sys/vfs/hammer/hammer_volume.c

   1 /*
   2  * Copyright (c) 2009 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> and
   6  * Michael Neumann <mneumann@ntecs.de>
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  *
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in
  16  *    the documentation and/or other materials provided with the
  17  *    distribution.
  18  * 3. Neither the name of The DragonFly Project nor the names of its
  19  *    contributors may be used to endorse or promote products derived
  20  *    from this software without specific, prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  23  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  24  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  25  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  26  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  27  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  28  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  29  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  30  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  31  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  32  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  *
  35  */
  36
  37 #include "hammer.h"
  38 #include <sys/fcntl.h>
  39 #include <sys/nlookup.h>
  40 #include <sys/buf.h>
  41
  42 static int
  43 hammer_setup_device(struct vnode **devvpp, const char *dev_path, int ronly);
  44
  45 static void
  46 hammer_close_device(struct vnode **devvpp, int ronly);
  47
  48 static int
  49 hammer_format_volume_header(struct hammer_mount *hmp, struct vnode *devvp,
  50         const char *vol_name, int vol_no, int vol_count,
  51         int64_t vol_size, int64_t boot_area_size, int64_t mem_area_size);
  52
  53 static int
  54 hammer_clear_volume_header(struct vnode *devvp);
  55
  56 struct bigblock_stat {
  57         uint64_t total_bigblocks;
  58         uint64_t total_free_bigblocks;
  59         uint64_t counter;
  60 };
  61
  62 static int
  63 hammer_format_freemap(hammer_transaction_t trans, hammer_volume_t volume,
  64         struct bigblock_stat *stat);
  65
  66 static int
  67 hammer_free_freemap(hammer_transaction_t trans, hammer_volume_t volume,
  68         struct bigblock_stat *stat);
  69
  70 int
  71 hammer_ioc_volume_add(hammer_transaction_t trans, hammer_inode_t ip,
  72                 struct hammer_ioc_volume *ioc)
  73 {
  74         struct hammer_mount *hmp = trans->hmp;
  75         struct mount *mp = hmp->mp;
  76         hammer_volume_t volume;
  77         int error;
  78
  79         if (mp->mnt_flag & MNT_RDONLY) {
  80                 kprintf("Cannot add volume to read-only HAMMER filesystem\n");
  81                 return (EINVAL);
  82         }
  83
  84         if (hmp->nvolumes + 1 >= HAMMER_MAX_VOLUMES) {
  85                 kprintf("Max number of HAMMER volumes exceeded\n");
  86                 return (EINVAL);
  87         }
  88
  89         if (hammer_lock_ex_try(&hmp->volume_lock) != 0) {
  90                 kprintf("Another volume operation is in progress!\n");
  91                 return (EAGAIN);
  92         }
  93
  94         /*
  95          * Find an unused volume number.
  96          */
  97         int free_vol_no = 0;
  98         while (free_vol_no < HAMMER_MAX_VOLUMES &&
  99                RB_LOOKUP(hammer_vol_rb_tree, &hmp->rb_vols_root, free_vol_no)) {
 100                 ++free_vol_no;
 101         }
 102         if (free_vol_no >= HAMMER_MAX_VOLUMES) {
 103                 kprintf("Max number of HAMMER volumes exceeded\n");
 104                 hammer_unlock(&hmp->volume_lock);
 105                 return (EINVAL);
 106         }
 107
 108         struct vnode *devvp = NULL;
 109         error = hammer_setup_device(&devvp, ioc->device_name, 0);
 110         if (error)
 111                 goto end;
 112         KKASSERT(devvp);
 113         error = hammer_format_volume_header(
 114                 hmp,
 115                 devvp,
 116                 hmp->rootvol->ondisk->vol_name,
 117                 free_vol_no,
 118                 hmp->nvolumes+1,
 119                 ioc->vol_size,
 120                 ioc->boot_area_size,
 121                 ioc->mem_area_size);
 122         hammer_close_device(&devvp, 0);
 123         if (error)
 124                 goto end;
 125
 126         error = hammer_install_volume(hmp, ioc->device_name, NULL);
 127         if (error)
 128                 goto end;
 129
 130         hammer_sync_lock_sh(trans);
 131         hammer_lock_ex(&hmp->blkmap_lock);
 132
 133         ++hmp->nvolumes;
 134
 135         /*
 136          * Set each volumes new value of the vol_count field.
 137          */
 138         for (int vol_no = 0; vol_no < HAMMER_MAX_VOLUMES; ++vol_no) {
 139                 volume = hammer_get_volume(hmp, vol_no, &error);
 140                 if (volume == NULL && error == ENOENT) {
 141                         /*
 142                          * Skip unused volume numbers
 143                          */
 144                         error = 0;
 145                         continue;
 146                 }
 147                 KKASSERT(volume != NULL && error == 0);
 148                 hammer_modify_volume_field(trans, volume, vol_count);
 149                 volume->ondisk->vol_count = hmp->nvolumes;
 150                 hammer_modify_volume_done(volume);
 151
 152                 /*
 153                  * Only changes to the header of the root volume
 154                  * are automatically flushed to disk. For all
 155                  * other volumes that we modify we do it here.
 156                  */
 157                 if (volume != trans->rootvol && volume->io.modified) {
 158                         hammer_crc_set_volume(volume->ondisk);
 159                         hammer_io_flush(&volume->io, 0);
 160                 }
 161
 162                 hammer_rel_volume(volume, 0);
 163         }
 164
 165         volume = hammer_get_volume(hmp, free_vol_no, &error);
 166         KKASSERT(volume != NULL && error == 0);
 167
 168         struct bigblock_stat stat;
 169         error = hammer_format_freemap(trans, volume, &stat);
 170         KKASSERT(error == 0);
 171
 172         /*
 173          * Increase the total number of bigblocks
 174          */
 175         hammer_modify_volume_field(trans, trans->rootvol,
 176                 vol0_stat_bigblocks);
 177         trans->rootvol->ondisk->vol0_stat_bigblocks += stat.total_bigblocks;
 178         hammer_modify_volume_done(trans->rootvol);
 179
 180         /*
 181          * Increase the number of free bigblocks
 182          * (including the copy in hmp)
 183          */
 184         hammer_modify_volume_field(trans, trans->rootvol,
 185                 vol0_stat_freebigblocks);
 186         trans->rootvol->ondisk->vol0_stat_freebigblocks += stat.total_free_bigblocks;
 187         hmp->copy_stat_freebigblocks =
 188                 trans->rootvol->ondisk->vol0_stat_freebigblocks;
 189         hammer_modify_volume_done(trans->rootvol);
 190
 191         hammer_rel_volume(volume, 0);
 192
 193         hammer_unlock(&hmp->blkmap_lock);
 194         hammer_sync_unlock(trans);
 195
 196         KKASSERT(error == 0);
 197 end:
 198         hammer_unlock(&hmp->volume_lock);
 199         if (error)
 200                 kprintf("An error occurred: %d\n", error);
 201         return (error);
 202 }
 203
 204
 205 /*
 206  * Remove a volume.
 207  */
 208 int
 209 hammer_ioc_volume_del(hammer_transaction_t trans, hammer_inode_t ip,
 210                 struct hammer_ioc_volume *ioc)
 211 {
 212         struct hammer_mount *hmp = trans->hmp;
 213         struct mount *mp = hmp->mp;
 214         hammer_volume_t volume;
 215         int error = 0;
 216
 217         if (mp->mnt_flag & MNT_RDONLY) {
 218                 kprintf("Cannot del volume from read-only HAMMER filesystem\n");
 219                 return (EINVAL);
 220         }
 221
 222         if (hammer_lock_ex_try(&hmp->volume_lock) != 0) {
 223                 kprintf("Another volume operation is in progress!\n");
 224                 return (EAGAIN);
 225         }
 226
 227         volume = NULL;
 228
 229         /*
 230          * find volume by volname
 231          */
 232         for (int vol_no = 0; vol_no < HAMMER_MAX_VOLUMES; ++vol_no) {
 233                 volume = hammer_get_volume(hmp, vol_no, &error);
 234                 if (volume == NULL && error == ENOENT) {
 235                         /*
 236                          * Skip unused volume numbers
 237                          */
 238                         error = 0;
 239                         continue;
 240                 }
 241                 KKASSERT(volume != NULL && error == 0);
 242                 if (strcmp(volume->vol_name, ioc->device_name) == 0) {
 243                         break;
 244                 }
 245                 hammer_rel_volume(volume, 0);
 246                 volume = NULL;
 247         }
 248
 249         if (volume == NULL) {
 250                 kprintf("Couldn't find volume\n");
 251                 error = EINVAL;
 252                 goto end;
 253         }
 254
 255         if (volume == trans->rootvol) {
 256                 kprintf("Cannot remove root-volume\n");
 257                 hammer_rel_volume(volume, 0);
 258                 error = EINVAL;
 259                 goto end;
 260         }
 261
 262         /*
 263          *
 264          */
 265
 266         hmp->volume_to_remove = volume->vol_no;
 267
 268         struct hammer_ioc_reblock reblock;
 269         bzero(&reblock, sizeof(reblock));
 270
 271         reblock.key_beg.localization = HAMMER_MIN_LOCALIZATION;
 272         reblock.key_beg.obj_id = HAMMER_MIN_OBJID;
 273         reblock.key_end.localization = HAMMER_MAX_LOCALIZATION;
 274         reblock.key_end.obj_id = HAMMER_MAX_OBJID;
 275         reblock.head.flags = HAMMER_IOC_DO_FLAGS;
 276         reblock.free_level = 0;
 277
 278         error = hammer_ioc_reblock(trans, ip, &reblock);
 279
 280         if (reblock.head.flags & HAMMER_IOC_HEAD_INTR) {
 281                 error = EINTR;
 282         }
 283
 284         if (error) {
 285                 if (error == EINTR) {
 286                         kprintf("reblock was interrupted\n");
 287                 } else {
 288                         kprintf("reblock failed: %d\n", error);
 289                 }
 290                 hmp->volume_to_remove = -1;
 291                 hammer_rel_volume(volume, 0);
 292                 goto end;
 293         }
 294
 295         /*
 296          * Sync filesystem
 297          */
 298         int count = 0;
 299         while (hammer_flusher_haswork(hmp)) {
 300                 hammer_flusher_sync(hmp);
 301                 ++count;
 302                 if (count >= 5) {
 303                         if (count == 5)
 304                                 kprintf("HAMMER: flushing.");
 305                         else
 306                                 kprintf(".");
 307                         tsleep(&count, 0, "hmrufl", hz);
 308                 }
 309                 if (count == 30) {
 310                         kprintf("giving up");
 311                         break;
 312                 }
 313         }
 314         kprintf("\n");
 315
 316         hammer_sync_lock_sh(trans);
 317         hammer_lock_ex(&hmp->blkmap_lock);
 318
 319         /*
 320          * We use stat later to update rootvol's bigblock stats
 321          */
 322         struct bigblock_stat stat;
 323         error = hammer_free_freemap(trans, volume, &stat);
 324         if (error) {
 325                 kprintf("Failed to free volume. Volume not empty!\n");
 326                 hmp->volume_to_remove = -1;
 327                 hammer_rel_volume(volume, 0);
 328                 hammer_unlock(&hmp->blkmap_lock);
 329                 hammer_sync_unlock(trans);
 330                 goto end;
 331         }
 332
 333         hmp->volume_to_remove = -1;
 334
 335         hammer_rel_volume(volume, 0);
 336
 337         /*
 338          * Unload buffers
 339          */
 340         RB_SCAN(hammer_buf_rb_tree, &hmp->rb_bufs_root, NULL,
 341                 hammer_unload_buffer, volume);
 342
 343         error = hammer_unload_volume(volume, NULL);
 344         if (error == -1) {
 345                 kprintf("Failed to unload volume\n");
 346                 hammer_unlock(&hmp->blkmap_lock);
 347                 hammer_sync_unlock(trans);
 348                 goto end;
 349         }
 350
 351         volume = NULL;
 352         --hmp->nvolumes;
 353
 354         /*
 355          * Set each volume's new value of the vol_count field.
 356          */
 357         for (int vol_no = 0; vol_no < HAMMER_MAX_VOLUMES; ++vol_no) {
 358                 volume = hammer_get_volume(hmp, vol_no, &error);
 359                 if (volume == NULL && error == ENOENT) {
 360                         /*
 361                          * Skip unused volume numbers
 362                          */
 363                         error = 0;
 364                         continue;
 365                 }
 366
 367                 KKASSERT(volume != NULL && error == 0);
 368                 hammer_modify_volume_field(trans, volume, vol_count);
 369                 volume->ondisk->vol_count = hmp->nvolumes;
 370                 hammer_modify_volume_done(volume);
 371
 372                 /*
 373                  * Only changes to the header of the root volume
 374                  * are automatically flushed to disk. For all
 375                  * other volumes that we modify we do it here.
 376                  */
 377                 if (volume != trans->rootvol && volume->io.modified) {
 378                         hammer_crc_set_volume(volume->ondisk);
 379                         hammer_io_flush(&volume->io, 0);
 380                 }
 381
 382                 hammer_rel_volume(volume, 0);
 383         }
 384
 385         /*
 386          * Update the total number of bigblocks
 387          */
 388         hammer_modify_volume_field(trans, trans->rootvol,
 389                 vol0_stat_bigblocks);
 390         trans->rootvol->ondisk->vol0_stat_bigblocks -= stat.total_bigblocks;
 391         hammer_modify_volume_done(trans->rootvol);
 392
 393         /*
 394          * Update the number of free bigblocks
 395          * (including the copy in hmp)
 396          */
 397         hammer_modify_volume_field(trans, trans->rootvol,
 398                 vol0_stat_freebigblocks);
 399         trans->rootvol->ondisk->vol0_stat_freebigblocks -= stat.total_free_bigblocks;
 400         hmp->copy_stat_freebigblocks =
 401                 trans->rootvol->ondisk->vol0_stat_freebigblocks;
 402         hammer_modify_volume_done(trans->rootvol);
 403
 404
 405         hammer_unlock(&hmp->blkmap_lock);
 406         hammer_sync_unlock(trans);
 407
 408         /*
 409          * Erase the volume header of the removed device.
 410          *
 411          * This is to not accidentally mount the volume again.
 412          */
 413         struct vnode *devvp = NULL;
 414         error = hammer_setup_device(&devvp, ioc->device_name, 0);
 415         if (error) {
 416                 kprintf("Failed to open device: %s\n", ioc->device_name);
 417                 goto end;
 418         }
 419         KKASSERT(devvp);
 420         error = hammer_clear_volume_header(devvp);
 421         if (error) {
 422                 kprintf("Failed to clear volume header of device: %s\n",
 423                         ioc->device_name);
 424                 goto end;
 425         }
 426         hammer_close_device(&devvp, 0);
 427
 428         KKASSERT(error == 0);
 429 end:
 430         hammer_unlock(&hmp->volume_lock);
 431         return (error);
 432 }
 433
 434
 435 /*
 436  * Iterate over all usable L1 entries of the volume and
 437  * the corresponding L2 entries.
 438  */
 439 static int
 440 hammer_iterate_l1l2_entries(hammer_transaction_t trans, hammer_volume_t volume,
 441         int (*callback)(hammer_transaction_t, hammer_volume_t, hammer_buffer_t*,
 442                 struct hammer_blockmap_layer1*, struct hammer_blockmap_layer2*,
 443                 hammer_off_t, hammer_off_t, void*),
 444         void *data)
 445 {
 446         struct hammer_mount *hmp = trans->hmp;
 447         hammer_blockmap_t freemap = &hmp->blockmap[HAMMER_ZONE_FREEMAP_INDEX];
 448         hammer_buffer_t buffer = NULL;
 449         int error = 0;
 450
 451         hammer_off_t phys_off;
 452         hammer_off_t block_off;
 453         hammer_off_t layer1_off;
 454         hammer_off_t layer2_off;
 455         hammer_off_t aligned_buf_end_off;
 456         struct hammer_blockmap_layer1 *layer1;
 457         struct hammer_blockmap_layer2 *layer2;
 458
 459         /*
 460          * Calculate the usable size of the volume, which
 461          * must be aligned at a bigblock (8 MB) boundary.
 462          */
 463         aligned_buf_end_off = (HAMMER_ENCODE_RAW_BUFFER(volume->ondisk->vol_no,
 464                 (volume->ondisk->vol_buf_end - volume->ondisk->vol_buf_beg)
 465                 & ~HAMMER_LARGEBLOCK_MASK64));
 466
 467         /*
 468          * Iterate the volume's address space in chunks of 4 TB, where each
 469          * chunk consists of at least one physically available 8 MB bigblock.
 470          *
 471          * For each chunk we need one L1 entry and one L2 bigblock.
 472          * We use the first bigblock of each chunk as L2 block.
 473          */
 474         for (phys_off = HAMMER_ENCODE_RAW_BUFFER(volume->ondisk->vol_no, 0);
 475              phys_off < aligned_buf_end_off;
 476              phys_off += HAMMER_BLOCKMAP_LAYER2) {
 477                 for (block_off = 0;
 478                      block_off < HAMMER_BLOCKMAP_LAYER2;
 479                      block_off += HAMMER_LARGEBLOCK_SIZE) {
 480                         layer2_off = phys_off +
 481                                 HAMMER_BLOCKMAP_LAYER2_OFFSET(block_off);
 482                         layer2 = hammer_bread(hmp, layer2_off, &error, &buffer);
 483                         if (error)
 484                                 goto end;
 485
 486                         error = callback(trans, volume, &buffer, NULL,
 487                                          layer2, phys_off, block_off, data);
 488                         if (error)
 489                                 goto end;
 490                 }
 491
 492                 layer1_off = freemap->phys_offset +
 493                                 HAMMER_BLOCKMAP_LAYER1_OFFSET(phys_off);
 494                 layer1 = hammer_bread(hmp, layer1_off, &error, &buffer);
 495                 if (error)
 496                         goto end;
 497
 498                 error = callback(trans, volume, &buffer, layer1, NULL,
 499                                  phys_off, 0, data);
 500                 if (error)
 501                         goto end;
 502         }
 503
 504 end:
 505         if (buffer) {
 506                 hammer_rel_buffer(buffer, 0);
 507                 buffer = NULL;
 508         }
 509
 510         return error;
 511 }
 512
 513
 514 static int
 515 format_callback(hammer_transaction_t trans, hammer_volume_t volume,
 516         hammer_buffer_t *bufferp,
 517         struct hammer_blockmap_layer1 *layer1,
 518         struct hammer_blockmap_layer2 *layer2,
 519         hammer_off_t phys_off,
 520         hammer_off_t block_off,
 521         void *data)
 522 {
 523         struct bigblock_stat *stat = (struct bigblock_stat*)data;
 524
 525         /*
 526          * Calculate the usable size of the volume, which must be aligned
 527          * at a bigblock (8 MB) boundary.
 528          */
 529         hammer_off_t aligned_buf_end_off;
 530         aligned_buf_end_off = (HAMMER_ENCODE_RAW_BUFFER(volume->ondisk->vol_no,
 531                 (volume->ondisk->vol_buf_end - volume->ondisk->vol_buf_beg)
 532                 & ~HAMMER_LARGEBLOCK_MASK64));
 533
 534         if (layer1) {
 535                 KKASSERT(layer1->phys_offset == HAMMER_BLOCKMAP_UNAVAIL);
 536
 537                 hammer_modify_buffer(trans, *bufferp, layer1, sizeof(*layer1));
 538                 bzero(layer1, sizeof(layer1));
 539                 layer1->phys_offset = phys_off;
 540                 layer1->blocks_free = stat->counter;
 541                 layer1->layer1_crc = crc32(layer1, HAMMER_LAYER1_CRCSIZE);
 542                 hammer_modify_buffer_done(*bufferp);
 543
 544                 stat->total_free_bigblocks += stat->counter;
 545                 stat->counter = 0; /* reset */
 546         } else if (layer2) {
 547                 hammer_modify_buffer(trans, *bufferp, layer2, sizeof(*layer2));
 548                 bzero(layer2, sizeof(*layer2));
 549
 550                 if (block_off == 0) {
 551                         /*
 552                          * The first entry represents the L2 bigblock itself.
 553                          */
 554                         layer2->zone = HAMMER_ZONE_FREEMAP_INDEX;
 555                         layer2->append_off = HAMMER_LARGEBLOCK_SIZE;
 556                         layer2->bytes_free = 0;
 557                         ++stat->total_bigblocks;
 558                 } else if (phys_off + block_off < aligned_buf_end_off) {
 559                         /*
 560                          * Available bigblock
 561                          */
 562                         layer2->zone = 0;
 563                         layer2->append_off = 0;
 564                         layer2->bytes_free = HAMMER_LARGEBLOCK_SIZE;
 565                         ++stat->total_bigblocks;
 566                         ++stat->counter;
 567                 } else {
 568                         /*
 569                          * Bigblock outside of physically available
 570                          * space
 571                          */
 572                         layer2->zone = HAMMER_ZONE_UNAVAIL_INDEX;
 573                         layer2->append_off = HAMMER_LARGEBLOCK_SIZE;
 574                         layer2->bytes_free = 0;
 575                 }
 576
 577                 layer2->entry_crc = crc32(layer2, HAMMER_LAYER2_CRCSIZE);
 578                 hammer_modify_buffer_done(*bufferp);
 579         } else {
 580                 KKASSERT(0);
 581         }
 582
 583         return 0;
 584 }
 585
 586 static int
 587 hammer_format_freemap(hammer_transaction_t trans, hammer_volume_t volume,
 588         struct bigblock_stat *stat)
 589 {
 590         stat->total_bigblocks = 0;
 591         stat->total_free_bigblocks = 0;
 592         stat->counter = 0;
 593         return hammer_iterate_l1l2_entries(trans, volume, format_callback, stat);
 594 }
 595
 596 static int
 597 free_callback(hammer_transaction_t trans, hammer_volume_t volume __unused,
 598         hammer_buffer_t *bufferp,
 599         struct hammer_blockmap_layer1 *layer1,
 600         struct hammer_blockmap_layer2 *layer2,
 601         hammer_off_t phys_off,
 602         hammer_off_t block_off __unused,
 603         void *data)
 604 {
 605         struct bigblock_stat *stat = (struct bigblock_stat*)data;
 606
 607         /*
 608          * No modifications to ondisk structures
 609          */
 610         int testonly = (stat == NULL);
 611
 612         if (layer1) {
 613                 if (layer1->phys_offset == HAMMER_BLOCKMAP_UNAVAIL) {
 614                         /*
 615                          * This layer1 entry is already free.
 616                          */
 617                         return 0;
 618                 }
 619
 620                 KKASSERT((int)HAMMER_VOL_DECODE(layer1->phys_offset) ==
 621                         trans->hmp->volume_to_remove);
 622
 623                 if (testonly)
 624                         return 0;
 625
 626                 /*
 627                  * Free the L1 entry
 628                  */
 629                 hammer_modify_buffer(trans, *bufferp, layer1, sizeof(*layer1));
 630                 bzero(layer1, sizeof(layer1));
 631                 layer1->phys_offset = HAMMER_BLOCKMAP_UNAVAIL;
 632                 layer1->layer1_crc = crc32(layer1, HAMMER_LAYER1_CRCSIZE);
 633                 hammer_modify_buffer_done(*bufferp);
 634
 635                 return 0;
 636         } else if (layer2) {
 637                 if (layer2->zone == HAMMER_ZONE_UNAVAIL_INDEX) {
 638                         return 0;
 639                 }
 640
 641                 if (layer2->zone == HAMMER_ZONE_FREEMAP_INDEX) {
 642                         if (stat) {
 643                                 ++stat->total_bigblocks;
 644                         }
 645                         return 0;
 646                 }
 647
 648                 if (layer2->append_off == 0 &&
 649                     layer2->bytes_free == HAMMER_LARGEBLOCK_SIZE) {
 650                         if (stat) {
 651                                 ++stat->total_bigblocks;
 652                                 ++stat->total_free_bigblocks;
 653                         }
 654                         return 0;
 655                 }
 656
 657                 /*
 658                  * We found a layer2 entry that is not empty!
 659                  */
 660                 return EBUSY;
 661         } else {
 662                 KKASSERT(0);
 663         }
 664
 665         return EINVAL;
 666 }
 667
 668 static int
 669 hammer_free_freemap(hammer_transaction_t trans, hammer_volume_t volume,
 670         struct bigblock_stat *stat)
 671 {
 672         int error;
 673
 674         stat->total_bigblocks = 0;
 675         stat->total_free_bigblocks = 0;
 676         stat->counter = 0;
 677
 678         error = hammer_iterate_l1l2_entries(trans, volume, free_callback, NULL);
 679         if (error)
 680                 return error;
 681
 682         error = hammer_iterate_l1l2_entries(trans, volume, free_callback, stat);
 683         return error;
 684 }
 685
 686 /************************************************************************
 687  *                              MISC                                    *
 688  ************************************************************************
 689  */
 690
 691 static int
 692 hammer_setup_device(struct vnode **devvpp, const char *dev_path, int ronly)
 693 {
 694         int error;
 695         struct nlookupdata nd;
 696
 697         /*
 698          * Get the device vnode
 699          */
 700         if (*devvpp == NULL) {
 701                 error = nlookup_init(&nd, dev_path, UIO_SYSSPACE, NLC_FOLLOW);
 702                 if (error == 0)
 703                         error = nlookup(&nd);
 704                 if (error == 0)
 705                         error = cache_vref(&nd.nl_nch, nd.nl_cred, devvpp);
 706                 nlookup_done(&nd);
 707         } else {
 708                 error = 0;
 709         }
 710
 711         if (error == 0) {
 712                 if (vn_isdisk(*devvpp, &error)) {
 713                         error = vfs_mountedon(*devvpp);
 714                 }
 715         }
 716         if (error == 0 && vcount(*devvpp) > 0)
 717                 error = EBUSY;
 718         if (error == 0) {
 719                 vn_lock(*devvpp, LK_EXCLUSIVE | LK_RETRY);
 720                 error = vinvalbuf(*devvpp, V_SAVE, 0, 0);
 721                 if (error == 0) {
 722                         error = VOP_OPEN(*devvpp,
 723                                          (ronly ? FREAD : FREAD|FWRITE),
 724                                          FSCRED, NULL);
 725                 }
 726                 vn_unlock(*devvpp);
 727         }
 728         if (error && *devvpp) {
 729                 vrele(*devvpp);
 730                 *devvpp = NULL;
 731         }
 732         return (error);
 733 }
 734
 735 static void
 736 hammer_close_device(struct vnode **devvpp, int ronly)
 737 {
 738         VOP_CLOSE(*devvpp, (ronly ? FREAD : FREAD|FWRITE));
 739         if (*devvpp) {
 740                 vinvalbuf(*devvpp, ronly ? 0 : V_SAVE, 0, 0);
 741                 vrele(*devvpp);
 742                 *devvpp = NULL;
 743         }
 744 }
 745
 746 static int
 747 hammer_format_volume_header(struct hammer_mount *hmp, struct vnode *devvp,
 748         const char *vol_name, int vol_no, int vol_count,
 749         int64_t vol_size, int64_t boot_area_size, int64_t mem_area_size)
 750 {
 751         struct buf *bp = NULL;
 752         struct hammer_volume_ondisk *ondisk;
 753         int error;
 754
 755         /*
 756          * Extract the volume number from the volume header and do various
 757          * sanity checks.
 758          */
 759         KKASSERT(HAMMER_BUFSIZE >= sizeof(struct hammer_volume_ondisk));
 760         error = bread(devvp, 0LL, HAMMER_BUFSIZE, &bp);
 761         if (error || bp->b_bcount < sizeof(struct hammer_volume_ondisk))
 762                 goto late_failure;
 763
 764         ondisk = (struct hammer_volume_ondisk*) bp->b_data;
 765
 766         /*
 767          * Note that we do NOT allow to use a device that contains
 768          * a valid HAMMER signature. It has to be cleaned up with dd
 769          * before.
 770          */
 771         if (ondisk->vol_signature == HAMMER_FSBUF_VOLUME) {
 772                 kprintf("hammer_volume_add: Formatting of valid HAMMER volume "
 773                         "%s denied. Erase with dd!\n", vol_name);
 774                 error = EFTYPE;
 775                 goto late_failure;
 776         }
 777
 778         bzero(ondisk, sizeof(struct hammer_volume_ondisk));
 779         ksnprintf(ondisk->vol_name, sizeof(ondisk->vol_name), "%s", vol_name);
 780         ondisk->vol_fstype = hmp->rootvol->ondisk->vol_fstype;
 781         ondisk->vol_signature = HAMMER_FSBUF_VOLUME;
 782         ondisk->vol_fsid = hmp->fsid;
 783         ondisk->vol_rootvol = hmp->rootvol->vol_no;
 784         ondisk->vol_no = vol_no;
 785         ondisk->vol_count = vol_count;
 786         ondisk->vol_version = hmp->version;
 787
 788         /*
 789          * Reserve space for (future) header junk, setup our poor-man's
 790          * bigblock allocator.
 791          */
 792         int64_t vol_alloc = HAMMER_BUFSIZE * 16;
 793
 794         ondisk->vol_bot_beg = vol_alloc;
 795         vol_alloc += boot_area_size;
 796         ondisk->vol_mem_beg = vol_alloc;
 797         vol_alloc += mem_area_size;
 798
 799         /*
 800          * The remaining area is the zone 2 buffer allocation area.  These
 801          * buffers
 802          */
 803         ondisk->vol_buf_beg = vol_alloc;
 804         ondisk->vol_buf_end = vol_size & ~(int64_t)HAMMER_BUFMASK;
 805
 806         if (ondisk->vol_buf_end < ondisk->vol_buf_beg) {
 807                 kprintf("volume %d %s is too small to hold the volume header",
 808                      ondisk->vol_no, ondisk->vol_name);
 809                 error = EFTYPE;
 810                 goto late_failure;
 811         }
 812
 813         ondisk->vol_nblocks = (ondisk->vol_buf_end - ondisk->vol_buf_beg) /
 814                               HAMMER_BUFSIZE;
 815         ondisk->vol_blocksize = HAMMER_BUFSIZE;
 816
 817         /*
 818          * Write volume header to disk
 819          */
 820         error = bwrite(bp);
 821         bp = NULL;
 822
 823 late_failure:
 824         if (bp)
 825                 brelse(bp);
 826         return (error);
 827 }
 828
 829 /*
 830  * Invalidates the volume header. Used by volume-del.
 831  */
 832 static int
 833 hammer_clear_volume_header(struct vnode *devvp)
 834 {
 835         struct buf *bp = NULL;
 836         struct hammer_volume_ondisk *ondisk;
 837         int error;
 838
 839         KKASSERT(HAMMER_BUFSIZE >= sizeof(struct hammer_volume_ondisk));
 840         error = bread(devvp, 0LL, HAMMER_BUFSIZE, &bp);
 841         if (error || bp->b_bcount < sizeof(struct hammer_volume_ondisk))
 842                 goto late_failure;
 843
 844         ondisk = (struct hammer_volume_ondisk*) bp->b_data;
 845         bzero(ondisk, sizeof(struct hammer_volume_ondisk));
 846
 847         error = bwrite(bp);
 848         bp = NULL;
 849
 850 late_failure:
 851         if (bp)
 852                 brelse(bp);
 853         return (error);
 854 }