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 * Copyright (c) 2013 by Delphix. All rights reserved.
25 */
26
27 #include <sys/zfs_context.h>
28 #include <sys/spa.h>
29 #include <sys/spa_impl.h>
30 #include <sys/zio.h>
31 #include <sys/ddt.h>
32 #include <sys/zap.h>
33 #include <sys/dmu_tx.h>
34 #include <sys/arc.h>
35 #include <sys/dsl_pool.h>
36 #include <sys/zio_checksum.h>
37 #include <sys/zio_compress.h>
38 #include <sys/dsl_scan.h>
39
40 /*
41 * Enable/disable prefetching of dedup-ed blocks which are going to be freed.
42 */
43 int zfs_dedup_prefetch = 1;
44
45 static const ddt_ops_t *ddt_ops[DDT_TYPES] = {
46 &ddt_zap_ops,
47 };
48
49 static const char *ddt_class_name[DDT_CLASSES] = {
50 "ditto",
51 "duplicate",
52 "unique",
53 };
54
55 static void
56 ddt_object_create(ddt_t *ddt, enum ddt_type type, enum ddt_class class,
57 dmu_tx_t *tx)
58 {
59 spa_t *spa = ddt->ddt_spa;
60 objset_t *os = ddt->ddt_os;
61 uint64_t *objectp = &ddt->ddt_object[type][class];
62 boolean_t prehash = zio_checksum_table[ddt->ddt_checksum].ci_dedup;
63 char name[DDT_NAMELEN];
64
65 ddt_object_name(ddt, type, class, name);
66
67 ASSERT(*objectp == 0);
68 VERIFY(ddt_ops[type]->ddt_op_create(os, objectp, tx, prehash) == 0);
69 ASSERT(*objectp != 0);
70
71 VERIFY(zap_add(os, DMU_POOL_DIRECTORY_OBJECT, name,
72 sizeof (uint64_t), 1, objectp, tx) == 0);
73
74 VERIFY(zap_add(os, spa->spa_ddt_stat_object, name,
75 sizeof (uint64_t), sizeof (ddt_histogram_t) / sizeof (uint64_t),
76 &ddt->ddt_histogram[type][class], tx) == 0);
77 }
78
79 static void
80 ddt_object_destroy(ddt_t *ddt, enum ddt_type type, enum ddt_class class,
81 dmu_tx_t *tx)
82 {
83 spa_t *spa = ddt->ddt_spa;
84 objset_t *os = ddt->ddt_os;
85 uint64_t *objectp = &ddt->ddt_object[type][class];
86 char name[DDT_NAMELEN];
87
88 ddt_object_name(ddt, type, class, name);
89
90 ASSERT(*objectp != 0);
91 ASSERT(ddt_object_count(ddt, type, class) == 0);
92 ASSERT(ddt_histogram_empty(&ddt->ddt_histogram[type][class]));
93 VERIFY(zap_remove(os, DMU_POOL_DIRECTORY_OBJECT, name, tx) == 0);
94 VERIFY(zap_remove(os, spa->spa_ddt_stat_object, name, tx) == 0);
95 VERIFY(ddt_ops[type]->ddt_op_destroy(os, *objectp, tx) == 0);
96 bzero(&ddt->ddt_object_stats[type][class], sizeof (ddt_object_t));
97
98 *objectp = 0;
99 }
100
101 static int
102 ddt_object_load(ddt_t *ddt, enum ddt_type type, enum ddt_class class)
103 {
104 ddt_object_t *ddo = &ddt->ddt_object_stats[type][class];
105 dmu_object_info_t doi;
106 char name[DDT_NAMELEN];
107 int error;
108
109 ddt_object_name(ddt, type, class, name);
110
111 error = zap_lookup(ddt->ddt_os, DMU_POOL_DIRECTORY_OBJECT, name,
112 sizeof (uint64_t), 1, &ddt->ddt_object[type][class]);
113
114 if (error)
115 return (error);
116
117 error = zap_lookup(ddt->ddt_os, ddt->ddt_spa->spa_ddt_stat_object, name,
118 sizeof (uint64_t), sizeof (ddt_histogram_t) / sizeof (uint64_t),
119 &ddt->ddt_histogram[type][class]);
120
121 /*
122 * Seed the cached statistics.
123 */
124 VERIFY(ddt_object_info(ddt, type, class, &doi) == 0);
125
126 ddo->ddo_count = ddt_object_count(ddt, type, class);
127 ddo->ddo_dspace = doi.doi_physical_blocks_512 << 9;
128 ddo->ddo_mspace = doi.doi_fill_count * doi.doi_data_block_size;
129
130 ASSERT(error == 0);
131 return (error);
132 }
133
134 static void
135 ddt_object_sync(ddt_t *ddt, enum ddt_type type, enum ddt_class class,
136 dmu_tx_t *tx)
137 {
138 ddt_object_t *ddo = &ddt->ddt_object_stats[type][class];
139 dmu_object_info_t doi;
140 char name[DDT_NAMELEN];
141
142 ddt_object_name(ddt, type, class, name);
143
144 VERIFY(zap_update(ddt->ddt_os, ddt->ddt_spa->spa_ddt_stat_object, name,
145 sizeof (uint64_t), sizeof (ddt_histogram_t) / sizeof (uint64_t),
146 &ddt->ddt_histogram[type][class], tx) == 0);
147
148 /*
149 * Cache DDT statistics; this is the only time they'll change.
150 */
151 VERIFY(ddt_object_info(ddt, type, class, &doi) == 0);
152
153 ddo->ddo_count = ddt_object_count(ddt, type, class);
154 ddo->ddo_dspace = doi.doi_physical_blocks_512 << 9;
155 ddo->ddo_mspace = doi.doi_fill_count * doi.doi_data_block_size;
156 }
157
158 static int
159 ddt_object_lookup(ddt_t *ddt, enum ddt_type type, enum ddt_class class,
160 ddt_entry_t *dde)
161 {
162 if (!ddt_object_exists(ddt, type, class))
163 return (SET_ERROR(ENOENT));
164
165 return (ddt_ops[type]->ddt_op_lookup(ddt->ddt_os,
166 ddt->ddt_object[type][class], dde));
167 }
168
169 static void
170 ddt_object_prefetch(ddt_t *ddt, enum ddt_type type, enum ddt_class class,
171 ddt_entry_t *dde)
172 {
173 if (!ddt_object_exists(ddt, type, class))
174 return;
175
176 ddt_ops[type]->ddt_op_prefetch(ddt->ddt_os,
177 ddt->ddt_object[type][class], dde);
178 }
179
180 int
181 ddt_object_update(ddt_t *ddt, enum ddt_type type, enum ddt_class ddt_class,
182 ddt_entry_t *dde, dmu_tx_t *tx)
183 {
184 ASSERT(ddt_object_exists(ddt, type, ddt_class));
185
186 return (ddt_ops[type]->ddt_op_update(ddt->ddt_os,
187 ddt->ddt_object[type][ddt_class], dde, tx));
188 }
189
190 static int
191 ddt_object_remove(ddt_t *ddt, enum ddt_type type, enum ddt_class class,
192 ddt_entry_t *dde, dmu_tx_t *tx)
193 {
194 ASSERT(ddt_object_exists(ddt, type, class));
195
196 return (ddt_ops[type]->ddt_op_remove(ddt->ddt_os,
197 ddt->ddt_object[type][class], dde, tx));
198 }
199
200 int
201 ddt_object_walk(ddt_t *ddt, enum ddt_type type, enum ddt_class ddt_class,
202 uint64_t *walk, ddt_entry_t *dde)
203 {
204 ASSERT(ddt_object_exists(ddt, type, ddt_class));
205
206 return (ddt_ops[type]->ddt_op_walk(ddt->ddt_os,
207 ddt->ddt_object[type][ddt_class], dde, walk));
208 }
209
210 uint64_t
211 ddt_object_count(ddt_t *ddt, enum ddt_type type, enum ddt_class ddt_class)
212 {
213 ASSERT(ddt_object_exists(ddt, type, ddt_class));
214
215 return (ddt_ops[type]->ddt_op_count(ddt->ddt_os,
216 ddt->ddt_object[type][ddt_class]));
217 }
218
219 int
220 ddt_object_info(ddt_t *ddt, enum ddt_type type, enum ddt_class ddt_class,
221 dmu_object_info_t *doi)
222 {
223 if (!ddt_object_exists(ddt, type, ddt_class))
224 return (SET_ERROR(ENOENT));
225
226 return (dmu_object_info(ddt->ddt_os, ddt->ddt_object[type][ddt_class],
227 doi));
228 }
229
230 boolean_t
231 ddt_object_exists(ddt_t *ddt, enum ddt_type type, enum ddt_class ddt_class)
232 {
233 return (!!ddt->ddt_object[type][ddt_class]);
234 }
235
236 void
237 ddt_object_name(ddt_t *ddt, enum ddt_type type, enum ddt_class ddt_class,
238 char *name)
239 {
240 (void) sprintf(name, DMU_POOL_DDT,
241 zio_checksum_table[ddt->ddt_checksum].ci_name,
242 ddt_ops[type]->ddt_op_name, ddt_class_name[ddt_class]);
243 }
244
245 void
246 ddt_bp_fill(const ddt_phys_t *ddp, blkptr_t *bp, uint64_t txg)
247 {
248 ASSERT(txg != 0);
249
250 for (int d = 0; d < SPA_DVAS_PER_BP; d++)
251 bp->blk_dva[d] = ddp->ddp_dva[d];
252 BP_SET_BIRTH(bp, txg, ddp->ddp_phys_birth);
253 }
254
255 void
256 ddt_bp_create(enum zio_checksum checksum,
257 const ddt_key_t *ddk, const ddt_phys_t *ddp, blkptr_t *bp)
258 {
259 BP_ZERO(bp);
260
261 if (ddp != NULL)
262 ddt_bp_fill(ddp, bp, ddp->ddp_phys_birth);
263
264 bp->blk_cksum = ddk->ddk_cksum;
265 bp->blk_fill = 1;
266
267 BP_SET_LSIZE(bp, DDK_GET_LSIZE(ddk));
268 BP_SET_PSIZE(bp, DDK_GET_PSIZE(ddk));
269 BP_SET_COMPRESS(bp, DDK_GET_COMPRESS(ddk));
270 BP_SET_CHECKSUM(bp, checksum);
271 BP_SET_TYPE(bp, DMU_OT_DEDUP);
272 BP_SET_LEVEL(bp, 0);
273 BP_SET_DEDUP(bp, 0);
274 BP_SET_BYTEORDER(bp, ZFS_HOST_BYTEORDER);
275 }
276
277 void
278 ddt_key_fill(ddt_key_t *ddk, const blkptr_t *bp)
279 {
280 ddk->ddk_cksum = bp->blk_cksum;
281 ddk->ddk_prop = 0;
282
283 DDK_SET_LSIZE(ddk, BP_GET_LSIZE(bp));
284 DDK_SET_PSIZE(ddk, BP_GET_PSIZE(bp));
285 DDK_SET_COMPRESS(ddk, BP_GET_COMPRESS(bp));
286 }
287
288 void
289 ddt_phys_fill(ddt_phys_t *ddp, const blkptr_t *bp)
290 {
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 bzero(ddp, sizeof (*ddp));
302 }
303
304 void
305 ddt_phys_addref(ddt_phys_t *ddp)
306 {
307 ddp->ddp_refcnt++;
308 }
309
310 void
311 ddt_phys_decref(ddt_phys_t *ddp)
312 {
313 ASSERT((int64_t)ddp->ddp_refcnt > 0);
314 ddp->ddp_refcnt--;
315 }
316
317 void
318 ddt_phys_free(ddt_t *ddt, ddt_key_t *ddk, ddt_phys_t *ddp, uint64_t txg)
319 {
320 blkptr_t blk;
321
322 ddt_bp_create(ddt->ddt_checksum, ddk, ddp, &blk);
323 ddt_phys_clear(ddp);
324 zio_free(ddt->ddt_spa, txg, &blk);
325 }
326
327 ddt_phys_t *
328 ddt_phys_select(const ddt_entry_t *dde, const blkptr_t *bp)
329 {
330 ddt_phys_t *ddp = (ddt_phys_t *)dde->dde_phys;
331
332 for (int p = 0; p < DDT_PHYS_TYPES; p++, ddp++) {
333 if (DVA_EQUAL(BP_IDENTITY(bp), &ddp->ddp_dva[0]) &&
334 BP_PHYSICAL_BIRTH(bp) == ddp->ddp_phys_birth)
335 return (ddp);
336 }
337 return (NULL);
338 }
339
340 uint64_t
341 ddt_phys_total_refcnt(const ddt_entry_t *dde)
342 {
343 uint64_t refcnt = 0;
344
345 for (int p = DDT_PHYS_SINGLE; p <= DDT_PHYS_TRIPLE; p++)
346 refcnt += dde->dde_phys[p].ddp_refcnt;
347
348 return (refcnt);
349 }
350
351 static void
352 ddt_stat_generate(ddt_t *ddt, ddt_entry_t *dde, ddt_stat_t *dds)
353 {
354 spa_t *spa = ddt->ddt_spa;
355 ddt_phys_t *ddp = dde->dde_phys;
356 ddt_key_t *ddk = &dde->dde_key;
357 uint64_t lsize = DDK_GET_LSIZE(ddk);
358 uint64_t psize = DDK_GET_PSIZE(ddk);
359
360 bzero(dds, sizeof (*dds));
361
362 for (int p = 0; p < DDT_PHYS_TYPES; p++, ddp++) {
363 uint64_t dsize = 0;
364 uint64_t refcnt = ddp->ddp_refcnt;
365
366 if (ddp->ddp_phys_birth == 0)
367 continue;
368
369 for (int d = 0; d < SPA_DVAS_PER_BP; d++)
370 dsize += dva_get_dsize_sync(spa, &ddp->ddp_dva[d]);
371
372 dds->dds_blocks += 1;
373 dds->dds_lsize += lsize;
374 dds->dds_psize += psize;
375 dds->dds_dsize += dsize;
376
377 dds->dds_ref_blocks += refcnt;
378 dds->dds_ref_lsize += lsize * refcnt;
379 dds->dds_ref_psize += psize * refcnt;
380 dds->dds_ref_dsize += dsize * refcnt;
381 }
382 }
383
384 void
385 ddt_stat_add(ddt_stat_t *dst, const ddt_stat_t *src, uint64_t neg)
386 {
387 const uint64_t *s = (const uint64_t *)src;
388 uint64_t *d = (uint64_t *)dst;
389 uint64_t *d_end = (uint64_t *)(dst + 1);
390
391 ASSERT(neg == 0 || neg == -1ULL); /* add or subtract */
392
393 while (d < d_end)
394 *d++ += (*s++ ^ neg) - neg;
395 }
396
397 static void
398 ddt_stat_update(ddt_t *ddt, ddt_entry_t *dde, uint64_t neg)
399 {
400 ddt_stat_t dds;
401 ddt_histogram_t *ddh;
402 int bucket;
403
404 ddt_stat_generate(ddt, dde, &dds);
405
406 bucket = highbit(dds.dds_ref_blocks) - 1;
407 ASSERT(bucket >= 0);
408
409 ddh = &ddt->ddt_histogram[dde->dde_type][dde->dde_class];
410
411 ddt_stat_add(&ddh->ddh_stat[bucket], &dds, neg);
412 }
413
414 void
415 ddt_histogram_add(ddt_histogram_t *dst, const ddt_histogram_t *src)
416 {
417 for (int h = 0; h < 64; h++)
418 ddt_stat_add(&dst->ddh_stat[h], &src->ddh_stat[h], 0);
419 }
420
421 void
422 ddt_histogram_stat(ddt_stat_t *dds, const ddt_histogram_t *ddh)
423 {
424 bzero(dds, sizeof (*dds));
425
426 for (int h = 0; h < 64; h++)
427 ddt_stat_add(dds, &ddh->ddh_stat[h], 0);
428 }
429
430 boolean_t
431 ddt_histogram_empty(const ddt_histogram_t *ddh)
432 {
433 const uint64_t *s = (const uint64_t *)ddh;
434 const uint64_t *s_end = (const uint64_t *)(ddh + 1);
435
436 while (s < s_end)
437 if (*s++ != 0)
438 return (B_FALSE);
439
440 return (B_TRUE);
441 }
442
443 void
444 ddt_get_dedup_object_stats(spa_t *spa, ddt_object_t *ddo_total)
445 {
446 /* Sum the statistics we cached in ddt_object_sync(). */
447 for (enum zio_checksum c = 0; c < ZIO_CHECKSUM_FUNCTIONS; c++) {
448 ddt_t *ddt = spa->spa_ddt[c];
449 for (enum ddt_type type = 0; type < DDT_TYPES; type++) {
450 for (enum ddt_class class = 0; class < DDT_CLASSES;
451 class++) {
452 ddt_object_t *ddo =
453 &ddt->ddt_object_stats[type][class];
454 ddo_total->ddo_count += ddo->ddo_count;
455 ddo_total->ddo_dspace += ddo->ddo_dspace;
456 ddo_total->ddo_mspace += ddo->ddo_mspace;
457 }
458 }
459 }
460
461 /* ... and compute the averages. */
462 if (ddo_total->ddo_count != 0) {
463 ddo_total->ddo_dspace /= ddo_total->ddo_count;
464 ddo_total->ddo_mspace /= ddo_total->ddo_count;
465 }
466 }
467
468 void
469 ddt_get_dedup_histogram(spa_t *spa, ddt_histogram_t *ddh)
470 {
471 for (enum zio_checksum c = 0; c < ZIO_CHECKSUM_FUNCTIONS; c++) {
472 ddt_t *ddt = spa->spa_ddt[c];
473 for (enum ddt_type type = 0; type < DDT_TYPES; type++) {
474 for (enum ddt_class class = 0; class < DDT_CLASSES;
475 class++) {
476 ddt_histogram_add(ddh,
477 &ddt->ddt_histogram_cache[type][class]);
478 }
479 }
480 }
481 }
482
483 void
484 ddt_get_dedup_stats(spa_t *spa, ddt_stat_t *dds_total)
485 {
486 ddt_histogram_t *ddh_total;
487
488 ddh_total = kmem_zalloc(sizeof (ddt_histogram_t), KM_SLEEP);
489 ddt_get_dedup_histogram(spa, ddh_total);
490 ddt_histogram_stat(dds_total, ddh_total);
491 kmem_free(ddh_total, sizeof (ddt_histogram_t));
492 }
493
494 uint64_t
495 ddt_get_dedup_dspace(spa_t *spa)
496 {
497 ddt_stat_t dds_total = { 0 };
498
499 ddt_get_dedup_stats(spa, &dds_total);
500 return (dds_total.dds_ref_dsize - dds_total.dds_dsize);
501 }
502
503 uint64_t
504 ddt_get_pool_dedup_ratio(spa_t *spa)
505 {
506 ddt_stat_t dds_total = { 0 };
507
508 ddt_get_dedup_stats(spa, &dds_total);
509 if (dds_total.dds_dsize == 0)
510 return (100);
511
512 return (dds_total.dds_ref_dsize * 100 / dds_total.dds_dsize);
513 }
514
515 int
516 ddt_ditto_copies_needed(ddt_t *ddt, ddt_entry_t *dde, ddt_phys_t *ddp_willref)
517 {
518 spa_t *spa = ddt->ddt_spa;
519 uint64_t total_refcnt = 0;
520 uint64_t ditto = spa->spa_dedup_ditto;
521 int total_copies = 0;
522 int desired_copies = 0;
523
524 for (int p = DDT_PHYS_SINGLE; p <= DDT_PHYS_TRIPLE; p++) {
525 ddt_phys_t *ddp = &dde->dde_phys[p];
526 zio_t *zio = dde->dde_lead_zio[p];
527 uint64_t refcnt = ddp->ddp_refcnt; /* committed refs */
528 if (zio != NULL)
529 refcnt += zio->io_parent_count; /* pending refs */
530 if (ddp == ddp_willref)
531 refcnt++; /* caller's ref */
532 if (refcnt != 0) {
533 total_refcnt += refcnt;
534 total_copies += p;
535 }
536 }
537
538 if (ditto == 0 || ditto > UINT32_MAX)
539 ditto = UINT32_MAX;
540
541 if (total_refcnt >= 1)
542 desired_copies++;
543 if (total_refcnt >= ditto)
544 desired_copies++;
545 if (total_refcnt >= ditto * ditto)
546 desired_copies++;
547
548 return (MAX(desired_copies, total_copies) - total_copies);
549 }
550
551 int
552 ddt_ditto_copies_present(ddt_entry_t *dde)
553 {
554 ddt_phys_t *ddp = &dde->dde_phys[DDT_PHYS_DITTO];
555 dva_t *dva = ddp->ddp_dva;
556 int copies = 0 - DVA_GET_GANG(dva);
557
558 for (int d = 0; d < SPA_DVAS_PER_BP; d++, dva++)
559 if (DVA_IS_VALID(dva))
560 copies++;
561
562 ASSERT(copies >= 0 && copies < SPA_DVAS_PER_BP);
563
564 return (copies);
565 }
566
567 size_t
568 ddt_compress(void *src, uchar_t *dst, size_t s_len, size_t d_len)
569 {
570 uchar_t *version = dst++;
571 int cpfunc = ZIO_COMPRESS_ZLE;
572 zio_compress_info_t *ci = &zio_compress_table[cpfunc];
573 size_t c_len;
574
575 ASSERT(d_len >= s_len + 1); /* no compression plus version byte */
576
577 c_len = ci->ci_compress(src, dst, s_len, d_len - 1, ci->ci_level);
578
579 if (c_len == s_len) {
580 cpfunc = ZIO_COMPRESS_OFF;
581 bcopy(src, dst, s_len);
582 }
583
584 *version = (ZFS_HOST_BYTEORDER & DDT_COMPRESS_BYTEORDER_MASK) | cpfunc;
585
586 return (c_len + 1);
587 }
588
589 void
590 ddt_decompress(uchar_t *src, void *dst, size_t s_len, size_t d_len)
591 {
592 uchar_t version = *src++;
593 int cpfunc = version & DDT_COMPRESS_FUNCTION_MASK;
594 zio_compress_info_t *ci = &zio_compress_table[cpfunc];
595
596 if (ci->ci_decompress != NULL)
597 (void) ci->ci_decompress(src, dst, s_len, d_len, ci->ci_level);
598 else
599 bcopy(src, dst, d_len);
600
601 if ((version ^ ZFS_HOST_BYTEORDER) & DDT_COMPRESS_BYTEORDER_MASK)
602 byteswap_uint64_array(dst, d_len);
603 }
604
605 ddt_t *
606 ddt_select_by_checksum(spa_t *spa, enum zio_checksum c)
607 {
608 return (spa->spa_ddt[c]);
609 }
610
611 ddt_t *
612 ddt_select(spa_t *spa, const blkptr_t *bp)
613 {
614 return (spa->spa_ddt[BP_GET_CHECKSUM(bp)]);
615 }
616
617 void
618 ddt_enter(ddt_t *ddt)
619 {
620 mutex_enter(&ddt->ddt_lock);
621 }
622
623 void
624 ddt_exit(ddt_t *ddt)
625 {
626 mutex_exit(&ddt->ddt_lock);
627 }
628
629 static ddt_entry_t *
630 ddt_alloc(const ddt_key_t *ddk)
631 {
632 ddt_entry_t *dde;
633
634 dde = kmem_zalloc(sizeof (ddt_entry_t), KM_SLEEP);
635 cv_init(&dde->dde_cv, NULL, CV_DEFAULT, NULL);
636
637 dde->dde_key = *ddk;
638
639 return (dde);
640 }
641
642 static void
643 ddt_free(ddt_entry_t *dde)
644 {
645 ASSERT(!dde->dde_loading);
646
647 for (int p = 0; p < DDT_PHYS_TYPES; p++)
648 ASSERT(dde->dde_lead_zio[p] == NULL);
649
650 if (dde->dde_repair_data != NULL)
651 zio_buf_free(dde->dde_repair_data,
652 DDK_GET_PSIZE(&dde->dde_key));
653
654 cv_destroy(&dde->dde_cv);
655 kmem_free(dde, sizeof (*dde));
656 }
657
658 void
659 ddt_remove(ddt_t *ddt, ddt_entry_t *dde)
660 {
661 ASSERT(MUTEX_HELD(&ddt->ddt_lock));
662
663 avl_remove(&ddt->ddt_tree, dde);
664 ddt_free(dde);
665 }
666
667 ddt_entry_t *
668 ddt_lookup(ddt_t *ddt, const blkptr_t *bp, boolean_t add)
669 {
670 ddt_entry_t *dde, dde_search;
671 enum ddt_type type;
672 enum ddt_class class;
673 avl_index_t where;
674 int error;
675
676 ASSERT(MUTEX_HELD(&ddt->ddt_lock));
677
678 ddt_key_fill(&dde_search.dde_key, bp);
679
680 dde = avl_find(&ddt->ddt_tree, &dde_search, &where);
681 if (dde == NULL) {
682 if (!add)
683 return (NULL);
684 dde = ddt_alloc(&dde_search.dde_key);
685 avl_insert(&ddt->ddt_tree, dde, where);
686 }
687
688 while (dde->dde_loading)
689 cv_wait(&dde->dde_cv, &ddt->ddt_lock);
690
691 if (dde->dde_loaded)
692 return (dde);
693
694 dde->dde_loading = B_TRUE;
695
696 ddt_exit(ddt);
697
698 error = ENOENT;
699
700 for (type = 0; type < DDT_TYPES; type++) {
701 for (class = 0; class < DDT_CLASSES; class++) {
702 error = ddt_object_lookup(ddt, type, class, dde);
703 if (error != ENOENT)
704 break;
705 }
706 if (error != ENOENT)
707 break;
708 }
709
710 ASSERT(error == 0 || error == ENOENT);
711
712 ddt_enter(ddt);
713
714 ASSERT(dde->dde_loaded == B_FALSE);
715 ASSERT(dde->dde_loading == B_TRUE);
716
717 dde->dde_type = type; /* will be DDT_TYPES if no entry found */
718 dde->dde_class = class; /* will be DDT_CLASSES if no entry found */
719 dde->dde_loaded = B_TRUE;
720 dde->dde_loading = B_FALSE;
721
722 if (error == 0)
723 ddt_stat_update(ddt, dde, -1ULL);
724
725 cv_broadcast(&dde->dde_cv);
726
727 return (dde);
728 }
729
730 void
731 ddt_prefetch(spa_t *spa, const blkptr_t *bp)
732 {
733 ddt_t *ddt;
734 ddt_entry_t dde;
735
736 if (!zfs_dedup_prefetch || bp == NULL || !BP_GET_DEDUP(bp))
737 return;
738
739 /*
740 * We only remove the DDT once all tables are empty and only
741 * prefetch dedup blocks when there are entries in the DDT.
742 * Thus no locking is required as the DDT can't disappear on us.
743 */
744 ddt = ddt_select(spa, bp);
745 ddt_key_fill(&dde.dde_key, bp);
746
747 for (enum ddt_type type = 0; type < DDT_TYPES; type++) {
748 for (enum ddt_class class = 0; class < DDT_CLASSES; class++) {
749 ddt_object_prefetch(ddt, type, class, &dde);
750 }
751 }
752 }
753
754 int
755 ddt_entry_compare(const void *x1, const void *x2)
756 {
757 const ddt_entry_t *dde1 = x1;
758 const ddt_entry_t *dde2 = x2;
759 const uint64_t *u1 = (const uint64_t *)&dde1->dde_key;
760 const uint64_t *u2 = (const uint64_t *)&dde2->dde_key;
761
762 for (int i = 0; i < DDT_KEY_WORDS; i++) {
763 if (u1[i] < u2[i])
764 return (-1);
765 if (u1[i] > u2[i])
766 return (1);
767 }
768
769 return (0);
770 }
771
772 static ddt_t *
773 ddt_table_alloc(spa_t *spa, enum zio_checksum c)
774 {
775 ddt_t *ddt;
776
777 ddt = kmem_zalloc(sizeof (*ddt), KM_SLEEP);
778
779 mutex_init(&ddt->ddt_lock, NULL, MUTEX_DEFAULT, NULL);
780 avl_create(&ddt->ddt_tree, ddt_entry_compare,
781 sizeof (ddt_entry_t), offsetof(ddt_entry_t, dde_node));
782 avl_create(&ddt->ddt_repair_tree, ddt_entry_compare,
783 sizeof (ddt_entry_t), offsetof(ddt_entry_t, dde_node));
784 ddt->ddt_checksum = c;
785 ddt->ddt_spa = spa;
786 ddt->ddt_os = spa->spa_meta_objset;
787
788 return (ddt);
789 }
790
791 static void
792 ddt_table_free(ddt_t *ddt)
793 {
794 ASSERT(avl_numnodes(&ddt->ddt_tree) == 0);
795 ASSERT(avl_numnodes(&ddt->ddt_repair_tree) == 0);
796 avl_destroy(&ddt->ddt_tree);
797 avl_destroy(&ddt->ddt_repair_tree);
798 mutex_destroy(&ddt->ddt_lock);
799 kmem_free(ddt, sizeof (*ddt));
800 }
801
802 void
803 ddt_create(spa_t *spa)
804 {
805 spa->spa_dedup_checksum = ZIO_DEDUPCHECKSUM;
806
807 for (enum zio_checksum c = 0; c < ZIO_CHECKSUM_FUNCTIONS; c++)
808 spa->spa_ddt[c] = ddt_table_alloc(spa, c);
809 }
810
811 int
812 ddt_load(spa_t *spa)
813 {
814 int error;
815
816 ddt_create(spa);
817
818 error = zap_lookup(spa->spa_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
819 DMU_POOL_DDT_STATS, sizeof (uint64_t), 1,
820 &spa->spa_ddt_stat_object);
821
822 if (error)
823 return (error == ENOENT ? 0 : error);
824
825 for (enum zio_checksum c = 0; c < ZIO_CHECKSUM_FUNCTIONS; c++) {
826 ddt_t *ddt = spa->spa_ddt[c];
827 for (enum ddt_type type = 0; type < DDT_TYPES; type++) {
828 for (enum ddt_class class = 0; class < DDT_CLASSES;
829 class++) {
830 error = ddt_object_load(ddt, type, class);
831 if (error != 0 && error != ENOENT)
832 return (error);
833 }
834 }
835
836 /*
837 * Seed the cached histograms.
838 */
839 bcopy(ddt->ddt_histogram, &ddt->ddt_histogram_cache,
840 sizeof (ddt->ddt_histogram));
841 }
842
843 return (0);
844 }
845
846 void
847 ddt_unload(spa_t *spa)
848 {
849 for (enum zio_checksum c = 0; c < ZIO_CHECKSUM_FUNCTIONS; c++) {
850 if (spa->spa_ddt[c]) {
851 ddt_table_free(spa->spa_ddt[c]);
852 spa->spa_ddt[c] = NULL;
853 }
854 }
855 }
856
857 boolean_t
858 ddt_class_contains(spa_t *spa, enum ddt_class max_class, const blkptr_t *bp)
859 {
860 ddt_t *ddt;
861 ddt_entry_t dde;
862
863 if (!BP_GET_DEDUP(bp))
864 return (B_FALSE);
865
866 if (max_class == DDT_CLASS_UNIQUE)
867 return (B_TRUE);
868
869 ddt = spa->spa_ddt[BP_GET_CHECKSUM(bp)];
870
871 ddt_key_fill(&dde.dde_key, bp);
872
873 for (enum ddt_type type = 0; type < DDT_TYPES; type++)
874 for (enum ddt_class class = 0; class <= max_class; class++)
875 if (ddt_object_lookup(ddt, type, class, &dde) == 0)
876 return (B_TRUE);
877
878 return (B_FALSE);
879 }
880
881 ddt_entry_t *
882 ddt_repair_start(ddt_t *ddt, const blkptr_t *bp)
883 {
884 ddt_key_t ddk;
885 ddt_entry_t *dde;
886
887 ddt_key_fill(&ddk, bp);
888
889 dde = ddt_alloc(&ddk);
890
891 for (enum ddt_type type = 0; type < DDT_TYPES; type++) {
892 for (enum ddt_class class = 0; class < DDT_CLASSES; class++) {
893 /*
894 * We can only do repair if there are multiple copies
895 * of the block. For anything in the UNIQUE class,
896 * there's definitely only one copy, so don't even try.
897 */
898 if (class != DDT_CLASS_UNIQUE &&
899 ddt_object_lookup(ddt, type, class, dde) == 0)
900 return (dde);
901 }
902 }
903
904 bzero(dde->dde_phys, sizeof (dde->dde_phys));
905
906 return (dde);
907 }
908
909 void
910 ddt_repair_done(ddt_t *ddt, ddt_entry_t *dde)
911 {
912 avl_index_t where;
913
914 ddt_enter(ddt);
915
916 if (dde->dde_repair_data != NULL && spa_writeable(ddt->ddt_spa) &&
917 avl_find(&ddt->ddt_repair_tree, dde, &where) == NULL)
918 avl_insert(&ddt->ddt_repair_tree, dde, where);
919 else
920 ddt_free(dde);
921
922 ddt_exit(ddt);
923 }
924
925 static void
926 ddt_repair_entry_done(zio_t *zio)
927 {
928 ddt_entry_t *rdde = zio->io_private;
929
930 ddt_free(rdde);
931 }
932
933 static void
934 ddt_repair_entry(ddt_t *ddt, ddt_entry_t *dde, ddt_entry_t *rdde, zio_t *rio)
935 {
936 ddt_phys_t *ddp = dde->dde_phys;
937 ddt_phys_t *rddp = rdde->dde_phys;
938 ddt_key_t *ddk = &dde->dde_key;
939 ddt_key_t *rddk = &rdde->dde_key;
940 zio_t *zio;
941 blkptr_t blk;
942
943 zio = zio_null(rio, rio->io_spa, NULL,
944 ddt_repair_entry_done, rdde, rio->io_flags);
945
946 for (int p = 0; p < DDT_PHYS_TYPES; p++, ddp++, rddp++) {
947 if (ddp->ddp_phys_birth == 0 ||
948 ddp->ddp_phys_birth != rddp->ddp_phys_birth ||
949 bcmp(ddp->ddp_dva, rddp->ddp_dva, sizeof (ddp->ddp_dva)))
950 continue;
951 ddt_bp_create(ddt->ddt_checksum, ddk, ddp, &blk);
952 zio_nowait(zio_rewrite(zio, zio->io_spa, 0, &blk,
953 rdde->dde_repair_data, DDK_GET_PSIZE(rddk), NULL, NULL,
954 ZIO_PRIORITY_SYNC_WRITE, ZIO_DDT_CHILD_FLAGS(zio), NULL));
955 }
956
957 zio_nowait(zio);
958 }
959
960 static void
961 ddt_repair_table(ddt_t *ddt, zio_t *rio)
962 {
963 spa_t *spa = ddt->ddt_spa;
964 ddt_entry_t *dde, *rdde_next, *rdde;
965 avl_tree_t *t = &ddt->ddt_repair_tree;
966 blkptr_t blk;
967
968 if (spa_sync_pass(spa) > 1)
969 return;
970
971 ddt_enter(ddt);
972 for (rdde = avl_first(t); rdde != NULL; rdde = rdde_next) {
973 rdde_next = AVL_NEXT(t, rdde);
974 avl_remove(&ddt->ddt_repair_tree, rdde);
975 ddt_exit(ddt);
976 ddt_bp_create(ddt->ddt_checksum, &rdde->dde_key, NULL, &blk);
977 dde = ddt_repair_start(ddt, &blk);
978 ddt_repair_entry(ddt, dde, rdde, rio);
979 ddt_repair_done(ddt, dde);
980 ddt_enter(ddt);
981 }
982 ddt_exit(ddt);
983 }
984
985 static void
986 ddt_sync_entry(ddt_t *ddt, ddt_entry_t *dde, dmu_tx_t *tx, uint64_t txg)
987 {
988 dsl_pool_t *dp = ddt->ddt_spa->spa_dsl_pool;
989 ddt_phys_t *ddp = dde->dde_phys;
990 ddt_key_t *ddk = &dde->dde_key;
991 enum ddt_type otype = dde->dde_type;
992 enum ddt_type ntype = DDT_TYPE_CURRENT;
993 enum ddt_class oclass = dde->dde_class;
994 enum ddt_class nclass;
995 uint64_t total_refcnt = 0;
996
997 ASSERT(dde->dde_loaded);
998 ASSERT(!dde->dde_loading);
999
1000 for (int p = 0; p < DDT_PHYS_TYPES; p++, ddp++) {
1001 ASSERT(dde->dde_lead_zio[p] == NULL);
1002 ASSERT((int64_t)ddp->ddp_refcnt >= 0);
1003 if (ddp->ddp_phys_birth == 0) {
1004 ASSERT(ddp->ddp_refcnt == 0);
1005 continue;
1006 }
1007 if (p == DDT_PHYS_DITTO) {
1008 if (ddt_ditto_copies_needed(ddt, dde, NULL) == 0)
1009 ddt_phys_free(ddt, ddk, ddp, txg);
1010 continue;
1011 }
1012 if (ddp->ddp_refcnt == 0)
1013 ddt_phys_free(ddt, ddk, ddp, txg);
1014 total_refcnt += ddp->ddp_refcnt;
1015 }
1016
1017 if (dde->dde_phys[DDT_PHYS_DITTO].ddp_phys_birth != 0)
1018 nclass = DDT_CLASS_DITTO;
1019 else if (total_refcnt > 1)
1020 nclass = DDT_CLASS_DUPLICATE;
1021 else
1022 nclass = DDT_CLASS_UNIQUE;
1023
1024 if (otype != DDT_TYPES &&
1025 (otype != ntype || oclass != nclass || total_refcnt == 0)) {
1026 VERIFY(ddt_object_remove(ddt, otype, oclass, dde, tx) == 0);
1027 ASSERT(ddt_object_lookup(ddt, otype, oclass, dde) == ENOENT);
1028 }
1029
1030 if (total_refcnt != 0) {
1031 dde->dde_type = ntype;
1032 dde->dde_class = nclass;
1033 ddt_stat_update(ddt, dde, 0);
1034 if (!ddt_object_exists(ddt, ntype, nclass))
1035 ddt_object_create(ddt, ntype, nclass, tx);
1036 VERIFY(ddt_object_update(ddt, ntype, nclass, dde, tx) == 0);
1037
1038 /*
1039 * If the class changes, the order that we scan this bp
1040 * changes. If it decreases, we could miss it, so
1041 * scan it right now. (This covers both class changing
1042 * while we are doing ddt_walk(), and when we are
1043 * traversing.)
1044 */
1045 if (nclass < oclass) {
1046 dsl_scan_ddt_entry(dp->dp_scan,
1047 ddt->ddt_checksum, dde, tx);
1048 }
1049 }
1050 }
1051
1052 static void
1053 ddt_sync_table(ddt_t *ddt, dmu_tx_t *tx, uint64_t txg)
1054 {
1055 spa_t *spa = ddt->ddt_spa;
1056 ddt_entry_t *dde;
1057 void *cookie = NULL;
1058
1059 if (avl_numnodes(&ddt->ddt_tree) == 0)
1060 return;
1061
1062 ASSERT(spa->spa_uberblock.ub_version >= SPA_VERSION_DEDUP);
1063
1064 if (spa->spa_ddt_stat_object == 0) {
1065 spa->spa_ddt_stat_object = zap_create_link(ddt->ddt_os,
1066 DMU_OT_DDT_STATS, DMU_POOL_DIRECTORY_OBJECT,
1067 DMU_POOL_DDT_STATS, tx);
1068 }
1069
1070 while ((dde = avl_destroy_nodes(&ddt->ddt_tree, &cookie)) != NULL) {
1071 ddt_sync_entry(ddt, dde, tx, txg);
1072 ddt_free(dde);
1073 }
1074
1075 for (enum ddt_type type = 0; type < DDT_TYPES; type++) {
1076 uint64_t count = 0;
1077 for (enum ddt_class class = 0; class < DDT_CLASSES; class++) {
1078 if (ddt_object_exists(ddt, type, class)) {
1079 ddt_object_sync(ddt, type, class, tx);
1080 count += ddt_object_count(ddt, type, class);
1081 }
1082 }
1083 for (enum ddt_class class = 0; class < DDT_CLASSES; class++) {
1084 if (count == 0 && ddt_object_exists(ddt, type, class))
1085 ddt_object_destroy(ddt, type, class, tx);
1086 }
1087 }
1088
1089 bcopy(ddt->ddt_histogram, &ddt->ddt_histogram_cache,
1090 sizeof (ddt->ddt_histogram));
1091 }
1092
1093 void
1094 ddt_sync(spa_t *spa, uint64_t txg)
1095 {
1096 dmu_tx_t *tx;
1097 zio_t *rio = zio_root(spa, NULL, NULL,
1098 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE);
1099
1100 ASSERT(spa_syncing_txg(spa) == txg);
1101
1102 tx = dmu_tx_create_assigned(spa->spa_dsl_pool, txg);
1103
1104 for (enum zio_checksum c = 0; c < ZIO_CHECKSUM_FUNCTIONS; c++) {
1105 ddt_t *ddt = spa->spa_ddt[c];
1106 if (ddt == NULL)
1107 continue;
1108 ddt_sync_table(ddt, tx, txg);
1109 ddt_repair_table(ddt, rio);
1110 }
1111
1112 (void) zio_wait(rio);
1113
1114 dmu_tx_commit(tx);
1115 }
1116
1117 int
1118 ddt_walk(spa_t *spa, ddt_bookmark_t *ddb, ddt_entry_t *dde)
1119 {
1120 do {
1121 do {
1122 do {
1123 ddt_t *ddt = spa->spa_ddt[ddb->ddb_checksum];
1124 int error = ENOENT;
1125 if (ddt_object_exists(ddt, ddb->ddb_type,
1126 ddb->ddb_class)) {
1127 error = ddt_object_walk(ddt,
1128 ddb->ddb_type, ddb->ddb_class,
1129 &ddb->ddb_cursor, dde);
1130 }
1131 dde->dde_type = ddb->ddb_type;
1132 dde->dde_class = ddb->ddb_class;
1133 if (error == 0)
1134 return (0);
1135 if (error != ENOENT)
1136 return (error);
1137 ddb->ddb_cursor = 0;
1138 } while (++ddb->ddb_checksum < ZIO_CHECKSUM_FUNCTIONS);
1139 ddb->ddb_checksum = 0;
1140 } while (++ddb->ddb_type < DDT_TYPES);
1141 ddb->ddb_type = 0;
1142 } while (++ddb->ddb_class < DDT_CLASSES);
1143
1144 return (SET_ERROR(ENOENT));
1145 }