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 uint64_t
  54 hammer_format_freemap(hammer_transaction_t trans, hammer_volume_t volume);
  55
  56 static int
  57 hammer_free_freemap(hammer_transaction_t trans, hammer_volume_t volume);
  58
  59
  60 int
  61 hammer_ioc_volume_add(hammer_transaction_t trans, hammer_inode_t ip,
  62                 struct hammer_ioc_volume *ioc)
  63 {
  64         struct hammer_mount *hmp = trans->hmp;
  65         struct mount *mp = hmp->mp;
  66         hammer_volume_t volume;
  67         int error;
  68
  69         if (mp->mnt_flag & MNT_RDONLY) {
  70                 kprintf("Cannot add volume to read-only HAMMER filesystem\n");
  71                 return (EINVAL);
  72         }
  73
  74         if (hmp->nvolumes + 1 >= HAMMER_MAX_VOLUMES) {
  75                 kprintf("Max number of HAMMER volumes exceeded\n");
  76                 return (EINVAL);
  77         }
  78
  79         /*
  80          * Find an unused volume number.
  81          */
  82         int free_vol_no = 0;
  83         while (free_vol_no < HAMMER_MAX_VOLUMES &&
  84                RB_LOOKUP(hammer_vol_rb_tree, &hmp->rb_vols_root, free_vol_no)) {
  85                 ++free_vol_no;
  86         }
  87         if (free_vol_no >= HAMMER_MAX_VOLUMES) {
  88                 kprintf("Max number of HAMMER volumes exceeded\n");
  89                 return (EINVAL);
  90         }
  91
  92         struct vnode *devvp = NULL;
  93         error = hammer_setup_device(&devvp, ioc->device_name, 0);
  94         if (error)
  95                 goto end;
  96         KKASSERT(devvp);
  97         error = hammer_format_volume_header(
  98                 hmp,
  99                 devvp,
 100                 hmp->rootvol->ondisk->vol_name,
 101                 free_vol_no,
 102                 hmp->nvolumes+1,
 103                 ioc->vol_size,
 104                 ioc->boot_area_size,
 105                 ioc->mem_area_size);
 106         hammer_close_device(&devvp, 0);
 107         if (error)
 108                 goto end;
 109
 110         error = hammer_install_volume(hmp, ioc->device_name, NULL);
 111         if (error)
 112                 goto end;
 113
 114         hammer_sync_lock_sh(trans);
 115         hammer_lock_ex(&hmp->blkmap_lock);
 116
 117         ++hmp->nvolumes;
 118
 119         /*
 120          * Set each volumes new value of the vol_count field.
 121          */
 122         for (int vol_no = 0; vol_no < HAMMER_MAX_VOLUMES; ++vol_no) {
 123                 volume = hammer_get_volume(hmp, vol_no, &error);
 124                 if (volume == NULL && error == ENOENT) {
 125                         /*
 126                          * Skip unused volume numbers
 127                          */
 128                         error = 0;
 129                         continue;
 130                 }
 131                 KKASSERT(volume != NULL && error == 0);
 132                 hammer_modify_volume_field(trans, volume, vol_count);
 133                 volume->ondisk->vol_count = hmp->nvolumes;
 134                 hammer_modify_volume_done(volume);
 135
 136                 /*
 137                  * Only changes to the header of the root volume
 138                  * are automatically flushed to disk. For all
 139                  * other volumes that we modify we do it here.
 140                  */
 141                 if (volume != trans->rootvol && volume->io.modified) {
 142                         hammer_crc_set_volume(volume->ondisk);
 143                         hammer_io_flush(&volume->io, 0);
 144                 }
 145
 146                 hammer_rel_volume(volume, 0);
 147         }
 148
 149         volume = hammer_get_volume(hmp, free_vol_no, &error);
 150         KKASSERT(volume != NULL && error == 0);
 151
 152         uint64_t total_free_bigblocks =
 153                 hammer_format_freemap(trans, volume);
 154
 155         /*
 156          * Increase the total number of bigblocks
 157          */
 158         hammer_modify_volume_field(trans, trans->rootvol,
 159                 vol0_stat_bigblocks);
 160         trans->rootvol->ondisk->vol0_stat_bigblocks += total_free_bigblocks;
 161         hammer_modify_volume_done(trans->rootvol);
 162
 163         /*
 164          * Increase the number of free bigblocks
 165          * (including the copy in hmp)
 166          */
 167         hammer_modify_volume_field(trans, trans->rootvol,
 168                 vol0_stat_freebigblocks);
 169         trans->rootvol->ondisk->vol0_stat_freebigblocks += total_free_bigblocks;
 170         hmp->copy_stat_freebigblocks =
 171                 trans->rootvol->ondisk->vol0_stat_freebigblocks;
 172         hammer_modify_volume_done(trans->rootvol);
 173
 174         hammer_rel_volume(volume, 0);
 175
 176         hammer_unlock(&hmp->blkmap_lock);
 177         hammer_sync_unlock(trans);
 178
 179 end:
 180         if (error)
 181                 kprintf("An error occurred: %d\n", error);
 182         return (error);
 183 }
 184
 185
 186 /*
 187  * Remove a volume.
 188  */
 189 int
 190 hammer_ioc_volume_del(hammer_transaction_t trans, hammer_inode_t ip,
 191                 struct hammer_ioc_volume *ioc)
 192 {
 193         struct hammer_mount *hmp = trans->hmp;
 194         struct mount *mp = hmp->mp;
 195         hammer_volume_t volume;
 196         int error = 0;
 197
 198         if (mp->mnt_flag & MNT_RDONLY) {
 199                 kprintf("Cannot del volume from read-only HAMMER filesystem\n");
 200                 return (EINVAL);
 201         }
 202
 203
 204         volume = NULL;
 205
 206         /*
 207          * find volume by volname
 208          */
 209         for (int vol_no = 0; vol_no < HAMMER_MAX_VOLUMES; ++vol_no) {
 210                 volume = hammer_get_volume(hmp, vol_no, &error);
 211                 if (volume == NULL && error == ENOENT) {
 212                         /*
 213                          * Skip unused volume numbers
 214                          */
 215                         error = 0;
 216                         continue;
 217                 }
 218                 KKASSERT(volume != NULL && error == 0);
 219                 if (strcmp(volume->vol_name, ioc->device_name) == 0) {
 220                         break;
 221                 }
 222                 hammer_rel_volume(volume, 0);
 223                 volume = NULL;
 224         }
 225
 226         if (volume == NULL) {
 227                 kprintf("Couldn't find volume\n");
 228                 return (EINVAL);
 229         }
 230
 231         if (volume == trans->rootvol) {
 232                 kprintf("Cannot remove root-volume\n");
 233                 hammer_rel_volume(volume, 0);
 234                 return (EINVAL);
 235         }
 236
 237         /*
 238          *
 239          */
 240
 241         hmp->volume_to_remove = volume->vol_no;
 242
 243         struct hammer_ioc_reblock reblock;
 244         bzero(&reblock, sizeof(reblock));
 245
 246         reblock.key_beg.localization = HAMMER_MIN_LOCALIZATION;
 247         reblock.key_beg.obj_id = HAMMER_MIN_OBJID;
 248         reblock.key_end.localization = HAMMER_MAX_LOCALIZATION;
 249         reblock.key_end.obj_id = HAMMER_MAX_OBJID;
 250         reblock.head.flags = HAMMER_IOC_DO_FLAGS;
 251         reblock.free_level = 0;
 252
 253         error = hammer_ioc_reblock(trans, ip, &reblock);
 254
 255         if (reblock.head.flags & HAMMER_IOC_HEAD_INTR) {
 256                 error = EINTR;
 257         }
 258
 259         if (error) {
 260                 if (error == EINTR) {
 261                         kprintf("reblock was interrupted\n");
 262                 } else {
 263                         kprintf("reblock failed: %d\n", error);
 264                 }
 265                 hmp->volume_to_remove = -1;
 266                 hammer_rel_volume(volume, 0);
 267                 return (error);
 268         }
 269
 270         /*
 271          * Sync filesystem
 272          */
 273         int count = 0;
 274         while (hammer_flusher_haswork(hmp)) {
 275                 hammer_flusher_sync(hmp);
 276                 ++count;
 277                 if (count >= 5) {
 278                         if (count == 5)
 279                                 kprintf("HAMMER: flushing.");
 280                         else
 281                                 kprintf(".");
 282                         tsleep(&count, 0, "hmrufl", hz);
 283                 }
 284                 if (count == 30) {
 285                         kprintf("giving up");
 286                         break;
 287                 }
 288         }
 289         kprintf("\n");
 290
 291         hammer_sync_lock_sh(trans);
 292         hammer_lock_ex(&hmp->blkmap_lock);
 293
 294         error = hammer_free_freemap(trans, volume);
 295         if (error) {
 296                 kprintf("Failed to free volume\n");
 297                 hmp->volume_to_remove = -1;
 298                 hammer_rel_volume(volume, 0);
 299                 hammer_unlock(&hmp->blkmap_lock);
 300                 hammer_sync_unlock(trans);
 301                 return (error);
 302         }
 303
 304         hmp->volume_to_remove = -1;
 305
 306         hammer_rel_volume(volume, 0);
 307
 308         /*
 309          * Unload buffers
 310          */
 311         RB_SCAN(hammer_buf_rb_tree, &hmp->rb_bufs_root, NULL,
 312                 hammer_unload_buffer, volume);
 313
 314         error = hammer_unload_volume(volume, NULL);
 315         if (error == -1) {
 316                 kprintf("Failed to unload volume\n");
 317                 hammer_unlock(&hmp->blkmap_lock);
 318                 hammer_sync_unlock(trans);
 319                 return (error);
 320         }
 321
 322         volume = NULL;
 323         --hmp->nvolumes;
 324
 325         /*
 326          * Set each volume's new value of the vol_count field.
 327          */
 328         for (int vol_no = 0; vol_no < HAMMER_MAX_VOLUMES; ++vol_no) {
 329                 volume = hammer_get_volume(hmp, vol_no, &error);
 330                 if (volume == NULL && error == ENOENT) {
 331                         /*
 332                          * Skip unused volume numbers
 333                          */
 334                         error = 0;
 335                         continue;
 336                 }
 337
 338                 KKASSERT(volume != NULL && error == 0);
 339                 hammer_modify_volume_field(trans, volume, vol_count);
 340                 volume->ondisk->vol_count = hmp->nvolumes;
 341                 hammer_modify_volume_done(volume);
 342
 343                 /*
 344                  * Only changes to the header of the root volume
 345                  * are automatically flushed to disk. For all
 346                  * other volumes that we modify we do it here.
 347                  */
 348                 if (volume != trans->rootvol && volume->io.modified) {
 349                         hammer_crc_set_volume(volume->ondisk);
 350                         hammer_io_flush(&volume->io, 0);
 351                 }
 352
 353                 hammer_rel_volume(volume, 0);
 354         }
 355
 356         hammer_unlock(&hmp->blkmap_lock);
 357         hammer_sync_unlock(trans);
 358
 359         return (0);
 360 }
 361
 362
 363 /*
 364  * Iterate over all usable L1 entries of the volume and
 365  * the corresponding L2 entries.
 366  */
 367 static int
 368 hammer_iterate_l1l2_entries(hammer_transaction_t trans, hammer_volume_t volume,
 369         int (*callback)(hammer_transaction_t, hammer_buffer_t *,
 370                 struct hammer_blockmap_layer1*, struct hammer_blockmap_layer2 *,
 371                 hammer_off_t, int, void *),
 372         void *data)
 373 {
 374         struct hammer_mount *hmp = trans->hmp;
 375         hammer_blockmap_t freemap = &hmp->blockmap[HAMMER_ZONE_FREEMAP_INDEX];
 376         hammer_buffer_t buffer = NULL;
 377         int error = 0;
 378
 379         hammer_off_t phys_off;
 380         hammer_off_t block_off;
 381         hammer_off_t layer1_off;
 382         hammer_off_t layer2_off;
 383         hammer_off_t aligned_buf_end_off;
 384         struct hammer_blockmap_layer1 *layer1;
 385         struct hammer_blockmap_layer2 *layer2;
 386
 387         /*
 388          * Calculate the usable size of the volume, which
 389          * must be aligned at a bigblock (8 MB) boundary.
 390          */
 391         aligned_buf_end_off = (HAMMER_ENCODE_RAW_BUFFER(volume->ondisk->vol_no,
 392                 (volume->ondisk->vol_buf_end - volume->ondisk->vol_buf_beg)
 393                 & ~HAMMER_LARGEBLOCK_MASK64));
 394
 395         /*
 396          * Iterate the volume's address space in chunks of 4 TB, where each
 397          * chunk consists of at least one physically available 8 MB bigblock.
 398          *
 399          * For each chunk we need one L1 entry and one L2 bigblock.
 400          * We use the first bigblock of each chunk as L2 block.
 401          */
 402         for (phys_off = HAMMER_ENCODE_RAW_BUFFER(volume->ondisk->vol_no, 0);
 403              phys_off < aligned_buf_end_off;
 404              phys_off += HAMMER_BLOCKMAP_LAYER2) {
 405                 for (block_off = 0;
 406                      block_off < HAMMER_BLOCKMAP_LAYER2;
 407                      block_off += HAMMER_LARGEBLOCK_SIZE) {
 408                         layer2_off = phys_off +
 409                                 HAMMER_BLOCKMAP_LAYER2_OFFSET(block_off);
 410                         layer2 = hammer_bread(hmp, layer2_off, &error,
 411                                                 &buffer);
 412                         if (error)
 413                                 goto end;
 414
 415                         int zone;
 416                         if (block_off == 0) {
 417                                 /*
 418                                  * The first entry represents the L2 bigblock
 419                                  * itself.
 420                                  */
 421                                 zone = HAMMER_ZONE_FREEMAP_INDEX;
 422                         } else if (phys_off + block_off < aligned_buf_end_off) {
 423                                 /*
 424                                  * Available bigblock
 425                                  */
 426                                 zone = 0;
 427                         } else {
 428                                 /*
 429                                  * Bigblock outside of physically available
 430                                  * space
 431                                  */
 432                                 zone = HAMMER_ZONE_UNAVAIL_INDEX;
 433                         }
 434
 435                         error = callback(trans, &buffer, NULL, layer2, 0, zone,
 436                                         data);
 437                         if (error)
 438                                 goto end;
 439                 }
 440
 441                 layer1_off = freemap->phys_offset +
 442                                 HAMMER_BLOCKMAP_LAYER1_OFFSET(phys_off);
 443                 layer1 = hammer_bread(hmp, layer1_off, &error, &buffer);
 444                 if (error)
 445                         goto end;
 446
 447                 error = callback(trans, &buffer, layer1, NULL, phys_off, 0,
 448                                 data);
 449                 if (error)
 450                         goto end;
 451         }
 452
 453 end:
 454         if (buffer) {
 455                 hammer_rel_buffer(buffer, 0);
 456                 buffer = NULL;
 457         }
 458
 459         return error;
 460 }
 461
 462 struct format_bigblock_stat {
 463         uint64_t total_free_bigblocks;
 464         uint64_t free_bigblocks;
 465 };
 466
 467 static int
 468 format_callback(hammer_transaction_t trans, hammer_buffer_t *bufferp,
 469         struct hammer_blockmap_layer1 *layer1,
 470         struct hammer_blockmap_layer2 *layer2,
 471         hammer_off_t phys_off,
 472         int layer2_zone,
 473         void *data)
 474 {
 475         struct format_bigblock_stat *stat = (struct format_bigblock_stat*)data;
 476
 477         if (layer1) {
 478                 KKASSERT(layer1->phys_offset == HAMMER_BLOCKMAP_UNAVAIL);
 479
 480                 hammer_modify_buffer(trans, *bufferp, layer1, sizeof(*layer1));
 481                 bzero(layer1, sizeof(layer1));
 482                 layer1->phys_offset = phys_off;
 483                 layer1->blocks_free = stat->free_bigblocks;
 484                 layer1->layer1_crc = crc32(layer1, HAMMER_LAYER1_CRCSIZE);
 485                 hammer_modify_buffer_done(*bufferp);
 486
 487                 stat->total_free_bigblocks += stat->free_bigblocks;
 488                 stat->free_bigblocks = 0; /* reset */
 489         } else if (layer2) {
 490                 hammer_modify_buffer(trans, *bufferp, layer2, sizeof(*layer2));
 491                 bzero(layer2, sizeof(*layer2));
 492
 493                 layer2->zone = layer2_zone;
 494
 495                 switch (layer2->zone) {
 496                 case HAMMER_ZONE_FREEMAP_INDEX:
 497                         /*
 498                          * The first entry represents the L2 bigblock itself.
 499                          */
 500                         layer2->append_off = HAMMER_LARGEBLOCK_SIZE;
 501                         layer2->bytes_free = 0;
 502                         break;
 503
 504                 case 0:
 505                         /*
 506                          * Available bigblock
 507                          */
 508                         layer2->append_off = 0;
 509                         layer2->bytes_free = HAMMER_LARGEBLOCK_SIZE;
 510                         ++stat->free_bigblocks;
 511                         break;
 512
 513                 case HAMMER_ZONE_UNAVAIL_INDEX:
 514                         /*
 515                          * Bigblock outside of physically available space
 516                          */
 517                         layer2->append_off = HAMMER_LARGEBLOCK_SIZE;
 518                         layer2->bytes_free = 0;
 519                         break;
 520                 default:
 521                         KKASSERT(0);
 522                 }
 523
 524                 layer2->entry_crc = crc32(layer2, HAMMER_LAYER2_CRCSIZE);
 525                 hammer_modify_buffer_done(*bufferp);
 526         } else {
 527                 KKASSERT(0);
 528         }
 529
 530         return 0;
 531 }
 532
 533 static uint64_t
 534 hammer_format_freemap(hammer_transaction_t trans, hammer_volume_t volume)
 535 {
 536         int error = 0;
 537
 538         struct format_bigblock_stat stat;
 539         stat.total_free_bigblocks = 0;
 540         stat.free_bigblocks = 0;
 541
 542         error = hammer_iterate_l1l2_entries(trans, volume, format_callback,
 543                                         (void*)&stat);
 544         KKASSERT(error == 0);
 545
 546         return stat.total_free_bigblocks;
 547 }
 548
 549 static int
 550 free_callback(hammer_transaction_t trans, hammer_buffer_t *bufferp,
 551         struct hammer_blockmap_layer1 *layer1,
 552         struct hammer_blockmap_layer2 *layer2,
 553         hammer_off_t phys_off,
 554         int layer2_zone,
 555         void *data)
 556 {
 557         /*
 558          * No modifications to ondisk structures
 559          */
 560         int testonly = (data != NULL);
 561
 562         if (layer1) {
 563                 KKASSERT((int)HAMMER_VOL_DECODE(layer1->phys_offset) ==
 564                         trans->hmp->volume_to_remove);
 565
 566                 if (testonly)
 567                         return 0;
 568
 569                 /*
 570                  * Free the L1 entry
 571                  */
 572                 hammer_modify_buffer(trans, *bufferp, layer1, sizeof(*layer1));
 573                 bzero(layer1, sizeof(layer1));
 574                 layer1->phys_offset = HAMMER_BLOCKMAP_UNAVAIL;
 575                 layer1->layer1_crc = crc32(layer1, HAMMER_LAYER1_CRCSIZE);
 576                 hammer_modify_buffer_done(*bufferp);
 577
 578                 return 0;
 579         } else if (layer2) {
 580                 switch (layer2->zone) {
 581                 case HAMMER_ZONE_FREEMAP_INDEX:
 582                 case HAMMER_ZONE_UNAVAIL_INDEX:
 583                         return 0;
 584                 case 0:
 585                         if (layer2->append_off == 0 &&
 586                             layer2->bytes_free == HAMMER_LARGEBLOCK_SIZE) {
 587                                 return 0;
 588                         } else {
 589                                 return EBUSY;
 590                         }
 591                 default:
 592                         return EBUSY;
 593                 }
 594         } else {
 595                 KKASSERT(0);
 596         }
 597
 598         return EINVAL;
 599 }
 600
 601 static int
 602 hammer_free_freemap(hammer_transaction_t trans, hammer_volume_t volume)
 603 {
 604         int error;
 605         error = hammer_iterate_l1l2_entries(trans, volume, free_callback,
 606                                             (void*)1);
 607         if (error)
 608                 return error;
 609
 610         error = hammer_iterate_l1l2_entries(trans, volume, free_callback, NULL);
 611         return error;
 612 }
 613
 614 /************************************************************************
 615  *                              MISC                                    *
 616  ************************************************************************
 617  */
 618
 619 static int
 620 hammer_setup_device(struct vnode **devvpp, const char *dev_path, int ronly)
 621 {
 622         int error;
 623         struct nlookupdata nd;
 624
 625         /*
 626          * Get the device vnode
 627          */
 628         if (*devvpp == NULL) {
 629                 error = nlookup_init(&nd, dev_path, UIO_SYSSPACE, NLC_FOLLOW);
 630                 if (error == 0)
 631                         error = nlookup(&nd);
 632                 if (error == 0)
 633                         error = cache_vref(&nd.nl_nch, nd.nl_cred, devvpp);
 634                 nlookup_done(&nd);
 635         } else {
 636                 error = 0;
 637         }
 638
 639         if (error == 0) {
 640                 if (vn_isdisk(*devvpp, &error)) {
 641                         error = vfs_mountedon(*devvpp);
 642                 }
 643         }
 644         if (error == 0 && vcount(*devvpp) > 0)
 645                 error = EBUSY;
 646         if (error == 0) {
 647                 vn_lock(*devvpp, LK_EXCLUSIVE | LK_RETRY);
 648                 error = vinvalbuf(*devvpp, V_SAVE, 0, 0);
 649                 if (error == 0) {
 650                         error = VOP_OPEN(*devvpp,
 651                                          (ronly ? FREAD : FREAD|FWRITE),
 652                                          FSCRED, NULL);
 653                 }
 654                 vn_unlock(*devvpp);
 655         }
 656         if (error && *devvpp) {
 657                 vrele(*devvpp);
 658                 *devvpp = NULL;
 659         }
 660         return (error);
 661 }
 662
 663 static void
 664 hammer_close_device(struct vnode **devvpp, int ronly)
 665 {
 666         VOP_CLOSE(*devvpp, (ronly ? FREAD : FREAD|FWRITE));
 667         if (*devvpp) {
 668                 vinvalbuf(*devvpp, ronly ? 0 : V_SAVE, 0, 0);
 669                 vrele(*devvpp);
 670                 *devvpp = NULL;
 671         }
 672 }
 673
 674 static int
 675 hammer_format_volume_header(struct hammer_mount *hmp, struct vnode *devvp,
 676         const char *vol_name, int vol_no, int vol_count,
 677         int64_t vol_size, int64_t boot_area_size, int64_t mem_area_size)
 678 {
 679         struct buf *bp = NULL;
 680         struct hammer_volume_ondisk *ondisk;
 681         int error;
 682
 683         /*
 684          * Extract the volume number from the volume header and do various
 685          * sanity checks.
 686          */
 687         KKASSERT(HAMMER_BUFSIZE >= sizeof(struct hammer_volume_ondisk));
 688         error = bread(devvp, 0LL, HAMMER_BUFSIZE, &bp);
 689         if (error || bp->b_bcount < sizeof(struct hammer_volume_ondisk))
 690                 goto late_failure;
 691
 692         ondisk = (struct hammer_volume_ondisk*) bp->b_data;
 693
 694         /*
 695          * Note that we do NOT allow to use a device that contains
 696          * a valid HAMMER signature. It has to be cleaned up with dd
 697          * before.
 698          */
 699         if (ondisk->vol_signature == HAMMER_FSBUF_VOLUME) {
 700                 kprintf("hammer_volume_add: Formatting of valid HAMMER volume "
 701                         "%s denied. Erase with dd!\n", vol_name);
 702                 error = EFTYPE;
 703                 goto late_failure;
 704         }
 705
 706         bzero(ondisk, sizeof(struct hammer_volume_ondisk));
 707         ksnprintf(ondisk->vol_name, sizeof(ondisk->vol_name), "%s", vol_name);
 708         ondisk->vol_fstype = hmp->rootvol->ondisk->vol_fstype;
 709         ondisk->vol_signature = HAMMER_FSBUF_VOLUME;
 710         ondisk->vol_fsid = hmp->fsid;
 711         ondisk->vol_rootvol = hmp->rootvol->vol_no;
 712         ondisk->vol_no = vol_no;
 713         ondisk->vol_count = vol_count;
 714         ondisk->vol_version = hmp->version;
 715
 716         /*
 717          * Reserve space for (future) header junk, setup our poor-man's
 718          * bigblock allocator.
 719          */
 720         int64_t vol_alloc = HAMMER_BUFSIZE * 16;
 721
 722         ondisk->vol_bot_beg = vol_alloc;
 723         vol_alloc += boot_area_size;
 724         ondisk->vol_mem_beg = vol_alloc;
 725         vol_alloc += mem_area_size;
 726
 727         /*
 728          * The remaining area is the zone 2 buffer allocation area.  These
 729          * buffers
 730          */
 731         ondisk->vol_buf_beg = vol_alloc;
 732         ondisk->vol_buf_end = vol_size & ~(int64_t)HAMMER_BUFMASK;
 733
 734         if (ondisk->vol_buf_end < ondisk->vol_buf_beg) {
 735                 kprintf("volume %d %s is too small to hold the volume header",
 736                      ondisk->vol_no, ondisk->vol_name);
 737                 error = EFTYPE;
 738                 goto late_failure;
 739         }
 740
 741         ondisk->vol_nblocks = (ondisk->vol_buf_end - ondisk->vol_buf_beg) /
 742                               HAMMER_BUFSIZE;
 743         ondisk->vol_blocksize = HAMMER_BUFSIZE;
 744
 745         /*
 746          * Write volume header to disk
 747          */
 748         error = bwrite(bp);
 749         bp = NULL;
 750
 751 late_failure:
 752         if (bp)
 753                 brelse(bp);
 754         return (error);
 755 }