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 h2timer[32];
  94 int h2last;
  95 int h2lid;
  96
  97 #define TIMER(which)    do {                            \
  98         if (h2last)                                     \
  99                 h2timer[h2lid] += (int)(ticks - h2last);\
 100         h2last = ticks;                                 \
 101         h2lid = which;                                  \
 102 } while(0)
 103
 104 int
 105 hammer2_vop_strategy(struct vop_strategy_args *ap)
 106 {
 107         struct bio *biop;
 108         struct buf *bp;
 109         int error;
 110
 111         biop = ap->a_bio;
 112         bp = biop->bio_buf;
 113
 114         switch(bp->b_cmd) {
 115         case BUF_CMD_READ:
 116                 error = hammer2_strategy_read(ap);
 117                 ++hammer2_iod_file_read;
 118                 break;
 119         case BUF_CMD_WRITE:
 120                 error = hammer2_strategy_write(ap);
 121                 ++hammer2_iod_file_write;
 122                 break;
 123         default:
 124                 bp->b_error = error = EINVAL;
 125                 bp->b_flags |= B_ERROR;
 126                 biodone(biop);
 127                 break;
 128         }
 129         return (error);
 130 }
 131
 132 /*
 133  * Return the largest contiguous physical disk range for the logical
 134  * request, in bytes.
 135  *
 136  * (struct vnode *vp, off_t loffset, off_t *doffsetp, int *runp, int *runb)
 137  *
 138  * Basically disabled, the logical buffer write thread has to deal with
 139  * buffers one-at-a-time.  Note that this should not prevent cluster_read()
 140  * from reading-ahead, it simply prevents it from trying form a single
 141  * cluster buffer for the logical request.  H2 already uses 64KB buffers!
 142  */
 143 int
 144 hammer2_vop_bmap(struct vop_bmap_args *ap)
 145 {
 146         *ap->a_doffsetp = NOOFFSET;
 147         if (ap->a_runp)
 148                 *ap->a_runp = 0;
 149         if (ap->a_runb)
 150                 *ap->a_runb = 0;
 151         return (EOPNOTSUPP);
 152 }
 153
 154 /****************************************************************************
 155  *                              READ SUPPORT                                *
 156  ****************************************************************************/
 157 /*
 158  * Callback used in read path in case that a block is compressed with LZ4.
 159  */
 160 static
 161 void
 162 hammer2_decompress_LZ4_callback(const char *data, u_int bytes, struct bio *bio)
 163 {
 164         struct buf *bp;
 165         char *compressed_buffer;
 166         int compressed_size;
 167         int result;
 168
 169         bp = bio->bio_buf;
 170
 171 #if 0
 172         if bio->bio_caller_info2.index &&
 173               bio->bio_caller_info1.uvalue32 !=
 174               crc32(bp->b_data, bp->b_bufsize) --- return error
 175 #endif
 176
 177         KKASSERT(bp->b_bufsize <= HAMMER2_PBUFSIZE);
 178         compressed_size = *(const int *)data;
 179         KKASSERT(compressed_size <= bytes - sizeof(int));
 180
 181         compressed_buffer = objcache_get(cache_buffer_read, M_INTWAIT);
 182         result = LZ4_decompress_safe(__DECONST(char *, &data[sizeof(int)]),
 183                                      compressed_buffer,
 184                                      compressed_size,
 185                                      bp->b_bufsize);
 186         if (result < 0) {
 187                 kprintf("READ PATH: Error during decompression."
 188                         "bio %016jx/%d\n",
 189                         (intmax_t)bio->bio_offset, bytes);
 190                 /* make sure it isn't random garbage */
 191                 bzero(compressed_buffer, bp->b_bufsize);
 192         }
 193         KKASSERT(result <= bp->b_bufsize);
 194         bcopy(compressed_buffer, bp->b_data, bp->b_bufsize);
 195         if (result < bp->b_bufsize)
 196                 bzero(bp->b_data + result, bp->b_bufsize - result);
 197         objcache_put(cache_buffer_read, compressed_buffer);
 198         bp->b_resid = 0;
 199         bp->b_flags |= B_AGE;
 200 }
 201
 202 /*
 203  * Callback used in read path in case that a block is compressed with ZLIB.
 204  * It is almost identical to LZ4 callback, so in theory they can be unified,
 205  * but we didn't want to make changes in bio structure for that.
 206  */
 207 static
 208 void
 209 hammer2_decompress_ZLIB_callback(const char *data, u_int bytes, struct bio *bio)
 210 {
 211         struct buf *bp;
 212         char *compressed_buffer;
 213         z_stream strm_decompress;
 214         int result;
 215         int ret;
 216
 217         bp = bio->bio_buf;
 218
 219         KKASSERT(bp->b_bufsize <= HAMMER2_PBUFSIZE);
 220         strm_decompress.avail_in = 0;
 221         strm_decompress.next_in = Z_NULL;
 222
 223         ret = inflateInit(&strm_decompress);
 224
 225         if (ret != Z_OK)
 226                 kprintf("HAMMER2 ZLIB: Fatal error in inflateInit.\n");
 227
 228         compressed_buffer = objcache_get(cache_buffer_read, M_INTWAIT);
 229         strm_decompress.next_in = __DECONST(char *, data);
 230
 231         /* XXX supply proper size, subset of device bp */
 232         strm_decompress.avail_in = bytes;
 233         strm_decompress.next_out = compressed_buffer;
 234         strm_decompress.avail_out = bp->b_bufsize;
 235
 236         ret = inflate(&strm_decompress, Z_FINISH);
 237         if (ret != Z_STREAM_END) {
 238                 kprintf("HAMMER2 ZLIB: Fatar error during decompression.\n");
 239                 bzero(compressed_buffer, bp->b_bufsize);
 240         }
 241         bcopy(compressed_buffer, bp->b_data, bp->b_bufsize);
 242         result = bp->b_bufsize - strm_decompress.avail_out;
 243         if (result < bp->b_bufsize)
 244                 bzero(bp->b_data + result, strm_decompress.avail_out);
 245         objcache_put(cache_buffer_read, compressed_buffer);
 246         ret = inflateEnd(&strm_decompress);
 247
 248         bp->b_resid = 0;
 249         bp->b_flags |= B_AGE;
 250 }
 251
 252 /*
 253  * Logical buffer I/O, async read.
 254  */
 255 static
 256 int
 257 hammer2_strategy_read(struct vop_strategy_args *ap)
 258 {
 259         hammer2_xop_strategy_t *xop;
 260         struct buf *bp;
 261         struct bio *bio;
 262         struct bio *nbio;
 263         hammer2_inode_t *ip;
 264         hammer2_key_t lbase;
 265
 266         bio = ap->a_bio;
 267         bp = bio->bio_buf;
 268         ip = VTOI(ap->a_vp);
 269         nbio = push_bio(bio);
 270
 271         lbase = bio->bio_offset;
 272         KKASSERT(((int)lbase & HAMMER2_PBUFMASK) == 0);
 273
 274         if (bp->b_bio1.bio_flags & BIO_SYNC) {
 275                 xop = hammer2_xop_alloc(ip, 0);
 276         } else {
 277                 xop = hammer2_xop_alloc(ip, HAMMER2_XOP_ITERATOR);
 278         }
 279         xop->finished = 0;
 280         xop->bio = bio;
 281         xop->lbase = lbase;
 282         hammer2_mtx_init(&xop->lock, "h2bior");
 283         hammer2_xop_start(&xop->head, hammer2_strategy_xop_read);
 284         /* asynchronous completion */
 285
 286         return(0);
 287 }
 288
 289 /*
 290  * Per-node XOP (threaded), do a synchronous lookup of the chain and
 291  * its data.  The frontend is asynchronous, so we are also responsible
 292  * for racing to terminate the frontend.
 293  */
 294 static
 295 void
 296 hammer2_strategy_xop_read(hammer2_xop_t *arg, int clindex)
 297 {
 298         hammer2_xop_strategy_t *xop = &arg->xop_strategy;
 299         hammer2_chain_t *parent;
 300         hammer2_chain_t *chain;
 301         hammer2_key_t key_dummy;
 302         hammer2_key_t lbase;
 303         struct bio *bio;
 304         struct buf *bp;
 305         int cache_index = -1;
 306         int error;
 307
 308         TIMER(0);
 309         lbase = xop->lbase;
 310         bio = xop->bio;
 311         bp = bio->bio_buf;
 312
 313         parent = hammer2_inode_chain(xop->head.ip1, clindex,
 314                                      HAMMER2_RESOLVE_ALWAYS |
 315                                      HAMMER2_RESOLVE_SHARED);
 316         TIMER(1);
 317         if (parent) {
 318                 chain = hammer2_chain_lookup(&parent, &key_dummy,
 319                                              lbase, lbase,
 320                                              &cache_index,
 321                                              HAMMER2_LOOKUP_ALWAYS |
 322                                              HAMMER2_LOOKUP_SHARED);
 323                 error = chain ? chain->error : 0;
 324         } else {
 325                 error = EIO;
 326                 chain = NULL;
 327         }
 328         TIMER(2);
 329         error = hammer2_xop_feed(&xop->head, chain, clindex, error);
 330         TIMER(3);
 331         if (chain) {
 332                 hammer2_chain_unlock(chain);
 333                 hammer2_chain_drop(chain);
 334         }
 335         if (parent) {
 336                 hammer2_chain_unlock(parent);
 337                 hammer2_chain_drop(parent);
 338         }
 339         chain = NULL;   /* safety */
 340         parent = NULL;  /* safety */
 341         TIMER(4);
 342
 343         /*
 344          * Race to finish the frontend
 345          */
 346         if (xop->finished)
 347                 return;
 348         hammer2_mtx_ex(&xop->lock);
 349         if (xop->finished) {
 350                 hammer2_mtx_unlock(&xop->lock);
 351                 return;
 352         }
 353
 354         /*
 355          * Async operation has not completed and we now own the lock.
 356          * Determine if we can complete the operation by issuing the
 357          * frontend collection non-blocking.
 358          */
 359         error = hammer2_xop_collect(&xop->head, HAMMER2_XOP_COLLECT_NOWAIT);
 360         TIMER(5);
 361
 362         switch(error) {
 363         case 0:
 364                 xop->finished = 1;
 365                 hammer2_mtx_unlock(&xop->lock);
 366                 chain = xop->head.cluster.focus;
 367                 hammer2_strategy_read_completion(chain, (char *)chain->data,
 368                                                  xop->bio);
 369                 hammer2_xop_retire(&xop->head, HAMMER2_XOPMASK_VOP);
 370                 biodone(bio);
 371                 break;
 372         case ENOENT:
 373                 xop->finished = 1;
 374                 hammer2_mtx_unlock(&xop->lock);
 375                 bp->b_resid = 0;
 376                 bp->b_error = 0;
 377                 bzero(bp->b_data, bp->b_bcount);
 378                 biodone(bio);
 379                 hammer2_xop_retire(&xop->head, HAMMER2_XOPMASK_VOP);
 380                 break;
 381         case EINPROGRESS:
 382                 hammer2_mtx_unlock(&xop->lock);
 383                 break;
 384         default:
 385                 xop->finished = 1;
 386                 hammer2_mtx_unlock(&xop->lock);
 387                 bp->b_flags |= B_ERROR;
 388                 bp->b_error = EIO;
 389                 biodone(bio);
 390                 hammer2_xop_retire(&xop->head, HAMMER2_XOPMASK_VOP);
 391                 break;
 392         }
 393         TIMER(6);
 394 }
 395
 396 static
 397 void
 398 hammer2_strategy_read_completion(hammer2_chain_t *chain, char *data,
 399                                  struct bio *bio)
 400 {
 401         struct buf *bp = bio->bio_buf;
 402
 403         if (chain->bref.type == HAMMER2_BREF_TYPE_INODE) {
 404                 /*
 405                  * Data is embedded in the inode (copy from inode).
 406                  */
 407                 bcopy(((hammer2_inode_data_t *)data)->u.data,
 408                       bp->b_data, HAMMER2_EMBEDDED_BYTES);
 409                 bzero(bp->b_data + HAMMER2_EMBEDDED_BYTES,
 410                       bp->b_bcount - HAMMER2_EMBEDDED_BYTES);
 411                 bp->b_resid = 0;
 412                 bp->b_error = 0;
 413         } else if (chain->bref.type == HAMMER2_BREF_TYPE_DATA) {
 414                 /*
 415                  * Data is on-media, record for live dedup.
 416                  */
 417                 hammer2_dedup_record(chain, data);
 418
 419                 /*
 420                  * Decopmression and copy.
 421                  */
 422                 switch (HAMMER2_DEC_COMP(chain->bref.methods)) {
 423                 case HAMMER2_COMP_LZ4:
 424                         hammer2_decompress_LZ4_callback(data, chain->bytes,
 425                                                         bio);
 426                         break;
 427                 case HAMMER2_COMP_ZLIB:
 428                         hammer2_decompress_ZLIB_callback(data, chain->bytes,
 429                                                          bio);
 430                         break;
 431                 case HAMMER2_COMP_NONE:
 432                         KKASSERT(chain->bytes <= bp->b_bcount);
 433                         bcopy(data, bp->b_data, chain->bytes);
 434                         if (chain->bytes < bp->b_bcount) {
 435                                 bzero(bp->b_data + chain->bytes,
 436                                       bp->b_bcount - chain->bytes);
 437                         }
 438                         bp->b_flags |= B_NOTMETA;
 439                         bp->b_resid = 0;
 440                         bp->b_error = 0;
 441                         break;
 442                 default:
 443                         panic("hammer2_strategy_read: "
 444                               "unknown compression type");
 445                 }
 446         } else {
 447                 panic("hammer2_strategy_read: unknown bref type");
 448         }
 449 }
 450
 451 /****************************************************************************
 452  *                              WRITE SUPPORT                               *
 453  ****************************************************************************/
 454
 455 /*
 456  * Functions for compression in threads,
 457  * from hammer2_vnops.c
 458  */
 459 static void hammer2_write_file_core(struct buf *bp, hammer2_inode_t *ip,
 460                                 hammer2_chain_t **parentp,
 461                                 hammer2_key_t lbase, int ioflag, int pblksize,
 462                                 hammer2_tid_t mtid, int *errorp);
 463 static void hammer2_compress_and_write(struct buf *bp, hammer2_inode_t *ip,
 464                                 hammer2_chain_t **parentp,
 465                                 hammer2_key_t lbase, int ioflag, int pblksize,
 466                                 hammer2_tid_t mtid, int *errorp,
 467                                 int comp_algo, int check_algo);
 468 static void hammer2_zero_check_and_write(struct buf *bp, hammer2_inode_t *ip,
 469                                 hammer2_chain_t **parentp,
 470                                 hammer2_key_t lbase, int ioflag, int pblksize,
 471                                 hammer2_tid_t mtid, int *errorp,
 472                                 int check_algo);
 473 static int test_block_zeros(const char *buf, size_t bytes);
 474 static void zero_write(struct buf *bp, hammer2_inode_t *ip,
 475                                 hammer2_chain_t **parentp,
 476                                 hammer2_key_t lbase,
 477                                 hammer2_tid_t mtid, int *errorp);
 478 static void hammer2_write_bp(hammer2_chain_t *chain, struct buf *bp,
 479                                 int ioflag, int pblksize,
 480                                 hammer2_tid_t mtid, int *errorp,
 481                                 int check_algo);
 482
 483 static
 484 int
 485 hammer2_strategy_write(struct vop_strategy_args *ap)
 486 {
 487         hammer2_xop_strategy_t *xop;
 488         hammer2_pfs_t *pmp;
 489         struct bio *bio;
 490         struct buf *bp;
 491         hammer2_inode_t *ip;
 492
 493         bio = ap->a_bio;
 494         bp = bio->bio_buf;
 495         ip = VTOI(ap->a_vp);
 496         pmp = ip->pmp;
 497
 498         hammer2_lwinprog_ref(pmp);
 499         hammer2_trans_assert_strategy(pmp);
 500
 501         xop = hammer2_xop_alloc(ip, HAMMER2_XOP_MODIFYING);
 502         xop->finished = 0;
 503         xop->bio = bio;
 504         xop->lbase = bio->bio_offset;
 505         hammer2_mtx_init(&xop->lock, "h2biow");
 506         hammer2_xop_start(&xop->head, hammer2_strategy_xop_write);
 507         /* asynchronous completion */
 508
 509         hammer2_lwinprog_wait(pmp, hammer2_flush_pipe);
 510
 511         return(0);
 512 }
 513
 514 /*
 515  * Per-node XOP (threaded).  Write the logical buffer to the media.
 516  */
 517 static
 518 void
 519 hammer2_strategy_xop_write(hammer2_xop_t *arg, int clindex)
 520 {
 521         hammer2_xop_strategy_t *xop = &arg->xop_strategy;
 522         hammer2_chain_t *parent;
 523         hammer2_key_t lbase;
 524         hammer2_inode_t *ip;
 525         struct bio *bio;
 526         struct buf *bp;
 527         int error;
 528         int lblksize;
 529         int pblksize;
 530
 531         lbase = xop->lbase;
 532         bio = xop->bio;
 533         bp = bio->bio_buf;
 534         ip = xop->head.ip1;
 535
 536         /* hammer2_trans_init(parent->hmp->spmp, HAMMER2_TRANS_BUFCACHE); */
 537
 538         lblksize = hammer2_calc_logical(ip, bio->bio_offset, &lbase, NULL);
 539         pblksize = hammer2_calc_physical(ip, lbase);
 540         parent = hammer2_inode_chain(ip, clindex, HAMMER2_RESOLVE_ALWAYS);
 541         hammer2_write_file_core(bp, ip, &parent,
 542                                 lbase, IO_ASYNC, pblksize,
 543                                 xop->head.mtid, &error);
 544         if (parent) {
 545                 hammer2_chain_unlock(parent);
 546                 hammer2_chain_drop(parent);
 547                 parent = NULL;  /* safety */
 548         }
 549         error = hammer2_xop_feed(&xop->head, NULL, clindex, error);
 550
 551         /*
 552          * Race to finish the frontend
 553          */
 554         if (xop->finished)
 555                 return;
 556         hammer2_mtx_ex(&xop->lock);
 557         if (xop->finished) {
 558                 hammer2_mtx_unlock(&xop->lock);
 559                 return;
 560         }
 561
 562         /*
 563          * Async operation has not completed and we now own the lock.
 564          * Determine if we can complete the operation by issuing the
 565          * frontend collection non-blocking.
 566          */
 567         error = hammer2_xop_collect(&xop->head, HAMMER2_XOP_COLLECT_NOWAIT);
 568
 569         switch(error) {
 570         case ENOENT:
 571         case 0:
 572                 xop->finished = 1;
 573                 hammer2_mtx_unlock(&xop->lock);
 574                 bp->b_resid = 0;
 575                 bp->b_error = 0;
 576                 biodone(bio);
 577                 hammer2_xop_retire(&xop->head, HAMMER2_XOPMASK_VOP);
 578                 hammer2_lwinprog_drop(ip->pmp);
 579                 break;
 580         case EINPROGRESS:
 581                 hammer2_mtx_unlock(&xop->lock);
 582                 break;
 583         default:
 584                 xop->finished = 1;
 585                 hammer2_mtx_unlock(&xop->lock);
 586                 bp->b_flags |= B_ERROR;
 587                 bp->b_error = EIO;
 588                 biodone(bio);
 589                 hammer2_xop_retire(&xop->head, HAMMER2_XOPMASK_VOP);
 590                 hammer2_lwinprog_drop(ip->pmp);
 591                 break;
 592         }
 593 }
 594
 595 /*
 596  * Wait for pending I/O to complete
 597  */
 598 void
 599 hammer2_bioq_sync(hammer2_pfs_t *pmp)
 600 {
 601         hammer2_lwinprog_wait(pmp, 0);
 602 }
 603
 604 /*
 605  * Create a new cluster at (cparent, lbase) and assign physical storage,
 606  * returning a cluster suitable for I/O.  The cluster will be in a modified
 607  * state.
 608  *
 609  * cparent can wind up being anything.
 610  *
 611  * If datap is not NULL, *datap points to the real data we intend to write.
 612  * If we can dedup the storage location we set *datap to NULL to indicate
 613  * to the caller that a dedup occurred.
 614  *
 615  * NOTE: Special case for data embedded in inode.
 616  */
 617 static
 618 hammer2_chain_t *
 619 hammer2_assign_physical(hammer2_inode_t *ip, hammer2_chain_t **parentp,
 620                         hammer2_key_t lbase, int pblksize,
 621                         hammer2_tid_t mtid, char **datap, int *errorp)
 622 {
 623         hammer2_chain_t *chain;
 624         hammer2_key_t key_dummy;
 625         hammer2_off_t dedup_off;
 626         int pradix = hammer2_getradix(pblksize);
 627         int cache_index = -1;
 628
 629         /*
 630          * Locate the chain associated with lbase, return a locked chain.
 631          * However, do not instantiate any data reference (which utilizes a
 632          * device buffer) because we will be using direct IO via the
 633          * logical buffer cache buffer.
 634          */
 635         *errorp = 0;
 636         KKASSERT(pblksize >= HAMMER2_ALLOC_MIN);
 637 retry:
 638         TIMER(30);
 639         chain = hammer2_chain_lookup(parentp, &key_dummy,
 640                                      lbase, lbase,
 641                                      &cache_index,
 642                                      HAMMER2_LOOKUP_NODATA);
 643         if (chain == NULL) {
 644                 /*
 645                  * We found a hole, create a new chain entry.
 646                  *
 647                  * NOTE: DATA chains are created without device backing
 648                  *       store (nor do we want any).
 649                  */
 650                 dedup_off = hammer2_dedup_lookup((*parentp)->hmp, datap,
 651                                                  pblksize);
 652                 *errorp = hammer2_chain_create(parentp, &chain, ip->pmp,
 653                                                lbase, HAMMER2_PBUFRADIX,
 654                                                HAMMER2_BREF_TYPE_DATA,
 655                                                pblksize, mtid,
 656                                                dedup_off, 0);
 657                 if (chain == NULL) {
 658                         panic("hammer2_chain_create: par=%p error=%d\n",
 659                               *parentp, *errorp);
 660                         goto retry;
 661                 }
 662                 /*ip->delta_dcount += pblksize;*/
 663         } else {
 664                 switch (chain->bref.type) {
 665                 case HAMMER2_BREF_TYPE_INODE:
 666                         /*
 667                          * The data is embedded in the inode, which requires
 668                          * a bit more finess.
 669                          */
 670                         hammer2_chain_modify_ip(ip, chain, mtid, 0);
 671                         break;
 672                 case HAMMER2_BREF_TYPE_DATA:
 673                         dedup_off = hammer2_dedup_lookup(chain->hmp, datap,
 674                                                          pblksize);
 675                         if (chain->bytes != pblksize) {
 676                                 hammer2_chain_resize(ip, *parentp, chain,
 677                                                      mtid, dedup_off,
 678                                                      pradix,
 679                                                      HAMMER2_MODIFY_OPTDATA);
 680                         }
 681
 682                         /*
 683                          * DATA buffers must be marked modified whether the
 684                          * data is in a logical buffer or not.  We also have
 685                          * to make this call to fixup the chain data pointers
 686                          * after resizing in case this is an encrypted or
 687                          * compressed buffer.
 688                          */
 689                         hammer2_chain_modify(chain, mtid, dedup_off,
 690                                              HAMMER2_MODIFY_OPTDATA);
 691                         break;
 692                 default:
 693                         panic("hammer2_assign_physical: bad type");
 694                         /* NOT REACHED */
 695                         break;
 696                 }
 697         }
 698         TIMER(31);
 699         return (chain);
 700 }
 701
 702 /*
 703  * hammer2_write_file_core() - hammer2_write_thread() helper
 704  *
 705  * The core write function which determines which path to take
 706  * depending on compression settings.  We also have to locate the
 707  * related chains so we can calculate and set the check data for
 708  * the blockref.
 709  */
 710 static
 711 void
 712 hammer2_write_file_core(struct buf *bp, hammer2_inode_t *ip,
 713                         hammer2_chain_t **parentp,
 714                         hammer2_key_t lbase, int ioflag, int pblksize,
 715                         hammer2_tid_t mtid, int *errorp)
 716 {
 717         hammer2_chain_t *chain;
 718         char *data = bp->b_data;
 719
 720         switch(HAMMER2_DEC_ALGO(ip->meta.comp_algo)) {
 721         case HAMMER2_COMP_NONE:
 722                 /*
 723                  * We have to assign physical storage to the buffer
 724                  * we intend to dirty or write now to avoid deadlocks
 725                  * in the strategy code later.
 726                  *
 727                  * This can return NOOFFSET for inode-embedded data.
 728                  * The strategy code will take care of it in that case.
 729                  */
 730                 chain = hammer2_assign_physical(ip, parentp, lbase, pblksize,
 731                                                 mtid, &data, errorp);
 732                 if (chain->bref.type == HAMMER2_BREF_TYPE_INODE) {
 733                         hammer2_inode_data_t *wipdata;
 734
 735                         wipdata = &chain->data->ipdata;
 736                         KKASSERT(wipdata->meta.op_flags &
 737                                  HAMMER2_OPFLAG_DIRECTDATA);
 738                         KKASSERT(bp->b_loffset == 0);
 739                         bcopy(bp->b_data, wipdata->u.data,
 740                               HAMMER2_EMBEDDED_BYTES);
 741                         ++hammer2_iod_file_wembed;
 742                 } else if (data == NULL) {
 743                         /*
 744                          * Copy of data already present on-media.
 745                          */
 746                         chain->bref.methods =
 747                                 HAMMER2_ENC_COMP(HAMMER2_COMP_NONE) +
 748                                 HAMMER2_ENC_CHECK(ip->meta.check_algo);
 749                         hammer2_chain_setcheck(chain, bp->b_data);
 750                 } else {
 751                         hammer2_write_bp(chain, bp, ioflag, pblksize,
 752                                          mtid, errorp, ip->meta.check_algo);
 753                 }
 754                 if (chain) {
 755                         hammer2_chain_unlock(chain);
 756                         hammer2_chain_drop(chain);
 757                 }
 758                 break;
 759         case HAMMER2_COMP_AUTOZERO:
 760                 /*
 761                  * Check for zero-fill only
 762                  */
 763                 hammer2_zero_check_and_write(bp, ip, parentp,
 764                                              lbase, ioflag, pblksize,
 765                                              mtid, errorp,
 766                                              ip->meta.check_algo);
 767                 break;
 768         case HAMMER2_COMP_LZ4:
 769         case HAMMER2_COMP_ZLIB:
 770         default:
 771                 /*
 772                  * Check for zero-fill and attempt compression.
 773                  */
 774                 hammer2_compress_and_write(bp, ip, parentp,
 775                                            lbase, ioflag, pblksize,
 776                                            mtid, errorp,
 777                                            ip->meta.comp_algo,
 778                                            ip->meta.check_algo);
 779                 break;
 780         }
 781 }
 782
 783 /*
 784  * Helper
 785  *
 786  * Generic function that will perform the compression in compression
 787  * write path. The compression algorithm is determined by the settings
 788  * obtained from inode.
 789  */
 790 static
 791 void
 792 hammer2_compress_and_write(struct buf *bp, hammer2_inode_t *ip,
 793         hammer2_chain_t **parentp,
 794         hammer2_key_t lbase, int ioflag, int pblksize,
 795         hammer2_tid_t mtid, int *errorp, int comp_algo, int check_algo)
 796 {
 797         hammer2_chain_t *chain;
 798         int comp_size;
 799         int comp_block_size;
 800         char *comp_buffer;
 801         char *data;
 802
 803         if (test_block_zeros(bp->b_data, pblksize)) {
 804                 zero_write(bp, ip, parentp, lbase, mtid, errorp);
 805                 return;
 806         }
 807
 808         comp_size = 0;
 809         comp_buffer = NULL;
 810
 811         KKASSERT(pblksize / 2 <= 32768);
 812
 813         if (ip->comp_heuristic < 8 || (ip->comp_heuristic & 7) == 0) {
 814                 z_stream strm_compress;
 815                 int comp_level;
 816                 int ret;
 817
 818                 switch(HAMMER2_DEC_ALGO(comp_algo)) {
 819                 case HAMMER2_COMP_LZ4:
 820                         comp_buffer = objcache_get(cache_buffer_write,
 821                                                    M_INTWAIT);
 822                         comp_size = LZ4_compress_limitedOutput(
 823                                         bp->b_data,
 824                                         &comp_buffer[sizeof(int)],
 825                                         pblksize,
 826                                         pblksize / 2 - sizeof(int));
 827                         /*
 828                          * We need to prefix with the size, LZ4
 829                          * doesn't do it for us.  Add the related
 830                          * overhead.
 831                          */
 832                         *(int *)comp_buffer = comp_size;
 833                         if (comp_size)
 834                                 comp_size += sizeof(int);
 835                         break;
 836                 case HAMMER2_COMP_ZLIB:
 837                         comp_level = HAMMER2_DEC_LEVEL(comp_algo);
 838                         if (comp_level == 0)
 839                                 comp_level = 6; /* default zlib compression */
 840                         else if (comp_level < 6)
 841                                 comp_level = 6;
 842                         else if (comp_level > 9)
 843                                 comp_level = 9;
 844                         ret = deflateInit(&strm_compress, comp_level);
 845                         if (ret != Z_OK) {
 846                                 kprintf("HAMMER2 ZLIB: fatal error "
 847                                         "on deflateInit.\n");
 848                         }
 849
 850                         comp_buffer = objcache_get(cache_buffer_write,
 851                                                    M_INTWAIT);
 852                         strm_compress.next_in = bp->b_data;
 853                         strm_compress.avail_in = pblksize;
 854                         strm_compress.next_out = comp_buffer;
 855                         strm_compress.avail_out = pblksize / 2;
 856                         ret = deflate(&strm_compress, Z_FINISH);
 857                         if (ret == Z_STREAM_END) {
 858                                 comp_size = pblksize / 2 -
 859                                             strm_compress.avail_out;
 860                         } else {
 861                                 comp_size = 0;
 862                         }
 863                         ret = deflateEnd(&strm_compress);
 864                         break;
 865                 default:
 866                         kprintf("Error: Unknown compression method.\n");
 867                         kprintf("Comp_method = %d.\n", comp_algo);
 868                         break;
 869                 }
 870         }
 871
 872         if (comp_size == 0) {
 873                 /*
 874                  * compression failed or turned off
 875                  */
 876                 comp_block_size = pblksize;     /* safety */
 877                 if (++ip->comp_heuristic > 128)
 878                         ip->comp_heuristic = 8;
 879         } else {
 880                 /*
 881                  * compression succeeded
 882                  */
 883                 ip->comp_heuristic = 0;
 884                 if (comp_size <= 1024) {
 885                         comp_block_size = 1024;
 886                 } else if (comp_size <= 2048) {
 887                         comp_block_size = 2048;
 888                 } else if (comp_size <= 4096) {
 889                         comp_block_size = 4096;
 890                 } else if (comp_size <= 8192) {
 891                         comp_block_size = 8192;
 892                 } else if (comp_size <= 16384) {
 893                         comp_block_size = 16384;
 894                 } else if (comp_size <= 32768) {
 895                         comp_block_size = 32768;
 896                 } else {
 897                         panic("hammer2: WRITE PATH: "
 898                               "Weird comp_size value.");
 899                         /* NOT REACHED */
 900                         comp_block_size = pblksize;
 901                 }
 902
 903                 /*
 904                  * Must zero the remainder or dedup (which operates on a
 905                  * physical block basis) will not find matches.
 906                  */
 907                 if (comp_size < comp_block_size) {
 908                         bzero(comp_buffer + comp_size,
 909                               comp_block_size - comp_size);
 910                 }
 911         }
 912
 913         /*
 914          * Assign physical storage, data will be set to NULL if a live-dedup
 915          * was successful.
 916          */
 917         data = comp_size ? comp_buffer : bp->b_data;
 918         chain = hammer2_assign_physical(ip, parentp, lbase, comp_block_size,
 919                                         mtid, &data, errorp);
 920
 921         if (*errorp) {
 922                 kprintf("WRITE PATH: An error occurred while "
 923                         "assigning physical space.\n");
 924                 KKASSERT(chain == NULL);
 925                 goto done;
 926         }
 927
 928         if (chain->bref.type == HAMMER2_BREF_TYPE_INODE) {
 929                 hammer2_inode_data_t *wipdata;
 930
 931                 hammer2_chain_modify_ip(ip, chain, mtid, 0);
 932                 wipdata = &chain->data->ipdata;
 933                 KKASSERT(wipdata->meta.op_flags & HAMMER2_OPFLAG_DIRECTDATA);
 934                 KKASSERT(bp->b_loffset == 0);
 935                 bcopy(bp->b_data, wipdata->u.data, HAMMER2_EMBEDDED_BYTES);
 936                 ++hammer2_iod_file_wembed;
 937         } else if (data == NULL) {
 938                 /*
 939                  * Live deduplication, a copy of the data is already present
 940                  * on the media.
 941                  */
 942                 char *bdata;
 943
 944                 if (comp_size) {
 945                         chain->bref.methods =
 946                                 HAMMER2_ENC_COMP(comp_algo) +
 947                                 HAMMER2_ENC_CHECK(check_algo);
 948                 } else {
 949                         chain->bref.methods =
 950                                 HAMMER2_ENC_COMP(
 951                                         HAMMER2_COMP_NONE) +
 952                                 HAMMER2_ENC_CHECK(check_algo);
 953                 }
 954                 bdata = comp_size ? comp_buffer : bp->b_data;
 955                 hammer2_chain_setcheck(chain, bdata);
 956                 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_INITIAL);
 957         } else {
 958                 hammer2_io_t *dio;
 959                 char *bdata;
 960
 961                 KKASSERT(chain->flags & HAMMER2_CHAIN_MODIFIED);
 962
 963                 switch(chain->bref.type) {
 964                 case HAMMER2_BREF_TYPE_INODE:
 965                         panic("hammer2_write_bp: unexpected inode\n");
 966                         break;
 967                 case HAMMER2_BREF_TYPE_DATA:
 968                         /*
 969                          * Optimize out the read-before-write
 970                          * if possible.
 971                          */
 972                         *errorp = hammer2_io_newnz(chain->hmp,
 973                                                    chain->bref.data_off,
 974                                                    chain->bytes,
 975                                                    &dio);
 976                         if (*errorp) {
 977                                 hammer2_io_brelse(&dio);
 978                                 kprintf("hammer2: WRITE PATH: "
 979                                         "dbp bread error\n");
 980                                 break;
 981                         }
 982                         bdata = hammer2_io_data(dio, chain->bref.data_off);
 983
 984                         /*
 985                          * When loading the block make sure we don't
 986                          * leave garbage after the compressed data.
 987                          */
 988                         if (comp_size) {
 989                                 chain->bref.methods =
 990                                         HAMMER2_ENC_COMP(comp_algo) +
 991                                         HAMMER2_ENC_CHECK(check_algo);
 992                                 bcopy(comp_buffer, bdata, comp_size);
 993                         } else {
 994                                 chain->bref.methods =
 995                                         HAMMER2_ENC_COMP(
 996                                                 HAMMER2_COMP_NONE) +
 997                                         HAMMER2_ENC_CHECK(check_algo);
 998                                 bcopy(bp->b_data, bdata, pblksize);
 999                         }
1000
1001                         /*
1002                          * The flush code doesn't calculate check codes for
1003                          * file data (doing so can result in excessive I/O),
1004                          * so we do it here.
1005                          *
1006                          * Record for dedup only after the DIO's buffer cache
1007                          * buffer has been updated.
1008                          */
1009                         hammer2_chain_setcheck(chain, bdata);
1010                         hammer2_dedup_record(chain, bdata);
1011
1012                         /*
1013                          * Device buffer is now valid, chain is no longer in
1014                          * the initial state.
1015                          *
1016                          * (No blockref table worries with file data)
1017                          */
1018                         atomic_clear_int(&chain->flags, HAMMER2_CHAIN_INITIAL);
1019
1020                         /* Now write the related bdp. */
1021                         if (ioflag & IO_SYNC) {
1022                                 /*
1023                                  * Synchronous I/O requested.
1024                                  */
1025                                 hammer2_io_bwrite(&dio);
1026                         /*
1027                         } else if ((ioflag & IO_DIRECT) &&
1028                                    loff + n == pblksize) {
1029                                 hammer2_io_bdwrite(&dio);
1030                         */
1031                         } else if (ioflag & IO_ASYNC) {
1032                                 hammer2_io_bawrite(&dio);
1033                         } else {
1034                                 hammer2_io_bdwrite(&dio);
1035                         }
1036                         break;
1037                 default:
1038                         panic("hammer2_write_bp: bad chain type %d\n",
1039                                 chain->bref.type);
1040                         /* NOT REACHED */
1041                         break;
1042                 }
1043         }
1044 done:
1045         if (chain) {
1046                 hammer2_chain_unlock(chain);
1047                 hammer2_chain_drop(chain);
1048         }
1049         if (comp_buffer)
1050                 objcache_put(cache_buffer_write, comp_buffer);
1051 }
1052
1053 /*
1054  * Helper
1055  *
1056  * Function that performs zero-checking and writing without compression,
1057  * it corresponds to default zero-checking path.
1058  */
1059 static
1060 void
1061 hammer2_zero_check_and_write(struct buf *bp, hammer2_inode_t *ip,
1062         hammer2_chain_t **parentp,
1063         hammer2_key_t lbase, int ioflag, int pblksize,
1064         hammer2_tid_t mtid, int *errorp,
1065         int check_algo)
1066 {
1067         hammer2_chain_t *chain;
1068         char *data = bp->b_data;
1069
1070         if (test_block_zeros(bp->b_data, pblksize)) {
1071                 zero_write(bp, ip, parentp, lbase, mtid, errorp);
1072         } else {
1073                 chain = hammer2_assign_physical(ip, parentp, lbase, pblksize,
1074                                                 mtid, &data, errorp);
1075                 if (data) {
1076                         hammer2_write_bp(chain, bp, ioflag, pblksize,
1077                                          mtid, errorp, check_algo);
1078                 } /* else dedup occurred */
1079                 if (chain) {
1080                         hammer2_chain_unlock(chain);
1081                         hammer2_chain_drop(chain);
1082                 }
1083         }
1084 }
1085
1086 /*
1087  * Helper
1088  *
1089  * A function to test whether a block of data contains only zeros,
1090  * returns TRUE (non-zero) if the block is all zeros.
1091  */
1092 static
1093 int
1094 test_block_zeros(const char *buf, size_t bytes)
1095 {
1096         size_t i;
1097
1098         for (i = 0; i < bytes; i += sizeof(long)) {
1099                 if (*(const long *)(buf + i) != 0)
1100                         return (0);
1101         }
1102         return (1);
1103 }
1104
1105 /*
1106  * Helper
1107  *
1108  * Function to "write" a block that contains only zeros.
1109  */
1110 static
1111 void
1112 zero_write(struct buf *bp, hammer2_inode_t *ip,
1113            hammer2_chain_t **parentp,
1114            hammer2_key_t lbase, hammer2_tid_t mtid, int *errorp __unused)
1115 {
1116         hammer2_chain_t *chain;
1117         hammer2_key_t key_dummy;
1118         int cache_index = -1;
1119
1120         chain = hammer2_chain_lookup(parentp, &key_dummy,
1121                                      lbase, lbase,
1122                                      &cache_index,
1123                                      HAMMER2_LOOKUP_NODATA);
1124         if (chain) {
1125                 if (chain->bref.type == HAMMER2_BREF_TYPE_INODE) {
1126                         hammer2_inode_data_t *wipdata;
1127
1128                         hammer2_chain_modify_ip(ip, chain, mtid, 0);
1129                         wipdata = &chain->data->ipdata;
1130                         KKASSERT(wipdata->meta.op_flags &
1131                                  HAMMER2_OPFLAG_DIRECTDATA);
1132                         KKASSERT(bp->b_loffset == 0);
1133                         bzero(wipdata->u.data, HAMMER2_EMBEDDED_BYTES);
1134                         ++hammer2_iod_file_wembed;
1135                 } else {
1136                         hammer2_chain_delete(*parentp, chain,
1137                                              mtid, HAMMER2_DELETE_PERMANENT);
1138                         ++hammer2_iod_file_wzero;
1139                 }
1140                 hammer2_chain_unlock(chain);
1141                 hammer2_chain_drop(chain);
1142         } else {
1143                 ++hammer2_iod_file_wzero;
1144         }
1145 }
1146
1147 /*
1148  * Helper
1149  *
1150  * Function to write the data as it is, without performing any sort of
1151  * compression. This function is used in path without compression and
1152  * default zero-checking path.
1153  */
1154 static
1155 void
1156 hammer2_write_bp(hammer2_chain_t *chain, struct buf *bp, int ioflag,
1157                  int pblksize,
1158                  hammer2_tid_t mtid, int *errorp, int check_algo)
1159 {
1160         hammer2_inode_data_t *wipdata;
1161         hammer2_io_t *dio;
1162         char *bdata;
1163         int error;
1164
1165         error = 0;      /* XXX TODO below */
1166
1167         KKASSERT(chain->flags & HAMMER2_CHAIN_MODIFIED);
1168
1169         switch(chain->bref.type) {
1170         case HAMMER2_BREF_TYPE_INODE:
1171                 wipdata = &chain->data->ipdata;
1172                 KKASSERT(wipdata->meta.op_flags & HAMMER2_OPFLAG_DIRECTDATA);
1173                 KKASSERT(bp->b_loffset == 0);
1174                 bcopy(bp->b_data, wipdata->u.data, HAMMER2_EMBEDDED_BYTES);
1175                 error = 0;
1176                 ++hammer2_iod_file_wembed;
1177                 break;
1178         case HAMMER2_BREF_TYPE_DATA:
1179                 error = hammer2_io_newnz(chain->hmp,
1180                                          chain->bref.data_off,
1181                                          chain->bytes, &dio);
1182                 if (error) {
1183                         hammer2_io_bqrelse(&dio);
1184                         kprintf("hammer2: WRITE PATH: "
1185                                 "dbp bread error\n");
1186                         break;
1187                 }
1188                 bdata = hammer2_io_data(dio, chain->bref.data_off);
1189
1190                 chain->bref.methods = HAMMER2_ENC_COMP(HAMMER2_COMP_NONE) +
1191                                       HAMMER2_ENC_CHECK(check_algo);
1192                 bcopy(bp->b_data, bdata, chain->bytes);
1193
1194                 /*
1195                  * The flush code doesn't calculate check codes for
1196                  * file data (doing so can result in excessive I/O),
1197                  * so we do it here.
1198                  *
1199                  * Record for dedup only after the DIO's buffer cache
1200                  * buffer has been updated.
1201                  */
1202                 hammer2_chain_setcheck(chain, bdata);
1203                 hammer2_dedup_record(chain, bdata);
1204
1205                 /*
1206                  * Device buffer is now valid, chain is no longer in
1207                  * the initial state.
1208                  *
1209                  * (No blockref table worries with file data)
1210                  */
1211                 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_INITIAL);
1212
1213                 if (ioflag & IO_SYNC) {
1214                         /*
1215                          * Synchronous I/O requested.
1216                          */
1217                         hammer2_io_bwrite(&dio);
1218                 /*
1219                 } else if ((ioflag & IO_DIRECT) &&
1220                            loff + n == pblksize) {
1221                         hammer2_io_bdwrite(&dio);
1222                 */
1223                 } else if (ioflag & IO_ASYNC) {
1224                         hammer2_io_bawrite(&dio);
1225                 } else {
1226                         hammer2_io_bdwrite(&dio);
1227                 }
1228                 break;
1229         default:
1230                 panic("hammer2_write_bp: bad chain type %d\n",
1231                       chain->bref.type);
1232                 /* NOT REACHED */
1233                 error = 0;
1234                 break;
1235         }
1236         KKASSERT(error == 0);   /* XXX TODO */
1237         *errorp = error;
1238 }
1239
1240 /*
1241  * LIVE DEDUP HEURISTIC
1242  *
1243  * WARNING! This code is SMP safe but the heuristic allows SMP collisions.
1244  *          All fields must be loaded into locals and validated.
1245  */
1246 static
1247 void
1248 hammer2_dedup_record(hammer2_chain_t *chain, char *data)
1249 {
1250         hammer2_dev_t *hmp;
1251         hammer2_dedup_t *dedup;
1252         uint64_t crc;
1253         int best = 0;
1254         int i;
1255         int dticks;
1256
1257         hmp = chain->hmp;
1258
1259         switch(HAMMER2_DEC_CHECK(chain->bref.methods)) {
1260         case HAMMER2_CHECK_ISCSI32:
1261                 /*
1262                  * XXX use the built-in crc (the dedup lookup sequencing
1263                  * needs to be fixed so the check code is already present
1264                  * when dedup_lookup is called)
1265                  */
1266 #if 0
1267                 crc = (uint64_t)(uint32_t)chain->bref.check.iscsi32.value;
1268 #endif
1269                 crc = XXH64(data, chain->bytes, XXH_HAMMER2_SEED);
1270                 break;
1271         case HAMMER2_CHECK_XXHASH64:
1272                 crc = chain->bref.check.xxhash64.value;
1273                 break;
1274         case HAMMER2_CHECK_SHA192:
1275                 /*
1276                  * XXX use the built-in crc (the dedup lookup sequencing
1277                  * needs to be fixed so the check code is already present
1278                  * when dedup_lookup is called)
1279                  */
1280 #if 0
1281                 crc = ((uint64_t *)chain->bref.check.sha192.data)[0] ^
1282                       ((uint64_t *)chain->bref.check.sha192.data)[1] ^
1283                       ((uint64_t *)chain->bref.check.sha192.data)[2];
1284 #endif
1285                 crc = XXH64(data, chain->bytes, XXH_HAMMER2_SEED);
1286                 break;
1287         default:
1288                 /*
1289                  * Cannot dedup without a check code
1290                  */
1291                 return;
1292         }
1293         dedup = &hmp->heur_dedup[crc & (HAMMER2_DEDUP_HEUR_MASK & ~3)];
1294         for (i = 0; i < 4; ++i) {
1295                 if (dedup[i].data_crc == crc) {
1296                         best = i;
1297                         break;
1298                 }
1299                 dticks = (int)(dedup[i].ticks - dedup[best].ticks);
1300                 if (dticks < 0 || dticks > hz * 60 * 30)
1301                         best = i;
1302         }
1303         dedup += best;
1304         if (hammer2_debug & 0x40000) {
1305                 kprintf("REC %04x %016jx %016jx\n",
1306                         (int)(dedup - hmp->heur_dedup),
1307                         crc,
1308                         chain->bref.data_off);
1309         }
1310         dedup->ticks = ticks;
1311         dedup->data_off = chain->bref.data_off;
1312         dedup->data_crc = crc;
1313         atomic_set_int(&chain->flags, HAMMER2_CHAIN_DEDUP);
1314 }
1315
1316 static
1317 hammer2_off_t
1318 hammer2_dedup_lookup(hammer2_dev_t *hmp, char **datap, int pblksize)
1319 {
1320         hammer2_dedup_t *dedup;
1321         hammer2_io_t *dio;
1322         hammer2_off_t off;
1323         uint64_t crc;
1324         char *data;
1325         int i;
1326
1327         data = *datap;
1328         if (data == NULL)
1329                 return 0;
1330
1331         /*
1332          * XXX use the built-in crc (the dedup lookup sequencing
1333          * needs to be fixed so the check code is already present
1334          * when dedup_lookup is called)
1335          */
1336         crc = XXH64(data, pblksize, XXH_HAMMER2_SEED);
1337         dedup = &hmp->heur_dedup[crc & (HAMMER2_DEDUP_HEUR_MASK & ~3)];
1338
1339         if (hammer2_debug & 0x40000) {
1340                 kprintf("LOC %04x/4 %016jx\n",
1341                         (int)(dedup - hmp->heur_dedup),
1342                         crc);
1343         }
1344
1345         for (i = 0; i < 4; ++i) {
1346                 off = dedup[i].data_off;
1347                 cpu_ccfence();
1348                 if (dedup[i].data_crc != crc)
1349                         continue;
1350                 if ((1 << (int)(off & HAMMER2_OFF_MASK_RADIX)) != pblksize)
1351                         continue;
1352                 dio = hammer2_io_getquick(hmp, off, pblksize);
1353                 if (dio &&
1354                     bcmp(data, hammer2_io_data(dio, off), pblksize) == 0) {
1355                         if (hammer2_debug & 0x40000) {
1356                                 kprintf("DEDUP SUCCESS %016jx\n",
1357                                         (intmax_t)off);
1358                         }
1359                         hammer2_io_putblk(&dio);
1360                         *datap = NULL;
1361                         dedup[i].ticks = ticks; /* update use */
1362                         ++hammer2_iod_file_wdedup;
1363                         return off;             /* RETURN */
1364                 }
1365                 if (dio)
1366                         hammer2_io_putblk(&dio);
1367         }
1368         return 0;
1369 }
1370
1371 /*
1372  * Poof.  Races are ok, if someone gets in and reuses a dedup offset
1373  * before or while we are clearing it they will also recover the freemap
1374  * entry (set it to fully allocated), so a bulkfree race can only set it
1375  * to a possibly-free state.
1376  *
1377  * XXX ok, well, not really sure races are ok but going to run with it
1378  *     for the moment.
1379  */
1380 void
1381 hammer2_dedup_clear(hammer2_dev_t *hmp)
1382 {
1383         int i;
1384
1385         for (i = 0; i < HAMMER2_DEDUP_HEUR_SIZE; ++i) {
1386                 hmp->heur_dedup[i].data_off = 0;
1387                 hmp->heur_dedup[i].ticks = ticks - 1;
1388         }
1389 }