1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22 /*
23 * Copyright (c) 2009, 2010, Oracle and/or its affiliates. All rights reserved.
24 */
25
26 #include <sys/zfs_context.h>
27 #include <sys/spa.h>
28 #include <sys/spa_impl.h>
29 #include <sys/zio.h>
30 #include <sys/ddt.h>
31 #include <sys/zap.h>
32 #include <sys/dmu_tx.h>
33 #include <sys/arc.h>
34 #include <sys/dsl_pool.h>
35 #include <sys/zio_checksum.h>
36 #include <sys/zio_compress.h>
37 #include <sys/dsl_scan.h>
38
39 /*
40 * Enable/disable prefetching of dedup-ed blocks which are going to be freed.
41 */
42 int zfs_dedup_prefetch = 1;
43
44 static const ddt_ops_t *ddt_ops[DDT_TYPES] = {
45 &ddt_zap_ops,
46 };
47
48 static const char *ddt_class_name[DDT_CLASSES] = {
49 "ditto",
50 "duplicate",
51 "unique",
52 };
53
54 static void
55 ddt_object_create(ddt_t *ddt, enum ddt_type type, enum ddt_class class,
56 dmu_tx_t *tx)
57 {
58 spa_t *spa = ddt->ddt_spa;
59 objset_t *os = ddt->ddt_os;
60 uint64_t *objectp = &ddt->ddt_object[type][class];
61 boolean_t prehash = zio_checksum_table[ddt->ddt_checksum].ci_dedup;
62 char name[DDT_NAMELEN];
63
64 ddt_object_name(ddt, type, class, name);
65
66 ASSERT(*objectp == 0);
67 VERIFY(ddt_ops[type]->ddt_op_create(os, objectp, tx, prehash) == 0);
68 ASSERT(*objectp != 0);
69
70 VERIFY(zap_add(os, DMU_POOL_DIRECTORY_OBJECT, name,
71 sizeof (uint64_t), 1, objectp, tx) == 0);
72
73 VERIFY(zap_add(os, spa->spa_ddt_stat_object, name,
74 sizeof (uint64_t), sizeof (ddt_histogram_t) / sizeof (uint64_t),
75 &ddt->ddt_histogram[type][class], tx) == 0);
76 }
77
78 static void
79 ddt_object_destroy(ddt_t *ddt, enum ddt_type type, enum ddt_class class,
80 dmu_tx_t *tx)
81 {
82 spa_t *spa = ddt->ddt_spa;
83 objset_t *os = ddt->ddt_os;
84 uint64_t *objectp = &ddt->ddt_object[type][class];
85 char name[DDT_NAMELEN];
86
87 ddt_object_name(ddt, type, class, name);
88
89 ASSERT(*objectp != 0);
90 ASSERT(ddt_object_count(ddt, type, class) == 0);
91 ASSERT(ddt_histogram_empty(&ddt->ddt_histogram[type][class]));
92 VERIFY(zap_remove(os, DMU_POOL_DIRECTORY_OBJECT, name, tx) == 0);
93 VERIFY(zap_remove(os, spa->spa_ddt_stat_object, name, tx) == 0);
94 VERIFY(ddt_ops[type]->ddt_op_destroy(os, *objectp, tx) == 0);
95 bzero(&ddt->ddt_object_stats[type][class], sizeof (ddt_object_t));
96
97 *objectp = 0;
98 }
99
100 static int
101 ddt_object_load(ddt_t *ddt, enum ddt_type type, enum ddt_class class)
102 {
103 ddt_object_t *ddo = &ddt->ddt_object_stats[type][class];
104 dmu_object_info_t doi;
105 char name[DDT_NAMELEN];
106 int error;
107
108 ddt_object_name(ddt, type, class, name);
109
110 error = zap_lookup(ddt->ddt_os, DMU_POOL_DIRECTORY_OBJECT, name,
111 sizeof (uint64_t), 1, &ddt->ddt_object[type][class]);
112
113 if (error)
114 return (error);
115
116 error = zap_lookup(ddt->ddt_os, ddt->ddt_spa->spa_ddt_stat_object, name,
117 sizeof (uint64_t), sizeof (ddt_histogram_t) / sizeof (uint64_t),
118 &ddt->ddt_histogram[type][class]);
119
120 /*
121 * Seed the cached statistics.
122 */
123 VERIFY(ddt_object_info(ddt, type, class, &doi) == 0);
124
125 ddo->ddo_count = ddt_object_count(ddt, type, class);
126 ddo->ddo_dspace = doi.doi_physical_blocks_512 << 9;
127 ddo->ddo_mspace = doi.doi_fill_count * doi.doi_data_block_size;
128
129 ASSERT(error == 0);
130 return (error);
131 }
132
133 static void
134 ddt_object_sync(ddt_t *ddt, enum ddt_type type, enum ddt_class class,
135 dmu_tx_t *tx)
136 {
137 ddt_object_t *ddo = &ddt->ddt_object_stats[type][class];
138 dmu_object_info_t doi;
139 char name[DDT_NAMELEN];
140
141 ddt_object_name(ddt, type, class, name);
142
143 VERIFY(zap_update(ddt->ddt_os, ddt->ddt_spa->spa_ddt_stat_object, name,
144 sizeof (uint64_t), sizeof (ddt_histogram_t) / sizeof (uint64_t),
145 &ddt->ddt_histogram[type][class], tx) == 0);
146
147 /*
148 * Cache DDT statistics; this is the only time they'll change.
149 */
150 VERIFY(ddt_object_info(ddt, type, class, &doi) == 0);
151
152 ddo->ddo_count = ddt_object_count(ddt, type, class);
153 ddo->ddo_dspace = doi.doi_physical_blocks_512 << 9;
154 ddo->ddo_mspace = doi.doi_fill_count * doi.doi_data_block_size;
155 }
156
157 static int
158 ddt_object_lookup(ddt_t *ddt, enum ddt_type type, enum ddt_class class,
159 ddt_entry_t *dde)
160 {
161 if (!ddt_object_exists(ddt, type, class))
162 return (ENOENT);
163
164 return (ddt_ops[type]->ddt_op_lookup(ddt->ddt_os,
165 ddt->ddt_object[type][class], dde));
166 }
167
168 static void
169 ddt_object_prefetch(ddt_t *ddt, enum ddt_type type, enum ddt_class class,
170 ddt_entry_t *dde)
171 {
172 if (!ddt_object_exists(ddt, type, class))
173 return;
174
175 ddt_ops[type]->ddt_op_prefetch(ddt->ddt_os,
176 ddt->ddt_object[type][class], dde);
177 }
178
179 int
180 ddt_object_update(ddt_t *ddt, enum ddt_type type, enum ddt_class class,
181 ddt_entry_t *dde, dmu_tx_t *tx)
182 {
183 ASSERT(ddt_object_exists(ddt, type, class));
184
185 return (ddt_ops[type]->ddt_op_update(ddt->ddt_os,
186 ddt->ddt_object[type][class], dde, tx));
187 }
188
189 static int
190 ddt_object_remove(ddt_t *ddt, enum ddt_type type, enum ddt_class class,
191 ddt_entry_t *dde, dmu_tx_t *tx)
192 {
193 ASSERT(ddt_object_exists(ddt, type, class));
194
195 return (ddt_ops[type]->ddt_op_remove(ddt->ddt_os,
196 ddt->ddt_object[type][class], dde, tx));
197 }
198
199 int
200 ddt_object_walk(ddt_t *ddt, enum ddt_type type, enum ddt_class class,
201 uint64_t *walk, ddt_entry_t *dde)
202 {
203 ASSERT(ddt_object_exists(ddt, type, class));
204
205 return (ddt_ops[type]->ddt_op_walk(ddt->ddt_os,
206 ddt->ddt_object[type][class], dde, walk));
207 }
208
209 uint64_t
210 ddt_object_count(ddt_t *ddt, enum ddt_type type, enum ddt_class class)
211 {
212 ASSERT(ddt_object_exists(ddt, type, class));
213
214 return (ddt_ops[type]->ddt_op_count(ddt->ddt_os,
215 ddt->ddt_object[type][class]));
216 }
217
218 int
219 ddt_object_info(ddt_t *ddt, enum ddt_type type, enum ddt_class class,
220 dmu_object_info_t *doi)
221 {
222 if (!ddt_object_exists(ddt, type, class))
223 return (ENOENT);
224
225 return (dmu_object_info(ddt->ddt_os, ddt->ddt_object[type][class],
226 doi));
227 }
228
229 boolean_t
230 ddt_object_exists(ddt_t *ddt, enum ddt_type type, enum ddt_class class)
231 {
232 return (!!ddt->ddt_object[type][class]);
233 }
234
235 void
236 ddt_object_name(ddt_t *ddt, enum ddt_type type, enum ddt_class class,
237 char *name)
238 {
239 (void) sprintf(name, DMU_POOL_DDT,
240 zio_checksum_table[ddt->ddt_checksum].ci_name,
241 ddt_ops[type]->ddt_op_name, ddt_class_name[class]);
242 }
243
244 void
245 ddt_bp_fill(const ddt_phys_t *ddp, blkptr_t *bp, uint64_t txg)
246 {
247 ASSERT(txg != 0);
248
249 for (int d = 0; d < SPA_DVAS_PER_BP; d++)
250 bp->blk_dva[d] = ddp->ddp_dva[d];
251 BP_SET_BIRTH(bp, txg, ddp->ddp_phys_birth);
252 }
253
254 void
255 ddt_bp_create(enum zio_checksum checksum,
256 const ddt_key_t *ddk, const ddt_phys_t *ddp, blkptr_t *bp)
257 {
258 BP_ZERO(bp);
259
260 if (ddp != NULL)
261 ddt_bp_fill(ddp, bp, ddp->ddp_phys_birth);
262
263 bp->blk_cksum = ddk->ddk_cksum;
264 bp->blk_fill = 1;
265
266 BP_SET_LSIZE(bp, DDK_GET_LSIZE(ddk));
267 BP_SET_PSIZE(bp, DDK_GET_PSIZE(ddk));
268 BP_SET_COMPRESS(bp, DDK_GET_COMPRESS(ddk));
269 BP_SET_CHECKSUM(bp, checksum);
270 BP_SET_TYPE(bp, DMU_OT_DEDUP);
271 BP_SET_LEVEL(bp, 0);
272 BP_SET_DEDUP(bp, 0);
273 BP_SET_BYTEORDER(bp, ZFS_HOST_BYTEORDER);
274 }
275
276 void
277 ddt_key_fill(ddt_key_t *ddk, const blkptr_t *bp)
278 {
279 ddk->ddk_cksum = bp->blk_cksum;
280 ddk->ddk_prop = 0;
281
282 DDK_SET_LSIZE(ddk, BP_GET_LSIZE(bp));
283 DDK_SET_PSIZE(ddk, BP_GET_PSIZE(bp));
284 DDK_SET_COMPRESS(ddk, BP_GET_COMPRESS(bp));
285 }
286
287 void
288 ddt_phys_fill(ddt_phys_t *ddp, const blkptr_t *bp)
289 {
290 ASSERT(ddp != NULL);
291 ASSERT(ddp->ddp_phys_birth == 0);
292
293 for (int d = 0; d < SPA_DVAS_PER_BP; d++)
294 ddp->ddp_dva[d] = bp->blk_dva[d];
295 ddp->ddp_phys_birth = BP_PHYSICAL_BIRTH(bp);
296 }
297
298 void
299 ddt_phys_clear(ddt_phys_t *ddp)
300 {
301 ASSERT(ddp != NULL);
302 if (ddp) {
303 bzero(ddp, sizeof (*ddp));
304 }
305 }
306
307 void
308 ddt_phys_addref(ddt_phys_t *ddp)
309 {
310 ASSERT(ddp != NULL);
311 if (ddp) {
312 ddp->ddp_refcnt++;
313 }
314 }
315
316 void
317 ddt_phys_decref(ddt_phys_t *ddp)
318 {
319 // ASSERT(ddp != NULL);
320 if (ddp) {
321 ASSERT((int64_t)ddp->ddp_refcnt > 0);
322 ddp->ddp_refcnt--;
323 }
324 }
325
326 void
327 ddt_phys_free(ddt_t *ddt, ddt_key_t *ddk, ddt_phys_t *ddp, uint64_t txg)
328 {
329 blkptr_t blk;
330
331 ddt_bp_create(ddt->ddt_checksum, ddk, ddp, &blk);
332 ddt_phys_clear(ddp);
333 zio_free(ddt->ddt_spa, txg, &blk);
334 }
335
336 ddt_phys_t *
337 ddt_phys_select(const ddt_entry_t *dde, const blkptr_t *bp)
338 {
339 ddt_phys_t *ddp = (ddt_phys_t *)dde->dde_phys;
340
341 for (int p = 0; p < DDT_PHYS_TYPES; p++, ddp++) {
342 if (DVA_EQUAL(BP_IDENTITY(bp), &ddp->ddp_dva[0]) &&
343 BP_PHYSICAL_BIRTH(bp) == ddp->ddp_phys_birth)
344 return (ddp);
345 }
346 (void) printf("ddt_phys_select() found nothing for "
347 "DVA[BP]=<%llu:%llx:%llx> and phys_birth[BP]=%llu\n",
348 (u_longlong_t)DVA_GET_VDEV(BP_IDENTITY(bp)),
349 (u_longlong_t)DVA_GET_OFFSET(BP_IDENTITY(bp)),
350 (u_longlong_t)DVA_GET_ASIZE(BP_IDENTITY(bp)),
351 (u_longlong_t)BP_PHYSICAL_BIRTH(bp)
352 );
353 return (NULL);
354 }
355
356 uint64_t
357 ddt_phys_total_refcnt(const ddt_entry_t *dde)
358 {
359 uint64_t refcnt = 0;
360
361 for (int p = DDT_PHYS_SINGLE; p <= DDT_PHYS_TRIPLE; p++)
362 refcnt += dde->dde_phys[p].ddp_refcnt;
363
364 return (refcnt);
365 }
366
367 static void
368 ddt_stat_generate(ddt_t *ddt, ddt_entry_t *dde, ddt_stat_t *dds)
369 {
370 spa_t *spa = ddt->ddt_spa;
371 ddt_phys_t *ddp = dde->dde_phys;
372 ddt_key_t *ddk = &dde->dde_key;
373 uint64_t lsize = DDK_GET_LSIZE(ddk);
374 uint64_t psize = DDK_GET_PSIZE(ddk);
375
376 bzero(dds, sizeof (*dds));
377
378 for (int p = 0; p < DDT_PHYS_TYPES; p++, ddp++) {
379 uint64_t dsize = 0;
380 uint64_t refcnt = ddp->ddp_refcnt;
381
382 if (ddp->ddp_phys_birth == 0)
383 continue;
384
385 for (int d = 0; d < SPA_DVAS_PER_BP; d++)
386 dsize += dva_get_dsize_sync(spa, &ddp->ddp_dva[d]);
387
388 dds->dds_blocks += 1;
389 dds->dds_lsize += lsize;
390 dds->dds_psize += psize;
391 dds->dds_dsize += dsize;
392
393 dds->dds_ref_blocks += refcnt;
394 dds->dds_ref_lsize += lsize * refcnt;
395 dds->dds_ref_psize += psize * refcnt;
396 dds->dds_ref_dsize += dsize * refcnt;
397 }
398 }
399
400 void
401 ddt_stat_add(ddt_stat_t *dst, const ddt_stat_t *src, uint64_t neg)
402 {
403 const uint64_t *s = (const uint64_t *)src;
404 uint64_t *d = (uint64_t *)dst;
405 uint64_t *d_end = (uint64_t *)(dst + 1);
406
407 ASSERT(neg == 0 || neg == -1ULL); /* add or subtract */
408
409 while (d < d_end)
410 *d++ += (*s++ ^ neg) - neg;
411 }
412
413 static void
414 ddt_stat_update(ddt_t *ddt, ddt_entry_t *dde, uint64_t neg)
415 {
416 ddt_stat_t dds;
417 ddt_histogram_t *ddh;
418 int bucket;
419
420 ddt_stat_generate(ddt, dde, &dds);
421
422 bucket = highbit(dds.dds_ref_blocks) - 1;
423 ASSERT(bucket >= 0);
424
425 ddh = &ddt->ddt_histogram[dde->dde_type][dde->dde_class];
426
427 ddt_stat_add(&ddh->ddh_stat[bucket], &dds, neg);
428 }
429
430 void
431 ddt_histogram_add(ddt_histogram_t *dst, const ddt_histogram_t *src)
432 {
433 for (int h = 0; h < 64; h++)
434 ddt_stat_add(&dst->ddh_stat[h], &src->ddh_stat[h], 0);
435 }
436
437 void
438 ddt_histogram_stat(ddt_stat_t *dds, const ddt_histogram_t *ddh)
439 {
440 bzero(dds, sizeof (*dds));
441
442 for (int h = 0; h < 64; h++)
443 ddt_stat_add(dds, &ddh->ddh_stat[h], 0);
444 }
445
446 boolean_t
447 ddt_histogram_empty(const ddt_histogram_t *ddh)
448 {
449 const uint64_t *s = (const uint64_t *)ddh;
450 const uint64_t *s_end = (const uint64_t *)(ddh + 1);
451
452 while (s < s_end)
453 if (*s++ != 0)
454 return (B_FALSE);
455
456 return (B_TRUE);
457 }
458
459 void
460 ddt_get_dedup_object_stats(spa_t *spa, ddt_object_t *ddo_total)
461 {
462 /* Sum the statistics we cached in ddt_object_sync(). */
463 for (enum zio_checksum c = 0; c < ZIO_CHECKSUM_FUNCTIONS; c++) {
464 ddt_t *ddt = spa->spa_ddt[c];
465 for (enum ddt_type type = 0; type < DDT_TYPES; type++) {
466 for (enum ddt_class class = 0; class < DDT_CLASSES;
467 class++) {
468 ddt_object_t *ddo =
469 &ddt->ddt_object_stats[type][class];
470 ddo_total->ddo_count += ddo->ddo_count;
471 ddo_total->ddo_dspace += ddo->ddo_dspace;
472 ddo_total->ddo_mspace += ddo->ddo_mspace;
473 }
474 }
475 }
476
477 /* ... and compute the averages. */
478 if (ddo_total->ddo_count != 0) {
479 ddo_total->ddo_dspace /= ddo_total->ddo_count;
480 ddo_total->ddo_mspace /= ddo_total->ddo_count;
481 }
482 }
483
484 void
485 ddt_get_dedup_histogram(spa_t *spa, ddt_histogram_t *ddh)
486 {
487 for (enum zio_checksum c = 0; c < ZIO_CHECKSUM_FUNCTIONS; c++) {
488 ddt_t *ddt = spa->spa_ddt[c];
489 for (enum ddt_type type = 0; type < DDT_TYPES; type++) {
490 for (enum ddt_class class = 0; class < DDT_CLASSES;
491 class++) {
492 ddt_histogram_add(ddh,
493 &ddt->ddt_histogram_cache[type][class]);
494 }
495 }
496 }
497 }
498
499 void
500 ddt_get_dedup_stats(spa_t *spa, ddt_stat_t *dds_total)
501 {
502 ddt_histogram_t *ddh_total;
503
504 ddh_total = kmem_zalloc(sizeof (ddt_histogram_t), KM_SLEEP);
505 ddt_get_dedup_histogram(spa, ddh_total);
506 ddt_histogram_stat(dds_total, ddh_total);
507 kmem_free(ddh_total, sizeof (ddt_histogram_t));
508 }
509
510 uint64_t
511 ddt_get_dedup_dspace(spa_t *spa)
512 {
513 ddt_stat_t dds_total = { 0 };
514
515 ddt_get_dedup_stats(spa, &dds_total);
516 return (dds_total.dds_ref_dsize - dds_total.dds_dsize);
517 }
518
519 uint64_t
520 ddt_get_pool_dedup_ratio(spa_t *spa)
521 {
522 ddt_stat_t dds_total = { 0 };
523
524 ddt_get_dedup_stats(spa, &dds_total);
525 if (dds_total.dds_dsize == 0)
526 return (100);
527
528 return (dds_total.dds_ref_dsize * 100 / dds_total.dds_dsize);
529 }
530
531 int
532 ddt_ditto_copies_needed(ddt_t *ddt, ddt_entry_t *dde, ddt_phys_t *ddp_willref)
533 {
534 spa_t *spa = ddt->ddt_spa;
535 uint64_t total_refcnt = 0;
536 uint64_t ditto = spa->spa_dedup_ditto;
537 int total_copies = 0;
538 int desired_copies = 0;
539
540 for (int p = DDT_PHYS_SINGLE; p <= DDT_PHYS_TRIPLE; p++) {
541 ddt_phys_t *ddp = &dde->dde_phys[p];
542 zio_t *zio = dde->dde_lead_zio[p];
543 uint64_t refcnt = ddp->ddp_refcnt; /* committed refs */
544 if (zio != NULL)
545 refcnt += zio->io_parent_count; /* pending refs */
546 if (ddp == ddp_willref)
547 refcnt++; /* caller's ref */
548 if (refcnt != 0) {
549 total_refcnt += refcnt;
550 total_copies += p;
551 }
552 }
553
554 if (ditto == 0 || ditto > UINT32_MAX)
555 ditto = UINT32_MAX;
556
557 if (total_refcnt >= 1)
558 desired_copies++;
559 if (total_refcnt >= ditto)
560 desired_copies++;
561 if (total_refcnt >= ditto * ditto)
562 desired_copies++;
563
564 return (MAX(desired_copies, total_copies) - total_copies);
565 }
566
567 int
568 ddt_ditto_copies_present(ddt_entry_t *dde)
569 {
570 ddt_phys_t *ddp = &dde->dde_phys[DDT_PHYS_DITTO];
571 dva_t *dva = ddp->ddp_dva;
572 int copies = 0 - DVA_GET_GANG(dva);
573
574 for (int d = 0; d < SPA_DVAS_PER_BP; d++, dva++)
575 if (DVA_IS_VALID(dva))
576 copies++;
577
578 ASSERT(copies >= 0 && copies < SPA_DVAS_PER_BP);
579
580 return (copies);
581 }
582
583 size_t
584 ddt_compress(void *src, uchar_t *dst, size_t s_len, size_t d_len)
585 {
586 uchar_t *version = dst++;
587 int cpfunc = ZIO_COMPRESS_ZLE;
588 zio_compress_info_t *ci = &zio_compress_table[cpfunc];
589 size_t c_len;
590
591 ASSERT(d_len >= s_len + 1); /* no compression plus version byte */
592
593 c_len = ci->ci_compress(src, dst, s_len, d_len - 1, ci->ci_level);
594
595 if (c_len == s_len) {
596 cpfunc = ZIO_COMPRESS_OFF;
597 bcopy(src, dst, s_len);
598 }
599
600 *version = (ZFS_HOST_BYTEORDER & DDT_COMPRESS_BYTEORDER_MASK) | cpfunc;
601
602 return (c_len + 1);
603 }
604
605 void
606 ddt_decompress(uchar_t *src, void *dst, size_t s_len, size_t d_len)
607 {
608 uchar_t version = *src++;
609 int cpfunc = version & DDT_COMPRESS_FUNCTION_MASK;
610 zio_compress_info_t *ci = &zio_compress_table[cpfunc];
611
612 if (ci->ci_decompress != NULL)
613 (void) ci->ci_decompress(src, dst, s_len, d_len, ci->ci_level);
614 else
615 bcopy(src, dst, d_len);
616
617 if ((version ^ ZFS_HOST_BYTEORDER) & DDT_COMPRESS_BYTEORDER_MASK)
618 byteswap_uint64_array(dst, d_len);
619 }
620
621 ddt_t *
622 ddt_select_by_checksum(spa_t *spa, enum zio_checksum c)
623 {
624 return (spa->spa_ddt[c]);
625 }
626
627 ddt_t *
628 ddt_select(spa_t *spa, const blkptr_t *bp)
629 {
630 return (spa->spa_ddt[BP_GET_CHECKSUM(bp)]);
631 }
632
633 void
634 ddt_enter(ddt_t *ddt)
635 {
636 mutex_enter(&ddt->ddt_lock);
637 }
638
639 void
640 ddt_exit(ddt_t *ddt)
641 {
642 mutex_exit(&ddt->ddt_lock);
643 }
644
645 static ddt_entry_t *
646 ddt_alloc(const ddt_key_t *ddk)
647 {
648 ddt_entry_t *dde;
649
650 dde = kmem_zalloc(sizeof (ddt_entry_t), KM_SLEEP);
651 cv_init(&dde->dde_cv, NULL, CV_DEFAULT, NULL);
652
653 dde->dde_key = *ddk;
654
655 return (dde);
656 }
657
658 static void
659 ddt_free(ddt_entry_t *dde)
660 {
661 ASSERT(!dde->dde_loading);
662
663 for (int p = 0; p < DDT_PHYS_TYPES; p++)
664 ASSERT(dde->dde_lead_zio[p] == NULL);
665
666 if (dde->dde_repair_data != NULL)
667 zio_buf_free(dde->dde_repair_data,
668 DDK_GET_PSIZE(&dde->dde_key));
669
670 cv_destroy(&dde->dde_cv);
671 kmem_free(dde, sizeof (*dde));
672 }
673
674 void
675 ddt_remove(ddt_t *ddt, ddt_entry_t *dde)
676 {
677 ASSERT(MUTEX_HELD(&ddt->ddt_lock));
678
679 avl_remove(&ddt->ddt_tree, dde);
680 ddt_free(dde);
681 }
682
683 ddt_entry_t *
684 ddt_lookup(ddt_t *ddt, const blkptr_t *bp, boolean_t add)
685 {
686 ddt_entry_t *dde, dde_search;
687 enum ddt_type type;
688 enum ddt_class class;
689 avl_index_t where;
690 int error;
691
692 ASSERT(MUTEX_HELD(&ddt->ddt_lock));
693
694 ddt_key_fill(&dde_search.dde_key, bp);
695
696 dde = avl_find(&ddt->ddt_tree, &dde_search, &where);
697 if (dde == NULL) {
698 if (!add)
699 return (NULL);
700 dde = ddt_alloc(&dde_search.dde_key);
701 avl_insert(&ddt->ddt_tree, dde, where);
702 }
703
704 while (dde->dde_loading)
705 cv_wait(&dde->dde_cv, &ddt->ddt_lock);
706
707 if (dde->dde_loaded)
708 return (dde);
709
710 dde->dde_loading = B_TRUE;
711
712 ddt_exit(ddt);
713
714 error = ENOENT;
715
716 for (type = 0; type < DDT_TYPES; type++) {
717 for (class = 0; class < DDT_CLASSES; class++) {
718 error = ddt_object_lookup(ddt, type, class, dde);
719 if (error != ENOENT)
720 break;
721 }
722 if (error != ENOENT)
723 break;
724 }
725
726 ASSERT(error == 0 || error == ENOENT);
727
728 ddt_enter(ddt);
729
730 ASSERT(dde->dde_loaded == B_FALSE);
731 ASSERT(dde->dde_loading == B_TRUE);
732
733 dde->dde_type = type; /* will be DDT_TYPES if no entry found */
734 dde->dde_class = class; /* will be DDT_CLASSES if no entry found */
735 dde->dde_loaded = B_TRUE;
736 dde->dde_loading = B_FALSE;
737
738 if (error == 0)
739 ddt_stat_update(ddt, dde, -1ULL);
740
741 cv_broadcast(&dde->dde_cv);
742
743 return (dde);
744 }
745
746 void
747 ddt_prefetch(spa_t *spa, const blkptr_t *bp)
748 {
749 ddt_t *ddt;
750 ddt_entry_t dde;
751
752 if (!zfs_dedup_prefetch || bp == NULL || !BP_GET_DEDUP(bp))
753 return;
754
755 /*
756 * We only remove the DDT once all tables are empty and only
757 * prefetch dedup blocks when there are entries in the DDT.
758 * Thus no locking is required as the DDT can't disappear on us.
759 */
760 ddt = ddt_select(spa, bp);
761 ddt_key_fill(&dde.dde_key, bp);
762
763 for (enum ddt_type type = 0; type < DDT_TYPES; type++) {
764 for (enum ddt_class class = 0; class < DDT_CLASSES; class++) {
765 ddt_object_prefetch(ddt, type, class, &dde);
766 }
767 }
768 }
769
770 int
771 ddt_entry_compare(const void *x1, const void *x2)
772 {
773 const ddt_entry_t *dde1 = x1;
774 const ddt_entry_t *dde2 = x2;
775 const uint64_t *u1 = (const uint64_t *)&dde1->dde_key;
776 const uint64_t *u2 = (const uint64_t *)&dde2->dde_key;
777
778 for (int i = 0; i < DDT_KEY_WORDS; i++) {
779 if (u1[i] < u2[i])
780 return (-1);
781 if (u1[i] > u2[i])
782 return (1);
783 }
784
785 return (0);
786 }
787
788 static ddt_t *
789 ddt_table_alloc(spa_t *spa, enum zio_checksum c)
790 {
791 ddt_t *ddt;
792
793 ddt = kmem_zalloc(sizeof (*ddt), KM_SLEEP);
794
795 mutex_init(&ddt->ddt_lock, NULL, MUTEX_DEFAULT, NULL);
796 avl_create(&ddt->ddt_tree, ddt_entry_compare,
797 sizeof (ddt_entry_t), offsetof(ddt_entry_t, dde_node));
798 avl_create(&ddt->ddt_repair_tree, ddt_entry_compare,
799 sizeof (ddt_entry_t), offsetof(ddt_entry_t, dde_node));
800 ddt->ddt_checksum = c;
801 ddt->ddt_spa = spa;
802 ddt->ddt_os = spa->spa_meta_objset;
803
804 return (ddt);
805 }
806
807 static void
808 ddt_table_free(ddt_t *ddt)
809 {
810 ASSERT(avl_numnodes(&ddt->ddt_tree) == 0);
811 ASSERT(avl_numnodes(&ddt->ddt_repair_tree) == 0);
812 avl_destroy(&ddt->ddt_tree);
813 avl_destroy(&ddt->ddt_repair_tree);
814 mutex_destroy(&ddt->ddt_lock);
815 kmem_free(ddt, sizeof (*ddt));
816 }
817
818 void
819 ddt_create(spa_t *spa)
820 {
821 spa->spa_dedup_checksum = ZIO_DEDUPCHECKSUM;
822
823 for (enum zio_checksum c = 0; c < ZIO_CHECKSUM_FUNCTIONS; c++)
824 spa->spa_ddt[c] = ddt_table_alloc(spa, c);
825 }
826
827 int
828 ddt_load(spa_t *spa)
829 {
830 int error;
831
832 ddt_create(spa);
833
834 error = zap_lookup(spa->spa_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
835 DMU_POOL_DDT_STATS, sizeof (uint64_t), 1,
836 &spa->spa_ddt_stat_object);
837
838 if (error)
839 return (error == ENOENT ? 0 : error);
840
841 for (enum zio_checksum c = 0; c < ZIO_CHECKSUM_FUNCTIONS; c++) {
842 ddt_t *ddt = spa->spa_ddt[c];
843 for (enum ddt_type type = 0; type < DDT_TYPES; type++) {
844 for (enum ddt_class class = 0; class < DDT_CLASSES;
845 class++) {
846 error = ddt_object_load(ddt, type, class);
847 if (error != 0 && error != ENOENT)
848 return (error);
849 }
850 }
851
852 /*
853 * Seed the cached histograms.
854 */
855 bcopy(ddt->ddt_histogram, &ddt->ddt_histogram_cache,
856 sizeof (ddt->ddt_histogram));
857 }
858
859 return (0);
860 }
861
862 void
863 ddt_unload(spa_t *spa)
864 {
865 for (enum zio_checksum c = 0; c < ZIO_CHECKSUM_FUNCTIONS; c++) {
866 if (spa->spa_ddt[c]) {
867 ddt_table_free(spa->spa_ddt[c]);
868 spa->spa_ddt[c] = NULL;
869 }
870 }
871 }
872
873 boolean_t
874 ddt_class_contains(spa_t *spa, enum ddt_class max_class, const blkptr_t *bp)
875 {
876 ddt_t *ddt;
877 ddt_entry_t dde;
878
879 if (!BP_GET_DEDUP(bp))
880 return (B_FALSE);
881
882 if (max_class == DDT_CLASS_UNIQUE)
883 return (B_TRUE);
884
885 ddt = spa->spa_ddt[BP_GET_CHECKSUM(bp)];
886
887 ddt_key_fill(&dde.dde_key, bp);
888
889 for (enum ddt_type type = 0; type < DDT_TYPES; type++)
890 for (enum ddt_class class = 0; class <= max_class; class++)
891 if (ddt_object_lookup(ddt, type, class, &dde) == 0)
892 return (B_TRUE);
893
894 return (B_FALSE);
895 }
896
897 ddt_entry_t *
898 ddt_repair_start(ddt_t *ddt, const blkptr_t *bp)
899 {
900 ddt_key_t ddk;
901 ddt_entry_t *dde;
902
903 ddt_key_fill(&ddk, bp);
904
905 dde = ddt_alloc(&ddk);
906
907 for (enum ddt_type type = 0; type < DDT_TYPES; type++) {
908 for (enum ddt_class class = 0; class < DDT_CLASSES; class++) {
909 /*
910 * We can only do repair if there are multiple copies
911 * of the block. For anything in the UNIQUE class,
912 * there's definitely only one copy, so don't even try.
913 */
914 if (class != DDT_CLASS_UNIQUE &&
915 ddt_object_lookup(ddt, type, class, dde) == 0)
916 return (dde);
917 }
918 }
919
920 bzero(dde->dde_phys, sizeof (dde->dde_phys));
921
922 return (dde);
923 }
924
925 void
926 ddt_repair_done(ddt_t *ddt, ddt_entry_t *dde)
927 {
928 avl_index_t where;
929
930 ddt_enter(ddt);
931
932 if (dde->dde_repair_data != NULL && spa_writeable(ddt->ddt_spa) &&
933 avl_find(&ddt->ddt_repair_tree, dde, &where) == NULL)
934 avl_insert(&ddt->ddt_repair_tree, dde, where);
935 else
936 ddt_free(dde);
937
938 ddt_exit(ddt);
939 }
940
941 static void
942 ddt_repair_entry_done(zio_t *zio)
943 {
944 ddt_entry_t *rdde = zio->io_private;
945
946 ddt_free(rdde);
947 }
948
949 static void
950 ddt_repair_entry(ddt_t *ddt, ddt_entry_t *dde, ddt_entry_t *rdde, zio_t *rio)
951 {
952 ddt_phys_t *ddp = dde->dde_phys;
953 ddt_phys_t *rddp = rdde->dde_phys;
954 ddt_key_t *ddk = &dde->dde_key;
955 ddt_key_t *rddk = &rdde->dde_key;
956 zio_t *zio;
957 blkptr_t blk;
958
959 zio = zio_null(rio, rio->io_spa, NULL,
960 ddt_repair_entry_done, rdde, rio->io_flags);
961
962 for (int p = 0; p < DDT_PHYS_TYPES; p++, ddp++, rddp++) {
963 if (ddp->ddp_phys_birth == 0 ||
964 ddp->ddp_phys_birth != rddp->ddp_phys_birth ||
965 bcmp(ddp->ddp_dva, rddp->ddp_dva, sizeof (ddp->ddp_dva)))
966 continue;
967 ddt_bp_create(ddt->ddt_checksum, ddk, ddp, &blk);
968 zio_nowait(zio_rewrite(zio, zio->io_spa, 0, &blk,
969 rdde->dde_repair_data, DDK_GET_PSIZE(rddk), NULL, NULL,
970 ZIO_PRIORITY_SYNC_WRITE, ZIO_DDT_CHILD_FLAGS(zio), NULL));
971 }
972
973 zio_nowait(zio);
974 }
975
976 static void
977 ddt_repair_table(ddt_t *ddt, zio_t *rio)
978 {
979 spa_t *spa = ddt->ddt_spa;
980 ddt_entry_t *dde, *rdde_next, *rdde;
981 avl_tree_t *t = &ddt->ddt_repair_tree;
982 blkptr_t blk;
983
984 if (spa_sync_pass(spa) > 1)
985 return;
986
987 ddt_enter(ddt);
988 for (rdde = avl_first(t); rdde != NULL; rdde = rdde_next) {
989 rdde_next = AVL_NEXT(t, rdde);
990 avl_remove(&ddt->ddt_repair_tree, rdde);
991 ddt_exit(ddt);
992 ddt_bp_create(ddt->ddt_checksum, &rdde->dde_key, NULL, &blk);
993 dde = ddt_repair_start(ddt, &blk);
994 ddt_repair_entry(ddt, dde, rdde, rio);
995 ddt_repair_done(ddt, dde);
996 ddt_enter(ddt);
997 }
998 ddt_exit(ddt);
999 }
1000
1001 static void
1002 ddt_sync_entry(ddt_t *ddt, ddt_entry_t *dde, dmu_tx_t *tx, uint64_t txg)
1003 {
1004 dsl_pool_t *dp = ddt->ddt_spa->spa_dsl_pool;
1005 ddt_phys_t *ddp = dde->dde_phys;
1006 ddt_key_t *ddk = &dde->dde_key;
1007 enum ddt_type otype = dde->dde_type;
1008 enum ddt_type ntype = DDT_TYPE_CURRENT;
1009 enum ddt_class oclass = dde->dde_class;
1010 enum ddt_class nclass;
1011 uint64_t total_refcnt = 0;
1012
1013 ASSERT(dde->dde_loaded);
1014 ASSERT(!dde->dde_loading);
1015
1016 for (int p = 0; p < DDT_PHYS_TYPES; p++, ddp++) {
1017 ASSERT(dde->dde_lead_zio[p] == NULL);
1018 ASSERT((int64_t)ddp->ddp_refcnt >= 0);
1019 if (ddp->ddp_phys_birth == 0) {
1020 ASSERT(ddp->ddp_refcnt == 0);
1021 continue;
1022 }
1023 if (p == DDT_PHYS_DITTO) {
1024 if (ddt_ditto_copies_needed(ddt, dde, NULL) == 0)
1025 ddt_phys_free(ddt, ddk, ddp, txg);
1026 continue;
1027 }
1028 if (ddp->ddp_refcnt == 0)
1029 ddt_phys_free(ddt, ddk, ddp, txg);
1030 total_refcnt += ddp->ddp_refcnt;
1031 }
1032
1033 if (dde->dde_phys[DDT_PHYS_DITTO].ddp_phys_birth != 0)
1034 nclass = DDT_CLASS_DITTO;
1035 else if (total_refcnt > 1)
1036 nclass = DDT_CLASS_DUPLICATE;
1037 else
1038 nclass = DDT_CLASS_UNIQUE;
1039
1040 if (otype != DDT_TYPES &&
1041 (otype != ntype || oclass != nclass || total_refcnt == 0)) {
1042 VERIFY(ddt_object_remove(ddt, otype, oclass, dde, tx) == 0);
1043 ASSERT(ddt_object_lookup(ddt, otype, oclass, dde) == ENOENT);
1044 }
1045
1046 if (total_refcnt != 0) {
1047 dde->dde_type = ntype;
1048 dde->dde_class = nclass;
1049 ddt_stat_update(ddt, dde, 0);
1050 if (!ddt_object_exists(ddt, ntype, nclass))
1051 ddt_object_create(ddt, ntype, nclass, tx);
1052 VERIFY(ddt_object_update(ddt, ntype, nclass, dde, tx) == 0);
1053
1054 /*
1055 * If the class changes, the order that we scan this bp
1056 * changes. If it decreases, we could miss it, so
1057 * scan it right now. (This covers both class changing
1058 * while we are doing ddt_walk(), and when we are
1059 * traversing.)
1060 */
1061 if (nclass < oclass) {
1062 dsl_scan_ddt_entry(dp->dp_scan,
1063 ddt->ddt_checksum, dde, tx);
1064 }
1065 }
1066 }
1067
1068 static void
1069 ddt_sync_table(ddt_t *ddt, dmu_tx_t *tx, uint64_t txg)
1070 {
1071 spa_t *spa = ddt->ddt_spa;
1072 ddt_entry_t *dde;
1073 void *cookie = NULL;
1074
1075 if (avl_numnodes(&ddt->ddt_tree) == 0)
1076 return;
1077
1078 ASSERT(spa->spa_uberblock.ub_version >= SPA_VERSION_DEDUP);
1079
1080 if (spa->spa_ddt_stat_object == 0) {
1081 spa->spa_ddt_stat_object = zap_create(ddt->ddt_os,
1082 DMU_OT_DDT_STATS, DMU_OT_NONE, 0, tx);
1083 VERIFY(zap_add(ddt->ddt_os, DMU_POOL_DIRECTORY_OBJECT,
1084 DMU_POOL_DDT_STATS, sizeof (uint64_t), 1,
1085 &spa->spa_ddt_stat_object, tx) == 0);
1086 }
1087
1088 while ((dde = avl_destroy_nodes(&ddt->ddt_tree, &cookie)) != NULL) {
1089 ddt_sync_entry(ddt, dde, tx, txg);
1090 ddt_free(dde);
1091 }
1092
1093 for (enum ddt_type type = 0; type < DDT_TYPES; type++) {
1094 uint64_t count = 0;
1095 for (enum ddt_class class = 0; class < DDT_CLASSES; class++) {
1096 if (ddt_object_exists(ddt, type, class)) {
1097 ddt_object_sync(ddt, type, class, tx);
1098 count += ddt_object_count(ddt, type, class);
1099 }
1100 }
1101 for (enum ddt_class class = 0; class < DDT_CLASSES; class++) {
1102 if (count == 0 && ddt_object_exists(ddt, type, class))
1103 ddt_object_destroy(ddt, type, class, tx);
1104 }
1105 }
1106
1107 bcopy(ddt->ddt_histogram, &ddt->ddt_histogram_cache,
1108 sizeof (ddt->ddt_histogram));
1109 }
1110
1111 void
1112 ddt_sync(spa_t *spa, uint64_t txg)
1113 {
1114 dmu_tx_t *tx;
1115 zio_t *rio = zio_root(spa, NULL, NULL,
1116 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE);
1117
1118 ASSERT(spa_syncing_txg(spa) == txg);
1119
1120 tx = dmu_tx_create_assigned(spa->spa_dsl_pool, txg);
1121
1122 for (enum zio_checksum c = 0; c < ZIO_CHECKSUM_FUNCTIONS; c++) {
1123 ddt_t *ddt = spa->spa_ddt[c];
1124 if (ddt == NULL)
1125 continue;
1126 ddt_sync_table(ddt, tx, txg);
1127 ddt_repair_table(ddt, rio);
1128 }
1129
1130 (void) zio_wait(rio);
1131
1132 dmu_tx_commit(tx);
1133 }
1134
1135 int
1136 ddt_walk(spa_t *spa, ddt_bookmark_t *ddb, ddt_entry_t *dde)
1137 {
1138 do {
1139 do {
1140 do {
1141 ddt_t *ddt = spa->spa_ddt[ddb->ddb_checksum];
1142 int error = ENOENT;
1143 if (ddt_object_exists(ddt, ddb->ddb_type,
1144 ddb->ddb_class)) {
1145 error = ddt_object_walk(ddt,
1146 ddb->ddb_type, ddb->ddb_class,
1147 &ddb->ddb_cursor, dde);
1148 }
1149 dde->dde_type = ddb->ddb_type;
1150 dde->dde_class = ddb->ddb_class;
1151 if (error == 0)
1152 return (0);
1153 if (error != ENOENT)
1154 return (error);
1155 ddb->ddb_cursor = 0;
1156 } while (++ddb->ddb_checksum < ZIO_CHECKSUM_FUNCTIONS);
1157 ddb->ddb_checksum = 0;
1158 } while (++ddb->ddb_type < DDT_TYPES);
1159 ddb->ddb_type = 0;
1160 } while (++ddb->ddb_class < DDT_CLASSES);
1161
1162 return (ENOENT);
1163 }