sys/vfs/hammer/hammer_reblock.c

   1 /*
   2  * Copyright (c) 2008-2012 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  * HAMMER reblocker - This code frees up fragmented physical space
  36  *
  37  * HAMMER only keeps track of free space on a big-block basis.  A big-block
  38  * containing holes can only be freed by migrating the remaining data in
  39  * that big-block into a new big-block, then freeing the big-block.
  40  *
  41  * This function is called from an ioctl or via the hammer support thread.
  42  */
  43
  44 #include "hammer.h"
  45
  46 static int hammer_reblock_helper(struct hammer_ioc_reblock *reblock,
  47                                  hammer_cursor_t cursor,
  48                                  hammer_btree_elm_t elm);
  49 static int hammer_reblock_data(struct hammer_ioc_reblock *reblock,
  50                                 hammer_cursor_t cursor, hammer_btree_elm_t elm);
  51 static int hammer_reblock_leaf_node(struct hammer_ioc_reblock *reblock,
  52                                 hammer_cursor_t cursor, hammer_btree_elm_t elm);
  53 static int hammer_reblock_int_node(struct hammer_ioc_reblock *reblock,
  54                                 hammer_cursor_t cursor, hammer_btree_elm_t elm);
  55
  56 int
  57 hammer_ioc_reblock(hammer_transaction_t trans, hammer_inode_t ip,
  58                    struct hammer_ioc_reblock *reblock)
  59 {
  60         struct hammer_cursor cursor;
  61         hammer_btree_elm_t elm;
  62         int checkspace_count;
  63         int error;
  64         int seq;
  65         int slop;
  66         u_int32_t key_end_localization;
  67
  68         if ((reblock->key_beg.localization | reblock->key_end.localization) &
  69             HAMMER_LOCALIZE_PSEUDOFS_MASK) {
  70                 return(EINVAL);
  71         }
  72         if (reblock->key_beg.obj_id >= reblock->key_end.obj_id)
  73                 return(EINVAL);
  74         if (reblock->free_level < 0 ||
  75             reblock->free_level > HAMMER_BIGBLOCK_SIZE)
  76                 return(EINVAL);
  77
  78         /*
  79          * A fill_percentage <= 20% is considered an emergency.  free_level is
  80          * inverted from fill_percentage.
  81          */
  82         if (reblock->free_level >= HAMMER_BIGBLOCK_SIZE * 8 / 10)
  83                 slop = HAMMER_CHKSPC_EMERGENCY;
  84         else
  85                 slop = HAMMER_CHKSPC_REBLOCK;
  86
  87         /*
  88          * Ioctl caller has only set localization type to reblock.
  89          * Initialize cursor key localization with ip localization.
  90          */
  91         reblock->key_cur = reblock->key_beg;
  92         reblock->key_cur.localization &= HAMMER_LOCALIZE_MASK;
  93         reblock->key_cur.localization += ip->obj_localization;
  94
  95         key_end_localization = reblock->key_end.localization;
  96         key_end_localization &= HAMMER_LOCALIZE_MASK;
  97         key_end_localization += ip->obj_localization;
  98
  99         checkspace_count = 0;
 100         seq = trans->hmp->flusher.done;
 101 retry:
 102         error = hammer_init_cursor(trans, &cursor, NULL, NULL);
 103         if (error) {
 104                 hammer_done_cursor(&cursor);
 105                 goto failed;
 106         }
 107         cursor.key_beg.localization = reblock->key_cur.localization;
 108         cursor.key_beg.obj_id = reblock->key_cur.obj_id;
 109         cursor.key_beg.key = HAMMER_MIN_KEY;
 110         cursor.key_beg.create_tid = 1;
 111         cursor.key_beg.delete_tid = 0;
 112         cursor.key_beg.rec_type = HAMMER_MIN_RECTYPE;
 113         cursor.key_beg.obj_type = 0;
 114
 115         cursor.key_end.localization = key_end_localization;
 116         cursor.key_end.obj_id = reblock->key_end.obj_id;
 117         cursor.key_end.key = HAMMER_MAX_KEY;
 118         cursor.key_end.create_tid = HAMMER_MAX_TID - 1;
 119         cursor.key_end.delete_tid = 0;
 120         cursor.key_end.rec_type = HAMMER_MAX_RECTYPE;
 121         cursor.key_end.obj_type = 0;
 122
 123         cursor.flags |= HAMMER_CURSOR_END_INCLUSIVE;
 124         cursor.flags |= HAMMER_CURSOR_BACKEND;
 125         cursor.flags |= HAMMER_CURSOR_NOSWAPCACHE;
 126
 127         /*
 128          * This flag allows the btree scan code to return internal nodes,
 129          * so we can reblock them in addition to the leafs.  Only specify it
 130          * if we intend to reblock B-Tree nodes.
 131          */
 132         if (reblock->head.flags & HAMMER_IOC_DO_BTREE)
 133                 cursor.flags |= HAMMER_CURSOR_REBLOCKING;
 134
 135         error = hammer_btree_first(&cursor);
 136         while (error == 0) {
 137                 /*
 138                  * Internal or Leaf node
 139                  */
 140                 KKASSERT(cursor.index < cursor.node->ondisk->count);
 141                 elm = &cursor.node->ondisk->elms[cursor.index];
 142                 reblock->key_cur.obj_id = elm->base.obj_id;
 143                 reblock->key_cur.localization = elm->base.localization;
 144
 145                 /*
 146                  * Yield to more important tasks
 147                  */
 148                 if ((error = hammer_signal_check(trans->hmp)) != 0)
 149                         break;
 150
 151                 /*
 152                  * If there is insufficient free space it may be due to
 153                  * reserved bigblocks, which flushing might fix.
 154                  *
 155                  * We must force a retest in case the unlocked cursor is
 156                  * moved to the end of the leaf, or moved to an internal
 157                  * node.
 158                  *
 159                  * WARNING: See warnings in hammer_unlock_cursor() function.
 160                  */
 161                 if (hammer_checkspace(trans->hmp, slop)) {
 162                         if (++checkspace_count == 10) {
 163                                 error = ENOSPC;
 164                                 break;
 165                         }
 166                         hammer_unlock_cursor(&cursor);
 167                         cursor.flags |= HAMMER_CURSOR_RETEST;
 168                         hammer_flusher_wait(trans->hmp, seq);
 169                         hammer_lock_cursor(&cursor);
 170                         seq = hammer_flusher_async(trans->hmp, NULL);
 171                         goto skip;
 172                 }
 173
 174                 /*
 175                  * Acquiring the sync_lock prevents the operation from
 176                  * crossing a synchronization boundary.
 177                  *
 178                  * NOTE: cursor.node may have changed on return.
 179                  *
 180                  * WARNING: See warnings in hammer_unlock_cursor() function.
 181                  */
 182                 hammer_sync_lock_sh(trans);
 183                 error = hammer_reblock_helper(reblock, &cursor, elm);
 184                 hammer_sync_unlock(trans);
 185
 186                 while (hammer_flusher_meta_halflimit(trans->hmp) ||
 187                        hammer_flusher_undo_exhausted(trans, 2)) {
 188                         hammer_unlock_cursor(&cursor);
 189                         hammer_flusher_wait(trans->hmp, seq);
 190                         hammer_lock_cursor(&cursor);
 191                         seq = hammer_flusher_async_one(trans->hmp);
 192                 }
 193
 194                 /*
 195                  * Setup for iteration, our cursor flags may be modified by
 196                  * other threads while we are unlocked.
 197                  */
 198                 cursor.flags |= HAMMER_CURSOR_ATEDISK;
 199
 200                 /*
 201                  * We allocate data buffers, which atm we don't track
 202                  * dirty levels for because we allow the kernel to write
 203                  * them.  But if we allocate too many we can still deadlock
 204                  * the buffer cache.
 205                  *
 206                  * WARNING: See warnings in hammer_unlock_cursor() function.
 207                  *          (The cursor's node and element may change!)
 208                  */
 209                 if (bd_heatup()) {
 210                         hammer_unlock_cursor(&cursor);
 211                         bwillwrite(HAMMER_XBUFSIZE);
 212                         hammer_lock_cursor(&cursor);
 213                 }
 214                 vm_wait_nominal();
 215 skip:
 216                 if (error == 0) {
 217                         error = hammer_btree_iterate(&cursor);
 218                 }
 219         }
 220         if (error == ENOENT)
 221                 error = 0;
 222         hammer_done_cursor(&cursor);
 223         if (error == EWOULDBLOCK) {
 224                 hammer_flusher_sync(trans->hmp);
 225                 goto retry;
 226         }
 227         if (error == EDEADLK)
 228                 goto retry;
 229         if (error == EINTR) {
 230                 reblock->head.flags |= HAMMER_IOC_HEAD_INTR;
 231                 error = 0;
 232         }
 233 failed:
 234         reblock->key_cur.localization &= HAMMER_LOCALIZE_MASK;
 235         return(error);
 236 }
 237
 238 /*
 239  * Reblock the B-Tree (leaf) node, record, and/or data if necessary.
 240  *
 241  * XXX We have no visibility into internal B-Tree nodes at the moment,
 242  * only leaf nodes.
 243  */
 244 static int
 245 hammer_reblock_helper(struct hammer_ioc_reblock *reblock,
 246                       hammer_cursor_t cursor, hammer_btree_elm_t elm)
 247 {
 248         hammer_mount_t hmp;
 249         hammer_off_t tmp_offset;
 250         hammer_node_ondisk_t ondisk;
 251         struct hammer_btree_leaf_elm leaf;
 252         int error;
 253         int bytes;
 254         int cur;
 255         int iocflags;
 256
 257         error = 0;
 258         hmp = cursor->trans->hmp;
 259
 260         /*
 261          * Reblock data.  Note that data embedded in a record is reblocked
 262          * by the record reblock code.  Data processing only occurs at leaf
 263          * nodes and for RECORD element types.
 264          */
 265         if (cursor->node->ondisk->type != HAMMER_BTREE_TYPE_LEAF)
 266                 goto skip;
 267         if (elm->leaf.base.btype != HAMMER_BTREE_TYPE_RECORD)
 268                 return(0);
 269         tmp_offset = elm->leaf.data_offset;
 270         if (tmp_offset == 0)
 271                 goto skip;
 272         if (error)
 273                 goto skip;
 274
 275         /*
 276          * NOTE: Localization restrictions may also have been set-up, we can't
 277          *       just set the match flags willy-nilly here.
 278          */
 279         switch(elm->leaf.base.rec_type) {
 280         case HAMMER_RECTYPE_INODE:
 281         case HAMMER_RECTYPE_SNAPSHOT:
 282         case HAMMER_RECTYPE_CONFIG:
 283                 iocflags = HAMMER_IOC_DO_INODES;
 284                 break;
 285         case HAMMER_RECTYPE_EXT:
 286         case HAMMER_RECTYPE_FIX:
 287         case HAMMER_RECTYPE_PFS:
 288         case HAMMER_RECTYPE_DIRENTRY:
 289                 iocflags = HAMMER_IOC_DO_DIRS;
 290                 break;
 291         case HAMMER_RECTYPE_DATA:
 292         case HAMMER_RECTYPE_DB:
 293                 iocflags = HAMMER_IOC_DO_DATA;
 294                 break;
 295         default:
 296                 iocflags = 0;
 297                 break;
 298         }
 299         if (reblock->head.flags & iocflags) {
 300                 ++reblock->data_count;
 301                 reblock->data_byte_count += elm->leaf.data_len;
 302                 bytes = hammer_blockmap_getfree(hmp, tmp_offset, &cur, &error);
 303                 if (hammer_debug_general & 0x4000)
 304                         kprintf("D %6d/%d\n", bytes, reblock->free_level);
 305                 if (error == 0 && (cur == 0 || reblock->free_level == 0) &&
 306                     bytes >= reblock->free_level) {
 307                         /*
 308                          * This is nasty, the uncache code may have to get
 309                          * vnode locks and because of that we can't hold
 310                          * the cursor locked.
 311                          *
 312                          * WARNING: See warnings in hammer_unlock_cursor()
 313                          *          function.
 314                          */
 315                         leaf = elm->leaf;
 316                         hammer_unlock_cursor(cursor);
 317                         hammer_io_direct_uncache(hmp, &leaf);
 318                         hammer_lock_cursor(cursor);
 319
 320                         /*
 321                          * elm may have become stale or invalid, reload it.
 322                          * ondisk variable is temporary only.  Note that
 323                          * cursor->node and thus cursor->node->ondisk may
 324                          * also changed.
 325                          */
 326                         ondisk = cursor->node->ondisk;
 327                         elm = &ondisk->elms[cursor->index];
 328                         if (cursor->flags & HAMMER_CURSOR_RETEST) {
 329                                 kprintf("hammer: debug: retest on "
 330                                         "reblocker uncache\n");
 331                                 error = EDEADLK;
 332                         } else if (ondisk->type != HAMMER_BTREE_TYPE_LEAF ||
 333                                    cursor->index >= ondisk->count) {
 334                                 kprintf("hammer: debug: shifted on "
 335                                         "reblocker uncache\n");
 336                                 error = EDEADLK;
 337                         } else if (bcmp(&elm->leaf, &leaf, sizeof(leaf))) {
 338                                 kprintf("hammer: debug: changed on "
 339                                         "reblocker uncache\n");
 340                                 error = EDEADLK;
 341                         }
 342                         if (error == 0)
 343                                 error = hammer_cursor_upgrade(cursor);
 344                         if (error == 0) {
 345                                 KKASSERT(cursor->index < ondisk->count);
 346                                 error = hammer_reblock_data(reblock,
 347                                                             cursor, elm);
 348                         }
 349                         if (error == 0) {
 350                                 ++reblock->data_moves;
 351                                 reblock->data_byte_moves += elm->leaf.data_len;
 352                         }
 353                 }
 354         }
 355
 356 skip:
 357         /*
 358          * Reblock a B-Tree internal or leaf node.  A leaf node is reblocked
 359          * on initial entry only (element 0).  An internal node is reblocked
 360          * when entered upward from its first leaf node only (also element 0).
 361          * Further revisits of the internal node (index > 0) are ignored.
 362          */
 363         tmp_offset = cursor->node->node_offset;
 364         if (cursor->index == 0 &&
 365             error == 0 && (reblock->head.flags & HAMMER_IOC_DO_BTREE)) {
 366                 ++reblock->btree_count;
 367                 bytes = hammer_blockmap_getfree(hmp, tmp_offset, &cur, &error);
 368                 if (hammer_debug_general & 0x4000)
 369                         kprintf("B %6d/%d\n", bytes, reblock->free_level);
 370                 if (error == 0 && (cur == 0 || reblock->free_level == 0) &&
 371                     bytes >= reblock->free_level) {
 372                         error = hammer_cursor_upgrade(cursor);
 373                         if (error == 0) {
 374                                 if (cursor->parent) {
 375                                         KKASSERT(cursor->parent_index <
 376                                                  cursor->parent->ondisk->count);
 377                                         elm = &cursor->parent->ondisk->elms[cursor->parent_index];
 378                                 } else {
 379                                         elm = NULL;
 380                                 }
 381                                 switch(cursor->node->ondisk->type) {
 382                                 case HAMMER_BTREE_TYPE_LEAF:
 383                                         error = hammer_reblock_leaf_node(
 384                                                         reblock, cursor, elm);
 385                                         break;
 386                                 case HAMMER_BTREE_TYPE_INTERNAL:
 387                                         error = hammer_reblock_int_node(
 388                                                         reblock, cursor, elm);
 389                                         break;
 390                                 default:
 391                                         panic("Illegal B-Tree node type");
 392                                 }
 393                         }
 394                         if (error == 0) {
 395                                 ++reblock->btree_moves;
 396                         }
 397                 }
 398         }
 399
 400         hammer_cursor_downgrade(cursor);
 401         return(error);
 402 }
 403
 404 /*
 405  * Reblock a record's data.  Both the B-Tree element and record pointers
 406  * to the data must be adjusted.
 407  */
 408 static int
 409 hammer_reblock_data(struct hammer_ioc_reblock *reblock,
 410                     hammer_cursor_t cursor, hammer_btree_elm_t elm)
 411 {
 412         struct hammer_buffer *data_buffer = NULL;
 413         hammer_off_t ndata_offset;
 414         int error;
 415         void *ndata;
 416
 417         error = hammer_btree_extract(cursor, HAMMER_CURSOR_GET_DATA |
 418                                              HAMMER_CURSOR_GET_LEAF);
 419         if (error)
 420                 return (error);
 421         ndata = hammer_alloc_data(cursor->trans, elm->leaf.data_len,
 422                                   elm->leaf.base.rec_type,
 423                                   &ndata_offset, &data_buffer,
 424                                   0, &error);
 425         if (error)
 426                 goto done;
 427         hammer_io_notmeta(data_buffer);
 428
 429         /*
 430          * Move the data.  Note that we must invalidate any cached
 431          * data buffer in the cursor before calling blockmap_free.
 432          * The blockmap_free may free up the entire big-block and
 433          * will not be able to invalidate it if the cursor is holding
 434          * a data buffer cached in that big block.
 435          */
 436         hammer_modify_buffer(cursor->trans, data_buffer, NULL, 0);
 437         bcopy(cursor->data, ndata, elm->leaf.data_len);
 438         hammer_modify_buffer_done(data_buffer);
 439         hammer_cursor_invalidate_cache(cursor);
 440
 441         hammer_blockmap_free(cursor->trans,
 442                              elm->leaf.data_offset, elm->leaf.data_len);
 443
 444         hammer_modify_node(cursor->trans, cursor->node,
 445                            &elm->leaf.data_offset, sizeof(hammer_off_t));
 446         elm->leaf.data_offset = ndata_offset;
 447         hammer_modify_node_done(cursor->node);
 448
 449 done:
 450         if (data_buffer)
 451                 hammer_rel_buffer(data_buffer, 0);
 452         return (error);
 453 }
 454
 455 /*
 456  * Reblock a B-Tree leaf node.  The parent must be adjusted to point to
 457  * the new copy of the leaf node.
 458  *
 459  * elm is a pointer to the parent element pointing at cursor.node.
 460  */
 461 static int
 462 hammer_reblock_leaf_node(struct hammer_ioc_reblock *reblock,
 463                          hammer_cursor_t cursor, hammer_btree_elm_t elm)
 464 {
 465         hammer_node_t onode;
 466         hammer_node_t nnode;
 467         int error;
 468
 469         /*
 470          * Don't supply a hint when allocating the leaf.  Fills are done
 471          * from the leaf upwards.
 472          */
 473         onode = cursor->node;
 474         nnode = hammer_alloc_btree(cursor->trans, 0, &error);
 475
 476         if (nnode == NULL)
 477                 return (error);
 478
 479         /*
 480          * Move the node
 481          */
 482         hammer_lock_ex(&nnode->lock);
 483         hammer_modify_node_noundo(cursor->trans, nnode);
 484         bcopy(onode->ondisk, nnode->ondisk, sizeof(*nnode->ondisk));
 485
 486         if (elm) {
 487                 /*
 488                  * We are not the root of the B-Tree
 489                  */
 490                 hammer_modify_node(cursor->trans, cursor->parent,
 491                                    &elm->internal.subtree_offset,
 492                                    sizeof(elm->internal.subtree_offset));
 493                 elm->internal.subtree_offset = nnode->node_offset;
 494                 hammer_modify_node_done(cursor->parent);
 495         } else {
 496                 /*
 497                  * We are the root of the B-Tree
 498                  */
 499                 hammer_volume_t volume;
 500
 501                 volume = hammer_get_root_volume(cursor->trans->hmp, &error);
 502                 KKASSERT(error == 0);
 503
 504                 hammer_modify_volume_field(cursor->trans, volume,
 505                                            vol0_btree_root);
 506                 volume->ondisk->vol0_btree_root = nnode->node_offset;
 507                 hammer_modify_volume_done(volume);
 508                 hammer_rel_volume(volume, 0);
 509         }
 510
 511         hammer_cursor_replaced_node(onode, nnode);
 512         hammer_delete_node(cursor->trans, onode);
 513
 514         if (hammer_debug_general & 0x4000) {
 515                 kprintf("REBLOCK LNODE %016llx -> %016llx\n",
 516                         (long long)onode->node_offset,
 517                         (long long)nnode->node_offset);
 518         }
 519         hammer_modify_node_done(nnode);
 520         cursor->node = nnode;
 521
 522         hammer_unlock(&onode->lock);
 523         hammer_rel_node(onode);
 524
 525         return (error);
 526 }
 527
 528 /*
 529  * Reblock a B-Tree internal node.  The parent must be adjusted to point to
 530  * the new copy of the internal node, and the node's children's parent
 531  * pointers must also be adjusted to point to the new copy.
 532  *
 533  * elm is a pointer to the parent element pointing at cursor.node.
 534  */
 535 static int
 536 hammer_reblock_int_node(struct hammer_ioc_reblock *reblock,
 537                          hammer_cursor_t cursor, hammer_btree_elm_t elm)
 538 {
 539         struct hammer_node_lock lockroot;
 540         hammer_node_t onode;
 541         hammer_node_t nnode;
 542         int error;
 543         int i;
 544
 545         hammer_node_lock_init(&lockroot, cursor->node);
 546         error = hammer_btree_lock_children(cursor, 1, &lockroot, NULL);
 547         if (error)
 548                 goto done;
 549
 550         onode = cursor->node;
 551         nnode = hammer_alloc_btree(cursor->trans, 0, &error);
 552
 553         if (nnode == NULL)
 554                 goto done;
 555
 556         /*
 557          * Move the node.  Adjust the parent's pointer to us first.
 558          */
 559         hammer_lock_ex(&nnode->lock);
 560         hammer_modify_node_noundo(cursor->trans, nnode);
 561         bcopy(onode->ondisk, nnode->ondisk, sizeof(*nnode->ondisk));
 562
 563         if (elm) {
 564                 /*
 565                  * We are not the root of the B-Tree
 566                  */
 567                 hammer_modify_node(cursor->trans, cursor->parent,
 568                                    &elm->internal.subtree_offset,
 569                                    sizeof(elm->internal.subtree_offset));
 570                 elm->internal.subtree_offset = nnode->node_offset;
 571                 hammer_modify_node_done(cursor->parent);
 572         } else {
 573                 /*
 574                  * We are the root of the B-Tree
 575                  */
 576                 hammer_volume_t volume;
 577
 578                 volume = hammer_get_root_volume(cursor->trans->hmp, &error);
 579                 KKASSERT(error == 0);
 580
 581                 hammer_modify_volume_field(cursor->trans, volume,
 582                                            vol0_btree_root);
 583                 volume->ondisk->vol0_btree_root = nnode->node_offset;
 584                 hammer_modify_volume_done(volume);
 585                 hammer_rel_volume(volume, 0);
 586         }
 587
 588         /*
 589          * Now adjust our children's pointers to us.
 590          */
 591         for (i = 0; i < nnode->ondisk->count; ++i) {
 592                 elm = &nnode->ondisk->elms[i];
 593                 error = btree_set_parent(cursor->trans, nnode, elm);
 594                 if (error)
 595                         panic("reblock internal node: fixup problem");
 596         }
 597
 598         /*
 599          * Clean up.
 600          *
 601          * The new node replaces the current node in the cursor.  The cursor
 602          * expects it to be locked so leave it locked.  Discard onode.
 603          */
 604         hammer_cursor_replaced_node(onode, nnode);
 605         hammer_delete_node(cursor->trans, onode);
 606
 607         if (hammer_debug_general & 0x4000) {
 608                 kprintf("REBLOCK INODE %016llx -> %016llx\n",
 609                         (long long)onode->node_offset,
 610                         (long long)nnode->node_offset);
 611         }
 612         hammer_modify_node_done(nnode);
 613         cursor->node = nnode;
 614
 615         hammer_unlock(&onode->lock);
 616         hammer_rel_node(onode);
 617
 618 done:
 619         hammer_btree_unlock_children(cursor->trans->hmp, &lockroot, NULL);
 620         return (error);
 621 }
 622