sys/vfs/hammer2/hammer2_strategy.c

   1 /*
   2  * Copyright (c) 2011-2015 The DragonFly Project.  All rights reserved.
   3  *
   4  * This code is derived from software contributed to The DragonFly Project
   5  * by Matthew Dillon <dillon@dragonflybsd.org>
   6  * by Venkatesh Srinivas <vsrinivas@dragonflybsd.org>
   7  * by Daniel Flores (GSOC 2013 - mentored by Matthew Dillon, compression)
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  *
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in
  17  *    the documentation and/or other materials provided with the
  18  *    distribution.
  19  * 3. Neither the name of The DragonFly Project nor the names of its
  20  *    contributors may be used to endorse or promote products derived
  21  *    from this software without specific, prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  24  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  25  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  26  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  27  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  28  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  29  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  30  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  31  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  32  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  33  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  34  * SUCH DAMAGE.
  35  */
  36 /*
  37  * This module handles low level logical file I/O (strategy) which backs
  38  * the logical buffer cache.
  39  *
  40  * [De]compression, zero-block, check codes, and buffer cache operations
  41  * for file data is handled here.
  42  *
  43  * Live dedup makes its home here as well.
  44  */
  45
  46 #include <sys/param.h>
  47 #include <sys/systm.h>
  48 #include <sys/kernel.h>
  49 #include <sys/fcntl.h>
  50 #include <sys/buf.h>
  51 #include <sys/proc.h>
  52 #include <sys/namei.h>
  53 #include <sys/mount.h>
  54 #include <sys/vnode.h>
  55 #include <sys/mountctl.h>
  56 #include <sys/dirent.h>
  57 #include <sys/uio.h>
  58 #include <sys/objcache.h>
  59 #include <sys/event.h>
  60 #include <sys/file.h>
  61 #include <vfs/fifofs/fifo.h>
  62
  63 #include "hammer2.h"
  64 #include "hammer2_lz4.h"
  65
  66 #include "zlib/hammer2_zlib.h"
  67
  68 struct objcache *cache_buffer_read;
  69 struct objcache *cache_buffer_write;
  70
  71 /*
  72  * Strategy code (async logical file buffer I/O from system)
  73  *
  74  * WARNING: The strategy code cannot safely use hammer2 transactions
  75  *          as this can deadlock against vfs_sync's vfsync() call
  76  *          if multiple flushes are queued.  All H2 structures must
  77  *          already be present and ready for the DIO.
  78  *
  79  *          Reads can be initiated asynchronously, writes have to be
  80  *          spooled to a separate thread for action to avoid deadlocks.
  81  */
  82 static void hammer2_strategy_xop_read(hammer2_xop_t *arg, int clindex);
  83 static void hammer2_strategy_xop_write(hammer2_xop_t *arg, int clindex);
  84 static int hammer2_strategy_read(struct vop_strategy_args *ap);
  85 static int hammer2_strategy_write(struct vop_strategy_args *ap);
  86 static void hammer2_strategy_read_completion(hammer2_chain_t *chain,
  87                                 char *data, struct bio *bio);
  88
  89 static void hammer2_dedup_record(hammer2_chain_t *chain, char *data);
  90 static hammer2_off_t hammer2_dedup_lookup(hammer2_dev_t *hmp,
  91                         char **datap, int pblksize);
  92
  93 int
  94 hammer2_vop_strategy(struct vop_strategy_args *ap)
  95 {
  96         struct bio *biop;
  97         struct buf *bp;
  98         int error;
  99
 100         biop = ap->a_bio;
 101         bp = biop->bio_buf;
 102
 103         switch(bp->b_cmd) {
 104         case BUF_CMD_READ:
 105                 error = hammer2_strategy_read(ap);
 106                 ++hammer2_iod_file_read;
 107                 break;
 108         case BUF_CMD_WRITE:
 109                 error = hammer2_strategy_write(ap);
 110                 ++hammer2_iod_file_write;
 111                 break;
 112         default:
 113                 bp->b_error = error = EINVAL;
 114                 bp->b_flags |= B_ERROR;
 115                 biodone(biop);
 116                 break;
 117         }
 118         return (error);
 119 }
 120
 121 /*
 122  * Return the largest contiguous physical disk range for the logical
 123  * request, in bytes.
 124  *
 125  * (struct vnode *vp, off_t loffset, off_t *doffsetp, int *runp, int *runb)
 126  *
 127  * Basically disabled, the logical buffer write thread has to deal with
 128  * buffers one-at-a-time.
 129  */
 130 int
 131 hammer2_vop_bmap(struct vop_bmap_args *ap)
 132 {
 133         *ap->a_doffsetp = NOOFFSET;
 134         if (ap->a_runp)
 135                 *ap->a_runp = 0;
 136         if (ap->a_runb)
 137                 *ap->a_runb = 0;
 138         return (EOPNOTSUPP);
 139 }
 140
 141 /****************************************************************************
 142  *                              READ SUPPORT                                *
 143  ****************************************************************************/
 144 /*
 145  * Callback used in read path in case that a block is compressed with LZ4.
 146  */
 147 static
 148 void
 149 hammer2_decompress_LZ4_callback(const char *data, u_int bytes, struct bio *bio)
 150 {
 151         struct buf *bp;
 152         char *compressed_buffer;
 153         int compressed_size;
 154         int result;
 155
 156         bp = bio->bio_buf;
 157
 158 #if 0
 159         if bio->bio_caller_info2.index &&
 160               bio->bio_caller_info1.uvalue32 !=
 161               crc32(bp->b_data, bp->b_bufsize) --- return error
 162 #endif
 163
 164         KKASSERT(bp->b_bufsize <= HAMMER2_PBUFSIZE);
 165         compressed_size = *(const int *)data;
 166         KKASSERT(compressed_size <= bytes - sizeof(int));
 167
 168         compressed_buffer = objcache_get(cache_buffer_read, M_INTWAIT);
 169         result = LZ4_decompress_safe(__DECONST(char *, &data[sizeof(int)]),
 170                                      compressed_buffer,
 171                                      compressed_size,
 172                                      bp->b_bufsize);
 173         if (result < 0) {
 174                 kprintf("READ PATH: Error during decompression."
 175                         "bio %016jx/%d\n",
 176                         (intmax_t)bio->bio_offset, bytes);
 177                 /* make sure it isn't random garbage */
 178                 bzero(compressed_buffer, bp->b_bufsize);
 179         }
 180         KKASSERT(result <= bp->b_bufsize);
 181         bcopy(compressed_buffer, bp->b_data, bp->b_bufsize);
 182         if (result < bp->b_bufsize)
 183                 bzero(bp->b_data + result, bp->b_bufsize - result);
 184         objcache_put(cache_buffer_read, compressed_buffer);
 185         bp->b_resid = 0;
 186         bp->b_flags |= B_AGE;
 187 }
 188
 189 /*
 190  * Callback used in read path in case that a block is compressed with ZLIB.
 191  * It is almost identical to LZ4 callback, so in theory they can be unified,
 192  * but we didn't want to make changes in bio structure for that.
 193  */
 194 static
 195 void
 196 hammer2_decompress_ZLIB_callback(const char *data, u_int bytes, struct bio *bio)
 197 {
 198         struct buf *bp;
 199         char *compressed_buffer;
 200         z_stream strm_decompress;
 201         int result;
 202         int ret;
 203
 204         bp = bio->bio_buf;
 205
 206         KKASSERT(bp->b_bufsize <= HAMMER2_PBUFSIZE);
 207         strm_decompress.avail_in = 0;
 208         strm_decompress.next_in = Z_NULL;
 209
 210         ret = inflateInit(&strm_decompress);
 211
 212         if (ret != Z_OK)
 213                 kprintf("HAMMER2 ZLIB: Fatal error in inflateInit.\n");
 214
 215         compressed_buffer = objcache_get(cache_buffer_read, M_INTWAIT);
 216         strm_decompress.next_in = __DECONST(char *, data);
 217
 218         /* XXX supply proper size, subset of device bp */
 219         strm_decompress.avail_in = bytes;
 220         strm_decompress.next_out = compressed_buffer;
 221         strm_decompress.avail_out = bp->b_bufsize;
 222
 223         ret = inflate(&strm_decompress, Z_FINISH);
 224         if (ret != Z_STREAM_END) {
 225                 kprintf("HAMMER2 ZLIB: Fatar error during decompression.\n");
 226                 bzero(compressed_buffer, bp->b_bufsize);
 227         }
 228         bcopy(compressed_buffer, bp->b_data, bp->b_bufsize);
 229         result = bp->b_bufsize - strm_decompress.avail_out;
 230         if (result < bp->b_bufsize)
 231                 bzero(bp->b_data + result, strm_decompress.avail_out);
 232         objcache_put(cache_buffer_read, compressed_buffer);
 233         ret = inflateEnd(&strm_decompress);
 234
 235         bp->b_resid = 0;
 236         bp->b_flags |= B_AGE;
 237 }
 238
 239 /*
 240  * Logical buffer I/O, async read.
 241  */
 242 static
 243 int
 244 hammer2_strategy_read(struct vop_strategy_args *ap)
 245 {
 246         hammer2_xop_strategy_t *xop;
 247         struct buf *bp;
 248         struct bio *bio;
 249         struct bio *nbio;
 250         hammer2_inode_t *ip;
 251         hammer2_key_t lbase;
 252
 253         bio = ap->a_bio;
 254         bp = bio->bio_buf;
 255         ip = VTOI(ap->a_vp);
 256         nbio = push_bio(bio);
 257
 258         lbase = bio->bio_offset;
 259         KKASSERT(((int)lbase & HAMMER2_PBUFMASK) == 0);
 260
 261         xop = hammer2_xop_alloc(ip, 0);
 262         xop->finished = 0;
 263         xop->bio = bio;
 264         xop->lbase = lbase;
 265         hammer2_mtx_init(&xop->lock, "h2bior");
 266         hammer2_xop_start(&xop->head, hammer2_strategy_xop_read);
 267         /* asynchronous completion */
 268
 269         return(0);
 270 }
 271
 272 /*
 273  * Per-node XOP (threaded), do a synchronous lookup of the chain and
 274  * its data.  The frontend is asynchronous, so we are also responsible
 275  * for racing to terminate the frontend.
 276  */
 277 static
 278 void
 279 hammer2_strategy_xop_read(hammer2_xop_t *arg, int clindex)
 280 {
 281         hammer2_xop_strategy_t *xop = &arg->xop_strategy;
 282         hammer2_chain_t *parent;
 283         hammer2_chain_t *chain;
 284         hammer2_key_t key_dummy;
 285         hammer2_key_t lbase;
 286         struct bio *bio;
 287         struct buf *bp;
 288         int cache_index = -1;
 289         int error;
 290
 291         lbase = xop->lbase;
 292         bio = xop->bio;
 293         bp = bio->bio_buf;
 294
 295         parent = hammer2_inode_chain(xop->head.ip1, clindex,
 296                                      HAMMER2_RESOLVE_ALWAYS |
 297                                      HAMMER2_RESOLVE_SHARED);
 298         if (parent) {
 299                 chain = hammer2_chain_lookup(&parent, &key_dummy,
 300                                              lbase, lbase,
 301                                              &cache_index,
 302                                              HAMMER2_LOOKUP_ALWAYS |
 303                                              HAMMER2_LOOKUP_SHARED);
 304                 error = chain ? chain->error : 0;
 305         } else {
 306                 error = EIO;
 307                 chain = NULL;
 308         }
 309         error = hammer2_xop_feed(&xop->head, chain, clindex, error);
 310         if (chain) {
 311                 hammer2_chain_unlock(chain);
 312                 hammer2_chain_drop(chain);
 313         }
 314         if (parent) {
 315                 hammer2_chain_unlock(parent);
 316                 hammer2_chain_drop(parent);
 317         }
 318         chain = NULL;   /* safety */
 319         parent = NULL;  /* safety */
 320
 321         /*
 322          * Race to finish the frontend
 323          */
 324         if (xop->finished)
 325                 return;
 326         hammer2_mtx_ex(&xop->lock);
 327         if (xop->finished) {
 328                 hammer2_mtx_unlock(&xop->lock);
 329                 return;
 330         }
 331
 332         /*
 333          * Async operation has not completed and we now own the lock.
 334          * Determine if we can complete the operation by issuing the
 335          * frontend collection non-blocking.
 336          */
 337         error = hammer2_xop_collect(&xop->head, HAMMER2_XOP_COLLECT_NOWAIT);
 338
 339         switch(error) {
 340         case 0:
 341                 xop->finished = 1;
 342                 hammer2_mtx_unlock(&xop->lock);
 343                 chain = xop->head.cluster.focus;
 344                 hammer2_strategy_read_completion(chain, (char *)chain->data,
 345                                                  xop->bio);
 346                 hammer2_xop_retire(&xop->head, HAMMER2_XOPMASK_VOP);
 347                 biodone(bio);
 348                 break;
 349         case ENOENT:
 350                 xop->finished = 1;
 351                 hammer2_mtx_unlock(&xop->lock);
 352                 bp->b_resid = 0;
 353                 bp->b_error = 0;
 354                 bzero(bp->b_data, bp->b_bcount);
 355                 biodone(bio);
 356                 hammer2_xop_retire(&xop->head, HAMMER2_XOPMASK_VOP);
 357                 break;
 358         case EINPROGRESS:
 359                 hammer2_mtx_unlock(&xop->lock);
 360                 break;
 361         default:
 362                 xop->finished = 1;
 363                 hammer2_mtx_unlock(&xop->lock);
 364                 bp->b_flags |= B_ERROR;
 365                 bp->b_error = EIO;
 366                 biodone(bio);
 367                 hammer2_xop_retire(&xop->head, HAMMER2_XOPMASK_VOP);
 368                 break;
 369         }
 370 }
 371
 372 static
 373 void
 374 hammer2_strategy_read_completion(hammer2_chain_t *chain, char *data,
 375                                  struct bio *bio)
 376 {
 377         struct buf *bp = bio->bio_buf;
 378
 379         if (chain->bref.type == HAMMER2_BREF_TYPE_INODE) {
 380                 /*
 381                  * Data is embedded in the inode (copy from inode).
 382                  */
 383                 bcopy(((hammer2_inode_data_t *)data)->u.data,
 384                       bp->b_data, HAMMER2_EMBEDDED_BYTES);
 385                 bzero(bp->b_data + HAMMER2_EMBEDDED_BYTES,
 386                       bp->b_bcount - HAMMER2_EMBEDDED_BYTES);
 387                 bp->b_resid = 0;
 388                 bp->b_error = 0;
 389         } else if (chain->bref.type == HAMMER2_BREF_TYPE_DATA) {
 390                 /*
 391                  * Data is on-media, record for live dedup.
 392                  */
 393                 hammer2_dedup_record(chain, data);
 394
 395                 /*
 396                  * Decopmression and copy.
 397                  */
 398                 switch (HAMMER2_DEC_COMP(chain->bref.methods)) {
 399                 case HAMMER2_COMP_LZ4:
 400                         hammer2_decompress_LZ4_callback(data, chain->bytes,
 401                                                         bio);
 402                         break;
 403                 case HAMMER2_COMP_ZLIB:
 404                         hammer2_decompress_ZLIB_callback(data, chain->bytes,
 405                                                          bio);
 406                         break;
 407                 case HAMMER2_COMP_NONE:
 408                         KKASSERT(chain->bytes <= bp->b_bcount);
 409                         bcopy(data, bp->b_data, chain->bytes);
 410                         if (chain->bytes < bp->b_bcount) {
 411                                 bzero(bp->b_data + chain->bytes,
 412                                       bp->b_bcount - chain->bytes);
 413                         }
 414                         bp->b_flags |= B_NOTMETA;
 415                         bp->b_resid = 0;
 416                         bp->b_error = 0;
 417                         break;
 418                 default:
 419                         panic("hammer2_strategy_read: "
 420                               "unknown compression type");
 421                 }
 422         } else {
 423                 panic("hammer2_strategy_read: unknown bref type");
 424         }
 425 }
 426
 427 /****************************************************************************
 428  *                              WRITE SUPPORT                               *
 429  ****************************************************************************/
 430
 431 /*
 432  * Functions for compression in threads,
 433  * from hammer2_vnops.c
 434  */
 435 static void hammer2_write_file_core(struct buf *bp, hammer2_inode_t *ip,
 436                                 hammer2_chain_t **parentp,
 437                                 hammer2_key_t lbase, int ioflag, int pblksize,
 438                                 hammer2_tid_t mtid, int *errorp);
 439 static void hammer2_compress_and_write(struct buf *bp, hammer2_inode_t *ip,
 440                                 hammer2_chain_t **parentp,
 441                                 hammer2_key_t lbase, int ioflag, int pblksize,
 442                                 hammer2_tid_t mtid, int *errorp,
 443                                 int comp_algo, int check_algo);
 444 static void hammer2_zero_check_and_write(struct buf *bp, hammer2_inode_t *ip,
 445                                 hammer2_chain_t **parentp,
 446                                 hammer2_key_t lbase, int ioflag, int pblksize,
 447                                 hammer2_tid_t mtid, int *errorp,
 448                                 int check_algo);
 449 static int test_block_zeros(const char *buf, size_t bytes);
 450 static void zero_write(struct buf *bp, hammer2_inode_t *ip,
 451                                 hammer2_chain_t **parentp,
 452                                 hammer2_key_t lbase,
 453                                 hammer2_tid_t mtid, int *errorp);
 454 static void hammer2_write_bp(hammer2_chain_t *chain, struct buf *bp,
 455                                 int ioflag, int pblksize,
 456                                 hammer2_tid_t mtid, int *errorp,
 457                                 int check_algo);
 458
 459 static
 460 int
 461 hammer2_strategy_write(struct vop_strategy_args *ap)
 462 {
 463         hammer2_xop_strategy_t *xop;
 464         hammer2_pfs_t *pmp;
 465         struct bio *bio;
 466         struct buf *bp;
 467         hammer2_inode_t *ip;
 468
 469         bio = ap->a_bio;
 470         bp = bio->bio_buf;
 471         ip = VTOI(ap->a_vp);
 472         pmp = ip->pmp;
 473
 474         hammer2_lwinprog_ref(pmp);
 475         hammer2_trans_assert_strategy(pmp);
 476
 477         xop = hammer2_xop_alloc(ip, HAMMER2_XOP_MODIFYING);
 478         xop->finished = 0;
 479         xop->bio = bio;
 480         xop->lbase = bio->bio_offset;
 481         hammer2_mtx_init(&xop->lock, "h2biow");
 482         hammer2_xop_start(&xop->head, hammer2_strategy_xop_write);
 483         /* asynchronous completion */
 484
 485         hammer2_lwinprog_wait(pmp, hammer2_flush_pipe);
 486
 487         return(0);
 488 }
 489
 490 /*
 491  * Per-node XOP (threaded).  Write the logical buffer to the media.
 492  */
 493 static
 494 void
 495 hammer2_strategy_xop_write(hammer2_xop_t *arg, int clindex)
 496 {
 497         hammer2_xop_strategy_t *xop = &arg->xop_strategy;
 498         hammer2_chain_t *parent;
 499         hammer2_key_t lbase;
 500         hammer2_inode_t *ip;
 501         struct bio *bio;
 502         struct buf *bp;
 503         int error;
 504         int lblksize;
 505         int pblksize;
 506
 507         lbase = xop->lbase;
 508         bio = xop->bio;
 509         bp = bio->bio_buf;
 510         ip = xop->head.ip1;
 511
 512         /* hammer2_trans_init(parent->hmp->spmp, HAMMER2_TRANS_BUFCACHE); */
 513
 514         lblksize = hammer2_calc_logical(ip, bio->bio_offset, &lbase, NULL);
 515         pblksize = hammer2_calc_physical(ip, lbase);
 516         parent = hammer2_inode_chain(ip, clindex, HAMMER2_RESOLVE_ALWAYS);
 517         hammer2_write_file_core(bp, ip, &parent,
 518                                 lbase, IO_ASYNC, pblksize,
 519                                 xop->head.mtid, &error);
 520         if (parent) {
 521                 hammer2_chain_unlock(parent);
 522                 hammer2_chain_drop(parent);
 523                 parent = NULL;  /* safety */
 524         }
 525         error = hammer2_xop_feed(&xop->head, NULL, clindex, error);
 526
 527         /*
 528          * Race to finish the frontend
 529          */
 530         if (xop->finished)
 531                 return;
 532         hammer2_mtx_ex(&xop->lock);
 533         if (xop->finished) {
 534                 hammer2_mtx_unlock(&xop->lock);
 535                 return;
 536         }
 537
 538         /*
 539          * Async operation has not completed and we now own the lock.
 540          * Determine if we can complete the operation by issuing the
 541          * frontend collection non-blocking.
 542          */
 543         error = hammer2_xop_collect(&xop->head, HAMMER2_XOP_COLLECT_NOWAIT);
 544
 545         switch(error) {
 546         case ENOENT:
 547         case 0:
 548                 xop->finished = 1;
 549                 hammer2_mtx_unlock(&xop->lock);
 550                 bp->b_resid = 0;
 551                 bp->b_error = 0;
 552                 biodone(bio);
 553                 hammer2_xop_retire(&xop->head, HAMMER2_XOPMASK_VOP);
 554                 hammer2_lwinprog_drop(ip->pmp);
 555                 break;
 556         case EINPROGRESS:
 557                 hammer2_mtx_unlock(&xop->lock);
 558                 break;
 559         default:
 560                 xop->finished = 1;
 561                 hammer2_mtx_unlock(&xop->lock);
 562                 bp->b_flags |= B_ERROR;
 563                 bp->b_error = EIO;
 564                 biodone(bio);
 565                 hammer2_xop_retire(&xop->head, HAMMER2_XOPMASK_VOP);
 566                 hammer2_lwinprog_drop(ip->pmp);
 567                 break;
 568         }
 569 }
 570
 571 /*
 572  * Wait for pending I/O to complete
 573  */
 574 void
 575 hammer2_bioq_sync(hammer2_pfs_t *pmp)
 576 {
 577         hammer2_lwinprog_wait(pmp, 0);
 578 }
 579
 580 /*
 581  * Create a new cluster at (cparent, lbase) and assign physical storage,
 582  * returning a cluster suitable for I/O.  The cluster will be in a modified
 583  * state.
 584  *
 585  * cparent can wind up being anything.
 586  *
 587  * If datap is not NULL, *datap points to the real data we intend to write.
 588  * If we can dedup the storage location we set *datap to NULL to indicate
 589  * to the caller that a dedup occurred.
 590  *
 591  * NOTE: Special case for data embedded in inode.
 592  */
 593 static
 594 hammer2_chain_t *
 595 hammer2_assign_physical(hammer2_inode_t *ip, hammer2_chain_t **parentp,
 596                         hammer2_key_t lbase, int pblksize,
 597                         hammer2_tid_t mtid, char **datap, int *errorp)
 598 {
 599         hammer2_chain_t *chain;
 600         hammer2_key_t key_dummy;
 601         hammer2_off_t dedup_off;
 602         int pradix = hammer2_getradix(pblksize);
 603         int cache_index = -1;
 604
 605         /*
 606          * Locate the chain associated with lbase, return a locked chain.
 607          * However, do not instantiate any data reference (which utilizes a
 608          * device buffer) because we will be using direct IO via the
 609          * logical buffer cache buffer.
 610          */
 611         *errorp = 0;
 612         KKASSERT(pblksize >= HAMMER2_ALLOC_MIN);
 613 retry:
 614         chain = hammer2_chain_lookup(parentp, &key_dummy,
 615                                      lbase, lbase,
 616                                      &cache_index,
 617                                      HAMMER2_LOOKUP_NODATA);
 618         if (chain == NULL) {
 619                 /*
 620                  * We found a hole, create a new chain entry.
 621                  *
 622                  * NOTE: DATA chains are created without device backing
 623                  *       store (nor do we want any).
 624                  */
 625                 dedup_off = hammer2_dedup_lookup((*parentp)->hmp, datap,
 626                                                  pblksize);
 627                 *errorp = hammer2_chain_create(parentp, &chain, ip->pmp,
 628                                                lbase, HAMMER2_PBUFRADIX,
 629                                                HAMMER2_BREF_TYPE_DATA,
 630                                                pblksize, mtid,
 631                                                dedup_off, 0);
 632                 if (chain == NULL) {
 633                         panic("hammer2_chain_create: par=%p error=%d\n",
 634                               *parentp, *errorp);
 635                         goto retry;
 636                 }
 637                 /*ip->delta_dcount += pblksize;*/
 638         } else {
 639                 switch (chain->bref.type) {
 640                 case HAMMER2_BREF_TYPE_INODE:
 641                         /*
 642                          * The data is embedded in the inode, which requires
 643                          * a bit more finess.
 644                          */
 645                         hammer2_chain_modify_ip(ip, chain, mtid, 0);
 646                         break;
 647                 case HAMMER2_BREF_TYPE_DATA:
 648                         dedup_off = hammer2_dedup_lookup(chain->hmp, datap,
 649                                                          pblksize);
 650                         if (chain->bytes != pblksize) {
 651                                 hammer2_chain_resize(ip, *parentp, chain,
 652                                                      mtid, dedup_off,
 653                                                      pradix,
 654                                                      HAMMER2_MODIFY_OPTDATA);
 655                         }
 656
 657                         /*
 658                          * DATA buffers must be marked modified whether the
 659                          * data is in a logical buffer or not.  We also have
 660                          * to make this call to fixup the chain data pointers
 661                          * after resizing in case this is an encrypted or
 662                          * compressed buffer.
 663                          */
 664                         hammer2_chain_modify(chain, mtid, dedup_off,
 665                                              HAMMER2_MODIFY_OPTDATA);
 666                         break;
 667                 default:
 668                         panic("hammer2_assign_physical: bad type");
 669                         /* NOT REACHED */
 670                         break;
 671                 }
 672         }
 673         return (chain);
 674 }
 675
 676 /*
 677  * hammer2_write_file_core() - hammer2_write_thread() helper
 678  *
 679  * The core write function which determines which path to take
 680  * depending on compression settings.  We also have to locate the
 681  * related chains so we can calculate and set the check data for
 682  * the blockref.
 683  */
 684 static
 685 void
 686 hammer2_write_file_core(struct buf *bp, hammer2_inode_t *ip,
 687                         hammer2_chain_t **parentp,
 688                         hammer2_key_t lbase, int ioflag, int pblksize,
 689                         hammer2_tid_t mtid, int *errorp)
 690 {
 691         hammer2_chain_t *chain;
 692         char *data = bp->b_data;
 693
 694         switch(HAMMER2_DEC_ALGO(ip->meta.comp_algo)) {
 695         case HAMMER2_COMP_NONE:
 696                 /*
 697                  * We have to assign physical storage to the buffer
 698                  * we intend to dirty or write now to avoid deadlocks
 699                  * in the strategy code later.
 700                  *
 701                  * This can return NOOFFSET for inode-embedded data.
 702                  * The strategy code will take care of it in that case.
 703                  */
 704                 chain = hammer2_assign_physical(ip, parentp, lbase, pblksize,
 705                                                 mtid, &data, errorp);
 706                 if (chain->bref.type == HAMMER2_BREF_TYPE_INODE) {
 707                         hammer2_inode_data_t *wipdata;
 708
 709                         wipdata = &chain->data->ipdata;
 710                         KKASSERT(wipdata->meta.op_flags &
 711                                  HAMMER2_OPFLAG_DIRECTDATA);
 712                         KKASSERT(bp->b_loffset == 0);
 713                         bcopy(bp->b_data, wipdata->u.data,
 714                               HAMMER2_EMBEDDED_BYTES);
 715                         ++hammer2_iod_file_wembed;
 716                 } else if (data == NULL) {
 717                         /*
 718                          * Copy of data already present on-media.
 719                          */
 720                         chain->bref.methods =
 721                                 HAMMER2_ENC_COMP(HAMMER2_COMP_NONE) +
 722                                 HAMMER2_ENC_CHECK(ip->meta.check_algo);
 723                         hammer2_chain_setcheck(chain, bp->b_data);
 724                 } else {
 725                         hammer2_write_bp(chain, bp, ioflag, pblksize,
 726                                          mtid, errorp, ip->meta.check_algo);
 727                 }
 728                 if (chain) {
 729                         hammer2_chain_unlock(chain);
 730                         hammer2_chain_drop(chain);
 731                 }
 732                 break;
 733         case HAMMER2_COMP_AUTOZERO:
 734                 /*
 735                  * Check for zero-fill only
 736                  */
 737                 hammer2_zero_check_and_write(bp, ip, parentp,
 738                                              lbase, ioflag, pblksize,
 739                                              mtid, errorp,
 740                                              ip->meta.check_algo);
 741                 break;
 742         case HAMMER2_COMP_LZ4:
 743         case HAMMER2_COMP_ZLIB:
 744         default:
 745                 /*
 746                  * Check for zero-fill and attempt compression.
 747                  */
 748                 hammer2_compress_and_write(bp, ip, parentp,
 749                                            lbase, ioflag, pblksize,
 750                                            mtid, errorp,
 751                                            ip->meta.comp_algo,
 752                                            ip->meta.check_algo);
 753                 break;
 754         }
 755 }
 756
 757 /*
 758  * Helper
 759  *
 760  * Generic function that will perform the compression in compression
 761  * write path. The compression algorithm is determined by the settings
 762  * obtained from inode.
 763  */
 764 static
 765 void
 766 hammer2_compress_and_write(struct buf *bp, hammer2_inode_t *ip,
 767         hammer2_chain_t **parentp,
 768         hammer2_key_t lbase, int ioflag, int pblksize,
 769         hammer2_tid_t mtid, int *errorp, int comp_algo, int check_algo)
 770 {
 771         hammer2_chain_t *chain;
 772         int comp_size;
 773         int comp_block_size;
 774         char *comp_buffer;
 775         char *data;
 776
 777         if (test_block_zeros(bp->b_data, pblksize)) {
 778                 zero_write(bp, ip, parentp, lbase, mtid, errorp);
 779                 return;
 780         }
 781
 782         comp_size = 0;
 783         comp_buffer = NULL;
 784
 785         KKASSERT(pblksize / 2 <= 32768);
 786
 787         if (ip->comp_heuristic < 8 || (ip->comp_heuristic & 7) == 0) {
 788                 z_stream strm_compress;
 789                 int comp_level;
 790                 int ret;
 791
 792                 switch(HAMMER2_DEC_ALGO(comp_algo)) {
 793                 case HAMMER2_COMP_LZ4:
 794                         comp_buffer = objcache_get(cache_buffer_write,
 795                                                    M_INTWAIT);
 796                         comp_size = LZ4_compress_limitedOutput(
 797                                         bp->b_data,
 798                                         &comp_buffer[sizeof(int)],
 799                                         pblksize,
 800                                         pblksize / 2 - sizeof(int));
 801                         /*
 802                          * We need to prefix with the size, LZ4
 803                          * doesn't do it for us.  Add the related
 804                          * overhead.
 805                          */
 806                         *(int *)comp_buffer = comp_size;
 807                         if (comp_size)
 808                                 comp_size += sizeof(int);
 809                         break;
 810                 case HAMMER2_COMP_ZLIB:
 811                         comp_level = HAMMER2_DEC_LEVEL(comp_algo);
 812                         if (comp_level == 0)
 813                                 comp_level = 6; /* default zlib compression */
 814                         else if (comp_level < 6)
 815                                 comp_level = 6;
 816                         else if (comp_level > 9)
 817                                 comp_level = 9;
 818                         ret = deflateInit(&strm_compress, comp_level);
 819                         if (ret != Z_OK) {
 820                                 kprintf("HAMMER2 ZLIB: fatal error "
 821                                         "on deflateInit.\n");
 822                         }
 823
 824                         comp_buffer = objcache_get(cache_buffer_write,
 825                                                    M_INTWAIT);
 826                         strm_compress.next_in = bp->b_data;
 827                         strm_compress.avail_in = pblksize;
 828                         strm_compress.next_out = comp_buffer;
 829                         strm_compress.avail_out = pblksize / 2;
 830                         ret = deflate(&strm_compress, Z_FINISH);
 831                         if (ret == Z_STREAM_END) {
 832                                 comp_size = pblksize / 2 -
 833                                             strm_compress.avail_out;
 834                         } else {
 835                                 comp_size = 0;
 836                         }
 837                         ret = deflateEnd(&strm_compress);
 838                         break;
 839                 default:
 840                         kprintf("Error: Unknown compression method.\n");
 841                         kprintf("Comp_method = %d.\n", comp_algo);
 842                         break;
 843                 }
 844         }
 845
 846         if (comp_size == 0) {
 847                 /*
 848                  * compression failed or turned off
 849                  */
 850                 comp_block_size = pblksize;     /* safety */
 851                 if (++ip->comp_heuristic > 128)
 852                         ip->comp_heuristic = 8;
 853         } else {
 854                 /*
 855                  * compression succeeded
 856                  */
 857                 ip->comp_heuristic = 0;
 858                 if (comp_size <= 1024) {
 859                         comp_block_size = 1024;
 860                 } else if (comp_size <= 2048) {
 861                         comp_block_size = 2048;
 862                 } else if (comp_size <= 4096) {
 863                         comp_block_size = 4096;
 864                 } else if (comp_size <= 8192) {
 865                         comp_block_size = 8192;
 866                 } else if (comp_size <= 16384) {
 867                         comp_block_size = 16384;
 868                 } else if (comp_size <= 32768) {
 869                         comp_block_size = 32768;
 870                 } else {
 871                         panic("hammer2: WRITE PATH: "
 872                               "Weird comp_size value.");
 873                         /* NOT REACHED */
 874                         comp_block_size = pblksize;
 875                 }
 876
 877                 /*
 878                  * Must zero the remainder or dedup (which operates on a
 879                  * physical block basis) will not find matches.
 880                  */
 881                 if (comp_size < comp_block_size) {
 882                         bzero(comp_buffer + comp_size,
 883                               comp_block_size - comp_size);
 884                 }
 885         }
 886
 887         /*
 888          * Assign physical storage, data will be set to NULL if a live-dedup
 889          * was successful.
 890          */
 891         data = comp_size ? comp_buffer : bp->b_data;
 892         chain = hammer2_assign_physical(ip, parentp, lbase, comp_block_size,
 893                                         mtid, &data, errorp);
 894
 895         if (*errorp) {
 896                 kprintf("WRITE PATH: An error occurred while "
 897                         "assigning physical space.\n");
 898                 KKASSERT(chain == NULL);
 899                 goto done;
 900         }
 901
 902         if (chain->bref.type == HAMMER2_BREF_TYPE_INODE) {
 903                 hammer2_inode_data_t *wipdata;
 904
 905                 hammer2_chain_modify_ip(ip, chain, mtid, 0);
 906                 wipdata = &chain->data->ipdata;
 907                 KKASSERT(wipdata->meta.op_flags & HAMMER2_OPFLAG_DIRECTDATA);
 908                 KKASSERT(bp->b_loffset == 0);
 909                 bcopy(bp->b_data, wipdata->u.data, HAMMER2_EMBEDDED_BYTES);
 910                 ++hammer2_iod_file_wembed;
 911         } else if (data == NULL) {
 912                 /*
 913                  * Live deduplication, a copy of the data is already present
 914                  * on the media.
 915                  */
 916                 char *bdata;
 917
 918                 if (comp_size) {
 919                         chain->bref.methods =
 920                                 HAMMER2_ENC_COMP(comp_algo) +
 921                                 HAMMER2_ENC_CHECK(check_algo);
 922                 } else {
 923                         chain->bref.methods =
 924                                 HAMMER2_ENC_COMP(
 925                                         HAMMER2_COMP_NONE) +
 926                                 HAMMER2_ENC_CHECK(check_algo);
 927                 }
 928                 bdata = comp_size ? comp_buffer : bp->b_data;
 929                 hammer2_chain_setcheck(chain, bdata);
 930                 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_INITIAL);
 931         } else {
 932                 hammer2_io_t *dio;
 933                 char *bdata;
 934
 935                 KKASSERT(chain->flags & HAMMER2_CHAIN_MODIFIED);
 936
 937                 switch(chain->bref.type) {
 938                 case HAMMER2_BREF_TYPE_INODE:
 939                         panic("hammer2_write_bp: unexpected inode\n");
 940                         break;
 941                 case HAMMER2_BREF_TYPE_DATA:
 942                         /*
 943                          * Optimize out the read-before-write
 944                          * if possible.
 945                          */
 946                         *errorp = hammer2_io_newnz(chain->hmp,
 947                                                    chain->bref.data_off,
 948                                                    chain->bytes,
 949                                                    &dio);
 950                         if (*errorp) {
 951                                 hammer2_io_brelse(&dio);
 952                                 kprintf("hammer2: WRITE PATH: "
 953                                         "dbp bread error\n");
 954                                 break;
 955                         }
 956                         bdata = hammer2_io_data(dio, chain->bref.data_off);
 957
 958                         /*
 959                          * When loading the block make sure we don't
 960                          * leave garbage after the compressed data.
 961                          */
 962                         if (comp_size) {
 963                                 chain->bref.methods =
 964                                         HAMMER2_ENC_COMP(comp_algo) +
 965                                         HAMMER2_ENC_CHECK(check_algo);
 966                                 bcopy(comp_buffer, bdata, comp_size);
 967                         } else {
 968                                 chain->bref.methods =
 969                                         HAMMER2_ENC_COMP(
 970                                                 HAMMER2_COMP_NONE) +
 971                                         HAMMER2_ENC_CHECK(check_algo);
 972                                 bcopy(bp->b_data, bdata, pblksize);
 973                         }
 974
 975                         /*
 976                          * The flush code doesn't calculate check codes for
 977                          * file data (doing so can result in excessive I/O),
 978                          * so we do it here.
 979                          *
 980                          * Record for dedup only after the DIO's buffer cache
 981                          * buffer has been updated.
 982                          */
 983                         hammer2_chain_setcheck(chain, bdata);
 984                         hammer2_dedup_record(chain, bdata);
 985
 986                         /*
 987                          * Device buffer is now valid, chain is no longer in
 988                          * the initial state.
 989                          *
 990                          * (No blockref table worries with file data)
 991                          */
 992                         atomic_clear_int(&chain->flags, HAMMER2_CHAIN_INITIAL);
 993
 994                         /* Now write the related bdp. */
 995                         if (ioflag & IO_SYNC) {
 996                                 /*
 997                                  * Synchronous I/O requested.
 998                                  */
 999                                 hammer2_io_bwrite(&dio);
1000                         /*
1001                         } else if ((ioflag & IO_DIRECT) &&
1002                                    loff + n == pblksize) {
1003                                 hammer2_io_bdwrite(&dio);
1004                         */
1005                         } else if (ioflag & IO_ASYNC) {
1006                                 hammer2_io_bawrite(&dio);
1007                         } else {
1008                                 hammer2_io_bdwrite(&dio);
1009                         }
1010                         break;
1011                 default:
1012                         panic("hammer2_write_bp: bad chain type %d\n",
1013                                 chain->bref.type);
1014                         /* NOT REACHED */
1015                         break;
1016                 }
1017         }
1018 done:
1019         if (chain) {
1020                 hammer2_chain_unlock(chain);
1021                 hammer2_chain_drop(chain);
1022         }
1023         if (comp_buffer)
1024                 objcache_put(cache_buffer_write, comp_buffer);
1025 }
1026
1027 /*
1028  * Helper
1029  *
1030  * Function that performs zero-checking and writing without compression,
1031  * it corresponds to default zero-checking path.
1032  */
1033 static
1034 void
1035 hammer2_zero_check_and_write(struct buf *bp, hammer2_inode_t *ip,
1036         hammer2_chain_t **parentp,
1037         hammer2_key_t lbase, int ioflag, int pblksize,
1038         hammer2_tid_t mtid, int *errorp,
1039         int check_algo)
1040 {
1041         hammer2_chain_t *chain;
1042         char *data = bp->b_data;
1043
1044         if (test_block_zeros(bp->b_data, pblksize)) {
1045                 zero_write(bp, ip, parentp, lbase, mtid, errorp);
1046         } else {
1047                 chain = hammer2_assign_physical(ip, parentp, lbase, pblksize,
1048                                                 mtid, &data, errorp);
1049                 if (data) {
1050                         hammer2_write_bp(chain, bp, ioflag, pblksize,
1051                                          mtid, errorp, check_algo);
1052                 } /* else dedup occurred */
1053                 if (chain) {
1054                         hammer2_chain_unlock(chain);
1055                         hammer2_chain_drop(chain);
1056                 }
1057         }
1058 }
1059
1060 /*
1061  * Helper
1062  *
1063  * A function to test whether a block of data contains only zeros,
1064  * returns TRUE (non-zero) if the block is all zeros.
1065  */
1066 static
1067 int
1068 test_block_zeros(const char *buf, size_t bytes)
1069 {
1070         size_t i;
1071
1072         for (i = 0; i < bytes; i += sizeof(long)) {
1073                 if (*(const long *)(buf + i) != 0)
1074                         return (0);
1075         }
1076         return (1);
1077 }
1078
1079 /*
1080  * Helper
1081  *
1082  * Function to "write" a block that contains only zeros.
1083  */
1084 static
1085 void
1086 zero_write(struct buf *bp, hammer2_inode_t *ip,
1087            hammer2_chain_t **parentp,
1088            hammer2_key_t lbase, hammer2_tid_t mtid, int *errorp __unused)
1089 {
1090         hammer2_chain_t *chain;
1091         hammer2_key_t key_dummy;
1092         int cache_index = -1;
1093
1094         chain = hammer2_chain_lookup(parentp, &key_dummy,
1095                                      lbase, lbase,
1096                                      &cache_index,
1097                                      HAMMER2_LOOKUP_NODATA);
1098         if (chain) {
1099                 if (chain->bref.type == HAMMER2_BREF_TYPE_INODE) {
1100                         hammer2_inode_data_t *wipdata;
1101
1102                         hammer2_chain_modify_ip(ip, chain, mtid, 0);
1103                         wipdata = &chain->data->ipdata;
1104                         KKASSERT(wipdata->meta.op_flags &
1105                                  HAMMER2_OPFLAG_DIRECTDATA);
1106                         KKASSERT(bp->b_loffset == 0);
1107                         bzero(wipdata->u.data, HAMMER2_EMBEDDED_BYTES);
1108                         ++hammer2_iod_file_wembed;
1109                 } else {
1110                         hammer2_chain_delete(*parentp, chain,
1111                                              mtid, HAMMER2_DELETE_PERMANENT);
1112                         ++hammer2_iod_file_wzero;
1113                 }
1114                 hammer2_chain_unlock(chain);
1115                 hammer2_chain_drop(chain);
1116         } else {
1117                 ++hammer2_iod_file_wzero;
1118         }
1119 }
1120
1121 /*
1122  * Helper
1123  *
1124  * Function to write the data as it is, without performing any sort of
1125  * compression. This function is used in path without compression and
1126  * default zero-checking path.
1127  */
1128 static
1129 void
1130 hammer2_write_bp(hammer2_chain_t *chain, struct buf *bp, int ioflag,
1131                  int pblksize,
1132                  hammer2_tid_t mtid, int *errorp, int check_algo)
1133 {
1134         hammer2_inode_data_t *wipdata;
1135         hammer2_io_t *dio;
1136         char *bdata;
1137         int error;
1138
1139         error = 0;      /* XXX TODO below */
1140
1141         KKASSERT(chain->flags & HAMMER2_CHAIN_MODIFIED);
1142
1143         switch(chain->bref.type) {
1144         case HAMMER2_BREF_TYPE_INODE:
1145                 wipdata = &chain->data->ipdata;
1146                 KKASSERT(wipdata->meta.op_flags & HAMMER2_OPFLAG_DIRECTDATA);
1147                 KKASSERT(bp->b_loffset == 0);
1148                 bcopy(bp->b_data, wipdata->u.data, HAMMER2_EMBEDDED_BYTES);
1149                 error = 0;
1150                 ++hammer2_iod_file_wembed;
1151                 break;
1152         case HAMMER2_BREF_TYPE_DATA:
1153                 error = hammer2_io_newnz(chain->hmp,
1154                                          chain->bref.data_off,
1155                                          chain->bytes, &dio);
1156                 if (error) {
1157                         hammer2_io_bqrelse(&dio);
1158                         kprintf("hammer2: WRITE PATH: "
1159                                 "dbp bread error\n");
1160                         break;
1161                 }
1162                 bdata = hammer2_io_data(dio, chain->bref.data_off);
1163
1164                 chain->bref.methods = HAMMER2_ENC_COMP(HAMMER2_COMP_NONE) +
1165                                       HAMMER2_ENC_CHECK(check_algo);
1166                 bcopy(bp->b_data, bdata, chain->bytes);
1167
1168                 /*
1169                  * The flush code doesn't calculate check codes for
1170                  * file data (doing so can result in excessive I/O),
1171                  * so we do it here.
1172                  *
1173                  * Record for dedup only after the DIO's buffer cache
1174                  * buffer has been updated.
1175                  */
1176                 hammer2_chain_setcheck(chain, bdata);
1177                 hammer2_dedup_record(chain, bdata);
1178
1179                 /*
1180                  * Device buffer is now valid, chain is no longer in
1181                  * the initial state.
1182                  *
1183                  * (No blockref table worries with file data)
1184                  */
1185                 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_INITIAL);
1186
1187                 if (ioflag & IO_SYNC) {
1188                         /*
1189                          * Synchronous I/O requested.
1190                          */
1191                         hammer2_io_bwrite(&dio);
1192                 /*
1193                 } else if ((ioflag & IO_DIRECT) &&
1194                            loff + n == pblksize) {
1195                         hammer2_io_bdwrite(&dio);
1196                 */
1197                 } else if (ioflag & IO_ASYNC) {
1198                         hammer2_io_bawrite(&dio);
1199                 } else {
1200                         hammer2_io_bdwrite(&dio);
1201                 }
1202                 break;
1203         default:
1204                 panic("hammer2_write_bp: bad chain type %d\n",
1205                       chain->bref.type);
1206                 /* NOT REACHED */
1207                 error = 0;
1208                 break;
1209         }
1210         KKASSERT(error == 0);   /* XXX TODO */
1211         *errorp = error;
1212 }
1213
1214 /*
1215  * LIVE DEDUP HEURISTIC
1216  *
1217  * WARNING! This code is SMP safe but the heuristic allows SMP collisions.
1218  *          All fields must be loaded into locals and validated.
1219  */
1220 static
1221 void
1222 hammer2_dedup_record(hammer2_chain_t *chain, char *data)
1223 {
1224         hammer2_dev_t *hmp;
1225         hammer2_dedup_t *dedup;
1226         int32_t crc;
1227         int best = 0;
1228         int i;
1229         int dticks;
1230
1231         hmp = chain->hmp;
1232         crc = hammer2_icrc32(data, chain->bytes);
1233         dedup = &hmp->heur_dedup[crc & (HAMMER2_DEDUP_HEUR_MASK & ~3)];
1234         for (i = 0; i < 4; ++i) {
1235                 if (dedup[i].data_crc == crc) {
1236                         best = i;
1237                         break;
1238                 }
1239                 dticks = (int)(dedup[i].ticks - dedup[best].ticks);
1240                 if (dticks < 0 || dticks > hz * 60 * 30)
1241                         best = i;
1242         }
1243         dedup += best;
1244         if (hammer2_debug & 0x40000) {
1245                 kprintf("REC %04x %08x %016jx\n",
1246                         (int)(dedup - hmp->heur_dedup),
1247                         crc,
1248                         chain->bref.data_off);
1249         }
1250         dedup->ticks = ticks;
1251         dedup->data_off = chain->bref.data_off;
1252         dedup->data_crc = crc;
1253         atomic_set_int(&chain->flags, HAMMER2_CHAIN_DEDUP);
1254 }
1255
1256 static
1257 hammer2_off_t
1258 hammer2_dedup_lookup(hammer2_dev_t *hmp, char **datap, int pblksize)
1259 {
1260         hammer2_dedup_t *dedup;
1261         hammer2_io_t *dio;
1262         hammer2_off_t off;
1263         uint32_t crc;
1264         char *data;
1265         int i;
1266
1267         data = *datap;
1268         if (data == NULL)
1269                 return 0;
1270
1271         crc = hammer2_icrc32(data, pblksize);
1272         dedup = &hmp->heur_dedup[crc & (HAMMER2_DEDUP_HEUR_MASK & ~3)];
1273
1274         if (hammer2_debug & 0x40000) {
1275                 kprintf("LOC %04x/4 %08x\n",
1276                         (int)(dedup - hmp->heur_dedup),
1277                         crc);
1278         }
1279
1280         for (i = 0; i < 4; ++i) {
1281                 off = dedup[i].data_off;
1282                 cpu_ccfence();
1283                 if (dedup[i].data_crc != crc)
1284                         continue;
1285                 if ((1 << (int)(off & HAMMER2_OFF_MASK_RADIX)) != pblksize)
1286                         continue;
1287                 dio = hammer2_io_getquick(hmp, off, pblksize);
1288                 if (dio &&
1289                     bcmp(data, hammer2_io_data(dio, off), pblksize) == 0) {
1290                         if (hammer2_debug & 0x40000) {
1291                                 kprintf("DEDUP SUCCESS %016jx\n",
1292                                         (intmax_t)off);
1293                         }
1294                         hammer2_io_putblk(&dio);
1295                         *datap = NULL;
1296                         dedup[i].ticks = ticks; /* update use */
1297                         ++hammer2_iod_file_wdedup;
1298                         return off;             /* RETURN */
1299                 }
1300                 if (dio)
1301                         hammer2_io_putblk(&dio);
1302         }
1303         return 0;
1304 }
1305
1306 /*
1307  * Poof.  Races are ok, if someone gets in and reuses a dedup offset
1308  * before or while we are clearing it they will also recover the freemap
1309  * entry (set it to fully allocated), so a bulkfree race can only set it
1310  * to a possibly-free state.
1311  *
1312  * XXX ok, well, not really sure races are ok but going to run with it
1313  *     for the moment.
1314  */
1315 void
1316 hammer2_dedup_clear(hammer2_dev_t *hmp)
1317 {
1318         int i;
1319
1320         for (i = 0; i < HAMMER2_DEDUP_HEUR_SIZE; ++i) {
1321                 hmp->heur_dedup[i].data_off = 0;
1322                 hmp->heur_dedup[i].ticks = ticks - 1;
1323         }
1324 }