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->ddp_phys_birth == 0);
291
292 for (int d = 0; d < SPA_DVAS_PER_BP; d++)
293 ddp->ddp_dva[d] = bp->blk_dva[d];
294 ddp->ddp_phys_birth = BP_PHYSICAL_BIRTH(bp);
295 }
296
297 void
298 ddt_phys_clear(ddt_phys_t *ddp)
299 {
300 bzero(ddp, sizeof (*ddp));
301 }
302
303 void
304 ddt_phys_addref(ddt_phys_t *ddp)
305 {
306 ddp->ddp_refcnt++;
307 }
308
309 void
310 ddt_phys_decref(ddt_phys_t *ddp)
311 {
312 ASSERT((int64_t)ddp->ddp_refcnt > 0);
313 ddp->ddp_refcnt--;
314 }
315
316 void
317 ddt_phys_free(ddt_t *ddt, ddt_key_t *ddk, ddt_phys_t *ddp, uint64_t txg)
318 {
319 blkptr_t blk;
320
321 ddt_bp_create(ddt->ddt_checksum, ddk, ddp, &blk);
322 ddt_phys_clear(ddp);
323 zio_free(ddt->ddt_spa, txg, &blk);
324 }
325
326 ddt_phys_t *
327 ddt_phys_select(const ddt_entry_t *dde, const blkptr_t *bp)
328 {
329 ddt_phys_t *ddp = (ddt_phys_t *)dde->dde_phys;
330
331 for (int p = 0; p < DDT_PHYS_TYPES; p++, ddp++) {
332 if (DVA_EQUAL(BP_IDENTITY(bp), &ddp->ddp_dva[0]) &&
333 BP_PHYSICAL_BIRTH(bp) == ddp->ddp_phys_birth)
334 return (ddp);
335 }
336 return (NULL);
337 }
338
339 uint64_t
340 ddt_phys_total_refcnt(const ddt_entry_t *dde)
341 {
342 uint64_t refcnt = 0;
343
344 for (int p = DDT_PHYS_SINGLE; p <= DDT_PHYS_TRIPLE; p++)
345 refcnt += dde->dde_phys[p].ddp_refcnt;
346
347 return (refcnt);
348 }
349
350 static void
351 ddt_stat_generate(ddt_t *ddt, ddt_entry_t *dde, ddt_stat_t *dds)
352 {
353 spa_t *spa = ddt->ddt_spa;
354 ddt_phys_t *ddp = dde->dde_phys;
355 ddt_key_t *ddk = &dde->dde_key;
356 uint64_t lsize = DDK_GET_LSIZE(ddk);
357 uint64_t psize = DDK_GET_PSIZE(ddk);
358
359 bzero(dds, sizeof (*dds));
360
361 for (int p = 0; p < DDT_PHYS_TYPES; p++, ddp++) {
362 uint64_t dsize = 0;
363 uint64_t refcnt = ddp->ddp_refcnt;
364
365 if (ddp->ddp_phys_birth == 0)
366 continue;
367
368 for (int d = 0; d < SPA_DVAS_PER_BP; d++)
369 dsize += dva_get_dsize_sync(spa, &ddp->ddp_dva[d]);
370
371 dds->dds_blocks += 1;
372 dds->dds_lsize += lsize;
373 dds->dds_psize += psize;
374 dds->dds_dsize += dsize;
375
376 dds->dds_ref_blocks += refcnt;
377 dds->dds_ref_lsize += lsize * refcnt;
378 dds->dds_ref_psize += psize * refcnt;
379 dds->dds_ref_dsize += dsize * refcnt;
380 }
381 }
382
383 void
384 ddt_stat_add(ddt_stat_t *dst, const ddt_stat_t *src, uint64_t neg)
385 {
386 const uint64_t *s = (const uint64_t *)src;
387 uint64_t *d = (uint64_t *)dst;
388 uint64_t *d_end = (uint64_t *)(dst + 1);
389
390 ASSERT(neg == 0 || neg == -1ULL); /* add or subtract */
391
392 while (d < d_end)
393 *d++ += (*s++ ^ neg) - neg;
394 }
395
396 static void
397 ddt_stat_update(ddt_t *ddt, ddt_entry_t *dde, uint64_t neg)
398 {
399 ddt_stat_t dds;
400 ddt_histogram_t *ddh;
401 int bucket;
402
403 ddt_stat_generate(ddt, dde, &dds);
404
405 bucket = highbit(dds.dds_ref_blocks) - 1;
406 ASSERT(bucket >= 0);
407
408 ddh = &ddt->ddt_histogram[dde->dde_type][dde->dde_class];
409
410 ddt_stat_add(&ddh->ddh_stat[bucket], &dds, neg);
411 }
412
413 void
414 ddt_histogram_add(ddt_histogram_t *dst, const ddt_histogram_t *src)
415 {
416 for (int h = 0; h < 64; h++)
417 ddt_stat_add(&dst->ddh_stat[h], &src->ddh_stat[h], 0);
418 }
419
420 void
421 ddt_histogram_stat(ddt_stat_t *dds, const ddt_histogram_t *ddh)
422 {
423 bzero(dds, sizeof (*dds));
424
425 for (int h = 0; h < 64; h++)
426 ddt_stat_add(dds, &ddh->ddh_stat[h], 0);
427 }
428
429 boolean_t
430 ddt_histogram_empty(const ddt_histogram_t *ddh)
431 {
432 const uint64_t *s = (const uint64_t *)ddh;
433 const uint64_t *s_end = (const uint64_t *)(ddh + 1);
434
435 while (s < s_end)
436 if (*s++ != 0)
437 return (B_FALSE);
438
439 return (B_TRUE);
440 }
441
442 void
443 ddt_get_dedup_object_stats(spa_t *spa, ddt_object_t *ddo_total)
444 {
445 /* Sum the statistics we cached in ddt_object_sync(). */
446 for (enum zio_checksum c = 0; c < ZIO_CHECKSUM_FUNCTIONS; c++) {
447 ddt_t *ddt = spa->spa_ddt[c];
448 for (enum ddt_type type = 0; type < DDT_TYPES; type++) {
449 for (enum ddt_class class = 0; class < DDT_CLASSES;
450 class++) {
451 ddt_object_t *ddo =
452 &ddt->ddt_object_stats[type][class];
453 ddo_total->ddo_count += ddo->ddo_count;
454 ddo_total->ddo_dspace += ddo->ddo_dspace;
455 ddo_total->ddo_mspace += ddo->ddo_mspace;
456 }
457 }
458 }
459
460 /* ... and compute the averages. */
461 if (ddo_total->ddo_count != 0) {
462 ddo_total->ddo_dspace /= ddo_total->ddo_count;
463 ddo_total->ddo_mspace /= ddo_total->ddo_count;
464 }
465 }
466
467 void
468 ddt_get_dedup_histogram(spa_t *spa, ddt_histogram_t *ddh)
469 {
470 for (enum zio_checksum c = 0; c < ZIO_CHECKSUM_FUNCTIONS; c++) {
471 ddt_t *ddt = spa->spa_ddt[c];
472 for (enum ddt_type type = 0; type < DDT_TYPES; type++) {
473 for (enum ddt_class class = 0; class < DDT_CLASSES;
474 class++) {
475 ddt_histogram_add(ddh,
476 &ddt->ddt_histogram_cache[type][class]);
477 }
478 }
479 }
480 }
481
482 void
483 ddt_get_dedup_stats(spa_t *spa, ddt_stat_t *dds_total)
484 {
485 ddt_histogram_t *ddh_total;
486
487 ddh_total = kmem_zalloc(sizeof (ddt_histogram_t), KM_SLEEP);
488 ddt_get_dedup_histogram(spa, ddh_total);
489 ddt_histogram_stat(dds_total, ddh_total);
490 kmem_free(ddh_total, sizeof (ddt_histogram_t));
491 }
492
493 uint64_t
494 ddt_get_dedup_dspace(spa_t *spa)
495 {
496 ddt_stat_t dds_total = { 0 };
497
498 ddt_get_dedup_stats(spa, &dds_total);
499 return (dds_total.dds_ref_dsize - dds_total.dds_dsize);
500 }
501
502 uint64_t
503 ddt_get_pool_dedup_ratio(spa_t *spa)
504 {
505 ddt_stat_t dds_total = { 0 };
506
507 ddt_get_dedup_stats(spa, &dds_total);
508 if (dds_total.dds_dsize == 0)
509 return (100);
510
511 return (dds_total.dds_ref_dsize * 100 / dds_total.dds_dsize);
512 }
513
514 int
515 ddt_ditto_copies_needed(ddt_t *ddt, ddt_entry_t *dde, ddt_phys_t *ddp_willref)
516 {
517 spa_t *spa = ddt->ddt_spa;
518 uint64_t total_refcnt = 0;
519 uint64_t ditto = spa->spa_dedup_ditto;
520 int total_copies = 0;
521 int desired_copies = 0;
522
523 for (int p = DDT_PHYS_SINGLE; p <= DDT_PHYS_TRIPLE; p++) {
524 ddt_phys_t *ddp = &dde->dde_phys[p];
525 zio_t *zio = dde->dde_lead_zio[p];
526 uint64_t refcnt = ddp->ddp_refcnt; /* committed refs */
527 if (zio != NULL)
528 refcnt += zio->io_parent_count; /* pending refs */
529 if (ddp == ddp_willref)
530 refcnt++; /* caller's ref */
531 if (refcnt != 0) {
532 total_refcnt += refcnt;
533 total_copies += p;
534 }
535 }
536
537 if (ditto == 0 || ditto > UINT32_MAX)
538 ditto = UINT32_MAX;
539
540 if (total_refcnt >= 1)
541 desired_copies++;
542 if (total_refcnt >= ditto)
543 desired_copies++;
544 if (total_refcnt >= ditto * ditto)
545 desired_copies++;
546
547 return (MAX(desired_copies, total_copies) - total_copies);
548 }
549
550 int
551 ddt_ditto_copies_present(ddt_entry_t *dde)
552 {
553 ddt_phys_t *ddp = &dde->dde_phys[DDT_PHYS_DITTO];
554 dva_t *dva = ddp->ddp_dva;
555 int copies = 0 - DVA_GET_GANG(dva);
556
557 for (int d = 0; d < SPA_DVAS_PER_BP; d++, dva++)
558 if (DVA_IS_VALID(dva))
559 copies++;
560
561 ASSERT(copies >= 0 && copies < SPA_DVAS_PER_BP);
562
563 return (copies);
564 }
565
566 size_t
567 ddt_compress(void *src, uchar_t *dst, size_t s_len, size_t d_len)
568 {
569 uchar_t *version = dst++;
570 int cpfunc = ZIO_COMPRESS_ZLE;
571 zio_compress_info_t *ci = &zio_compress_table[cpfunc];
572 size_t c_len;
573
574 ASSERT(d_len >= s_len + 1); /* no compression plus version byte */
575
576 c_len = ci->ci_compress(src, dst, s_len, d_len - 1, ci->ci_level);
577
578 if (c_len == s_len) {
579 cpfunc = ZIO_COMPRESS_OFF;
580 bcopy(src, dst, s_len);
581 }
582
583 *version = (ZFS_HOST_BYTEORDER & DDT_COMPRESS_BYTEORDER_MASK) | cpfunc;
584
585 return (c_len + 1);
586 }
587
588 void
589 ddt_decompress(uchar_t *src, void *dst, size_t s_len, size_t d_len)
590 {
591 uchar_t version = *src++;
592 int cpfunc = version & DDT_COMPRESS_FUNCTION_MASK;
593 zio_compress_info_t *ci = &zio_compress_table[cpfunc];
594
595 if (ci->ci_decompress != NULL)
596 (void) ci->ci_decompress(src, dst, s_len, d_len, ci->ci_level);
597 else
598 bcopy(src, dst, d_len);
599
600 if ((version ^ ZFS_HOST_BYTEORDER) & DDT_COMPRESS_BYTEORDER_MASK)
601 byteswap_uint64_array(dst, d_len);
602 }
603
604 ddt_t *
605 ddt_select_by_checksum(spa_t *spa, enum zio_checksum c)
606 {
607 return (spa->spa_ddt[c]);
608 }
609
610 ddt_t *
611 ddt_select(spa_t *spa, const blkptr_t *bp)
612 {
613 return (spa->spa_ddt[BP_GET_CHECKSUM(bp)]);
614 }
615
616 void
617 ddt_enter(ddt_t *ddt)
618 {
619 mutex_enter(&ddt->ddt_lock);
620 }
621
622 void
623 ddt_exit(ddt_t *ddt)
624 {
625 mutex_exit(&ddt->ddt_lock);
626 }
627
628 static ddt_entry_t *
629 ddt_alloc(const ddt_key_t *ddk)
630 {
631 ddt_entry_t *dde;
632
633 dde = kmem_zalloc(sizeof (ddt_entry_t), KM_SLEEP);
634 cv_init(&dde->dde_cv, NULL, CV_DEFAULT, NULL);
635
636 dde->dde_key = *ddk;
637
638 return (dde);
639 }
640
641 static void
642 ddt_free(ddt_entry_t *dde)
643 {
644 ASSERT(!dde->dde_loading);
645
646 for (int p = 0; p < DDT_PHYS_TYPES; p++)
647 ASSERT(dde->dde_lead_zio[p] == NULL);
648
649 if (dde->dde_repair_data != NULL)
650 zio_buf_free(dde->dde_repair_data,
651 DDK_GET_PSIZE(&dde->dde_key));
652
653 cv_destroy(&dde->dde_cv);
654 kmem_free(dde, sizeof (*dde));
655 }
656
657 void
658 ddt_remove(ddt_t *ddt, ddt_entry_t *dde)
659 {
660 ASSERT(MUTEX_HELD(&ddt->ddt_lock));
661
662 avl_remove(&ddt->ddt_tree, dde);
663 ddt_free(dde);
664 }
665
666 ddt_entry_t *
667 ddt_lookup(ddt_t *ddt, const blkptr_t *bp, boolean_t add)
668 {
669 ddt_entry_t *dde, dde_search;
670 enum ddt_type type;
671 enum ddt_class class;
672 avl_index_t where;
673 int error;
674
675 ASSERT(MUTEX_HELD(&ddt->ddt_lock));
676
677 ddt_key_fill(&dde_search.dde_key, bp);
678
679 dde = avl_find(&ddt->ddt_tree, &dde_search, &where);
680 if (dde == NULL) {
681 if (!add)
682 return (NULL);
683 dde = ddt_alloc(&dde_search.dde_key);
684 avl_insert(&ddt->ddt_tree, dde, where);
685 }
686
687 while (dde->dde_loading)
688 cv_wait(&dde->dde_cv, &ddt->ddt_lock);
689
690 if (dde->dde_loaded)
691 return (dde);
692
693 dde->dde_loading = B_TRUE;
694
695 ddt_exit(ddt);
696
697 error = ENOENT;
698
699 for (type = 0; type < DDT_TYPES; type++) {
700 for (class = 0; class < DDT_CLASSES; class++) {
701 error = ddt_object_lookup(ddt, type, class, dde);
702 if (error != ENOENT)
703 break;
704 }
705 if (error != ENOENT)
706 break;
707 }
708
709 ASSERT(error == 0 || error == ENOENT);
710
711 ddt_enter(ddt);
712
713 ASSERT(dde->dde_loaded == B_FALSE);
714 ASSERT(dde->dde_loading == B_TRUE);
715
716 dde->dde_type = type; /* will be DDT_TYPES if no entry found */
717 dde->dde_class = class; /* will be DDT_CLASSES if no entry found */
718 dde->dde_loaded = B_TRUE;
719 dde->dde_loading = B_FALSE;
720
721 if (error == 0)
722 ddt_stat_update(ddt, dde, -1ULL);
723
724 cv_broadcast(&dde->dde_cv);
725
726 return (dde);
727 }
728
729 void
730 ddt_prefetch(spa_t *spa, const blkptr_t *bp)
731 {
732 ddt_t *ddt;
733 ddt_entry_t dde;
734
735 if (!zfs_dedup_prefetch || bp == NULL || !BP_GET_DEDUP(bp))
736 return;
737
738 /*
739 * We only remove the DDT once all tables are empty and only
740 * prefetch dedup blocks when there are entries in the DDT.
741 * Thus no locking is required as the DDT can't disappear on us.
742 */
743 ddt = ddt_select(spa, bp);
744 ddt_key_fill(&dde.dde_key, bp);
745
746 for (enum ddt_type type = 0; type < DDT_TYPES; type++) {
747 for (enum ddt_class class = 0; class < DDT_CLASSES; class++) {
748 ddt_object_prefetch(ddt, type, class, &dde);
749 }
750 }
751 }
752
753 int
754 ddt_entry_compare(const void *x1, const void *x2)
755 {
756 const ddt_entry_t *dde1 = x1;
757 const ddt_entry_t *dde2 = x2;
758 const uint64_t *u1 = (const uint64_t *)&dde1->dde_key;
759 const uint64_t *u2 = (const uint64_t *)&dde2->dde_key;
760
761 for (int i = 0; i < DDT_KEY_WORDS; i++) {
762 if (u1[i] < u2[i])
763 return (-1);
764 if (u1[i] > u2[i])
765 return (1);
766 }
767
768 return (0);
769 }
770
771 static ddt_t *
772 ddt_table_alloc(spa_t *spa, enum zio_checksum c)
773 {
774 ddt_t *ddt;
775
776 ddt = kmem_zalloc(sizeof (*ddt), KM_SLEEP);
777
778 mutex_init(&ddt->ddt_lock, NULL, MUTEX_DEFAULT, NULL);
779 avl_create(&ddt->ddt_tree, ddt_entry_compare,
780 sizeof (ddt_entry_t), offsetof(ddt_entry_t, dde_node));
781 avl_create(&ddt->ddt_repair_tree, ddt_entry_compare,
782 sizeof (ddt_entry_t), offsetof(ddt_entry_t, dde_node));
783 ddt->ddt_checksum = c;
784 ddt->ddt_spa = spa;
785 ddt->ddt_os = spa->spa_meta_objset;
786
787 return (ddt);
788 }
789
790 static void
791 ddt_table_free(ddt_t *ddt)
792 {
793 ASSERT(avl_numnodes(&ddt->ddt_tree) == 0);
794 ASSERT(avl_numnodes(&ddt->ddt_repair_tree) == 0);
795 avl_destroy(&ddt->ddt_tree);
796 avl_destroy(&ddt->ddt_repair_tree);
797 mutex_destroy(&ddt->ddt_lock);
798 kmem_free(ddt, sizeof (*ddt));
799 }
800
801 void
802 ddt_create(spa_t *spa)
803 {
804 spa->spa_dedup_checksum = ZIO_DEDUPCHECKSUM;
805
806 for (enum zio_checksum c = 0; c < ZIO_CHECKSUM_FUNCTIONS; c++)
807 spa->spa_ddt[c] = ddt_table_alloc(spa, c);
808 }
809
810 int
811 ddt_load(spa_t *spa)
812 {
813 int error;
814
815 ddt_create(spa);
816
817 error = zap_lookup(spa->spa_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
818 DMU_POOL_DDT_STATS, sizeof (uint64_t), 1,
819 &spa->spa_ddt_stat_object);
820
821 if (error)
822 return (error == ENOENT ? 0 : error);
823
824 for (enum zio_checksum c = 0; c < ZIO_CHECKSUM_FUNCTIONS; c++) {
825 ddt_t *ddt = spa->spa_ddt[c];
826 for (enum ddt_type type = 0; type < DDT_TYPES; type++) {
827 for (enum ddt_class class = 0; class < DDT_CLASSES;
828 class++) {
829 error = ddt_object_load(ddt, type, class);
830 if (error != 0 && error != ENOENT)
831 return (error);
832 }
833 }
834
835 /*
836 * Seed the cached histograms.
837 */
838 bcopy(ddt->ddt_histogram, &ddt->ddt_histogram_cache,
839 sizeof (ddt->ddt_histogram));
840 }
841
842 return (0);
843 }
844
845 void
846 ddt_unload(spa_t *spa)
847 {
848 for (enum zio_checksum c = 0; c < ZIO_CHECKSUM_FUNCTIONS; c++) {
849 if (spa->spa_ddt[c]) {
850 ddt_table_free(spa->spa_ddt[c]);
851 spa->spa_ddt[c] = NULL;
852 }
853 }
854 }
855
856 boolean_t
857 ddt_class_contains(spa_t *spa, enum ddt_class max_class, const blkptr_t *bp)
858 {
859 ddt_t *ddt;
860 ddt_entry_t dde;
861
862 if (!BP_GET_DEDUP(bp))
863 return (B_FALSE);
864
865 if (max_class == DDT_CLASS_UNIQUE)
866 return (B_TRUE);
867
868 ddt = spa->spa_ddt[BP_GET_CHECKSUM(bp)];
869
870 ddt_key_fill(&dde.dde_key, bp);
871
872 for (enum ddt_type type = 0; type < DDT_TYPES; type++)
873 for (enum ddt_class class = 0; class <= max_class; class++)
874 if (ddt_object_lookup(ddt, type, class, &dde) == 0)
875 return (B_TRUE);
876
877 return (B_FALSE);
878 }
879
880 ddt_entry_t *
881 ddt_repair_start(ddt_t *ddt, const blkptr_t *bp)
882 {
883 ddt_key_t ddk;
884 ddt_entry_t *dde;
885
886 ddt_key_fill(&ddk, bp);
887
888 dde = ddt_alloc(&ddk);
889
890 for (enum ddt_type type = 0; type < DDT_TYPES; type++) {
891 for (enum ddt_class class = 0; class < DDT_CLASSES; class++) {
892 /*
893 * We can only do repair if there are multiple copies
894 * of the block. For anything in the UNIQUE class,
895 * there's definitely only one copy, so don't even try.
896 */
897 if (class != DDT_CLASS_UNIQUE &&
898 ddt_object_lookup(ddt, type, class, dde) == 0)
899 return (dde);
900 }
901 }
902
903 bzero(dde->dde_phys, sizeof (dde->dde_phys));
904
905 return (dde);
906 }
907
908 void
909 ddt_repair_done(ddt_t *ddt, ddt_entry_t *dde)
910 {
911 avl_index_t where;
912
913 ddt_enter(ddt);
914
915 if (dde->dde_repair_data != NULL && spa_writeable(ddt->ddt_spa) &&
916 avl_find(&ddt->ddt_repair_tree, dde, &where) == NULL)
917 avl_insert(&ddt->ddt_repair_tree, dde, where);
918 else
919 ddt_free(dde);
920
921 ddt_exit(ddt);
922 }
923
924 static void
925 ddt_repair_entry_done(zio_t *zio)
926 {
927 ddt_entry_t *rdde = zio->io_private;
928
929 ddt_free(rdde);
930 }
931
932 static void
933 ddt_repair_entry(ddt_t *ddt, ddt_entry_t *dde, ddt_entry_t *rdde, zio_t *rio)
934 {
935 ddt_phys_t *ddp = dde->dde_phys;
936 ddt_phys_t *rddp = rdde->dde_phys;
937 ddt_key_t *ddk = &dde->dde_key;
938 ddt_key_t *rddk = &rdde->dde_key;
939 zio_t *zio;
940 blkptr_t blk;
941
942 zio = zio_null(rio, rio->io_spa, NULL,
943 ddt_repair_entry_done, rdde, rio->io_flags);
944
945 for (int p = 0; p < DDT_PHYS_TYPES; p++, ddp++, rddp++) {
946 if (ddp->ddp_phys_birth == 0 ||
947 ddp->ddp_phys_birth != rddp->ddp_phys_birth ||
948 bcmp(ddp->ddp_dva, rddp->ddp_dva, sizeof (ddp->ddp_dva)))
949 continue;
950 ddt_bp_create(ddt->ddt_checksum, ddk, ddp, &blk);
951 zio_nowait(zio_rewrite(zio, zio->io_spa, 0, &blk,
952 rdde->dde_repair_data, DDK_GET_PSIZE(rddk), NULL, NULL,
953 ZIO_PRIORITY_SYNC_WRITE, ZIO_DDT_CHILD_FLAGS(zio), NULL));
954 }
955
956 zio_nowait(zio);
957 }
958
959 static void
960 ddt_repair_table(ddt_t *ddt, zio_t *rio)
961 {
962 spa_t *spa = ddt->ddt_spa;
963 ddt_entry_t *dde, *rdde_next, *rdde;
964 avl_tree_t *t = &ddt->ddt_repair_tree;
965 blkptr_t blk;
966
967 if (spa_sync_pass(spa) > 1)
968 return;
969
970 ddt_enter(ddt);
971 for (rdde = avl_first(t); rdde != NULL; rdde = rdde_next) {
972 rdde_next = AVL_NEXT(t, rdde);
973 avl_remove(&ddt->ddt_repair_tree, rdde);
974 ddt_exit(ddt);
975 ddt_bp_create(ddt->ddt_checksum, &rdde->dde_key, NULL, &blk);
976 dde = ddt_repair_start(ddt, &blk);
977 ddt_repair_entry(ddt, dde, rdde, rio);
978 ddt_repair_done(ddt, dde);
979 ddt_enter(ddt);
980 }
981 ddt_exit(ddt);
982 }
983
984 static void
985 ddt_sync_entry(ddt_t *ddt, ddt_entry_t *dde, dmu_tx_t *tx, uint64_t txg)
986 {
987 dsl_pool_t *dp = ddt->ddt_spa->spa_dsl_pool;
988 ddt_phys_t *ddp = dde->dde_phys;
989 ddt_key_t *ddk = &dde->dde_key;
990 enum ddt_type otype = dde->dde_type;
991 enum ddt_type ntype = DDT_TYPE_CURRENT;
992 enum ddt_class oclass = dde->dde_class;
993 enum ddt_class nclass;
994 uint64_t total_refcnt = 0;
995
996 ASSERT(dde->dde_loaded);
997 ASSERT(!dde->dde_loading);
998
999 for (int p = 0; p < DDT_PHYS_TYPES; p++, ddp++) {
1000 ASSERT(dde->dde_lead_zio[p] == NULL);
1001 ASSERT((int64_t)ddp->ddp_refcnt >= 0);
1002 if (ddp->ddp_phys_birth == 0) {
1003 ASSERT(ddp->ddp_refcnt == 0);
1004 continue;
1005 }
1006 if (p == DDT_PHYS_DITTO) {
1007 if (ddt_ditto_copies_needed(ddt, dde, NULL) == 0)
1008 ddt_phys_free(ddt, ddk, ddp, txg);
1009 continue;
1010 }
1011 if (ddp->ddp_refcnt == 0)
1012 ddt_phys_free(ddt, ddk, ddp, txg);
1013 total_refcnt += ddp->ddp_refcnt;
1014 }
1015
1016 if (dde->dde_phys[DDT_PHYS_DITTO].ddp_phys_birth != 0)
1017 nclass = DDT_CLASS_DITTO;
1018 else if (total_refcnt > 1)
1019 nclass = DDT_CLASS_DUPLICATE;
1020 else
1021 nclass = DDT_CLASS_UNIQUE;
1022
1023 if (otype != DDT_TYPES &&
1024 (otype != ntype || oclass != nclass || total_refcnt == 0)) {
1025 VERIFY(ddt_object_remove(ddt, otype, oclass, dde, tx) == 0);
1026 ASSERT(ddt_object_lookup(ddt, otype, oclass, dde) == ENOENT);
1027 }
1028
1029 if (total_refcnt != 0) {
1030 dde->dde_type = ntype;
1031 dde->dde_class = nclass;
1032 ddt_stat_update(ddt, dde, 0);
1033 if (!ddt_object_exists(ddt, ntype, nclass))
1034 ddt_object_create(ddt, ntype, nclass, tx);
1035 VERIFY(ddt_object_update(ddt, ntype, nclass, dde, tx) == 0);
1036
1037 /*
1038 * If the class changes, the order that we scan this bp
1039 * changes. If it decreases, we could miss it, so
1040 * scan it right now. (This covers both class changing
1041 * while we are doing ddt_walk(), and when we are
1042 * traversing.)
1043 */
1044 if (nclass < oclass) {
1045 dsl_scan_ddt_entry(dp->dp_scan,
1046 ddt->ddt_checksum, dde, tx);
1047 }
1048 }
1049 }
1050
1051 static void
1052 ddt_sync_table(ddt_t *ddt, dmu_tx_t *tx, uint64_t txg)
1053 {
1054 spa_t *spa = ddt->ddt_spa;
1055 ddt_entry_t *dde;
1056 void *cookie = NULL;
1057
1058 if (avl_numnodes(&ddt->ddt_tree) == 0)
1059 return;
1060
1061 ASSERT(spa->spa_uberblock.ub_version >= SPA_VERSION_DEDUP);
1062
1063 if (spa->spa_ddt_stat_object == 0) {
1064 spa->spa_ddt_stat_object = zap_create(ddt->ddt_os,
1065 DMU_OT_DDT_STATS, DMU_OT_NONE, 0, tx);
1066 VERIFY(zap_add(ddt->ddt_os, DMU_POOL_DIRECTORY_OBJECT,
1067 DMU_POOL_DDT_STATS, sizeof (uint64_t), 1,
1068 &spa->spa_ddt_stat_object, tx) == 0);
1069 }
1070
1071 while ((dde = avl_destroy_nodes(&ddt->ddt_tree, &cookie)) != NULL) {
1072 ddt_sync_entry(ddt, dde, tx, txg);
1073 ddt_free(dde);
1074 }
1075
1076 for (enum ddt_type type = 0; type < DDT_TYPES; type++) {
1077 uint64_t count = 0;
1078 for (enum ddt_class class = 0; class < DDT_CLASSES; class++) {
1079 if (ddt_object_exists(ddt, type, class)) {
1080 ddt_object_sync(ddt, type, class, tx);
1081 count += ddt_object_count(ddt, type, class);
1082 }
1083 }
1084 for (enum ddt_class class = 0; class < DDT_CLASSES; class++) {
1085 if (count == 0 && ddt_object_exists(ddt, type, class))
1086 ddt_object_destroy(ddt, type, class, tx);
1087 }
1088 }
1089
1090 bcopy(ddt->ddt_histogram, &ddt->ddt_histogram_cache,
1091 sizeof (ddt->ddt_histogram));
1092 }
1093
1094 void
1095 ddt_sync(spa_t *spa, uint64_t txg)
1096 {
1097 dmu_tx_t *tx;
1098 zio_t *rio = zio_root(spa, NULL, NULL,
1099 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE);
1100
1101 ASSERT(spa_syncing_txg(spa) == txg);
1102
1103 tx = dmu_tx_create_assigned(spa->spa_dsl_pool, txg);
1104
1105 for (enum zio_checksum c = 0; c < ZIO_CHECKSUM_FUNCTIONS; c++) {
1106 ddt_t *ddt = spa->spa_ddt[c];
1107 if (ddt == NULL)
1108 continue;
1109 ddt_sync_table(ddt, tx, txg);
1110 ddt_repair_table(ddt, rio);
1111 }
1112
1113 (void) zio_wait(rio);
1114
1115 dmu_tx_commit(tx);
1116 }
1117
1118 int
1119 ddt_walk(spa_t *spa, ddt_bookmark_t *ddb, ddt_entry_t *dde)
1120 {
1121 do {
1122 do {
1123 do {
1124 ddt_t *ddt = spa->spa_ddt[ddb->ddb_checksum];
1125 int error = ENOENT;
1126 if (ddt_object_exists(ddt, ddb->ddb_type,
1127 ddb->ddb_class)) {
1128 error = ddt_object_walk(ddt,
1129 ddb->ddb_type, ddb->ddb_class,
1130 &ddb->ddb_cursor, dde);
1131 }
1132 dde->dde_type = ddb->ddb_type;
1133 dde->dde_class = ddb->ddb_class;
1134 if (error == 0)
1135 return (0);
1136 if (error != ENOENT)
1137 return (error);
1138 ddb->ddb_cursor = 0;
1139 } while (++ddb->ddb_checksum < ZIO_CHECKSUM_FUNCTIONS);
1140 ddb->ddb_checksum = 0;
1141 } while (++ddb->ddb_type < DDT_TYPES);
1142 ddb->ddb_type = 0;
1143 } while (++ddb->ddb_class < DDT_CLASSES);
1144
1145 return (ENOENT);
1146 }