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 1.37 2008/04/24 21:20:33 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);
  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         volume->hmp = hmp;
 161         hammer_io_init(&volume->io, HAMMER_STRUCTURE_VOLUME);
 162         volume->io.offset = 0LL;
 163
 164         /*
 165          * Get the device vnode
 166          */
 167         error = nlookup_init(&nd, volume->vol_name, UIO_SYSSPACE, NLC_FOLLOW);
 168         if (error == 0)
 169                 error = nlookup(&nd);
 170         if (error == 0)
 171                 error = cache_vref(&nd.nl_nch, nd.nl_cred, &volume->devvp);
 172         nlookup_done(&nd);
 173         if (error == 0) {
 174                 if (vn_isdisk(volume->devvp, &error)) {
 175                         error = vfs_mountedon(volume->devvp);
 176                 }
 177         }
 178         if (error == 0 &&
 179             count_udev(volume->devvp->v_umajor, volume->devvp->v_uminor) > 0) {
 180                 error = EBUSY;
 181         }
 182         if (error == 0) {
 183                 vn_lock(volume->devvp, LK_EXCLUSIVE | LK_RETRY);
 184                 error = vinvalbuf(volume->devvp, V_SAVE, 0, 0);
 185                 if (error == 0) {
 186                         error = VOP_OPEN(volume->devvp,
 187                                          (ronly ? FREAD : FREAD|FWRITE),
 188                                          FSCRED, NULL);
 189                 }
 190                 vn_unlock(volume->devvp);
 191         }
 192         if (error) {
 193                 hammer_free_volume(volume);
 194                 return(error);
 195         }
 196         volume->devvp->v_rdev->si_mountpoint = mp;
 197         setmp = 1;
 198
 199         /*
 200          * Extract the volume number from the volume header and do various
 201          * sanity checks.
 202          */
 203         error = bread(volume->devvp, 0LL, HAMMER_BUFSIZE, &bp);
 204         if (error)
 205                 goto late_failure;
 206         ondisk = (void *)bp->b_data;
 207         if (ondisk->vol_signature != HAMMER_FSBUF_VOLUME) {
 208                 kprintf("hammer_mount: volume %s has an invalid header\n",
 209                         volume->vol_name);
 210                 error = EFTYPE;
 211                 goto late_failure;
 212         }
 213         volume->vol_no = ondisk->vol_no;
 214         volume->buffer_base = ondisk->vol_buf_beg;
 215         volume->vol_flags = ondisk->vol_flags;
 216         volume->nblocks = ondisk->vol_nblocks;
 217         volume->maxbuf_off = HAMMER_ENCODE_RAW_BUFFER(volume->vol_no,
 218                                     ondisk->vol_buf_end - ondisk->vol_buf_beg);
 219         RB_INIT(&volume->rb_bufs_root);
 220
 221         hmp->mp->mnt_stat.f_blocks += volume->nblocks;
 222
 223         if (RB_EMPTY(&hmp->rb_vols_root)) {
 224                 hmp->fsid = ondisk->vol_fsid;
 225         } else if (bcmp(&hmp->fsid, &ondisk->vol_fsid, sizeof(uuid_t))) {
 226                 kprintf("hammer_mount: volume %s's fsid does not match "
 227                         "other volumes\n", volume->vol_name);
 228                 error = EFTYPE;
 229                 goto late_failure;
 230         }
 231
 232         /*
 233          * Insert the volume structure into the red-black tree.
 234          */
 235         if (RB_INSERT(hammer_vol_rb_tree, &hmp->rb_vols_root, volume)) {
 236                 kprintf("hammer_mount: volume %s has a duplicate vol_no %d\n",
 237                         volume->vol_name, volume->vol_no);
 238                 error = EEXIST;
 239         }
 240
 241         /*
 242          * Set the root volume .  HAMMER special cases rootvol the structure.
 243          * We do not hold a ref because this would prevent related I/O
 244          * from being flushed.
 245          */
 246         if (error == 0 && ondisk->vol_rootvol == ondisk->vol_no) {
 247                 hmp->rootvol = volume;
 248                 if (bp) {
 249                         brelse(bp);
 250                         bp = NULL;
 251                 }
 252                 hmp->fsid_udev = dev2udev(vn_todev(volume->devvp));
 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->hmp;
 275         int ronly = ((hmp->mp->mnt_flag & MNT_RDONLY) ? 1 : 0);
 276
 277         /*
 278          * Sync clusters, sync volume
 279          */
 280
 281         hmp->mp->mnt_stat.f_blocks -= volume->nblocks;
 282
 283         /*
 284          * Clean up the root volume pointer, which is held unlocked in hmp.
 285          */
 286         if (hmp->rootvol == volume)
 287                 hmp->rootvol = NULL;
 288
 289         /*
 290          * Unload buffers.
 291          */
 292         RB_SCAN(hammer_buf_rb_tree, &volume->rb_bufs_root, NULL,
 293                         hammer_unload_buffer, NULL);
 294
 295         /*
 296          * Release our buffer and flush anything left in the buffer cache.
 297          */
 298         volume->io.flush = 1;
 299         volume->io.waitdep = 1;
 300         hammer_io_release(&volume->io);
 301
 302         /*
 303          * There should be no references on the volume, no clusters, and
 304          * no super-clusters.
 305          */
 306         KKASSERT(volume->io.lock.refs == 0);
 307         KKASSERT(RB_EMPTY(&volume->rb_bufs_root));
 308
 309         volume->ondisk = NULL;
 310         if (volume->devvp) {
 311                 if (volume->devvp->v_rdev &&
 312                     volume->devvp->v_rdev->si_mountpoint == hmp->mp
 313                 ) {
 314                         volume->devvp->v_rdev->si_mountpoint = NULL;
 315                 }
 316                 if (ronly) {
 317                         vinvalbuf(volume->devvp, 0, 0, 0);
 318                         VOP_CLOSE(volume->devvp, FREAD);
 319                 } else {
 320                         vinvalbuf(volume->devvp, V_SAVE, 0, 0);
 321                         VOP_CLOSE(volume->devvp, FREAD|FWRITE);
 322                 }
 323         }
 324
 325         /*
 326          * Destroy the structure
 327          */
 328         RB_REMOVE(hammer_vol_rb_tree, &hmp->rb_vols_root, volume);
 329         hammer_free_volume(volume);
 330         return(0);
 331 }
 332
 333 static
 334 void
 335 hammer_free_volume(hammer_volume_t volume)
 336 {
 337         if (volume->vol_name) {
 338                 kfree(volume->vol_name, M_HAMMER);
 339                 volume->vol_name = NULL;
 340         }
 341         if (volume->devvp) {
 342                 vrele(volume->devvp);
 343                 volume->devvp = NULL;
 344         }
 345         --hammer_count_volumes;
 346         kfree(volume, M_HAMMER);
 347 }
 348
 349 /*
 350  * Get a HAMMER volume.  The volume must already exist.
 351  */
 352 hammer_volume_t
 353 hammer_get_volume(struct hammer_mount *hmp, int32_t vol_no, int *errorp)
 354 {
 355         struct hammer_volume *volume;
 356
 357         /*
 358          * Locate the volume structure
 359          */
 360         volume = RB_LOOKUP(hammer_vol_rb_tree, &hmp->rb_vols_root, vol_no);
 361         if (volume == NULL) {
 362                 *errorp = ENOENT;
 363                 return(NULL);
 364         }
 365         hammer_ref(&volume->io.lock);
 366
 367         /*
 368          * Deal with on-disk info
 369          */
 370         if (volume->ondisk == NULL || volume->io.loading) {
 371                 *errorp = hammer_load_volume(volume);
 372                 if (*errorp) {
 373                         hammer_rel_volume(volume, 1);
 374                         volume = NULL;
 375                 }
 376         } else {
 377                 *errorp = 0;
 378         }
 379         return(volume);
 380 }
 381
 382 int
 383 hammer_ref_volume(hammer_volume_t volume)
 384 {
 385         int error;
 386
 387         hammer_ref(&volume->io.lock);
 388
 389         /*
 390          * Deal with on-disk info
 391          */
 392         if (volume->ondisk == NULL || volume->io.loading) {
 393                 error = hammer_load_volume(volume);
 394                 if (error)
 395                         hammer_rel_volume(volume, 1);
 396         } else {
 397                 error = 0;
 398         }
 399         return (error);
 400 }
 401
 402 hammer_volume_t
 403 hammer_get_root_volume(struct hammer_mount *hmp, int *errorp)
 404 {
 405         hammer_volume_t volume;
 406
 407         volume = hmp->rootvol;
 408         KKASSERT(volume != NULL);
 409         hammer_ref(&volume->io.lock);
 410
 411         /*
 412          * Deal with on-disk info
 413          */
 414         if (volume->ondisk == NULL || volume->io.loading) {
 415                 *errorp = hammer_load_volume(volume);
 416                 if (*errorp) {
 417                         hammer_rel_volume(volume, 1);
 418                         volume = NULL;
 419                 }
 420         } else {
 421                 *errorp = 0;
 422         }
 423         return (volume);
 424 }
 425
 426 /*
 427  * Load a volume's on-disk information.  The volume must be referenced and
 428  * not locked.  We temporarily acquire an exclusive lock to interlock
 429  * against releases or multiple get's.
 430  */
 431 static int
 432 hammer_load_volume(hammer_volume_t volume)
 433 {
 434         int error;
 435
 436         ++volume->io.loading;
 437         hammer_lock_ex(&volume->io.lock);
 438
 439         if (volume->ondisk == NULL) {
 440                 error = hammer_io_read(volume->devvp, &volume->io);
 441                 if (error == 0)
 442                         volume->ondisk = (void *)volume->io.bp->b_data;
 443         } else {
 444                 error = 0;
 445         }
 446         --volume->io.loading;
 447         hammer_unlock(&volume->io.lock);
 448         return(error);
 449 }
 450
 451 /*
 452  * Release a volume.  Call hammer_io_release on the last reference.  We have
 453  * to acquire an exclusive lock to interlock against volume->ondisk tests
 454  * in hammer_load_volume(), and hammer_io_release() also expects an exclusive
 455  * lock to be held.
 456  *
 457  * Volumes are not unloaded from memory during normal operation.
 458  */
 459 void
 460 hammer_rel_volume(hammer_volume_t volume, int flush)
 461 {
 462         if (flush)
 463                 volume->io.flush = 1;
 464         crit_enter();
 465         if (volume->io.lock.refs == 1) {
 466                 ++volume->io.loading;
 467                 hammer_lock_ex(&volume->io.lock);
 468                 if (volume->io.lock.refs == 1) {
 469                         volume->ondisk = NULL;
 470                         hammer_io_release(&volume->io);
 471                 }
 472                 --volume->io.loading;
 473                 hammer_unlock(&volume->io.lock);
 474         }
 475         hammer_unref(&volume->io.lock);
 476         crit_exit();
 477 }
 478
 479 /************************************************************************
 480  *                              BUFFERS                                 *
 481  ************************************************************************
 482  *
 483  * Manage buffers.  Currently all blockmap-backed zones are translated
 484  * to zone-2 buffer offsets.
 485  */
 486 hammer_buffer_t
 487 hammer_get_buffer(hammer_mount_t hmp, hammer_off_t buf_offset,
 488                   int isnew, int *errorp)
 489 {
 490         hammer_buffer_t buffer;
 491         hammer_volume_t volume;
 492         hammer_off_t    zoneX_offset;
 493         int vol_no;
 494         int zone;
 495
 496         zoneX_offset = buf_offset;
 497         zone = HAMMER_ZONE_DECODE(buf_offset);
 498         if (zone >= HAMMER_ZONE_BTREE_INDEX) {
 499                 buf_offset = hammer_blockmap_lookup(hmp, buf_offset, errorp);
 500                 KKASSERT(*errorp == 0);
 501         } else if (zone == HAMMER_ZONE_UNDO_INDEX) {
 502                 buf_offset = hammer_undo_lookup(hmp, buf_offset, errorp);
 503                 KKASSERT(*errorp == 0);
 504         }
 505         buf_offset &= ~HAMMER_BUFMASK64;
 506         KKASSERT((buf_offset & HAMMER_ZONE_RAW_BUFFER) ==
 507                  HAMMER_ZONE_RAW_BUFFER);
 508         vol_no = HAMMER_VOL_DECODE(buf_offset);
 509         volume = hammer_get_volume(hmp, vol_no, errorp);
 510         if (volume == NULL)
 511                 return(NULL);
 512
 513         /*
 514          * NOTE: buf_offset and maxbuf_off are both full offset
 515          * specifications.
 516          */
 517         KKASSERT(buf_offset < volume->maxbuf_off);
 518
 519         /*
 520          * Locate and lock the buffer structure, creating one if necessary.
 521          */
 522 again:
 523         buffer = RB_LOOKUP(hammer_buf_rb_tree, &volume->rb_bufs_root,
 524                            buf_offset);
 525         if (buffer == NULL) {
 526                 ++hammer_count_buffers;
 527                 buffer = kmalloc(sizeof(*buffer), M_HAMMER, M_WAITOK|M_ZERO);
 528                 buffer->zone2_offset = buf_offset;
 529                 buffer->volume = volume;
 530                 hammer_io_init(&buffer->io, HAMMER_STRUCTURE_BUFFER);
 531                 buffer->io.offset = volume->ondisk->vol_buf_beg +
 532                                     (buf_offset & HAMMER_OFF_SHORT_MASK);
 533                 TAILQ_INIT(&buffer->clist);
 534                 hammer_ref(&buffer->io.lock);
 535
 536                 /*
 537                  * Insert the buffer into the RB tree and handle late
 538                  * collisions.
 539                  */
 540                 if (RB_INSERT(hammer_buf_rb_tree, &volume->rb_bufs_root, buffer)) {
 541                         hammer_unref(&buffer->io.lock);
 542                         --hammer_count_buffers;
 543                         kfree(buffer, M_HAMMER);
 544                         goto again;
 545                 }
 546                 hammer_ref(&volume->io.lock);
 547         } else {
 548                 hammer_ref(&buffer->io.lock);
 549         }
 550
 551         /*
 552          * Cache the blockmap translation
 553          */
 554         if ((zoneX_offset & HAMMER_ZONE_RAW_BUFFER) != HAMMER_ZONE_RAW_BUFFER)
 555                 buffer->zoneX_offset = zoneX_offset;
 556
 557         /*
 558          * Deal with on-disk info
 559          */
 560         if (buffer->ondisk == NULL || buffer->io.loading) {
 561                 *errorp = hammer_load_buffer(buffer, isnew);
 562                 if (*errorp) {
 563                         hammer_rel_buffer(buffer, 1);
 564                         buffer = NULL;
 565                 }
 566         } else {
 567                 *errorp = 0;
 568         }
 569         hammer_rel_volume(volume, 0);
 570         return(buffer);
 571 }
 572
 573 static int
 574 hammer_load_buffer(hammer_buffer_t buffer, int isnew)
 575 {
 576         hammer_volume_t volume;
 577         int error;
 578
 579         /*
 580          * Load the buffer's on-disk info
 581          */
 582         volume = buffer->volume;
 583         ++buffer->io.loading;
 584         hammer_lock_ex(&buffer->io.lock);
 585
 586         if (buffer->ondisk == NULL) {
 587                 if (isnew) {
 588                         error = hammer_io_new(volume->devvp, &buffer->io);
 589                 } else {
 590                         error = hammer_io_read(volume->devvp, &buffer->io);
 591                 }
 592                 if (error == 0)
 593                         buffer->ondisk = (void *)buffer->io.bp->b_data;
 594         } else if (isnew) {
 595                 error = hammer_io_new(volume->devvp, &buffer->io);
 596         } else {
 597                 error = 0;
 598         }
 599         if (error == 0 && isnew) {
 600                 hammer_modify_buffer(NULL, buffer, NULL, 0);
 601                 /* additional initialization goes here */
 602         }
 603         --buffer->io.loading;
 604         hammer_unlock(&buffer->io.lock);
 605         return (error);
 606 }
 607
 608 /*
 609  * NOTE: Called from RB_SCAN, must return >= 0 for scan to continue.
 610  */
 611 int
 612 hammer_unload_buffer(hammer_buffer_t buffer, void *data __unused)
 613 {
 614         hammer_ref(&buffer->io.lock);
 615         hammer_flush_buffer_nodes(buffer);
 616         KKASSERT(buffer->io.lock.refs == 1);
 617         hammer_rel_buffer(buffer, 2);
 618         return(0);
 619 }
 620
 621 /*
 622  * Reference a buffer that is either already referenced or via a specially
 623  * handled pointer (aka cursor->buffer).
 624  */
 625 int
 626 hammer_ref_buffer(hammer_buffer_t buffer)
 627 {
 628         int error;
 629
 630         hammer_ref(&buffer->io.lock);
 631         if (buffer->ondisk == NULL || buffer->io.loading) {
 632                 error = hammer_load_buffer(buffer, 0);
 633                 if (error) {
 634                         hammer_rel_buffer(buffer, 1);
 635                         /*
 636                          * NOTE: buffer pointer can become stale after
 637                          * the above release.
 638                          */
 639                 }
 640         } else {
 641                 error = 0;
 642         }
 643         return(error);
 644 }
 645
 646 /*
 647  * Release a buffer.  We have to deal with several places where
 648  * another thread can ref the buffer.
 649  *
 650  * Only destroy the structure itself if the related buffer cache buffer
 651  * was disassociated from it.  This ties the management of the structure
 652  * to the buffer cache subsystem.  buffer->ondisk determines whether the
 653  * embedded io is referenced or not.
 654  */
 655 void
 656 hammer_rel_buffer(hammer_buffer_t buffer, int flush)
 657 {
 658         hammer_volume_t volume;
 659         int freeme = 0;
 660
 661         if (flush)
 662                 buffer->io.flush = 1;
 663         crit_enter();
 664         if (buffer->io.lock.refs == 1) {
 665                 ++buffer->io.loading;   /* force interlock check */
 666                 hammer_lock_ex(&buffer->io.lock);
 667                 if (buffer->io.lock.refs == 1) {
 668                         hammer_io_release(&buffer->io);
 669                         hammer_flush_buffer_nodes(buffer);
 670                         KKASSERT(TAILQ_EMPTY(&buffer->clist));
 671
 672                         if (buffer->io.bp == NULL &&
 673                             buffer->io.lock.refs == 1) {
 674                                 /*
 675                                  * Final cleanup
 676                                  */
 677                                 volume = buffer->volume;
 678                                 RB_REMOVE(hammer_buf_rb_tree,
 679                                           &volume->rb_bufs_root, buffer);
 680                                 buffer->volume = NULL; /* sanity */
 681                                 hammer_rel_volume(volume, 0);
 682                                 freeme = 1;
 683                         }
 684                 }
 685                 --buffer->io.loading;
 686                 hammer_unlock(&buffer->io.lock);
 687         }
 688         hammer_unref(&buffer->io.lock);
 689         crit_exit();
 690         if (freeme) {
 691                 --hammer_count_buffers;
 692                 kfree(buffer, M_HAMMER);
 693         }
 694 }
 695
 696 /*
 697  * Remove the zoneX translation cache for a buffer given its zone-2 offset.
 698  */
 699 void
 700 hammer_uncache_buffer(hammer_mount_t hmp, hammer_off_t buf_offset)
 701 {
 702         hammer_volume_t volume;
 703         hammer_buffer_t buffer;
 704         int vol_no;
 705         int error;
 706
 707         buf_offset &= ~HAMMER_BUFMASK64;
 708         KKASSERT((buf_offset & HAMMER_ZONE_RAW_BUFFER) ==
 709                  HAMMER_ZONE_RAW_BUFFER);
 710         vol_no = HAMMER_VOL_DECODE(buf_offset);
 711         volume = hammer_get_volume(hmp, vol_no, &error);
 712         KKASSERT(volume != 0);
 713         KKASSERT(buf_offset < volume->maxbuf_off);
 714
 715         buffer = RB_LOOKUP(hammer_buf_rb_tree, &volume->rb_bufs_root,
 716                            buf_offset);
 717         if (buffer)
 718                 buffer->zoneX_offset = 0;
 719         hammer_rel_volume(volume, 0);
 720 }
 721
 722 /*
 723  * Access the filesystem buffer containing the specified hammer offset.
 724  * buf_offset is a conglomeration of the volume number and vol_buf_beg
 725  * relative buffer offset.  It must also have bit 55 set to be valid.
 726  * (see hammer_off_t in hammer_disk.h).
 727  *
 728  * Any prior buffer in *bufferp will be released and replaced by the
 729  * requested buffer.
 730  */
 731 void *
 732 hammer_bread(hammer_mount_t hmp, hammer_off_t buf_offset, int *errorp,
 733              struct hammer_buffer **bufferp)
 734 {
 735         hammer_buffer_t buffer;
 736         int32_t xoff = (int32_t)buf_offset & HAMMER_BUFMASK;
 737
 738         buf_offset &= ~HAMMER_BUFMASK64;
 739         KKASSERT((buf_offset & HAMMER_OFF_ZONE_MASK) != 0);
 740
 741         buffer = *bufferp;
 742         if (buffer == NULL || (buffer->zone2_offset != buf_offset &&
 743                                buffer->zoneX_offset != buf_offset)) {
 744                 if (buffer)
 745                         hammer_rel_buffer(buffer, 0);
 746                 buffer = hammer_get_buffer(hmp, buf_offset, 0, errorp);
 747                 *bufferp = buffer;
 748         } else {
 749                 *errorp = 0;
 750         }
 751
 752         /*
 753          * Return a pointer to the buffer data.
 754          */
 755         if (buffer == NULL)
 756                 return(NULL);
 757         else
 758                 return((char *)buffer->ondisk + xoff);
 759 }
 760
 761 /*
 762  * Access the filesystem buffer containing the specified hammer offset.
 763  * No disk read operation occurs.  The result buffer may contain garbage.
 764  *
 765  * Any prior buffer in *bufferp will be released and replaced by the
 766  * requested buffer.
 767  */
 768 void *
 769 hammer_bnew(hammer_mount_t hmp, hammer_off_t buf_offset, int *errorp,
 770              struct hammer_buffer **bufferp)
 771 {
 772         hammer_buffer_t buffer;
 773         int32_t xoff = (int32_t)buf_offset & HAMMER_BUFMASK;
 774
 775         buf_offset &= ~HAMMER_BUFMASK64;
 776
 777         buffer = *bufferp;
 778         if (buffer == NULL || (buffer->zone2_offset != buf_offset &&
 779                                buffer->zoneX_offset != buf_offset)) {
 780                 if (buffer)
 781                         hammer_rel_buffer(buffer, 0);
 782                 buffer = hammer_get_buffer(hmp, buf_offset, 1, errorp);
 783                 *bufferp = buffer;
 784         } else {
 785                 *errorp = 0;
 786         }
 787
 788         /*
 789          * Return a pointer to the buffer data.
 790          */
 791         if (buffer == NULL)
 792                 return(NULL);
 793         else
 794                 return((char *)buffer->ondisk + xoff);
 795 }
 796
 797 /************************************************************************
 798  *                              NODES                                   *
 799  ************************************************************************
 800  *
 801  * Manage B-Tree nodes.  B-Tree nodes represent the primary indexing
 802  * method used by the HAMMER filesystem.
 803  *
 804  * Unlike other HAMMER structures, a hammer_node can be PASSIVELY
 805  * associated with its buffer, and will only referenced the buffer while
 806  * the node itself is referenced.
 807  *
 808  * A hammer_node can also be passively associated with other HAMMER
 809  * structures, such as inodes, while retaining 0 references.  These
 810  * associations can be cleared backwards using a pointer-to-pointer in
 811  * the hammer_node.
 812  *
 813  * This allows the HAMMER implementation to cache hammer_nodes long-term
 814  * and short-cut a great deal of the infrastructure's complexity.  In
 815  * most cases a cached node can be reacquired without having to dip into
 816  * either the buffer or cluster management code.
 817  *
 818  * The caller must pass a referenced cluster on call and will retain
 819  * ownership of the reference on return.  The node will acquire its own
 820  * additional references, if necessary.
 821  */
 822 hammer_node_t
 823 hammer_get_node(hammer_mount_t hmp, hammer_off_t node_offset, int *errorp)
 824 {
 825         hammer_node_t node;
 826
 827         KKASSERT((node_offset & HAMMER_OFF_ZONE_MASK) == HAMMER_ZONE_BTREE);
 828
 829         /*
 830          * Locate the structure, allocating one if necessary.
 831          */
 832 again:
 833         node = RB_LOOKUP(hammer_nod_rb_tree, &hmp->rb_nods_root, node_offset);
 834         if (node == NULL) {
 835                 ++hammer_count_nodes;
 836                 node = kmalloc(sizeof(*node), M_HAMMER, M_WAITOK|M_ZERO);
 837                 node->node_offset = node_offset;
 838                 node->hmp = hmp;
 839                 if (RB_INSERT(hammer_nod_rb_tree, &hmp->rb_nods_root, node)) {
 840                         --hammer_count_nodes;
 841                         kfree(node, M_HAMMER);
 842                         goto again;
 843                 }
 844         }
 845         hammer_ref(&node->lock);
 846         if (node->ondisk)
 847                 *errorp = 0;
 848         else
 849                 *errorp = hammer_load_node(node);
 850         if (*errorp) {
 851                 hammer_rel_node(node);
 852                 node = NULL;
 853         }
 854         return(node);
 855 }
 856
 857 /*
 858  * Reference an already-referenced node.
 859  */
 860 void
 861 hammer_ref_node(hammer_node_t node)
 862 {
 863         KKASSERT(node->lock.refs > 0 && node->ondisk != NULL);
 864         hammer_ref(&node->lock);
 865 }
 866
 867 /*
 868  * Load a node's on-disk data reference.
 869  */
 870 static int
 871 hammer_load_node(hammer_node_t node)
 872 {
 873         hammer_buffer_t buffer;
 874         int error;
 875
 876         error = 0;
 877         ++node->loading;
 878         hammer_lock_ex(&node->lock);
 879         if (node->ondisk == NULL) {
 880                 /*
 881                  * This is a little confusing but the jist is that
 882                  * node->buffer determines whether the node is on
 883                  * the buffer's clist and node->ondisk determines
 884                  * whether the buffer is referenced.
 885                  *
 886                  * We could be racing a buffer release, in which case
 887                  * node->buffer may become NULL while we are blocked
 888                  * referencing the buffer.
 889                  */
 890                 if ((buffer = node->buffer) != NULL) {
 891                         error = hammer_ref_buffer(buffer);
 892                         if (error == 0 && node->buffer == NULL) {
 893                                 TAILQ_INSERT_TAIL(&buffer->clist,
 894                                                   node, entry);
 895                                 node->buffer = buffer;
 896                         }
 897                 } else {
 898                         buffer = hammer_get_buffer(node->hmp,
 899                                                    node->node_offset, 0,
 900                                                    &error);
 901                         if (buffer) {
 902                                 KKASSERT(error == 0);
 903                                 TAILQ_INSERT_TAIL(&buffer->clist,
 904                                                   node, entry);
 905                                 node->buffer = buffer;
 906                         }
 907                 }
 908                 if (error == 0) {
 909                         node->ondisk = (void *)((char *)buffer->ondisk +
 910                                (node->node_offset & HAMMER_BUFMASK));
 911                 }
 912         }
 913         --node->loading;
 914         hammer_unlock(&node->lock);
 915         return (error);
 916 }
 917
 918 /*
 919  * Safely reference a node, interlock against flushes via the IO subsystem.
 920  */
 921 hammer_node_t
 922 hammer_ref_node_safe(struct hammer_mount *hmp, struct hammer_node **cache,
 923                      int *errorp)
 924 {
 925         hammer_node_t node;
 926
 927         node = *cache;
 928         if (node != NULL) {
 929                 hammer_ref(&node->lock);
 930                 if (node->ondisk)
 931                         *errorp = 0;
 932                 else
 933                         *errorp = hammer_load_node(node);
 934                 if (*errorp) {
 935                         hammer_rel_node(node);
 936                         node = NULL;
 937                 }
 938         } else {
 939                 *errorp = ENOENT;
 940         }
 941         return(node);
 942 }
 943
 944 /*
 945  * Release a hammer_node.  On the last release the node dereferences
 946  * its underlying buffer and may or may not be destroyed.
 947  */
 948 void
 949 hammer_rel_node(hammer_node_t node)
 950 {
 951         hammer_buffer_t buffer;
 952
 953         /*
 954          * If this isn't the last ref just decrement the ref count and
 955          * return.
 956          */
 957         if (node->lock.refs > 1) {
 958                 hammer_unref(&node->lock);
 959                 return;
 960         }
 961
 962         /*
 963          * If there is no ondisk info or no buffer the node failed to load,
 964          * remove the last reference and destroy the node.
 965          */
 966         if (node->ondisk == NULL) {
 967                 hammer_unref(&node->lock);
 968                 hammer_flush_node(node);
 969                 /* node is stale now */
 970                 return;
 971         }
 972
 973         /*
 974          * Do final cleanups and then either destroy the node and leave it
 975          * passively cached.  The buffer reference is removed regardless.
 976          */
 977         buffer = node->buffer;
 978         node->ondisk = NULL;
 979
 980         if ((node->flags & HAMMER_NODE_FLUSH) == 0) {
 981                 hammer_unref(&node->lock);
 982                 hammer_rel_buffer(buffer, 0);
 983                 return;
 984         }
 985
 986         /*
 987          * Destroy the node.
 988          */
 989         hammer_unref(&node->lock);
 990         hammer_flush_node(node);
 991         /* node is stale */
 992         hammer_rel_buffer(buffer, 0);
 993 }
 994
 995 /*
 996  *
 997  *
 998  */
 999 void
1000 hammer_delete_node(hammer_transaction_t trans, hammer_node_t node)
1001 {
1002         node->flags |= HAMMER_NODE_DELETED;
1003         hammer_blockmap_free(trans, node->node_offset, sizeof(*node->ondisk));
1004 }
1005
1006 /*
1007  * Passively cache a referenced hammer_node in *cache.  The caller may
1008  * release the node on return.
1009  */
1010 void
1011 hammer_cache_node(hammer_node_t node, struct hammer_node **cache)
1012 {
1013         hammer_node_t old;
1014
1015         /*
1016          * If the node is being deleted, don't cache it!
1017          */
1018         if (node->flags & HAMMER_NODE_DELETED)
1019                 return;
1020
1021         /*
1022          * Cache the node.  If we previously cached a different node we
1023          * have to give HAMMER a chance to destroy it.
1024          */
1025 again:
1026         if (node->cache1 != cache) {
1027                 if (node->cache2 != cache) {
1028                         if ((old = *cache) != NULL) {
1029                                 KKASSERT(node->lock.refs != 0);
1030                                 hammer_uncache_node(cache);
1031                                 goto again;
1032                         }
1033                         if (node->cache2)
1034                                 *node->cache2 = NULL;
1035                         node->cache2 = node->cache1;
1036                         node->cache1 = cache;
1037                         *cache = node;
1038                 } else {
1039                         struct hammer_node **tmp;
1040                         tmp = node->cache1;
1041                         node->cache1 = node->cache2;
1042                         node->cache2 = tmp;
1043                 }
1044         }
1045 }
1046
1047 void
1048 hammer_uncache_node(struct hammer_node **cache)
1049 {
1050         hammer_node_t node;
1051
1052         if ((node = *cache) != NULL) {
1053                 *cache = NULL;
1054                 if (node->cache1 == cache) {
1055                         node->cache1 = node->cache2;
1056                         node->cache2 = NULL;
1057                 } else if (node->cache2 == cache) {
1058                         node->cache2 = NULL;
1059                 } else {
1060                         panic("hammer_uncache_node: missing cache linkage");
1061                 }
1062                 if (node->cache1 == NULL && node->cache2 == NULL)
1063                         hammer_flush_node(node);
1064         }
1065 }
1066
1067 /*
1068  * Remove a node's cache references and destroy the node if it has no
1069  * other references or backing store.
1070  */
1071 void
1072 hammer_flush_node(hammer_node_t node)
1073 {
1074         hammer_buffer_t buffer;
1075
1076         if (node->cache1)
1077                 *node->cache1 = NULL;
1078         if (node->cache2)
1079                 *node->cache2 = NULL;
1080         if (node->lock.refs == 0 && node->ondisk == NULL) {
1081                 RB_REMOVE(hammer_nod_rb_tree, &node->hmp->rb_nods_root, node);
1082                 if ((buffer = node->buffer) != NULL) {
1083                         node->buffer = NULL;
1084                         TAILQ_REMOVE(&buffer->clist, node, entry);
1085                         /* buffer is unreferenced because ondisk is NULL */
1086                 }
1087                 --hammer_count_nodes;
1088                 kfree(node, M_HAMMER);
1089         }
1090 }
1091
1092 /*
1093  * Flush passively cached B-Tree nodes associated with this buffer.
1094  * This is only called when the buffer is about to be destroyed, so
1095  * none of the nodes should have any references.  The buffer is locked.
1096  *
1097  * We may be interlocked with the buffer.
1098  */
1099 void
1100 hammer_flush_buffer_nodes(hammer_buffer_t buffer)
1101 {
1102         hammer_node_t node;
1103
1104         while ((node = TAILQ_FIRST(&buffer->clist)) != NULL) {
1105                 KKASSERT(node->ondisk == NULL);
1106
1107                 if (node->lock.refs == 0) {
1108                         hammer_ref(&node->lock);
1109                         node->flags |= HAMMER_NODE_FLUSH;
1110                         hammer_rel_node(node);
1111                 } else {
1112                         KKASSERT(node->loading != 0);
1113                         KKASSERT(node->buffer != NULL);
1114                         buffer = node->buffer;
1115                         node->buffer = NULL;
1116                         TAILQ_REMOVE(&buffer->clist, node, entry);
1117                         /* buffer is unreferenced because ondisk is NULL */
1118                 }
1119         }
1120 }
1121
1122
1123 /************************************************************************
1124  *                              ALLOCATORS                              *
1125  ************************************************************************/
1126
1127 /*
1128  * Allocate a B-Tree node.
1129  */
1130 hammer_node_t
1131 hammer_alloc_btree(hammer_transaction_t trans, int *errorp)
1132 {
1133         hammer_buffer_t buffer = NULL;
1134         hammer_node_t node = NULL;
1135         hammer_off_t node_offset;
1136
1137         node_offset = hammer_blockmap_alloc(trans, HAMMER_ZONE_BTREE_INDEX,
1138                                             sizeof(struct hammer_node_ondisk),
1139                                             errorp);
1140         if (*errorp == 0) {
1141                 node = hammer_get_node(trans->hmp, node_offset, errorp);
1142                 hammer_modify_node_noundo(trans, node);
1143                 bzero(node->ondisk, sizeof(*node->ondisk));
1144         }
1145         if (buffer)
1146                 hammer_rel_buffer(buffer, 0);
1147         return(node);
1148 }
1149
1150 /*
1151  * The returned buffers are already appropriately marked as being modified.
1152  * If the caller marks them again unnecessary undo records may be generated.
1153  *
1154  * In-band data is indicated by data_bufferp == NULL.  Pass a data_len of 0
1155  * for zero-fill (caller modifies data_len afterwords).
1156  */
1157 void *
1158 hammer_alloc_record(hammer_transaction_t trans,
1159                     hammer_off_t *rec_offp, u_int16_t rec_type,
1160                     struct hammer_buffer **rec_bufferp,
1161                     int32_t data_len, void **datap,
1162                     struct hammer_buffer **data_bufferp, int *errorp)
1163 {
1164         hammer_record_ondisk_t rec;
1165         hammer_off_t rec_offset;
1166         hammer_off_t data_offset;
1167         int32_t reclen;
1168
1169         if (datap)
1170                 *datap = NULL;
1171
1172         /*
1173          * Allocate the record
1174          */
1175         rec_offset = hammer_blockmap_alloc(trans, HAMMER_ZONE_RECORD_INDEX,
1176                                            HAMMER_RECORD_SIZE, errorp);
1177         if (*errorp)
1178                 return(NULL);
1179
1180         /*
1181          * Allocate data
1182          */
1183         if (data_len) {
1184                 if (data_bufferp == NULL) {
1185                         switch(rec_type) {
1186                         case HAMMER_RECTYPE_DATA:
1187                                 reclen = offsetof(struct hammer_data_record,
1188                                                   data[0]);
1189                                 break;
1190                         case HAMMER_RECTYPE_DIRENTRY:
1191                                 reclen = offsetof(struct hammer_entry_record,
1192                                                   name[0]);
1193                                 break;
1194                         default:
1195                                 panic("hammer_alloc_record: illegal "
1196                                       "in-band data");
1197                                 /* NOT REACHED */
1198                                 reclen = 0;
1199                                 break;
1200                         }
1201                         KKASSERT(reclen + data_len <= HAMMER_RECORD_SIZE);
1202                         data_offset = rec_offset + reclen;
1203                 } else if (data_len < HAMMER_BUFSIZE) {
1204                         data_offset = hammer_blockmap_alloc(trans,
1205                                                 HAMMER_ZONE_SMALL_DATA_INDEX,
1206                                                 data_len, errorp);
1207                 } else {
1208                         data_offset = hammer_blockmap_alloc(trans,
1209                                                 HAMMER_ZONE_LARGE_DATA_INDEX,
1210                                                 data_len, errorp);
1211                 }
1212         } else {
1213                 data_offset = 0;
1214         }
1215         if (*errorp) {
1216                 hammer_blockmap_free(trans, rec_offset, HAMMER_RECORD_SIZE);
1217                 return(NULL);
1218         }
1219
1220         /*
1221          * Basic return values.
1222          */
1223         *rec_offp = rec_offset;
1224         rec = hammer_bread(trans->hmp, rec_offset, errorp, rec_bufferp);
1225         hammer_modify_buffer(trans, *rec_bufferp, NULL, 0);
1226         bzero(rec, sizeof(*rec));
1227         KKASSERT(*errorp == 0);
1228         rec->base.data_off = data_offset;
1229         rec->base.data_len = data_len;
1230
1231         if (data_bufferp) {
1232                 if (data_len) {
1233                         *datap = hammer_bread(trans->hmp, data_offset, errorp,
1234                                               data_bufferp);
1235                         KKASSERT(*errorp == 0);
1236                         hammer_modify_buffer(trans, *data_bufferp, NULL, 0);
1237                 } else {
1238                         *datap = NULL;
1239                 }
1240         } else if (data_len) {
1241                 KKASSERT(data_offset + data_len - rec_offset <=
1242                          HAMMER_RECORD_SIZE);
1243                 if (datap) {
1244                         *datap = (void *)((char *)rec +
1245                                           (int32_t)(data_offset - rec_offset));
1246                 }
1247         } else {
1248                 KKASSERT(datap == NULL);
1249         }
1250         KKASSERT(*errorp == 0);
1251         return(rec);
1252 }
1253
1254 void *
1255 hammer_alloc_data(hammer_transaction_t trans, int32_t data_len,
1256                   hammer_off_t *data_offsetp,
1257                   struct hammer_buffer **data_bufferp, int *errorp)
1258 {
1259         void *data;
1260
1261         /*
1262          * Allocate data
1263          */
1264         if (data_len) {
1265                 if (data_len < HAMMER_BUFSIZE) {
1266                         *data_offsetp = hammer_blockmap_alloc(trans,
1267                                                 HAMMER_ZONE_SMALL_DATA_INDEX,
1268                                                 data_len, errorp);
1269                 } else {
1270                         *data_offsetp = hammer_blockmap_alloc(trans,
1271                                                 HAMMER_ZONE_LARGE_DATA_INDEX,
1272                                                 data_len, errorp);
1273                 }
1274         } else {
1275                 *data_offsetp = 0;
1276         }
1277         if (*errorp == 0 && data_bufferp) {
1278                 if (data_len) {
1279                         data = hammer_bread(trans->hmp, *data_offsetp, errorp,
1280                                             data_bufferp);
1281                         KKASSERT(*errorp == 0);
1282                         hammer_modify_buffer(trans, *data_bufferp, NULL, 0);
1283                 } else {
1284                         data = NULL;
1285                 }
1286         } else {
1287                 data = NULL;
1288         }
1289         KKASSERT(*errorp == 0);
1290         return(data);
1291 }
1292
1293
1294 /*
1295  * Sync dirty buffers to the media
1296  */
1297
1298 static int hammer_sync_scan1(struct mount *mp, struct vnode *vp, void *data);
1299 static int hammer_sync_scan2(struct mount *mp, struct vnode *vp, void *data);
1300
1301 int
1302 hammer_sync_hmp(hammer_mount_t hmp, int waitfor)
1303 {
1304         struct hammer_sync_info info;
1305
1306         info.error = 0;
1307         info.waitfor = waitfor;
1308
1309         vmntvnodescan(hmp->mp, VMSC_GETVP|VMSC_NOWAIT,
1310                       hammer_sync_scan1, hammer_sync_scan2, &info);
1311
1312         RB_SCAN(hammer_vol_rb_tree, &hmp->rb_vols_root, NULL,
1313                 hammer_sync_volume, &info);
1314         return(info.error);
1315 }
1316
1317 static int
1318 hammer_sync_scan1(struct mount *mp, struct vnode *vp, void *data)
1319 {
1320         struct hammer_inode *ip;
1321
1322         ip = VTOI(vp);
1323         if (vp->v_type == VNON || ip == NULL ||
1324             ((ip->flags & HAMMER_INODE_MODMASK) == 0 &&
1325              RB_EMPTY(&vp->v_rbdirty_tree))) {
1326                 return(-1);
1327         }
1328         return(0);
1329 }
1330
1331 static int
1332 hammer_sync_scan2(struct mount *mp, struct vnode *vp, void *data)
1333 {
1334         struct hammer_sync_info *info = data;
1335         struct hammer_inode *ip;
1336         int error;
1337
1338         ip = VTOI(vp);
1339         if (vp->v_type == VNON || vp->v_type == VBAD ||
1340             ((ip->flags & HAMMER_INODE_MODMASK) == 0 &&
1341              RB_EMPTY(&vp->v_rbdirty_tree))) {
1342                 return(0);
1343         }
1344         error = VOP_FSYNC(vp, info->waitfor);
1345         if (error)
1346                 info->error = error;
1347         return(0);
1348 }
1349
1350 int
1351 hammer_sync_volume(hammer_volume_t volume, void *data)
1352 {
1353         struct hammer_sync_info *info = data;
1354
1355         hammer_ref(&volume->io.lock);
1356         RB_SCAN(hammer_buf_rb_tree, &volume->rb_bufs_root, NULL,
1357                 hammer_sync_buffer, info);
1358         hammer_rel_volume(volume, 1);
1359         return(0);
1360 }
1361
1362 int
1363 hammer_sync_buffer(hammer_buffer_t buffer, void *data __unused)
1364 {
1365         hammer_ref(&buffer->io.lock);
1366         hammer_rel_buffer(buffer, 1);
1367         return(0);
1368 }
1369