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  * Except for the transaction init (which should normally not block),
  75  * we essentially run the strategy operation asynchronously via a XOP.
  76  *
  77  * WARNING! The XOP deals with buffer synchronization.  It is not synchronized
  78  *          to the current cpu.
  79  *
  80  * XXX This isn't supposed to be able to deadlock against vfs_sync vfsync()
  81  *     calls but it has in the past when multiple flushes are queued.
  82  *
  83  * XXX We currently terminate the transaction once we get a quorum, otherwise
  84  *     the frontend can stall, but this can leave the remaining nodes with
  85  *     a potential flush conflict.  We need to delay flushes on those nodes
  86  *     until running transactions complete separately from the normal
  87  *     transaction sequencing.  FIXME TODO.
  88  */
  89 static void hammer2_strategy_xop_read(hammer2_thread_t *thr,
  90                                 hammer2_xop_t *arg);
  91 static void hammer2_strategy_xop_write(hammer2_thread_t *thr,
  92                                 hammer2_xop_t *arg);
  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
 102 hammer2_vop_strategy(struct vop_strategy_args *ap)
 103 {
 104         struct bio *biop;
 105         struct buf *bp;
 106         int error;
 107
 108         biop = ap->a_bio;
 109         bp = biop->bio_buf;
 110
 111         switch(bp->b_cmd) {
 112         case BUF_CMD_READ:
 113                 error = hammer2_strategy_read(ap);
 114                 ++hammer2_iod_file_read;
 115                 break;
 116         case BUF_CMD_WRITE:
 117                 error = hammer2_strategy_write(ap);
 118                 ++hammer2_iod_file_write;
 119                 break;
 120         default:
 121                 bp->b_error = error = EINVAL;
 122                 bp->b_flags |= B_ERROR;
 123                 biodone(biop);
 124                 break;
 125         }
 126         return (error);
 127 }
 128
 129 /*
 130  * Return the largest contiguous physical disk range for the logical
 131  * request, in bytes.
 132  *
 133  * (struct vnode *vp, off_t loffset, off_t *doffsetp, int *runp, int *runb)
 134  *
 135  * Basically disabled, the logical buffer write thread has to deal with
 136  * buffers one-at-a-time.  Note that this should not prevent cluster_read()
 137  * from reading-ahead, it simply prevents it from trying form a single
 138  * cluster buffer for the logical request.  H2 already uses 64KB buffers!
 139  */
 140 int
 141 hammer2_vop_bmap(struct vop_bmap_args *ap)
 142 {
 143         *ap->a_doffsetp = NOOFFSET;
 144         if (ap->a_runp)
 145                 *ap->a_runp = 0;
 146         if (ap->a_runb)
 147                 *ap->a_runb = 0;
 148         return (EOPNOTSUPP);
 149 }
 150
 151 /****************************************************************************
 152  *                              READ SUPPORT                                *
 153  ****************************************************************************/
 154 /*
 155  * Callback used in read path in case that a block is compressed with LZ4.
 156  */
 157 static
 158 void
 159 hammer2_decompress_LZ4_callback(const char *data, u_int bytes, struct bio *bio)
 160 {
 161         struct buf *bp;
 162         char *compressed_buffer;
 163         int compressed_size;
 164         int result;
 165
 166         bp = bio->bio_buf;
 167
 168 #if 0
 169         if bio->bio_caller_info2.index &&
 170               bio->bio_caller_info1.uvalue32 !=
 171               crc32(bp->b_data, bp->b_bufsize) --- return error
 172 #endif
 173
 174         KKASSERT(bp->b_bufsize <= HAMMER2_PBUFSIZE);
 175         compressed_size = *(const int *)data;
 176         KKASSERT((uint32_t)compressed_size <= bytes - sizeof(int));
 177
 178         compressed_buffer = objcache_get(cache_buffer_read, M_INTWAIT);
 179         result = LZ4_decompress_safe(__DECONST(char *, &data[sizeof(int)]),
 180                                      compressed_buffer,
 181                                      compressed_size,
 182                                      bp->b_bufsize);
 183         if (result < 0) {
 184                 kprintf("READ PATH: Error during decompression."
 185                         "bio %016jx/%d\n",
 186                         (intmax_t)bio->bio_offset, bytes);
 187                 /* make sure it isn't random garbage */
 188                 bzero(compressed_buffer, bp->b_bufsize);
 189         }
 190         KKASSERT(result <= bp->b_bufsize);
 191         bcopy(compressed_buffer, bp->b_data, bp->b_bufsize);
 192         if (result < bp->b_bufsize)
 193                 bzero(bp->b_data + result, bp->b_bufsize - result);
 194         objcache_put(cache_buffer_read, compressed_buffer);
 195         bp->b_resid = 0;
 196         bp->b_flags |= B_AGE;
 197 }
 198
 199 /*
 200  * Callback used in read path in case that a block is compressed with ZLIB.
 201  * It is almost identical to LZ4 callback, so in theory they can be unified,
 202  * but we didn't want to make changes in bio structure for that.
 203  */
 204 static
 205 void
 206 hammer2_decompress_ZLIB_callback(const char *data, u_int bytes, struct bio *bio)
 207 {
 208         struct buf *bp;
 209         char *compressed_buffer;
 210         z_stream strm_decompress;
 211         int result;
 212         int ret;
 213
 214         bp = bio->bio_buf;
 215
 216         KKASSERT(bp->b_bufsize <= HAMMER2_PBUFSIZE);
 217         strm_decompress.avail_in = 0;
 218         strm_decompress.next_in = Z_NULL;
 219
 220         ret = inflateInit(&strm_decompress);
 221
 222         if (ret != Z_OK)
 223                 kprintf("HAMMER2 ZLIB: Fatal error in inflateInit.\n");
 224
 225         compressed_buffer = objcache_get(cache_buffer_read, M_INTWAIT);
 226         strm_decompress.next_in = __DECONST(char *, data);
 227
 228         /* XXX supply proper size, subset of device bp */
 229         strm_decompress.avail_in = bytes;
 230         strm_decompress.next_out = compressed_buffer;
 231         strm_decompress.avail_out = bp->b_bufsize;
 232
 233         ret = inflate(&strm_decompress, Z_FINISH);
 234         if (ret != Z_STREAM_END) {
 235                 kprintf("HAMMER2 ZLIB: Fatar error during decompression.\n");
 236                 bzero(compressed_buffer, bp->b_bufsize);
 237         }
 238         bcopy(compressed_buffer, bp->b_data, bp->b_bufsize);
 239         result = bp->b_bufsize - strm_decompress.avail_out;
 240         if (result < bp->b_bufsize)
 241                 bzero(bp->b_data + result, strm_decompress.avail_out);
 242         objcache_put(cache_buffer_read, compressed_buffer);
 243         ret = inflateEnd(&strm_decompress);
 244
 245         bp->b_resid = 0;
 246         bp->b_flags |= B_AGE;
 247 }
 248
 249 /*
 250  * Logical buffer I/O, async read.
 251  */
 252 static
 253 int
 254 hammer2_strategy_read(struct vop_strategy_args *ap)
 255 {
 256         hammer2_xop_strategy_t *xop;
 257         struct buf *bp;
 258         struct bio *bio;
 259         struct bio *nbio;
 260         hammer2_inode_t *ip;
 261         hammer2_key_t lbase;
 262
 263         bio = ap->a_bio;
 264         bp = bio->bio_buf;
 265         ip = VTOI(ap->a_vp);
 266         nbio = push_bio(bio);
 267
 268         lbase = bio->bio_offset;
 269         KKASSERT(((int)lbase & HAMMER2_PBUFMASK) == 0);
 270
 271         xop = hammer2_xop_alloc(ip, HAMMER2_XOP_STRATEGY);
 272         xop->finished = 0;
 273         xop->bio = bio;
 274         xop->lbase = lbase;
 275         hammer2_mtx_init(&xop->lock, "h2bior");
 276         hammer2_xop_start(&xop->head, hammer2_strategy_xop_read);
 277         /* asynchronous completion */
 278
 279         return(0);
 280 }
 281
 282 /*
 283  * Per-node XOP (threaded), do a synchronous lookup of the chain and
 284  * its data.  The frontend is asynchronous, so we are also responsible
 285  * for racing to terminate the frontend.
 286  */
 287 static
 288 void
 289 hammer2_strategy_xop_read(hammer2_thread_t *thr, hammer2_xop_t *arg)
 290 {
 291         hammer2_xop_strategy_t *xop = &arg->xop_strategy;
 292         hammer2_chain_t *parent;
 293         hammer2_chain_t *chain;
 294         hammer2_key_t key_dummy;
 295         hammer2_key_t lbase;
 296         struct bio *bio;
 297         struct buf *bp;
 298         int error;
 299
 300         /*
 301          * Note that we can race completion of the bio supplied by
 302          * the front-end so we cannot access it until we determine
 303          * that we are the ones finishing it up.
 304          */
 305         lbase = xop->lbase;
 306
 307         /*
 308          * This is difficult to optimize.  The logical buffer might be
 309          * partially dirty (contain dummy zero-fill pages), which would
 310          * mess up our crc calculation if we were to try a direct read.
 311          * So for now we always double-buffer through the underlying
 312          * storage.
 313          *
 314          * If not for the above problem we could conditionalize on
 315          * (1) 64KB buffer, (2) one chain (not multi-master) and
 316          * (3) !hammer2_double_buffer, and issue a direct read into the
 317          * logical buffer.
 318          */
 319         parent = hammer2_inode_chain(xop->head.ip1, thr->clindex,
 320                                      HAMMER2_RESOLVE_ALWAYS |
 321                                      HAMMER2_RESOLVE_SHARED);
 322         if (parent) {
 323                 chain = hammer2_chain_lookup(&parent, &key_dummy,
 324                                              lbase, lbase,
 325                                              &error,
 326                                              HAMMER2_LOOKUP_ALWAYS |
 327                                              HAMMER2_LOOKUP_SHARED);
 328                 if (chain)
 329                         error = chain->error;
 330         } else {
 331                 error = HAMMER2_ERROR_EIO;
 332                 chain = NULL;
 333         }
 334         error = hammer2_xop_feed(&xop->head, chain, thr->clindex, error);
 335         if (chain) {
 336                 hammer2_chain_unlock(chain);
 337                 hammer2_chain_drop(chain);
 338         }
 339         if (parent) {
 340                 hammer2_chain_unlock(parent);
 341                 hammer2_chain_drop(parent);
 342         }
 343         chain = NULL;   /* safety */
 344         parent = NULL;  /* safety */
 345
 346         /*
 347          * Race to finish the frontend.  First-to-complete.  bio is only
 348          * valid if we are determined to be the ones able to complete
 349          * the operation.
 350          */
 351         if (xop->finished)
 352                 return;
 353         hammer2_mtx_ex(&xop->lock);
 354         if (xop->finished) {
 355                 hammer2_mtx_unlock(&xop->lock);
 356                 return;
 357         }
 358         bio = xop->bio;
 359         bp = bio->bio_buf;
 360         bkvasync(bp);
 361
 362         /*
 363          * Async operation has not completed and we now own the lock.
 364          * Determine if we can complete the operation by issuing the
 365          * frontend collection non-blocking.
 366          *
 367          * H2 double-buffers the data, setting B_NOTMETA on the logical
 368          * buffer hints to the OS that the logical buffer should not be
 369          * swapcached (since the device buffer can be).
 370          *
 371          * Also note that even for compressed data we would rather the
 372          * kernel cache/swapcache device buffers more and (decompressed)
 373          * logical buffers less, since that will significantly improve
 374          * the amount of end-user data that can be cached.
 375          *
 376          * NOTE: The chain->data for xop->head.cluster.focus will be
 377          *       synchronized to the current cpu by xop_collect(),
 378          *       but other chains in the cluster might not be.
 379          */
 380         error = hammer2_xop_collect(&xop->head, HAMMER2_XOP_COLLECT_NOWAIT);
 381
 382         switch(error) {
 383         case 0:
 384                 xop->finished = 1;
 385                 hammer2_mtx_unlock(&xop->lock);
 386                 bp->b_flags |= B_NOTMETA;
 387                 chain = xop->head.cluster.focus;
 388                 hammer2_strategy_read_completion(chain, (char *)chain->data,
 389                                                  xop->bio);
 390                 biodone(bio);
 391                 hammer2_xop_retire(&xop->head, HAMMER2_XOPMASK_VOP);
 392                 break;
 393         case HAMMER2_ERROR_ENOENT:
 394                 xop->finished = 1;
 395                 hammer2_mtx_unlock(&xop->lock);
 396                 bp->b_flags |= B_NOTMETA;
 397                 bp->b_resid = 0;
 398                 bp->b_error = 0;
 399                 bzero(bp->b_data, bp->b_bcount);
 400                 biodone(bio);
 401                 hammer2_xop_retire(&xop->head, HAMMER2_XOPMASK_VOP);
 402                 break;
 403         case HAMMER2_ERROR_EINPROGRESS:
 404                 hammer2_mtx_unlock(&xop->lock);
 405                 break;
 406         default:
 407                 kprintf("strategy_xop_read: error %08x loff=%016jx\n",
 408                         error, bp->b_loffset);
 409                 xop->finished = 1;
 410                 hammer2_mtx_unlock(&xop->lock);
 411                 bp->b_flags |= B_ERROR;
 412                 bp->b_error = EIO;
 413                 biodone(bio);
 414                 hammer2_xop_retire(&xop->head, HAMMER2_XOPMASK_VOP);
 415                 break;
 416         }
 417 }
 418
 419 static
 420 void
 421 hammer2_strategy_read_completion(hammer2_chain_t *chain, char *data,
 422                                  struct bio *bio)
 423 {
 424         struct buf *bp = bio->bio_buf;
 425
 426         if (chain->bref.type == HAMMER2_BREF_TYPE_INODE) {
 427                 /*
 428                  * Copy from in-memory inode structure.
 429                  */
 430                 bcopy(((hammer2_inode_data_t *)data)->u.data,
 431                       bp->b_data, HAMMER2_EMBEDDED_BYTES);
 432                 bzero(bp->b_data + HAMMER2_EMBEDDED_BYTES,
 433                       bp->b_bcount - HAMMER2_EMBEDDED_BYTES);
 434                 bp->b_resid = 0;
 435                 bp->b_error = 0;
 436         } else if (chain->bref.type == HAMMER2_BREF_TYPE_DATA) {
 437                 /*
 438                  * Data is on-media, record for live dedup.  Release the
 439                  * chain (try to free it) when done.  The data is still
 440                  * cached by both the buffer cache in front and the
 441                  * block device behind us.  This leaves more room in the
 442                  * LRU chain cache for meta-data chains which we really
 443                  * want to retain.
 444                  *
 445                  * NOTE: Deduplication cannot be safely recorded for
 446                  *       records without a check code.
 447                  */
 448                 hammer2_dedup_record(chain, NULL, data);
 449                 atomic_set_int(&chain->flags, HAMMER2_CHAIN_RELEASE);
 450
 451                 /*
 452                  * Decompression and copy.
 453                  */
 454                 switch (HAMMER2_DEC_COMP(chain->bref.methods)) {
 455                 case HAMMER2_COMP_LZ4:
 456                         hammer2_decompress_LZ4_callback(data, chain->bytes,
 457                                                         bio);
 458                         /* b_resid set by call */
 459                         break;
 460                 case HAMMER2_COMP_ZLIB:
 461                         hammer2_decompress_ZLIB_callback(data, chain->bytes,
 462                                                          bio);
 463                         /* b_resid set by call */
 464                         break;
 465                 case HAMMER2_COMP_NONE:
 466                         KKASSERT(chain->bytes <= bp->b_bcount);
 467                         bcopy(data, bp->b_data, chain->bytes);
 468                         if (chain->bytes < bp->b_bcount) {
 469                                 bzero(bp->b_data + chain->bytes,
 470                                       bp->b_bcount - chain->bytes);
 471                         }
 472                         bp->b_resid = 0;
 473                         bp->b_error = 0;
 474                         break;
 475                 default:
 476                         panic("hammer2_strategy_read: "
 477                               "unknown compression type");
 478                 }
 479         } else {
 480                 panic("hammer2_strategy_read: unknown bref type");
 481         }
 482 }
 483
 484 /****************************************************************************
 485  *                              WRITE SUPPORT                               *
 486  ****************************************************************************/
 487
 488 /*
 489  * Functions for compression in threads,
 490  * from hammer2_vnops.c
 491  */
 492 static void hammer2_write_file_core(char *data, hammer2_inode_t *ip,
 493                                 hammer2_chain_t **parentp,
 494                                 hammer2_key_t lbase, int ioflag, int pblksize,
 495                                 hammer2_tid_t mtid, int *errorp);
 496 static void hammer2_compress_and_write(char *data, hammer2_inode_t *ip,
 497                                 hammer2_chain_t **parentp,
 498                                 hammer2_key_t lbase, int ioflag, int pblksize,
 499                                 hammer2_tid_t mtid, int *errorp,
 500                                 int comp_algo, int check_algo);
 501 static void hammer2_zero_check_and_write(char *data, hammer2_inode_t *ip,
 502                                 hammer2_chain_t **parentp,
 503                                 hammer2_key_t lbase, int ioflag, int pblksize,
 504                                 hammer2_tid_t mtid, int *errorp,
 505                                 int check_algo);
 506 static int test_block_zeros(const char *buf, size_t bytes);
 507 static void zero_write(char *data, hammer2_inode_t *ip,
 508                                 hammer2_chain_t **parentp,
 509                                 hammer2_key_t lbase,
 510                                 hammer2_tid_t mtid, int *errorp);
 511 static void hammer2_write_bp(hammer2_chain_t *chain, char *data,
 512                                 int ioflag, int pblksize,
 513                                 hammer2_tid_t mtid, int *errorp,
 514                                 int check_algo);
 515
 516 static
 517 int
 518 hammer2_strategy_write(struct vop_strategy_args *ap)
 519 {
 520         hammer2_xop_strategy_t *xop;
 521         hammer2_pfs_t *pmp;
 522         struct bio *bio;
 523         struct buf *bp;
 524         hammer2_inode_t *ip;
 525
 526         bio = ap->a_bio;
 527         bp = bio->bio_buf;
 528         ip = VTOI(ap->a_vp);
 529         pmp = ip->pmp;
 530
 531         hammer2_lwinprog_ref(pmp);
 532         hammer2_trans_assert_strategy(pmp);
 533         hammer2_trans_init(pmp, HAMMER2_TRANS_BUFCACHE);
 534
 535         xop = hammer2_xop_alloc(ip, HAMMER2_XOP_MODIFYING |
 536                                     HAMMER2_XOP_STRATEGY);
 537         xop->finished = 0;
 538         xop->bio = bio;
 539         xop->lbase = bio->bio_offset;
 540         hammer2_mtx_init(&xop->lock, "h2biow");
 541         hammer2_xop_start(&xop->head, hammer2_strategy_xop_write);
 542         /* asynchronous completion */
 543
 544         hammer2_lwinprog_wait(pmp, hammer2_flush_pipe);
 545
 546         return(0);
 547 }
 548
 549 /*
 550  * Per-node XOP (threaded).  Write the logical buffer to the media.
 551  *
 552  * This is a bit problematic because there may be multiple target and
 553  * any of them may be able to release the bp.  In addition, if our
 554  * particulr target is offline we don't want to block the bp (and thus
 555  * the frontend).  To accomplish this we copy the data to the per-thr
 556  * scratch buffer.
 557  */
 558 static
 559 void
 560 hammer2_strategy_xop_write(hammer2_thread_t *thr, hammer2_xop_t *arg)
 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         hammer2_off_t bio_offset;
 572         char *bio_data;
 573
 574         /*
 575          * We can only access the bp/bio if the frontend has not yet
 576          * completed.
 577          */
 578         if (xop->finished)
 579                 return;
 580         hammer2_mtx_sh(&xop->lock);
 581         if (xop->finished) {
 582                 hammer2_mtx_unlock(&xop->lock);
 583                 return;
 584         }
 585
 586         lbase = xop->lbase;
 587         bio = xop->bio;                 /* ephermal */
 588         bp = bio->bio_buf;              /* ephermal */
 589         ip = xop->head.ip1;             /* retained by ref */
 590         bio_offset = bio->bio_offset;
 591         bio_data = thr->scratch;
 592
 593         /* hammer2_trans_init(parent->hmp->spmp, HAMMER2_TRANS_BUFCACHE); */
 594
 595         lblksize = hammer2_calc_logical(ip, bio->bio_offset, &lbase, NULL);
 596         pblksize = hammer2_calc_physical(ip, lbase);
 597         bkvasync(bp);
 598         bcopy(bp->b_data, bio_data, lblksize);
 599
 600         hammer2_mtx_unlock(&xop->lock);
 601         bp = NULL;      /* safety, illegal to access after unlock */
 602         bio = NULL;     /* safety, illegal to access after unlock */
 603
 604         /*
 605          * Actual operation
 606          */
 607         parent = hammer2_inode_chain(ip, thr->clindex, HAMMER2_RESOLVE_ALWAYS);
 608         hammer2_write_file_core(bio_data, ip, &parent,
 609                                 lbase, IO_ASYNC, pblksize,
 610                                 xop->head.mtid, &error);
 611         if (parent) {
 612                 hammer2_chain_unlock(parent);
 613                 hammer2_chain_drop(parent);
 614                 parent = NULL;  /* safety */
 615         }
 616         hammer2_xop_feed(&xop->head, NULL, thr->clindex, error);
 617
 618         /*
 619          * Try to complete the operation on behalf of the front-end.
 620          */
 621         if (xop->finished)
 622                 return;
 623         hammer2_mtx_ex(&xop->lock);
 624         if (xop->finished) {
 625                 hammer2_mtx_unlock(&xop->lock);
 626                 return;
 627         }
 628
 629         /*
 630          * Async operation has not completed and we now own the lock.
 631          * Determine if we can complete the operation by issuing the
 632          * frontend collection non-blocking.
 633          *
 634          * H2 double-buffers the data, setting B_NOTMETA on the logical
 635          * buffer hints to the OS that the logical buffer should not be
 636          * swapcached (since the device buffer can be).
 637          */
 638         error = hammer2_xop_collect(&xop->head, HAMMER2_XOP_COLLECT_NOWAIT);
 639
 640         if (error == HAMMER2_ERROR_EINPROGRESS) {
 641                 hammer2_mtx_unlock(&xop->lock);
 642                 return;
 643         }
 644
 645         /*
 646          * Async operation has completed.
 647          */
 648         xop->finished = 1;
 649         hammer2_mtx_unlock(&xop->lock);
 650
 651         bio = xop->bio;         /* now owned by us */
 652         bp = bio->bio_buf;      /* now owned by us */
 653
 654         if (error == HAMMER2_ERROR_ENOENT || error == 0) {
 655                 bp->b_flags |= B_NOTMETA;
 656                 bp->b_resid = 0;
 657                 bp->b_error = 0;
 658                 biodone(bio);
 659         } else {
 660                 kprintf("strategy_xop_write: error %d loff=%016jx\n",
 661                         error, bp->b_loffset);
 662                 bp->b_flags |= B_ERROR;
 663                 bp->b_error = EIO;
 664                 biodone(bio);
 665         }
 666         hammer2_xop_retire(&xop->head, HAMMER2_XOPMASK_VOP);
 667         hammer2_trans_assert_strategy(ip->pmp);
 668         hammer2_lwinprog_drop(ip->pmp);
 669         hammer2_trans_done(ip->pmp);
 670 }
 671
 672 /*
 673  * Wait for pending I/O to complete
 674  */
 675 void
 676 hammer2_bioq_sync(hammer2_pfs_t *pmp)
 677 {
 678         hammer2_lwinprog_wait(pmp, 0);
 679 }
 680
 681 /*
 682  * Assign physical storage at (cparent, lbase), returning a suitable chain
 683  * and setting *errorp appropriately.
 684  *
 685  * If no error occurs, the returned chain will be in a modified state.
 686  *
 687  * If an error occurs, the returned chain may or may not be NULL.  If
 688  * not-null any chain->error (if not 0) will also be rolled up into *errorp.
 689  * So the caller only needs to test *errorp.
 690  *
 691  * cparent can wind up being anything.
 692  *
 693  * If datap is not NULL, *datap points to the real data we intend to write.
 694  * If we can dedup the storage location we set *datap to NULL to indicate
 695  * to the caller that a dedup occurred.
 696  *
 697  * NOTE: Special case for data embedded in inode.
 698  */
 699 static
 700 hammer2_chain_t *
 701 hammer2_assign_physical(hammer2_inode_t *ip, hammer2_chain_t **parentp,
 702                         hammer2_key_t lbase, int pblksize,
 703                         hammer2_tid_t mtid, char **datap, int *errorp)
 704 {
 705         hammer2_chain_t *chain;
 706         hammer2_key_t key_dummy;
 707         hammer2_off_t dedup_off;
 708         int pradix = hammer2_getradix(pblksize);
 709
 710         /*
 711          * Locate the chain associated with lbase, return a locked chain.
 712          * However, do not instantiate any data reference (which utilizes a
 713          * device buffer) because we will be using direct IO via the
 714          * logical buffer cache buffer.
 715          */
 716         KKASSERT(pblksize >= HAMMER2_ALLOC_MIN);
 717
 718         chain = hammer2_chain_lookup(parentp, &key_dummy,
 719                                      lbase, lbase,
 720                                      errorp,
 721                                      HAMMER2_LOOKUP_NODATA);
 722
 723         /*
 724          * The lookup code should not return a DELETED chain to us, unless
 725          * its a short-file embedded in the inode.  Then it is possible for
 726          * the lookup to return a deleted inode.
 727          */
 728         if (chain && (chain->flags & HAMMER2_CHAIN_DELETED) &&
 729             chain->bref.type != HAMMER2_BREF_TYPE_INODE) {
 730                 kprintf("assign physical deleted chain @ "
 731                         "%016jx (%016jx.%02x) ip %016jx\n",
 732                         lbase, chain->bref.data_off, chain->bref.type,
 733                         ip->meta.inum);
 734                 Debugger("bleh");
 735         }
 736
 737         if (chain == NULL) {
 738                 /*
 739                  * We found a hole, create a new chain entry.
 740                  *
 741                  * NOTE: DATA chains are created without device backing
 742                  *       store (nor do we want any).
 743                  */
 744                 dedup_off = hammer2_dedup_lookup((*parentp)->hmp, datap,
 745                                                  pblksize);
 746                 *errorp |= hammer2_chain_create(parentp, &chain,
 747                                                 ip->pmp,
 748                                        HAMMER2_ENC_CHECK(ip->meta.check_algo) |
 749                                        HAMMER2_ENC_COMP(HAMMER2_COMP_NONE),
 750                                                 lbase, HAMMER2_PBUFRADIX,
 751                                                 HAMMER2_BREF_TYPE_DATA,
 752                                                 pblksize, mtid,
 753                                                 dedup_off, 0);
 754                 if (chain == NULL)
 755                         goto failed;
 756                 /*ip->delta_dcount += pblksize;*/
 757         } else if (chain->error == 0) {
 758                 switch (chain->bref.type) {
 759                 case HAMMER2_BREF_TYPE_INODE:
 760                         /*
 761                          * The data is embedded in the inode, which requires
 762                          * a bit more finess.
 763                          */
 764                         *errorp |= hammer2_chain_modify_ip(ip, chain, mtid, 0);
 765                         break;
 766                 case HAMMER2_BREF_TYPE_DATA:
 767                         dedup_off = hammer2_dedup_lookup(chain->hmp, datap,
 768                                                          pblksize);
 769                         if (chain->bytes != pblksize) {
 770                                 *errorp |= hammer2_chain_resize(chain,
 771                                                      mtid, dedup_off,
 772                                                      pradix,
 773                                                      HAMMER2_MODIFY_OPTDATA);
 774                                 if (*errorp)
 775                                         break;
 776                         }
 777
 778                         /*
 779                          * DATA buffers must be marked modified whether the
 780                          * data is in a logical buffer or not.  We also have
 781                          * to make this call to fixup the chain data pointers
 782                          * after resizing in case this is an encrypted or
 783                          * compressed buffer.
 784                          */
 785                         *errorp |= hammer2_chain_modify(chain, mtid, dedup_off,
 786                                                         HAMMER2_MODIFY_OPTDATA);
 787                         break;
 788                 default:
 789                         panic("hammer2_assign_physical: bad type");
 790                         /* NOT REACHED */
 791                         break;
 792                 }
 793         } else {
 794                 *errorp = chain->error;
 795         }
 796 failed:
 797         return (chain);
 798 }
 799
 800 /*
 801  * hammer2_write_file_core() - hammer2_write_thread() helper
 802  *
 803  * The core write function which determines which path to take
 804  * depending on compression settings.  We also have to locate the
 805  * related chains so we can calculate and set the check data for
 806  * the blockref.
 807  */
 808 static
 809 void
 810 hammer2_write_file_core(char *data, hammer2_inode_t *ip,
 811                         hammer2_chain_t **parentp,
 812                         hammer2_key_t lbase, int ioflag, int pblksize,
 813                         hammer2_tid_t mtid, int *errorp)
 814 {
 815         hammer2_chain_t *chain;
 816         char *bdata;
 817
 818         *errorp = 0;
 819
 820         switch(HAMMER2_DEC_ALGO(ip->meta.comp_algo)) {
 821         case HAMMER2_COMP_NONE:
 822                 /*
 823                  * We have to assign physical storage to the buffer
 824                  * we intend to dirty or write now to avoid deadlocks
 825                  * in the strategy code later.
 826                  *
 827                  * This can return NOOFFSET for inode-embedded data.
 828                  * The strategy code will take care of it in that case.
 829                  */
 830                 bdata = data;
 831                 chain = hammer2_assign_physical(ip, parentp, lbase, pblksize,
 832                                                 mtid, &bdata, errorp);
 833                 if (*errorp) {
 834                         /* skip modifications */
 835                 } else if (chain->bref.type == HAMMER2_BREF_TYPE_INODE) {
 836                         hammer2_inode_data_t *wipdata;
 837
 838                         wipdata = &chain->data->ipdata;
 839                         KKASSERT(wipdata->meta.op_flags &
 840                                  HAMMER2_OPFLAG_DIRECTDATA);
 841                         bcopy(data, wipdata->u.data, HAMMER2_EMBEDDED_BYTES);
 842                         ++hammer2_iod_file_wembed;
 843                 } else if (bdata == NULL) {
 844                         /*
 845                          * Copy of data already present on-media.
 846                          */
 847                         chain->bref.methods =
 848                                 HAMMER2_ENC_COMP(HAMMER2_COMP_NONE) +
 849                                 HAMMER2_ENC_CHECK(ip->meta.check_algo);
 850                         hammer2_chain_setcheck(chain, data);
 851                 } else {
 852                         hammer2_write_bp(chain, data, ioflag, pblksize,
 853                                          mtid, errorp, ip->meta.check_algo);
 854                 }
 855                 if (chain) {
 856                         hammer2_chain_unlock(chain);
 857                         hammer2_chain_drop(chain);
 858                 }
 859                 break;
 860         case HAMMER2_COMP_AUTOZERO:
 861                 /*
 862                  * Check for zero-fill only
 863                  */
 864                 hammer2_zero_check_and_write(data, ip, parentp,
 865                                              lbase, ioflag, pblksize,
 866                                              mtid, errorp,
 867                                              ip->meta.check_algo);
 868                 break;
 869         case HAMMER2_COMP_LZ4:
 870         case HAMMER2_COMP_ZLIB:
 871         default:
 872                 /*
 873                  * Check for zero-fill and attempt compression.
 874                  */
 875                 hammer2_compress_and_write(data, ip, parentp,
 876                                            lbase, ioflag, pblksize,
 877                                            mtid, errorp,
 878                                            ip->meta.comp_algo,
 879                                            ip->meta.check_algo);
 880                 break;
 881         }
 882 }
 883
 884 /*
 885  * Helper
 886  *
 887  * Generic function that will perform the compression in compression
 888  * write path. The compression algorithm is determined by the settings
 889  * obtained from inode.
 890  */
 891 static
 892 void
 893 hammer2_compress_and_write(char *data, hammer2_inode_t *ip,
 894         hammer2_chain_t **parentp,
 895         hammer2_key_t lbase, int ioflag, int pblksize,
 896         hammer2_tid_t mtid, int *errorp, int comp_algo, int check_algo)
 897 {
 898         hammer2_chain_t *chain;
 899         int comp_size;
 900         int comp_block_size;
 901         char *comp_buffer;
 902         char *bdata;
 903
 904         /*
 905          * An all-zeros write creates a hole unless the check code
 906          * is disabled.  When the check code is disabled all writes
 907          * are done in-place, including any all-zeros writes.
 908          *
 909          * NOTE: A snapshot will still force a copy-on-write
 910          *       (see the HAMMER2_CHECK_NONE in hammer2_chain.c).
 911          */
 912         if (check_algo != HAMMER2_CHECK_NONE &&
 913             test_block_zeros(data, pblksize)) {
 914                 zero_write(data, ip, parentp, lbase, mtid, errorp);
 915                 return;
 916         }
 917
 918         /*
 919          * Compression requested.  Try to compress the block.  We store
 920          * the data normally if we cannot sufficiently compress it.
 921          *
 922          * We have a heuristic to detect files which are mostly
 923          * uncompressable and avoid the compression attempt in that
 924          * case.  If the compression heuristic is turned off, we always
 925          * try to compress.
 926          */
 927         comp_size = 0;
 928         comp_buffer = NULL;
 929
 930         KKASSERT(pblksize / 2 <= 32768);
 931
 932         if (ip->comp_heuristic < 8 || (ip->comp_heuristic & 7) == 0 ||
 933             hammer2_always_compress) {
 934                 z_stream strm_compress;
 935                 int comp_level;
 936                 int ret;
 937
 938                 switch(HAMMER2_DEC_ALGO(comp_algo)) {
 939                 case HAMMER2_COMP_LZ4:
 940                         /*
 941                          * We need to prefix with the size, LZ4
 942                          * doesn't do it for us.  Add the related
 943                          * overhead.
 944                          *
 945                          * NOTE: The LZ4 code seems to assume at least an
 946                          *       8-byte buffer size granularity and may
 947                          *       overrun the buffer if given a 4-byte
 948                          *       granularity.
 949                          */
 950                         comp_buffer = objcache_get(cache_buffer_write,
 951                                                    M_INTWAIT);
 952                         comp_size = LZ4_compress_limitedOutput(
 953                                         data,
 954                                         &comp_buffer[sizeof(int)],
 955                                         pblksize,
 956                                         pblksize / 2 - sizeof(int64_t));
 957                         *(int *)comp_buffer = comp_size;
 958                         if (comp_size)
 959                                 comp_size += sizeof(int);
 960                         break;
 961                 case HAMMER2_COMP_ZLIB:
 962                         comp_level = HAMMER2_DEC_LEVEL(comp_algo);
 963                         if (comp_level == 0)
 964                                 comp_level = 6; /* default zlib compression */
 965                         else if (comp_level < 6)
 966                                 comp_level = 6;
 967                         else if (comp_level > 9)
 968                                 comp_level = 9;
 969                         ret = deflateInit(&strm_compress, comp_level);
 970                         if (ret != Z_OK) {
 971                                 kprintf("HAMMER2 ZLIB: fatal error "
 972                                         "on deflateInit.\n");
 973                         }
 974
 975                         comp_buffer = objcache_get(cache_buffer_write,
 976                                                    M_INTWAIT);
 977                         strm_compress.next_in = data;
 978                         strm_compress.avail_in = pblksize;
 979                         strm_compress.next_out = comp_buffer;
 980                         strm_compress.avail_out = pblksize / 2;
 981                         ret = deflate(&strm_compress, Z_FINISH);
 982                         if (ret == Z_STREAM_END) {
 983                                 comp_size = pblksize / 2 -
 984                                             strm_compress.avail_out;
 985                         } else {
 986                                 comp_size = 0;
 987                         }
 988                         ret = deflateEnd(&strm_compress);
 989                         break;
 990                 default:
 991                         kprintf("Error: Unknown compression method.\n");
 992                         kprintf("Comp_method = %d.\n", comp_algo);
 993                         break;
 994                 }
 995         }
 996
 997         if (comp_size == 0) {
 998                 /*
 999                  * compression failed or turned off
1000                  */
1001                 comp_block_size = pblksize;     /* safety */
1002                 if (++ip->comp_heuristic > 128)
1003                         ip->comp_heuristic = 8;
1004         } else {
1005                 /*
1006                  * compression succeeded
1007                  */
1008                 ip->comp_heuristic = 0;
1009                 if (comp_size <= 1024) {
1010                         comp_block_size = 1024;
1011                 } else if (comp_size <= 2048) {
1012                         comp_block_size = 2048;
1013                 } else if (comp_size <= 4096) {
1014                         comp_block_size = 4096;
1015                 } else if (comp_size <= 8192) {
1016                         comp_block_size = 8192;
1017                 } else if (comp_size <= 16384) {
1018                         comp_block_size = 16384;
1019                 } else if (comp_size <= 32768) {
1020                         comp_block_size = 32768;
1021                 } else {
1022                         panic("hammer2: WRITE PATH: "
1023                               "Weird comp_size value.");
1024                         /* NOT REACHED */
1025                         comp_block_size = pblksize;
1026                 }
1027
1028                 /*
1029                  * Must zero the remainder or dedup (which operates on a
1030                  * physical block basis) will not find matches.
1031                  */
1032                 if (comp_size < comp_block_size) {
1033                         bzero(comp_buffer + comp_size,
1034                               comp_block_size - comp_size);
1035                 }
1036         }
1037
1038         /*
1039          * Assign physical storage, data will be set to NULL if a live-dedup
1040          * was successful.
1041          */
1042         bdata = comp_size ? comp_buffer : data;
1043         chain = hammer2_assign_physical(ip, parentp, lbase, comp_block_size,
1044                                         mtid, &bdata, errorp);
1045
1046         if (*errorp) {
1047                 goto done;
1048         }
1049
1050         if (chain->bref.type == HAMMER2_BREF_TYPE_INODE) {
1051                 hammer2_inode_data_t *wipdata;
1052
1053                 *errorp = hammer2_chain_modify_ip(ip, chain, mtid, 0);
1054                 if (*errorp == 0) {
1055                         wipdata = &chain->data->ipdata;
1056                         KKASSERT(wipdata->meta.op_flags &
1057                                  HAMMER2_OPFLAG_DIRECTDATA);
1058                         bcopy(data, wipdata->u.data, HAMMER2_EMBEDDED_BYTES);
1059                         ++hammer2_iod_file_wembed;
1060                 }
1061         } else if (bdata == NULL) {
1062                 /*
1063                  * Live deduplication, a copy of the data is already present
1064                  * on the media.
1065                  */
1066                 if (comp_size) {
1067                         chain->bref.methods =
1068                                 HAMMER2_ENC_COMP(comp_algo) +
1069                                 HAMMER2_ENC_CHECK(check_algo);
1070                 } else {
1071                         chain->bref.methods =
1072                                 HAMMER2_ENC_COMP(
1073                                         HAMMER2_COMP_NONE) +
1074                                 HAMMER2_ENC_CHECK(check_algo);
1075                 }
1076                 bdata = comp_size ? comp_buffer : data;
1077                 hammer2_chain_setcheck(chain, bdata);
1078                 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_INITIAL);
1079         } else {
1080                 hammer2_io_t *dio;
1081
1082                 KKASSERT(chain->flags & HAMMER2_CHAIN_MODIFIED);
1083
1084                 switch(chain->bref.type) {
1085                 case HAMMER2_BREF_TYPE_INODE:
1086                         panic("hammer2_write_bp: unexpected inode\n");
1087                         break;
1088                 case HAMMER2_BREF_TYPE_DATA:
1089                         /*
1090                          * Optimize out the read-before-write
1091                          * if possible.
1092                          */
1093                         *errorp = hammer2_io_newnz(chain->hmp,
1094                                                    chain->bref.type,
1095                                                    chain->bref.data_off,
1096                                                    chain->bytes,
1097                                                    &dio);
1098                         if (*errorp) {
1099                                 hammer2_io_brelse(&dio);
1100                                 kprintf("hammer2: WRITE PATH: "
1101                                         "dbp bread error\n");
1102                                 break;
1103                         }
1104                         bdata = hammer2_io_data(dio, chain->bref.data_off);
1105
1106                         /*
1107                          * When loading the block make sure we don't
1108                          * leave garbage after the compressed data.
1109                          */
1110                         if (comp_size) {
1111                                 chain->bref.methods =
1112                                         HAMMER2_ENC_COMP(comp_algo) +
1113                                         HAMMER2_ENC_CHECK(check_algo);
1114                                 bcopy(comp_buffer, bdata, comp_size);
1115                         } else {
1116                                 chain->bref.methods =
1117                                         HAMMER2_ENC_COMP(
1118                                                 HAMMER2_COMP_NONE) +
1119                                         HAMMER2_ENC_CHECK(check_algo);
1120                                 bcopy(data, bdata, pblksize);
1121                         }
1122
1123                         /*
1124                          * The flush code doesn't calculate check codes for
1125                          * file data (doing so can result in excessive I/O),
1126                          * so we do it here.
1127                          */
1128                         hammer2_chain_setcheck(chain, bdata);
1129
1130                         /*
1131                          * Device buffer is now valid, chain is no longer in
1132                          * the initial state.
1133                          *
1134                          * (No blockref table worries with file data)
1135                          */
1136                         atomic_clear_int(&chain->flags, HAMMER2_CHAIN_INITIAL);
1137                         hammer2_dedup_record(chain, dio, bdata);
1138
1139                         /* Now write the related bdp. */
1140                         if (ioflag & IO_SYNC) {
1141                                 /*
1142                                  * Synchronous I/O requested.
1143                                  */
1144                                 hammer2_io_bwrite(&dio);
1145                         /*
1146                         } else if ((ioflag & IO_DIRECT) &&
1147                                    loff + n == pblksize) {
1148                                 hammer2_io_bdwrite(&dio);
1149                         */
1150                         } else if (ioflag & IO_ASYNC) {
1151                                 hammer2_io_bawrite(&dio);
1152                         } else {
1153                                 hammer2_io_bdwrite(&dio);
1154                         }
1155                         break;
1156                 default:
1157                         panic("hammer2_write_bp: bad chain type %d\n",
1158                                 chain->bref.type);
1159                         /* NOT REACHED */
1160                         break;
1161                 }
1162         }
1163 done:
1164         if (chain) {
1165                 hammer2_chain_unlock(chain);
1166                 hammer2_chain_drop(chain);
1167         }
1168         if (comp_buffer)
1169                 objcache_put(cache_buffer_write, comp_buffer);
1170 }
1171
1172 /*
1173  * Helper
1174  *
1175  * Function that performs zero-checking and writing without compression,
1176  * it corresponds to default zero-checking path.
1177  */
1178 static
1179 void
1180 hammer2_zero_check_and_write(char *data, hammer2_inode_t *ip,
1181         hammer2_chain_t **parentp,
1182         hammer2_key_t lbase, int ioflag, int pblksize,
1183         hammer2_tid_t mtid, int *errorp,
1184         int check_algo)
1185 {
1186         hammer2_chain_t *chain;
1187         char *bdata;
1188
1189         if (check_algo != HAMMER2_CHECK_NONE &&
1190             test_block_zeros(data, pblksize)) {
1191                 /*
1192                  * An all-zeros write creates a hole unless the check code
1193                  * is disabled.  When the check code is disabled all writes
1194                  * are done in-place, including any all-zeros writes.
1195                  *
1196                  * NOTE: A snapshot will still force a copy-on-write
1197                  *       (see the HAMMER2_CHECK_NONE in hammer2_chain.c).
1198                  */
1199                 zero_write(data, ip, parentp, lbase, mtid, errorp);
1200         } else {
1201                 /*
1202                  * Normal write
1203                  */
1204                 bdata = data;
1205                 chain = hammer2_assign_physical(ip, parentp, lbase, pblksize,
1206                                                 mtid, &bdata, errorp);
1207                 if (*errorp) {
1208                         /* do nothing */
1209                 } else if (bdata) {
1210                         hammer2_write_bp(chain, data, ioflag, pblksize,
1211                                          mtid, errorp, check_algo);
1212                 } else {
1213                         /* dedup occurred */
1214                         chain->bref.methods =
1215                                 HAMMER2_ENC_COMP(HAMMER2_COMP_NONE) +
1216                                 HAMMER2_ENC_CHECK(check_algo);
1217                         hammer2_chain_setcheck(chain, data);
1218                 }
1219                 if (chain) {
1220                         hammer2_chain_unlock(chain);
1221                         hammer2_chain_drop(chain);
1222                 }
1223         }
1224 }
1225
1226 /*
1227  * Helper
1228  *
1229  * A function to test whether a block of data contains only zeros,
1230  * returns TRUE (non-zero) if the block is all zeros.
1231  */
1232 static
1233 int
1234 test_block_zeros(const char *buf, size_t bytes)
1235 {
1236         size_t i;
1237
1238         for (i = 0; i < bytes; i += sizeof(long)) {
1239                 if (*(const long *)(buf + i) != 0)
1240                         return (0);
1241         }
1242         return (1);
1243 }
1244
1245 /*
1246  * Helper
1247  *
1248  * Function to "write" a block that contains only zeros.
1249  */
1250 static
1251 void
1252 zero_write(char *data, hammer2_inode_t *ip,
1253            hammer2_chain_t **parentp,
1254            hammer2_key_t lbase, hammer2_tid_t mtid, int *errorp)
1255 {
1256         hammer2_chain_t *chain;
1257         hammer2_key_t key_dummy;
1258
1259         chain = hammer2_chain_lookup(parentp, &key_dummy,
1260                                      lbase, lbase,
1261                                      errorp,
1262                                      HAMMER2_LOOKUP_NODATA);
1263         if (chain) {
1264                 if (chain->bref.type == HAMMER2_BREF_TYPE_INODE) {
1265                         hammer2_inode_data_t *wipdata;
1266
1267                         if (*errorp == 0) {
1268                                 *errorp = hammer2_chain_modify_ip(ip, chain,
1269                                                                   mtid, 0);
1270                         }
1271                         if (*errorp == 0) {
1272                                 wipdata = &chain->data->ipdata;
1273                                 KKASSERT(wipdata->meta.op_flags &
1274                                          HAMMER2_OPFLAG_DIRECTDATA);
1275                                 bzero(wipdata->u.data, HAMMER2_EMBEDDED_BYTES);
1276                                 ++hammer2_iod_file_wembed;
1277                         }
1278                 } else {
1279                         /* chain->error ok for deletion */
1280                         hammer2_chain_delete(*parentp, chain,
1281                                              mtid, HAMMER2_DELETE_PERMANENT);
1282                         ++hammer2_iod_file_wzero;
1283                 }
1284                 hammer2_chain_unlock(chain);
1285                 hammer2_chain_drop(chain);
1286         } else {
1287                 ++hammer2_iod_file_wzero;
1288         }
1289 }
1290
1291 /*
1292  * Helper
1293  *
1294  * Function to write the data as it is, without performing any sort of
1295  * compression. This function is used in path without compression and
1296  * default zero-checking path.
1297  */
1298 static
1299 void
1300 hammer2_write_bp(hammer2_chain_t *chain, char *data, int ioflag,
1301                  int pblksize,
1302                  hammer2_tid_t mtid, int *errorp, int check_algo)
1303 {
1304         hammer2_inode_data_t *wipdata;
1305         hammer2_io_t *dio;
1306         char *bdata;
1307         int error;
1308
1309         error = 0;      /* XXX TODO below */
1310
1311         KKASSERT(chain->flags & HAMMER2_CHAIN_MODIFIED);
1312
1313         switch(chain->bref.type) {
1314         case HAMMER2_BREF_TYPE_INODE:
1315                 wipdata = &chain->data->ipdata;
1316                 KKASSERT(wipdata->meta.op_flags & HAMMER2_OPFLAG_DIRECTDATA);
1317                 bcopy(data, wipdata->u.data, HAMMER2_EMBEDDED_BYTES);
1318                 error = 0;
1319                 ++hammer2_iod_file_wembed;
1320                 break;
1321         case HAMMER2_BREF_TYPE_DATA:
1322                 error = hammer2_io_newnz(chain->hmp,
1323                                          chain->bref.type,
1324                                          chain->bref.data_off,
1325                                          chain->bytes, &dio);
1326                 if (error) {
1327                         hammer2_io_bqrelse(&dio);
1328                         kprintf("hammer2: WRITE PATH: "
1329                                 "dbp bread error\n");
1330                         break;
1331                 }
1332                 bdata = hammer2_io_data(dio, chain->bref.data_off);
1333
1334                 chain->bref.methods = HAMMER2_ENC_COMP(HAMMER2_COMP_NONE) +
1335                                       HAMMER2_ENC_CHECK(check_algo);
1336                 bcopy(data, bdata, chain->bytes);
1337
1338                 /*
1339                  * The flush code doesn't calculate check codes for
1340                  * file data (doing so can result in excessive I/O),
1341                  * so we do it here.
1342                  */
1343                 hammer2_chain_setcheck(chain, bdata);
1344
1345                 /*
1346                  * Device buffer is now valid, chain is no longer in
1347                  * the initial state.
1348                  *
1349                  * (No blockref table worries with file data)
1350                  */
1351                 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_INITIAL);
1352                 hammer2_dedup_record(chain, dio, bdata);
1353
1354                 if (ioflag & IO_SYNC) {
1355                         /*
1356                          * Synchronous I/O requested.
1357                          */
1358                         hammer2_io_bwrite(&dio);
1359                 /*
1360                 } else if ((ioflag & IO_DIRECT) &&
1361                            loff + n == pblksize) {
1362                         hammer2_io_bdwrite(&dio);
1363                 */
1364                 } else if (ioflag & IO_ASYNC) {
1365                         hammer2_io_bawrite(&dio);
1366                 } else {
1367                         hammer2_io_bdwrite(&dio);
1368                 }
1369                 break;
1370         default:
1371                 panic("hammer2_write_bp: bad chain type %d\n",
1372                       chain->bref.type);
1373                 /* NOT REACHED */
1374                 error = 0;
1375                 break;
1376         }
1377         *errorp = error;
1378 }
1379
1380 /*
1381  * LIVE DEDUP HEURISTICS
1382  *
1383  * Record media and crc information for possible dedup operation.  Note
1384  * that the dedup mask bits must also be set in the related DIO for a dedup
1385  * to be fully validated (which is handled in the freemap allocation code).
1386  *
1387  * WARNING! This code is SMP safe but the heuristic allows SMP collisions.
1388  *          All fields must be loaded into locals and validated.
1389  *
1390  * WARNING! Should only be used for file data and directory entries,
1391  *          hammer2_chain_modify() only checks for the dedup case on data
1392  *          chains.  Also, dedup data can only be recorded for committed
1393  *          chains (so NOT strategy writes which can undergo further
1394  *          modification after the fact!).
1395  */
1396 void
1397 hammer2_dedup_record(hammer2_chain_t *chain, hammer2_io_t *dio, char *data)
1398 {
1399         hammer2_dev_t *hmp;
1400         hammer2_dedup_t *dedup;
1401         uint64_t crc;
1402         uint64_t mask;
1403         int best = 0;
1404         int i;
1405         int dticks;
1406
1407         /*
1408          * We can only record a dedup if we have media data to test against.
1409          * If dedup is not enabled, return early, which allows a chain to
1410          * remain marked MODIFIED (which might have benefits in special
1411          * situations, though typically it does not).
1412          */
1413         if (hammer2_dedup_enable == 0)
1414                 return;
1415         if (dio == NULL) {
1416                 dio = chain->dio;
1417                 if (dio == NULL)
1418                         return;
1419         }
1420
1421         hmp = chain->hmp;
1422
1423         switch(HAMMER2_DEC_CHECK(chain->bref.methods)) {
1424         case HAMMER2_CHECK_ISCSI32:
1425                 /*
1426                  * XXX use the built-in crc (the dedup lookup sequencing
1427                  * needs to be fixed so the check code is already present
1428                  * when dedup_lookup is called)
1429                  */
1430 #if 0
1431                 crc = (uint64_t)(uint32_t)chain->bref.check.iscsi32.value;
1432 #endif
1433                 crc = XXH64(data, chain->bytes, XXH_HAMMER2_SEED);
1434                 break;
1435         case HAMMER2_CHECK_XXHASH64:
1436                 crc = chain->bref.check.xxhash64.value;
1437                 break;
1438         case HAMMER2_CHECK_SHA192:
1439                 /*
1440                  * XXX use the built-in crc (the dedup lookup sequencing
1441                  * needs to be fixed so the check code is already present
1442                  * when dedup_lookup is called)
1443                  */
1444 #if 0
1445                 crc = ((uint64_t *)chain->bref.check.sha192.data)[0] ^
1446                       ((uint64_t *)chain->bref.check.sha192.data)[1] ^
1447                       ((uint64_t *)chain->bref.check.sha192.data)[2];
1448 #endif
1449                 crc = XXH64(data, chain->bytes, XXH_HAMMER2_SEED);
1450                 break;
1451         default:
1452                 /*
1453                  * Cannot dedup without a check code
1454                  *
1455                  * NOTE: In particular, CHECK_NONE allows a sector to be
1456                  *       overwritten without copy-on-write, recording
1457                  *       a dedup block for a CHECK_NONE object would be
1458                  *       a disaster!
1459                  */
1460                 return;
1461         }
1462
1463         atomic_set_int(&chain->flags, HAMMER2_CHAIN_DEDUPABLE);
1464
1465         dedup = &hmp->heur_dedup[crc & (HAMMER2_DEDUP_HEUR_MASK & ~3)];
1466         for (i = 0; i < 4; ++i) {
1467                 if (dedup[i].data_crc == crc) {
1468                         best = i;
1469                         break;
1470                 }
1471                 dticks = (int)(dedup[i].ticks - dedup[best].ticks);
1472                 if (dticks < 0 || dticks > hz * 60 * 30)
1473                         best = i;
1474         }
1475         dedup += best;
1476         if (hammer2_debug & 0x40000) {
1477                 kprintf("REC %04x %016jx %016jx\n",
1478                         (int)(dedup - hmp->heur_dedup),
1479                         crc,
1480                         chain->bref.data_off);
1481         }
1482         dedup->ticks = ticks;
1483         dedup->data_off = chain->bref.data_off;
1484         dedup->data_crc = crc;
1485
1486         /*
1487          * Set the valid bits for the dedup only after we know the data
1488          * buffer has been updated.  The alloc bits were set (and the valid
1489          * bits cleared) when the media was allocated.
1490          *
1491          * This is done in two stages becuase the bulkfree code can race
1492          * the gap between allocation and data population.  Both masks must
1493          * be set before a bcmp/dedup operation is able to use the block.
1494          */
1495         mask = hammer2_dedup_mask(dio, chain->bref.data_off, chain->bytes);
1496         atomic_set_64(&dio->dedup_valid, mask);
1497
1498 #if 0
1499         /*
1500          * XXX removed. MODIFIED is an integral part of the flush code,
1501          * lets not just clear it
1502          */
1503         /*
1504          * Once we record the dedup the chain must be marked clean to
1505          * prevent reuse of the underlying block.   Remember that this
1506          * write occurs when the buffer cache is flushed (i.e. on sync(),
1507          * fsync(), filesystem periodic sync, or when the kernel needs to
1508          * flush a buffer), and not whenever the user write()s.
1509          */
1510         if (chain->flags & HAMMER2_CHAIN_MODIFIED) {
1511                 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_MODIFIED);
1512                 atomic_add_long(&hammer2_count_modified_chains, -1);
1513                 if (chain->pmp)
1514                         hammer2_pfs_memory_wakeup(chain->pmp);
1515         }
1516 #endif
1517 }
1518
1519 static
1520 hammer2_off_t
1521 hammer2_dedup_lookup(hammer2_dev_t *hmp, char **datap, int pblksize)
1522 {
1523         hammer2_dedup_t *dedup;
1524         hammer2_io_t *dio;
1525         hammer2_off_t off;
1526         uint64_t crc;
1527         uint64_t mask;
1528         char *data;
1529         char *dtmp;
1530         int i;
1531
1532         if (hammer2_dedup_enable == 0)
1533                 return 0;
1534         data = *datap;
1535         if (data == NULL)
1536                 return 0;
1537
1538         /*
1539          * XXX use the built-in crc (the dedup lookup sequencing
1540          * needs to be fixed so the check code is already present
1541          * when dedup_lookup is called)
1542          */
1543         crc = XXH64(data, pblksize, XXH_HAMMER2_SEED);
1544         dedup = &hmp->heur_dedup[crc & (HAMMER2_DEDUP_HEUR_MASK & ~3)];
1545
1546         if (hammer2_debug & 0x40000) {
1547                 kprintf("LOC %04x/4 %016jx\n",
1548                         (int)(dedup - hmp->heur_dedup),
1549                         crc);
1550         }
1551
1552         for (i = 0; i < 4; ++i) {
1553                 off = dedup[i].data_off;
1554                 cpu_ccfence();
1555                 if (dedup[i].data_crc != crc)
1556                         continue;
1557                 if ((1 << (int)(off & HAMMER2_OFF_MASK_RADIX)) != pblksize)
1558                         continue;
1559                 dio = hammer2_io_getquick(hmp, off, pblksize);
1560                 if (dio) {
1561                         dtmp = hammer2_io_data(dio, off),
1562                         mask = hammer2_dedup_mask(dio, off, pblksize);
1563                         if ((dio->dedup_alloc & mask) == mask &&
1564                             (dio->dedup_valid & mask) == mask &&
1565                             bcmp(data, dtmp, pblksize) == 0) {
1566                                 if (hammer2_debug & 0x40000) {
1567                                         kprintf("DEDUP SUCCESS %016jx\n",
1568                                                 (intmax_t)off);
1569                                 }
1570                                 hammer2_io_putblk(&dio);
1571                                 *datap = NULL;
1572                                 dedup[i].ticks = ticks;   /* update use */
1573                                 atomic_add_long(&hammer2_iod_file_wdedup,
1574                                                 pblksize);
1575
1576                                 return off;             /* RETURN */
1577                         }
1578                         hammer2_io_putblk(&dio);
1579                 }
1580         }
1581         return 0;
1582 }
1583
1584 /*
1585  * Poof.  Races are ok, if someone gets in and reuses a dedup offset
1586  * before or while we are clearing it they will also recover the freemap
1587  * entry (set it to fully allocated), so a bulkfree race can only set it
1588  * to a possibly-free state.
1589  *
1590  * XXX ok, well, not really sure races are ok but going to run with it
1591  *     for the moment.
1592  */
1593 void
1594 hammer2_dedup_clear(hammer2_dev_t *hmp)
1595 {
1596         int i;
1597
1598         for (i = 0; i < HAMMER2_DEDUP_HEUR_SIZE; ++i) {
1599                 hmp->heur_dedup[i].data_off = 0;
1600                 hmp->heur_dedup[i].ticks = ticks - 1;
1601         }
1602 }