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 1.76 2008/08/29 20:19:08 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_transaction_t trans,
  52                                 hammer_node_t node, int isnew);
  53
  54 static int
  55 hammer_vol_rb_compare(hammer_volume_t vol1, hammer_volume_t vol2)
  56 {
  57         if (vol1->vol_no < vol2->vol_no)
  58                 return(-1);
  59         if (vol1->vol_no > vol2->vol_no)
  60                 return(1);
  61         return(0);
  62 }
  63
  64 /*
  65  * hammer_buffer structures are indexed via their zoneX_offset, not
  66  * their zone2_offset.
  67  */
  68 static int
  69 hammer_buf_rb_compare(hammer_buffer_t buf1, hammer_buffer_t buf2)
  70 {
  71         if (buf1->zoneX_offset < buf2->zoneX_offset)
  72                 return(-1);
  73         if (buf1->zoneX_offset > buf2->zoneX_offset)
  74                 return(1);
  75         return(0);
  76 }
  77
  78 static int
  79 hammer_nod_rb_compare(hammer_node_t node1, hammer_node_t node2)
  80 {
  81         if (node1->node_offset < node2->node_offset)
  82                 return(-1);
  83         if (node1->node_offset > node2->node_offset)
  84                 return(1);
  85         return(0);
  86 }
  87
  88 RB_GENERATE2(hammer_vol_rb_tree, hammer_volume, rb_node,
  89              hammer_vol_rb_compare, int32_t, vol_no);
  90 RB_GENERATE2(hammer_buf_rb_tree, hammer_buffer, rb_node,
  91              hammer_buf_rb_compare, hammer_off_t, zoneX_offset);
  92 RB_GENERATE2(hammer_nod_rb_tree, hammer_node, rb_node,
  93              hammer_nod_rb_compare, hammer_off_t, node_offset);
  94
  95 /************************************************************************
  96  *                              VOLUMES                                 *
  97  ************************************************************************
  98  *
  99  * Load a HAMMER volume by name.  Returns 0 on success or a positive error
 100  * code on failure.  Volumes must be loaded at mount time, get_volume() will
 101  * not load a new volume.
 102  *
 103  * Calls made to hammer_load_volume() or single-threaded
 104  */
 105 int
 106 hammer_install_volume(struct hammer_mount *hmp, const char *volname,
 107                       struct vnode *devvp)
 108 {
 109         struct mount *mp;
 110         hammer_volume_t volume;
 111         struct hammer_volume_ondisk *ondisk;
 112         struct nlookupdata nd;
 113         struct buf *bp = NULL;
 114         int error;
 115         int ronly;
 116         int setmp = 0;
 117
 118         mp = hmp->mp;
 119         ronly = ((mp->mnt_flag & MNT_RDONLY) ? 1 : 0);
 120
 121         /*
 122          * Allocate a volume structure
 123          */
 124         ++hammer_count_volumes;
 125         volume = kmalloc(sizeof(*volume), hmp->m_misc, M_WAITOK|M_ZERO);
 126         volume->vol_name = kstrdup(volname, hmp->m_misc);
 127         volume->io.hmp = hmp;   /* bootstrap */
 128         hammer_io_init(&volume->io, volume, HAMMER_STRUCTURE_VOLUME);
 129         volume->io.offset = 0LL;
 130         volume->io.bytes = HAMMER_BUFSIZE;
 131
 132         /*
 133          * Get the device vnode
 134          */
 135         if (devvp == NULL) {
 136                 error = nlookup_init(&nd, volume->vol_name, UIO_SYSSPACE, NLC_FOLLOW);
 137                 if (error == 0)
 138                         error = nlookup(&nd);
 139                 if (error == 0)
 140                         error = cache_vref(&nd.nl_nch, nd.nl_cred, &volume->devvp);
 141                 nlookup_done(&nd);
 142         } else {
 143                 error = 0;
 144                 volume->devvp = devvp;
 145         }
 146
 147         if (error == 0) {
 148                 if (vn_isdisk(volume->devvp, &error)) {
 149                         error = vfs_mountedon(volume->devvp);
 150                 }
 151         }
 152         if (error == 0 && vcount(volume->devvp) > 0)
 153                 error = EBUSY;
 154         if (error == 0) {
 155                 vn_lock(volume->devvp, LK_EXCLUSIVE | LK_RETRY);
 156                 error = vinvalbuf(volume->devvp, V_SAVE, 0, 0);
 157                 if (error == 0) {
 158                         error = VOP_OPEN(volume->devvp,
 159                                          (ronly ? FREAD : FREAD|FWRITE),
 160                                          FSCRED, NULL);
 161                 }
 162                 vn_unlock(volume->devvp);
 163         }
 164         if (error) {
 165                 hammer_free_volume(volume);
 166                 return(error);
 167         }
 168         volume->devvp->v_rdev->si_mountpoint = mp;
 169         setmp = 1;
 170
 171         /*
 172          * Extract the volume number from the volume header and do various
 173          * sanity checks.
 174          */
 175         error = bread(volume->devvp, 0LL, HAMMER_BUFSIZE, &bp);
 176         if (error)
 177                 goto late_failure;
 178         ondisk = (void *)bp->b_data;
 179         if (ondisk->vol_signature != HAMMER_FSBUF_VOLUME) {
 180                 kprintf("hammer_mount: volume %s has an invalid header\n",
 181                         volume->vol_name);
 182                 error = EFTYPE;
 183                 goto late_failure;
 184         }
 185         volume->vol_no = ondisk->vol_no;
 186         volume->buffer_base = ondisk->vol_buf_beg;
 187         volume->vol_flags = ondisk->vol_flags;
 188         volume->nblocks = ondisk->vol_nblocks;
 189         volume->maxbuf_off = HAMMER_ENCODE_RAW_BUFFER(volume->vol_no,
 190                                     ondisk->vol_buf_end - ondisk->vol_buf_beg);
 191         volume->maxraw_off = ondisk->vol_buf_end;
 192
 193         if (RB_EMPTY(&hmp->rb_vols_root)) {
 194                 hmp->fsid = ondisk->vol_fsid;
 195         } else if (bcmp(&hmp->fsid, &ondisk->vol_fsid, sizeof(uuid_t))) {
 196                 kprintf("hammer_mount: volume %s's fsid does not match "
 197                         "other volumes\n", volume->vol_name);
 198                 error = EFTYPE;
 199                 goto late_failure;
 200         }
 201
 202         /*
 203          * Insert the volume structure into the red-black tree.
 204          */
 205         if (RB_INSERT(hammer_vol_rb_tree, &hmp->rb_vols_root, volume)) {
 206                 kprintf("hammer_mount: volume %s has a duplicate vol_no %d\n",
 207                         volume->vol_name, volume->vol_no);
 208                 error = EEXIST;
 209         }
 210
 211         /*
 212          * Set the root volume .  HAMMER special cases rootvol the structure.
 213          * We do not hold a ref because this would prevent related I/O
 214          * from being flushed.
 215          */
 216         if (error == 0 && ondisk->vol_rootvol == ondisk->vol_no) {
 217                 hmp->rootvol = volume;
 218                 hmp->nvolumes = ondisk->vol_count;
 219                 if (bp) {
 220                         brelse(bp);
 221                         bp = NULL;
 222                 }
 223                 hmp->mp->mnt_stat.f_blocks += ondisk->vol0_stat_bigblocks *
 224                         (HAMMER_LARGEBLOCK_SIZE / HAMMER_BUFSIZE);
 225                 hmp->mp->mnt_vstat.f_blocks += ondisk->vol0_stat_bigblocks *
 226                         (HAMMER_LARGEBLOCK_SIZE / HAMMER_BUFSIZE);
 227         }
 228 late_failure:
 229         if (bp)
 230                 brelse(bp);
 231         if (error) {
 232                 /*vinvalbuf(volume->devvp, V_SAVE, 0, 0);*/
 233                 if (setmp)
 234                         volume->devvp->v_rdev->si_mountpoint = NULL;
 235                 VOP_CLOSE(volume->devvp, ronly ? FREAD : FREAD|FWRITE);
 236                 hammer_free_volume(volume);
 237         }
 238         return (error);
 239 }
 240
 241 /*
 242  * This is called for each volume when updating the mount point from
 243  * read-write to read-only or vise-versa.
 244  */
 245 int
 246 hammer_adjust_volume_mode(hammer_volume_t volume, void *data __unused)
 247 {
 248         if (volume->devvp) {
 249                 vn_lock(volume->devvp, LK_EXCLUSIVE | LK_RETRY);
 250                 if (volume->io.hmp->ronly) {
 251                         /* do not call vinvalbuf */
 252                         VOP_OPEN(volume->devvp, FREAD, FSCRED, NULL);
 253                         VOP_CLOSE(volume->devvp, FREAD|FWRITE);
 254                 } else {
 255                         /* do not call vinvalbuf */
 256                         VOP_OPEN(volume->devvp, FREAD|FWRITE, FSCRED, NULL);
 257                         VOP_CLOSE(volume->devvp, FREAD);
 258                 }
 259                 vn_unlock(volume->devvp);
 260         }
 261         return(0);
 262 }
 263
 264 /*
 265  * Unload and free a HAMMER volume.  Must return >= 0 to continue scan
 266  * so returns -1 on failure.
 267  */
 268 int
 269 hammer_unload_volume(hammer_volume_t volume, void *data __unused)
 270 {
 271         hammer_mount_t hmp = volume->io.hmp;
 272         int ronly = ((hmp->mp->mnt_flag & MNT_RDONLY) ? 1 : 0);
 273         struct buf *bp;
 274
 275         /*
 276          * Clean up the root volume pointer, which is held unlocked in hmp.
 277          */
 278         if (hmp->rootvol == volume)
 279                 hmp->rootvol = NULL;
 280
 281         /*
 282          * We must not flush a dirty buffer to disk on umount.  It should
 283          * have already been dealt with by the flusher, or we may be in
 284          * catastrophic failure.
 285          */
 286         hammer_io_clear_modify(&volume->io, 1);
 287         volume->io.waitdep = 1;
 288         bp = hammer_io_release(&volume->io, 1);
 289
 290         /*
 291          * Clean up the persistent ref ioerror might have on the volume
 292          */
 293         if (volume->io.ioerror) {
 294                 volume->io.ioerror = 0;
 295                 hammer_unref(&volume->io.lock);
 296         }
 297
 298         /*
 299          * There should be no references on the volume, no clusters, and
 300          * no super-clusters.
 301          */
 302         KKASSERT(volume->io.lock.refs == 0);
 303         if (bp)
 304                 brelse(bp);
 305
 306         volume->ondisk = NULL;
 307         if (volume->devvp) {
 308                 if (volume->devvp->v_rdev &&
 309                     volume->devvp->v_rdev->si_mountpoint == hmp->mp
 310                 ) {
 311                         volume->devvp->v_rdev->si_mountpoint = NULL;
 312                 }
 313                 if (ronly) {
 314                         /*
 315                          * Make sure we don't sync anything to disk if we
 316                          * are in read-only mode (1) or critically-errored
 317                          * (2).  Note that there may be dirty buffers in
 318                          * normal read-only mode from crash recovery.
 319                          */
 320                         vinvalbuf(volume->devvp, 0, 0, 0);
 321                         VOP_CLOSE(volume->devvp, FREAD);
 322                 } else {
 323                         /*
 324                          * Normal termination, save any dirty buffers
 325                          * (XXX there really shouldn't be any).
 326                          */
 327                         vinvalbuf(volume->devvp, V_SAVE, 0, 0);
 328                         VOP_CLOSE(volume->devvp, FREAD|FWRITE);
 329                 }
 330         }
 331
 332         /*
 333          * Destroy the structure
 334          */
 335         RB_REMOVE(hammer_vol_rb_tree, &hmp->rb_vols_root, volume);
 336         hammer_free_volume(volume);
 337         return(0);
 338 }
 339
 340 static
 341 void
 342 hammer_free_volume(hammer_volume_t volume)
 343 {
 344         hammer_mount_t hmp = volume->io.hmp;
 345
 346         if (volume->vol_name) {
 347                 kfree(volume->vol_name, hmp->m_misc);
 348                 volume->vol_name = NULL;
 349         }
 350         if (volume->devvp) {
 351                 vrele(volume->devvp);
 352                 volume->devvp = NULL;
 353         }
 354         --hammer_count_volumes;
 355         kfree(volume, hmp->m_misc);
 356 }
 357
 358 /*
 359  * Get a HAMMER volume.  The volume must already exist.
 360  */
 361 hammer_volume_t
 362 hammer_get_volume(struct hammer_mount *hmp, int32_t vol_no, int *errorp)
 363 {
 364         struct hammer_volume *volume;
 365
 366         /*
 367          * Locate the volume structure
 368          */
 369         volume = RB_LOOKUP(hammer_vol_rb_tree, &hmp->rb_vols_root, vol_no);
 370         if (volume == NULL) {
 371                 *errorp = ENOENT;
 372                 return(NULL);
 373         }
 374         hammer_ref(&volume->io.lock);
 375
 376         /*
 377          * Deal with on-disk info
 378          */
 379         if (volume->ondisk == NULL || volume->io.loading) {
 380                 *errorp = hammer_load_volume(volume);
 381                 if (*errorp) {
 382                         hammer_rel_volume(volume, 1);
 383                         volume = NULL;
 384                 }
 385         } else {
 386                 *errorp = 0;
 387         }
 388         return(volume);
 389 }
 390
 391 int
 392 hammer_ref_volume(hammer_volume_t volume)
 393 {
 394         int error;
 395
 396         hammer_ref(&volume->io.lock);
 397
 398         /*
 399          * Deal with on-disk info
 400          */
 401         if (volume->ondisk == NULL || volume->io.loading) {
 402                 error = hammer_load_volume(volume);
 403                 if (error)
 404                         hammer_rel_volume(volume, 1);
 405         } else {
 406                 error = 0;
 407         }
 408         return (error);
 409 }
 410
 411 hammer_volume_t
 412 hammer_get_root_volume(struct hammer_mount *hmp, int *errorp)
 413 {
 414         hammer_volume_t volume;
 415
 416         volume = hmp->rootvol;
 417         KKASSERT(volume != NULL);
 418         hammer_ref(&volume->io.lock);
 419
 420         /*
 421          * Deal with on-disk info
 422          */
 423         if (volume->ondisk == NULL || volume->io.loading) {
 424                 *errorp = hammer_load_volume(volume);
 425                 if (*errorp) {
 426                         hammer_rel_volume(volume, 1);
 427                         volume = NULL;
 428                 }
 429         } else {
 430                 *errorp = 0;
 431         }
 432         return (volume);
 433 }
 434
 435 /*
 436  * Load a volume's on-disk information.  The volume must be referenced and
 437  * not locked.  We temporarily acquire an exclusive lock to interlock
 438  * against releases or multiple get's.
 439  */
 440 static int
 441 hammer_load_volume(hammer_volume_t volume)
 442 {
 443         int error;
 444
 445         ++volume->io.loading;
 446         hammer_lock_ex(&volume->io.lock);
 447
 448         if (volume->ondisk == NULL) {
 449                 error = hammer_io_read(volume->devvp, &volume->io,
 450                                        volume->maxraw_off);
 451                 if (error == 0)
 452                         volume->ondisk = (void *)volume->io.bp->b_data;
 453         } else {
 454                 error = 0;
 455         }
 456         --volume->io.loading;
 457         hammer_unlock(&volume->io.lock);
 458         return(error);
 459 }
 460
 461 /*
 462  * Release a volume.  Call hammer_io_release on the last reference.  We have
 463  * to acquire an exclusive lock to interlock against volume->ondisk tests
 464  * in hammer_load_volume(), and hammer_io_release() also expects an exclusive
 465  * lock to be held.
 466  *
 467  * Volumes are not unloaded from memory during normal operation.
 468  */
 469 void
 470 hammer_rel_volume(hammer_volume_t volume, int flush)
 471 {
 472         struct buf *bp = NULL;
 473
 474         crit_enter();
 475         if (volume->io.lock.refs == 1) {
 476                 ++volume->io.loading;
 477                 hammer_lock_ex(&volume->io.lock);
 478                 if (volume->io.lock.refs == 1) {
 479                         volume->ondisk = NULL;
 480                         bp = hammer_io_release(&volume->io, flush);
 481                 }
 482                 --volume->io.loading;
 483                 hammer_unlock(&volume->io.lock);
 484         }
 485         hammer_unref(&volume->io.lock);
 486         if (bp)
 487                 brelse(bp);
 488         crit_exit();
 489 }
 490
 491 int
 492 hammer_mountcheck_volumes(struct hammer_mount *hmp)
 493 {
 494         hammer_volume_t vol;
 495         int i;
 496
 497         for (i = 0; i < hmp->nvolumes; ++i) {
 498                 vol = RB_LOOKUP(hammer_vol_rb_tree, &hmp->rb_vols_root, i);
 499                 if (vol == NULL)
 500                         return(EINVAL);
 501         }
 502         return(0);
 503 }
 504
 505 /************************************************************************
 506  *                              BUFFERS                                 *
 507  ************************************************************************
 508  *
 509  * Manage buffers.  Currently most blockmap-backed zones are direct-mapped
 510  * to zone-2 buffer offsets, without a translation stage.  However, the
 511  * hammer_buffer structure is indexed by its zoneX_offset, not its
 512  * zone2_offset.
 513  *
 514  * The proper zone must be maintained throughout the code-base all the way
 515  * through to the big-block allocator, or routines like hammer_del_buffers()
 516  * will not be able to locate all potentially conflicting buffers.
 517  */
 518 hammer_buffer_t
 519 hammer_get_buffer(hammer_mount_t hmp, hammer_off_t buf_offset,
 520                   int bytes, int isnew, int *errorp)
 521 {
 522         hammer_buffer_t buffer;
 523         hammer_volume_t volume;
 524         hammer_off_t    zone2_offset;
 525         hammer_io_type_t iotype;
 526         int vol_no;
 527         int zone;
 528
 529         buf_offset &= ~HAMMER_BUFMASK64;
 530 again:
 531         /*
 532          * Shortcut if the buffer is already cached
 533          */
 534         buffer = RB_LOOKUP(hammer_buf_rb_tree, &hmp->rb_bufs_root, buf_offset);
 535         if (buffer) {
 536                 if (buffer->io.lock.refs == 0)
 537                         ++hammer_count_refedbufs;
 538                 hammer_ref(&buffer->io.lock);
 539
 540                 /*
 541                  * Once refed the ondisk field will not be cleared by
 542                  * any other action.
 543                  */
 544                 if (buffer->ondisk && buffer->io.loading == 0) {
 545                         *errorp = 0;
 546                         hammer_io_advance(&buffer->io);
 547                         return(buffer);
 548                 }
 549
 550                 /*
 551                  * The buffer is no longer loose if it has a ref, and
 552                  * cannot become loose once it gains a ref.  Loose
 553                  * buffers will never be in a modified state.  This should
 554                  * only occur on the 0->1 transition of refs.
 555                  *
 556                  * lose_list can be modified via a biodone() interrupt.
 557                  */
 558                 if (buffer->io.mod_list == &hmp->lose_list) {
 559                         crit_enter();   /* biodone race against list */
 560                         TAILQ_REMOVE(buffer->io.mod_list, &buffer->io,
 561                                      mod_entry);
 562                         crit_exit();
 563                         buffer->io.mod_list = NULL;
 564                         KKASSERT(buffer->io.modified == 0);
 565                 }
 566                 goto found;
 567         }
 568
 569         /*
 570          * What is the buffer class?
 571          */
 572         zone = HAMMER_ZONE_DECODE(buf_offset);
 573
 574         switch(zone) {
 575         case HAMMER_ZONE_LARGE_DATA_INDEX:
 576         case HAMMER_ZONE_SMALL_DATA_INDEX:
 577                 iotype = HAMMER_STRUCTURE_DATA_BUFFER;
 578                 break;
 579         case HAMMER_ZONE_UNDO_INDEX:
 580                 iotype = HAMMER_STRUCTURE_UNDO_BUFFER;
 581                 break;
 582         case HAMMER_ZONE_META_INDEX:
 583         default:
 584                 /*
 585                  * NOTE: inode data and directory entries are placed in this
 586                  * zone.  inode atime/mtime is updated in-place and thus
 587                  * buffers containing inodes must be synchronized as
 588                  * meta-buffers, same as buffers containing B-Tree info.
 589                  */
 590                 iotype = HAMMER_STRUCTURE_META_BUFFER;
 591                 break;
 592         }
 593
 594         /*
 595          * Handle blockmap offset translations
 596          */
 597         if (zone >= HAMMER_ZONE_BTREE_INDEX) {
 598                 zone2_offset = hammer_blockmap_lookup(hmp, buf_offset, errorp);
 599         } else if (zone == HAMMER_ZONE_UNDO_INDEX) {
 600                 zone2_offset = hammer_undo_lookup(hmp, buf_offset, errorp);
 601         } else {
 602                 KKASSERT(zone == HAMMER_ZONE_RAW_BUFFER_INDEX);
 603                 zone2_offset = buf_offset;
 604                 *errorp = 0;
 605         }
 606         if (*errorp)
 607                 return(NULL);
 608
 609         /*
 610          * NOTE: zone2_offset and maxbuf_off are both full zone-2 offset
 611          * specifications.
 612          */
 613         KKASSERT((zone2_offset & HAMMER_OFF_ZONE_MASK) ==
 614                  HAMMER_ZONE_RAW_BUFFER);
 615         vol_no = HAMMER_VOL_DECODE(zone2_offset);
 616         volume = hammer_get_volume(hmp, vol_no, errorp);
 617         if (volume == NULL)
 618                 return(NULL);
 619
 620         KKASSERT(zone2_offset < volume->maxbuf_off);
 621
 622         /*
 623          * Allocate a new buffer structure.  We will check for races later.
 624          */
 625         ++hammer_count_buffers;
 626         buffer = kmalloc(sizeof(*buffer), hmp->m_misc,
 627                          M_WAITOK|M_ZERO|M_USE_RESERVE);
 628         buffer->zone2_offset = zone2_offset;
 629         buffer->zoneX_offset = buf_offset;
 630
 631         hammer_io_init(&buffer->io, volume, iotype);
 632         buffer->io.offset = volume->ondisk->vol_buf_beg +
 633                             (zone2_offset & HAMMER_OFF_SHORT_MASK);
 634         buffer->io.bytes = bytes;
 635         TAILQ_INIT(&buffer->clist);
 636         hammer_ref(&buffer->io.lock);
 637
 638         /*
 639          * Insert the buffer into the RB tree and handle late collisions.
 640          */
 641         if (RB_INSERT(hammer_buf_rb_tree, &hmp->rb_bufs_root, buffer)) {
 642                 hammer_rel_volume(volume, 0);
 643                 buffer->io.volume = NULL;       /* safety */
 644                 hammer_unref(&buffer->io.lock); /* safety */
 645                 --hammer_count_buffers;
 646                 kfree(buffer, hmp->m_misc);
 647                 goto again;
 648         }
 649         ++hammer_count_refedbufs;
 650 found:
 651
 652         /*
 653          * Deal with on-disk info and loading races.
 654          */
 655         if (buffer->ondisk == NULL || buffer->io.loading) {
 656                 *errorp = hammer_load_buffer(buffer, isnew);
 657                 if (*errorp) {
 658                         hammer_rel_buffer(buffer, 1);
 659                         buffer = NULL;
 660                 } else {
 661                         hammer_io_advance(&buffer->io);
 662                 }
 663         } else {
 664                 *errorp = 0;
 665                 hammer_io_advance(&buffer->io);
 666         }
 667         return(buffer);
 668 }
 669
 670 /*
 671  * This is used by the direct-read code to deal with large-data buffers
 672  * created by the reblocker and mirror-write code.  The direct-read code
 673  * bypasses the HAMMER buffer subsystem and so any aliased dirty or write-
 674  * running hammer buffers must be fully synced to disk before we can issue
 675  * the direct-read.
 676  *
 677  * This code path is not considered critical as only the rebocker and
 678  * mirror-write code will create large-data buffers via the HAMMER buffer
 679  * subsystem.  They do that because they operate at the B-Tree level and
 680  * do not access the vnode/inode structures.
 681  */
 682 void
 683 hammer_sync_buffers(hammer_mount_t hmp, hammer_off_t base_offset, int bytes)
 684 {
 685         hammer_buffer_t buffer;
 686         int error;
 687
 688         KKASSERT((base_offset & HAMMER_OFF_ZONE_MASK) ==
 689                  HAMMER_ZONE_LARGE_DATA);
 690
 691         while (bytes > 0) {
 692                 buffer = RB_LOOKUP(hammer_buf_rb_tree, &hmp->rb_bufs_root,
 693                                    base_offset);
 694                 if (buffer && (buffer->io.modified || buffer->io.running)) {
 695                         error = hammer_ref_buffer(buffer);
 696                         if (error == 0) {
 697                                 hammer_io_wait(&buffer->io);
 698                                 if (buffer->io.modified) {
 699                                         hammer_io_write_interlock(&buffer->io);
 700                                         hammer_io_flush(&buffer->io, 0);
 701                                         hammer_io_done_interlock(&buffer->io);
 702                                         hammer_io_wait(&buffer->io);
 703                                 }
 704                                 hammer_rel_buffer(buffer, 0);
 705                         }
 706                 }
 707                 base_offset += HAMMER_BUFSIZE;
 708                 bytes -= HAMMER_BUFSIZE;
 709         }
 710 }
 711
 712 /*
 713  * Destroy all buffers covering the specified zoneX offset range.  This
 714  * is called when the related blockmap layer2 entry is freed or when
 715  * a direct write bypasses our buffer/buffer-cache subsystem.
 716  *
 717  * The buffers may be referenced by the caller itself.  Setting reclaim
 718  * will cause the buffer to be destroyed when it's ref count reaches zero.
 719  *
 720  * Return 0 on success, EAGAIN if some buffers could not be destroyed due
 721  * to additional references held by other threads, or some other (typically
 722  * fatal) error.
 723  */
 724 int
 725 hammer_del_buffers(hammer_mount_t hmp, hammer_off_t base_offset,
 726                    hammer_off_t zone2_offset, int bytes,
 727                    int report_conflicts)
 728 {
 729         hammer_buffer_t buffer;
 730         hammer_volume_t volume;
 731         int vol_no;
 732         int error;
 733         int ret_error;
 734
 735         vol_no = HAMMER_VOL_DECODE(zone2_offset);
 736         volume = hammer_get_volume(hmp, vol_no, &ret_error);
 737         KKASSERT(ret_error == 0);
 738
 739         while (bytes > 0) {
 740                 buffer = RB_LOOKUP(hammer_buf_rb_tree, &hmp->rb_bufs_root,
 741                                    base_offset);
 742                 if (buffer) {
 743                         error = hammer_ref_buffer(buffer);
 744                         if (error == 0 && buffer->io.lock.refs != 1) {
 745                                 error = EAGAIN;
 746                                 hammer_rel_buffer(buffer, 0);
 747                         }
 748                         if (error == 0) {
 749                                 KKASSERT(buffer->zone2_offset == zone2_offset);
 750                                 hammer_io_clear_modify(&buffer->io, 1);
 751                                 buffer->io.reclaim = 1;
 752                                 buffer->io.waitdep = 1;
 753                                 KKASSERT(buffer->io.volume == volume);
 754                                 hammer_rel_buffer(buffer, 0);
 755                         }
 756                 } else {
 757                         error = hammer_io_inval(volume, zone2_offset);
 758                 }
 759                 if (error) {
 760                         ret_error = error;
 761                         if (report_conflicts ||
 762                             (hammer_debug_general & 0x8000)) {
 763                                 kprintf("hammer_del_buffers: unable to "
 764                                         "invalidate %016llx buffer=%p rep=%d\n",
 765                                         (long long)base_offset,
 766                                         buffer, report_conflicts);
 767                         }
 768                 }
 769                 base_offset += HAMMER_BUFSIZE;
 770                 zone2_offset += HAMMER_BUFSIZE;
 771                 bytes -= HAMMER_BUFSIZE;
 772         }
 773         hammer_rel_volume(volume, 0);
 774         return (ret_error);
 775 }
 776
 777 static int
 778 hammer_load_buffer(hammer_buffer_t buffer, int isnew)
 779 {
 780         hammer_volume_t volume;
 781         int error;
 782
 783         /*
 784          * Load the buffer's on-disk info
 785          */
 786         volume = buffer->io.volume;
 787         ++buffer->io.loading;
 788         hammer_lock_ex(&buffer->io.lock);
 789
 790         if (hammer_debug_io & 0x0001) {
 791                 kprintf("load_buffer %016llx %016llx isnew=%d od=%p\n",
 792                         (long long)buffer->zoneX_offset,
 793                         (long long)buffer->zone2_offset,
 794                         isnew, buffer->ondisk);
 795         }
 796
 797         if (buffer->ondisk == NULL) {
 798                 if (isnew) {
 799                         error = hammer_io_new(volume->devvp, &buffer->io);
 800                 } else {
 801                         error = hammer_io_read(volume->devvp, &buffer->io,
 802                                                volume->maxraw_off);
 803                 }
 804                 if (error == 0)
 805                         buffer->ondisk = (void *)buffer->io.bp->b_data;
 806         } else if (isnew) {
 807                 error = hammer_io_new(volume->devvp, &buffer->io);
 808         } else {
 809                 error = 0;
 810         }
 811         --buffer->io.loading;
 812         hammer_unlock(&buffer->io.lock);
 813         return (error);
 814 }
 815
 816 /*
 817  * NOTE: Called from RB_SCAN, must return >= 0 for scan to continue.
 818  * This routine is only called during unmount.
 819  */
 820 int
 821 hammer_unload_buffer(hammer_buffer_t buffer, void *data __unused)
 822 {
 823         /*
 824          * Clean up the persistent ref ioerror might have on the buffer
 825          * and acquire a ref (steal ioerror's if we can).
 826          */
 827         if (buffer->io.ioerror) {
 828                 buffer->io.ioerror = 0;
 829         } else {
 830                 if (buffer->io.lock.refs == 0)
 831                         ++hammer_count_refedbufs;
 832                 hammer_ref(&buffer->io.lock);
 833         }
 834
 835         /*
 836          * We must not flush a dirty buffer to disk on umount.  It should
 837          * have already been dealt with by the flusher, or we may be in
 838          * catastrophic failure.
 839          *
 840          * We must set waitdep to ensure that a running buffer is waited
 841          * on and released prior to us trying to unload the volume.
 842          */
 843         hammer_io_clear_modify(&buffer->io, 1);
 844         hammer_flush_buffer_nodes(buffer);
 845         KKASSERT(buffer->io.lock.refs == 1);
 846         buffer->io.waitdep = 1;
 847         hammer_rel_buffer(buffer, 2);
 848         return(0);
 849 }
 850
 851 /*
 852  * Reference a buffer that is either already referenced or via a specially
 853  * handled pointer (aka cursor->buffer).
 854  */
 855 int
 856 hammer_ref_buffer(hammer_buffer_t buffer)
 857 {
 858         int error;
 859
 860         if (buffer->io.lock.refs == 0)
 861                 ++hammer_count_refedbufs;
 862         hammer_ref(&buffer->io.lock);
 863
 864         /*
 865          * At this point a biodone() will not touch the buffer other then
 866          * incidental bits.  However, lose_list can be modified via
 867          * a biodone() interrupt.
 868          *
 869          * No longer loose
 870          */
 871         if (buffer->io.mod_list == &buffer->io.hmp->lose_list) {
 872                 crit_enter();
 873                 TAILQ_REMOVE(buffer->io.mod_list, &buffer->io, mod_entry);
 874                 buffer->io.mod_list = NULL;
 875                 crit_exit();
 876         }
 877
 878         if (buffer->ondisk == NULL || buffer->io.loading) {
 879                 error = hammer_load_buffer(buffer, 0);
 880                 if (error) {
 881                         hammer_rel_buffer(buffer, 1);
 882                         /*
 883                          * NOTE: buffer pointer can become stale after
 884                          * the above release.
 885                          */
 886                 }
 887         } else {
 888                 error = 0;
 889         }
 890         return(error);
 891 }
 892
 893 /*
 894  * Release a buffer.  We have to deal with several places where
 895  * another thread can ref the buffer.
 896  *
 897  * Only destroy the structure itself if the related buffer cache buffer
 898  * was disassociated from it.  This ties the management of the structure
 899  * to the buffer cache subsystem.  buffer->ondisk determines whether the
 900  * embedded io is referenced or not.
 901  */
 902 void
 903 hammer_rel_buffer(hammer_buffer_t buffer, int flush)
 904 {
 905         hammer_volume_t volume;
 906         hammer_mount_t hmp;
 907         struct buf *bp = NULL;
 908         int freeme = 0;
 909
 910         hmp = buffer->io.hmp;
 911
 912         crit_enter();
 913         if (buffer->io.lock.refs == 1) {
 914                 ++buffer->io.loading;   /* force interlock check */
 915                 hammer_lock_ex(&buffer->io.lock);
 916                 if (buffer->io.lock.refs == 1) {
 917                         bp = hammer_io_release(&buffer->io, flush);
 918
 919                         if (buffer->io.lock.refs == 1)
 920                                 --hammer_count_refedbufs;
 921
 922                         if (buffer->io.bp == NULL &&
 923                             buffer->io.lock.refs == 1) {
 924                                 /*
 925                                  * Final cleanup
 926                                  *
 927                                  * NOTE: It is impossible for any associated
 928                                  * B-Tree nodes to have refs if the buffer
 929                                  * has no additional refs.
 930                                  */
 931                                 RB_REMOVE(hammer_buf_rb_tree,
 932                                           &buffer->io.hmp->rb_bufs_root,
 933                                           buffer);
 934                                 volume = buffer->io.volume;
 935                                 buffer->io.volume = NULL; /* sanity */
 936                                 hammer_rel_volume(volume, 0);
 937                                 hammer_io_clear_modlist(&buffer->io);
 938                                 hammer_flush_buffer_nodes(buffer);
 939                                 KKASSERT(TAILQ_EMPTY(&buffer->clist));
 940                                 freeme = 1;
 941                         }
 942                 }
 943                 --buffer->io.loading;
 944                 hammer_unlock(&buffer->io.lock);
 945         }
 946         hammer_unref(&buffer->io.lock);
 947         crit_exit();
 948         if (bp)
 949                 brelse(bp);
 950         if (freeme) {
 951                 --hammer_count_buffers;
 952                 kfree(buffer, hmp->m_misc);
 953         }
 954 }
 955
 956 /*
 957  * Access the filesystem buffer containing the specified hammer offset.
 958  * buf_offset is a conglomeration of the volume number and vol_buf_beg
 959  * relative buffer offset.  It must also have bit 55 set to be valid.
 960  * (see hammer_off_t in hammer_disk.h).
 961  *
 962  * Any prior buffer in *bufferp will be released and replaced by the
 963  * requested buffer.
 964  *
 965  * NOTE: The buffer is indexed via its zoneX_offset but we allow the
 966  * passed cached *bufferp to match against either zoneX or zone2.
 967  */
 968 static __inline
 969 void *
 970 _hammer_bread(hammer_mount_t hmp, hammer_off_t buf_offset, int bytes,
 971              int *errorp, struct hammer_buffer **bufferp)
 972 {
 973         hammer_buffer_t buffer;
 974         int32_t xoff = (int32_t)buf_offset & HAMMER_BUFMASK;
 975
 976         buf_offset &= ~HAMMER_BUFMASK64;
 977         KKASSERT((buf_offset & HAMMER_OFF_ZONE_MASK) != 0);
 978
 979         buffer = *bufferp;
 980         if (buffer == NULL || (buffer->zone2_offset != buf_offset &&
 981                                buffer->zoneX_offset != buf_offset)) {
 982                 if (buffer)
 983                         hammer_rel_buffer(buffer, 0);
 984                 buffer = hammer_get_buffer(hmp, buf_offset, bytes, 0, errorp);
 985                 *bufferp = buffer;
 986         } else {
 987                 *errorp = 0;
 988         }
 989
 990         /*
 991          * Return a pointer to the buffer data.
 992          */
 993         if (buffer == NULL)
 994                 return(NULL);
 995         else
 996                 return((char *)buffer->ondisk + xoff);
 997 }
 998
 999 void *
1000 hammer_bread(hammer_mount_t hmp, hammer_off_t buf_offset,
1001              int *errorp, struct hammer_buffer **bufferp)
1002 {
1003         return(_hammer_bread(hmp, buf_offset, HAMMER_BUFSIZE, errorp, bufferp));
1004 }
1005
1006 void *
1007 hammer_bread_ext(hammer_mount_t hmp, hammer_off_t buf_offset, int bytes,
1008                  int *errorp, struct hammer_buffer **bufferp)
1009 {
1010         bytes = (bytes + HAMMER_BUFMASK) & ~HAMMER_BUFMASK;
1011         return(_hammer_bread(hmp, buf_offset, bytes, errorp, bufferp));
1012 }
1013
1014 /*
1015  * Access the filesystem buffer containing the specified hammer offset.
1016  * No disk read operation occurs.  The result buffer may contain garbage.
1017  *
1018  * Any prior buffer in *bufferp will be released and replaced by the
1019  * requested buffer.
1020  *
1021  * This function marks the buffer dirty but does not increment its
1022  * modify_refs count.
1023  */
1024 static __inline
1025 void *
1026 _hammer_bnew(hammer_mount_t hmp, hammer_off_t buf_offset, int bytes,
1027              int *errorp, struct hammer_buffer **bufferp)
1028 {
1029         hammer_buffer_t buffer;
1030         int32_t xoff = (int32_t)buf_offset & HAMMER_BUFMASK;
1031
1032         buf_offset &= ~HAMMER_BUFMASK64;
1033
1034         buffer = *bufferp;
1035         if (buffer == NULL || (buffer->zone2_offset != buf_offset &&
1036                                buffer->zoneX_offset != buf_offset)) {
1037                 if (buffer)
1038                         hammer_rel_buffer(buffer, 0);
1039                 buffer = hammer_get_buffer(hmp, buf_offset, bytes, 1, errorp);
1040                 *bufferp = buffer;
1041         } else {
1042                 *errorp = 0;
1043         }
1044
1045         /*
1046          * Return a pointer to the buffer data.
1047          */
1048         if (buffer == NULL)
1049                 return(NULL);
1050         else
1051                 return((char *)buffer->ondisk + xoff);
1052 }
1053
1054 void *
1055 hammer_bnew(hammer_mount_t hmp, hammer_off_t buf_offset,
1056              int *errorp, struct hammer_buffer **bufferp)
1057 {
1058         return(_hammer_bnew(hmp, buf_offset, HAMMER_BUFSIZE, errorp, bufferp));
1059 }
1060
1061 void *
1062 hammer_bnew_ext(hammer_mount_t hmp, hammer_off_t buf_offset, int bytes,
1063                 int *errorp, struct hammer_buffer **bufferp)
1064 {
1065         bytes = (bytes + HAMMER_BUFMASK) & ~HAMMER_BUFMASK;
1066         return(_hammer_bnew(hmp, buf_offset, bytes, errorp, bufferp));
1067 }
1068
1069 /************************************************************************
1070  *                              NODES                                   *
1071  ************************************************************************
1072  *
1073  * Manage B-Tree nodes.  B-Tree nodes represent the primary indexing
1074  * method used by the HAMMER filesystem.
1075  *
1076  * Unlike other HAMMER structures, a hammer_node can be PASSIVELY
1077  * associated with its buffer, and will only referenced the buffer while
1078  * the node itself is referenced.
1079  *
1080  * A hammer_node can also be passively associated with other HAMMER
1081  * structures, such as inodes, while retaining 0 references.  These
1082  * associations can be cleared backwards using a pointer-to-pointer in
1083  * the hammer_node.
1084  *
1085  * This allows the HAMMER implementation to cache hammer_nodes long-term
1086  * and short-cut a great deal of the infrastructure's complexity.  In
1087  * most cases a cached node can be reacquired without having to dip into
1088  * either the buffer or cluster management code.
1089  *
1090  * The caller must pass a referenced cluster on call and will retain
1091  * ownership of the reference on return.  The node will acquire its own
1092  * additional references, if necessary.
1093  */
1094 hammer_node_t
1095 hammer_get_node(hammer_transaction_t trans, hammer_off_t node_offset,
1096                 int isnew, int *errorp)
1097 {
1098         hammer_mount_t hmp = trans->hmp;
1099         hammer_node_t node;
1100
1101         KKASSERT((node_offset & HAMMER_OFF_ZONE_MASK) == HAMMER_ZONE_BTREE);
1102
1103         /*
1104          * Locate the structure, allocating one if necessary.
1105          */
1106 again:
1107         node = RB_LOOKUP(hammer_nod_rb_tree, &hmp->rb_nods_root, node_offset);
1108         if (node == NULL) {
1109                 ++hammer_count_nodes;
1110                 node = kmalloc(sizeof(*node), hmp->m_misc, M_WAITOK|M_ZERO|M_USE_RESERVE);
1111                 node->node_offset = node_offset;
1112                 node->hmp = hmp;
1113                 TAILQ_INIT(&node->cursor_list);
1114                 TAILQ_INIT(&node->cache_list);
1115                 if (RB_INSERT(hammer_nod_rb_tree, &hmp->rb_nods_root, node)) {
1116                         --hammer_count_nodes;
1117                         kfree(node, hmp->m_misc);
1118                         goto again;
1119                 }
1120         }
1121         hammer_ref(&node->lock);
1122         if (node->ondisk) {
1123                 *errorp = 0;
1124                 hammer_io_advance(&node->buffer->io);
1125         } else {
1126                 *errorp = hammer_load_node(trans, node, isnew);
1127                 trans->flags |= HAMMER_TRANSF_DIDIO;
1128         }
1129         if (*errorp) {
1130                 hammer_rel_node(node);
1131                 node = NULL;
1132         }
1133         return(node);
1134 }
1135
1136 /*
1137  * Reference an already-referenced node.
1138  */
1139 void
1140 hammer_ref_node(hammer_node_t node)
1141 {
1142         KKASSERT(node->lock.refs > 0 && node->ondisk != NULL);
1143         hammer_ref(&node->lock);
1144 }
1145
1146 /*
1147  * Load a node's on-disk data reference.
1148  */
1149 static int
1150 hammer_load_node(hammer_transaction_t trans, hammer_node_t node, int isnew)
1151 {
1152         hammer_buffer_t buffer;
1153         hammer_off_t buf_offset;
1154         int error;
1155
1156         error = 0;
1157         ++node->loading;
1158         hammer_lock_ex(&node->lock);
1159         if (node->ondisk == NULL) {
1160                 /*
1161                  * This is a little confusing but the jist is that
1162                  * node->buffer determines whether the node is on
1163                  * the buffer's clist and node->ondisk determines
1164                  * whether the buffer is referenced.
1165                  *
1166                  * We could be racing a buffer release, in which case
1167                  * node->buffer may become NULL while we are blocked
1168                  * referencing the buffer.
1169                  */
1170                 if ((buffer = node->buffer) != NULL) {
1171                         error = hammer_ref_buffer(buffer);
1172                         if (error == 0 && node->buffer == NULL) {
1173                                 TAILQ_INSERT_TAIL(&buffer->clist,
1174                                                   node, entry);
1175                                 node->buffer = buffer;
1176                         }
1177                 } else {
1178                         buf_offset = node->node_offset & ~HAMMER_BUFMASK64;
1179                         buffer = hammer_get_buffer(node->hmp, buf_offset,
1180                                                    HAMMER_BUFSIZE, 0, &error);
1181                         if (buffer) {
1182                                 KKASSERT(error == 0);
1183                                 TAILQ_INSERT_TAIL(&buffer->clist,
1184                                                   node, entry);
1185                                 node->buffer = buffer;
1186                         }
1187                 }
1188                 if (error)
1189                         goto failed;
1190                 node->ondisk = (void *)((char *)buffer->ondisk +
1191                                         (node->node_offset & HAMMER_BUFMASK));
1192
1193                 /*
1194                  * Check CRC.  NOTE: Neither flag is set and the CRC is not
1195                  * generated on new B-Tree nodes.
1196                  */
1197                 if (isnew == 0 &&
1198                     (node->flags & HAMMER_NODE_CRCANY) == 0) {
1199                         if (hammer_crc_test_btree(node->ondisk) == 0) {
1200                                 if (hammer_debug_critical)
1201                                         Debugger("CRC FAILED: B-TREE NODE");
1202                                 node->flags |= HAMMER_NODE_CRCBAD;
1203                         } else {
1204                                 node->flags |= HAMMER_NODE_CRCGOOD;
1205                         }
1206                 }
1207         }
1208         if (node->flags & HAMMER_NODE_CRCBAD) {
1209                 if (trans->flags & HAMMER_TRANSF_CRCDOM)
1210                         error = EDOM;
1211                 else
1212                         error = EIO;
1213         }
1214 failed:
1215         --node->loading;
1216         hammer_unlock(&node->lock);
1217         return (error);
1218 }
1219
1220 /*
1221  * Safely reference a node, interlock against flushes via the IO subsystem.
1222  */
1223 hammer_node_t
1224 hammer_ref_node_safe(hammer_transaction_t trans, hammer_node_cache_t cache,
1225                      int *errorp)
1226 {
1227         hammer_node_t node;
1228
1229         node = cache->node;
1230         if (node != NULL) {
1231                 hammer_ref(&node->lock);
1232                 if (node->ondisk) {
1233                         if (node->flags & HAMMER_NODE_CRCBAD) {
1234                                 if (trans->flags & HAMMER_TRANSF_CRCDOM)
1235                                         *errorp = EDOM;
1236                                 else
1237                                         *errorp = EIO;
1238                         } else {
1239                                 *errorp = 0;
1240                         }
1241                 } else {
1242                         *errorp = hammer_load_node(trans, node, 0);
1243                 }
1244                 if (*errorp) {
1245                         hammer_rel_node(node);
1246                         node = NULL;
1247                 }
1248         } else {
1249                 *errorp = ENOENT;
1250         }
1251         return(node);
1252 }
1253
1254 /*
1255  * Release a hammer_node.  On the last release the node dereferences
1256  * its underlying buffer and may or may not be destroyed.
1257  */
1258 void
1259 hammer_rel_node(hammer_node_t node)
1260 {
1261         hammer_buffer_t buffer;
1262
1263         /*
1264          * If this isn't the last ref just decrement the ref count and
1265          * return.
1266          */
1267         if (node->lock.refs > 1) {
1268                 hammer_unref(&node->lock);
1269                 return;
1270         }
1271
1272         /*
1273          * If there is no ondisk info or no buffer the node failed to load,
1274          * remove the last reference and destroy the node.
1275          */
1276         if (node->ondisk == NULL) {
1277                 hammer_unref(&node->lock);
1278                 hammer_flush_node(node);
1279                 /* node is stale now */
1280                 return;
1281         }
1282
1283         /*
1284          * Do not disassociate the node from the buffer if it represents
1285          * a modified B-Tree node that still needs its crc to be generated.
1286          */
1287         if (node->flags & HAMMER_NODE_NEEDSCRC)
1288                 return;
1289
1290         /*
1291          * Do final cleanups and then either destroy the node and leave it
1292          * passively cached.  The buffer reference is removed regardless.
1293          */
1294         buffer = node->buffer;
1295         node->ondisk = NULL;
1296
1297         if ((node->flags & HAMMER_NODE_FLUSH) == 0) {
1298                 hammer_unref(&node->lock);
1299                 hammer_rel_buffer(buffer, 0);
1300                 return;
1301         }
1302
1303         /*
1304          * Destroy the node.
1305          */
1306         hammer_unref(&node->lock);
1307         hammer_flush_node(node);
1308         /* node is stale */
1309         hammer_rel_buffer(buffer, 0);
1310 }
1311
1312 /*
1313  * Free space on-media associated with a B-Tree node.
1314  */
1315 void
1316 hammer_delete_node(hammer_transaction_t trans, hammer_node_t node)
1317 {
1318         KKASSERT((node->flags & HAMMER_NODE_DELETED) == 0);
1319         node->flags |= HAMMER_NODE_DELETED;
1320         hammer_blockmap_free(trans, node->node_offset, sizeof(*node->ondisk));
1321 }
1322
1323 /*
1324  * Passively cache a referenced hammer_node.  The caller may release
1325  * the node on return.
1326  */
1327 void
1328 hammer_cache_node(hammer_node_cache_t cache, hammer_node_t node)
1329 {
1330         /*
1331          * If the node doesn't exist, or is being deleted, don't cache it!
1332          *
1333          * The node can only ever be NULL in the I/O failure path.
1334          */
1335         if (node == NULL || (node->flags & HAMMER_NODE_DELETED))
1336                 return;
1337         if (cache->node == node)
1338                 return;
1339         while (cache->node)
1340                 hammer_uncache_node(cache);
1341         if (node->flags & HAMMER_NODE_DELETED)
1342                 return;
1343         cache->node = node;
1344         TAILQ_INSERT_TAIL(&node->cache_list, cache, entry);
1345 }
1346
1347 void
1348 hammer_uncache_node(hammer_node_cache_t cache)
1349 {
1350         hammer_node_t node;
1351
1352         if ((node = cache->node) != NULL) {
1353                 TAILQ_REMOVE(&node->cache_list, cache, entry);
1354                 cache->node = NULL;
1355                 if (TAILQ_EMPTY(&node->cache_list))
1356                         hammer_flush_node(node);
1357         }
1358 }
1359
1360 /*
1361  * Remove a node's cache references and destroy the node if it has no
1362  * other references or backing store.
1363  */
1364 void
1365 hammer_flush_node(hammer_node_t node)
1366 {
1367         hammer_node_cache_t cache;
1368         hammer_buffer_t buffer;
1369         hammer_mount_t hmp = node->hmp;
1370
1371         while ((cache = TAILQ_FIRST(&node->cache_list)) != NULL) {
1372                 TAILQ_REMOVE(&node->cache_list, cache, entry);
1373                 cache->node = NULL;
1374         }
1375         if (node->lock.refs == 0 && node->ondisk == NULL) {
1376                 KKASSERT((node->flags & HAMMER_NODE_NEEDSCRC) == 0);
1377                 RB_REMOVE(hammer_nod_rb_tree, &node->hmp->rb_nods_root, node);
1378                 if ((buffer = node->buffer) != NULL) {
1379                         node->buffer = NULL;
1380                         TAILQ_REMOVE(&buffer->clist, node, entry);
1381                         /* buffer is unreferenced because ondisk is NULL */
1382                 }
1383                 --hammer_count_nodes;
1384                 kfree(node, hmp->m_misc);
1385         }
1386 }
1387
1388 /*
1389  * Flush passively cached B-Tree nodes associated with this buffer.
1390  * This is only called when the buffer is about to be destroyed, so
1391  * none of the nodes should have any references.  The buffer is locked.
1392  *
1393  * We may be interlocked with the buffer.
1394  */
1395 void
1396 hammer_flush_buffer_nodes(hammer_buffer_t buffer)
1397 {
1398         hammer_node_t node;
1399
1400         while ((node = TAILQ_FIRST(&buffer->clist)) != NULL) {
1401                 KKASSERT(node->ondisk == NULL);
1402                 KKASSERT((node->flags & HAMMER_NODE_NEEDSCRC) == 0);
1403
1404                 if (node->lock.refs == 0) {
1405                         hammer_ref(&node->lock);
1406                         node->flags |= HAMMER_NODE_FLUSH;
1407                         hammer_rel_node(node);
1408                 } else {
1409                         KKASSERT(node->loading != 0);
1410                         KKASSERT(node->buffer != NULL);
1411                         buffer = node->buffer;
1412                         node->buffer = NULL;
1413                         TAILQ_REMOVE(&buffer->clist, node, entry);
1414                         /* buffer is unreferenced because ondisk is NULL */
1415                 }
1416         }
1417 }
1418
1419
1420 /************************************************************************
1421  *                              ALLOCATORS                              *
1422  ************************************************************************/
1423
1424 /*
1425  * Allocate a B-Tree node.
1426  */
1427 hammer_node_t
1428 hammer_alloc_btree(hammer_transaction_t trans, hammer_off_t hint, int *errorp)
1429 {
1430         hammer_buffer_t buffer = NULL;
1431         hammer_node_t node = NULL;
1432         hammer_off_t node_offset;
1433
1434         node_offset = hammer_blockmap_alloc(trans, HAMMER_ZONE_BTREE_INDEX,
1435                                             sizeof(struct hammer_node_ondisk),
1436                                             hint, errorp);
1437         if (*errorp == 0) {
1438                 node = hammer_get_node(trans, node_offset, 1, errorp);
1439                 hammer_modify_node_noundo(trans, node);
1440                 bzero(node->ondisk, sizeof(*node->ondisk));
1441                 hammer_modify_node_done(node);
1442         }
1443         if (buffer)
1444                 hammer_rel_buffer(buffer, 0);
1445         return(node);
1446 }
1447
1448 /*
1449  * Allocate data.  If the address of a data buffer is supplied then
1450  * any prior non-NULL *data_bufferp will be released and *data_bufferp
1451  * will be set to the related buffer.  The caller must release it when
1452  * finally done.  The initial *data_bufferp should be set to NULL by
1453  * the caller.
1454  *
1455  * The caller is responsible for making hammer_modify*() calls on the
1456  * *data_bufferp.
1457  */
1458 void *
1459 hammer_alloc_data(hammer_transaction_t trans, int32_t data_len,
1460                   u_int16_t rec_type, hammer_off_t *data_offsetp,
1461                   struct hammer_buffer **data_bufferp,
1462                   hammer_off_t hint, int *errorp)
1463 {
1464         void *data;
1465         int zone;
1466
1467         /*
1468          * Allocate data
1469          */
1470         if (data_len) {
1471                 switch(rec_type) {
1472                 case HAMMER_RECTYPE_INODE:
1473                 case HAMMER_RECTYPE_DIRENTRY:
1474                 case HAMMER_RECTYPE_EXT:
1475                 case HAMMER_RECTYPE_FIX:
1476                 case HAMMER_RECTYPE_PFS:
1477                 case HAMMER_RECTYPE_SNAPSHOT:
1478                 case HAMMER_RECTYPE_CONFIG:
1479                         zone = HAMMER_ZONE_META_INDEX;
1480                         break;
1481                 case HAMMER_RECTYPE_DATA:
1482                 case HAMMER_RECTYPE_DB:
1483                         if (data_len <= HAMMER_BUFSIZE / 2) {
1484                                 zone = HAMMER_ZONE_SMALL_DATA_INDEX;
1485                         } else {
1486                                 data_len = (data_len + HAMMER_BUFMASK) &
1487                                            ~HAMMER_BUFMASK;
1488                                 zone = HAMMER_ZONE_LARGE_DATA_INDEX;
1489                         }
1490                         break;
1491                 default:
1492                         panic("hammer_alloc_data: rec_type %04x unknown",
1493                               rec_type);
1494                         zone = 0;       /* NOT REACHED */
1495                         break;
1496                 }
1497                 *data_offsetp = hammer_blockmap_alloc(trans, zone, data_len,
1498                                                       hint, errorp);
1499         } else {
1500                 *data_offsetp = 0;
1501         }
1502         if (*errorp == 0 && data_bufferp) {
1503                 if (data_len) {
1504                         data = hammer_bread_ext(trans->hmp, *data_offsetp,
1505                                                 data_len, errorp, data_bufferp);
1506                 } else {
1507                         data = NULL;
1508                 }
1509         } else {
1510                 data = NULL;
1511         }
1512         return(data);
1513 }
1514
1515 /*
1516  * Sync dirty buffers to the media and clean-up any loose ends.
1517  *
1518  * These functions do not start the flusher going, they simply
1519  * queue everything up to the flusher.
1520  */
1521 static int hammer_sync_scan1(struct mount *mp, struct vnode *vp, void *data);
1522 static int hammer_sync_scan2(struct mount *mp, struct vnode *vp, void *data);
1523
1524 int
1525 hammer_queue_inodes_flusher(hammer_mount_t hmp, int waitfor)
1526 {
1527         struct hammer_sync_info info;
1528
1529         info.error = 0;
1530         info.waitfor = waitfor;
1531         if (waitfor == MNT_WAIT) {
1532                 vmntvnodescan(hmp->mp, VMSC_GETVP|VMSC_ONEPASS,
1533                               hammer_sync_scan1, hammer_sync_scan2, &info);
1534         } else {
1535                 vmntvnodescan(hmp->mp, VMSC_GETVP|VMSC_ONEPASS|VMSC_NOWAIT,
1536                               hammer_sync_scan1, hammer_sync_scan2, &info);
1537         }
1538         return(info.error);
1539 }
1540
1541 /*
1542  * Filesystem sync.  If doing a synchronous sync make a second pass on
1543  * the vnodes in case any were already flushing during the first pass,
1544  * and activate the flusher twice (the second time brings the UNDO FIFO's
1545  * start position up to the end position after the first call).
1546  */
1547 int
1548 hammer_sync_hmp(hammer_mount_t hmp, int waitfor)
1549 {
1550         struct hammer_sync_info info;
1551
1552         info.error = 0;
1553         info.waitfor = MNT_NOWAIT;
1554         vmntvnodescan(hmp->mp, VMSC_GETVP|VMSC_NOWAIT,
1555                       hammer_sync_scan1, hammer_sync_scan2, &info);
1556         if (info.error == 0 && waitfor == MNT_WAIT) {
1557                 info.waitfor = waitfor;
1558                 vmntvnodescan(hmp->mp, VMSC_GETVP,
1559                               hammer_sync_scan1, hammer_sync_scan2, &info);
1560         }
1561         if (waitfor == MNT_WAIT) {
1562                 hammer_flusher_sync(hmp);
1563                 hammer_flusher_sync(hmp);
1564         } else {
1565                 hammer_flusher_async(hmp, NULL);
1566                 hammer_flusher_async(hmp, NULL);
1567         }
1568         return(info.error);
1569 }
1570
1571 static int
1572 hammer_sync_scan1(struct mount *mp, struct vnode *vp, void *data)
1573 {
1574         struct hammer_inode *ip;
1575
1576         ip = VTOI(vp);
1577         if (vp->v_type == VNON || ip == NULL ||
1578             ((ip->flags & HAMMER_INODE_MODMASK) == 0 &&
1579              RB_EMPTY(&vp->v_rbdirty_tree))) {
1580                 return(-1);
1581         }
1582         return(0);
1583 }
1584
1585 static int
1586 hammer_sync_scan2(struct mount *mp, struct vnode *vp, void *data)
1587 {
1588         struct hammer_sync_info *info = data;
1589         struct hammer_inode *ip;
1590         int error;
1591
1592         ip = VTOI(vp);
1593         if (vp->v_type == VNON || vp->v_type == VBAD ||
1594             ((ip->flags & HAMMER_INODE_MODMASK) == 0 &&
1595              RB_EMPTY(&vp->v_rbdirty_tree))) {
1596                 return(0);
1597         }
1598         error = VOP_FSYNC(vp, MNT_NOWAIT, 0);
1599         if (error)
1600                 info->error = error;
1601         return(0);
1602 }
1603