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  * It should only be possible for this to be called outside of a flush,
  75  * or during the PREFLUSH stage of a flush.  A transaction must be used
  76  * to interlock against a new flush starting up to avoid corrupting the
  77  * flush.
  78  *
  79  * Except for the transaction init (which should normally not block),
  80  * we essentially run the strategy operation asynchronously via a XOP.
  81  *
  82  * XXX This isn't supposed to be able to deadlock against vfs_sync vfsync()
  83  *     calls but it has in the past when multiple flushes are queued.
  84  *
  85  * XXX We currently terminate the transaction once we get a quorum, otherwise
  86  *     the frontend can stall, but this can leave the remaining nodes with
  87  *     a potential flush conflict.  We need to delay flushes on those nodes
  88  *     until running transactions complete separately from the normal
  89  *     transaction sequencing.  FIXME TODO.
  90  */
  91 static void hammer2_strategy_xop_read(hammer2_xop_t *arg, int clindex);
  92 static void hammer2_strategy_xop_write(hammer2_xop_t *arg, int clindex);
  93 static int hammer2_strategy_read(struct vop_strategy_args *ap);
  94 static int hammer2_strategy_write(struct vop_strategy_args *ap);
  95 static void hammer2_strategy_read_completion(hammer2_chain_t *chain,
  96                                 char *data, struct bio *bio);
  97
  98 static hammer2_off_t hammer2_dedup_lookup(hammer2_dev_t *hmp,
  99                         char **datap, int pblksize);
 100
 101 int h2timer[32];
 102 int h2last;
 103 int h2lid;
 104
 105 #define TIMER(which)    do {                            \
 106         if (h2last)                                     \
 107                 h2timer[h2lid] += (int)(ticks - h2last);\
 108         h2last = ticks;                                 \
 109         h2lid = which;                                  \
 110 } while(0)
 111
 112 int
 113 hammer2_vop_strategy(struct vop_strategy_args *ap)
 114 {
 115         struct bio *biop;
 116         struct buf *bp;
 117         int error;
 118
 119         biop = ap->a_bio;
 120         bp = biop->bio_buf;
 121
 122         switch(bp->b_cmd) {
 123         case BUF_CMD_READ:
 124                 error = hammer2_strategy_read(ap);
 125                 ++hammer2_iod_file_read;
 126                 break;
 127         case BUF_CMD_WRITE:
 128                 error = hammer2_strategy_write(ap);
 129                 ++hammer2_iod_file_write;
 130                 break;
 131         default:
 132                 bp->b_error = error = EINVAL;
 133                 bp->b_flags |= B_ERROR;
 134                 biodone(biop);
 135                 break;
 136         }
 137         return (error);
 138 }
 139
 140 /*
 141  * Return the largest contiguous physical disk range for the logical
 142  * request, in bytes.
 143  *
 144  * (struct vnode *vp, off_t loffset, off_t *doffsetp, int *runp, int *runb)
 145  *
 146  * Basically disabled, the logical buffer write thread has to deal with
 147  * buffers one-at-a-time.  Note that this should not prevent cluster_read()
 148  * from reading-ahead, it simply prevents it from trying form a single
 149  * cluster buffer for the logical request.  H2 already uses 64KB buffers!
 150  */
 151 int
 152 hammer2_vop_bmap(struct vop_bmap_args *ap)
 153 {
 154         *ap->a_doffsetp = NOOFFSET;
 155         if (ap->a_runp)
 156                 *ap->a_runp = 0;
 157         if (ap->a_runb)
 158                 *ap->a_runb = 0;
 159         return (EOPNOTSUPP);
 160 }
 161
 162 /****************************************************************************
 163  *                              READ SUPPORT                                *
 164  ****************************************************************************/
 165 /*
 166  * Callback used in read path in case that a block is compressed with LZ4.
 167  */
 168 static
 169 void
 170 hammer2_decompress_LZ4_callback(const char *data, u_int bytes, struct bio *bio)
 171 {
 172         struct buf *bp;
 173         char *compressed_buffer;
 174         int compressed_size;
 175         int result;
 176
 177         bp = bio->bio_buf;
 178
 179 #if 0
 180         if bio->bio_caller_info2.index &&
 181               bio->bio_caller_info1.uvalue32 !=
 182               crc32(bp->b_data, bp->b_bufsize) --- return error
 183 #endif
 184
 185         KKASSERT(bp->b_bufsize <= HAMMER2_PBUFSIZE);
 186         compressed_size = *(const int *)data;
 187         KKASSERT((uint32_t)compressed_size <= bytes - sizeof(int));
 188
 189         compressed_buffer = objcache_get(cache_buffer_read, M_INTWAIT);
 190         result = LZ4_decompress_safe(__DECONST(char *, &data[sizeof(int)]),
 191                                      compressed_buffer,
 192                                      compressed_size,
 193                                      bp->b_bufsize);
 194         if (result < 0) {
 195                 kprintf("READ PATH: Error during decompression."
 196                         "bio %016jx/%d\n",
 197                         (intmax_t)bio->bio_offset, bytes);
 198                 /* make sure it isn't random garbage */
 199                 bzero(compressed_buffer, bp->b_bufsize);
 200         }
 201         KKASSERT(result <= bp->b_bufsize);
 202         bcopy(compressed_buffer, bp->b_data, bp->b_bufsize);
 203         if (result < bp->b_bufsize)
 204                 bzero(bp->b_data + result, bp->b_bufsize - result);
 205         objcache_put(cache_buffer_read, compressed_buffer);
 206         bp->b_resid = 0;
 207         bp->b_flags |= B_AGE;
 208 }
 209
 210 /*
 211  * Callback used in read path in case that a block is compressed with ZLIB.
 212  * It is almost identical to LZ4 callback, so in theory they can be unified,
 213  * but we didn't want to make changes in bio structure for that.
 214  */
 215 static
 216 void
 217 hammer2_decompress_ZLIB_callback(const char *data, u_int bytes, struct bio *bio)
 218 {
 219         struct buf *bp;
 220         char *compressed_buffer;
 221         z_stream strm_decompress;
 222         int result;
 223         int ret;
 224
 225         bp = bio->bio_buf;
 226
 227         KKASSERT(bp->b_bufsize <= HAMMER2_PBUFSIZE);
 228         strm_decompress.avail_in = 0;
 229         strm_decompress.next_in = Z_NULL;
 230
 231         ret = inflateInit(&strm_decompress);
 232
 233         if (ret != Z_OK)
 234                 kprintf("HAMMER2 ZLIB: Fatal error in inflateInit.\n");
 235
 236         compressed_buffer = objcache_get(cache_buffer_read, M_INTWAIT);
 237         strm_decompress.next_in = __DECONST(char *, data);
 238
 239         /* XXX supply proper size, subset of device bp */
 240         strm_decompress.avail_in = bytes;
 241         strm_decompress.next_out = compressed_buffer;
 242         strm_decompress.avail_out = bp->b_bufsize;
 243
 244         ret = inflate(&strm_decompress, Z_FINISH);
 245         if (ret != Z_STREAM_END) {
 246                 kprintf("HAMMER2 ZLIB: Fatar error during decompression.\n");
 247                 bzero(compressed_buffer, bp->b_bufsize);
 248         }
 249         bcopy(compressed_buffer, bp->b_data, bp->b_bufsize);
 250         result = bp->b_bufsize - strm_decompress.avail_out;
 251         if (result < bp->b_bufsize)
 252                 bzero(bp->b_data + result, strm_decompress.avail_out);
 253         objcache_put(cache_buffer_read, compressed_buffer);
 254         ret = inflateEnd(&strm_decompress);
 255
 256         bp->b_resid = 0;
 257         bp->b_flags |= B_AGE;
 258 }
 259
 260 /*
 261  * Logical buffer I/O, async read.
 262  */
 263 static
 264 int
 265 hammer2_strategy_read(struct vop_strategy_args *ap)
 266 {
 267         hammer2_xop_strategy_t *xop;
 268         struct buf *bp;
 269         struct bio *bio;
 270         struct bio *nbio;
 271         hammer2_inode_t *ip;
 272         hammer2_key_t lbase;
 273
 274         bio = ap->a_bio;
 275         bp = bio->bio_buf;
 276         ip = VTOI(ap->a_vp);
 277         nbio = push_bio(bio);
 278
 279         lbase = bio->bio_offset;
 280         KKASSERT(((int)lbase & HAMMER2_PBUFMASK) == 0);
 281
 282         if (bp->b_bio1.bio_flags & BIO_SYNC) {
 283                 xop = hammer2_xop_alloc(ip, 0);
 284         } else {
 285                 xop = hammer2_xop_alloc(ip, HAMMER2_XOP_ITERATOR);
 286         }
 287         xop->finished = 0;
 288         xop->bio = bio;
 289         xop->lbase = lbase;
 290         hammer2_mtx_init(&xop->lock, "h2bior");
 291         hammer2_xop_start(&xop->head, hammer2_strategy_xop_read);
 292         /* asynchronous completion */
 293
 294         return(0);
 295 }
 296
 297 /*
 298  * Per-node XOP (threaded), do a synchronous lookup of the chain and
 299  * its data.  The frontend is asynchronous, so we are also responsible
 300  * for racing to terminate the frontend.
 301  */
 302 static
 303 void
 304 hammer2_strategy_xop_read(hammer2_xop_t *arg, int clindex)
 305 {
 306         hammer2_xop_strategy_t *xop = &arg->xop_strategy;
 307         hammer2_chain_t *parent;
 308         hammer2_chain_t *chain;
 309         hammer2_key_t key_dummy;
 310         hammer2_key_t lbase;
 311         struct bio *bio;
 312         struct buf *bp;
 313         int cache_index = -1;
 314         int error;
 315
 316         TIMER(0);
 317         lbase = xop->lbase;
 318         bio = xop->bio;
 319         bp = bio->bio_buf;
 320
 321         /*
 322          * This is difficult to optimize.  The logical buffer might be
 323          * partially dirty (contain dummy zero-fill pages), which would
 324          * mess up our crc calculation if we were to try a direct read.
 325          * So for now we always double-buffer through the underlying
 326          * storage.
 327          *
 328          * If not for the above problem we could conditionalize on
 329          * (1) 64KB buffer, (2) one chain (not multi-master) and
 330          * (3) !hammer2_double_buffer, and issue a direct read into the
 331          * logical buffer.
 332          */
 333         parent = hammer2_inode_chain(xop->head.ip1, clindex,
 334                                      HAMMER2_RESOLVE_ALWAYS |
 335                                      HAMMER2_RESOLVE_SHARED);
 336         TIMER(1);
 337         if (parent) {
 338                 chain = hammer2_chain_lookup(&parent, &key_dummy,
 339                                              lbase, lbase,
 340                                              &cache_index,
 341                                              HAMMER2_LOOKUP_ALWAYS |
 342                                              HAMMER2_LOOKUP_SHARED);
 343                 error = chain ? chain->error : 0;
 344         } else {
 345                 error = EIO;
 346                 chain = NULL;
 347         }
 348         TIMER(2);
 349         error = hammer2_xop_feed(&xop->head, chain, clindex, error);
 350         TIMER(3);
 351         if (chain) {
 352                 hammer2_chain_unlock(chain);
 353                 hammer2_chain_drop(chain);
 354         }
 355         if (parent) {
 356                 hammer2_chain_unlock(parent);
 357                 hammer2_chain_drop(parent);
 358         }
 359         chain = NULL;   /* safety */
 360         parent = NULL;  /* safety */
 361         TIMER(4);
 362
 363         /*
 364          * Race to finish the frontend
 365          */
 366         if (xop->finished)
 367                 return;
 368         hammer2_mtx_ex(&xop->lock);
 369         if (xop->finished) {
 370                 hammer2_mtx_unlock(&xop->lock);
 371                 return;
 372         }
 373
 374         /*
 375          * Async operation has not completed and we now own the lock.
 376          * Determine if we can complete the operation by issuing the
 377          * frontend collection non-blocking.
 378          *
 379          * H2 double-buffers the data, setting B_NOTMETA on the logical
 380          * buffer hints to the OS that the logical buffer should not be
 381          * swapcached (since the device buffer can be).
 382          *
 383          * Also note that even for compressed data we would rather the
 384          * kernel cache/swapcache device buffers more and (decompressed)
 385          * logical buffers less, since that will significantly improve
 386          * the amount of end-user data that can be cached.
 387          */
 388         error = hammer2_xop_collect(&xop->head, HAMMER2_XOP_COLLECT_NOWAIT);
 389         TIMER(5);
 390
 391         switch(error) {
 392         case 0:
 393                 xop->finished = 1;
 394                 hammer2_mtx_unlock(&xop->lock);
 395                 bp->b_flags |= B_NOTMETA;
 396                 chain = xop->head.cluster.focus;
 397                 hammer2_strategy_read_completion(chain, (char *)chain->data,
 398                                                  xop->bio);
 399                 biodone(bio);
 400                 hammer2_xop_retire(&xop->head, HAMMER2_XOPMASK_VOP);
 401                 break;
 402         case ENOENT:
 403                 xop->finished = 1;
 404                 hammer2_mtx_unlock(&xop->lock);
 405                 bp->b_flags |= B_NOTMETA;
 406                 bp->b_resid = 0;
 407                 bp->b_error = 0;
 408                 bzero(bp->b_data, bp->b_bcount);
 409                 biodone(bio);
 410                 hammer2_xop_retire(&xop->head, HAMMER2_XOPMASK_VOP);
 411                 break;
 412         case EINPROGRESS:
 413                 hammer2_mtx_unlock(&xop->lock);
 414                 break;
 415         default:
 416                 kprintf("strategy_xop_read: error %d loff=%016jx\n",
 417                         error, bp->b_loffset);
 418                 xop->finished = 1;
 419                 hammer2_mtx_unlock(&xop->lock);
 420                 bp->b_flags |= B_ERROR;
 421                 bp->b_error = EIO;
 422                 biodone(bio);
 423                 hammer2_xop_retire(&xop->head, HAMMER2_XOPMASK_VOP);
 424                 break;
 425         }
 426         TIMER(6);
 427 }
 428
 429 static
 430 void
 431 hammer2_strategy_read_completion(hammer2_chain_t *chain, char *data,
 432                                  struct bio *bio)
 433 {
 434         struct buf *bp = bio->bio_buf;
 435
 436         if (chain->bref.type == HAMMER2_BREF_TYPE_INODE) {
 437                 /*
 438                  * Data is embedded in the inode (copy from inode).
 439                  */
 440                 bcopy(((hammer2_inode_data_t *)data)->u.data,
 441                       bp->b_data, HAMMER2_EMBEDDED_BYTES);
 442                 bzero(bp->b_data + HAMMER2_EMBEDDED_BYTES,
 443                       bp->b_bcount - HAMMER2_EMBEDDED_BYTES);
 444                 bp->b_resid = 0;
 445                 bp->b_error = 0;
 446         } else if (chain->bref.type == HAMMER2_BREF_TYPE_DATA) {
 447                 /*
 448                  * Data is on-media, record for live dedup.  Release the
 449                  * chain (try to free it) when done.  The data is still
 450                  * cached by both the buffer cache in front and the
 451                  * block device behind us.  This leaves more room in the
 452                  * LRU chain cache for meta-data chains which we really
 453                  * want to retain.
 454                  */
 455                 hammer2_dedup_record(chain, data);
 456                 atomic_set_int(&chain->flags, HAMMER2_CHAIN_RELEASE);
 457
 458                 /*
 459                  * Decompression and copy.
 460                  */
 461                 switch (HAMMER2_DEC_COMP(chain->bref.methods)) {
 462                 case HAMMER2_COMP_LZ4:
 463                         hammer2_decompress_LZ4_callback(data, chain->bytes,
 464                                                         bio);
 465                         /* b_resid set by call */
 466                         break;
 467                 case HAMMER2_COMP_ZLIB:
 468                         hammer2_decompress_ZLIB_callback(data, chain->bytes,
 469                                                          bio);
 470                         /* b_resid set by call */
 471                         break;
 472                 case HAMMER2_COMP_NONE:
 473                         KKASSERT(chain->bytes <= bp->b_bcount);
 474                         bcopy(data, bp->b_data, chain->bytes);
 475                         if (chain->bytes < bp->b_bcount) {
 476                                 bzero(bp->b_data + chain->bytes,
 477                                       bp->b_bcount - chain->bytes);
 478                         }
 479                         bp->b_resid = 0;
 480                         bp->b_error = 0;
 481                         break;
 482                 default:
 483                         panic("hammer2_strategy_read: "
 484                               "unknown compression type");
 485                 }
 486         } else {
 487                 panic("hammer2_strategy_read: unknown bref type");
 488         }
 489 }
 490
 491 /****************************************************************************
 492  *                              WRITE SUPPORT                               *
 493  ****************************************************************************/
 494
 495 /*
 496  * Functions for compression in threads,
 497  * from hammer2_vnops.c
 498  */
 499 static void hammer2_write_file_core(struct buf *bp, hammer2_inode_t *ip,
 500                                 hammer2_chain_t **parentp,
 501                                 hammer2_key_t lbase, int ioflag, int pblksize,
 502                                 hammer2_tid_t mtid, int *errorp);
 503 static void hammer2_compress_and_write(struct buf *bp, hammer2_inode_t *ip,
 504                                 hammer2_chain_t **parentp,
 505                                 hammer2_key_t lbase, int ioflag, int pblksize,
 506                                 hammer2_tid_t mtid, int *errorp,
 507                                 int comp_algo, int check_algo);
 508 static void hammer2_zero_check_and_write(struct buf *bp, hammer2_inode_t *ip,
 509                                 hammer2_chain_t **parentp,
 510                                 hammer2_key_t lbase, int ioflag, int pblksize,
 511                                 hammer2_tid_t mtid, int *errorp,
 512                                 int check_algo);
 513 static int test_block_zeros(const char *buf, size_t bytes);
 514 static void zero_write(struct buf *bp, hammer2_inode_t *ip,
 515                                 hammer2_chain_t **parentp,
 516                                 hammer2_key_t lbase,
 517                                 hammer2_tid_t mtid, int *errorp);
 518 static void hammer2_write_bp(hammer2_chain_t *chain, struct buf *bp,
 519                                 int ioflag, int pblksize,
 520                                 hammer2_tid_t mtid, int *errorp,
 521                                 int check_algo);
 522
 523 static
 524 int
 525 hammer2_strategy_write(struct vop_strategy_args *ap)
 526 {
 527         hammer2_xop_strategy_t *xop;
 528         hammer2_pfs_t *pmp;
 529         struct bio *bio;
 530         struct buf *bp;
 531         hammer2_inode_t *ip;
 532
 533         bio = ap->a_bio;
 534         bp = bio->bio_buf;
 535         ip = VTOI(ap->a_vp);
 536         pmp = ip->pmp;
 537
 538         hammer2_lwinprog_ref(pmp);
 539         hammer2_trans_assert_strategy(pmp);
 540         hammer2_trans_init(pmp, HAMMER2_TRANS_BUFCACHE);
 541
 542         xop = hammer2_xop_alloc(ip, HAMMER2_XOP_MODIFYING);
 543         xop->finished = 0;
 544         xop->bio = bio;
 545         xop->lbase = bio->bio_offset;
 546         hammer2_mtx_init(&xop->lock, "h2biow");
 547         hammer2_xop_start(&xop->head, hammer2_strategy_xop_write);
 548         /* asynchronous completion */
 549
 550         hammer2_lwinprog_wait(pmp, hammer2_flush_pipe);
 551
 552         return(0);
 553 }
 554
 555 /*
 556  * Per-node XOP (threaded).  Write the logical buffer to the media.
 557  */
 558 static
 559 void
 560 hammer2_strategy_xop_write(hammer2_xop_t *arg, int clindex)
 561 {
 562         hammer2_xop_strategy_t *xop = &arg->xop_strategy;
 563         hammer2_chain_t *parent;
 564         hammer2_key_t lbase;
 565         hammer2_inode_t *ip;
 566         struct bio *bio;
 567         struct buf *bp;
 568         int error;
 569         int lblksize;
 570         int pblksize;
 571
 572         lbase = xop->lbase;
 573         bio = xop->bio;
 574         bp = bio->bio_buf;
 575         ip = xop->head.ip1;
 576
 577         /* hammer2_trans_init(parent->hmp->spmp, HAMMER2_TRANS_BUFCACHE); */
 578
 579         lblksize = hammer2_calc_logical(ip, bio->bio_offset, &lbase, NULL);
 580         pblksize = hammer2_calc_physical(ip, lbase);
 581         parent = hammer2_inode_chain(ip, clindex, HAMMER2_RESOLVE_ALWAYS);
 582         hammer2_write_file_core(bp, ip, &parent,
 583                                 lbase, IO_ASYNC, pblksize,
 584                                 xop->head.mtid, &error);
 585         if (parent) {
 586                 hammer2_chain_unlock(parent);
 587                 hammer2_chain_drop(parent);
 588                 parent = NULL;  /* safety */
 589         }
 590         hammer2_xop_feed(&xop->head, NULL, clindex, error);
 591
 592         /*
 593          * Race to finish the frontend
 594          */
 595         if (xop->finished)
 596                 return;
 597         hammer2_mtx_ex(&xop->lock);
 598         if (xop->finished) {
 599                 hammer2_mtx_unlock(&xop->lock);
 600                 return;
 601         }
 602
 603         /*
 604          * Async operation has not completed and we now own the lock.
 605          * Determine if we can complete the operation by issuing the
 606          * frontend collection non-blocking.
 607          *
 608          * H2 double-buffers the data, setting B_NOTMETA on the logical
 609          * buffer hints to the OS that the logical buffer should not be
 610          * swapcached (since the device buffer can be).
 611          */
 612         error = hammer2_xop_collect(&xop->head, HAMMER2_XOP_COLLECT_NOWAIT);
 613
 614         if (error == EINPROGRESS) {
 615                 hammer2_mtx_unlock(&xop->lock);
 616                 return;
 617         }
 618
 619         /*
 620          * Async operation has completed.
 621          */
 622         xop->finished = 1;
 623         hammer2_mtx_unlock(&xop->lock);
 624
 625         if (error == ENOENT || error == 0) {
 626                 bp->b_flags |= B_NOTMETA;
 627                 bp->b_resid = 0;
 628                 bp->b_error = 0;
 629                 biodone(bio);
 630         } else {
 631                 kprintf("strategy_xop_write: error %d loff=%016jx\n",
 632                         error, bp->b_loffset);
 633                 bp->b_flags |= B_ERROR;
 634                 bp->b_error = EIO;
 635                 biodone(bio);
 636         }
 637         hammer2_xop_retire(&xop->head, HAMMER2_XOPMASK_VOP);
 638         hammer2_trans_assert_strategy(ip->pmp);
 639         hammer2_lwinprog_drop(ip->pmp);
 640         hammer2_trans_done(ip->pmp);
 641 }
 642
 643 /*
 644  * Wait for pending I/O to complete
 645  */
 646 void
 647 hammer2_bioq_sync(hammer2_pfs_t *pmp)
 648 {
 649         hammer2_lwinprog_wait(pmp, 0);
 650 }
 651
 652 /*
 653  * Create a new cluster at (cparent, lbase) and assign physical storage,
 654  * returning a cluster suitable for I/O.  The cluster will be in a modified
 655  * state.
 656  *
 657  * cparent can wind up being anything.
 658  *
 659  * If datap is not NULL, *datap points to the real data we intend to write.
 660  * If we can dedup the storage location we set *datap to NULL to indicate
 661  * to the caller that a dedup occurred.
 662  *
 663  * NOTE: Special case for data embedded in inode.
 664  */
 665 static
 666 hammer2_chain_t *
 667 hammer2_assign_physical(hammer2_inode_t *ip, hammer2_chain_t **parentp,
 668                         hammer2_key_t lbase, int pblksize,
 669                         hammer2_tid_t mtid, char **datap, int *errorp)
 670 {
 671         hammer2_chain_t *chain;
 672         hammer2_key_t key_dummy;
 673         hammer2_off_t dedup_off;
 674         int pradix = hammer2_getradix(pblksize);
 675         int cache_index = -1;
 676
 677         /*
 678          * Locate the chain associated with lbase, return a locked chain.
 679          * However, do not instantiate any data reference (which utilizes a
 680          * device buffer) because we will be using direct IO via the
 681          * logical buffer cache buffer.
 682          */
 683         *errorp = 0;
 684         KKASSERT(pblksize >= HAMMER2_ALLOC_MIN);
 685 retry:
 686         TIMER(30);
 687         chain = hammer2_chain_lookup(parentp, &key_dummy,
 688                                      lbase, lbase,
 689                                      &cache_index,
 690                                      HAMMER2_LOOKUP_NODATA);
 691
 692         /*
 693          * The lookup code should not return a DELETED chain to us, unless
 694          * its a short-file embedded in the inode.  Then it is possible for
 695          * the lookup to return a deleted inode.
 696          */
 697         if (chain && (chain->flags & HAMMER2_CHAIN_DELETED) &&
 698             chain->bref.type != HAMMER2_BREF_TYPE_INODE) {
 699                 kprintf("assign physical deleted chain @ "
 700                         "%016jx (%016jx.%02x) ip %016jx\n",
 701                         lbase, chain->bref.data_off, chain->bref.type,
 702                         ip->meta.inum);
 703                 Debugger("bleh");
 704         }
 705
 706         if (chain == NULL) {
 707                 /*
 708                  * We found a hole, create a new chain entry.
 709                  *
 710                  * NOTE: DATA chains are created without device backing
 711                  *       store (nor do we want any).
 712                  */
 713                 dedup_off = hammer2_dedup_lookup((*parentp)->hmp, datap,
 714                                                  pblksize);
 715                 *errorp = hammer2_chain_create(parentp, &chain,
 716                                                ip->pmp,
 717                                        HAMMER2_ENC_CHECK(ip->meta.check_algo) |
 718                                        HAMMER2_ENC_COMP(HAMMER2_COMP_NONE),
 719                                                lbase, HAMMER2_PBUFRADIX,
 720                                                HAMMER2_BREF_TYPE_DATA,
 721                                                pblksize, mtid,
 722                                                dedup_off, 0);
 723                 if (chain == NULL) {
 724                         panic("hammer2_chain_create: par=%p error=%d\n",
 725                               *parentp, *errorp);
 726                         goto retry;
 727                 }
 728                 /*ip->delta_dcount += pblksize;*/
 729         } else {
 730                 switch (chain->bref.type) {
 731                 case HAMMER2_BREF_TYPE_INODE:
 732                         /*
 733                          * The data is embedded in the inode, which requires
 734                          * a bit more finess.
 735                          */
 736                         hammer2_chain_modify_ip(ip, chain, mtid, 0);
 737                         break;
 738                 case HAMMER2_BREF_TYPE_DATA:
 739                         dedup_off = hammer2_dedup_lookup(chain->hmp, datap,
 740                                                          pblksize);
 741                         if (chain->bytes != pblksize) {
 742                                 hammer2_chain_resize(ip, *parentp, chain,
 743                                                      mtid, dedup_off,
 744                                                      pradix,
 745                                                      HAMMER2_MODIFY_OPTDATA);
 746                         }
 747
 748                         /*
 749                          * DATA buffers must be marked modified whether the
 750                          * data is in a logical buffer or not.  We also have
 751                          * to make this call to fixup the chain data pointers
 752                          * after resizing in case this is an encrypted or
 753                          * compressed buffer.
 754                          */
 755                         hammer2_chain_modify(chain, mtid, dedup_off,
 756                                              HAMMER2_MODIFY_OPTDATA);
 757                         break;
 758                 default:
 759                         panic("hammer2_assign_physical: bad type");
 760                         /* NOT REACHED */
 761                         break;
 762                 }
 763         }
 764         TIMER(31);
 765         return (chain);
 766 }
 767
 768 /*
 769  * hammer2_write_file_core() - hammer2_write_thread() helper
 770  *
 771  * The core write function which determines which path to take
 772  * depending on compression settings.  We also have to locate the
 773  * related chains so we can calculate and set the check data for
 774  * the blockref.
 775  */
 776 static
 777 void
 778 hammer2_write_file_core(struct buf *bp, hammer2_inode_t *ip,
 779                         hammer2_chain_t **parentp,
 780                         hammer2_key_t lbase, int ioflag, int pblksize,
 781                         hammer2_tid_t mtid, int *errorp)
 782 {
 783         hammer2_chain_t *chain;
 784         char *data = bp->b_data;
 785
 786         *errorp = 0;
 787
 788         switch(HAMMER2_DEC_ALGO(ip->meta.comp_algo)) {
 789         case HAMMER2_COMP_NONE:
 790                 /*
 791                  * We have to assign physical storage to the buffer
 792                  * we intend to dirty or write now to avoid deadlocks
 793                  * in the strategy code later.
 794                  *
 795                  * This can return NOOFFSET for inode-embedded data.
 796                  * The strategy code will take care of it in that case.
 797                  */
 798                 chain = hammer2_assign_physical(ip, parentp, lbase, pblksize,
 799                                                 mtid, &data, errorp);
 800                 if (chain->bref.type == HAMMER2_BREF_TYPE_INODE) {
 801                         hammer2_inode_data_t *wipdata;
 802
 803                         wipdata = &chain->data->ipdata;
 804                         KKASSERT(wipdata->meta.op_flags &
 805                                  HAMMER2_OPFLAG_DIRECTDATA);
 806                         KKASSERT(bp->b_loffset == 0);
 807                         bcopy(bp->b_data, wipdata->u.data,
 808                               HAMMER2_EMBEDDED_BYTES);
 809                         ++hammer2_iod_file_wembed;
 810                 } else if (data == NULL) {
 811                         /*
 812                          * Copy of data already present on-media.
 813                          */
 814                         chain->bref.methods =
 815                                 HAMMER2_ENC_COMP(HAMMER2_COMP_NONE) +
 816                                 HAMMER2_ENC_CHECK(ip->meta.check_algo);
 817                         hammer2_chain_setcheck(chain, bp->b_data);
 818                 } else {
 819                         hammer2_write_bp(chain, bp, ioflag, pblksize,
 820                                          mtid, errorp, ip->meta.check_algo);
 821                 }
 822                 if (chain) {
 823                         hammer2_chain_unlock(chain);
 824                         hammer2_chain_drop(chain);
 825                 }
 826                 break;
 827         case HAMMER2_COMP_AUTOZERO:
 828                 /*
 829                  * Check for zero-fill only
 830                  */
 831                 hammer2_zero_check_and_write(bp, ip, parentp,
 832                                              lbase, ioflag, pblksize,
 833                                              mtid, errorp,
 834                                              ip->meta.check_algo);
 835                 break;
 836         case HAMMER2_COMP_LZ4:
 837         case HAMMER2_COMP_ZLIB:
 838         default:
 839                 /*
 840                  * Check for zero-fill and attempt compression.
 841                  */
 842                 hammer2_compress_and_write(bp, ip, parentp,
 843                                            lbase, ioflag, pblksize,
 844                                            mtid, errorp,
 845                                            ip->meta.comp_algo,
 846                                            ip->meta.check_algo);
 847                 break;
 848         }
 849 }
 850
 851 /*
 852  * Helper
 853  *
 854  * Generic function that will perform the compression in compression
 855  * write path. The compression algorithm is determined by the settings
 856  * obtained from inode.
 857  */
 858 static
 859 void
 860 hammer2_compress_and_write(struct buf *bp, hammer2_inode_t *ip,
 861         hammer2_chain_t **parentp,
 862         hammer2_key_t lbase, int ioflag, int pblksize,
 863         hammer2_tid_t mtid, int *errorp, int comp_algo, int check_algo)
 864 {
 865         hammer2_chain_t *chain;
 866         int comp_size;
 867         int comp_block_size;
 868         char *comp_buffer;
 869         char *data;
 870
 871         if (test_block_zeros(bp->b_data, pblksize)) {
 872                 zero_write(bp, ip, parentp, lbase, mtid, errorp);
 873                 return;
 874         }
 875
 876         comp_size = 0;
 877         comp_buffer = NULL;
 878
 879         KKASSERT(pblksize / 2 <= 32768);
 880
 881         if (ip->comp_heuristic < 8 || (ip->comp_heuristic & 7) == 0) {
 882                 z_stream strm_compress;
 883                 int comp_level;
 884                 int ret;
 885
 886                 switch(HAMMER2_DEC_ALGO(comp_algo)) {
 887                 case HAMMER2_COMP_LZ4:
 888                         comp_buffer = objcache_get(cache_buffer_write,
 889                                                    M_INTWAIT);
 890                         comp_size = LZ4_compress_limitedOutput(
 891                                         bp->b_data,
 892                                         &comp_buffer[sizeof(int)],
 893                                         pblksize,
 894                                         pblksize / 2 - sizeof(int));
 895                         /*
 896                          * We need to prefix with the size, LZ4
 897                          * doesn't do it for us.  Add the related
 898                          * overhead.
 899                          */
 900                         *(int *)comp_buffer = comp_size;
 901                         if (comp_size)
 902                                 comp_size += sizeof(int);
 903                         break;
 904                 case HAMMER2_COMP_ZLIB:
 905                         comp_level = HAMMER2_DEC_LEVEL(comp_algo);
 906                         if (comp_level == 0)
 907                                 comp_level = 6; /* default zlib compression */
 908                         else if (comp_level < 6)
 909                                 comp_level = 6;
 910                         else if (comp_level > 9)
 911                                 comp_level = 9;
 912                         ret = deflateInit(&strm_compress, comp_level);
 913                         if (ret != Z_OK) {
 914                                 kprintf("HAMMER2 ZLIB: fatal error "
 915                                         "on deflateInit.\n");
 916                         }
 917
 918                         comp_buffer = objcache_get(cache_buffer_write,
 919                                                    M_INTWAIT);
 920                         strm_compress.next_in = bp->b_data;
 921                         strm_compress.avail_in = pblksize;
 922                         strm_compress.next_out = comp_buffer;
 923                         strm_compress.avail_out = pblksize / 2;
 924                         ret = deflate(&strm_compress, Z_FINISH);
 925                         if (ret == Z_STREAM_END) {
 926                                 comp_size = pblksize / 2 -
 927                                             strm_compress.avail_out;
 928                         } else {
 929                                 comp_size = 0;
 930                         }
 931                         ret = deflateEnd(&strm_compress);
 932                         break;
 933                 default:
 934                         kprintf("Error: Unknown compression method.\n");
 935                         kprintf("Comp_method = %d.\n", comp_algo);
 936                         break;
 937                 }
 938         }
 939
 940         if (comp_size == 0) {
 941                 /*
 942                  * compression failed or turned off
 943                  */
 944                 comp_block_size = pblksize;     /* safety */
 945                 if (++ip->comp_heuristic > 128)
 946                         ip->comp_heuristic = 8;
 947         } else {
 948                 /*
 949                  * compression succeeded
 950                  */
 951                 ip->comp_heuristic = 0;
 952                 if (comp_size <= 1024) {
 953                         comp_block_size = 1024;
 954                 } else if (comp_size <= 2048) {
 955                         comp_block_size = 2048;
 956                 } else if (comp_size <= 4096) {
 957                         comp_block_size = 4096;
 958                 } else if (comp_size <= 8192) {
 959                         comp_block_size = 8192;
 960                 } else if (comp_size <= 16384) {
 961                         comp_block_size = 16384;
 962                 } else if (comp_size <= 32768) {
 963                         comp_block_size = 32768;
 964                 } else {
 965                         panic("hammer2: WRITE PATH: "
 966                               "Weird comp_size value.");
 967                         /* NOT REACHED */
 968                         comp_block_size = pblksize;
 969                 }
 970
 971                 /*
 972                  * Must zero the remainder or dedup (which operates on a
 973                  * physical block basis) will not find matches.
 974                  */
 975                 if (comp_size < comp_block_size) {
 976                         bzero(comp_buffer + comp_size,
 977                               comp_block_size - comp_size);
 978                 }
 979         }
 980
 981         /*
 982          * Assign physical storage, data will be set to NULL if a live-dedup
 983          * was successful.
 984          */
 985         data = comp_size ? comp_buffer : bp->b_data;
 986         chain = hammer2_assign_physical(ip, parentp, lbase, comp_block_size,
 987                                         mtid, &data, errorp);
 988
 989         if (*errorp) {
 990                 kprintf("WRITE PATH: An error occurred while "
 991                         "assigning physical space.\n");
 992                 KKASSERT(chain == NULL);
 993                 goto done;
 994         }
 995
 996         if (chain->bref.type == HAMMER2_BREF_TYPE_INODE) {
 997                 hammer2_inode_data_t *wipdata;
 998
 999                 hammer2_chain_modify_ip(ip, chain, mtid, 0);
1000                 wipdata = &chain->data->ipdata;
1001                 KKASSERT(wipdata->meta.op_flags & HAMMER2_OPFLAG_DIRECTDATA);
1002                 KKASSERT(bp->b_loffset == 0);
1003                 bcopy(bp->b_data, wipdata->u.data, HAMMER2_EMBEDDED_BYTES);
1004                 ++hammer2_iod_file_wembed;
1005         } else if (data == NULL) {
1006                 /*
1007                  * Live deduplication, a copy of the data is already present
1008                  * on the media.
1009                  */
1010                 char *bdata;
1011
1012                 if (comp_size) {
1013                         chain->bref.methods =
1014                                 HAMMER2_ENC_COMP(comp_algo) +
1015                                 HAMMER2_ENC_CHECK(check_algo);
1016                 } else {
1017                         chain->bref.methods =
1018                                 HAMMER2_ENC_COMP(
1019                                         HAMMER2_COMP_NONE) +
1020                                 HAMMER2_ENC_CHECK(check_algo);
1021                 }
1022                 bdata = comp_size ? comp_buffer : bp->b_data;
1023                 hammer2_chain_setcheck(chain, bdata);
1024                 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_INITIAL);
1025         } else {
1026                 hammer2_io_t *dio;
1027                 char *bdata;
1028
1029                 KKASSERT(chain->flags & HAMMER2_CHAIN_MODIFIED);
1030
1031                 switch(chain->bref.type) {
1032                 case HAMMER2_BREF_TYPE_INODE:
1033                         panic("hammer2_write_bp: unexpected inode\n");
1034                         break;
1035                 case HAMMER2_BREF_TYPE_DATA:
1036                         /*
1037                          * Optimize out the read-before-write
1038                          * if possible.
1039                          */
1040                         *errorp = hammer2_io_newnz(chain->hmp,
1041                                                    chain->bref.type,
1042                                                    chain->bref.data_off,
1043                                                    chain->bytes,
1044                                                    &dio);
1045                         if (*errorp) {
1046                                 hammer2_io_brelse(&dio);
1047                                 kprintf("hammer2: WRITE PATH: "
1048                                         "dbp bread error\n");
1049                                 break;
1050                         }
1051                         bdata = hammer2_io_data(dio, chain->bref.data_off);
1052
1053                         /*
1054                          * When loading the block make sure we don't
1055                          * leave garbage after the compressed data.
1056                          */
1057                         if (comp_size) {
1058                                 chain->bref.methods =
1059                                         HAMMER2_ENC_COMP(comp_algo) +
1060                                         HAMMER2_ENC_CHECK(check_algo);
1061                                 bcopy(comp_buffer, bdata, comp_size);
1062                         } else {
1063                                 chain->bref.methods =
1064                                         HAMMER2_ENC_COMP(
1065                                                 HAMMER2_COMP_NONE) +
1066                                         HAMMER2_ENC_CHECK(check_algo);
1067                                 bcopy(bp->b_data, bdata, pblksize);
1068                         }
1069
1070                         /*
1071                          * The flush code doesn't calculate check codes for
1072                          * file data (doing so can result in excessive I/O),
1073                          * so we do it here.
1074                          */
1075                         hammer2_chain_setcheck(chain, bdata);
1076                         hammer2_dedup_record(chain, bdata);
1077
1078                         /*
1079                          * Device buffer is now valid, chain is no longer in
1080                          * the initial state.
1081                          *
1082                          * (No blockref table worries with file data)
1083                          */
1084                         atomic_clear_int(&chain->flags, HAMMER2_CHAIN_INITIAL);
1085
1086                         /* Now write the related bdp. */
1087                         if (ioflag & IO_SYNC) {
1088                                 /*
1089                                  * Synchronous I/O requested.
1090                                  */
1091                                 hammer2_io_bwrite(&dio);
1092                         /*
1093                         } else if ((ioflag & IO_DIRECT) &&
1094                                    loff + n == pblksize) {
1095                                 hammer2_io_bdwrite(&dio);
1096                         */
1097                         } else if (ioflag & IO_ASYNC) {
1098                                 hammer2_io_bawrite(&dio);
1099                         } else {
1100                                 hammer2_io_bdwrite(&dio);
1101                         }
1102                         break;
1103                 default:
1104                         panic("hammer2_write_bp: bad chain type %d\n",
1105                                 chain->bref.type);
1106                         /* NOT REACHED */
1107                         break;
1108                 }
1109         }
1110 done:
1111         if (chain) {
1112                 hammer2_chain_unlock(chain);
1113                 hammer2_chain_drop(chain);
1114         }
1115         if (comp_buffer)
1116                 objcache_put(cache_buffer_write, comp_buffer);
1117 }
1118
1119 /*
1120  * Helper
1121  *
1122  * Function that performs zero-checking and writing without compression,
1123  * it corresponds to default zero-checking path.
1124  */
1125 static
1126 void
1127 hammer2_zero_check_and_write(struct buf *bp, hammer2_inode_t *ip,
1128         hammer2_chain_t **parentp,
1129         hammer2_key_t lbase, int ioflag, int pblksize,
1130         hammer2_tid_t mtid, int *errorp,
1131         int check_algo)
1132 {
1133         hammer2_chain_t *chain;
1134         char *data = bp->b_data;
1135
1136         if (test_block_zeros(bp->b_data, pblksize)) {
1137                 zero_write(bp, ip, parentp, lbase, mtid, errorp);
1138         } else {
1139                 chain = hammer2_assign_physical(ip, parentp, lbase, pblksize,
1140                                                 mtid, &data, errorp);
1141                 if (data) {
1142                         hammer2_write_bp(chain, bp, ioflag, pblksize,
1143                                          mtid, errorp, check_algo);
1144                 } /* else dedup occurred */
1145                 if (chain) {
1146                         hammer2_chain_unlock(chain);
1147                         hammer2_chain_drop(chain);
1148                 }
1149         }
1150 }
1151
1152 /*
1153  * Helper
1154  *
1155  * A function to test whether a block of data contains only zeros,
1156  * returns TRUE (non-zero) if the block is all zeros.
1157  */
1158 static
1159 int
1160 test_block_zeros(const char *buf, size_t bytes)
1161 {
1162         size_t i;
1163
1164         for (i = 0; i < bytes; i += sizeof(long)) {
1165                 if (*(const long *)(buf + i) != 0)
1166                         return (0);
1167         }
1168         return (1);
1169 }
1170
1171 /*
1172  * Helper
1173  *
1174  * Function to "write" a block that contains only zeros.
1175  */
1176 static
1177 void
1178 zero_write(struct buf *bp, hammer2_inode_t *ip,
1179            hammer2_chain_t **parentp,
1180            hammer2_key_t lbase, hammer2_tid_t mtid, int *errorp)
1181 {
1182         hammer2_chain_t *chain;
1183         hammer2_key_t key_dummy;
1184         int cache_index = -1;
1185
1186         *errorp = 0;
1187         chain = hammer2_chain_lookup(parentp, &key_dummy,
1188                                      lbase, lbase,
1189                                      &cache_index,
1190                                      HAMMER2_LOOKUP_NODATA);
1191         if (chain) {
1192                 if (chain->bref.type == HAMMER2_BREF_TYPE_INODE) {
1193                         hammer2_inode_data_t *wipdata;
1194
1195                         hammer2_chain_modify_ip(ip, chain, mtid, 0);
1196                         wipdata = &chain->data->ipdata;
1197                         KKASSERT(wipdata->meta.op_flags &
1198                                  HAMMER2_OPFLAG_DIRECTDATA);
1199                         KKASSERT(bp->b_loffset == 0);
1200                         bzero(wipdata->u.data, HAMMER2_EMBEDDED_BYTES);
1201                         ++hammer2_iod_file_wembed;
1202                 } else {
1203                         hammer2_chain_delete(*parentp, chain,
1204                                              mtid, HAMMER2_DELETE_PERMANENT);
1205                         ++hammer2_iod_file_wzero;
1206                 }
1207                 hammer2_chain_unlock(chain);
1208                 hammer2_chain_drop(chain);
1209         } else {
1210                 ++hammer2_iod_file_wzero;
1211         }
1212 }
1213
1214 /*
1215  * Helper
1216  *
1217  * Function to write the data as it is, without performing any sort of
1218  * compression. This function is used in path without compression and
1219  * default zero-checking path.
1220  */
1221 static
1222 void
1223 hammer2_write_bp(hammer2_chain_t *chain, struct buf *bp, int ioflag,
1224                  int pblksize,
1225                  hammer2_tid_t mtid, int *errorp, int check_algo)
1226 {
1227         hammer2_inode_data_t *wipdata;
1228         hammer2_io_t *dio;
1229         char *bdata;
1230         int error;
1231
1232         error = 0;      /* XXX TODO below */
1233
1234         KKASSERT(chain->flags & HAMMER2_CHAIN_MODIFIED);
1235
1236         switch(chain->bref.type) {
1237         case HAMMER2_BREF_TYPE_INODE:
1238                 wipdata = &chain->data->ipdata;
1239                 KKASSERT(wipdata->meta.op_flags & HAMMER2_OPFLAG_DIRECTDATA);
1240                 KKASSERT(bp->b_loffset == 0);
1241                 bcopy(bp->b_data, wipdata->u.data, HAMMER2_EMBEDDED_BYTES);
1242                 error = 0;
1243                 ++hammer2_iod_file_wembed;
1244                 break;
1245         case HAMMER2_BREF_TYPE_DATA:
1246                 error = hammer2_io_newnz(chain->hmp,
1247                                          chain->bref.type,
1248                                          chain->bref.data_off,
1249                                          chain->bytes, &dio);
1250                 if (error) {
1251                         hammer2_io_bqrelse(&dio);
1252                         kprintf("hammer2: WRITE PATH: "
1253                                 "dbp bread error\n");
1254                         break;
1255                 }
1256                 bdata = hammer2_io_data(dio, chain->bref.data_off);
1257
1258                 chain->bref.methods = HAMMER2_ENC_COMP(HAMMER2_COMP_NONE) +
1259                                       HAMMER2_ENC_CHECK(check_algo);
1260                 bcopy(bp->b_data, bdata, chain->bytes);
1261
1262                 /*
1263                  * The flush code doesn't calculate check codes for
1264                  * file data (doing so can result in excessive I/O),
1265                  * so we do it here.
1266                  */
1267                 hammer2_chain_setcheck(chain, bdata);
1268                 hammer2_dedup_record(chain, bdata);
1269
1270                 /*
1271                  * Device buffer is now valid, chain is no longer in
1272                  * the initial state.
1273                  *
1274                  * (No blockref table worries with file data)
1275                  */
1276                 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_INITIAL);
1277
1278                 if (ioflag & IO_SYNC) {
1279                         /*
1280                          * Synchronous I/O requested.
1281                          */
1282                         hammer2_io_bwrite(&dio);
1283                 /*
1284                 } else if ((ioflag & IO_DIRECT) &&
1285                            loff + n == pblksize) {
1286                         hammer2_io_bdwrite(&dio);
1287                 */
1288                 } else if (ioflag & IO_ASYNC) {
1289                         hammer2_io_bawrite(&dio);
1290                 } else {
1291                         hammer2_io_bdwrite(&dio);
1292                 }
1293                 break;
1294         default:
1295                 panic("hammer2_write_bp: bad chain type %d\n",
1296                       chain->bref.type);
1297                 /* NOT REACHED */
1298                 error = 0;
1299                 break;
1300         }
1301         KKASSERT(error == 0);   /* XXX TODO */
1302         *errorp = error;
1303 }
1304
1305 /*
1306  * LIVE DEDUP HEURISTIC
1307  *
1308  * WARNING! This code is SMP safe but the heuristic allows SMP collisions.
1309  *          All fields must be loaded into locals and validated.
1310  *
1311  * WARNING! Should only be used for file data, hammer2_chain_modify() only
1312  *          checks for the dedup case on data chains.  Also, dedup data can
1313  *          only be recorded for committed chains (so NOT strategy writes
1314  *          which can undergo further modification after the fact!).
1315  */
1316 void
1317 hammer2_dedup_record(hammer2_chain_t *chain, char *data)
1318 {
1319         hammer2_dev_t *hmp;
1320         hammer2_dedup_t *dedup;
1321         uint64_t crc;
1322         int best = 0;
1323         int i;
1324         int dticks;
1325
1326         if (hammer2_dedup_enable == 0)
1327                 return;
1328
1329         /*
1330          * Only committed data can be recorded for de-duplication, otherwise
1331          * the contents may change out from under us.  So, on read if the
1332          * chain is not modified, and on flush when the chain is committed.
1333          */
1334         if ((chain->flags &
1335             (HAMMER2_CHAIN_MODIFIED | HAMMER2_CHAIN_INITIAL)) == 0) {
1336                 return;
1337         }
1338
1339
1340         hmp = chain->hmp;
1341
1342         switch(HAMMER2_DEC_CHECK(chain->bref.methods)) {
1343         case HAMMER2_CHECK_ISCSI32:
1344                 /*
1345                  * XXX use the built-in crc (the dedup lookup sequencing
1346                  * needs to be fixed so the check code is already present
1347                  * when dedup_lookup is called)
1348                  */
1349 #if 0
1350                 crc = (uint64_t)(uint32_t)chain->bref.check.iscsi32.value;
1351 #endif
1352                 crc = XXH64(data, chain->bytes, XXH_HAMMER2_SEED);
1353                 break;
1354         case HAMMER2_CHECK_XXHASH64:
1355                 crc = chain->bref.check.xxhash64.value;
1356                 break;
1357         case HAMMER2_CHECK_SHA192:
1358                 /*
1359                  * XXX use the built-in crc (the dedup lookup sequencing
1360                  * needs to be fixed so the check code is already present
1361                  * when dedup_lookup is called)
1362                  */
1363 #if 0
1364                 crc = ((uint64_t *)chain->bref.check.sha192.data)[0] ^
1365                       ((uint64_t *)chain->bref.check.sha192.data)[1] ^
1366                       ((uint64_t *)chain->bref.check.sha192.data)[2];
1367 #endif
1368                 crc = XXH64(data, chain->bytes, XXH_HAMMER2_SEED);
1369                 break;
1370         default:
1371                 /*
1372                  * Cannot dedup without a check code
1373                  *
1374                  * NOTE: In particular, CHECK_NONE allows a sector to be
1375                  *       overwritten without copy-on-write, recording
1376                  *       a dedup block for a CHECK_NONE object would be
1377                  *       a disaster!
1378                  */
1379                 return;
1380         }
1381         dedup = &hmp->heur_dedup[crc & (HAMMER2_DEDUP_HEUR_MASK & ~3)];
1382         for (i = 0; i < 4; ++i) {
1383                 if (dedup[i].data_crc == crc) {
1384                         best = i;
1385                         break;
1386                 }
1387                 dticks = (int)(dedup[i].ticks - dedup[best].ticks);
1388                 if (dticks < 0 || dticks > hz * 60 * 30)
1389                         best = i;
1390         }
1391         dedup += best;
1392         if (hammer2_debug & 0x40000) {
1393                 kprintf("REC %04x %016jx %016jx\n",
1394                         (int)(dedup - hmp->heur_dedup),
1395                         crc,
1396                         chain->bref.data_off);
1397         }
1398         dedup->ticks = ticks;
1399         dedup->data_off = chain->bref.data_off;
1400         dedup->data_crc = crc;
1401         atomic_set_int(&chain->flags, HAMMER2_CHAIN_DEDUP);
1402 }
1403
1404 static
1405 hammer2_off_t
1406 hammer2_dedup_lookup(hammer2_dev_t *hmp, char **datap, int pblksize)
1407 {
1408         hammer2_dedup_t *dedup;
1409         hammer2_io_t *dio;
1410         hammer2_off_t off;
1411         uint64_t crc;
1412         char *data;
1413         int i;
1414
1415         if (hammer2_dedup_enable == 0)
1416                 return 0;
1417         data = *datap;
1418         if (data == NULL)
1419                 return 0;
1420
1421         /*
1422          * XXX use the built-in crc (the dedup lookup sequencing
1423          * needs to be fixed so the check code is already present
1424          * when dedup_lookup is called)
1425          */
1426         crc = XXH64(data, pblksize, XXH_HAMMER2_SEED);
1427         dedup = &hmp->heur_dedup[crc & (HAMMER2_DEDUP_HEUR_MASK & ~3)];
1428
1429         if (hammer2_debug & 0x40000) {
1430                 kprintf("LOC %04x/4 %016jx\n",
1431                         (int)(dedup - hmp->heur_dedup),
1432                         crc);
1433         }
1434
1435         for (i = 0; i < 4; ++i) {
1436                 off = dedup[i].data_off;
1437                 cpu_ccfence();
1438                 if (dedup[i].data_crc != crc)
1439                         continue;
1440                 if ((1 << (int)(off & HAMMER2_OFF_MASK_RADIX)) != pblksize)
1441                         continue;
1442                 dio = hammer2_io_getquick(hmp, off, pblksize);
1443                 if (dio &&
1444                     bcmp(data, hammer2_io_data(dio, off), pblksize) == 0) {
1445                         /*
1446                          * Make sure the INVALOK flag is cleared to prevent
1447                          * the possibly-dirty bp from being invalidated now
1448                          * that we are using it as part of a de-dup operation.
1449                          */
1450                         if (hammer2_debug & 0x40000) {
1451                                 kprintf("DEDUP SUCCESS %016jx\n",
1452                                         (intmax_t)off);
1453                         }
1454                         atomic_clear_64(&dio->refs, HAMMER2_DIO_INVALOK);
1455                         hammer2_io_putblk(&dio);
1456                         *datap = NULL;
1457                         dedup[i].ticks = ticks; /* update use */
1458                         ++hammer2_iod_file_wdedup;
1459
1460                         return off;             /* RETURN */
1461                 }
1462                 if (dio)
1463                         hammer2_io_putblk(&dio);
1464         }
1465         return 0;
1466 }
1467
1468 /*
1469  * Poof.  Races are ok, if someone gets in and reuses a dedup offset
1470  * before or while we are clearing it they will also recover the freemap
1471  * entry (set it to fully allocated), so a bulkfree race can only set it
1472  * to a possibly-free state.
1473  *
1474  * XXX ok, well, not really sure races are ok but going to run with it
1475  *     for the moment.
1476  */
1477 void
1478 hammer2_dedup_clear(hammer2_dev_t *hmp)
1479 {
1480         int i;
1481
1482         for (i = 0; i < HAMMER2_DEDUP_HEUR_SIZE; ++i) {
1483                 hmp->heur_dedup[i].data_off = 0;
1484                 hmp->heur_dedup[i].ticks = ticks - 1;
1485         }
1486 }