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 1.46 2008/05/18 01:48:50 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 static 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->zone2_offset < buf2->zone2_offset)
  98                 return(-1);
  99         if (buf1->zone2_offset > buf2->zone2_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, zone2_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         RB_INIT(&volume->rb_bufs_root);
 220
 221         if (RB_EMPTY(&hmp->rb_vols_root)) {
 222                 hmp->fsid = ondisk->vol_fsid;
 223         } else if (bcmp(&hmp->fsid, &ondisk->vol_fsid, sizeof(uuid_t))) {
 224                 kprintf("hammer_mount: volume %s's fsid does not match "
 225                         "other volumes\n", volume->vol_name);
 226                 error = EFTYPE;
 227                 goto late_failure;
 228         }
 229
 230         /*
 231          * Insert the volume structure into the red-black tree.
 232          */
 233         if (RB_INSERT(hammer_vol_rb_tree, &hmp->rb_vols_root, volume)) {
 234                 kprintf("hammer_mount: volume %s has a duplicate vol_no %d\n",
 235                         volume->vol_name, volume->vol_no);
 236                 error = EEXIST;
 237         }
 238
 239         /*
 240          * Set the root volume .  HAMMER special cases rootvol the structure.
 241          * We do not hold a ref because this would prevent related I/O
 242          * from being flushed.
 243          */
 244         if (error == 0 && ondisk->vol_rootvol == ondisk->vol_no) {
 245                 hmp->rootvol = volume;
 246                 if (bp) {
 247                         brelse(bp);
 248                         bp = NULL;
 249                 }
 250                 hmp->fsid_udev = dev2udev(vn_todev(volume->devvp));
 251                 hmp->mp->mnt_stat.f_blocks += ondisk->vol0_stat_bigblocks *
 252                         (HAMMER_LARGEBLOCK_SIZE / HAMMER_BUFSIZE);
 253         }
 254 late_failure:
 255         if (bp)
 256                 brelse(bp);
 257         if (error) {
 258                 /*vinvalbuf(volume->devvp, V_SAVE, 0, 0);*/
 259                 if (setmp)
 260                         volume->devvp->v_rdev->si_mountpoint = NULL;
 261                 VOP_CLOSE(volume->devvp, ronly ? FREAD : FREAD|FWRITE);
 262                 hammer_free_volume(volume);
 263         }
 264         return (error);
 265 }
 266
 267 /*
 268  * Unload and free a HAMMER volume.  Must return >= 0 to continue scan
 269  * so returns -1 on failure.
 270  */
 271 int
 272 hammer_unload_volume(hammer_volume_t volume, void *data __unused)
 273 {
 274         struct hammer_mount *hmp = volume->io.hmp;
 275         int ronly = ((hmp->mp->mnt_flag & MNT_RDONLY) ? 1 : 0);
 276
 277         /*
 278          * Clean up the root volume pointer, which is held unlocked in hmp.
 279          */
 280         if (hmp->rootvol == volume)
 281                 hmp->rootvol = NULL;
 282
 283         /*
 284          * Unload buffers.
 285          */
 286         RB_SCAN(hammer_buf_rb_tree, &volume->rb_bufs_root, NULL,
 287                         hammer_unload_buffer, NULL);
 288
 289         /*
 290          * Release our buffer and flush anything left in the buffer cache.
 291          */
 292         volume->io.waitdep = 1;
 293         hammer_io_release(&volume->io, 1);
 294
 295         /*
 296          * There should be no references on the volume, no clusters, and
 297          * no super-clusters.
 298          */
 299         KKASSERT(volume->io.lock.refs == 0);
 300         KKASSERT(RB_EMPTY(&volume->rb_bufs_root));
 301
 302         volume->ondisk = NULL;
 303         if (volume->devvp) {
 304                 if (volume->devvp->v_rdev &&
 305                     volume->devvp->v_rdev->si_mountpoint == hmp->mp
 306                 ) {
 307                         volume->devvp->v_rdev->si_mountpoint = NULL;
 308                 }
 309                 if (ronly) {
 310                         vinvalbuf(volume->devvp, 0, 0, 0);
 311                         VOP_CLOSE(volume->devvp, FREAD);
 312                 } else {
 313                         vinvalbuf(volume->devvp, V_SAVE, 0, 0);
 314                         VOP_CLOSE(volume->devvp, FREAD|FWRITE);
 315                 }
 316         }
 317
 318         /*
 319          * Destroy the structure
 320          */
 321         RB_REMOVE(hammer_vol_rb_tree, &hmp->rb_vols_root, volume);
 322         hammer_free_volume(volume);
 323         return(0);
 324 }
 325
 326 static
 327 void
 328 hammer_free_volume(hammer_volume_t volume)
 329 {
 330         if (volume->vol_name) {
 331                 kfree(volume->vol_name, M_HAMMER);
 332                 volume->vol_name = NULL;
 333         }
 334         if (volume->devvp) {
 335                 vrele(volume->devvp);
 336                 volume->devvp = NULL;
 337         }
 338         --hammer_count_volumes;
 339         kfree(volume, M_HAMMER);
 340 }
 341
 342 /*
 343  * Get a HAMMER volume.  The volume must already exist.
 344  */
 345 hammer_volume_t
 346 hammer_get_volume(struct hammer_mount *hmp, int32_t vol_no, int *errorp)
 347 {
 348         struct hammer_volume *volume;
 349
 350         /*
 351          * Locate the volume structure
 352          */
 353         volume = RB_LOOKUP(hammer_vol_rb_tree, &hmp->rb_vols_root, vol_no);
 354         if (volume == NULL) {
 355                 *errorp = ENOENT;
 356                 return(NULL);
 357         }
 358         hammer_ref(&volume->io.lock);
 359
 360         /*
 361          * Deal with on-disk info
 362          */
 363         if (volume->ondisk == NULL || volume->io.loading) {
 364                 *errorp = hammer_load_volume(volume);
 365                 if (*errorp) {
 366                         hammer_rel_volume(volume, 1);
 367                         volume = NULL;
 368                 }
 369         } else {
 370                 *errorp = 0;
 371         }
 372         return(volume);
 373 }
 374
 375 int
 376 hammer_ref_volume(hammer_volume_t volume)
 377 {
 378         int error;
 379
 380         hammer_ref(&volume->io.lock);
 381
 382         /*
 383          * Deal with on-disk info
 384          */
 385         if (volume->ondisk == NULL || volume->io.loading) {
 386                 error = hammer_load_volume(volume);
 387                 if (error)
 388                         hammer_rel_volume(volume, 1);
 389         } else {
 390                 error = 0;
 391         }
 392         return (error);
 393 }
 394
 395 hammer_volume_t
 396 hammer_get_root_volume(struct hammer_mount *hmp, int *errorp)
 397 {
 398         hammer_volume_t volume;
 399
 400         volume = hmp->rootvol;
 401         KKASSERT(volume != NULL);
 402         hammer_ref(&volume->io.lock);
 403
 404         /*
 405          * Deal with on-disk info
 406          */
 407         if (volume->ondisk == NULL || volume->io.loading) {
 408                 *errorp = hammer_load_volume(volume);
 409                 if (*errorp) {
 410                         hammer_rel_volume(volume, 1);
 411                         volume = NULL;
 412                 }
 413         } else {
 414                 *errorp = 0;
 415         }
 416         return (volume);
 417 }
 418
 419 /*
 420  * Load a volume's on-disk information.  The volume must be referenced and
 421  * not locked.  We temporarily acquire an exclusive lock to interlock
 422  * against releases or multiple get's.
 423  */
 424 static int
 425 hammer_load_volume(hammer_volume_t volume)
 426 {
 427         int error;
 428
 429         ++volume->io.loading;
 430         hammer_lock_ex(&volume->io.lock);
 431
 432         if (volume->ondisk == NULL) {
 433                 error = hammer_io_read(volume->devvp, &volume->io,
 434                                        volume->maxraw_off);
 435                 if (error == 0)
 436                         volume->ondisk = (void *)volume->io.bp->b_data;
 437         } else {
 438                 error = 0;
 439         }
 440         --volume->io.loading;
 441         hammer_unlock(&volume->io.lock);
 442         return(error);
 443 }
 444
 445 /*
 446  * Release a volume.  Call hammer_io_release on the last reference.  We have
 447  * to acquire an exclusive lock to interlock against volume->ondisk tests
 448  * in hammer_load_volume(), and hammer_io_release() also expects an exclusive
 449  * lock to be held.
 450  *
 451  * Volumes are not unloaded from memory during normal operation.
 452  */
 453 void
 454 hammer_rel_volume(hammer_volume_t volume, int flush)
 455 {
 456         crit_enter();
 457         if (volume->io.lock.refs == 1) {
 458                 ++volume->io.loading;
 459                 hammer_lock_ex(&volume->io.lock);
 460                 if (volume->io.lock.refs == 1) {
 461                         volume->ondisk = NULL;
 462                         hammer_io_release(&volume->io, flush);
 463                 }
 464                 --volume->io.loading;
 465                 hammer_unlock(&volume->io.lock);
 466         }
 467         hammer_unref(&volume->io.lock);
 468         crit_exit();
 469 }
 470
 471 /************************************************************************
 472  *                              BUFFERS                                 *
 473  ************************************************************************
 474  *
 475  * Manage buffers.  Currently all blockmap-backed zones are translated
 476  * to zone-2 buffer offsets.
 477  */
 478 hammer_buffer_t
 479 hammer_get_buffer(hammer_mount_t hmp, hammer_off_t buf_offset,
 480                   int isnew, int *errorp)
 481 {
 482         hammer_buffer_t buffer;
 483         hammer_volume_t volume;
 484         hammer_off_t    zoneX_offset;
 485         hammer_io_type_t iotype;
 486         int vol_no;
 487         int zone;
 488
 489         zoneX_offset = buf_offset;
 490         zone = HAMMER_ZONE_DECODE(buf_offset);
 491
 492         /*
 493          * What is the buffer class?
 494          */
 495         switch(zone) {
 496         case HAMMER_ZONE_LARGE_DATA_INDEX:
 497         case HAMMER_ZONE_SMALL_DATA_INDEX:
 498                 iotype = HAMMER_STRUCTURE_DATA_BUFFER;
 499                 break;
 500         case HAMMER_ZONE_UNDO_INDEX:
 501                 iotype = HAMMER_STRUCTURE_UNDO_BUFFER;
 502                 break;
 503         default:
 504                 iotype = HAMMER_STRUCTURE_META_BUFFER;
 505                 break;
 506         }
 507
 508         /*
 509          * Handle blockmap offset translations
 510          */
 511         if (zone >= HAMMER_ZONE_BTREE_INDEX) {
 512                 buf_offset = hammer_blockmap_lookup(hmp, buf_offset, errorp);
 513                 KKASSERT(*errorp == 0);
 514         } else if (zone == HAMMER_ZONE_UNDO_INDEX) {
 515                 buf_offset = hammer_undo_lookup(hmp, buf_offset, errorp);
 516                 KKASSERT(*errorp == 0);
 517         }
 518
 519         /*
 520          * Locate the buffer given its zone-2 offset.
 521          */
 522         buf_offset &= ~HAMMER_BUFMASK64;
 523         KKASSERT((buf_offset & HAMMER_OFF_ZONE_MASK) == HAMMER_ZONE_RAW_BUFFER);
 524         vol_no = HAMMER_VOL_DECODE(buf_offset);
 525         volume = hammer_get_volume(hmp, vol_no, errorp);
 526         if (volume == NULL)
 527                 return(NULL);
 528
 529         /*
 530          * NOTE: buf_offset and maxbuf_off are both full zone-2 offset
 531          * specifications.
 532          */
 533         KKASSERT(buf_offset < volume->maxbuf_off);
 534
 535         /*
 536          * Locate and lock the buffer structure, creating one if necessary.
 537          */
 538 again:
 539         buffer = RB_LOOKUP(hammer_buf_rb_tree, &volume->rb_bufs_root,
 540                            buf_offset);
 541         if (buffer == NULL) {
 542                 ++hammer_count_buffers;
 543                 buffer = kmalloc(sizeof(*buffer), M_HAMMER, M_WAITOK|M_ZERO);
 544                 buffer->zone2_offset = buf_offset;
 545                 buffer->volume = volume;
 546
 547                 hammer_io_init(&buffer->io, hmp, iotype);
 548                 buffer->io.offset = volume->ondisk->vol_buf_beg +
 549                                     (buf_offset & HAMMER_OFF_SHORT_MASK);
 550                 TAILQ_INIT(&buffer->clist);
 551                 hammer_ref(&buffer->io.lock);
 552
 553                 /*
 554                  * Insert the buffer into the RB tree and handle late
 555                  * collisions.
 556                  */
 557                 if (RB_INSERT(hammer_buf_rb_tree, &volume->rb_bufs_root, buffer)) {
 558                         hammer_unref(&buffer->io.lock);
 559                         --hammer_count_buffers;
 560                         kfree(buffer, M_HAMMER);
 561                         goto again;
 562                 }
 563                 hammer_ref(&volume->io.lock);
 564         } else {
 565                 hammer_ref(&buffer->io.lock);
 566
 567                 /*
 568                  * The buffer is no longer loose if it has a ref.
 569                  */
 570                 if (buffer->io.mod_list == &hmp->lose_list) {
 571                         TAILQ_REMOVE(buffer->io.mod_list, &buffer->io,
 572                                      mod_entry);
 573                         buffer->io.mod_list = NULL;
 574                 }
 575                 if (buffer->io.lock.refs == 1)
 576                         hammer_io_reinit(&buffer->io, iotype);
 577                 else
 578                         KKASSERT(buffer->io.type == iotype);
 579         }
 580
 581         /*
 582          * Cache the blockmap translation
 583          */
 584         if ((zoneX_offset & HAMMER_OFF_ZONE_MASK) != HAMMER_ZONE_RAW_BUFFER)
 585                 buffer->zoneX_offset = zoneX_offset;
 586
 587         /*
 588          * Deal with on-disk info
 589          */
 590         if (buffer->ondisk == NULL || buffer->io.loading) {
 591                 *errorp = hammer_load_buffer(buffer, isnew);
 592                 if (*errorp) {
 593                         hammer_rel_buffer(buffer, 1);
 594                         buffer = NULL;
 595                 }
 596         } else {
 597                 *errorp = 0;
 598         }
 599         hammer_rel_volume(volume, 0);
 600         return(buffer);
 601 }
 602
 603 /*
 604  * Clear the cached zone-X translation for a buffer.
 605  */
 606 void
 607 hammer_clrxlate_buffer(hammer_mount_t hmp, hammer_off_t buf_offset)
 608 {
 609         hammer_buffer_t buffer;
 610         hammer_volume_t volume;
 611         int vol_no;
 612         int error;
 613
 614         buf_offset &= ~HAMMER_BUFMASK64;
 615         KKASSERT((buf_offset & HAMMER_OFF_ZONE_MASK) == HAMMER_ZONE_RAW_BUFFER);
 616         vol_no = HAMMER_VOL_DECODE(buf_offset);
 617         volume = hammer_get_volume(hmp, vol_no, &error);
 618         if (volume == NULL)
 619                 return;
 620         buffer = RB_LOOKUP(hammer_buf_rb_tree, &volume->rb_bufs_root,
 621                            buf_offset);
 622         if (buffer)
 623                 buffer->zoneX_offset = 0;
 624         hammer_rel_volume(volume, 0);
 625 }
 626
 627 static int
 628 hammer_load_buffer(hammer_buffer_t buffer, int isnew)
 629 {
 630         hammer_volume_t volume;
 631         int error;
 632
 633         /*
 634          * Load the buffer's on-disk info
 635          */
 636         volume = buffer->volume;
 637         ++buffer->io.loading;
 638         hammer_lock_ex(&buffer->io.lock);
 639
 640         if (hammer_debug_io & 0x0001) {
 641                 kprintf("load_buffer %016llx %016llx\n",
 642                         buffer->zoneX_offset, buffer->zone2_offset);
 643         }
 644
 645         if (buffer->ondisk == NULL) {
 646                 if (isnew) {
 647                         error = hammer_io_new(volume->devvp, &buffer->io);
 648                 } else {
 649                         error = hammer_io_read(volume->devvp, &buffer->io,
 650                                                volume->maxraw_off);
 651                 }
 652                 if (error == 0)
 653                         buffer->ondisk = (void *)buffer->io.bp->b_data;
 654         } else if (isnew) {
 655                 error = hammer_io_new(volume->devvp, &buffer->io);
 656         } else {
 657                 error = 0;
 658         }
 659         --buffer->io.loading;
 660         hammer_unlock(&buffer->io.lock);
 661         return (error);
 662 }
 663
 664 /*
 665  * NOTE: Called from RB_SCAN, must return >= 0 for scan to continue.
 666  */
 667 int
 668 hammer_unload_buffer(hammer_buffer_t buffer, void *data __unused)
 669 {
 670         hammer_ref(&buffer->io.lock);
 671         hammer_flush_buffer_nodes(buffer);
 672         KKASSERT(buffer->io.lock.refs == 1);
 673         hammer_rel_buffer(buffer, 2);
 674         return(0);
 675 }
 676
 677 /*
 678  * Reference a buffer that is either already referenced or via a specially
 679  * handled pointer (aka cursor->buffer).
 680  */
 681 int
 682 hammer_ref_buffer(hammer_buffer_t buffer)
 683 {
 684         int error;
 685
 686         hammer_ref(&buffer->io.lock);
 687
 688         /*
 689          * No longer loose
 690          */
 691         if (buffer->io.mod_list == &buffer->io.hmp->lose_list) {
 692                 TAILQ_REMOVE(buffer->io.mod_list, &buffer->io, mod_entry);
 693                 buffer->io.mod_list = NULL;
 694         }
 695
 696         if (buffer->ondisk == NULL || buffer->io.loading) {
 697                 error = hammer_load_buffer(buffer, 0);
 698                 if (error) {
 699                         hammer_rel_buffer(buffer, 1);
 700                         /*
 701                          * NOTE: buffer pointer can become stale after
 702                          * the above release.
 703                          */
 704                 }
 705         } else {
 706                 error = 0;
 707         }
 708         return(error);
 709 }
 710
 711 /*
 712  * Release a buffer.  We have to deal with several places where
 713  * another thread can ref the buffer.
 714  *
 715  * Only destroy the structure itself if the related buffer cache buffer
 716  * was disassociated from it.  This ties the management of the structure
 717  * to the buffer cache subsystem.  buffer->ondisk determines whether the
 718  * embedded io is referenced or not.
 719  */
 720 void
 721 hammer_rel_buffer(hammer_buffer_t buffer, int flush)
 722 {
 723         hammer_volume_t volume;
 724         int freeme = 0;
 725
 726         crit_enter();
 727         if (buffer->io.lock.refs == 1) {
 728                 ++buffer->io.loading;   /* force interlock check */
 729                 hammer_lock_ex(&buffer->io.lock);
 730                 if (buffer->io.lock.refs == 1) {
 731                         hammer_io_release(&buffer->io, flush);
 732                         hammer_flush_buffer_nodes(buffer);
 733                         KKASSERT(TAILQ_EMPTY(&buffer->clist));
 734
 735                         if (buffer->io.bp == NULL &&
 736                             buffer->io.lock.refs == 1) {
 737                                 /*
 738                                  * Final cleanup
 739                                  */
 740                                 volume = buffer->volume;
 741                                 RB_REMOVE(hammer_buf_rb_tree,
 742                                           &volume->rb_bufs_root, buffer);
 743                                 buffer->volume = NULL; /* sanity */
 744                                 hammer_rel_volume(volume, 0);
 745                                 freeme = 1;
 746                         }
 747                 }
 748                 --buffer->io.loading;
 749                 hammer_unlock(&buffer->io.lock);
 750         }
 751         hammer_unref(&buffer->io.lock);
 752         crit_exit();
 753         if (freeme) {
 754                 KKASSERT(buffer->io.mod_list == NULL);
 755                 --hammer_count_buffers;
 756                 kfree(buffer, M_HAMMER);
 757         }
 758 }
 759
 760 /*
 761  * Remove the zoneX translation cache for a buffer given its zone-2 offset.
 762  */
 763 void
 764 hammer_uncache_buffer(hammer_mount_t hmp, hammer_off_t buf_offset)
 765 {
 766         hammer_volume_t volume;
 767         hammer_buffer_t buffer;
 768         int vol_no;
 769         int error;
 770
 771         buf_offset &= ~HAMMER_BUFMASK64;
 772         KKASSERT((buf_offset & HAMMER_OFF_ZONE_MASK) == HAMMER_ZONE_RAW_BUFFER);
 773         vol_no = HAMMER_VOL_DECODE(buf_offset);
 774         volume = hammer_get_volume(hmp, vol_no, &error);
 775         KKASSERT(volume != 0);
 776         KKASSERT(buf_offset < volume->maxbuf_off);
 777
 778         buffer = RB_LOOKUP(hammer_buf_rb_tree, &volume->rb_bufs_root,
 779                            buf_offset);
 780         if (buffer)
 781                 buffer->zoneX_offset = 0;
 782         hammer_rel_volume(volume, 0);
 783 }
 784
 785 /*
 786  * Access the filesystem buffer containing the specified hammer offset.
 787  * buf_offset is a conglomeration of the volume number and vol_buf_beg
 788  * relative buffer offset.  It must also have bit 55 set to be valid.
 789  * (see hammer_off_t in hammer_disk.h).
 790  *
 791  * Any prior buffer in *bufferp will be released and replaced by the
 792  * requested buffer.
 793  */
 794 void *
 795 hammer_bread(hammer_mount_t hmp, hammer_off_t buf_offset, int *errorp,
 796              struct hammer_buffer **bufferp)
 797 {
 798         hammer_buffer_t buffer;
 799         int32_t xoff = (int32_t)buf_offset & HAMMER_BUFMASK;
 800
 801         buf_offset &= ~HAMMER_BUFMASK64;
 802         KKASSERT((buf_offset & HAMMER_OFF_ZONE_MASK) != 0);
 803
 804         buffer = *bufferp;
 805         if (buffer == NULL || (buffer->zone2_offset != buf_offset &&
 806                                buffer->zoneX_offset != buf_offset)) {
 807                 if (buffer)
 808                         hammer_rel_buffer(buffer, 0);
 809                 buffer = hammer_get_buffer(hmp, buf_offset, 0, errorp);
 810                 *bufferp = buffer;
 811         } else {
 812                 *errorp = 0;
 813         }
 814
 815         /*
 816          * Return a pointer to the buffer data.
 817          */
 818         if (buffer == NULL)
 819                 return(NULL);
 820         else
 821                 return((char *)buffer->ondisk + xoff);
 822 }
 823
 824 /*
 825  * Access the filesystem buffer containing the specified hammer offset.
 826  * No disk read operation occurs.  The result buffer may contain garbage.
 827  *
 828  * Any prior buffer in *bufferp will be released and replaced by the
 829  * requested buffer.
 830  *
 831  * This function marks the buffer dirty but does not increment its
 832  * modify_refs count.
 833  */
 834 void *
 835 hammer_bnew(hammer_mount_t hmp, hammer_off_t buf_offset, int *errorp,
 836              struct hammer_buffer **bufferp)
 837 {
 838         hammer_buffer_t buffer;
 839         int32_t xoff = (int32_t)buf_offset & HAMMER_BUFMASK;
 840
 841         buf_offset &= ~HAMMER_BUFMASK64;
 842
 843         buffer = *bufferp;
 844         if (buffer == NULL || (buffer->zone2_offset != buf_offset &&
 845                                buffer->zoneX_offset != buf_offset)) {
 846                 if (buffer)
 847                         hammer_rel_buffer(buffer, 0);
 848                 buffer = hammer_get_buffer(hmp, buf_offset, 1, errorp);
 849                 *bufferp = buffer;
 850         } else {
 851                 *errorp = 0;
 852         }
 853
 854         /*
 855          * Return a pointer to the buffer data.
 856          */
 857         if (buffer == NULL)
 858                 return(NULL);
 859         else
 860                 return((char *)buffer->ondisk + xoff);
 861 }
 862
 863 /************************************************************************
 864  *                              NODES                                   *
 865  ************************************************************************
 866  *
 867  * Manage B-Tree nodes.  B-Tree nodes represent the primary indexing
 868  * method used by the HAMMER filesystem.
 869  *
 870  * Unlike other HAMMER structures, a hammer_node can be PASSIVELY
 871  * associated with its buffer, and will only referenced the buffer while
 872  * the node itself is referenced.
 873  *
 874  * A hammer_node can also be passively associated with other HAMMER
 875  * structures, such as inodes, while retaining 0 references.  These
 876  * associations can be cleared backwards using a pointer-to-pointer in
 877  * the hammer_node.
 878  *
 879  * This allows the HAMMER implementation to cache hammer_nodes long-term
 880  * and short-cut a great deal of the infrastructure's complexity.  In
 881  * most cases a cached node can be reacquired without having to dip into
 882  * either the buffer or cluster management code.
 883  *
 884  * The caller must pass a referenced cluster on call and will retain
 885  * ownership of the reference on return.  The node will acquire its own
 886  * additional references, if necessary.
 887  */
 888 hammer_node_t
 889 hammer_get_node(hammer_mount_t hmp, hammer_off_t node_offset,
 890                 int isnew, int *errorp)
 891 {
 892         hammer_node_t node;
 893
 894         KKASSERT((node_offset & HAMMER_OFF_ZONE_MASK) == HAMMER_ZONE_BTREE);
 895
 896         /*
 897          * Locate the structure, allocating one if necessary.
 898          */
 899 again:
 900         node = RB_LOOKUP(hammer_nod_rb_tree, &hmp->rb_nods_root, node_offset);
 901         if (node == NULL) {
 902                 ++hammer_count_nodes;
 903                 node = kmalloc(sizeof(*node), M_HAMMER, M_WAITOK|M_ZERO);
 904                 node->node_offset = node_offset;
 905                 node->hmp = hmp;
 906                 if (RB_INSERT(hammer_nod_rb_tree, &hmp->rb_nods_root, node)) {
 907                         --hammer_count_nodes;
 908                         kfree(node, M_HAMMER);
 909                         goto again;
 910                 }
 911         }
 912         hammer_ref(&node->lock);
 913         if (node->ondisk)
 914                 *errorp = 0;
 915         else
 916                 *errorp = hammer_load_node(node, isnew);
 917         if (*errorp) {
 918                 hammer_rel_node(node);
 919                 node = NULL;
 920         }
 921         return(node);
 922 }
 923
 924 /*
 925  * Reference an already-referenced node.
 926  */
 927 void
 928 hammer_ref_node(hammer_node_t node)
 929 {
 930         KKASSERT(node->lock.refs > 0 && node->ondisk != NULL);
 931         hammer_ref(&node->lock);
 932 }
 933
 934 /*
 935  * Load a node's on-disk data reference.
 936  */
 937 static int
 938 hammer_load_node(hammer_node_t node, int isnew)
 939 {
 940         hammer_buffer_t buffer;
 941         hammer_off_t buf_offset;
 942         int error;
 943
 944         error = 0;
 945         ++node->loading;
 946         hammer_lock_ex(&node->lock);
 947         if (node->ondisk == NULL) {
 948                 /*
 949                  * This is a little confusing but the jist is that
 950                  * node->buffer determines whether the node is on
 951                  * the buffer's clist and node->ondisk determines
 952                  * whether the buffer is referenced.
 953                  *
 954                  * We could be racing a buffer release, in which case
 955                  * node->buffer may become NULL while we are blocked
 956                  * referencing the buffer.
 957                  */
 958                 if ((buffer = node->buffer) != NULL) {
 959                         error = hammer_ref_buffer(buffer);
 960                         if (error == 0 && node->buffer == NULL) {
 961                                 TAILQ_INSERT_TAIL(&buffer->clist,
 962                                                   node, entry);
 963                                 node->buffer = buffer;
 964                         }
 965                 } else {
 966                         buf_offset = node->node_offset & ~HAMMER_BUFMASK64;
 967                         buffer = hammer_get_buffer(node->hmp, buf_offset,
 968                                                    0, &error);
 969                         if (buffer) {
 970                                 KKASSERT(error == 0);
 971                                 TAILQ_INSERT_TAIL(&buffer->clist,
 972                                                   node, entry);
 973                                 node->buffer = buffer;
 974                         }
 975                 }
 976                 if (error == 0) {
 977                         node->ondisk = (void *)((char *)buffer->ondisk +
 978                                (node->node_offset & HAMMER_BUFMASK));
 979                         if (isnew == 0 &&
 980                             hammer_crc_test_btree(node->ondisk) == 0) {
 981                                 Debugger("CRC FAILED: B-TREE NODE");
 982                         }
 983                 }
 984         }
 985         --node->loading;
 986         hammer_unlock(&node->lock);
 987         return (error);
 988 }
 989
 990 /*
 991  * Safely reference a node, interlock against flushes via the IO subsystem.
 992  */
 993 hammer_node_t
 994 hammer_ref_node_safe(struct hammer_mount *hmp, struct hammer_node **cache,
 995                      int *errorp)
 996 {
 997         hammer_node_t node;
 998
 999         node = *cache;
1000         if (node != NULL) {
1001                 hammer_ref(&node->lock);
1002                 if (node->ondisk)
1003                         *errorp = 0;
1004                 else
1005                         *errorp = hammer_load_node(node, 0);
1006                 if (*errorp) {
1007                         hammer_rel_node(node);
1008                         node = NULL;
1009                 }
1010         } else {
1011                 *errorp = ENOENT;
1012         }
1013         return(node);
1014 }
1015
1016 /*
1017  * Release a hammer_node.  On the last release the node dereferences
1018  * its underlying buffer and may or may not be destroyed.
1019  */
1020 void
1021 hammer_rel_node(hammer_node_t node)
1022 {
1023         hammer_buffer_t buffer;
1024
1025         /*
1026          * If this isn't the last ref just decrement the ref count and
1027          * return.
1028          */
1029         if (node->lock.refs > 1) {
1030                 hammer_unref(&node->lock);
1031                 return;
1032         }
1033
1034         /*
1035          * If there is no ondisk info or no buffer the node failed to load,
1036          * remove the last reference and destroy the node.
1037          */
1038         if (node->ondisk == NULL) {
1039                 hammer_unref(&node->lock);
1040                 hammer_flush_node(node);
1041                 /* node is stale now */
1042                 return;
1043         }
1044
1045         /*
1046          * Do final cleanups and then either destroy the node and leave it
1047          * passively cached.  The buffer reference is removed regardless.
1048          */
1049         buffer = node->buffer;
1050         node->ondisk = NULL;
1051
1052         if ((node->flags & HAMMER_NODE_FLUSH) == 0) {
1053                 hammer_unref(&node->lock);
1054                 hammer_rel_buffer(buffer, 0);
1055                 return;
1056         }
1057
1058         /*
1059          * Destroy the node.
1060          */
1061         hammer_unref(&node->lock);
1062         hammer_flush_node(node);
1063         /* node is stale */
1064         hammer_rel_buffer(buffer, 0);
1065 }
1066
1067 /*
1068  * Free space on-media associated with a B-Tree node.
1069  */
1070 void
1071 hammer_delete_node(hammer_transaction_t trans, hammer_node_t node)
1072 {
1073         KKASSERT((node->flags & HAMMER_NODE_DELETED) == 0);
1074         node->flags |= HAMMER_NODE_DELETED;
1075         hammer_blockmap_free(trans, node->node_offset, sizeof(*node->ondisk));
1076 }
1077
1078 /*
1079  * Passively cache a referenced hammer_node in *cache.  The caller may
1080  * release the node on return.
1081  */
1082 void
1083 hammer_cache_node(hammer_node_t node, struct hammer_node **cache)
1084 {
1085         hammer_node_t old;
1086
1087         /*
1088          * If the node is being deleted, don't cache it!
1089          */
1090         if (node->flags & HAMMER_NODE_DELETED)
1091                 return;
1092
1093         /*
1094          * Cache the node.  If we previously cached a different node we
1095          * have to give HAMMER a chance to destroy it.
1096          */
1097 again:
1098         if (node->cache1 != cache) {
1099                 if (node->cache2 != cache) {
1100                         if ((old = *cache) != NULL) {
1101                                 KKASSERT(node->lock.refs != 0);
1102                                 hammer_uncache_node(cache);
1103                                 goto again;
1104                         }
1105                         if (node->cache2)
1106                                 *node->cache2 = NULL;
1107                         node->cache2 = node->cache1;
1108                         node->cache1 = cache;
1109                         *cache = node;
1110                 } else {
1111                         struct hammer_node **tmp;
1112                         tmp = node->cache1;
1113                         node->cache1 = node->cache2;
1114                         node->cache2 = tmp;
1115                 }
1116         }
1117 }
1118
1119 void
1120 hammer_uncache_node(struct hammer_node **cache)
1121 {
1122         hammer_node_t node;
1123
1124         if ((node = *cache) != NULL) {
1125                 *cache = NULL;
1126                 if (node->cache1 == cache) {
1127                         node->cache1 = node->cache2;
1128                         node->cache2 = NULL;
1129                 } else if (node->cache2 == cache) {
1130                         node->cache2 = NULL;
1131                 } else {
1132                         panic("hammer_uncache_node: missing cache linkage");
1133                 }
1134                 if (node->cache1 == NULL && node->cache2 == NULL)
1135                         hammer_flush_node(node);
1136         }
1137 }
1138
1139 /*
1140  * Remove a node's cache references and destroy the node if it has no
1141  * other references or backing store.
1142  */
1143 void
1144 hammer_flush_node(hammer_node_t node)
1145 {
1146         hammer_buffer_t buffer;
1147
1148         if (node->cache1)
1149                 *node->cache1 = NULL;
1150         if (node->cache2)
1151                 *node->cache2 = NULL;
1152         if (node->lock.refs == 0 && node->ondisk == NULL) {
1153                 RB_REMOVE(hammer_nod_rb_tree, &node->hmp->rb_nods_root, node);
1154                 if ((buffer = node->buffer) != NULL) {
1155                         node->buffer = NULL;
1156                         TAILQ_REMOVE(&buffer->clist, node, entry);
1157                         /* buffer is unreferenced because ondisk is NULL */
1158                 }
1159                 --hammer_count_nodes;
1160                 kfree(node, M_HAMMER);
1161         }
1162 }
1163
1164 /*
1165  * Flush passively cached B-Tree nodes associated with this buffer.
1166  * This is only called when the buffer is about to be destroyed, so
1167  * none of the nodes should have any references.  The buffer is locked.
1168  *
1169  * We may be interlocked with the buffer.
1170  */
1171 void
1172 hammer_flush_buffer_nodes(hammer_buffer_t buffer)
1173 {
1174         hammer_node_t node;
1175
1176         while ((node = TAILQ_FIRST(&buffer->clist)) != NULL) {
1177                 KKASSERT(node->ondisk == NULL);
1178
1179                 if (node->lock.refs == 0) {
1180                         hammer_ref(&node->lock);
1181                         node->flags |= HAMMER_NODE_FLUSH;
1182                         hammer_rel_node(node);
1183                 } else {
1184                         KKASSERT(node->loading != 0);
1185                         KKASSERT(node->buffer != NULL);
1186                         buffer = node->buffer;
1187                         node->buffer = NULL;
1188                         TAILQ_REMOVE(&buffer->clist, node, entry);
1189                         /* buffer is unreferenced because ondisk is NULL */
1190                 }
1191         }
1192 }
1193
1194
1195 /************************************************************************
1196  *                              ALLOCATORS                              *
1197  ************************************************************************/
1198
1199 /*
1200  * Allocate a B-Tree node.
1201  */
1202 hammer_node_t
1203 hammer_alloc_btree(hammer_transaction_t trans, int *errorp)
1204 {
1205         hammer_buffer_t buffer = NULL;
1206         hammer_node_t node = NULL;
1207         hammer_off_t node_offset;
1208
1209         node_offset = hammer_blockmap_alloc(trans, HAMMER_ZONE_BTREE_INDEX,
1210                                             sizeof(struct hammer_node_ondisk),
1211                                             errorp);
1212         if (*errorp == 0) {
1213                 node = hammer_get_node(trans->hmp, node_offset, 1, errorp);
1214                 hammer_modify_node_noundo(trans, node);
1215                 bzero(node->ondisk, sizeof(*node->ondisk));
1216                 hammer_modify_node_done(node);
1217         }
1218         if (buffer)
1219                 hammer_rel_buffer(buffer, 0);
1220         return(node);
1221 }
1222
1223 #if 0
1224
1225 /*
1226  * The returned buffers are already appropriately marked as being modified.
1227  * If the caller marks them again unnecessary undo records may be generated.
1228  *
1229  * In-band data is indicated by data_bufferp == NULL.  Pass a data_len of 0
1230  * for zero-fill (caller modifies data_len afterwords).
1231  *
1232  * If the caller is responsible for calling hammer_modify_*() prior to making
1233  * any additional modifications to either the returned record buffer or the
1234  * returned data buffer.
1235  */
1236 void *
1237 hammer_alloc_record(hammer_transaction_t trans,
1238                     hammer_off_t *rec_offp, u_int16_t rec_type,
1239                     struct hammer_buffer **rec_bufferp,
1240                     int32_t data_len, void **datap,
1241                     hammer_off_t *data_offp,
1242                     struct hammer_buffer **data_bufferp, int *errorp)
1243 {
1244         hammer_record_ondisk_t rec;
1245         hammer_off_t rec_offset;
1246         hammer_off_t data_offset;
1247         int32_t reclen;
1248
1249         if (datap)
1250                 *datap = NULL;
1251
1252         /*
1253          * Allocate the record
1254          */
1255         rec_offset = hammer_blockmap_alloc(trans, HAMMER_ZONE_RECORD_INDEX,
1256                                            HAMMER_RECORD_SIZE, errorp);
1257         if (*errorp)
1258                 return(NULL);
1259         if (data_offp)
1260                 *data_offp = 0;
1261
1262         /*
1263          * Allocate data
1264          */
1265         if (data_len) {
1266                 if (data_bufferp == NULL) {
1267                         switch(rec_type) {
1268                         case HAMMER_RECTYPE_DATA:
1269                                 reclen = offsetof(struct hammer_data_record,
1270                                                   data[0]);
1271                                 break;
1272                         case HAMMER_RECTYPE_DIRENTRY:
1273                                 reclen = offsetof(struct hammer_entry_record,
1274                                                   name[0]);
1275                                 break;
1276                         default:
1277                                 panic("hammer_alloc_record: illegal "
1278                                       "in-band data");
1279                                 /* NOT REACHED */
1280                                 reclen = 0;
1281                                 break;
1282                         }
1283                         KKASSERT(reclen + data_len <= HAMMER_RECORD_SIZE);
1284                         data_offset = rec_offset + reclen;
1285                 } else if (data_len < HAMMER_BUFSIZE) {
1286                         data_offset = hammer_blockmap_alloc(trans,
1287                                                 HAMMER_ZONE_SMALL_DATA_INDEX,
1288                                                 data_len, errorp);
1289                         *data_offp = data_offset;
1290                 } else {
1291                         data_offset = hammer_blockmap_alloc(trans,
1292                                                 HAMMER_ZONE_LARGE_DATA_INDEX,
1293                                                 data_len, errorp);
1294                         *data_offp = data_offset;
1295                 }
1296         } else {
1297                 data_offset = 0;
1298         }
1299         if (*errorp) {
1300                 hammer_blockmap_free(trans, rec_offset, HAMMER_RECORD_SIZE);
1301                 return(NULL);
1302         }
1303
1304         /*
1305          * Basic return values.
1306          *
1307          * Note that because this is a 'new' buffer, there is no need to
1308          * generate UNDO records for it.
1309          */
1310         *rec_offp = rec_offset;
1311         rec = hammer_bread(trans->hmp, rec_offset, errorp, rec_bufferp);
1312         hammer_modify_buffer(trans, *rec_bufferp, NULL, 0);
1313         bzero(rec, sizeof(*rec));
1314         KKASSERT(*errorp == 0);
1315         rec->base.data_off = data_offset;
1316         rec->base.data_len = data_len;
1317         hammer_modify_buffer_done(*rec_bufferp);
1318
1319         if (data_bufferp) {
1320                 if (data_len) {
1321                         *datap = hammer_bread(trans->hmp, data_offset, errorp,
1322                                               data_bufferp);
1323                         KKASSERT(*errorp == 0);
1324                 } else {
1325                         *datap = NULL;
1326                 }
1327         } else if (data_len) {
1328                 KKASSERT(data_offset + data_len - rec_offset <=
1329                          HAMMER_RECORD_SIZE);
1330                 if (datap) {
1331                         *datap = (void *)((char *)rec +
1332                                           (int32_t)(data_offset - rec_offset));
1333                 }
1334         } else {
1335                 KKASSERT(datap == NULL);
1336         }
1337         KKASSERT(*errorp == 0);
1338         return(rec);
1339 }
1340
1341 #endif
1342
1343 /*
1344  * Allocate data.  If the address of a data buffer is supplied then
1345  * any prior non-NULL *data_bufferp will be released and *data_bufferp
1346  * will be set to the related buffer.  The caller must release it when
1347  * finally done.  The initial *data_bufferp should be set to NULL by
1348  * the caller.
1349  *
1350  * The caller is responsible for making hammer_modify*() calls on the
1351  * *data_bufferp.
1352  */
1353 void *
1354 hammer_alloc_data(hammer_transaction_t trans, int32_t data_len,
1355                   hammer_off_t *data_offsetp,
1356                   struct hammer_buffer **data_bufferp, int *errorp)
1357 {
1358         void *data;
1359
1360         /*
1361          * Allocate data
1362          */
1363         if (data_len) {
1364                 if (data_len < HAMMER_BUFSIZE) {
1365                         *data_offsetp = hammer_blockmap_alloc(trans,
1366                                                 HAMMER_ZONE_SMALL_DATA_INDEX,
1367                                                 data_len, errorp);
1368                 } else {
1369                         *data_offsetp = hammer_blockmap_alloc(trans,
1370                                                 HAMMER_ZONE_LARGE_DATA_INDEX,
1371                                                 data_len, errorp);
1372                 }
1373         } else {
1374                 *data_offsetp = 0;
1375         }
1376         if (*errorp == 0 && data_bufferp) {
1377                 if (data_len) {
1378                         data = hammer_bread(trans->hmp, *data_offsetp, errorp,
1379                                             data_bufferp);
1380                         KKASSERT(*errorp == 0);
1381                 } else {
1382                         data = NULL;
1383                 }
1384         } else {
1385                 data = NULL;
1386         }
1387         KKASSERT(*errorp == 0);
1388         return(data);
1389 }
1390
1391 /*
1392  * Sync dirty buffers to the media and clean-up any loose ends.
1393  */
1394 static int hammer_sync_scan1(struct mount *mp, struct vnode *vp, void *data);
1395 static int hammer_sync_scan2(struct mount *mp, struct vnode *vp, void *data);
1396
1397 int
1398 hammer_queue_inodes_flusher(hammer_mount_t hmp, int waitfor)
1399 {
1400         struct hammer_sync_info info;
1401
1402         info.error = 0;
1403         info.waitfor = waitfor;
1404         if (waitfor == MNT_WAIT) {
1405                 vmntvnodescan(hmp->mp, VMSC_GETVP,
1406                               hammer_sync_scan1, hammer_sync_scan2, &info);
1407         } else {
1408                 vmntvnodescan(hmp->mp, VMSC_GETVP|VMSC_NOWAIT,
1409                               hammer_sync_scan1, hammer_sync_scan2, &info);
1410         }
1411         return(info.error);
1412 }
1413
1414 int
1415 hammer_sync_hmp(hammer_mount_t hmp, int waitfor)
1416 {
1417         struct hammer_sync_info info;
1418
1419         info.error = 0;
1420         info.waitfor = waitfor;
1421
1422         vmntvnodescan(hmp->mp, VMSC_GETVP|VMSC_NOWAIT,
1423                       hammer_sync_scan1, hammer_sync_scan2, &info);
1424         if (waitfor == MNT_WAIT)
1425                 hammer_flusher_sync(hmp);
1426         else
1427                 hammer_flusher_async(hmp);
1428
1429         return(info.error);
1430 }
1431
1432 static int
1433 hammer_sync_scan1(struct mount *mp, struct vnode *vp, void *data)
1434 {
1435         struct hammer_inode *ip;
1436
1437         ip = VTOI(vp);
1438         if (vp->v_type == VNON || ip == NULL ||
1439             ((ip->flags & HAMMER_INODE_MODMASK) == 0 &&
1440              RB_EMPTY(&vp->v_rbdirty_tree))) {
1441                 return(-1);
1442         }
1443         return(0);
1444 }
1445
1446 static int
1447 hammer_sync_scan2(struct mount *mp, struct vnode *vp, void *data)
1448 {
1449         struct hammer_sync_info *info = data;
1450         struct hammer_inode *ip;
1451         int error;
1452
1453         ip = VTOI(vp);
1454         if (vp->v_type == VNON || vp->v_type == VBAD ||
1455             ((ip->flags & HAMMER_INODE_MODMASK) == 0 &&
1456              RB_EMPTY(&vp->v_rbdirty_tree))) {
1457                 return(0);
1458         }
1459         error = VOP_FSYNC(vp, info->waitfor);
1460         if (error)
1461                 info->error = error;
1462         return(0);
1463 }
1464