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