ((i % HAMMER_BUFSIZE) == 0);
 524                 layer1 = get_buffer_data(layer1_offset + i, &buffer, isnew);
 525                 bzero(layer1, sizeof(*layer1));
 526                 layer1->phys_offset = HAMMER_BLOCKMAP_UNAVAIL;
 527                 layer1->blocks_free = 0;
 528                 hammer_crc_set_layer1(layer1);
 529         }
 530         assert(i == HAMMER_BIGBLOCK_SIZE);
 531         rel_buffer(buffer);
 532
 533         blockmap = &root_vol->ondisk->vol0_blockmap[HAMMER_ZONE_FREEMAP_INDEX];
 534         bzero(blockmap, sizeof(*blockmap));
 535         blockmap->phys_offset = layer1_offset;
 536         blockmap->first_offset = 0;
 537         blockmap->next_offset = HAMMER_ENCODE_RAW_BUFFER(0, 0);
 538         blockmap->alloc_offset = HAMMER_ENCODE_RAW_BUFFER(255, -1);
 539         hammer_crc_set_blockmap(blockmap);
 540 }
 541
 542 /*
 543  * Load the volume's remaining free space into the freemap.
 544  *
 545  * Returns the number of big-blocks available.
 546  */
 547 int64_t
 548 initialize_freemap(struct volume_info *vol)
 549 {
 550         struct volume_info *root_vol;
 551         struct buffer_info *buffer1 = NULL;
 552         struct buffer_info *buffer2 = NULL;
 553         hammer_blockmap_layer1_t layer1;
 554         hammer_blockmap_layer2_t layer2;
 555         hammer_off_t layer1_offset;
 556         hammer_off_t layer2_offset;
 557         hammer_off_t phys_offset;
 558         hammer_off_t block_offset;
 559         hammer_off_t aligned_vol_free_end;
 560         hammer_blockmap_t freemap;
 561         int64_t count = 0;
 562         int64_t layer1_count = 0;
 563
 564         root_vol = get_root_volume();
 565
 566         assert_volume_offset(vol);
 567         aligned_vol_free_end = (vol->vol_free_end + HAMMER_BLOCKMAP_LAYER2_MASK)
 568                                 & ~HAMMER_BLOCKMAP_LAYER2_MASK;
 569
 570         printf("initialize freemap volume %d\n", vol->vol_no);
 571
 572         /*
 573          * Initialize the freemap.  First preallocate the big-blocks required
 574          * to implement layer2.   This preallocation is a bootstrap allocation
 575          * using blocks from the target volume.
 576          */
 577         freemap = &root_vol->ondisk->vol0_blockmap[HAMMER_ZONE_FREEMAP_INDEX];
 578
 579         for (phys_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no, 0);
 580              phys_offset < aligned_vol_free_end;
 581              phys_offset += HAMMER_BLOCKMAP_LAYER2) {
 582                 layer1_offset = freemap->phys_offset +
 583                                 HAMMER_BLOCKMAP_LAYER1_OFFSET(phys_offset);
 584                 layer1 = get_buffer_data(layer1_offset, &buffer1, 0);
 585                 if (layer1->phys_offset == HAMMER_BLOCKMAP_UNAVAIL) {
 586                         layer1->phys_offset = alloc_bigblock(vol,
 587                                                 HAMMER_ZONE_FREEMAP_INDEX);
 588                         layer1->blocks_free = 0;
 589                         buffer1->cache.modified = 1;
 590                         hammer_crc_set_layer1(layer1);
 591                 }
 592         }
 593
 594         /*
 595          * Now fill everything in.
 596          */
 597         for (phys_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no, 0);
 598              phys_offset < aligned_vol_free_end;
 599              phys_offset += HAMMER_BLOCKMAP_LAYER2) {
 600                 layer1_count = 0;
 601                 layer1_offset = freemap->phys_offset +
 602                                 HAMMER_BLOCKMAP_LAYER1_OFFSET(phys_offset);
 603                 layer1 = get_buffer_data(layer1_offset, &buffer1, 0);
 604                 assert(layer1->phys_offset != HAMMER_BLOCKMAP_UNAVAIL);
 605
 606                 for (block_offset = 0;
 607                      block_offset < HAMMER_BLOCKMAP_LAYER2;
 608                      block_offset += HAMMER_BIGBLOCK_SIZE) {
 609                         layer2_offset = layer1->phys_offset +
 610                                         HAMMER_BLOCKMAP_LAYER2_OFFSET(block_offset);
 611                         layer2 = get_buffer_data(layer2_offset, &buffer2, 0);
 612                         bzero(layer2, sizeof(*layer2));
 613
 614                         if (phys_offset + block_offset < vol->vol_free_off) {
 615                                 /*
 616                                  * Fixups XXX - big-blocks already allocated as part
 617                                  * of the freemap bootstrap.
 618                                  */
 619                                 layer2->zone = HAMMER_ZONE_FREEMAP_INDEX;
 620                                 layer2->append_off = HAMMER_BIGBLOCK_SIZE;
 621                                 layer2->bytes_free = 0;
 622                         } else if (phys_offset + block_offset < vol->vol_free_end) {
 623                                 layer2->zone = 0;
 624                                 layer2->append_off = 0;
 625                                 layer2->bytes_free = HAMMER_BIGBLOCK_SIZE;
 626                                 ++count;
 627                                 ++layer1_count;
 628                         } else {
 629                                 layer2->zone = HAMMER_ZONE_UNAVAIL_INDEX;
 630                                 layer2->append_off = HAMMER_BIGBLOCK_SIZE;
 631                                 layer2->bytes_free = 0;
 632                         }
 633                         hammer_crc_set_layer2(layer2);
 634                         buffer2->cache.modified = 1;
 635                 }
 636
 637                 layer1->blocks_free += layer1_count;
 638                 hammer_crc_set_layer1(layer1);
 639                 buffer1->cache.modified = 1;
 640         }
 641
 642         rel_buffer(buffer1);
 643         rel_buffer(buffer2);
 644         return(count);
 645 }
 646
 647 /*
 648  * Returns the number of big-blocks available for filesystem data and undos
 649  * without formatting.
 650  */
 651 int64_t
 652 count_freemap(struct volume_info *vol)
 653 {
 654         hammer_off_t phys_offset;
 655         hammer_off_t vol_free_off;
 656         hammer_off_t aligned_vol_free_end;
 657         int64_t count = 0;
 658
 659         vol_free_off = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no, 0);
 660
 661         assert_volume_offset(vol);
 662         aligned_vol_free_end = (vol->vol_free_end + HAMMER_BLOCKMAP_LAYER2_MASK)
 663                                 & ~HAMMER_BLOCKMAP_LAYER2_MASK;
 664
 665         if (vol->vol_no == HAMMER_ROOT_VOLNO)
 666                 vol_free_off += HAMMER_BIGBLOCK_SIZE;
 667
 668         for (phys_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no, 0);
 669              phys_offset < aligned_vol_free_end;
 670              phys_offset += HAMMER_BLOCKMAP_LAYER2) {
 671                 vol_free_off += HAMMER_BIGBLOCK_SIZE;
 672         }
 673
 674         for (phys_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no, 0);
 675              phys_offset < aligned_vol_free_end;
 676              phys_offset += HAMMER_BIGBLOCK_SIZE) {
 677                 if (phys_offset < vol_free_off) {
 678                         ;
 679                 } else if (phys_offset < vol->vol_free_end) {
 680                         ++count;
 681                 }
 682         }
 683
 684         return(count);
 685 }
 686
 687 /*
 688  * Format the undomap for the root volume.
 689  */
 690 void
 691 format_undomap(struct volume_info *root_vol, int64_t *undo_buffer_size)
 692 {
 693         const int undo_zone = HAMMER_ZONE_UNDO_INDEX;
 694         hammer_off_t undo_limit;
 695         hammer_blockmap_t blockmap;
 696         hammer_volume_ondisk_t ondisk;
 697         struct buffer_info *buffer = NULL;
 698         hammer_off_t scan;
 699         int n;
 700         int limit_index;
 701         uint32_t seqno;
 702
 703         /* Only root volume needs formatting */
 704         assert(root_vol->vol_no == HAMMER_ROOT_VOLNO);
 705         ondisk = root_vol->ondisk;
 706
 707         /*
 708          * Size the undo buffer in multiples of HAMMER_BIGBLOCK_SIZE,
 709          * up to HAMMER_UNDO_LAYER2 big-blocks.  Size to approximately
 710          * 0.1% of the disk.
 711          *
 712          * The minimum UNDO fifo size is 500MB, or approximately 1% of
 713          * the recommended 50G disk.
 714          *
 715          * Changing this minimum is rather dangerous as complex filesystem
 716          * operations can cause the UNDO FIFO to fill up otherwise.
 717          */
 718         undo_limit = *undo_buffer_size;
 719         if (undo_limit == 0) {
 720                 undo_limit = HAMMER_VOL_BUF_SIZE(ondisk) / 1000;
 721                 if (undo_limit < 500*1024*1024)
 722                         undo_limit = 500*1024*1024;
 723         }
 724         undo_limit = (undo_limit + HAMMER_BIGBLOCK_MASK64) &
 725                      ~HAMMER_BIGBLOCK_MASK64;
 726         if (undo_limit < HAMMER_BIGBLOCK_SIZE)
 727                 undo_limit = HAMMER_BIGBLOCK_SIZE;
 728         if (undo_limit > HAMMER_BIGBLOCK_SIZE * HAMMER_UNDO_LAYER2)
 729                 undo_limit = HAMMER_BIGBLOCK_SIZE * HAMMER_UNDO_LAYER2;
 730         *undo_buffer_size = undo_limit;
 731
 732         blockmap = &ondisk->vol0_blockmap[undo_zone];
 733         bzero(blockmap, sizeof(*blockmap));
 734         blockmap->phys_offset = HAMMER_BLOCKMAP_UNAVAIL;
 735         blockmap->first_offset = HAMMER_ZONE_ENCODE(undo_zone, 0);
 736         blockmap->next_offset = blockmap->first_offset;
 737         blockmap->alloc_offset = HAMMER_ZONE_ENCODE(undo_zone, undo_limit);
 738         hammer_crc_set_blockmap(blockmap);
 739
 740         limit_index = undo_limit / HAMMER_BIGBLOCK_SIZE;
 741         assert(limit_index <= HAMMER_UNDO_LAYER2);
 742
 743         for (n = 0; n < limit_index; ++n) {
 744                 ondisk->vol0_undo_array[n] = alloc_bigblock(root_vol,
 745                                                         HAMMER_ZONE_UNDO_INDEX);
 746         }
 747         while (n < HAMMER_UNDO_LAYER2) {
 748                 ondisk->vol0_undo_array[n++] = HAMMER_BLOCKMAP_UNAVAIL;
 749         }
 750
 751         /*
 752          * Pre-initialize the UNDO blocks (HAMMER version 4+)
 753          */
 754         printf("initializing the undo map (%jd MB)\n",
 755                 (intmax_t)(blockmap->alloc_offset & HAMMER_OFF_LONG_MASK) /
 756                 (1024 * 1024));
 757
 758         scan = blockmap->first_offset;
 759         seqno = 0;
 760
 761         while (scan < blockmap->alloc_offset) {
 762                 hammer_fifo_head_t head;
 763                 hammer_fifo_tail_t tail;
 764                 int isnew;
 765                 int bytes = HAMMER_UNDO_ALIGN;
 766
 767                 isnew = ((scan & HAMMER_BUFMASK64) == 0);
 768                 head = get_buffer_data(scan, &buffer, isnew);
 769                 buffer->cache.modified = 1;
 770                 tail = (void *)((char *)head + bytes - sizeof(*tail));
 771
 772                 bzero(head, bytes);
 773                 head->hdr_signature = HAMMER_HEAD_SIGNATURE;
 774                 head->hdr_type = HAMMER_HEAD_TYPE_DUMMY;
 775                 head->hdr_size = bytes;
 776                 head->hdr_seq = seqno++;
 777
 778                 tail->tail_signature = HAMMER_TAIL_SIGNATURE;
 779                 tail->tail_type = HAMMER_HEAD_TYPE_DUMMY;
 780                 tail->tail_size = bytes;
 781
 782                 hammer_crc_set_fifo_head(head, bytes);
 783
 784                 scan += bytes;
 785         }
 786         rel_buffer(buffer);
 787 }
 788
 789 const char *zone_labels[] = {
 790         "",             /* 0 */
 791         "raw_volume",   /* 1 */
 792         "raw_buffer",   /* 2 */
 793         "undo",         /* 3 */
 794         "freemap",      /* 4 */
 795         "",             /* 5 */
 796         "",             /* 6 */
 797         "",             /* 7 */
 798         "btree",        /* 8 */
 799         "meta",         /* 9 */
 800         "large_data",   /* 10 */
 801         "small_data",   /* 11 */
 802         "",             /* 12 */
 803         "",             /* 13 */
 804         "",             /* 14 */
 805         "unavail",      /* 15 */
 806 };
 807
 808 void
 809 print_blockmap(const struct volume_info *root_vol)
 810 {
 811         hammer_blockmap_t blockmap;
 812         hammer_volume_ondisk_t ondisk;
 813         int64_t size, used;
 814         int i;
 815 #define INDENT ""
 816
 817         ondisk = root_vol->ondisk;
 818         printf(INDENT"vol_label\t%s\n", ondisk->vol_label);
 819         printf(INDENT"vol_count\t%d\n", ondisk->vol_count);
 820         printf(INDENT"vol_bot_beg\t%s\n", sizetostr(ondisk->vol_bot_beg));
 821         printf(INDENT"vol_mem_beg\t%s\n", sizetostr(ondisk->vol_mem_beg));
 822         printf(INDENT"vol_buf_beg\t%s\n", sizetostr(ondisk->vol_buf_beg));
 823         printf(INDENT"vol_buf_end\t%s\n", sizetostr(ondisk->vol_buf_end));
 824         printf(INDENT"vol0_next_tid\t%016jx\n",
 825                (uintmax_t)ondisk->vol0_next_tid);
 826
 827         blockmap = &ondisk->vol0_blockmap[HAMMER_ZONE_UNDO_INDEX];
 828         size = blockmap->alloc_offset & HAMMER_OFF_LONG_MASK;
 829         if (blockmap->first_offset <= blockmap->next_offset)
 830                 used = blockmap->next_offset - blockmap->first_offset;
 831         else
 832                 used = blockmap->alloc_offset - blockmap->first_offset +
 833                         (blockmap->next_offset & HAMMER_OFF_LONG_MASK);
 834         printf(INDENT"undo_size\t%s\n", sizetostr(size));
 835         printf(INDENT"undo_used\t%s\n", sizetostr(used));
 836
 837         printf(INDENT"zone #             "
 838                "phys             first            next             alloc\n");
 839         for (i = 0; i < HAMMER_MAX_ZONES; i++) {
 840                 blockmap = &ondisk->vol0_blockmap[i];
 841                 printf(INDENT"zone %-2d %-10s %016jx %016jx %016jx %016jx\n",
 842                         i, zone_labels[i],
 843                         (uintmax_t)blockmap->phys_offset,
 844                         (uintmax_t)blockmap->first_offset,
 845                         (uintmax_t)blockmap->next_offset,
 846                         (uintmax_t)blockmap->alloc_offset);
 847         }
 848 }
 849
 850 /*
 851  * Flush various tracking structures to disk
 852  */
 853 void
 854 flush_all_volumes(void)
 855 {
 856         struct volume_info *vol;
 857
 858         TAILQ_FOREACH(vol, &VolList, entry)
 859                 flush_volume(vol);
 860 }
 861
 862 void
 863 flush_volume(struct volume_info *volume)
 864 {
 865         struct buffer_info *buffer;
 866         int i;
 867
 868         for (i = 0; i < HAMMER_BUFLISTS; ++i) {
 869                 TAILQ_FOREACH(buffer, &volume->buffer_lists[i], entry)
 870                         flush_buffer(buffer);
 871         }
 872         if (writehammervol(volume) == -1)
 873                 err(1, "Write volume %d (%s)", volume->vol_no, volume->name);
 874 }
 875
 876 void
 877 flush_buffer(struct buffer_info *buffer)
 878 {
 879         struct volume_info *vol;
 880
 881         vol = buffer->volume;
 882         if (writehammerbuf(buffer) == -1)
 883                 err(1, "Write volume %d (%s)", vol->vol_no, vol->name);
 884         buffer->cache.modified = 0;
 885 }
 886
 887 /*
 888  * Core I/O operations
 889  */
 890 static int
 891 __read(struct volume_info *vol, void *data, int64_t offset, int size)
 892 {
 893         ssize_t n;
 894
 895         n = pread(vol->fd, data, size, offset);
 896         if (n != size)
 897                 return(-1);
 898         return(0);
 899 }
 900
 901 static __inline int
 902 readhammervol(struct volume_info *vol)
 903 {
 904         return(__read(vol, vol->ondisk, 0, HAMMER_BUFSIZE));
 905 }
 906
 907 static __inline int
 908 readhammerbuf(struct buffer_info *buf)
 909 {
 910         return(__read(buf->volume, buf->ondisk, buf->raw_offset, HAMMER_BUFSIZE));
 911 }
 912
 913 static int
 914 __write(struct volume_info *vol, const void *data, int64_t offset, int size)
 915 {
 916         ssize_t n;
 917
 918         if (vol->rdonly)
 919                 return(0);
 920
 921         n = pwrite(vol->fd, data, size, offset);
 922         if (n != size)
 923                 return(-1);
 924         return(0);
 925 }
 926
 927 static __inline int
 928 writehammervol(struct volume_info *vol)
 929 {
 930         return(__write(vol, vol->ondisk, 0, HAMMER_BUFSIZE));
 931 }
 932
 933 static __inline int
 934 writehammerbuf(struct buffer_info *buf)
 935 {
 936         return(__write(buf->volume, buf->ondisk, buf->raw_offset, HAMMER_BUFSIZE));
 937 }
 938
 939 int64_t init_boot_area_size(int64_t value, off_t avg_vol_size)
 940 {
 941         if (value == 0) {
 942                 value = HAMMER_BOOT_NOMBYTES;
 943                 while (value > avg_vol_size / HAMMER_MAX_VOLUMES)
 944                         value >>= 1;
 945                 if (value < HAMMER_BOOT_MINBYTES)
 946                         value = 0;
 947         } else if (value < HAMMER_BOOT_MINBYTES) {
 948                 value = HAMMER_BOOT_MINBYTES;
 949         }
 950
 951         return(value);
 952 }
 953
 954 int64_t init_mem_area_size(int64_t value, off_t avg_vol_size)
 955 {
 956         if (value == 0) {
 957                 value = HAMMER_MEM_NOMBYTES;
 958                 while (value > avg_vol_size / HAMMER_MAX_VOLUMES)
 959                         value >>= 1;
 960                 if (value < HAMMER_MEM_MINBYTES)
 961                         value = 0;
 962         } else if (value < HAMMER_MEM_MINBYTES) {
 963                 value = HAMMER_MEM_MINBYTES;
 964         }
 965
 966         return(value);
 967 }