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((uint32_t)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         /*
 314          * This is difficult to optimize.  The logical buffer might be
 315          * partially dirty (contain dummy zero-fill pages), which would
 316          * mess up our crc calculation if we were to try a direct read.
 317          * So for now we always double-buffer through the underlying
 318          * storage.
 319          *
 320          * If not for the above problem we could conditionalize on
 321          * (1) 64KB buffer, (2) one chain (not multi-master) and
 322          * (3) !hammer2_double_buffer, and issue a direct read into the
 323          * logical buffer.
 324          */
 325         parent = hammer2_inode_chain(xop->head.ip1, clindex,
 326                                      HAMMER2_RESOLVE_ALWAYS |
 327                                      HAMMER2_RESOLVE_SHARED);
 328         TIMER(1);
 329         if (parent) {
 330                 chain = hammer2_chain_lookup(&parent, &key_dummy,
 331                                              lbase, lbase,
 332                                              &cache_index,
 333                                              HAMMER2_LOOKUP_ALWAYS |
 334                                              HAMMER2_LOOKUP_SHARED);
 335                 error = chain ? chain->error : 0;
 336         } else {
 337                 error = EIO;
 338                 chain = NULL;
 339         }
 340         TIMER(2);
 341         error = hammer2_xop_feed(&xop->head, chain, clindex, error);
 342         TIMER(3);
 343         if (chain) {
 344                 hammer2_chain_unlock(chain);
 345                 hammer2_chain_drop(chain);
 346         }
 347         if (parent) {
 348                 hammer2_chain_unlock(parent);
 349                 hammer2_chain_drop(parent);
 350         }
 351         chain = NULL;   /* safety */
 352         parent = NULL;  /* safety */
 353         TIMER(4);
 354
 355         /*
 356          * Race to finish the frontend
 357          */
 358         if (xop->finished)
 359                 return;
 360         hammer2_mtx_ex(&xop->lock);
 361         if (xop->finished) {
 362                 hammer2_mtx_unlock(&xop->lock);
 363                 return;
 364         }
 365
 366         /*
 367          * Async operation has not completed and we now own the lock.
 368          * Determine if we can complete the operation by issuing the
 369          * frontend collection non-blocking.
 370          */
 371         error = hammer2_xop_collect(&xop->head, HAMMER2_XOP_COLLECT_NOWAIT);
 372         TIMER(5);
 373
 374         switch(error) {
 375         case 0:
 376                 xop->finished = 1;
 377                 hammer2_mtx_unlock(&xop->lock);
 378                 chain = xop->head.cluster.focus;
 379                 hammer2_strategy_read_completion(chain, (char *)chain->data,
 380                                                  xop->bio);
 381                 biodone(bio);
 382                 hammer2_xop_retire(&xop->head, HAMMER2_XOPMASK_VOP);
 383                 break;
 384         case ENOENT:
 385                 xop->finished = 1;
 386                 hammer2_mtx_unlock(&xop->lock);
 387                 bp->b_resid = 0;
 388                 bp->b_error = 0;
 389                 bzero(bp->b_data, bp->b_bcount);
 390                 biodone(bio);
 391                 hammer2_xop_retire(&xop->head, HAMMER2_XOPMASK_VOP);
 392                 break;
 393         case EINPROGRESS:
 394                 hammer2_mtx_unlock(&xop->lock);
 395                 break;
 396         default:
 397                 kprintf("strategy_xop_read: error %d loff=%016jx\n",
 398                         error, bp->b_loffset);
 399                 xop->finished = 1;
 400                 hammer2_mtx_unlock(&xop->lock);
 401                 bp->b_flags |= B_ERROR;
 402                 bp->b_error = EIO;
 403                 biodone(bio);
 404                 hammer2_xop_retire(&xop->head, HAMMER2_XOPMASK_VOP);
 405                 break;
 406         }
 407         TIMER(6);
 408 }
 409
 410 static
 411 void
 412 hammer2_strategy_read_completion(hammer2_chain_t *chain, char *data,
 413                                  struct bio *bio)
 414 {
 415         struct buf *bp = bio->bio_buf;
 416
 417         if (chain->bref.type == HAMMER2_BREF_TYPE_INODE) {
 418                 /*
 419                  * Data is embedded in the inode (copy from inode).
 420                  */
 421                 bcopy(((hammer2_inode_data_t *)data)->u.data,
 422                       bp->b_data, HAMMER2_EMBEDDED_BYTES);
 423                 bzero(bp->b_data + HAMMER2_EMBEDDED_BYTES,
 424                       bp->b_bcount - HAMMER2_EMBEDDED_BYTES);
 425                 bp->b_resid = 0;
 426                 bp->b_error = 0;
 427         } else if (chain->bref.type == HAMMER2_BREF_TYPE_DATA) {
 428                 /*
 429                  * Data is on-media, record for live dedup.
 430                  */
 431                 hammer2_dedup_record(chain, data);
 432
 433                 /*
 434                  * Decompression and copy.
 435                  */
 436                 switch (HAMMER2_DEC_COMP(chain->bref.methods)) {
 437                 case HAMMER2_COMP_LZ4:
 438                         hammer2_decompress_LZ4_callback(data, chain->bytes,
 439                                                         bio);
 440                         /* b_resid set by call */
 441                         break;
 442                 case HAMMER2_COMP_ZLIB:
 443                         hammer2_decompress_ZLIB_callback(data, chain->bytes,
 444                                                          bio);
 445                         /* b_resid set by call */
 446                         break;
 447                 case HAMMER2_COMP_NONE:
 448                         KKASSERT(chain->bytes <= bp->b_bcount);
 449                         bcopy(data, bp->b_data, chain->bytes);
 450                         if (chain->bytes < bp->b_bcount) {
 451                                 bzero(bp->b_data + chain->bytes,
 452                                       bp->b_bcount - chain->bytes);
 453                         }
 454                         bp->b_flags |= B_NOTMETA;
 455                         bp->b_resid = 0;
 456                         bp->b_error = 0;
 457                         break;
 458                 default:
 459                         panic("hammer2_strategy_read: "
 460                               "unknown compression type");
 461                 }
 462         } else {
 463                 panic("hammer2_strategy_read: unknown bref type");
 464         }
 465 }
 466
 467 /****************************************************************************
 468  *                              WRITE SUPPORT                               *
 469  ****************************************************************************/
 470
 471 /*
 472  * Functions for compression in threads,
 473  * from hammer2_vnops.c
 474  */
 475 static void hammer2_write_file_core(struct buf *bp, hammer2_inode_t *ip,
 476                                 hammer2_chain_t **parentp,
 477                                 hammer2_key_t lbase, int ioflag, int pblksize,
 478                                 hammer2_tid_t mtid, int *errorp);
 479 static void hammer2_compress_and_write(struct buf *bp, hammer2_inode_t *ip,
 480                                 hammer2_chain_t **parentp,
 481                                 hammer2_key_t lbase, int ioflag, int pblksize,
 482                                 hammer2_tid_t mtid, int *errorp,
 483                                 int comp_algo, int check_algo);
 484 static void hammer2_zero_check_and_write(struct buf *bp, hammer2_inode_t *ip,
 485                                 hammer2_chain_t **parentp,
 486                                 hammer2_key_t lbase, int ioflag, int pblksize,
 487                                 hammer2_tid_t mtid, int *errorp,
 488                                 int check_algo);
 489 static int test_block_zeros(const char *buf, size_t bytes);
 490 static void zero_write(struct buf *bp, hammer2_inode_t *ip,
 491                                 hammer2_chain_t **parentp,
 492                                 hammer2_key_t lbase,
 493                                 hammer2_tid_t mtid, int *errorp);
 494 static void hammer2_write_bp(hammer2_chain_t *chain, struct buf *bp,
 495                                 int ioflag, int pblksize,
 496                                 hammer2_tid_t mtid, int *errorp,
 497                                 int check_algo);
 498
 499 static
 500 int
 501 hammer2_strategy_write(struct vop_strategy_args *ap)
 502 {
 503         hammer2_xop_strategy_t *xop;
 504         hammer2_pfs_t *pmp;
 505         struct bio *bio;
 506         struct buf *bp;
 507         hammer2_inode_t *ip;
 508
 509         bio = ap->a_bio;
 510         bp = bio->bio_buf;
 511         ip = VTOI(ap->a_vp);
 512         pmp = ip->pmp;
 513
 514         hammer2_lwinprog_ref(pmp);
 515         hammer2_trans_assert_strategy(pmp);
 516
 517         xop = hammer2_xop_alloc(ip, HAMMER2_XOP_MODIFYING);
 518         xop->finished = 0;
 519         xop->bio = bio;
 520         xop->lbase = bio->bio_offset;
 521         hammer2_mtx_init(&xop->lock, "h2biow");
 522         hammer2_xop_start(&xop->head, hammer2_strategy_xop_write);
 523         /* asynchronous completion */
 524
 525         hammer2_lwinprog_wait(pmp, hammer2_flush_pipe);
 526
 527         return(0);
 528 }
 529
 530 /*
 531  * Per-node XOP (threaded).  Write the logical buffer to the media.
 532  */
 533 static
 534 void
 535 hammer2_strategy_xop_write(hammer2_xop_t *arg, int clindex)
 536 {
 537         hammer2_xop_strategy_t *xop = &arg->xop_strategy;
 538         hammer2_chain_t *parent;
 539         hammer2_key_t lbase;
 540         hammer2_inode_t *ip;
 541         struct bio *bio;
 542         struct buf *bp;
 543         int error;
 544         int lblksize;
 545         int pblksize;
 546
 547         lbase = xop->lbase;
 548         bio = xop->bio;
 549         bp = bio->bio_buf;
 550         ip = xop->head.ip1;
 551
 552         /* hammer2_trans_init(parent->hmp->spmp, HAMMER2_TRANS_BUFCACHE); */
 553
 554         lblksize = hammer2_calc_logical(ip, bio->bio_offset, &lbase, NULL);
 555         pblksize = hammer2_calc_physical(ip, lbase);
 556         parent = hammer2_inode_chain(ip, clindex, HAMMER2_RESOLVE_ALWAYS);
 557         hammer2_write_file_core(bp, ip, &parent,
 558                                 lbase, IO_ASYNC, pblksize,
 559                                 xop->head.mtid, &error);
 560         if (parent) {
 561                 hammer2_chain_unlock(parent);
 562                 hammer2_chain_drop(parent);
 563                 parent = NULL;  /* safety */
 564         }
 565         hammer2_xop_feed(&xop->head, NULL, clindex, error);
 566
 567         /*
 568          * Race to finish the frontend
 569          */
 570         if (xop->finished)
 571                 return;
 572         hammer2_mtx_ex(&xop->lock);
 573         if (xop->finished) {
 574                 hammer2_mtx_unlock(&xop->lock);
 575                 return;
 576         }
 577
 578         /*
 579          * Async operation has not completed and we now own the lock.
 580          * Determine if we can complete the operation by issuing the
 581          * frontend collection non-blocking.
 582          */
 583         error = hammer2_xop_collect(&xop->head, HAMMER2_XOP_COLLECT_NOWAIT);
 584
 585         switch(error) {
 586         case ENOENT:
 587         case 0:
 588                 xop->finished = 1;
 589                 hammer2_mtx_unlock(&xop->lock);
 590                 bp->b_resid = 0;
 591                 bp->b_error = 0;
 592                 biodone(bio);
 593                 hammer2_xop_retire(&xop->head, HAMMER2_XOPMASK_VOP);
 594                 hammer2_lwinprog_drop(ip->pmp);
 595                 break;
 596         case EINPROGRESS:
 597                 hammer2_mtx_unlock(&xop->lock);
 598                 break;
 599         default:
 600                 kprintf("strategy_xop_write: error %d loff=%016jx\n",
 601                         error, bp->b_loffset);
 602                 xop->finished = 1;
 603                 hammer2_mtx_unlock(&xop->lock);
 604                 bp->b_flags |= B_ERROR;
 605                 bp->b_error = EIO;
 606                 biodone(bio);
 607                 hammer2_xop_retire(&xop->head, HAMMER2_XOPMASK_VOP);
 608                 hammer2_lwinprog_drop(ip->pmp);
 609                 break;
 610         }
 611 }
 612
 613 /*
 614  * Wait for pending I/O to complete
 615  */
 616 void
 617 hammer2_bioq_sync(hammer2_pfs_t *pmp)
 618 {
 619         hammer2_lwinprog_wait(pmp, 0);
 620 }
 621
 622 /*
 623  * Create a new cluster at (cparent, lbase) and assign physical storage,
 624  * returning a cluster suitable for I/O.  The cluster will be in a modified
 625  * state.
 626  *
 627  * cparent can wind up being anything.
 628  *
 629  * If datap is not NULL, *datap points to the real data we intend to write.
 630  * If we can dedup the storage location we set *datap to NULL to indicate
 631  * to the caller that a dedup occurred.
 632  *
 633  * NOTE: Special case for data embedded in inode.
 634  */
 635 static
 636 hammer2_chain_t *
 637 hammer2_assign_physical(hammer2_inode_t *ip, hammer2_chain_t **parentp,
 638                         hammer2_key_t lbase, int pblksize,
 639                         hammer2_tid_t mtid, char **datap, int *errorp)
 640 {
 641         hammer2_chain_t *chain;
 642         hammer2_key_t key_dummy;
 643         hammer2_off_t dedup_off;
 644         int pradix = hammer2_getradix(pblksize);
 645         int cache_index = -1;
 646
 647         /*
 648          * Locate the chain associated with lbase, return a locked chain.
 649          * However, do not instantiate any data reference (which utilizes a
 650          * device buffer) because we will be using direct IO via the
 651          * logical buffer cache buffer.
 652          */
 653         *errorp = 0;
 654         KKASSERT(pblksize >= HAMMER2_ALLOC_MIN);
 655 retry:
 656         TIMER(30);
 657         chain = hammer2_chain_lookup(parentp, &key_dummy,
 658                                      lbase, lbase,
 659                                      &cache_index,
 660                                      HAMMER2_LOOKUP_NODATA);
 661
 662         if (chain && (chain->flags & HAMMER2_CHAIN_DELETED))
 663                 kprintf("assign physical deleted chain @ %016jx\n",
 664                         lbase);
 665
 666         if (chain == NULL) {
 667                 /*
 668                  * We found a hole, create a new chain entry.
 669                  *
 670                  * NOTE: DATA chains are created without device backing
 671                  *       store (nor do we want any).
 672                  */
 673                 dedup_off = hammer2_dedup_lookup((*parentp)->hmp, datap,
 674                                                  pblksize);
 675                 *errorp = hammer2_chain_create(parentp, &chain, ip->pmp,
 676                                                lbase, HAMMER2_PBUFRADIX,
 677                                                HAMMER2_BREF_TYPE_DATA,
 678                                                pblksize, mtid,
 679                                                dedup_off, 0);
 680                 if (chain == NULL) {
 681                         panic("hammer2_chain_create: par=%p error=%d\n",
 682                               *parentp, *errorp);
 683                         goto retry;
 684                 }
 685                 /*ip->delta_dcount += pblksize;*/
 686         } else {
 687                 switch (chain->bref.type) {
 688                 case HAMMER2_BREF_TYPE_INODE:
 689                         /*
 690                          * The data is embedded in the inode, which requires
 691                          * a bit more finess.
 692                          */
 693                         hammer2_chain_modify_ip(ip, chain, mtid, 0);
 694                         break;
 695                 case HAMMER2_BREF_TYPE_DATA:
 696                         dedup_off = hammer2_dedup_lookup(chain->hmp, datap,
 697                                                          pblksize);
 698                         if (chain->bytes != pblksize) {
 699                                 hammer2_chain_resize(ip, *parentp, chain,
 700                                                      mtid, dedup_off,
 701                                                      pradix,
 702                                                      HAMMER2_MODIFY_OPTDATA);
 703                         }
 704
 705                         /*
 706                          * DATA buffers must be marked modified whether the
 707                          * data is in a logical buffer or not.  We also have
 708                          * to make this call to fixup the chain data pointers
 709                          * after resizing in case this is an encrypted or
 710                          * compressed buffer.
 711                          */
 712                         hammer2_chain_modify(chain, mtid, dedup_off,
 713                                              HAMMER2_MODIFY_OPTDATA);
 714                         break;
 715                 default:
 716                         panic("hammer2_assign_physical: bad type");
 717                         /* NOT REACHED */
 718                         break;
 719                 }
 720         }
 721         TIMER(31);
 722         return (chain);
 723 }
 724
 725 /*
 726  * hammer2_write_file_core() - hammer2_write_thread() helper
 727  *
 728  * The core write function which determines which path to take
 729  * depending on compression settings.  We also have to locate the
 730  * related chains so we can calculate and set the check data for
 731  * the blockref.
 732  */
 733 static
 734 void
 735 hammer2_write_file_core(struct buf *bp, hammer2_inode_t *ip,
 736                         hammer2_chain_t **parentp,
 737                         hammer2_key_t lbase, int ioflag, int pblksize,
 738                         hammer2_tid_t mtid, int *errorp)
 739 {
 740         hammer2_chain_t *chain;
 741         char *data = bp->b_data;
 742
 743         *errorp = 0;
 744
 745         switch(HAMMER2_DEC_ALGO(ip->meta.comp_algo)) {
 746         case HAMMER2_COMP_NONE:
 747                 /*
 748                  * We have to assign physical storage to the buffer
 749                  * we intend to dirty or write now to avoid deadlocks
 750                  * in the strategy code later.
 751                  *
 752                  * This can return NOOFFSET for inode-embedded data.
 753                  * The strategy code will take care of it in that case.
 754                  */
 755                 chain = hammer2_assign_physical(ip, parentp, lbase, pblksize,
 756                                                 mtid, &data, errorp);
 757                 if (chain->bref.type == HAMMER2_BREF_TYPE_INODE) {
 758                         hammer2_inode_data_t *wipdata;
 759
 760                         wipdata = &chain->data->ipdata;
 761                         KKASSERT(wipdata->meta.op_flags &
 762                                  HAMMER2_OPFLAG_DIRECTDATA);
 763                         KKASSERT(bp->b_loffset == 0);
 764                         bcopy(bp->b_data, wipdata->u.data,
 765                               HAMMER2_EMBEDDED_BYTES);
 766                         ++hammer2_iod_file_wembed;
 767                 } else if (data == NULL) {
 768                         /*
 769                          * Copy of data already present on-media.
 770                          */
 771                         chain->bref.methods =
 772                                 HAMMER2_ENC_COMP(HAMMER2_COMP_NONE) +
 773                                 HAMMER2_ENC_CHECK(ip->meta.check_algo);
 774                         hammer2_chain_setcheck(chain, bp->b_data);
 775                 } else {
 776                         hammer2_write_bp(chain, bp, ioflag, pblksize,
 777                                          mtid, errorp, ip->meta.check_algo);
 778                 }
 779                 if (chain) {
 780                         hammer2_chain_unlock(chain);
 781                         hammer2_chain_drop(chain);
 782                 }
 783                 break;
 784         case HAMMER2_COMP_AUTOZERO:
 785                 /*
 786                  * Check for zero-fill only
 787                  */
 788                 hammer2_zero_check_and_write(bp, ip, parentp,
 789                                              lbase, ioflag, pblksize,
 790                                              mtid, errorp,
 791                                              ip->meta.check_algo);
 792                 break;
 793         case HAMMER2_COMP_LZ4:
 794         case HAMMER2_COMP_ZLIB:
 795         default:
 796                 /*
 797                  * Check for zero-fill and attempt compression.
 798                  */
 799                 hammer2_compress_and_write(bp, ip, parentp,
 800                                            lbase, ioflag, pblksize,
 801                                            mtid, errorp,
 802                                            ip->meta.comp_algo,
 803                                            ip->meta.check_algo);
 804                 break;
 805         }
 806 }
 807
 808 /*
 809  * Helper
 810  *
 811  * Generic function that will perform the compression in compression
 812  * write path. The compression algorithm is determined by the settings
 813  * obtained from inode.
 814  */
 815 static
 816 void
 817 hammer2_compress_and_write(struct buf *bp, hammer2_inode_t *ip,
 818         hammer2_chain_t **parentp,
 819         hammer2_key_t lbase, int ioflag, int pblksize,
 820         hammer2_tid_t mtid, int *errorp, int comp_algo, int check_algo)
 821 {
 822         hammer2_chain_t *chain;
 823         int comp_size;
 824         int comp_block_size;
 825         char *comp_buffer;
 826         char *data;
 827
 828         if (test_block_zeros(bp->b_data, pblksize)) {
 829                 zero_write(bp, ip, parentp, lbase, mtid, errorp);
 830                 return;
 831         }
 832
 833         comp_size = 0;
 834         comp_buffer = NULL;
 835
 836         KKASSERT(pblksize / 2 <= 32768);
 837
 838         if (ip->comp_heuristic < 8 || (ip->comp_heuristic & 7) == 0) {
 839                 z_stream strm_compress;
 840                 int comp_level;
 841                 int ret;
 842
 843                 switch(HAMMER2_DEC_ALGO(comp_algo)) {
 844                 case HAMMER2_COMP_LZ4:
 845                         comp_buffer = objcache_get(cache_buffer_write,
 846                                                    M_INTWAIT);
 847                         comp_size = LZ4_compress_limitedOutput(
 848                                         bp->b_data,
 849                                         &comp_buffer[sizeof(int)],
 850                                         pblksize,
 851                                         pblksize / 2 - sizeof(int));
 852                         /*
 853                          * We need to prefix with the size, LZ4
 854                          * doesn't do it for us.  Add the related
 855                          * overhead.
 856                          */
 857                         *(int *)comp_buffer = comp_size;
 858                         if (comp_size)
 859                                 comp_size += sizeof(int);
 860                         break;
 861                 case HAMMER2_COMP_ZLIB:
 862                         comp_level = HAMMER2_DEC_LEVEL(comp_algo);
 863                         if (comp_level == 0)
 864                                 comp_level = 6; /* default zlib compression */
 865                         else if (comp_level < 6)
 866                                 comp_level = 6;
 867                         else if (comp_level > 9)
 868                                 comp_level = 9;
 869                         ret = deflateInit(&strm_compress, comp_level);
 870                         if (ret != Z_OK) {
 871                                 kprintf("HAMMER2 ZLIB: fatal error "
 872                                         "on deflateInit.\n");
 873                         }
 874
 875                         comp_buffer = objcache_get(cache_buffer_write,
 876                                                    M_INTWAIT);
 877                         strm_compress.next_in = bp->b_data;
 878                         strm_compress.avail_in = pblksize;
 879                         strm_compress.next_out = comp_buffer;
 880                         strm_compress.avail_out = pblksize / 2;
 881                         ret = deflate(&strm_compress, Z_FINISH);
 882                         if (ret == Z_STREAM_END) {
 883                                 comp_size = pblksize / 2 -
 884                                             strm_compress.avail_out;
 885                         } else {
 886                                 comp_size = 0;
 887                         }
 888                         ret = deflateEnd(&strm_compress);
 889                         break;
 890                 default:
 891                         kprintf("Error: Unknown compression method.\n");
 892                         kprintf("Comp_method = %d.\n", comp_algo);
 893                         break;
 894                 }
 895         }
 896
 897         if (comp_size == 0) {
 898                 /*
 899                  * compression failed or turned off
 900                  */
 901                 comp_block_size = pblksize;     /* safety */
 902                 if (++ip->comp_heuristic > 128)
 903                         ip->comp_heuristic = 8;
 904         } else {
 905                 /*
 906                  * compression succeeded
 907                  */
 908                 ip->comp_heuristic = 0;
 909                 if (comp_size <= 1024) {
 910                         comp_block_size = 1024;
 911                 } else if (comp_size <= 2048) {
 912                         comp_block_size = 2048;
 913                 } else if (comp_size <= 4096) {
 914                         comp_block_size = 4096;
 915                 } else if (comp_size <= 8192) {
 916                         comp_block_size = 8192;
 917                 } else if (comp_size <= 16384) {
 918                         comp_block_size = 16384;
 919                 } else if (comp_size <= 32768) {
 920                         comp_block_size = 32768;
 921                 } else {
 922                         panic("hammer2: WRITE PATH: "
 923                               "Weird comp_size value.");
 924                         /* NOT REACHED */
 925                         comp_block_size = pblksize;
 926                 }
 927
 928                 /*
 929                  * Must zero the remainder or dedup (which operates on a
 930                  * physical block basis) will not find matches.
 931                  */
 932                 if (comp_size < comp_block_size) {
 933                         bzero(comp_buffer + comp_size,
 934                               comp_block_size - comp_size);
 935                 }
 936         }
 937
 938         /*
 939          * Assign physical storage, data will be set to NULL if a live-dedup
 940          * was successful.
 941          */
 942         data = comp_size ? comp_buffer : bp->b_data;
 943         chain = hammer2_assign_physical(ip, parentp, lbase, comp_block_size,
 944                                         mtid, &data, errorp);
 945
 946         if (*errorp) {
 947                 kprintf("WRITE PATH: An error occurred while "
 948                         "assigning physical space.\n");
 949                 KKASSERT(chain == NULL);
 950                 goto done;
 951         }
 952
 953         if (chain->bref.type == HAMMER2_BREF_TYPE_INODE) {
 954                 hammer2_inode_data_t *wipdata;
 955
 956                 hammer2_chain_modify_ip(ip, chain, mtid, 0);
 957                 wipdata = &chain->data->ipdata;
 958                 KKASSERT(wipdata->meta.op_flags & HAMMER2_OPFLAG_DIRECTDATA);
 959                 KKASSERT(bp->b_loffset == 0);
 960                 bcopy(bp->b_data, wipdata->u.data, HAMMER2_EMBEDDED_BYTES);
 961                 ++hammer2_iod_file_wembed;
 962         } else if (data == NULL) {
 963                 /*
 964                  * Live deduplication, a copy of the data is already present
 965                  * on the media.
 966                  */
 967                 char *bdata;
 968
 969                 if (comp_size) {
 970                         chain->bref.methods =
 971                                 HAMMER2_ENC_COMP(comp_algo) +
 972                                 HAMMER2_ENC_CHECK(check_algo);
 973                 } else {
 974                         chain->bref.methods =
 975                                 HAMMER2_ENC_COMP(
 976                                         HAMMER2_COMP_NONE) +
 977                                 HAMMER2_ENC_CHECK(check_algo);
 978                 }
 979                 bdata = comp_size ? comp_buffer : bp->b_data;
 980                 hammer2_chain_setcheck(chain, bdata);
 981                 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_INITIAL);
 982         } else {
 983                 hammer2_io_t *dio;
 984                 char *bdata;
 985
 986                 KKASSERT(chain->flags & HAMMER2_CHAIN_MODIFIED);
 987
 988                 switch(chain->bref.type) {
 989                 case HAMMER2_BREF_TYPE_INODE:
 990                         panic("hammer2_write_bp: unexpected inode\n");
 991                         break;
 992                 case HAMMER2_BREF_TYPE_DATA:
 993                         /*
 994                          * Optimize out the read-before-write
 995                          * if possible.
 996                          */
 997                         *errorp = hammer2_io_newnz(chain->hmp,
 998                                                    chain->bref.type,
 999                                                    chain->bref.data_off,
1000                                                    chain->bytes,
1001                                                    &dio);
1002                         if (*errorp) {
1003                                 hammer2_io_brelse(&dio);
1004                                 kprintf("hammer2: WRITE PATH: "
1005                                         "dbp bread error\n");
1006                                 break;
1007                         }
1008                         bdata = hammer2_io_data(dio, chain->bref.data_off);
1009
1010                         /*
1011                          * When loading the block make sure we don't
1012                          * leave garbage after the compressed data.
1013                          */
1014                         if (comp_size) {
1015                                 chain->bref.methods =
1016                                         HAMMER2_ENC_COMP(comp_algo) +
1017                                         HAMMER2_ENC_CHECK(check_algo);
1018                                 bcopy(comp_buffer, bdata, comp_size);
1019                         } else {
1020                                 chain->bref.methods =
1021                                         HAMMER2_ENC_COMP(
1022                                                 HAMMER2_COMP_NONE) +
1023                                         HAMMER2_ENC_CHECK(check_algo);
1024                                 bcopy(bp->b_data, bdata, pblksize);
1025                         }
1026
1027                         /*
1028                          * The flush code doesn't calculate check codes for
1029                          * file data (doing so can result in excessive I/O),
1030                          * so we do it here.
1031                          *
1032                          * Record for dedup only after the DIO's buffer cache
1033                          * buffer has been updated.
1034                          */
1035                         hammer2_chain_setcheck(chain, bdata);
1036                         hammer2_dedup_record(chain, bdata);
1037
1038                         /*
1039                          * Device buffer is now valid, chain is no longer in
1040                          * the initial state.
1041                          *
1042                          * (No blockref table worries with file data)
1043                          */
1044                         atomic_clear_int(&chain->flags, HAMMER2_CHAIN_INITIAL);
1045
1046                         /* Now write the related bdp. */
1047                         if (ioflag & IO_SYNC) {
1048                                 /*
1049                                  * Synchronous I/O requested.
1050                                  */
1051                                 hammer2_io_bwrite(&dio);
1052                         /*
1053                         } else if ((ioflag & IO_DIRECT) &&
1054                                    loff + n == pblksize) {
1055                                 hammer2_io_bdwrite(&dio);
1056                         */
1057                         } else if (ioflag & IO_ASYNC) {
1058                                 hammer2_io_bawrite(&dio);
1059                         } else {
1060                                 hammer2_io_bdwrite(&dio);
1061                         }
1062                         break;
1063                 default:
1064                         panic("hammer2_write_bp: bad chain type %d\n",
1065                                 chain->bref.type);
1066                         /* NOT REACHED */
1067                         break;
1068                 }
1069         }
1070 done:
1071         if (chain) {
1072                 hammer2_chain_unlock(chain);
1073                 hammer2_chain_drop(chain);
1074         }
1075         if (comp_buffer)
1076                 objcache_put(cache_buffer_write, comp_buffer);
1077 }
1078
1079 /*
1080  * Helper
1081  *
1082  * Function that performs zero-checking and writing without compression,
1083  * it corresponds to default zero-checking path.
1084  */
1085 static
1086 void
1087 hammer2_zero_check_and_write(struct buf *bp, hammer2_inode_t *ip,
1088         hammer2_chain_t **parentp,
1089         hammer2_key_t lbase, int ioflag, int pblksize,
1090         hammer2_tid_t mtid, int *errorp,
1091         int check_algo)
1092 {
1093         hammer2_chain_t *chain;
1094         char *data = bp->b_data;
1095
1096         if (test_block_zeros(bp->b_data, pblksize)) {
1097                 zero_write(bp, ip, parentp, lbase, mtid, errorp);
1098         } else {
1099                 chain = hammer2_assign_physical(ip, parentp, lbase, pblksize,
1100                                                 mtid, &data, errorp);
1101                 if (data) {
1102                         hammer2_write_bp(chain, bp, ioflag, pblksize,
1103                                          mtid, errorp, check_algo);
1104                 } /* else dedup occurred */
1105                 if (chain) {
1106                         hammer2_chain_unlock(chain);
1107                         hammer2_chain_drop(chain);
1108                 }
1109         }
1110 }
1111
1112 /*
1113  * Helper
1114  *
1115  * A function to test whether a block of data contains only zeros,
1116  * returns TRUE (non-zero) if the block is all zeros.
1117  */
1118 static
1119 int
1120 test_block_zeros(const char *buf, size_t bytes)
1121 {
1122         size_t i;
1123
1124         for (i = 0; i < bytes; i += sizeof(long)) {
1125                 if (*(const long *)(buf + i) != 0)
1126                         return (0);
1127         }
1128         return (1);
1129 }
1130
1131 /*
1132  * Helper
1133  *
1134  * Function to "write" a block that contains only zeros.
1135  */
1136 static
1137 void
1138 zero_write(struct buf *bp, hammer2_inode_t *ip,
1139            hammer2_chain_t **parentp,
1140            hammer2_key_t lbase, hammer2_tid_t mtid, int *errorp)
1141 {
1142         hammer2_chain_t *chain;
1143         hammer2_key_t key_dummy;
1144         int cache_index = -1;
1145
1146         *errorp = 0;
1147         chain = hammer2_chain_lookup(parentp, &key_dummy,
1148                                      lbase, lbase,
1149                                      &cache_index,
1150                                      HAMMER2_LOOKUP_NODATA);
1151         if (chain) {
1152                 if (chain->bref.type == HAMMER2_BREF_TYPE_INODE) {
1153                         hammer2_inode_data_t *wipdata;
1154
1155                         hammer2_chain_modify_ip(ip, chain, mtid, 0);
1156                         wipdata = &chain->data->ipdata;
1157                         KKASSERT(wipdata->meta.op_flags &
1158                                  HAMMER2_OPFLAG_DIRECTDATA);
1159                         KKASSERT(bp->b_loffset == 0);
1160                         bzero(wipdata->u.data, HAMMER2_EMBEDDED_BYTES);
1161                         ++hammer2_iod_file_wembed;
1162                 } else {
1163                         hammer2_chain_delete(*parentp, chain,
1164                                              mtid, HAMMER2_DELETE_PERMANENT);
1165                         ++hammer2_iod_file_wzero;
1166                 }
1167                 hammer2_chain_unlock(chain);
1168                 hammer2_chain_drop(chain);
1169         } else {
1170                 ++hammer2_iod_file_wzero;
1171         }
1172 }
1173
1174 /*
1175  * Helper
1176  *
1177  * Function to write the data as it is, without performing any sort of
1178  * compression. This function is used in path without compression and
1179  * default zero-checking path.
1180  */
1181 static
1182 void
1183 hammer2_write_bp(hammer2_chain_t *chain, struct buf *bp, int ioflag,
1184                  int pblksize,
1185                  hammer2_tid_t mtid, int *errorp, int check_algo)
1186 {
1187         hammer2_inode_data_t *wipdata;
1188         hammer2_io_t *dio;
1189         char *bdata;
1190         int error;
1191
1192         error = 0;      /* XXX TODO below */
1193
1194         KKASSERT(chain->flags & HAMMER2_CHAIN_MODIFIED);
1195
1196         switch(chain->bref.type) {
1197         case HAMMER2_BREF_TYPE_INODE:
1198                 wipdata = &chain->data->ipdata;
1199                 KKASSERT(wipdata->meta.op_flags & HAMMER2_OPFLAG_DIRECTDATA);
1200                 KKASSERT(bp->b_loffset == 0);
1201                 bcopy(bp->b_data, wipdata->u.data, HAMMER2_EMBEDDED_BYTES);
1202                 error = 0;
1203                 ++hammer2_iod_file_wembed;
1204                 break;
1205         case HAMMER2_BREF_TYPE_DATA:
1206                 error = hammer2_io_newnz(chain->hmp,
1207                                          chain->bref.type,
1208                                          chain->bref.data_off,
1209                                          chain->bytes, &dio);
1210                 if (error) {
1211                         hammer2_io_bqrelse(&dio);
1212                         kprintf("hammer2: WRITE PATH: "
1213                                 "dbp bread error\n");
1214                         break;
1215                 }
1216                 bdata = hammer2_io_data(dio, chain->bref.data_off);
1217
1218                 chain->bref.methods = HAMMER2_ENC_COMP(HAMMER2_COMP_NONE) +
1219                                       HAMMER2_ENC_CHECK(check_algo);
1220                 bcopy(bp->b_data, bdata, chain->bytes);
1221
1222                 /*
1223                  * The flush code doesn't calculate check codes for
1224                  * file data (doing so can result in excessive I/O),
1225                  * so we do it here.
1226                  *
1227                  * Record for dedup only after the DIO's buffer cache
1228                  * buffer has been updated.
1229                  */
1230                 hammer2_chain_setcheck(chain, bdata);
1231                 hammer2_dedup_record(chain, bdata);
1232
1233                 /*
1234                  * Device buffer is now valid, chain is no longer in
1235                  * the initial state.
1236                  *
1237                  * (No blockref table worries with file data)
1238                  */
1239                 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_INITIAL);
1240
1241                 if (ioflag & IO_SYNC) {
1242                         /*
1243                          * Synchronous I/O requested.
1244                          */
1245                         hammer2_io_bwrite(&dio);
1246                 /*
1247                 } else if ((ioflag & IO_DIRECT) &&
1248                            loff + n == pblksize) {
1249                         hammer2_io_bdwrite(&dio);
1250                 */
1251                 } else if (ioflag & IO_ASYNC) {
1252                         hammer2_io_bawrite(&dio);
1253                 } else {
1254                         hammer2_io_bdwrite(&dio);
1255                 }
1256                 break;
1257         default:
1258                 panic("hammer2_write_bp: bad chain type %d\n",
1259                       chain->bref.type);
1260                 /* NOT REACHED */
1261                 error = 0;
1262                 break;
1263         }
1264         KKASSERT(error == 0);   /* XXX TODO */
1265         *errorp = error;
1266 }
1267
1268 /*
1269  * LIVE DEDUP HEURISTIC
1270  *
1271  * WARNING! This code is SMP safe but the heuristic allows SMP collisions.
1272  *          All fields must be loaded into locals and validated.
1273  */
1274 static
1275 void
1276 hammer2_dedup_record(hammer2_chain_t *chain, char *data)
1277 {
1278         hammer2_dev_t *hmp;
1279         hammer2_dedup_t *dedup;
1280         uint64_t crc;
1281         int best = 0;
1282         int i;
1283         int dticks;
1284
1285         hmp = chain->hmp;
1286
1287         switch(HAMMER2_DEC_CHECK(chain->bref.methods)) {
1288         case HAMMER2_CHECK_ISCSI32:
1289                 /*
1290                  * XXX use the built-in crc (the dedup lookup sequencing
1291                  * needs to be fixed so the check code is already present
1292                  * when dedup_lookup is called)
1293                  */
1294 #if 0
1295                 crc = (uint64_t)(uint32_t)chain->bref.check.iscsi32.value;
1296 #endif
1297                 crc = XXH64(data, chain->bytes, XXH_HAMMER2_SEED);
1298                 break;
1299         case HAMMER2_CHECK_XXHASH64:
1300                 crc = chain->bref.check.xxhash64.value;
1301                 break;
1302         case HAMMER2_CHECK_SHA192:
1303                 /*
1304                  * XXX use the built-in crc (the dedup lookup sequencing
1305                  * needs to be fixed so the check code is already present
1306                  * when dedup_lookup is called)
1307                  */
1308 #if 0
1309                 crc = ((uint64_t *)chain->bref.check.sha192.data)[0] ^
1310                       ((uint64_t *)chain->bref.check.sha192.data)[1] ^
1311                       ((uint64_t *)chain->bref.check.sha192.data)[2];
1312 #endif
1313                 crc = XXH64(data, chain->bytes, XXH_HAMMER2_SEED);
1314                 break;
1315         default:
1316                 /*
1317                  * Cannot dedup without a check code
1318                  */
1319                 return;
1320         }
1321         dedup = &hmp->heur_dedup[crc & (HAMMER2_DEDUP_HEUR_MASK & ~3)];
1322         for (i = 0; i < 4; ++i) {
1323                 if (dedup[i].data_crc == crc) {
1324                         best = i;
1325                         break;
1326                 }
1327                 dticks = (int)(dedup[i].ticks - dedup[best].ticks);
1328                 if (dticks < 0 || dticks > hz * 60 * 30)
1329                         best = i;
1330         }
1331         dedup += best;
1332         if (hammer2_debug & 0x40000) {
1333                 kprintf("REC %04x %016jx %016jx\n",
1334                         (int)(dedup - hmp->heur_dedup),
1335                         crc,
1336                         chain->bref.data_off);
1337         }
1338         dedup->ticks = ticks;
1339         dedup->data_off = chain->bref.data_off;
1340         dedup->data_crc = crc;
1341         atomic_set_int(&chain->flags, HAMMER2_CHAIN_DEDUP);
1342 }
1343
1344 static
1345 hammer2_off_t
1346 hammer2_dedup_lookup(hammer2_dev_t *hmp, char **datap, int pblksize)
1347 {
1348         hammer2_dedup_t *dedup;
1349         hammer2_io_t *dio;
1350         hammer2_off_t off;
1351         uint64_t crc;
1352         char *data;
1353         int i;
1354
1355         data = *datap;
1356         if (data == NULL)
1357                 return 0;
1358
1359         /*
1360          * XXX use the built-in crc (the dedup lookup sequencing
1361          * needs to be fixed so the check code is already present
1362          * when dedup_lookup is called)
1363          */
1364         crc = XXH64(data, pblksize, XXH_HAMMER2_SEED);
1365         dedup = &hmp->heur_dedup[crc & (HAMMER2_DEDUP_HEUR_MASK & ~3)];
1366
1367         if (hammer2_debug & 0x40000) {
1368                 kprintf("LOC %04x/4 %016jx\n",
1369                         (int)(dedup - hmp->heur_dedup),
1370                         crc);
1371         }
1372
1373         for (i = 0; i < 4; ++i) {
1374                 off = dedup[i].data_off;
1375                 cpu_ccfence();
1376                 if (dedup[i].data_crc != crc)
1377                         continue;
1378                 if ((1 << (int)(off & HAMMER2_OFF_MASK_RADIX)) != pblksize)
1379                         continue;
1380                 dio = hammer2_io_getquick(hmp, off, pblksize);
1381                 if (dio &&
1382                     bcmp(data, hammer2_io_data(dio, off), pblksize) == 0) {
1383                         if (hammer2_debug & 0x40000) {
1384                                 kprintf("DEDUP SUCCESS %016jx\n",
1385                                         (intmax_t)off);
1386                         }
1387                         hammer2_io_putblk(&dio);
1388                         *datap = NULL;
1389                         dedup[i].ticks = ticks; /* update use */
1390                         ++hammer2_iod_file_wdedup;
1391                         return off;             /* RETURN */
1392                 }
1393                 if (dio)
1394                         hammer2_io_putblk(&dio);
1395         }
1396         return 0;
1397 }
1398
1399 /*
1400  * Poof.  Races are ok, if someone gets in and reuses a dedup offset
1401  * before or while we are clearing it they will also recover the freemap
1402  * entry (set it to fully allocated), so a bulkfree race can only set it
1403  * to a possibly-free state.
1404  *
1405  * XXX ok, well, not really sure races are ok but going to run with it
1406  *     for the moment.
1407  */
1408 void
1409 hammer2_dedup_clear(hammer2_dev_t *hmp)
1410 {
1411         int i;
1412
1413         for (i = 0; i < HAMMER2_DEDUP_HEUR_SIZE; ++i) {
1414                 hmp->heur_dedup[i].data_off = 0;
1415                 hmp->heur_dedup[i].ticks = ticks - 1;
1416         }
1417 }