hammer2 - Fix hammer2_chain and dedup issues
[dragonfly.git] / sys / vfs / hammer2 / hammer2_strategy.c
blob55b43646deb5a90d8baafb11d7e8353a41af6bbd
1 /*
2 * Copyright (c) 2011-2015 The DragonFly Project. All rights reserved.
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)
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
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.
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.
37 * This module handles low level logical file I/O (strategy) which backs
38 * the logical buffer cache.
40 * [De]compression, zero-block, check codes, and buffer cache operations
41 * for file data is handled here.
43 * Live dedup makes its home here as well.
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>
63 #include "hammer2.h"
64 #include "hammer2_lz4.h"
66 #include "zlib/hammer2_zlib.h"
68 struct objcache *cache_buffer_read;
69 struct objcache *cache_buffer_write;
72 * Strategy code (async logical file buffer I/O from system)
74 * Except for the transaction init (which should normally not block),
75 * we essentially run the strategy operation asynchronously via a XOP.
77 * XXX This isn't supposed to be able to deadlock against vfs_sync vfsync()
78 * calls but it has in the past when multiple flushes are queued.
80 * XXX We currently terminate the transaction once we get a quorum, otherwise
81 * the frontend can stall, but this can leave the remaining nodes with
82 * a potential flush conflict. We need to delay flushes on those nodes
83 * until running transactions complete separately from the normal
84 * transaction sequencing. FIXME TODO.
86 static void hammer2_strategy_xop_read(hammer2_thread_t *thr,
87 hammer2_xop_t *arg);
88 static void hammer2_strategy_xop_write(hammer2_thread_t *thr,
89 hammer2_xop_t *arg);
90 static int hammer2_strategy_read(struct vop_strategy_args *ap);
91 static int hammer2_strategy_write(struct vop_strategy_args *ap);
92 static void hammer2_strategy_read_completion(hammer2_chain_t *chain,
93 char *data, struct bio *bio);
95 static hammer2_off_t hammer2_dedup_lookup(hammer2_dev_t *hmp,
96 char **datap, int pblksize);
98 int h2timer[32];
99 int h2last;
100 int h2lid;
102 #define TIMER(which) do { \
103 if (h2last) \
104 h2timer[h2lid] += (int)(ticks - h2last);\
105 h2last = ticks; \
106 h2lid = which; \
107 } while(0)
110 hammer2_vop_strategy(struct vop_strategy_args *ap)
112 struct bio *biop;
113 struct buf *bp;
114 int error;
116 biop = ap->a_bio;
117 bp = biop->bio_buf;
119 switch(bp->b_cmd) {
120 case BUF_CMD_READ:
121 error = hammer2_strategy_read(ap);
122 ++hammer2_iod_file_read;
123 break;
124 case BUF_CMD_WRITE:
125 error = hammer2_strategy_write(ap);
126 ++hammer2_iod_file_write;
127 break;
128 default:
129 bp->b_error = error = EINVAL;
130 bp->b_flags |= B_ERROR;
131 biodone(biop);
132 break;
134 return (error);
138 * Return the largest contiguous physical disk range for the logical
139 * request, in bytes.
141 * (struct vnode *vp, off_t loffset, off_t *doffsetp, int *runp, int *runb)
143 * Basically disabled, the logical buffer write thread has to deal with
144 * buffers one-at-a-time. Note that this should not prevent cluster_read()
145 * from reading-ahead, it simply prevents it from trying form a single
146 * cluster buffer for the logical request. H2 already uses 64KB buffers!
149 hammer2_vop_bmap(struct vop_bmap_args *ap)
151 *ap->a_doffsetp = NOOFFSET;
152 if (ap->a_runp)
153 *ap->a_runp = 0;
154 if (ap->a_runb)
155 *ap->a_runb = 0;
156 return (EOPNOTSUPP);
159 /****************************************************************************
160 * READ SUPPORT *
161 ****************************************************************************/
163 * Callback used in read path in case that a block is compressed with LZ4.
165 static
166 void
167 hammer2_decompress_LZ4_callback(const char *data, u_int bytes, struct bio *bio)
169 struct buf *bp;
170 char *compressed_buffer;
171 int compressed_size;
172 int result;
174 bp = bio->bio_buf;
176 #if 0
177 if bio->bio_caller_info2.index &&
178 bio->bio_caller_info1.uvalue32 !=
179 crc32(bp->b_data, bp->b_bufsize) --- return error
180 #endif
182 KKASSERT(bp->b_bufsize <= HAMMER2_PBUFSIZE);
183 compressed_size = *(const int *)data;
184 KKASSERT((uint32_t)compressed_size <= bytes - sizeof(int));
186 compressed_buffer = objcache_get(cache_buffer_read, M_INTWAIT);
187 result = LZ4_decompress_safe(__DECONST(char *, &data[sizeof(int)]),
188 compressed_buffer,
189 compressed_size,
190 bp->b_bufsize);
191 if (result < 0) {
192 kprintf("READ PATH: Error during decompression."
193 "bio %016jx/%d\n",
194 (intmax_t)bio->bio_offset, bytes);
195 /* make sure it isn't random garbage */
196 bzero(compressed_buffer, bp->b_bufsize);
198 KKASSERT(result <= bp->b_bufsize);
199 bcopy(compressed_buffer, bp->b_data, bp->b_bufsize);
200 if (result < bp->b_bufsize)
201 bzero(bp->b_data + result, bp->b_bufsize - result);
202 objcache_put(cache_buffer_read, compressed_buffer);
203 bp->b_resid = 0;
204 bp->b_flags |= B_AGE;
208 * Callback used in read path in case that a block is compressed with ZLIB.
209 * It is almost identical to LZ4 callback, so in theory they can be unified,
210 * but we didn't want to make changes in bio structure for that.
212 static
213 void
214 hammer2_decompress_ZLIB_callback(const char *data, u_int bytes, struct bio *bio)
216 struct buf *bp;
217 char *compressed_buffer;
218 z_stream strm_decompress;
219 int result;
220 int ret;
222 bp = bio->bio_buf;
224 KKASSERT(bp->b_bufsize <= HAMMER2_PBUFSIZE);
225 strm_decompress.avail_in = 0;
226 strm_decompress.next_in = Z_NULL;
228 ret = inflateInit(&strm_decompress);
230 if (ret != Z_OK)
231 kprintf("HAMMER2 ZLIB: Fatal error in inflateInit.\n");
233 compressed_buffer = objcache_get(cache_buffer_read, M_INTWAIT);
234 strm_decompress.next_in = __DECONST(char *, data);
236 /* XXX supply proper size, subset of device bp */
237 strm_decompress.avail_in = bytes;
238 strm_decompress.next_out = compressed_buffer;
239 strm_decompress.avail_out = bp->b_bufsize;
241 ret = inflate(&strm_decompress, Z_FINISH);
242 if (ret != Z_STREAM_END) {
243 kprintf("HAMMER2 ZLIB: Fatar error during decompression.\n");
244 bzero(compressed_buffer, bp->b_bufsize);
246 bcopy(compressed_buffer, bp->b_data, bp->b_bufsize);
247 result = bp->b_bufsize - strm_decompress.avail_out;
248 if (result < bp->b_bufsize)
249 bzero(bp->b_data + result, strm_decompress.avail_out);
250 objcache_put(cache_buffer_read, compressed_buffer);
251 ret = inflateEnd(&strm_decompress);
253 bp->b_resid = 0;
254 bp->b_flags |= B_AGE;
258 * Logical buffer I/O, async read.
260 static
262 hammer2_strategy_read(struct vop_strategy_args *ap)
264 hammer2_xop_strategy_t *xop;
265 struct buf *bp;
266 struct bio *bio;
267 struct bio *nbio;
268 hammer2_inode_t *ip;
269 hammer2_key_t lbase;
271 bio = ap->a_bio;
272 bp = bio->bio_buf;
273 ip = VTOI(ap->a_vp);
274 nbio = push_bio(bio);
276 lbase = bio->bio_offset;
277 KKASSERT(((int)lbase & HAMMER2_PBUFMASK) == 0);
279 xop = hammer2_xop_alloc(ip, HAMMER2_XOP_STRATEGY);
280 xop->finished = 0;
281 xop->bio = bio;
282 xop->lbase = lbase;
283 hammer2_mtx_init(&xop->lock, "h2bior");
284 hammer2_xop_start(&xop->head, hammer2_strategy_xop_read);
285 /* asynchronous completion */
287 return(0);
291 * Per-node XOP (threaded), do a synchronous lookup of the chain and
292 * its data. The frontend is asynchronous, so we are also responsible
293 * for racing to terminate the frontend.
295 static
296 void
297 hammer2_strategy_xop_read(hammer2_thread_t *thr, hammer2_xop_t *arg)
299 hammer2_xop_strategy_t *xop = &arg->xop_strategy;
300 hammer2_chain_t *parent;
301 hammer2_chain_t *chain;
302 hammer2_key_t key_dummy;
303 hammer2_key_t lbase;
304 struct bio *bio;
305 struct buf *bp;
306 int cache_index = -1;
307 int error;
310 * Note that we can race completion of the bio supplied by
311 * the front-end so we cannot access it until we determine
312 * that we are the ones finishing it up.
314 TIMER(0);
315 lbase = xop->lbase;
318 * This is difficult to optimize. The logical buffer might be
319 * partially dirty (contain dummy zero-fill pages), which would
320 * mess up our crc calculation if we were to try a direct read.
321 * So for now we always double-buffer through the underlying
322 * storage.
324 * If not for the above problem we could conditionalize on
325 * (1) 64KB buffer, (2) one chain (not multi-master) and
326 * (3) !hammer2_double_buffer, and issue a direct read into the
327 * logical buffer.
329 parent = hammer2_inode_chain(xop->head.ip1, thr->clindex,
330 HAMMER2_RESOLVE_ALWAYS |
331 HAMMER2_RESOLVE_SHARED);
332 TIMER(1);
333 if (parent) {
334 chain = hammer2_chain_lookup(&parent, &key_dummy,
335 lbase, lbase,
336 &cache_index,
337 HAMMER2_LOOKUP_ALWAYS |
338 HAMMER2_LOOKUP_SHARED);
339 error = chain ? chain->error : 0;
340 } else {
341 error = EIO;
342 chain = NULL;
344 TIMER(2);
345 error = hammer2_xop_feed(&xop->head, chain, thr->clindex, error);
346 TIMER(3);
347 if (chain) {
348 hammer2_chain_unlock(chain);
349 hammer2_chain_drop(chain);
351 if (parent) {
352 hammer2_chain_unlock(parent);
353 hammer2_chain_drop(parent);
355 chain = NULL; /* safety */
356 parent = NULL; /* safety */
357 TIMER(4);
360 * Race to finish the frontend. First-to-complete. bio is only
361 * valid if we are determined to be the ones able to complete
362 * the operation.
364 if (xop->finished)
365 return;
366 hammer2_mtx_ex(&xop->lock);
367 if (xop->finished) {
368 hammer2_mtx_unlock(&xop->lock);
369 return;
371 bio = xop->bio;
372 bp = bio->bio_buf;
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.
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).
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.
388 error = hammer2_xop_collect(&xop->head, HAMMER2_XOP_COLLECT_NOWAIT);
389 TIMER(5);
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;
426 TIMER(6);
429 static
430 void
431 hammer2_strategy_read_completion(hammer2_chain_t *chain, char *data,
432 struct bio *bio)
434 struct buf *bp = bio->bio_buf;
436 if (chain->bref.type == HAMMER2_BREF_TYPE_INODE) {
438 * Copy from in-memory inode structure.
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) {
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.
455 * NOTE: Deduplication cannot be safely recorded for
456 * records without a check code.
458 hammer2_dedup_record(chain, NULL, data);
459 atomic_set_int(&chain->flags, HAMMER2_CHAIN_RELEASE);
462 * Decompression and copy.
464 switch (HAMMER2_DEC_COMP(chain->bref.methods)) {
465 case HAMMER2_COMP_LZ4:
466 hammer2_decompress_LZ4_callback(data, chain->bytes,
467 bio);
468 /* b_resid set by call */
469 break;
470 case HAMMER2_COMP_ZLIB:
471 hammer2_decompress_ZLIB_callback(data, chain->bytes,
472 bio);
473 /* b_resid set by call */
474 break;
475 case HAMMER2_COMP_NONE:
476 KKASSERT(chain->bytes <= bp->b_bcount);
477 bcopy(data, bp->b_data, chain->bytes);
478 if (chain->bytes < bp->b_bcount) {
479 bzero(bp->b_data + chain->bytes,
480 bp->b_bcount - chain->bytes);
482 bp->b_resid = 0;
483 bp->b_error = 0;
484 break;
485 default:
486 panic("hammer2_strategy_read: "
487 "unknown compression type");
489 } else {
490 panic("hammer2_strategy_read: unknown bref type");
494 /****************************************************************************
495 * WRITE SUPPORT *
496 ****************************************************************************/
499 * Functions for compression in threads,
500 * from hammer2_vnops.c
502 static void hammer2_write_file_core(char *data, hammer2_inode_t *ip,
503 hammer2_chain_t **parentp,
504 hammer2_key_t lbase, int ioflag, int pblksize,
505 hammer2_tid_t mtid, int *errorp);
506 static void hammer2_compress_and_write(char *data, hammer2_inode_t *ip,
507 hammer2_chain_t **parentp,
508 hammer2_key_t lbase, int ioflag, int pblksize,
509 hammer2_tid_t mtid, int *errorp,
510 int comp_algo, int check_algo);
511 static void hammer2_zero_check_and_write(char *data, hammer2_inode_t *ip,
512 hammer2_chain_t **parentp,
513 hammer2_key_t lbase, int ioflag, int pblksize,
514 hammer2_tid_t mtid, int *errorp,
515 int check_algo);
516 static int test_block_zeros(const char *buf, size_t bytes);
517 static void zero_write(char *data, hammer2_inode_t *ip,
518 hammer2_chain_t **parentp,
519 hammer2_key_t lbase,
520 hammer2_tid_t mtid, int *errorp);
521 static void hammer2_write_bp(hammer2_chain_t *chain, char *data,
522 int ioflag, int pblksize,
523 hammer2_tid_t mtid, int *errorp,
524 int check_algo);
526 static
528 hammer2_strategy_write(struct vop_strategy_args *ap)
530 hammer2_xop_strategy_t *xop;
531 hammer2_pfs_t *pmp;
532 struct bio *bio;
533 struct buf *bp;
534 hammer2_inode_t *ip;
536 bio = ap->a_bio;
537 bp = bio->bio_buf;
538 ip = VTOI(ap->a_vp);
539 pmp = ip->pmp;
541 hammer2_lwinprog_ref(pmp);
542 hammer2_trans_assert_strategy(pmp);
543 hammer2_trans_init(pmp, HAMMER2_TRANS_BUFCACHE);
545 xop = hammer2_xop_alloc(ip, HAMMER2_XOP_MODIFYING |
546 HAMMER2_XOP_STRATEGY);
547 xop->finished = 0;
548 xop->bio = bio;
549 xop->lbase = bio->bio_offset;
550 hammer2_mtx_init(&xop->lock, "h2biow");
551 hammer2_xop_start(&xop->head, hammer2_strategy_xop_write);
552 /* asynchronous completion */
554 hammer2_lwinprog_wait(pmp, hammer2_flush_pipe);
556 return(0);
560 * Per-node XOP (threaded). Write the logical buffer to the media.
562 * This is a bit problematic because there may be multiple target and
563 * any of them may be able to release the bp. In addition, if our
564 * particulr target is offline we don't want to block the bp (and thus
565 * the frontend). To accomplish this we copy the data to the per-thr
566 * scratch buffer.
568 static
569 void
570 hammer2_strategy_xop_write(hammer2_thread_t *thr, hammer2_xop_t *arg)
572 hammer2_xop_strategy_t *xop = &arg->xop_strategy;
573 hammer2_chain_t *parent;
574 hammer2_key_t lbase;
575 hammer2_inode_t *ip;
576 struct bio *bio;
577 struct buf *bp;
578 int error;
579 int lblksize;
580 int pblksize;
581 hammer2_off_t bio_offset;
582 char *bio_data;
585 * We can only access the bp/bio if the frontend has not yet
586 * completed.
588 if (xop->finished)
589 return;
590 hammer2_mtx_sh(&xop->lock);
591 if (xop->finished) {
592 hammer2_mtx_unlock(&xop->lock);
593 return;
596 lbase = xop->lbase;
597 bio = xop->bio; /* ephermal */
598 bp = bio->bio_buf; /* ephermal */
599 ip = xop->head.ip1; /* retained by ref */
600 bio_offset = bio->bio_offset;
601 bio_data = thr->scratch;
603 /* hammer2_trans_init(parent->hmp->spmp, HAMMER2_TRANS_BUFCACHE); */
605 lblksize = hammer2_calc_logical(ip, bio->bio_offset, &lbase, NULL);
606 pblksize = hammer2_calc_physical(ip, lbase);
607 bcopy(bp->b_data, bio_data, lblksize);
609 hammer2_mtx_unlock(&xop->lock);
610 bp = NULL; /* safety, illegal to access after unlock */
611 bio = NULL; /* safety, illegal to access after unlock */
614 * Actual operation
616 parent = hammer2_inode_chain(ip, thr->clindex, HAMMER2_RESOLVE_ALWAYS);
617 hammer2_write_file_core(bio_data, ip, &parent,
618 lbase, IO_ASYNC, pblksize,
619 xop->head.mtid, &error);
620 if (parent) {
621 hammer2_chain_unlock(parent);
622 hammer2_chain_drop(parent);
623 parent = NULL; /* safety */
625 hammer2_xop_feed(&xop->head, NULL, thr->clindex, error);
628 * Try to complete the operation on behalf of the front-end.
630 if (xop->finished)
631 return;
632 hammer2_mtx_ex(&xop->lock);
633 if (xop->finished) {
634 hammer2_mtx_unlock(&xop->lock);
635 return;
639 * Async operation has not completed and we now own the lock.
640 * Determine if we can complete the operation by issuing the
641 * frontend collection non-blocking.
643 * H2 double-buffers the data, setting B_NOTMETA on the logical
644 * buffer hints to the OS that the logical buffer should not be
645 * swapcached (since the device buffer can be).
647 error = hammer2_xop_collect(&xop->head, HAMMER2_XOP_COLLECT_NOWAIT);
649 if (error == EINPROGRESS) {
650 hammer2_mtx_unlock(&xop->lock);
651 return;
655 * Async operation has completed.
657 xop->finished = 1;
658 hammer2_mtx_unlock(&xop->lock);
660 bio = xop->bio; /* now owned by us */
661 bp = bio->bio_buf; /* now owned by us */
663 if (error == ENOENT || error == 0) {
664 bp->b_flags |= B_NOTMETA;
665 bp->b_resid = 0;
666 bp->b_error = 0;
667 biodone(bio);
668 } else {
669 kprintf("strategy_xop_write: error %d loff=%016jx\n",
670 error, bp->b_loffset);
671 bp->b_flags |= B_ERROR;
672 bp->b_error = EIO;
673 biodone(bio);
675 hammer2_xop_retire(&xop->head, HAMMER2_XOPMASK_VOP);
676 hammer2_trans_assert_strategy(ip->pmp);
677 hammer2_lwinprog_drop(ip->pmp);
678 hammer2_trans_done(ip->pmp);
682 * Wait for pending I/O to complete
684 void
685 hammer2_bioq_sync(hammer2_pfs_t *pmp)
687 hammer2_lwinprog_wait(pmp, 0);
691 * Create a new cluster at (cparent, lbase) and assign physical storage,
692 * returning a cluster suitable for I/O. The cluster will be in a modified
693 * state.
695 * cparent can wind up being anything.
697 * If datap is not NULL, *datap points to the real data we intend to write.
698 * If we can dedup the storage location we set *datap to NULL to indicate
699 * to the caller that a dedup occurred.
701 * NOTE: Special case for data embedded in inode.
703 static
704 hammer2_chain_t *
705 hammer2_assign_physical(hammer2_inode_t *ip, hammer2_chain_t **parentp,
706 hammer2_key_t lbase, int pblksize,
707 hammer2_tid_t mtid, char **datap, int *errorp)
709 hammer2_chain_t *chain;
710 hammer2_key_t key_dummy;
711 hammer2_off_t dedup_off;
712 int pradix = hammer2_getradix(pblksize);
713 int cache_index = -1;
716 * Locate the chain associated with lbase, return a locked chain.
717 * However, do not instantiate any data reference (which utilizes a
718 * device buffer) because we will be using direct IO via the
719 * logical buffer cache buffer.
721 *errorp = 0;
722 KKASSERT(pblksize >= HAMMER2_ALLOC_MIN);
723 retry:
724 TIMER(30);
725 chain = hammer2_chain_lookup(parentp, &key_dummy,
726 lbase, lbase,
727 &cache_index,
728 HAMMER2_LOOKUP_NODATA);
731 * The lookup code should not return a DELETED chain to us, unless
732 * its a short-file embedded in the inode. Then it is possible for
733 * the lookup to return a deleted inode.
735 if (chain && (chain->flags & HAMMER2_CHAIN_DELETED) &&
736 chain->bref.type != HAMMER2_BREF_TYPE_INODE) {
737 kprintf("assign physical deleted chain @ "
738 "%016jx (%016jx.%02x) ip %016jx\n",
739 lbase, chain->bref.data_off, chain->bref.type,
740 ip->meta.inum);
741 Debugger("bleh");
744 if (chain == NULL) {
746 * We found a hole, create a new chain entry.
748 * NOTE: DATA chains are created without device backing
749 * store (nor do we want any).
751 dedup_off = hammer2_dedup_lookup((*parentp)->hmp, datap,
752 pblksize);
753 *errorp = hammer2_chain_create(parentp, &chain,
754 ip->pmp,
755 HAMMER2_ENC_CHECK(ip->meta.check_algo) |
756 HAMMER2_ENC_COMP(HAMMER2_COMP_NONE),
757 lbase, HAMMER2_PBUFRADIX,
758 HAMMER2_BREF_TYPE_DATA,
759 pblksize, mtid,
760 dedup_off, 0);
761 if (chain == NULL) {
762 panic("hammer2_chain_create: par=%p error=%d\n",
763 *parentp, *errorp);
764 goto retry;
766 /*ip->delta_dcount += pblksize;*/
767 } else {
768 switch (chain->bref.type) {
769 case HAMMER2_BREF_TYPE_INODE:
771 * The data is embedded in the inode, which requires
772 * a bit more finess.
774 hammer2_chain_modify_ip(ip, chain, mtid, 0);
775 break;
776 case HAMMER2_BREF_TYPE_DATA:
777 dedup_off = hammer2_dedup_lookup(chain->hmp, datap,
778 pblksize);
779 if (chain->bytes != pblksize) {
780 hammer2_chain_resize(chain,
781 mtid, dedup_off,
782 pradix,
783 HAMMER2_MODIFY_OPTDATA);
787 * DATA buffers must be marked modified whether the
788 * data is in a logical buffer or not. We also have
789 * to make this call to fixup the chain data pointers
790 * after resizing in case this is an encrypted or
791 * compressed buffer.
793 hammer2_chain_modify(chain, mtid, dedup_off,
794 HAMMER2_MODIFY_OPTDATA);
795 break;
796 default:
797 panic("hammer2_assign_physical: bad type");
798 /* NOT REACHED */
799 break;
802 TIMER(31);
803 return (chain);
807 * hammer2_write_file_core() - hammer2_write_thread() helper
809 * The core write function which determines which path to take
810 * depending on compression settings. We also have to locate the
811 * related chains so we can calculate and set the check data for
812 * the blockref.
814 static
815 void
816 hammer2_write_file_core(char *data, hammer2_inode_t *ip,
817 hammer2_chain_t **parentp,
818 hammer2_key_t lbase, int ioflag, int pblksize,
819 hammer2_tid_t mtid, int *errorp)
821 hammer2_chain_t *chain;
822 char *bdata;
824 *errorp = 0;
826 switch(HAMMER2_DEC_ALGO(ip->meta.comp_algo)) {
827 case HAMMER2_COMP_NONE:
829 * We have to assign physical storage to the buffer
830 * we intend to dirty or write now to avoid deadlocks
831 * in the strategy code later.
833 * This can return NOOFFSET for inode-embedded data.
834 * The strategy code will take care of it in that case.
836 bdata = data;
837 chain = hammer2_assign_physical(ip, parentp, lbase, pblksize,
838 mtid, &bdata, errorp);
839 if (chain->bref.type == HAMMER2_BREF_TYPE_INODE) {
840 hammer2_inode_data_t *wipdata;
842 wipdata = &chain->data->ipdata;
843 KKASSERT(wipdata->meta.op_flags &
844 HAMMER2_OPFLAG_DIRECTDATA);
845 bcopy(data, wipdata->u.data, HAMMER2_EMBEDDED_BYTES);
846 ++hammer2_iod_file_wembed;
847 } else if (bdata == NULL) {
849 * Copy of data already present on-media.
851 chain->bref.methods =
852 HAMMER2_ENC_COMP(HAMMER2_COMP_NONE) +
853 HAMMER2_ENC_CHECK(ip->meta.check_algo);
854 hammer2_chain_setcheck(chain, data);
855 } else {
856 hammer2_write_bp(chain, data, ioflag, pblksize,
857 mtid, errorp, ip->meta.check_algo);
859 if (chain) {
860 hammer2_chain_unlock(chain);
861 hammer2_chain_drop(chain);
863 break;
864 case HAMMER2_COMP_AUTOZERO:
866 * Check for zero-fill only
868 hammer2_zero_check_and_write(data, ip, parentp,
869 lbase, ioflag, pblksize,
870 mtid, errorp,
871 ip->meta.check_algo);
872 break;
873 case HAMMER2_COMP_LZ4:
874 case HAMMER2_COMP_ZLIB:
875 default:
877 * Check for zero-fill and attempt compression.
879 hammer2_compress_and_write(data, ip, parentp,
880 lbase, ioflag, pblksize,
881 mtid, errorp,
882 ip->meta.comp_algo,
883 ip->meta.check_algo);
884 break;
889 * Helper
891 * Generic function that will perform the compression in compression
892 * write path. The compression algorithm is determined by the settings
893 * obtained from inode.
895 static
896 void
897 hammer2_compress_and_write(char *data, hammer2_inode_t *ip,
898 hammer2_chain_t **parentp,
899 hammer2_key_t lbase, int ioflag, int pblksize,
900 hammer2_tid_t mtid, int *errorp, int comp_algo, int check_algo)
902 hammer2_chain_t *chain;
903 int comp_size;
904 int comp_block_size;
905 char *comp_buffer;
906 char *bdata;
909 * An all-zeros write creates a hole unless the check code
910 * is disabled. When the check code is disabled all writes
911 * are done in-place, including any all-zeros writes.
913 * NOTE: A snapshot will still force a copy-on-write
914 * (see the HAMMER2_CHECK_NONE in hammer2_chain.c).
916 if (check_algo != HAMMER2_CHECK_NONE &&
917 test_block_zeros(data, pblksize)) {
918 zero_write(data, ip, parentp, lbase, mtid, errorp);
919 return;
923 * Compression requested. Try to compress the block. We store
924 * the data normally if we cannot sufficiently compress it.
926 * We have a heuristic to detect files which are mostly
927 * uncompressable and avoid the compression attempt in that
928 * case. If the compression heuristic is turned off, we always
929 * try to compress.
931 comp_size = 0;
932 comp_buffer = NULL;
934 KKASSERT(pblksize / 2 <= 32768);
936 if (ip->comp_heuristic < 8 || (ip->comp_heuristic & 7) == 0 ||
937 hammer2_always_compress) {
938 z_stream strm_compress;
939 int comp_level;
940 int ret;
942 switch(HAMMER2_DEC_ALGO(comp_algo)) {
943 case HAMMER2_COMP_LZ4:
944 comp_buffer = objcache_get(cache_buffer_write,
945 M_INTWAIT);
946 comp_size = LZ4_compress_limitedOutput(
947 data,
948 &comp_buffer[sizeof(int)],
949 pblksize,
950 pblksize / 2 - sizeof(int));
952 * We need to prefix with the size, LZ4
953 * doesn't do it for us. Add the related
954 * overhead.
956 *(int *)comp_buffer = comp_size;
957 if (comp_size)
958 comp_size += sizeof(int);
959 break;
960 case HAMMER2_COMP_ZLIB:
961 comp_level = HAMMER2_DEC_LEVEL(comp_algo);
962 if (comp_level == 0)
963 comp_level = 6; /* default zlib compression */
964 else if (comp_level < 6)
965 comp_level = 6;
966 else if (comp_level > 9)
967 comp_level = 9;
968 ret = deflateInit(&strm_compress, comp_level);
969 if (ret != Z_OK) {
970 kprintf("HAMMER2 ZLIB: fatal error "
971 "on deflateInit.\n");
974 comp_buffer = objcache_get(cache_buffer_write,
975 M_INTWAIT);
976 strm_compress.next_in = data;
977 strm_compress.avail_in = pblksize;
978 strm_compress.next_out = comp_buffer;
979 strm_compress.avail_out = pblksize / 2;
980 ret = deflate(&strm_compress, Z_FINISH);
981 if (ret == Z_STREAM_END) {
982 comp_size = pblksize / 2 -
983 strm_compress.avail_out;
984 } else {
985 comp_size = 0;
987 ret = deflateEnd(&strm_compress);
988 break;
989 default:
990 kprintf("Error: Unknown compression method.\n");
991 kprintf("Comp_method = %d.\n", comp_algo);
992 break;
996 if (comp_size == 0) {
998 * compression failed or turned off
1000 comp_block_size = pblksize; /* safety */
1001 if (++ip->comp_heuristic > 128)
1002 ip->comp_heuristic = 8;
1003 } else {
1005 * compression succeeded
1007 ip->comp_heuristic = 0;
1008 if (comp_size <= 1024) {
1009 comp_block_size = 1024;
1010 } else if (comp_size <= 2048) {
1011 comp_block_size = 2048;
1012 } else if (comp_size <= 4096) {
1013 comp_block_size = 4096;
1014 } else if (comp_size <= 8192) {
1015 comp_block_size = 8192;
1016 } else if (comp_size <= 16384) {
1017 comp_block_size = 16384;
1018 } else if (comp_size <= 32768) {
1019 comp_block_size = 32768;
1020 } else {
1021 panic("hammer2: WRITE PATH: "
1022 "Weird comp_size value.");
1023 /* NOT REACHED */
1024 comp_block_size = pblksize;
1028 * Must zero the remainder or dedup (which operates on a
1029 * physical block basis) will not find matches.
1031 if (comp_size < comp_block_size) {
1032 bzero(comp_buffer + comp_size,
1033 comp_block_size - comp_size);
1038 * Assign physical storage, data will be set to NULL if a live-dedup
1039 * was successful.
1041 bdata = comp_size ? comp_buffer : data;
1042 chain = hammer2_assign_physical(ip, parentp, lbase, comp_block_size,
1043 mtid, &bdata, errorp);
1045 if (*errorp) {
1046 kprintf("WRITE PATH: An error occurred while "
1047 "assigning physical space.\n");
1048 KKASSERT(chain == NULL);
1049 goto done;
1052 if (chain->bref.type == HAMMER2_BREF_TYPE_INODE) {
1053 hammer2_inode_data_t *wipdata;
1055 hammer2_chain_modify_ip(ip, chain, mtid, 0);
1056 wipdata = &chain->data->ipdata;
1057 KKASSERT(wipdata->meta.op_flags & HAMMER2_OPFLAG_DIRECTDATA);
1058 bcopy(data, wipdata->u.data, HAMMER2_EMBEDDED_BYTES);
1059 ++hammer2_iod_file_wembed;
1060 } else if (bdata == NULL) {
1062 * Live deduplication, a copy of the data is already present
1063 * on the media.
1065 if (comp_size) {
1066 chain->bref.methods =
1067 HAMMER2_ENC_COMP(comp_algo) +
1068 HAMMER2_ENC_CHECK(check_algo);
1069 } else {
1070 chain->bref.methods =
1071 HAMMER2_ENC_COMP(
1072 HAMMER2_COMP_NONE) +
1073 HAMMER2_ENC_CHECK(check_algo);
1075 bdata = comp_size ? comp_buffer : data;
1076 hammer2_chain_setcheck(chain, bdata);
1077 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_INITIAL);
1078 } else {
1079 hammer2_io_t *dio;
1081 KKASSERT(chain->flags & HAMMER2_CHAIN_MODIFIED);
1083 switch(chain->bref.type) {
1084 case HAMMER2_BREF_TYPE_INODE:
1085 panic("hammer2_write_bp: unexpected inode\n");
1086 break;
1087 case HAMMER2_BREF_TYPE_DATA:
1089 * Optimize out the read-before-write
1090 * if possible.
1092 *errorp = hammer2_io_newnz(chain->hmp,
1093 chain->bref.type,
1094 chain->bref.data_off,
1095 chain->bytes,
1096 &dio);
1097 if (*errorp) {
1098 hammer2_io_brelse(&dio);
1099 kprintf("hammer2: WRITE PATH: "
1100 "dbp bread error\n");
1101 break;
1103 bdata = hammer2_io_data(dio, chain->bref.data_off);
1106 * When loading the block make sure we don't
1107 * leave garbage after the compressed data.
1109 if (comp_size) {
1110 chain->bref.methods =
1111 HAMMER2_ENC_COMP(comp_algo) +
1112 HAMMER2_ENC_CHECK(check_algo);
1113 bcopy(comp_buffer, bdata, comp_size);
1114 } else {
1115 chain->bref.methods =
1116 HAMMER2_ENC_COMP(
1117 HAMMER2_COMP_NONE) +
1118 HAMMER2_ENC_CHECK(check_algo);
1119 bcopy(data, bdata, pblksize);
1123 * The flush code doesn't calculate check codes for
1124 * file data (doing so can result in excessive I/O),
1125 * so we do it here.
1127 hammer2_chain_setcheck(chain, bdata);
1130 * Device buffer is now valid, chain is no longer in
1131 * the initial state.
1133 * (No blockref table worries with file data)
1135 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_INITIAL);
1136 hammer2_dedup_record(chain, dio, bdata);
1138 /* Now write the related bdp. */
1139 if (ioflag & IO_SYNC) {
1141 * Synchronous I/O requested.
1143 hammer2_io_bwrite(&dio);
1145 } else if ((ioflag & IO_DIRECT) &&
1146 loff + n == pblksize) {
1147 hammer2_io_bdwrite(&dio);
1149 } else if (ioflag & IO_ASYNC) {
1150 hammer2_io_bawrite(&dio);
1151 } else {
1152 hammer2_io_bdwrite(&dio);
1154 break;
1155 default:
1156 panic("hammer2_write_bp: bad chain type %d\n",
1157 chain->bref.type);
1158 /* NOT REACHED */
1159 break;
1162 done:
1163 if (chain) {
1164 hammer2_chain_unlock(chain);
1165 hammer2_chain_drop(chain);
1167 if (comp_buffer)
1168 objcache_put(cache_buffer_write, comp_buffer);
1172 * Helper
1174 * Function that performs zero-checking and writing without compression,
1175 * it corresponds to default zero-checking path.
1177 static
1178 void
1179 hammer2_zero_check_and_write(char *data, hammer2_inode_t *ip,
1180 hammer2_chain_t **parentp,
1181 hammer2_key_t lbase, int ioflag, int pblksize,
1182 hammer2_tid_t mtid, int *errorp,
1183 int check_algo)
1185 hammer2_chain_t *chain;
1186 char *bdata;
1188 if (check_algo != HAMMER2_CHECK_NONE &&
1189 test_block_zeros(data, pblksize)) {
1191 * An all-zeros write creates a hole unless the check code
1192 * is disabled. When the check code is disabled all writes
1193 * are done in-place, including any all-zeros writes.
1195 * NOTE: A snapshot will still force a copy-on-write
1196 * (see the HAMMER2_CHECK_NONE in hammer2_chain.c).
1198 zero_write(data, ip, parentp, lbase, mtid, errorp);
1199 } else {
1201 * Normal write
1203 bdata = data;
1204 chain = hammer2_assign_physical(ip, parentp, lbase, pblksize,
1205 mtid, &bdata, errorp);
1206 if (bdata) {
1207 hammer2_write_bp(chain, data, ioflag, pblksize,
1208 mtid, errorp, check_algo);
1209 } else {
1210 /* dedup occurred */
1211 chain->bref.methods =
1212 HAMMER2_ENC_COMP(HAMMER2_COMP_NONE) +
1213 HAMMER2_ENC_CHECK(check_algo);
1214 hammer2_chain_setcheck(chain, data);
1216 if (chain) {
1217 hammer2_chain_unlock(chain);
1218 hammer2_chain_drop(chain);
1224 * Helper
1226 * A function to test whether a block of data contains only zeros,
1227 * returns TRUE (non-zero) if the block is all zeros.
1229 static
1231 test_block_zeros(const char *buf, size_t bytes)
1233 size_t i;
1235 for (i = 0; i < bytes; i += sizeof(long)) {
1236 if (*(const long *)(buf + i) != 0)
1237 return (0);
1239 return (1);
1243 * Helper
1245 * Function to "write" a block that contains only zeros.
1247 static
1248 void
1249 zero_write(char *data, hammer2_inode_t *ip,
1250 hammer2_chain_t **parentp,
1251 hammer2_key_t lbase, hammer2_tid_t mtid, int *errorp)
1253 hammer2_chain_t *chain;
1254 hammer2_key_t key_dummy;
1255 int cache_index = -1;
1257 *errorp = 0;
1258 chain = hammer2_chain_lookup(parentp, &key_dummy,
1259 lbase, lbase,
1260 &cache_index,
1261 HAMMER2_LOOKUP_NODATA);
1262 if (chain) {
1263 if (chain->bref.type == HAMMER2_BREF_TYPE_INODE) {
1264 hammer2_inode_data_t *wipdata;
1266 hammer2_chain_modify_ip(ip, chain, mtid, 0);
1267 wipdata = &chain->data->ipdata;
1268 KKASSERT(wipdata->meta.op_flags &
1269 HAMMER2_OPFLAG_DIRECTDATA);
1270 bzero(wipdata->u.data, HAMMER2_EMBEDDED_BYTES);
1271 ++hammer2_iod_file_wembed;
1272 } else {
1273 hammer2_chain_delete(*parentp, chain,
1274 mtid, HAMMER2_DELETE_PERMANENT);
1275 ++hammer2_iod_file_wzero;
1277 hammer2_chain_unlock(chain);
1278 hammer2_chain_drop(chain);
1279 } else {
1280 ++hammer2_iod_file_wzero;
1285 * Helper
1287 * Function to write the data as it is, without performing any sort of
1288 * compression. This function is used in path without compression and
1289 * default zero-checking path.
1291 static
1292 void
1293 hammer2_write_bp(hammer2_chain_t *chain, char *data, int ioflag,
1294 int pblksize,
1295 hammer2_tid_t mtid, int *errorp, int check_algo)
1297 hammer2_inode_data_t *wipdata;
1298 hammer2_io_t *dio;
1299 char *bdata;
1300 int error;
1302 error = 0; /* XXX TODO below */
1304 KKASSERT(chain->flags & HAMMER2_CHAIN_MODIFIED);
1306 switch(chain->bref.type) {
1307 case HAMMER2_BREF_TYPE_INODE:
1308 wipdata = &chain->data->ipdata;
1309 KKASSERT(wipdata->meta.op_flags & HAMMER2_OPFLAG_DIRECTDATA);
1310 bcopy(data, wipdata->u.data, HAMMER2_EMBEDDED_BYTES);
1311 error = 0;
1312 ++hammer2_iod_file_wembed;
1313 break;
1314 case HAMMER2_BREF_TYPE_DATA:
1315 error = hammer2_io_newnz(chain->hmp,
1316 chain->bref.type,
1317 chain->bref.data_off,
1318 chain->bytes, &dio);
1319 if (error) {
1320 hammer2_io_bqrelse(&dio);
1321 kprintf("hammer2: WRITE PATH: "
1322 "dbp bread error\n");
1323 break;
1325 bdata = hammer2_io_data(dio, chain->bref.data_off);
1327 chain->bref.methods = HAMMER2_ENC_COMP(HAMMER2_COMP_NONE) +
1328 HAMMER2_ENC_CHECK(check_algo);
1329 bcopy(data, bdata, chain->bytes);
1332 * The flush code doesn't calculate check codes for
1333 * file data (doing so can result in excessive I/O),
1334 * so we do it here.
1336 hammer2_chain_setcheck(chain, bdata);
1339 * Device buffer is now valid, chain is no longer in
1340 * the initial state.
1342 * (No blockref table worries with file data)
1344 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_INITIAL);
1345 hammer2_dedup_record(chain, dio, bdata);
1347 if (ioflag & IO_SYNC) {
1349 * Synchronous I/O requested.
1351 hammer2_io_bwrite(&dio);
1353 } else if ((ioflag & IO_DIRECT) &&
1354 loff + n == pblksize) {
1355 hammer2_io_bdwrite(&dio);
1357 } else if (ioflag & IO_ASYNC) {
1358 hammer2_io_bawrite(&dio);
1359 } else {
1360 hammer2_io_bdwrite(&dio);
1362 break;
1363 default:
1364 panic("hammer2_write_bp: bad chain type %d\n",
1365 chain->bref.type);
1366 /* NOT REACHED */
1367 error = 0;
1368 break;
1370 KKASSERT(error == 0); /* XXX TODO */
1371 *errorp = error;
1375 * LIVE DEDUP HEURISTICS
1377 * Record media and crc information for possible dedup operation. Note
1378 * that the dedup mask bits must also be set in the related DIO for a dedup
1379 * to be fully validated (which is handled in the freemap allocation code).
1381 * WARNING! This code is SMP safe but the heuristic allows SMP collisions.
1382 * All fields must be loaded into locals and validated.
1384 * WARNING! Should only be used for file data and directory entries,
1385 * hammer2_chain_modify() only checks for the dedup case on data
1386 * chains. Also, dedup data can only be recorded for committed
1387 * chains (so NOT strategy writes which can undergo further
1388 * modification after the fact!).
1390 void
1391 hammer2_dedup_record(hammer2_chain_t *chain, hammer2_io_t *dio, char *data)
1393 hammer2_dev_t *hmp;
1394 hammer2_dedup_t *dedup;
1395 uint64_t crc;
1396 uint64_t mask;
1397 int best = 0;
1398 int i;
1399 int dticks;
1402 * We can only record a dedup if we have media data to test against.
1403 * If dedup is not enabled, return early, which allows a chain to
1404 * remain marked MODIFIED (which might have benefits in special
1405 * situations, though typically it does not).
1407 if (hammer2_dedup_enable == 0)
1408 return;
1409 if (dio == NULL) {
1410 dio = chain->dio;
1411 if (dio == NULL)
1412 return;
1415 #if 0
1417 * Only committed data can be recorded for de-duplication, otherwise
1418 * the contents may change out from under us. So, on read if the
1419 * chain is not modified, and on flush when the chain is committed.
1421 if ((chain->flags &
1422 (HAMMER2_CHAIN_MODIFIED | HAMMER2_CHAIN_INITIAL)) == 0) {
1423 return;
1425 #endif
1427 hmp = chain->hmp;
1429 switch(HAMMER2_DEC_CHECK(chain->bref.methods)) {
1430 case HAMMER2_CHECK_ISCSI32:
1432 * XXX use the built-in crc (the dedup lookup sequencing
1433 * needs to be fixed so the check code is already present
1434 * when dedup_lookup is called)
1436 #if 0
1437 crc = (uint64_t)(uint32_t)chain->bref.check.iscsi32.value;
1438 #endif
1439 crc = XXH64(data, chain->bytes, XXH_HAMMER2_SEED);
1440 break;
1441 case HAMMER2_CHECK_XXHASH64:
1442 crc = chain->bref.check.xxhash64.value;
1443 break;
1444 case HAMMER2_CHECK_SHA192:
1446 * XXX use the built-in crc (the dedup lookup sequencing
1447 * needs to be fixed so the check code is already present
1448 * when dedup_lookup is called)
1450 #if 0
1451 crc = ((uint64_t *)chain->bref.check.sha192.data)[0] ^
1452 ((uint64_t *)chain->bref.check.sha192.data)[1] ^
1453 ((uint64_t *)chain->bref.check.sha192.data)[2];
1454 #endif
1455 crc = XXH64(data, chain->bytes, XXH_HAMMER2_SEED);
1456 break;
1457 default:
1459 * Cannot dedup without a check code
1461 * NOTE: In particular, CHECK_NONE allows a sector to be
1462 * overwritten without copy-on-write, recording
1463 * a dedup block for a CHECK_NONE object would be
1464 * a disaster!
1466 return;
1468 dedup = &hmp->heur_dedup[crc & (HAMMER2_DEDUP_HEUR_MASK & ~3)];
1469 for (i = 0; i < 4; ++i) {
1470 if (dedup[i].data_crc == crc) {
1471 best = i;
1472 break;
1474 dticks = (int)(dedup[i].ticks - dedup[best].ticks);
1475 if (dticks < 0 || dticks > hz * 60 * 30)
1476 best = i;
1478 dedup += best;
1479 if (hammer2_debug & 0x40000) {
1480 kprintf("REC %04x %016jx %016jx\n",
1481 (int)(dedup - hmp->heur_dedup),
1482 crc,
1483 chain->bref.data_off);
1485 dedup->ticks = ticks;
1486 dedup->data_off = chain->bref.data_off;
1487 dedup->data_crc = crc;
1490 * Set the valid bits for the dedup only after we know the data
1491 * buffer has been updated. The alloc bits were set (and the valid
1492 * bits cleared) when the media was allocated.
1494 * This is done in two stages becuase the bulkfree code can race
1495 * the gap between allocation and data population. Both masks must
1496 * be set before a bcmp/dedup operation is able to use the block.
1498 mask = hammer2_dedup_mask(dio, chain->bref.data_off, chain->bytes);
1499 atomic_set_64(&dio->dedup_valid, mask);
1502 * Once we record the dedup the chain must be marked clean to
1503 * prevent reuse of the underlying block. Remember that this
1504 * write occurs when the buffer cache is flushed (i.e. on sync(),
1505 * fsync(), filesystem periodic sync, or when the kernel needs to
1506 * flush a buffer), and not whenever the user write()s.
1508 if (chain->flags & HAMMER2_CHAIN_MODIFIED) {
1509 atomic_clear_int(&chain->flags, HAMMER2_CHAIN_MODIFIED);
1510 atomic_add_long(&hammer2_count_modified_chains, -1);
1511 if (chain->pmp)
1512 hammer2_pfs_memory_wakeup(chain->pmp);
1516 static
1517 hammer2_off_t
1518 hammer2_dedup_lookup(hammer2_dev_t *hmp, char **datap, int pblksize)
1520 hammer2_dedup_t *dedup;
1521 hammer2_io_t *dio;
1522 hammer2_off_t off;
1523 uint64_t crc;
1524 uint64_t mask;
1525 char *data;
1526 char *dtmp;
1527 int i;
1529 if (hammer2_dedup_enable == 0)
1530 return 0;
1531 data = *datap;
1532 if (data == NULL)
1533 return 0;
1536 * XXX use the built-in crc (the dedup lookup sequencing
1537 * needs to be fixed so the check code is already present
1538 * when dedup_lookup is called)
1540 crc = XXH64(data, pblksize, XXH_HAMMER2_SEED);
1541 dedup = &hmp->heur_dedup[crc & (HAMMER2_DEDUP_HEUR_MASK & ~3)];
1543 if (hammer2_debug & 0x40000) {
1544 kprintf("LOC %04x/4 %016jx\n",
1545 (int)(dedup - hmp->heur_dedup),
1546 crc);
1549 for (i = 0; i < 4; ++i) {
1550 off = dedup[i].data_off;
1551 cpu_ccfence();
1552 if (dedup[i].data_crc != crc)
1553 continue;
1554 if ((1 << (int)(off & HAMMER2_OFF_MASK_RADIX)) != pblksize)
1555 continue;
1556 dio = hammer2_io_getquick(hmp, off, pblksize, 0);
1557 if (dio) {
1558 dtmp = hammer2_io_data(dio, off),
1559 mask = hammer2_dedup_mask(dio, off, pblksize);
1560 if ((dio->dedup_alloc & mask) == mask &&
1561 (dio->dedup_valid & mask) == mask &&
1562 bcmp(data, dtmp, pblksize) == 0) {
1563 if (hammer2_debug & 0x40000) {
1564 kprintf("DEDUP SUCCESS %016jx\n",
1565 (intmax_t)off);
1567 hammer2_io_putblk(&dio);
1568 *datap = NULL;
1569 dedup[i].ticks = ticks; /* update use */
1570 atomic_add_long(&hammer2_iod_file_wdedup,
1571 pblksize);
1573 return off; /* RETURN */
1575 hammer2_io_putblk(&dio);
1578 return 0;
1582 * Poof. Races are ok, if someone gets in and reuses a dedup offset
1583 * before or while we are clearing it they will also recover the freemap
1584 * entry (set it to fully allocated), so a bulkfree race can only set it
1585 * to a possibly-free state.
1587 * XXX ok, well, not really sure races are ok but going to run with it
1588 * for the moment.
1590 void
1591 hammer2_dedup_clear(hammer2_dev_t *hmp)
1593 int i;
1595 for (i = 0; i < HAMMER2_DEDUP_HEUR_SIZE; ++i) {
1596 hmp->heur_dedup[i].data_off = 0;
1597 hmp->heur_dedup[i].ticks = ticks - 1;