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     RootVolNo = -1;
  55 int     UseReadBehind = -4;
  56 int     UseReadAhead = 4;
  57 int     AssertOnFailure = 1;
  58 struct volume_list VolList = TAILQ_HEAD_INITIALIZER(VolList);
  59
  60 static __inline
  61 int
  62 buffer_hash(hammer_off_t buf_offset)
  63 {
  64         int hi;
  65
  66         hi = (int)(buf_offset / HAMMER_BUFSIZE) & HAMMER_BUFLISTMASK;
  67         return(hi);
  68 }
  69
  70 static struct buffer_info*
  71 find_buffer(struct volume_info *volume, hammer_off_t buf_offset)
  72 {
  73         int hi;
  74         struct buffer_info *buf;
  75
  76         hi = buffer_hash(buf_offset);
  77         TAILQ_FOREACH(buf, &volume->buffer_lists[hi], entry)
  78                 if (buf->buf_offset == buf_offset)
  79                         return(buf);
  80         return(NULL);
  81 }
  82
  83 /*
  84  * Lookup the requested information structure and related on-disk buffer.
  85  * Missing structures are created.
  86  */
  87 struct volume_info *
  88 setup_volume(int32_t vol_no, const char *filename, int isnew, int oflags)
  89 {
  90         struct volume_info *vol;
  91         struct volume_info *scan;
  92         struct hammer_volume_ondisk *ondisk;
  93         int i, n;
  94         struct stat st1, st2;
  95
  96         /*
  97          * Allocate the volume structure
  98          */
  99         vol = malloc(sizeof(*vol));
 100         bzero(vol, sizeof(*vol));
 101         for (i = 0; i < HAMMER_BUFLISTS; ++i)
 102                 TAILQ_INIT(&vol->buffer_lists[i]);
 103         vol->name = strdup(filename);
 104         vol->fd = open(vol->name, oflags);
 105         if (vol->fd < 0) {
 106                 err(1, "setup_volume: %s: Open failed", vol->name);
 107         }
 108
 109         /*
 110          * Read or initialize the volume header
 111          */
 112         vol->ondisk = ondisk = malloc(HAMMER_BUFSIZE);
 113         if (isnew > 0) {
 114                 bzero(ondisk, HAMMER_BUFSIZE);
 115         } else {
 116                 n = readhammerbuf(vol, ondisk, 0);
 117                 if (n == -1) {
 118                         err(1, "setup_volume: %s: Read failed at offset 0",
 119                             vol->name);
 120                 }
 121                 vol_no = ondisk->vol_no;
 122                 if (RootVolNo < 0) {
 123                         RootVolNo = ondisk->vol_rootvol;
 124                 } else if (RootVolNo != (int)ondisk->vol_rootvol) {
 125                         errx(1, "setup_volume: %s: root volume disagreement: "
 126                                 "%d vs %d",
 127                                 vol->name, RootVolNo, ondisk->vol_rootvol);
 128                 }
 129
 130                 if (bcmp(&Hammer_FSType, &ondisk->vol_fstype, sizeof(Hammer_FSType)) != 0) {
 131                         errx(1, "setup_volume: %s: Header does not indicate "
 132                                 "that this is a hammer volume", vol->name);
 133                 }
 134                 if (TAILQ_EMPTY(&VolList)) {
 135                         Hammer_FSId = vol->ondisk->vol_fsid;
 136                 } else if (bcmp(&Hammer_FSId, &ondisk->vol_fsid, sizeof(Hammer_FSId)) != 0) {
 137                         errx(1, "setup_volume: %s: FSId does match other "
 138                                 "volumes!", vol->name);
 139                 }
 140         }
 141         vol->vol_no = vol_no;
 142
 143         if (isnew > 0) {
 144                 vol->cache.modified = 1;
 145         }
 146
 147         if (fstat(vol->fd, &st1) != 0){
 148                 errx(1, "setup_volume: %s: Failed to stat", vol->name);
 149         }
 150
 151         /*
 152          * Link the volume structure in
 153          */
 154         TAILQ_FOREACH(scan, &VolList, entry) {
 155                 if (scan->vol_no == vol_no) {
 156                         errx(1, "setup_volume: %s: Duplicate volume number %d "
 157                                 "against %s", vol->name, vol_no, scan->name);
 158                 }
 159                 if (fstat(scan->fd, &st2) != 0){
 160                         errx(1, "setup_volume: %s: Failed to stat %s",
 161                                 vol->name, scan->name);
 162                 }
 163                 if ((st1.st_ino == st2.st_ino) && (st1.st_dev == st2.st_dev)) {
 164                         errx(1, "setup_volume: %s: Specified more than once",
 165                                 vol->name);
 166                 }
 167         }
 168         TAILQ_INSERT_TAIL(&VolList, vol, entry);
 169         return(vol);
 170 }
 171
 172 /*
 173  * Check basic volume characteristics.
 174  */
 175 void
 176 check_volume(struct volume_info *vol)
 177 {
 178         struct partinfo pinfo;
 179         struct stat st;
 180
 181         /*
 182          * Get basic information about the volume
 183          */
 184         if (ioctl(vol->fd, DIOCGPART, &pinfo) < 0) {
 185                 /*
 186                  * Allow the formatting of regular files as HAMMER volumes
 187                  */
 188                 if (fstat(vol->fd, &st) < 0)
 189                         err(1, "Unable to stat %s", vol->name);
 190                 vol->size = st.st_size;
 191                 vol->type = "REGFILE";
 192         } else {
 193                 /*
 194                  * When formatting a block device as a HAMMER volume the
 195                  * sector size must be compatible.  HAMMER uses 16384 byte
 196                  * filesystem buffers.
 197                  */
 198                 if (pinfo.reserved_blocks) {
 199                         errx(1, "HAMMER cannot be placed in a partition "
 200                                 "which overlaps the disklabel or MBR");
 201                 }
 202                 if (pinfo.media_blksize > HAMMER_BUFSIZE ||
 203                     HAMMER_BUFSIZE % pinfo.media_blksize) {
 204                         errx(1, "A media sector size of %d is not supported",
 205                              pinfo.media_blksize);
 206                 }
 207
 208                 vol->size = pinfo.media_size;
 209                 vol->device_offset = pinfo.media_offset;
 210                 vol->type = "DEVICE";
 211         }
 212 }
 213
 214 struct volume_info *
 215 get_volume(int32_t vol_no)
 216 {
 217         struct volume_info *vol;
 218
 219         TAILQ_FOREACH(vol, &VolList, entry) {
 220                 if (vol->vol_no == vol_no)
 221                         break;
 222         }
 223         if (vol == NULL) {
 224                 if (AssertOnFailure)
 225                         errx(1, "get_volume: Volume %d does not exist!",
 226                                 vol_no);
 227                 return(NULL);
 228         }
 229         ++vol->cache.refs;
 230         /* not added to or removed from hammer cache */
 231         return(vol);
 232 }
 233
 234 void
 235 rel_volume(struct volume_info *volume)
 236 {
 237         if (volume == NULL)
 238                 return;
 239         /* not added to or removed from hammer cache */
 240         --volume->cache.refs;
 241 }
 242
 243 /*
 244  * Acquire the specified buffer.  isnew is -1 only when called
 245  * via get_buffer_readahead() to prevent another readahead.
 246  */
 247 struct buffer_info *
 248 get_buffer(hammer_off_t buf_offset, int isnew)
 249 {
 250         void *ondisk;
 251         struct buffer_info *buf;
 252         struct volume_info *volume;
 253         hammer_off_t orig_offset = buf_offset;
 254         int vol_no;
 255         int zone;
 256         int hi, n;
 257         int dora = 0;
 258
 259         zone = HAMMER_ZONE_DECODE(buf_offset);
 260         if (zone > HAMMER_ZONE_RAW_BUFFER_INDEX) {
 261                 buf_offset = blockmap_lookup(buf_offset, NULL, NULL, NULL);
 262         }
 263         if (buf_offset == HAMMER_OFF_BAD)
 264                 return(NULL);
 265
 266         if (AssertOnFailure) {
 267                 assert((buf_offset & HAMMER_OFF_ZONE_MASK) ==
 268                        HAMMER_ZONE_RAW_BUFFER);
 269         }
 270         vol_no = HAMMER_VOL_DECODE(buf_offset);
 271         volume = get_volume(vol_no);
 272         if (volume == NULL)
 273                 return(NULL);
 274
 275         buf_offset &= ~HAMMER_BUFMASK64;
 276         buf = find_buffer(volume, buf_offset);
 277
 278         if (buf == NULL) {
 279                 buf = malloc(sizeof(*buf));
 280                 bzero(buf, sizeof(*buf));
 281                 if (DebugOpt > 1) {
 282                         fprintf(stderr, "get_buffer: %016llx %016llx at %p\n",
 283                                 (long long)orig_offset, (long long)buf_offset,
 284                                 buf);
 285                 }
 286                 buf->buf_offset = buf_offset;
 287                 buf->raw_offset = hammer_xlate_to_phys(volume->ondisk,
 288                                                         buf_offset);
 289                 buf->volume = volume;
 290                 hi = buffer_hash(buf_offset);
 291                 TAILQ_INSERT_TAIL(&volume->buffer_lists[hi], buf, entry);
 292                 ++volume->cache.refs;
 293                 buf->cache.u.buffer = buf;
 294                 hammer_cache_add(&buf->cache, ISBUFFER);
 295                 dora = (isnew == 0);
 296         } else {
 297                 if (DebugOpt > 1) {
 298                         fprintf(stderr, "get_buffer: %016llx %016llx at %p *\n",
 299                                 (long long)orig_offset, (long long)buf_offset,
 300                                 buf);
 301                 }
 302                 hammer_cache_used(&buf->cache);
 303                 ++buf->use_count;
 304         }
 305         ++buf->cache.refs;
 306         hammer_cache_flush();
 307         if ((ondisk = buf->ondisk) == NULL) {
 308                 buf->ondisk = ondisk = malloc(HAMMER_BUFSIZE);
 309                 if (isnew <= 0) {
 310                         n = readhammerbuf(volume, ondisk, buf->raw_offset);
 311                         if (n == -1) {
 312                                 if (AssertOnFailure)
 313                                         err(1, "get_buffer: %s:%016llx "
 314                                             "Read failed at offset %016llx",
 315                                             volume->name,
 316                                             (long long)buf->buf_offset,
 317                                             (long long)buf->raw_offset);
 318                                 bzero(ondisk, HAMMER_BUFSIZE);
 319                         }
 320                 }
 321         }
 322         if (isnew > 0) {
 323                 bzero(ondisk, HAMMER_BUFSIZE);
 324                 buf->cache.modified = 1;
 325         }
 326         if (dora)
 327                 get_buffer_readahead(buf);
 328         return(buf);
 329 }
 330
 331 static void
 332 get_buffer_readahead(struct buffer_info *base)
 333 {
 334         struct buffer_info *buf;
 335         struct volume_info *vol;
 336         hammer_off_t buf_offset;
 337         int64_t raw_offset;
 338         int ri = UseReadBehind;
 339         int re = UseReadAhead;
 340
 341         raw_offset = base->raw_offset + ri * HAMMER_BUFSIZE;
 342         vol = base->volume;
 343
 344         while (ri < re) {
 345                 if (raw_offset >= vol->ondisk->vol_buf_end)
 346                         break;
 347                 if (raw_offset < vol->ondisk->vol_buf_beg || ri == 0) {
 348                         ++ri;
 349                         raw_offset += HAMMER_BUFSIZE;
 350                         continue;
 351                 }
 352                 buf_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no,
 353                         raw_offset - vol->ondisk->vol_buf_beg);
 354                 buf = find_buffer(vol, buf_offset);
 355                 if (buf == NULL) {
 356                         buf = get_buffer(buf_offset, -1);
 357                         rel_buffer(buf);
 358                 }
 359                 ++ri;
 360                 raw_offset += HAMMER_BUFSIZE;
 361         }
 362 }
 363
 364 void
 365 rel_buffer(struct buffer_info *buffer)
 366 {
 367         struct volume_info *volume;
 368         int hi;
 369
 370         if (buffer == NULL)
 371                 return;
 372         assert(buffer->cache.refs > 0);
 373         if (--buffer->cache.refs == 0) {
 374                 if (buffer->cache.delete) {
 375                         hi = buffer_hash(buffer->buf_offset);
 376                         volume = buffer->volume;
 377                         if (buffer->cache.modified)
 378                                 flush_buffer(buffer);
 379                         TAILQ_REMOVE(&volume->buffer_lists[hi], buffer, entry);
 380                         hammer_cache_del(&buffer->cache);
 381                         free(buffer->ondisk);
 382                         free(buffer);
 383                         rel_volume(volume);
 384                 }
 385         }
 386 }
 387
 388 /*
 389  * Retrieve a pointer to a buffer data given a buffer offset.  The underlying
 390  * bufferp is freed if isnew or the offset is out of range of the cached data.
 391  * If bufferp is freed a referenced buffer is loaded into it.
 392  */
 393 void *
 394 get_buffer_data(hammer_off_t buf_offset, struct buffer_info **bufferp,
 395                 int isnew)
 396 {
 397         if (*bufferp != NULL) {
 398                 if (isnew > 0 ||
 399                     (((*bufferp)->buf_offset ^ buf_offset) & ~HAMMER_BUFMASK64)) {
 400                         rel_buffer(*bufferp);
 401                         *bufferp = NULL;
 402                 }
 403         }
 404         return(get_ondisk(buf_offset, bufferp, isnew));
 405 }
 406
 407 /*
 408  * Retrieve a pointer to a B-Tree node given a zone offset.  The underlying
 409  * bufferp is freed if non-NULL and a referenced buffer is loaded into it.
 410  */
 411 hammer_node_ondisk_t
 412 get_node(hammer_off_t node_offset, struct buffer_info **bufferp)
 413 {
 414         if (*bufferp != NULL) {
 415                 rel_buffer(*bufferp);
 416                 *bufferp = NULL;
 417         }
 418         return(get_ondisk(node_offset, bufferp, 0));
 419 }
 420
 421 /*
 422  * Return a pointer to a buffer data given a buffer offset.
 423  * If *bufferp is NULL acquire the buffer otherwise use that buffer.
 424  */
 425 static __inline
 426 void *
 427 get_ondisk(hammer_off_t buf_offset, struct buffer_info **bufferp, int isnew)
 428 {
 429         struct buffer_info *buffer;
 430
 431         buffer = *bufferp;
 432         if (buffer == NULL) {
 433                 buffer = *bufferp = get_buffer(buf_offset, isnew);
 434                 if (buffer == NULL)
 435                         return(NULL);
 436         }
 437
 438         return((char *)buffer->ondisk +
 439                 ((int32_t)buf_offset & HAMMER_BUFMASK));
 440 }
 441
 442 /*
 443  * Allocate HAMMER elements - btree nodes, meta data, data storage
 444  */
 445 void *
 446 alloc_btree_element(hammer_off_t *offp, struct buffer_info **data_bufferp)
 447 {
 448         hammer_node_ondisk_t node;
 449
 450         node = alloc_blockmap(HAMMER_ZONE_BTREE_INDEX, sizeof(*node),
 451                               offp, data_bufferp);
 452         bzero(node, sizeof(*node));
 453         return (node);
 454 }
 455
 456 void *
 457 alloc_meta_element(hammer_off_t *offp, int32_t data_len,
 458                    struct buffer_info **data_bufferp)
 459 {
 460         void *data;
 461
 462         data = alloc_blockmap(HAMMER_ZONE_META_INDEX, data_len,
 463                               offp, data_bufferp);
 464         bzero(data, data_len);
 465         return (data);
 466 }
 467
 468 /*
 469  * The only data_len supported by HAMMER userspace for large data zone
 470  * (zone 10) is HAMMER_BUFSIZE which is 16KB.  >16KB data does not fit
 471  * in a buffer allocated by get_buffer().  Also alloc_blockmap() does
 472  * not consider >16KB buffer size.
 473  */
 474 void *
 475 alloc_data_element(hammer_off_t *offp, int32_t data_len,
 476                    struct buffer_info **data_bufferp)
 477 {
 478         void *data;
 479         int zone;
 480
 481         if (data_len == 0)
 482                 return(NULL);
 483
 484         zone = hammer_data_zone_index(data_len);
 485         assert(data_len <= HAMMER_BUFSIZE); /* just one buffer */
 486         assert(zone == HAMMER_ZONE_LARGE_DATA_INDEX ||
 487                zone == HAMMER_ZONE_SMALL_DATA_INDEX);
 488
 489         data = alloc_blockmap(zone, data_len, offp, data_bufferp);
 490         bzero(data, data_len);
 491         return(data);
 492 }
 493
 494 /*
 495  * Format a new freemap.  Set all layer1 entries to UNAVAIL.  The initialize
 496  * code will load each volume's freemap.
 497  */
 498 void
 499 format_freemap(struct volume_info *root_vol)
 500 {
 501         struct buffer_info *buffer = NULL;
 502         hammer_off_t layer1_offset;
 503         hammer_blockmap_t blockmap;
 504         struct hammer_blockmap_layer1 *layer1;
 505         int i, isnew;
 506
 507         /* Only root volume needs formatting */
 508         assert(root_vol->vol_no == RootVolNo);
 509
 510         layer1_offset = alloc_bigblock(root_vol, HAMMER_ZONE_FREEMAP_INDEX);
 511         for (i = 0; i < HAMMER_BIGBLOCK_SIZE; i += sizeof(*layer1)) {
 512                 isnew = ((i % HAMMER_BUFSIZE) == 0);
 513                 layer1 = get_buffer_data(layer1_offset + i, &buffer, isnew);
 514                 bzero(layer1, sizeof(*layer1));
 515                 layer1->phys_offset = HAMMER_BLOCKMAP_UNAVAIL;
 516                 layer1->blocks_free = 0;
 517                 layer1->layer1_crc = crc32(layer1, HAMMER_LAYER1_CRCSIZE);
 518         }
 519         assert(i == HAMMER_BIGBLOCK_SIZE);
 520         rel_buffer(buffer);
 521
 522         blockmap = &root_vol->ondisk->vol0_blockmap[HAMMER_ZONE_FREEMAP_INDEX];
 523         bzero(blockmap, sizeof(*blockmap));
 524         blockmap->phys_offset = layer1_offset;
 525         blockmap->first_offset = 0;
 526         blockmap->next_offset = HAMMER_ENCODE_RAW_BUFFER(0, 0);
 527         blockmap->alloc_offset = HAMMER_ENCODE_RAW_BUFFER(255, -1);
 528         blockmap->entry_crc = crc32(blockmap, HAMMER_BLOCKMAP_CRCSIZE);
 529         root_vol->cache.modified = 1;
 530 }
 531
 532 /*
 533  * Load the volume's remaining free space into the freemap.
 534  *
 535  * Returns the number of big-blocks available.
 536  */
 537 int64_t
 538 initialize_freemap(struct volume_info *vol)
 539 {
 540         struct volume_info *root_vol;
 541         struct buffer_info *buffer1 = NULL;
 542         struct buffer_info *buffer2 = NULL;
 543         struct hammer_blockmap_layer1 *layer1;
 544         struct hammer_blockmap_layer2 *layer2;
 545         hammer_off_t layer1_base;
 546         hammer_off_t layer1_offset;
 547         hammer_off_t layer2_offset;
 548         hammer_off_t phys_offset;
 549         hammer_off_t block_offset;
 550         hammer_off_t aligned_vol_free_end;
 551         hammer_blockmap_t freemap;
 552         int64_t count = 0;
 553         int64_t layer1_count = 0;
 554
 555         root_vol = get_volume(RootVolNo);
 556         aligned_vol_free_end = (vol->vol_free_end + HAMMER_BLOCKMAP_LAYER2_MASK)
 557                                 & ~HAMMER_BLOCKMAP_LAYER2_MASK;
 558
 559         printf("initialize freemap volume %d\n", vol->vol_no);
 560
 561         /*
 562          * Initialize the freemap.  First preallocate the big-blocks required
 563          * to implement layer2.   This preallocation is a bootstrap allocation
 564          * using blocks from the target volume.
 565          */
 566         freemap = &root_vol->ondisk->vol0_blockmap[HAMMER_ZONE_FREEMAP_INDEX];
 567         layer1_base = freemap->phys_offset;
 568
 569         for (phys_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no, 0);
 570              phys_offset < aligned_vol_free_end;
 571              phys_offset += HAMMER_BLOCKMAP_LAYER2) {
 572                 layer1_offset = layer1_base +
 573                                 HAMMER_BLOCKMAP_LAYER1_OFFSET(phys_offset);
 574                 layer1 = get_buffer_data(layer1_offset, &buffer1, 0);
 575                 if (layer1->phys_offset == HAMMER_BLOCKMAP_UNAVAIL) {
 576                         layer1->phys_offset = alloc_bigblock(vol,
 577                                                 HAMMER_ZONE_FREEMAP_INDEX);
 578                         layer1->blocks_free = 0;
 579                         buffer1->cache.modified = 1;
 580                         layer1->layer1_crc = crc32(layer1,
 581                                                    HAMMER_LAYER1_CRCSIZE);
 582                 }
 583         }
 584
 585         /*
 586          * Now fill everything in.
 587          */
 588         for (phys_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no, 0);
 589              phys_offset < aligned_vol_free_end;
 590              phys_offset += HAMMER_BLOCKMAP_LAYER2) {
 591                 layer1_count = 0;
 592                 layer1_offset = layer1_base +
 593                                 HAMMER_BLOCKMAP_LAYER1_OFFSET(phys_offset);
 594                 layer1 = get_buffer_data(layer1_offset, &buffer1, 0);
 595                 assert(layer1->phys_offset != HAMMER_BLOCKMAP_UNAVAIL);
 596
 597                 for (block_offset = 0;
 598                      block_offset < HAMMER_BLOCKMAP_LAYER2;
 599                      block_offset += HAMMER_BIGBLOCK_SIZE) {
 600                         layer2_offset = layer1->phys_offset +
 601                                         HAMMER_BLOCKMAP_LAYER2_OFFSET(block_offset);
 602                         layer2 = get_buffer_data(layer2_offset, &buffer2, 0);
 603                         bzero(layer2, sizeof(*layer2));
 604
 605                         if (phys_offset + block_offset < vol->vol_free_off) {
 606                                 /*
 607                                  * Fixups XXX - big-blocks already allocated as part
 608                                  * of the freemap bootstrap.
 609                                  */
 610                                 if (layer2->zone == 0) {
 611                                         layer2->zone = HAMMER_ZONE_FREEMAP_INDEX;
 612                                         layer2->append_off = HAMMER_BIGBLOCK_SIZE;
 613                                         layer2->bytes_free = 0;
 614                                 }
 615                         } else if (phys_offset + block_offset < vol->vol_free_end) {
 616                                 layer2->zone = 0;
 617                                 layer2->append_off = 0;
 618                                 layer2->bytes_free = HAMMER_BIGBLOCK_SIZE;
 619                                 ++count;
 620                                 ++layer1_count;
 621                         } else {
 622                                 layer2->zone = HAMMER_ZONE_UNAVAIL_INDEX;
 623                                 layer2->append_off = HAMMER_BIGBLOCK_SIZE;
 624                                 layer2->bytes_free = 0;
 625                         }
 626                         layer2->entry_crc = crc32(layer2, HAMMER_LAYER2_CRCSIZE);
 627                         buffer2->cache.modified = 1;
 628                 }
 629
 630                 layer1->blocks_free += layer1_count;
 631                 layer1->layer1_crc = crc32(layer1, HAMMER_LAYER1_CRCSIZE);
 632                 buffer1->cache.modified = 1;
 633         }
 634
 635         rel_buffer(buffer1);
 636         rel_buffer(buffer2);
 637         rel_volume(root_vol);
 638         return(count);
 639 }
 640
 641 /*
 642  * Returns the number of big-blocks available for filesystem data and undos
 643  * without formatting.
 644  */
 645 int64_t
 646 count_freemap(struct volume_info *vol)
 647 {
 648         hammer_off_t phys_offset;
 649         hammer_off_t vol_free_off;
 650         hammer_off_t aligned_vol_free_end;
 651         int64_t count = 0;
 652
 653         vol_free_off = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no, 0);
 654         aligned_vol_free_end = (vol->vol_free_end + HAMMER_BLOCKMAP_LAYER2_MASK)
 655                                 & ~HAMMER_BLOCKMAP_LAYER2_MASK;
 656
 657         if (vol->vol_no == RootVolNo)
 658                 vol_free_off += HAMMER_BIGBLOCK_SIZE;
 659
 660         for (phys_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no, 0);
 661              phys_offset < aligned_vol_free_end;
 662              phys_offset += HAMMER_BLOCKMAP_LAYER2) {
 663                 vol_free_off += HAMMER_BIGBLOCK_SIZE;
 664         }
 665
 666         for (phys_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no, 0);
 667              phys_offset < aligned_vol_free_end;
 668              phys_offset += HAMMER_BIGBLOCK_SIZE) {
 669                 if (phys_offset < vol_free_off) {
 670                         ;
 671                 } else if (phys_offset < vol->vol_free_end) {
 672                         ++count;
 673                 }
 674         }
 675
 676         return(count);
 677 }
 678
 679 /*
 680  * Format the undomap for the root volume.
 681  */
 682 void
 683 format_undomap(struct volume_info *root_vol)
 684 {
 685         const int undo_zone = HAMMER_ZONE_UNDO_INDEX;
 686         hammer_off_t undo_limit;
 687         hammer_blockmap_t blockmap;
 688         struct hammer_volume_ondisk *ondisk;
 689         struct buffer_info *buffer = NULL;
 690         hammer_off_t scan;
 691         int n;
 692         int limit_index;
 693         uint32_t seqno;
 694
 695         /* Only root volume needs formatting */
 696         assert(root_vol->vol_no == RootVolNo);
 697         ondisk = root_vol->ondisk;
 698
 699         /*
 700          * Size the undo buffer in multiples of HAMMER_BIGBLOCK_SIZE,
 701          * up to HAMMER_UNDO_LAYER2 big-blocks.  Size to approximately
 702          * 0.1% of the disk.
 703          *
 704          * The minimum UNDO fifo size is 500MB, or approximately 1% of
 705          * the recommended 50G disk.
 706          *
 707          * Changing this minimum is rather dangerous as complex filesystem
 708          * operations can cause the UNDO FIFO to fill up otherwise.
 709          */
 710         undo_limit = UndoBufferSize;
 711         if (undo_limit == 0) {
 712                 undo_limit = (ondisk->vol_buf_end - ondisk->vol_buf_beg) / 1000;
 713                 if (undo_limit < 500*1024*1024)
 714                         undo_limit = 500*1024*1024;
 715         }
 716         undo_limit = (undo_limit + HAMMER_BIGBLOCK_MASK64) &
 717                      ~HAMMER_BIGBLOCK_MASK64;
 718         if (undo_limit < HAMMER_BIGBLOCK_SIZE)
 719                 undo_limit = HAMMER_BIGBLOCK_SIZE;
 720         if (undo_limit > HAMMER_BIGBLOCK_SIZE * HAMMER_UNDO_LAYER2)
 721                 undo_limit = HAMMER_BIGBLOCK_SIZE * HAMMER_UNDO_LAYER2;
 722         UndoBufferSize = undo_limit;
 723
 724         blockmap = &ondisk->vol0_blockmap[undo_zone];
 725         bzero(blockmap, sizeof(*blockmap));
 726         blockmap->phys_offset = HAMMER_BLOCKMAP_UNAVAIL;
 727         blockmap->first_offset = HAMMER_ZONE_ENCODE(undo_zone, 0);
 728         blockmap->next_offset = blockmap->first_offset;
 729         blockmap->alloc_offset = HAMMER_ZONE_ENCODE(undo_zone, undo_limit);
 730         blockmap->entry_crc = crc32(blockmap, HAMMER_BLOCKMAP_CRCSIZE);
 731
 732         limit_index = undo_limit / HAMMER_BIGBLOCK_SIZE;
 733         assert(limit_index <= HAMMER_UNDO_LAYER2);
 734
 735         for (n = 0; n < limit_index; ++n) {
 736                 ondisk->vol0_undo_array[n] = alloc_bigblock(NULL,
 737                                                         HAMMER_ZONE_UNDO_INDEX);
 738         }
 739         while (n < HAMMER_UNDO_LAYER2) {
 740                 ondisk->vol0_undo_array[n++] = HAMMER_BLOCKMAP_UNAVAIL;
 741         }
 742
 743         /*
 744          * Pre-initialize the UNDO blocks (HAMMER version 4+)
 745          */
 746         printf("initializing the undo map (%jd MB)\n",
 747                 (intmax_t)(blockmap->alloc_offset & HAMMER_OFF_LONG_MASK) /
 748                 (1024 * 1024));
 749
 750         scan = blockmap->first_offset;
 751         seqno = 0;
 752
 753         while (scan < blockmap->alloc_offset) {
 754                 hammer_fifo_head_t head;
 755                 hammer_fifo_tail_t tail;
 756                 int isnew;
 757                 int bytes = HAMMER_UNDO_ALIGN;
 758
 759                 isnew = ((scan & HAMMER_BUFMASK64) == 0);
 760                 head = get_buffer_data(scan, &buffer, isnew);
 761                 buffer->cache.modified = 1;
 762                 tail = (void *)((char *)head + bytes - sizeof(*tail));
 763
 764                 bzero(head, bytes);
 765                 head->hdr_signature = HAMMER_HEAD_SIGNATURE;
 766                 head->hdr_type = HAMMER_HEAD_TYPE_DUMMY;
 767                 head->hdr_size = bytes;
 768                 head->hdr_seq = seqno++;
 769
 770                 tail->tail_signature = HAMMER_TAIL_SIGNATURE;
 771                 tail->tail_type = HAMMER_HEAD_TYPE_DUMMY;
 772                 tail->tail_size = bytes;
 773
 774                 head->hdr_crc = crc32(head, HAMMER_FIFO_HEAD_CRCOFF) ^
 775                                 crc32(head + 1, bytes - sizeof(*head));
 776
 777                 scan += bytes;
 778         }
 779         rel_buffer(buffer);
 780 }
 781
 782 /*
 783  * Format a new blockmap.  This is mostly a degenerate case because
 784  * all allocations are now actually done from the freemap.
 785  */
 786 void
 787 format_blockmap(hammer_blockmap_t blockmap, int zone, hammer_off_t offset)
 788 {
 789         hammer_off_t zone_base = HAMMER_ZONE_ENCODE(zone, offset);
 790
 791         bzero(blockmap, sizeof(*blockmap));
 792         blockmap->phys_offset = 0;
 793         blockmap->first_offset = zone_base;
 794         blockmap->next_offset = zone_base;
 795         blockmap->alloc_offset = HAMMER_ENCODE(zone, 255, -1);
 796         blockmap->entry_crc = crc32(blockmap, HAMMER_BLOCKMAP_CRCSIZE);
 797 }
 798
 799 /*
 800  * Flush various tracking structures to disk
 801  */
 802 void
 803 flush_all_volumes(void)
 804 {
 805         struct volume_info *vol;
 806
 807         TAILQ_FOREACH(vol, &VolList, entry)
 808                 flush_volume(vol);
 809 }
 810
 811 void
 812 flush_volume(struct volume_info *volume)
 813 {
 814         struct buffer_info *buffer;
 815         int i;
 816
 817         for (i = 0; i < HAMMER_BUFLISTS; ++i) {
 818                 TAILQ_FOREACH(buffer, &volume->buffer_lists[i], entry)
 819                         flush_buffer(buffer);
 820         }
 821         if (writehammerbuf(volume, volume->ondisk, 0) == -1)
 822                 err(1, "Write volume %d (%s)", volume->vol_no, volume->name);
 823         volume->cache.modified = 0;
 824 }
 825
 826 void
 827 flush_buffer(struct buffer_info *buffer)
 828 {
 829         struct volume_info *vol;
 830
 831         vol = buffer->volume;
 832         if (writehammerbuf(vol, buffer->ondisk, buffer->raw_offset) == -1)
 833                 err(1, "Write volume %d (%s)", vol->vol_no, vol->name);
 834         buffer->cache.modified = 0;
 835 }
 836
 837 /*
 838  * Core I/O operations
 839  */
 840 static int
 841 readhammerbuf(struct volume_info *vol, void *data, int64_t offset)
 842 {
 843         ssize_t n;
 844
 845         n = pread(vol->fd, data, HAMMER_BUFSIZE, offset);
 846         if (n != HAMMER_BUFSIZE)
 847                 return(-1);
 848         return(0);
 849 }
 850
 851 static int
 852 writehammerbuf(struct volume_info *vol, const void *data, int64_t offset)
 853 {
 854         ssize_t n;
 855
 856         n = pwrite(vol->fd, data, HAMMER_BUFSIZE, offset);
 857         if (n != HAMMER_BUFSIZE)
 858                 return(-1);
 859         return(0);
 860 }
 861
 862 int64_t init_boot_area_size(int64_t value, off_t avg_vol_size)
 863 {
 864         if (value == 0) {
 865                 value = HAMMER_BOOT_NOMBYTES;
 866                 while (value > avg_vol_size / HAMMER_MAX_VOLUMES)
 867                         value >>= 1;
 868                 if (value < HAMMER_BOOT_MINBYTES)
 869                         value = 0;
 870         } else if (value < HAMMER_BOOT_MINBYTES) {
 871                 value = HAMMER_BOOT_MINBYTES;
 872         }
 873
 874         return(value);
 875 }
 876
 877 int64_t init_mem_area_size(int64_t value, off_t avg_vol_size)
 878 {
 879         if (value == 0) {
 880                 value = HAMMER_MEM_NOMBYTES;
 881                 while (value > avg_vol_size / HAMMER_MAX_VOLUMES)
 882                         value >>= 1;
 883                 if (value < HAMMER_MEM_MINBYTES)
 884                         value = 0;
 885         } else if (value < HAMMER_MEM_MINBYTES) {
 886                 value = HAMMER_MEM_MINBYTES;
 887         }
 888
 889         return(value);
 890 }