sys/vfs/hammer/hammer_ondisk.c

   1 /*
   2  * Copyright (c) 2007-2008 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  * $DragonFly: src/sys/vfs/hammer/hammer_ondisk.c,v 1.59 2008/06/18 01:13:30 dillon Exp $
  35  */
  36 /*
  37  * Manage HAMMER's on-disk structures.  These routines are primarily
  38  * responsible for interfacing with the kernel's I/O subsystem and for
  39  * managing in-memory structures.
  40  */
  41
  42 #include "hammer.h"
  43 #include <sys/fcntl.h>
  44 #include <sys/nlookup.h>
  45 #include <sys/buf.h>
  46 #include <sys/buf2.h>
  47
  48 static void hammer_free_volume(hammer_volume_t volume);
  49 static int hammer_load_volume(hammer_volume_t volume);
  50 static int hammer_load_buffer(hammer_buffer_t buffer, int isnew);
  51 static int hammer_load_node(hammer_node_t node, int isnew);
  52
  53 /*
  54  * Red-Black tree support for various structures
  55  */
  56 int
  57 hammer_ino_rb_compare(hammer_inode_t ip1, hammer_inode_t ip2)
  58 {
  59         if (ip1->obj_id < ip2->obj_id)
  60                 return(-1);
  61         if (ip1->obj_id > ip2->obj_id)
  62                 return(1);
  63         if (ip1->obj_asof < ip2->obj_asof)
  64                 return(-1);
  65         if (ip1->obj_asof > ip2->obj_asof)
  66                 return(1);
  67         return(0);
  68 }
  69
  70 static int
  71 hammer_inode_info_cmp(hammer_inode_info_t info, hammer_inode_t ip)
  72 {
  73         if (info->obj_id < ip->obj_id)
  74                 return(-1);
  75         if (info->obj_id > ip->obj_id)
  76                 return(1);
  77         if (info->obj_asof < ip->obj_asof)
  78                 return(-1);
  79         if (info->obj_asof > ip->obj_asof)
  80                 return(1);
  81         return(0);
  82 }
  83
  84 static int
  85 hammer_vol_rb_compare(hammer_volume_t vol1, hammer_volume_t vol2)
  86 {
  87         if (vol1->vol_no < vol2->vol_no)
  88                 return(-1);
  89         if (vol1->vol_no > vol2->vol_no)
  90                 return(1);
  91         return(0);
  92 }
  93
  94 static int
  95 hammer_buf_rb_compare(hammer_buffer_t buf1, hammer_buffer_t buf2)
  96 {
  97         if (buf1->zoneX_offset < buf2->zoneX_offset)
  98                 return(-1);
  99         if (buf1->zoneX_offset > buf2->zoneX_offset)
 100                 return(1);
 101         return(0);
 102 }
 103
 104 static int
 105 hammer_nod_rb_compare(hammer_node_t node1, hammer_node_t node2)
 106 {
 107         if (node1->node_offset < node2->node_offset)
 108                 return(-1);
 109         if (node1->node_offset > node2->node_offset)
 110                 return(1);
 111         return(0);
 112 }
 113
 114 /*
 115  * Note: The lookup function for hammer_ino_rb_tree winds up being named
 116  * hammer_ino_rb_tree_RB_LOOKUP_INFO(root, info).  The other lookup
 117  * functions are normal, e.g. hammer_buf_rb_tree_RB_LOOKUP(root, zone2_offset).
 118  */
 119 RB_GENERATE(hammer_ino_rb_tree, hammer_inode, rb_node, hammer_ino_rb_compare);
 120 RB_GENERATE_XLOOKUP(hammer_ino_rb_tree, INFO, hammer_inode, rb_node,
 121                 hammer_inode_info_cmp, hammer_inode_info_t);
 122 RB_GENERATE2(hammer_vol_rb_tree, hammer_volume, rb_node,
 123              hammer_vol_rb_compare, int32_t, vol_no);
 124 RB_GENERATE2(hammer_buf_rb_tree, hammer_buffer, rb_node,
 125              hammer_buf_rb_compare, hammer_off_t, zoneX_offset);
 126 RB_GENERATE2(hammer_nod_rb_tree, hammer_node, rb_node,
 127              hammer_nod_rb_compare, hammer_off_t, node_offset);
 128
 129 /************************************************************************
 130  *                              VOLUMES                                 *
 131  ************************************************************************
 132  *
 133  * Load a HAMMER volume by name.  Returns 0 on success or a positive error
 134  * code on failure.  Volumes must be loaded at mount time, get_volume() will
 135  * not load a new volume.
 136  *
 137  * Calls made to hammer_load_volume() or single-threaded
 138  */
 139 int
 140 hammer_install_volume(struct hammer_mount *hmp, const char *volname)
 141 {
 142         struct mount *mp;
 143         hammer_volume_t volume;
 144         struct hammer_volume_ondisk *ondisk;
 145         struct nlookupdata nd;
 146         struct buf *bp = NULL;
 147         int error;
 148         int ronly;
 149         int setmp = 0;
 150
 151         mp = hmp->mp;
 152         ronly = ((mp->mnt_flag & MNT_RDONLY) ? 1 : 0);
 153
 154         /*
 155          * Allocate a volume structure
 156          */
 157         ++hammer_count_volumes;
 158         volume = kmalloc(sizeof(*volume), M_HAMMER, M_WAITOK|M_ZERO);
 159         volume->vol_name = kstrdup(volname, M_HAMMER);
 160         hammer_io_init(&volume->io, hmp, HAMMER_STRUCTURE_VOLUME);
 161         volume->io.offset = 0LL;
 162
 163         /*
 164          * Get the device vnode
 165          */
 166         error = nlookup_init(&nd, volume->vol_name, UIO_SYSSPACE, NLC_FOLLOW);
 167         if (error == 0)
 168                 error = nlookup(&nd);
 169         if (error == 0)
 170                 error = cache_vref(&nd.nl_nch, nd.nl_cred, &volume->devvp);
 171         nlookup_done(&nd);
 172         if (error == 0) {
 173                 if (vn_isdisk(volume->devvp, &error)) {
 174                         error = vfs_mountedon(volume->devvp);
 175                 }
 176         }
 177         if (error == 0 &&
 178             count_udev(volume->devvp->v_umajor, volume->devvp->v_uminor) > 0) {
 179                 error = EBUSY;
 180         }
 181         if (error == 0) {
 182                 vn_lock(volume->devvp, LK_EXCLUSIVE | LK_RETRY);
 183                 error = vinvalbuf(volume->devvp, V_SAVE, 0, 0);
 184                 if (error == 0) {
 185                         error = VOP_OPEN(volume->devvp,
 186                                          (ronly ? FREAD : FREAD|FWRITE),
 187                                          FSCRED, NULL);
 188                 }
 189                 vn_unlock(volume->devvp);
 190         }
 191         if (error) {
 192                 hammer_free_volume(volume);
 193                 return(error);
 194         }
 195         volume->devvp->v_rdev->si_mountpoint = mp;
 196         setmp = 1;
 197
 198         /*
 199          * Extract the volume number from the volume header and do various
 200          * sanity checks.
 201          */
 202         error = bread(volume->devvp, 0LL, HAMMER_BUFSIZE, &bp);
 203         if (error)
 204                 goto late_failure;
 205         ondisk = (void *)bp->b_data;
 206         if (ondisk->vol_signature != HAMMER_FSBUF_VOLUME) {
 207                 kprintf("hammer_mount: volume %s has an invalid header\n",
 208                         volume->vol_name);
 209                 error = EFTYPE;
 210                 goto late_failure;
 211         }
 212         volume->vol_no = ondisk->vol_no;
 213         volume->buffer_base = ondisk->vol_buf_beg;
 214         volume->vol_flags = ondisk->vol_flags;
 215         volume->nblocks = ondisk->vol_nblocks;
 216         volume->maxbuf_off = HAMMER_ENCODE_RAW_BUFFER(volume->vol_no,
 217                                     ondisk->vol_buf_end - ondisk->vol_buf_beg);
 218         volume->maxraw_off = ondisk->vol_buf_end;
 219
 220         if (RB_EMPTY(&hmp->rb_vols_root)) {
 221                 hmp->fsid = ondisk->vol_fsid;
 222         } else if (bcmp(&hmp->fsid, &ondisk->vol_fsid, sizeof(uuid_t))) {
 223                 kprintf("hammer_mount: volume %s's fsid does not match "
 224                         "other volumes\n", volume->vol_name);
 225                 error = EFTYPE;
 226                 goto late_failure;
 227         }
 228
 229         /*
 230          * Insert the volume structure into the red-black tree.
 231          */
 232         if (RB_INSERT(hammer_vol_rb_tree, &hmp->rb_vols_root, volume)) {
 233                 kprintf("hammer_mount: volume %s has a duplicate vol_no %d\n",
 234                         volume->vol_name, volume->vol_no);
 235                 error = EEXIST;
 236         }
 237
 238         /*
 239          * Set the root volume .  HAMMER special cases rootvol the structure.
 240          * We do not hold a ref because this would prevent related I/O
 241          * from being flushed.
 242          */
 243         if (error == 0 && ondisk->vol_rootvol == ondisk->vol_no) {
 244                 hmp->rootvol = volume;
 245                 if (bp) {
 246                         brelse(bp);
 247                         bp = NULL;
 248                 }
 249                 hmp->fsid_udev = dev2udev(vn_todev(volume->devvp));
 250                 hmp->mp->mnt_stat.f_blocks += ondisk->vol0_stat_bigblocks *
 251                         (HAMMER_LARGEBLOCK_SIZE / HAMMER_BUFSIZE);
 252                 hmp->mp->mnt_vstat.f_blocks += ondisk->vol0_stat_bigblocks *
 253                         (HAMMER_LARGEBLOCK_SIZE / HAMMER_BUFSIZE);
 254         }
 255 late_failure:
 256         if (bp)
 257                 brelse(bp);
 258         if (error) {
 259                 /*vinvalbuf(volume->devvp, V_SAVE, 0, 0);*/
 260                 if (setmp)
 261                         volume->devvp->v_rdev->si_mountpoint = NULL;
 262                 VOP_CLOSE(volume->devvp, ronly ? FREAD : FREAD|FWRITE);
 263                 hammer_free_volume(volume);
 264         }
 265         return (error);
 266 }
 267
 268 /*
 269  * This is called for each volume when updating the mount point from
 270  * read-write to read-only or vise-versa.
 271  */
 272 int
 273 hammer_adjust_volume_mode(hammer_volume_t volume, void *data __unused)
 274 {
 275         if (volume->devvp) {
 276                 vn_lock(volume->devvp, LK_EXCLUSIVE | LK_RETRY);
 277                 if (volume->io.hmp->ronly) {
 278                         /* do not call vinvalbuf */
 279                         VOP_OPEN(volume->devvp, FREAD, FSCRED, NULL);
 280                         VOP_CLOSE(volume->devvp, FREAD|FWRITE);
 281                 } else {
 282                         /* do not call vinvalbuf */
 283                         VOP_OPEN(volume->devvp, FREAD|FWRITE, FSCRED, NULL);
 284                         VOP_CLOSE(volume->devvp, FREAD);
 285                 }
 286                 vn_unlock(volume->devvp);
 287         }
 288         return(0);
 289 }
 290
 291 /*
 292  * Unload and free a HAMMER volume.  Must return >= 0 to continue scan
 293  * so returns -1 on failure.
 294  */
 295 int
 296 hammer_unload_volume(hammer_volume_t volume, void *data __unused)
 297 {
 298         struct hammer_mount *hmp = volume->io.hmp;
 299         int ronly = ((hmp->mp->mnt_flag & MNT_RDONLY) ? 1 : 0);
 300
 301         /*
 302          * Clean up the root volume pointer, which is held unlocked in hmp.
 303          */
 304         if (hmp->rootvol == volume)
 305                 hmp->rootvol = NULL;
 306
 307         /*
 308          * Release our buffer and flush anything left in the buffer cache.
 309          */
 310         volume->io.waitdep = 1;
 311         hammer_io_release(&volume->io, 1);
 312         hammer_io_clear_modlist(&volume->io);
 313
 314         /*
 315          * There should be no references on the volume, no clusters, and
 316          * no super-clusters.
 317          */
 318         KKASSERT(volume->io.lock.refs == 0);
 319
 320         volume->ondisk = NULL;
 321         if (volume->devvp) {
 322                 if (volume->devvp->v_rdev &&
 323                     volume->devvp->v_rdev->si_mountpoint == hmp->mp
 324                 ) {
 325                         volume->devvp->v_rdev->si_mountpoint = NULL;
 326                 }
 327                 if (ronly) {
 328                         vinvalbuf(volume->devvp, 0, 0, 0);
 329                         VOP_CLOSE(volume->devvp, FREAD);
 330                 } else {
 331                         vinvalbuf(volume->devvp, V_SAVE, 0, 0);
 332                         VOP_CLOSE(volume->devvp, FREAD|FWRITE);
 333                 }
 334         }
 335
 336         /*
 337          * Destroy the structure
 338          */
 339         RB_REMOVE(hammer_vol_rb_tree, &hmp->rb_vols_root, volume);
 340         hammer_free_volume(volume);
 341         return(0);
 342 }
 343
 344 static
 345 void
 346 hammer_free_volume(hammer_volume_t volume)
 347 {
 348         if (volume->vol_name) {
 349                 kfree(volume->vol_name, M_HAMMER);
 350                 volume->vol_name = NULL;
 351         }
 352         if (volume->devvp) {
 353                 vrele(volume->devvp);
 354                 volume->devvp = NULL;
 355         }
 356         --hammer_count_volumes;
 357         kfree(volume, M_HAMMER);
 358 }
 359
 360 /*
 361  * Get a HAMMER volume.  The volume must already exist.
 362  */
 363 hammer_volume_t
 364 hammer_get_volume(struct hammer_mount *hmp, int32_t vol_no, int *errorp)
 365 {
 366         struct hammer_volume *volume;
 367
 368         /*
 369          * Locate the volume structure
 370          */
 371         volume = RB_LOOKUP(hammer_vol_rb_tree, &hmp->rb_vols_root, vol_no);
 372         if (volume == NULL) {
 373                 *errorp = ENOENT;
 374                 return(NULL);
 375         }
 376         hammer_ref(&volume->io.lock);
 377
 378         /*
 379          * Deal with on-disk info
 380          */
 381         if (volume->ondisk == NULL || volume->io.loading) {
 382                 *errorp = hammer_load_volume(volume);
 383                 if (*errorp) {
 384                         hammer_rel_volume(volume, 1);
 385                         volume = NULL;
 386                 }
 387         } else {
 388                 *errorp = 0;
 389         }
 390         return(volume);
 391 }
 392
 393 int
 394 hammer_ref_volume(hammer_volume_t volume)
 395 {
 396         int error;
 397
 398         hammer_ref(&volume->io.lock);
 399
 400         /*
 401          * Deal with on-disk info
 402          */
 403         if (volume->ondisk == NULL || volume->io.loading) {
 404                 error = hammer_load_volume(volume);
 405                 if (error)
 406                         hammer_rel_volume(volume, 1);
 407         } else {
 408                 error = 0;
 409         }
 410         return (error);
 411 }
 412
 413 hammer_volume_t
 414 hammer_get_root_volume(struct hammer_mount *hmp, int *errorp)
 415 {
 416         hammer_volume_t volume;
 417
 418         volume = hmp->rootvol;
 419         KKASSERT(volume != NULL);
 420         hammer_ref(&volume->io.lock);
 421
 422         /*
 423          * Deal with on-disk info
 424          */
 425         if (volume->ondisk == NULL || volume->io.loading) {
 426                 *errorp = hammer_load_volume(volume);
 427                 if (*errorp) {
 428                         hammer_rel_volume(volume, 1);
 429                         volume = NULL;
 430                 }
 431         } else {
 432                 *errorp = 0;
 433         }
 434         return (volume);
 435 }
 436
 437 /*
 438  * Load a volume's on-disk information.  The volume must be referenced and
 439  * not locked.  We temporarily acquire an exclusive lock to interlock
 440  * against releases or multiple get's.
 441  */
 442 static int
 443 hammer_load_volume(hammer_volume_t volume)
 444 {
 445         int error;
 446
 447         ++volume->io.loading;
 448         hammer_lock_ex(&volume->io.lock);
 449
 450         if (volume->ondisk == NULL) {
 451                 error = hammer_io_read(volume->devvp, &volume->io,
 452                                        volume->maxraw_off);
 453                 if (error == 0)
 454                         volume->ondisk = (void *)volume->io.bp->b_data;
 455         } else {
 456                 error = 0;
 457         }
 458         --volume->io.loading;
 459         hammer_unlock(&volume->io.lock);
 460         return(error);
 461 }
 462
 463 /*
 464  * Release a volume.  Call hammer_io_release on the last reference.  We have
 465  * to acquire an exclusive lock to interlock against volume->ondisk tests
 466  * in hammer_load_volume(), and hammer_io_release() also expects an exclusive
 467  * lock to be held.
 468  *
 469  * Volumes are not unloaded from memory during normal operation.
 470  */
 471 void
 472 hammer_rel_volume(hammer_volume_t volume, int flush)
 473 {
 474         crit_enter();
 475         if (volume->io.lock.refs == 1) {
 476                 ++volume->io.loading;
 477                 hammer_lock_ex(&volume->io.lock);
 478                 if (volume->io.lock.refs == 1) {
 479                         volume->ondisk = NULL;
 480                         hammer_io_release(&volume->io, flush);
 481                 }
 482                 --volume->io.loading;
 483                 hammer_unlock(&volume->io.lock);
 484         }
 485         hammer_unref(&volume->io.lock);
 486         crit_exit();
 487 }
 488
 489 /************************************************************************
 490  *                              BUFFERS                                 *
 491  ************************************************************************
 492  *
 493  * Manage buffers.  Currently all blockmap-backed zones are translated
 494  * to zone-2 buffer offsets.
 495  */
 496 hammer_buffer_t
 497 hammer_get_buffer(hammer_mount_t hmp, hammer_off_t buf_offset,
 498                   int isnew, int *errorp)
 499 {
 500         hammer_buffer_t buffer;
 501         hammer_volume_t volume;
 502         hammer_off_t    zone2_offset;
 503         hammer_io_type_t iotype;
 504         int vol_no;
 505         int zone;
 506
 507         buf_offset &= ~HAMMER_BUFMASK64;
 508 again:
 509         /*
 510          * Shortcut if the buffer is already cached
 511          */
 512         buffer = RB_LOOKUP(hammer_buf_rb_tree, &hmp->rb_bufs_root, buf_offset);
 513         if (buffer) {
 514                 if (buffer->io.lock.refs == 0)
 515                         ++hammer_count_refedbufs;
 516                 hammer_ref(&buffer->io.lock);
 517
 518                 /*
 519                  * Onced refed the ondisk field will not be cleared by
 520                  * any other action.
 521                  */
 522                 if (buffer->ondisk && buffer->io.loading == 0) {
 523                         *errorp = 0;
 524                         return(buffer);
 525                 }
 526
 527                 /*
 528                  * The buffer is no longer loose if it has a ref, and
 529                  * cannot become loose once it gains a ref.  Loose
 530                  * buffers will never be in a modified state.  This should
 531                  * only occur on the 0->1 transition of refs.
 532                  *
 533                  * lose_list can be modified via a biodone() interrupt.
 534                  */
 535                 if (buffer->io.mod_list == &hmp->lose_list) {
 536                         crit_enter();   /* biodone race against list */
 537                         TAILQ_REMOVE(buffer->io.mod_list, &buffer->io,
 538                                      mod_entry);
 539                         crit_exit();
 540                         buffer->io.mod_list = NULL;
 541                         KKASSERT(buffer->io.modified == 0);
 542                 }
 543                 goto found;
 544         }
 545
 546         /*
 547          * What is the buffer class?
 548          */
 549         zone = HAMMER_ZONE_DECODE(buf_offset);
 550
 551         switch(zone) {
 552         case HAMMER_ZONE_LARGE_DATA_INDEX:
 553         case HAMMER_ZONE_SMALL_DATA_INDEX:
 554         case HAMMER_ZONE_META_INDEX:  /* meta-data isn't a meta-buffer */
 555                 iotype = HAMMER_STRUCTURE_DATA_BUFFER;
 556                 break;
 557         case HAMMER_ZONE_UNDO_INDEX:
 558                 iotype = HAMMER_STRUCTURE_UNDO_BUFFER;
 559                 break;
 560         default:
 561                 iotype = HAMMER_STRUCTURE_META_BUFFER;
 562                 break;
 563         }
 564
 565         /*
 566          * Handle blockmap offset translations
 567          */
 568         if (zone >= HAMMER_ZONE_BTREE_INDEX) {
 569                 zone2_offset = hammer_blockmap_lookup(hmp, buf_offset, errorp);
 570         } else if (zone == HAMMER_ZONE_UNDO_INDEX) {
 571                 zone2_offset = hammer_undo_lookup(hmp, buf_offset, errorp);
 572         } else {
 573                 KKASSERT(zone == HAMMER_ZONE_RAW_BUFFER_INDEX);
 574                 zone2_offset = buf_offset;
 575                 *errorp = 0;
 576         }
 577         if (*errorp)
 578                 return(NULL);
 579
 580         /*
 581          * NOTE: zone2_offset and maxbuf_off are both full zone-2 offset
 582          * specifications.
 583          */
 584         KKASSERT((zone2_offset & HAMMER_OFF_ZONE_MASK) ==
 585                  HAMMER_ZONE_RAW_BUFFER);
 586         vol_no = HAMMER_VOL_DECODE(zone2_offset);
 587         volume = hammer_get_volume(hmp, vol_no, errorp);
 588         if (volume == NULL)
 589                 return(NULL);
 590
 591         KKASSERT(zone2_offset < volume->maxbuf_off);
 592
 593         /*
 594          * Allocate a new buffer structure.  We will check for races later.
 595          */
 596         ++hammer_count_buffers;
 597         buffer = kmalloc(sizeof(*buffer), M_HAMMER, M_WAITOK|M_ZERO);
 598         buffer->zone2_offset = zone2_offset;
 599         buffer->zoneX_offset = buf_offset;
 600         buffer->volume = volume;
 601
 602         hammer_io_init(&buffer->io, hmp, iotype);
 603         buffer->io.offset = volume->ondisk->vol_buf_beg +
 604                             (zone2_offset & HAMMER_OFF_SHORT_MASK);
 605         TAILQ_INIT(&buffer->clist);
 606         hammer_ref(&buffer->io.lock);
 607
 608         /*
 609          * Insert the buffer into the RB tree and handle late collisions.
 610          */
 611         if (RB_INSERT(hammer_buf_rb_tree, &hmp->rb_bufs_root, buffer)) {
 612                 hammer_unref(&buffer->io.lock);
 613                 --hammer_count_buffers;
 614                 kfree(buffer, M_HAMMER);
 615                 goto again;
 616         }
 617         ++hammer_count_refedbufs;
 618 found:
 619
 620         /*
 621          * Deal with on-disk info and loading races.
 622          */
 623         if (buffer->ondisk == NULL || buffer->io.loading) {
 624                 *errorp = hammer_load_buffer(buffer, isnew);
 625                 if (*errorp) {
 626                         hammer_rel_buffer(buffer, 1);
 627                         buffer = NULL;
 628                 }
 629         } else {
 630                 *errorp = 0;
 631         }
 632         return(buffer);
 633 }
 634
 635 /*
 636  * Destroy all buffers covering the specified zoneX offset range.  This
 637  * is called when the related blockmap layer2 entry is freed or when
 638  * a direct write bypasses our buffer/buffer-cache subsystem.
 639  *
 640  * The buffers may be referenced by the caller itself.  Setting reclaim
 641  * will cause the buffer to be destroyed when it's ref count reaches zero.
 642  */
 643 void
 644 hammer_del_buffers(hammer_mount_t hmp, hammer_off_t base_offset,
 645                    hammer_off_t zone2_offset, int bytes)
 646 {
 647         hammer_buffer_t buffer;
 648         hammer_volume_t volume;
 649         int vol_no;
 650         int error;
 651
 652         vol_no = HAMMER_VOL_DECODE(zone2_offset);
 653         volume = hammer_get_volume(hmp, vol_no, &error);
 654         KKASSERT(error == 0);
 655
 656         while (bytes > 0) {
 657                 buffer = RB_LOOKUP(hammer_buf_rb_tree, &hmp->rb_bufs_root,
 658                                    base_offset);
 659                 if (buffer) {
 660                         KKASSERT(buffer->zone2_offset == zone2_offset);
 661                         hammer_io_clear_modify(&buffer->io);
 662                         buffer->io.reclaim = 1;
 663                         KKASSERT(buffer->volume == volume);
 664                         if (buffer->io.lock.refs == 0)
 665                                 hammer_unload_buffer(buffer, NULL);
 666                 } else {
 667                         hammer_io_inval(volume, zone2_offset);
 668                 }
 669                 base_offset += HAMMER_BUFSIZE;
 670                 zone2_offset += HAMMER_BUFSIZE;
 671                 bytes -= HAMMER_BUFSIZE;
 672         }
 673         hammer_rel_volume(volume, 0);
 674 }
 675
 676 static int
 677 hammer_load_buffer(hammer_buffer_t buffer, int isnew)
 678 {
 679         hammer_volume_t volume;
 680         int error;
 681
 682         /*
 683          * Load the buffer's on-disk info
 684          */
 685         volume = buffer->volume;
 686         ++buffer->io.loading;
 687         hammer_lock_ex(&buffer->io.lock);
 688
 689         if (hammer_debug_io & 0x0001) {
 690                 kprintf("load_buffer %016llx %016llx isnew=%d od=%p\n",
 691                         buffer->zoneX_offset, buffer->zone2_offset, isnew,
 692                         buffer->ondisk);
 693         }
 694
 695         if (buffer->ondisk == NULL) {
 696                 if (isnew) {
 697                         error = hammer_io_new(volume->devvp, &buffer->io);
 698                 } else {
 699                         error = hammer_io_read(volume->devvp, &buffer->io,
 700                                                volume->maxraw_off);
 701                 }
 702                 if (error == 0)
 703                         buffer->ondisk = (void *)buffer->io.bp->b_data;
 704         } else if (isnew) {
 705                 error = hammer_io_new(volume->devvp, &buffer->io);
 706         } else {
 707                 error = 0;
 708         }
 709         --buffer->io.loading;
 710         hammer_unlock(&buffer->io.lock);
 711         return (error);
 712 }
 713
 714 /*
 715  * NOTE: Called from RB_SCAN, must return >= 0 for scan to continue.
 716  */
 717 int
 718 hammer_unload_buffer(hammer_buffer_t buffer, void *data __unused)
 719 {
 720         ++hammer_count_refedbufs;
 721         hammer_ref(&buffer->io.lock);
 722         hammer_flush_buffer_nodes(buffer);
 723         KKASSERT(buffer->io.lock.refs == 1);
 724         hammer_rel_buffer(buffer, 2);
 725         return(0);
 726 }
 727
 728 /*
 729  * Reference a buffer that is either already referenced or via a specially
 730  * handled pointer (aka cursor->buffer).
 731  */
 732 int
 733 hammer_ref_buffer(hammer_buffer_t buffer)
 734 {
 735         int error;
 736
 737         if (buffer->io.lock.refs == 0)
 738                 ++hammer_count_refedbufs;
 739         hammer_ref(&buffer->io.lock);
 740
 741         /*
 742          * At this point a biodone() will not touch the buffer other then
 743          * incidental bits.  However, lose_list can be modified via
 744          * a biodone() interrupt.
 745          *
 746          * No longer loose
 747          */
 748         if (buffer->io.mod_list == &buffer->io.hmp->lose_list) {
 749                 crit_enter();
 750                 TAILQ_REMOVE(buffer->io.mod_list, &buffer->io, mod_entry);
 751                 buffer->io.mod_list = NULL;
 752                 crit_exit();
 753         }
 754
 755         if (buffer->ondisk == NULL || buffer->io.loading) {
 756                 error = hammer_load_buffer(buffer, 0);
 757                 if (error) {
 758                         hammer_rel_buffer(buffer, 1);
 759                         /*
 760                          * NOTE: buffer pointer can become stale after
 761                          * the above release.
 762                          */
 763                 }
 764         } else {
 765                 error = 0;
 766         }
 767         return(error);
 768 }
 769
 770 /*
 771  * Release a buffer.  We have to deal with several places where
 772  * another thread can ref the buffer.
 773  *
 774  * Only destroy the structure itself if the related buffer cache buffer
 775  * was disassociated from it.  This ties the management of the structure
 776  * to the buffer cache subsystem.  buffer->ondisk determines whether the
 777  * embedded io is referenced or not.
 778  */
 779 void
 780 hammer_rel_buffer(hammer_buffer_t buffer, int flush)
 781 {
 782         hammer_volume_t volume;
 783         int freeme = 0;
 784
 785         crit_enter();
 786         if (buffer->io.lock.refs == 1) {
 787                 ++buffer->io.loading;   /* force interlock check */
 788                 hammer_lock_ex(&buffer->io.lock);
 789                 if (buffer->io.lock.refs == 1) {
 790                         hammer_io_release(&buffer->io, flush);
 791
 792                         if (buffer->io.lock.refs == 1)
 793                                 --hammer_count_refedbufs;
 794
 795                         if (buffer->io.bp == NULL &&
 796                             buffer->io.lock.refs == 1) {
 797                                 /*
 798                                  * Final cleanup
 799                                  *
 800                                  * NOTE: It is impossible for any associated
 801                                  * B-Tree nodes to have refs if the buffer
 802                                  * has no additional refs.
 803                                  */
 804                                 RB_REMOVE(hammer_buf_rb_tree,
 805                                           &buffer->io.hmp->rb_bufs_root,
 806                                           buffer);
 807                                 volume = buffer->volume;
 808                                 buffer->volume = NULL; /* sanity */
 809                                 hammer_rel_volume(volume, 0);
 810                                 hammer_io_clear_modlist(&buffer->io);
 811                                 hammer_flush_buffer_nodes(buffer);
 812                                 KKASSERT(TAILQ_EMPTY(&buffer->clist));
 813                                 freeme = 1;
 814                         }
 815                 }
 816                 --buffer->io.loading;
 817                 hammer_unlock(&buffer->io.lock);
 818         }
 819         hammer_unref(&buffer->io.lock);
 820         crit_exit();
 821         if (freeme) {
 822                 --hammer_count_buffers;
 823                 kfree(buffer, M_HAMMER);
 824         }
 825 }
 826
 827 /*
 828  * Access the filesystem buffer containing the specified hammer offset.
 829  * buf_offset is a conglomeration of the volume number and vol_buf_beg
 830  * relative buffer offset.  It must also have bit 55 set to be valid.
 831  * (see hammer_off_t in hammer_disk.h).
 832  *
 833  * Any prior buffer in *bufferp will be released and replaced by the
 834  * requested buffer.
 835  */
 836 void *
 837 hammer_bread(hammer_mount_t hmp, hammer_off_t buf_offset, int *errorp,
 838              struct hammer_buffer **bufferp)
 839 {
 840         hammer_buffer_t buffer;
 841         int32_t xoff = (int32_t)buf_offset & HAMMER_BUFMASK;
 842
 843         buf_offset &= ~HAMMER_BUFMASK64;
 844         KKASSERT((buf_offset & HAMMER_OFF_ZONE_MASK) != 0);
 845
 846         buffer = *bufferp;
 847         if (buffer == NULL || (buffer->zone2_offset != buf_offset &&
 848                                buffer->zoneX_offset != buf_offset)) {
 849                 if (buffer)
 850                         hammer_rel_buffer(buffer, 0);
 851                 buffer = hammer_get_buffer(hmp, buf_offset, 0, errorp);
 852                 *bufferp = buffer;
 853         } else {
 854                 *errorp = 0;
 855         }
 856
 857         /*
 858          * Return a pointer to the buffer data.
 859          */
 860         if (buffer == NULL)
 861                 return(NULL);
 862         else
 863                 return((char *)buffer->ondisk + xoff);
 864 }
 865
 866 /*
 867  * Access the filesystem buffer containing the specified hammer offset.
 868  * No disk read operation occurs.  The result buffer may contain garbage.
 869  *
 870  * Any prior buffer in *bufferp will be released and replaced by the
 871  * requested buffer.
 872  *
 873  * This function marks the buffer dirty but does not increment its
 874  * modify_refs count.
 875  */
 876 void *
 877 hammer_bnew(hammer_mount_t hmp, hammer_off_t buf_offset, int *errorp,
 878              struct hammer_buffer **bufferp)
 879 {
 880         hammer_buffer_t buffer;
 881         int32_t xoff = (int32_t)buf_offset & HAMMER_BUFMASK;
 882
 883         buf_offset &= ~HAMMER_BUFMASK64;
 884
 885         buffer = *bufferp;
 886         if (buffer == NULL || (buffer->zone2_offset != buf_offset &&
 887                                buffer->zoneX_offset != buf_offset)) {
 888                 if (buffer)
 889                         hammer_rel_buffer(buffer, 0);
 890                 buffer = hammer_get_buffer(hmp, buf_offset, 1, errorp);
 891                 *bufferp = buffer;
 892         } else {
 893                 *errorp = 0;
 894         }
 895
 896         /*
 897          * Return a pointer to the buffer data.
 898          */
 899         if (buffer == NULL)
 900                 return(NULL);
 901         else
 902                 return((char *)buffer->ondisk + xoff);
 903 }
 904
 905 /************************************************************************
 906  *                              NODES                                   *
 907  ************************************************************************
 908  *
 909  * Manage B-Tree nodes.  B-Tree nodes represent the primary indexing
 910  * method used by the HAMMER filesystem.
 911  *
 912  * Unlike other HAMMER structures, a hammer_node can be PASSIVELY
 913  * associated with its buffer, and will only referenced the buffer while
 914  * the node itself is referenced.
 915  *
 916  * A hammer_node can also be passively associated with other HAMMER
 917  * structures, such as inodes, while retaining 0 references.  These
 918  * associations can be cleared backwards using a pointer-to-pointer in
 919  * the hammer_node.
 920  *
 921  * This allows the HAMMER implementation to cache hammer_nodes long-term
 922  * and short-cut a great deal of the infrastructure's complexity.  In
 923  * most cases a cached node can be reacquired without having to dip into
 924  * either the buffer or cluster management code.
 925  *
 926  * The caller must pass a referenced cluster on call and will retain
 927  * ownership of the reference on return.  The node will acquire its own
 928  * additional references, if necessary.
 929  */
 930 hammer_node_t
 931 hammer_get_node(hammer_mount_t hmp, hammer_off_t node_offset,
 932                 int isnew, int *errorp)
 933 {
 934         hammer_node_t node;
 935
 936         KKASSERT((node_offset & HAMMER_OFF_ZONE_MASK) == HAMMER_ZONE_BTREE);
 937
 938         /*
 939          * Locate the structure, allocating one if necessary.
 940          */
 941 again:
 942         node = RB_LOOKUP(hammer_nod_rb_tree, &hmp->rb_nods_root, node_offset);
 943         if (node == NULL) {
 944                 ++hammer_count_nodes;
 945                 node = kmalloc(sizeof(*node), M_HAMMER, M_WAITOK|M_ZERO);
 946                 node->node_offset = node_offset;
 947                 node->hmp = hmp;
 948                 TAILQ_INIT(&node->cache_list);
 949                 if (RB_INSERT(hammer_nod_rb_tree, &hmp->rb_nods_root, node)) {
 950                         --hammer_count_nodes;
 951                         kfree(node, M_HAMMER);
 952                         goto again;
 953                 }
 954         }
 955         hammer_ref(&node->lock);
 956         if (node->ondisk)
 957                 *errorp = 0;
 958         else
 959                 *errorp = hammer_load_node(node, isnew);
 960         if (*errorp) {
 961                 hammer_rel_node(node);
 962                 node = NULL;
 963         }
 964         return(node);
 965 }
 966
 967 /*
 968  * Reference an already-referenced node.
 969  */
 970 void
 971 hammer_ref_node(hammer_node_t node)
 972 {
 973         KKASSERT(node->lock.refs > 0 && node->ondisk != NULL);
 974         hammer_ref(&node->lock);
 975 }
 976
 977 /*
 978  * Load a node's on-disk data reference.
 979  */
 980 static int
 981 hammer_load_node(hammer_node_t node, int isnew)
 982 {
 983         hammer_buffer_t buffer;
 984         hammer_off_t buf_offset;
 985         int error;
 986
 987         error = 0;
 988         ++node->loading;
 989         hammer_lock_ex(&node->lock);
 990         if (node->ondisk == NULL) {
 991                 /*
 992                  * This is a little confusing but the jist is that
 993                  * node->buffer determines whether the node is on
 994                  * the buffer's clist and node->ondisk determines
 995                  * whether the buffer is referenced.
 996                  *
 997                  * We could be racing a buffer release, in which case
 998                  * node->buffer may become NULL while we are blocked
 999                  * referencing the buffer.
1000                  */
1001                 if ((buffer = node->buffer) != NULL) {
1002                         error = hammer_ref_buffer(buffer);
1003                         if (error == 0 && node->buffer == NULL) {
1004                                 TAILQ_INSERT_TAIL(&buffer->clist,
1005                                                   node, entry);
1006                                 node->buffer = buffer;
1007                         }
1008                 } else {
1009                         buf_offset = node->node_offset & ~HAMMER_BUFMASK64;
1010                         buffer = hammer_get_buffer(node->hmp, buf_offset,
1011                                                    0, &error);
1012                         if (buffer) {
1013                                 KKASSERT(error == 0);
1014                                 TAILQ_INSERT_TAIL(&buffer->clist,
1015                                                   node, entry);
1016                                 node->buffer = buffer;
1017                         }
1018                 }
1019                 if (error)
1020                         goto failed;
1021                 node->ondisk = (void *)((char *)buffer->ondisk +
1022                                         (node->node_offset & HAMMER_BUFMASK));
1023                 if (isnew == 0 &&
1024                     (node->flags & HAMMER_NODE_CRCGOOD) == 0) {
1025                         if (hammer_crc_test_btree(node->ondisk) == 0)
1026                                 Debugger("CRC FAILED: B-TREE NODE");
1027                         node->flags |= HAMMER_NODE_CRCGOOD;
1028                 }
1029         }
1030 failed:
1031         --node->loading;
1032         hammer_unlock(&node->lock);
1033         return (error);
1034 }
1035
1036 /*
1037  * Safely reference a node, interlock against flushes via the IO subsystem.
1038  */
1039 hammer_node_t
1040 hammer_ref_node_safe(struct hammer_mount *hmp, hammer_node_cache_t cache,
1041                      int *errorp)
1042 {
1043         hammer_node_t node;
1044
1045         node = cache->node;
1046         if (node != NULL) {
1047                 hammer_ref(&node->lock);
1048                 if (node->ondisk)
1049                         *errorp = 0;
1050                 else
1051                         *errorp = hammer_load_node(node, 0);
1052                 if (*errorp) {
1053                         hammer_rel_node(node);
1054                         node = NULL;
1055                 }
1056         } else {
1057                 *errorp = ENOENT;
1058         }
1059         return(node);
1060 }
1061
1062 /*
1063  * Release a hammer_node.  On the last release the node dereferences
1064  * its underlying buffer and may or may not be destroyed.
1065  */
1066 void
1067 hammer_rel_node(hammer_node_t node)
1068 {
1069         hammer_buffer_t buffer;
1070
1071         /*
1072          * If this isn't the last ref just decrement the ref count and
1073          * return.
1074          */
1075         if (node->lock.refs > 1) {
1076                 hammer_unref(&node->lock);
1077                 return;
1078         }
1079
1080         /*
1081          * If there is no ondisk info or no buffer the node failed to load,
1082          * remove the last reference and destroy the node.
1083          */
1084         if (node->ondisk == NULL) {
1085                 hammer_unref(&node->lock);
1086                 hammer_flush_node(node);
1087                 /* node is stale now */
1088                 return;
1089         }
1090
1091         /*
1092          * Do not disassociate the node from the buffer if it represents
1093          * a modified B-Tree node that still needs its crc to be generated.
1094          */
1095         if (node->flags & HAMMER_NODE_NEEDSCRC)
1096                 return;
1097
1098         /*
1099          * Do final cleanups and then either destroy the node and leave it
1100          * passively cached.  The buffer reference is removed regardless.
1101          */
1102         buffer = node->buffer;
1103         node->ondisk = NULL;
1104
1105         if ((node->flags & HAMMER_NODE_FLUSH) == 0) {
1106                 hammer_unref(&node->lock);
1107                 hammer_rel_buffer(buffer, 0);
1108                 return;
1109         }
1110
1111         /*
1112          * Destroy the node.
1113          */
1114         hammer_unref(&node->lock);
1115         hammer_flush_node(node);
1116         /* node is stale */
1117         hammer_rel_buffer(buffer, 0);
1118 }
1119
1120 /*
1121  * Free space on-media associated with a B-Tree node.
1122  */
1123 void
1124 hammer_delete_node(hammer_transaction_t trans, hammer_node_t node)
1125 {
1126         KKASSERT((node->flags & HAMMER_NODE_DELETED) == 0);
1127         node->flags |= HAMMER_NODE_DELETED;
1128         hammer_blockmap_free(trans, node->node_offset, sizeof(*node->ondisk));
1129 }
1130
1131 /*
1132  * Passively cache a referenced hammer_node.  The caller may release
1133  * the node on return.
1134  */
1135 void
1136 hammer_cache_node(hammer_node_cache_t cache, hammer_node_t node)
1137 {
1138         /*
1139          * If the node is being deleted, don't cache it!
1140          */
1141         if (node->flags & HAMMER_NODE_DELETED)
1142                 return;
1143         if (cache->node == node)
1144                 return;
1145         while (cache->node)
1146                 hammer_uncache_node(cache);
1147         if (node->flags & HAMMER_NODE_DELETED)
1148                 return;
1149         cache->node = node;
1150         TAILQ_INSERT_TAIL(&node->cache_list, cache, entry);
1151 }
1152
1153 void
1154 hammer_uncache_node(hammer_node_cache_t cache)
1155 {
1156         hammer_node_t node;
1157
1158         if ((node = cache->node) != NULL) {
1159                 TAILQ_REMOVE(&node->cache_list, cache, entry);
1160                 cache->node = NULL;
1161                 if (TAILQ_EMPTY(&node->cache_list))
1162                         hammer_flush_node(node);
1163         }
1164 }
1165
1166 /*
1167  * Remove a node's cache references and destroy the node if it has no
1168  * other references or backing store.
1169  */
1170 void
1171 hammer_flush_node(hammer_node_t node)
1172 {
1173         hammer_node_cache_t cache;
1174         hammer_buffer_t buffer;
1175
1176         while ((cache = TAILQ_FIRST(&node->cache_list)) != NULL) {
1177                 TAILQ_REMOVE(&node->cache_list, cache, entry);
1178                 cache->node = NULL;
1179         }
1180         if (node->lock.refs == 0 && node->ondisk == NULL) {
1181                 KKASSERT((node->flags & HAMMER_NODE_NEEDSCRC) == 0);
1182                 RB_REMOVE(hammer_nod_rb_tree, &node->hmp->rb_nods_root, node);
1183                 if ((buffer = node->buffer) != NULL) {
1184                         node->buffer = NULL;
1185                         TAILQ_REMOVE(&buffer->clist, node, entry);
1186                         /* buffer is unreferenced because ondisk is NULL */
1187                 }
1188                 --hammer_count_nodes;
1189                 kfree(node, M_HAMMER);
1190         }
1191 }
1192
1193 /*
1194  * Flush passively cached B-Tree nodes associated with this buffer.
1195  * This is only called when the buffer is about to be destroyed, so
1196  * none of the nodes should have any references.  The buffer is locked.
1197  *
1198  * We may be interlocked with the buffer.
1199  */
1200 void
1201 hammer_flush_buffer_nodes(hammer_buffer_t buffer)
1202 {
1203         hammer_node_t node;
1204
1205         while ((node = TAILQ_FIRST(&buffer->clist)) != NULL) {
1206                 KKASSERT(node->ondisk == NULL);
1207                 KKASSERT((node->flags & HAMMER_NODE_NEEDSCRC) == 0);
1208
1209                 if (node->lock.refs == 0) {
1210                         hammer_ref(&node->lock);
1211                         node->flags |= HAMMER_NODE_FLUSH;
1212                         hammer_rel_node(node);
1213                 } else {
1214                         KKASSERT(node->loading != 0);
1215                         KKASSERT(node->buffer != NULL);
1216                         buffer = node->buffer;
1217                         node->buffer = NULL;
1218                         TAILQ_REMOVE(&buffer->clist, node, entry);
1219                         /* buffer is unreferenced because ondisk is NULL */
1220                 }
1221         }
1222 }
1223
1224
1225 /************************************************************************
1226  *                              ALLOCATORS                              *
1227  ************************************************************************/
1228
1229 /*
1230  * Allocate a B-Tree node.
1231  */
1232 hammer_node_t
1233 hammer_alloc_btree(hammer_transaction_t trans, int *errorp)
1234 {
1235         hammer_buffer_t buffer = NULL;
1236         hammer_node_t node = NULL;
1237         hammer_off_t node_offset;
1238
1239         node_offset = hammer_blockmap_alloc(trans, HAMMER_ZONE_BTREE_INDEX,
1240                                             sizeof(struct hammer_node_ondisk),
1241                                             errorp);
1242         if (*errorp == 0) {
1243                 node = hammer_get_node(trans->hmp, node_offset, 1, errorp);
1244                 hammer_modify_node_noundo(trans, node);
1245                 bzero(node->ondisk, sizeof(*node->ondisk));
1246                 hammer_modify_node_done(node);
1247         }
1248         if (buffer)
1249                 hammer_rel_buffer(buffer, 0);
1250         return(node);
1251 }
1252
1253 /*
1254  * Allocate data.  If the address of a data buffer is supplied then
1255  * any prior non-NULL *data_bufferp will be released and *data_bufferp
1256  * will be set to the related buffer.  The caller must release it when
1257  * finally done.  The initial *data_bufferp should be set to NULL by
1258  * the caller.
1259  *
1260  * The caller is responsible for making hammer_modify*() calls on the
1261  * *data_bufferp.
1262  */
1263 void *
1264 hammer_alloc_data(hammer_transaction_t trans, int32_t data_len,
1265                   u_int16_t rec_type, hammer_off_t *data_offsetp,
1266                   struct hammer_buffer **data_bufferp, int *errorp)
1267 {
1268         void *data;
1269         int zone;
1270
1271         /*
1272          * Allocate data
1273          */
1274         if (data_len) {
1275                 switch(rec_type) {
1276                 case HAMMER_RECTYPE_INODE:
1277                 case HAMMER_RECTYPE_PSEUDO_INODE:
1278                 case HAMMER_RECTYPE_DIRENTRY:
1279                 case HAMMER_RECTYPE_EXT:
1280                 case HAMMER_RECTYPE_FIX:
1281                         zone = HAMMER_ZONE_META_INDEX;
1282                         break;
1283                 case HAMMER_RECTYPE_DATA:
1284                 case HAMMER_RECTYPE_DB:
1285                         if (data_len <= HAMMER_BUFSIZE / 2)
1286                                 zone = HAMMER_ZONE_SMALL_DATA_INDEX;
1287                         else
1288                                 zone = HAMMER_ZONE_LARGE_DATA_INDEX;
1289                         break;
1290                 default:
1291                         panic("hammer_alloc_data: rec_type %04x unknown",
1292                               rec_type);
1293                         zone = 0;       /* NOT REACHED */
1294                         break;
1295                 }
1296                 *data_offsetp = hammer_blockmap_alloc(trans, zone,
1297                                                       data_len, errorp);
1298         } else {
1299                 *data_offsetp = 0;
1300         }
1301         if (*errorp == 0 && data_bufferp) {
1302                 if (data_len) {
1303                         data = hammer_bread(trans->hmp, *data_offsetp, errorp,
1304                                             data_bufferp);
1305                         KKASSERT(*errorp == 0);
1306                 } else {
1307                         data = NULL;
1308                 }
1309         } else {
1310                 data = NULL;
1311         }
1312         KKASSERT(*errorp == 0);
1313         return(data);
1314 }
1315
1316 /*
1317  * Sync dirty buffers to the media and clean-up any loose ends.
1318  */
1319 static int hammer_sync_scan1(struct mount *mp, struct vnode *vp, void *data);
1320 static int hammer_sync_scan2(struct mount *mp, struct vnode *vp, void *data);
1321
1322 int
1323 hammer_queue_inodes_flusher(hammer_mount_t hmp, int waitfor)
1324 {
1325         struct hammer_sync_info info;
1326
1327         info.error = 0;
1328         info.waitfor = waitfor;
1329         if (waitfor == MNT_WAIT) {
1330                 vmntvnodescan(hmp->mp, VMSC_GETVP|VMSC_ONEPASS,
1331                               hammer_sync_scan1, hammer_sync_scan2, &info);
1332         } else {
1333                 vmntvnodescan(hmp->mp, VMSC_GETVP|VMSC_ONEPASS|VMSC_NOWAIT,
1334                               hammer_sync_scan1, hammer_sync_scan2, &info);
1335         }
1336         return(info.error);
1337 }
1338
1339 int
1340 hammer_sync_hmp(hammer_mount_t hmp, int waitfor)
1341 {
1342         struct hammer_sync_info info;
1343
1344         info.error = 0;
1345         info.waitfor = waitfor;
1346
1347         vmntvnodescan(hmp->mp, VMSC_GETVP|VMSC_NOWAIT,
1348                       hammer_sync_scan1, hammer_sync_scan2, &info);
1349         if (waitfor == MNT_WAIT)
1350                 hammer_flusher_sync(hmp);
1351         else
1352                 hammer_flusher_async(hmp);
1353
1354         return(info.error);
1355 }
1356
1357 static int
1358 hammer_sync_scan1(struct mount *mp, struct vnode *vp, void *data)
1359 {
1360         struct hammer_inode *ip;
1361
1362         ip = VTOI(vp);
1363         if (vp->v_type == VNON || ip == NULL ||
1364             ((ip->flags & HAMMER_INODE_MODMASK) == 0 &&
1365              RB_EMPTY(&vp->v_rbdirty_tree))) {
1366                 return(-1);
1367         }
1368         return(0);
1369 }
1370
1371 static int
1372 hammer_sync_scan2(struct mount *mp, struct vnode *vp, void *data)
1373 {
1374         struct hammer_sync_info *info = data;
1375         struct hammer_inode *ip;
1376         int error;
1377
1378         ip = VTOI(vp);
1379         if (vp->v_type == VNON || vp->v_type == VBAD ||
1380             ((ip->flags & HAMMER_INODE_MODMASK) == 0 &&
1381              RB_EMPTY(&vp->v_rbdirty_tree))) {
1382                 return(0);
1383         }
1384         error = VOP_FSYNC(vp, info->waitfor);
1385         if (error)
1386                 info->error = error;
1387         return(0);
1388 }
1389