xref: /freebsd/sys/contrib/openzfs/module/zfs/bpobj.c (revision 61145dc2b94f12f6a47344fb9aac702321880e43)
1 // SPDX-License-Identifier: CDDL-1.0
2 /*
3  * CDDL HEADER START
4  *
5  * The contents of this file are subject to the terms of the
6  * Common Development and Distribution License (the "License").
7  * You may not use this file except in compliance with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or https://opensource.org/licenses/CDDL-1.0.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
24  * Copyright (c) 2011, 2018 by Delphix. All rights reserved.
25  * Copyright (c) 2017 Datto Inc.
26  */
27 
28 #include <sys/bpobj.h>
29 #include <sys/zfs_context.h>
30 #include <sys/zfs_refcount.h>
31 #include <sys/dsl_pool.h>
32 #include <sys/zfeature.h>
33 #include <sys/zap.h>
34 
35 /*
36  * Return an empty bpobj, preferably the empty dummy one (dp_empty_bpobj).
37  */
38 uint64_t
bpobj_alloc_empty(objset_t * os,int blocksize,dmu_tx_t * tx)39 bpobj_alloc_empty(objset_t *os, int blocksize, dmu_tx_t *tx)
40 {
41 	spa_t *spa = dmu_objset_spa(os);
42 	dsl_pool_t *dp = dmu_objset_pool(os);
43 
44 	if (spa_feature_is_enabled(spa, SPA_FEATURE_EMPTY_BPOBJ)) {
45 		if (!spa_feature_is_active(spa, SPA_FEATURE_EMPTY_BPOBJ)) {
46 			ASSERT0(dp->dp_empty_bpobj);
47 			dp->dp_empty_bpobj =
48 			    bpobj_alloc(os, SPA_OLD_MAXBLOCKSIZE, tx);
49 			VERIFY(zap_add(os,
50 			    DMU_POOL_DIRECTORY_OBJECT,
51 			    DMU_POOL_EMPTY_BPOBJ, sizeof (uint64_t), 1,
52 			    &dp->dp_empty_bpobj, tx) == 0);
53 		}
54 		spa_feature_incr(spa, SPA_FEATURE_EMPTY_BPOBJ, tx);
55 		ASSERT(dp->dp_empty_bpobj != 0);
56 		return (dp->dp_empty_bpobj);
57 	} else {
58 		return (bpobj_alloc(os, blocksize, tx));
59 	}
60 }
61 
62 void
bpobj_decr_empty(objset_t * os,dmu_tx_t * tx)63 bpobj_decr_empty(objset_t *os, dmu_tx_t *tx)
64 {
65 	dsl_pool_t *dp = dmu_objset_pool(os);
66 
67 	spa_feature_decr(dmu_objset_spa(os), SPA_FEATURE_EMPTY_BPOBJ, tx);
68 	if (!spa_feature_is_active(dmu_objset_spa(os),
69 	    SPA_FEATURE_EMPTY_BPOBJ)) {
70 		VERIFY3U(0, ==, zap_remove(dp->dp_meta_objset,
71 		    DMU_POOL_DIRECTORY_OBJECT,
72 		    DMU_POOL_EMPTY_BPOBJ, tx));
73 		VERIFY3U(0, ==, dmu_object_free(os, dp->dp_empty_bpobj, tx));
74 		dp->dp_empty_bpobj = 0;
75 	}
76 }
77 
78 uint64_t
bpobj_alloc(objset_t * os,int blocksize,dmu_tx_t * tx)79 bpobj_alloc(objset_t *os, int blocksize, dmu_tx_t *tx)
80 {
81 	int size;
82 
83 	if (spa_version(dmu_objset_spa(os)) < SPA_VERSION_BPOBJ_ACCOUNT)
84 		size = BPOBJ_SIZE_V0;
85 	else if (spa_version(dmu_objset_spa(os)) < SPA_VERSION_DEADLISTS)
86 		size = BPOBJ_SIZE_V1;
87 	else if (!spa_feature_is_active(dmu_objset_spa(os),
88 	    SPA_FEATURE_LIVELIST))
89 		size = BPOBJ_SIZE_V2;
90 	else
91 		size = sizeof (bpobj_phys_t);
92 
93 	return (dmu_object_alloc(os, DMU_OT_BPOBJ, blocksize,
94 	    DMU_OT_BPOBJ_HDR, size, tx));
95 }
96 
97 void
bpobj_free(objset_t * os,uint64_t obj,dmu_tx_t * tx)98 bpobj_free(objset_t *os, uint64_t obj, dmu_tx_t *tx)
99 {
100 	int64_t i;
101 	bpobj_t bpo;
102 	dmu_object_info_t doi;
103 	int epb;
104 	dmu_buf_t *dbuf = NULL;
105 
106 	ASSERT(obj != dmu_objset_pool(os)->dp_empty_bpobj);
107 	VERIFY3U(0, ==, bpobj_open(&bpo, os, obj));
108 
109 	mutex_enter(&bpo.bpo_lock);
110 
111 	if (!bpo.bpo_havesubobj || bpo.bpo_phys->bpo_subobjs == 0)
112 		goto out;
113 
114 	VERIFY3U(0, ==, dmu_object_info(os, bpo.bpo_phys->bpo_subobjs, &doi));
115 	epb = doi.doi_data_block_size / sizeof (uint64_t);
116 
117 	for (i = bpo.bpo_phys->bpo_num_subobjs - 1; i >= 0; i--) {
118 		uint64_t *objarray;
119 		uint64_t offset, blkoff;
120 
121 		offset = i * sizeof (uint64_t);
122 		blkoff = P2PHASE(i, epb);
123 
124 		if (dbuf == NULL || dbuf->db_offset > offset) {
125 			if (dbuf)
126 				dmu_buf_rele(dbuf, FTAG);
127 			VERIFY3U(0, ==, dmu_buf_hold(os,
128 			    bpo.bpo_phys->bpo_subobjs, offset, FTAG, &dbuf, 0));
129 		}
130 
131 		ASSERT3U(offset, >=, dbuf->db_offset);
132 		ASSERT3U(offset, <, dbuf->db_offset + dbuf->db_size);
133 
134 		objarray = dbuf->db_data;
135 		bpobj_free(os, objarray[blkoff], tx);
136 	}
137 	if (dbuf) {
138 		dmu_buf_rele(dbuf, FTAG);
139 		dbuf = NULL;
140 	}
141 	VERIFY3U(0, ==, dmu_object_free(os, bpo.bpo_phys->bpo_subobjs, tx));
142 
143 out:
144 	mutex_exit(&bpo.bpo_lock);
145 	bpobj_close(&bpo);
146 
147 	VERIFY3U(0, ==, dmu_object_free(os, obj, tx));
148 }
149 
150 int
bpobj_open(bpobj_t * bpo,objset_t * os,uint64_t object)151 bpobj_open(bpobj_t *bpo, objset_t *os, uint64_t object)
152 {
153 	dmu_object_info_t doi;
154 	int err;
155 
156 	err = dmu_object_info(os, object, &doi);
157 	if (err)
158 		return (err);
159 
160 	memset(bpo, 0, sizeof (*bpo));
161 	mutex_init(&bpo->bpo_lock, NULL, MUTEX_DEFAULT, NULL);
162 
163 	ASSERT(bpo->bpo_dbuf == NULL);
164 	ASSERT(bpo->bpo_phys == NULL);
165 	ASSERT(object != 0);
166 	ASSERT3U(doi.doi_type, ==, DMU_OT_BPOBJ);
167 	ASSERT3U(doi.doi_bonus_type, ==, DMU_OT_BPOBJ_HDR);
168 
169 	err = dmu_bonus_hold(os, object, bpo, &bpo->bpo_dbuf);
170 	if (err)
171 		return (err);
172 
173 	bpo->bpo_os = os;
174 	bpo->bpo_object = object;
175 	bpo->bpo_epb = doi.doi_data_block_size >> SPA_BLKPTRSHIFT;
176 	bpo->bpo_havecomp = (doi.doi_bonus_size > BPOBJ_SIZE_V0);
177 	bpo->bpo_havesubobj = (doi.doi_bonus_size > BPOBJ_SIZE_V1);
178 	bpo->bpo_havefreed = (doi.doi_bonus_size > BPOBJ_SIZE_V2);
179 	bpo->bpo_phys = bpo->bpo_dbuf->db_data;
180 	return (0);
181 }
182 
183 boolean_t
bpobj_is_open(const bpobj_t * bpo)184 bpobj_is_open(const bpobj_t *bpo)
185 {
186 	return (bpo->bpo_object != 0);
187 }
188 
189 void
bpobj_close(bpobj_t * bpo)190 bpobj_close(bpobj_t *bpo)
191 {
192 	/* Lame workaround for closing a bpobj that was never opened. */
193 	if (bpo->bpo_object == 0)
194 		return;
195 
196 	dmu_buf_rele(bpo->bpo_dbuf, bpo);
197 	if (bpo->bpo_cached_dbuf != NULL)
198 		dmu_buf_rele(bpo->bpo_cached_dbuf, bpo);
199 	bpo->bpo_dbuf = NULL;
200 	bpo->bpo_phys = NULL;
201 	bpo->bpo_cached_dbuf = NULL;
202 	bpo->bpo_object = 0;
203 
204 	mutex_destroy(&bpo->bpo_lock);
205 }
206 
207 static boolean_t
bpobj_is_empty_impl(bpobj_t * bpo)208 bpobj_is_empty_impl(bpobj_t *bpo)
209 {
210 	ASSERT(MUTEX_HELD(&bpo->bpo_lock));
211 	return (bpo->bpo_phys->bpo_num_blkptrs == 0 &&
212 	    (!bpo->bpo_havesubobj || bpo->bpo_phys->bpo_num_subobjs == 0));
213 }
214 
215 boolean_t
bpobj_is_empty(bpobj_t * bpo)216 bpobj_is_empty(bpobj_t *bpo)
217 {
218 	mutex_enter(&bpo->bpo_lock);
219 	boolean_t is_empty = bpobj_is_empty_impl(bpo);
220 	mutex_exit(&bpo->bpo_lock);
221 	return (is_empty);
222 }
223 
224 /*
225  * A recursive iteration of the bpobjs would be nice here but we run the risk
226  * of overflowing function stack space.  Instead, find each subobj and add it
227  * to the head of our list so it can be scanned for subjobjs.  Like a
228  * recursive implementation, the "deepest" subobjs will be freed first.
229  * When a subobj is found to have no additional subojs, free it.
230  */
231 typedef struct bpobj_info {
232 	bpobj_t *bpi_bpo;
233 	/*
234 	 * This object is a subobj of bpi_parent,
235 	 * at bpi_index in its subobj array.
236 	 */
237 	struct bpobj_info *bpi_parent;
238 	uint64_t bpi_index;
239 	/* How many of our subobj's are left to process. */
240 	uint64_t bpi_unprocessed_subobjs;
241 	/* True after having visited this bpo's directly referenced BPs. */
242 	boolean_t bpi_visited;
243 	list_node_t bpi_node;
244 } bpobj_info_t;
245 
246 static bpobj_info_t *
bpi_alloc(bpobj_t * bpo,bpobj_info_t * parent,uint64_t index)247 bpi_alloc(bpobj_t *bpo, bpobj_info_t *parent, uint64_t index)
248 {
249 	bpobj_info_t *bpi = kmem_zalloc(sizeof (bpobj_info_t), KM_SLEEP);
250 	bpi->bpi_bpo = bpo;
251 	bpi->bpi_parent = parent;
252 	bpi->bpi_index = index;
253 	if (bpo->bpo_havesubobj && bpo->bpo_phys->bpo_subobjs != 0) {
254 		bpi->bpi_unprocessed_subobjs = bpo->bpo_phys->bpo_num_subobjs;
255 	}
256 	return (bpi);
257 }
258 
259 /*
260  * Update bpobj and all of its parents with new space accounting.
261  */
262 static void
propagate_space_reduction(bpobj_info_t * bpi,int64_t freed,int64_t comp_freed,int64_t uncomp_freed,dmu_tx_t * tx)263 propagate_space_reduction(bpobj_info_t *bpi, int64_t freed,
264     int64_t comp_freed, int64_t uncomp_freed, dmu_tx_t *tx)
265 {
266 
267 	for (; bpi != NULL; bpi = bpi->bpi_parent) {
268 		bpobj_t *p = bpi->bpi_bpo;
269 		ASSERT(dmu_buf_is_dirty(p->bpo_dbuf, tx));
270 		p->bpo_phys->bpo_bytes -= freed;
271 		ASSERT3S(p->bpo_phys->bpo_bytes, >=, 0);
272 		if (p->bpo_havecomp) {
273 			p->bpo_phys->bpo_comp -= comp_freed;
274 			p->bpo_phys->bpo_uncomp -= uncomp_freed;
275 		}
276 	}
277 }
278 
279 static int
bpobj_iterate_blkptrs(bpobj_info_t * bpi,bpobj_itor_t func,void * arg,int64_t start,dmu_tx_t * tx,boolean_t free)280 bpobj_iterate_blkptrs(bpobj_info_t *bpi, bpobj_itor_t func, void *arg,
281     int64_t start, dmu_tx_t *tx, boolean_t free)
282 {
283 	int err = 0;
284 	int64_t freed = 0, comp_freed = 0, uncomp_freed = 0;
285 	dmu_buf_t *dbuf = NULL;
286 	bpobj_t *bpo = bpi->bpi_bpo;
287 
288 	int64_t i = bpo->bpo_phys->bpo_num_blkptrs - 1;
289 	uint64_t pe = P2ALIGN_TYPED(i, bpo->bpo_epb, uint64_t) *
290 	    sizeof (blkptr_t);
291 	uint64_t ps = start * sizeof (blkptr_t);
292 	uint64_t pb = MAX((pe > dmu_prefetch_max) ? pe - dmu_prefetch_max : 0,
293 	    ps);
294 	if (pe > pb) {
295 		dmu_prefetch(bpo->bpo_os, bpo->bpo_object, 0, pb, pe - pb,
296 		    ZIO_PRIORITY_ASYNC_READ);
297 	}
298 	for (; i >= start; i--) {
299 		uint64_t offset = i * sizeof (blkptr_t);
300 		uint64_t blkoff = P2PHASE(i, bpo->bpo_epb);
301 
302 		if (dbuf == NULL || dbuf->db_offset > offset) {
303 			if (dbuf)
304 				dmu_buf_rele(dbuf, FTAG);
305 			err = dmu_buf_hold(bpo->bpo_os, bpo->bpo_object,
306 			    offset, FTAG, &dbuf, DMU_READ_NO_PREFETCH);
307 			if (err)
308 				break;
309 			pe = pb;
310 			pb = MAX((dbuf->db_offset > dmu_prefetch_max) ?
311 			    dbuf->db_offset - dmu_prefetch_max : 0, ps);
312 			if (pe > pb) {
313 				dmu_prefetch(bpo->bpo_os, bpo->bpo_object, 0,
314 				    pb, pe - pb, ZIO_PRIORITY_ASYNC_READ);
315 			}
316 		}
317 
318 		ASSERT3U(offset, >=, dbuf->db_offset);
319 		ASSERT3U(offset, <, dbuf->db_offset + dbuf->db_size);
320 
321 		blkptr_t *bparray = dbuf->db_data;
322 		blkptr_t *bp = &bparray[blkoff];
323 
324 		boolean_t bp_freed = BP_GET_FREE(bp);
325 		err = func(arg, bp, bp_freed, tx);
326 		if (err)
327 			break;
328 
329 		if (free) {
330 			int sign = bp_freed ? -1 : +1;
331 			spa_t *spa = dmu_objset_spa(bpo->bpo_os);
332 			freed += sign * bp_get_dsize_sync(spa, bp);
333 			comp_freed += sign * BP_GET_PSIZE(bp);
334 			uncomp_freed += sign * BP_GET_UCSIZE(bp);
335 			ASSERT(dmu_buf_is_dirty(bpo->bpo_dbuf, tx));
336 			bpo->bpo_phys->bpo_num_blkptrs--;
337 			ASSERT3S(bpo->bpo_phys->bpo_num_blkptrs, >=, 0);
338 			if (bp_freed) {
339 				ASSERT(bpo->bpo_havefreed);
340 				bpo->bpo_phys->bpo_num_freed--;
341 				ASSERT3S(bpo->bpo_phys->bpo_num_freed, >=, 0);
342 			}
343 		}
344 	}
345 	if (free) {
346 		propagate_space_reduction(bpi, freed, comp_freed,
347 		    uncomp_freed, tx);
348 		VERIFY0(dmu_free_range(bpo->bpo_os,
349 		    bpo->bpo_object,
350 		    bpo->bpo_phys->bpo_num_blkptrs * sizeof (blkptr_t),
351 		    DMU_OBJECT_END, tx));
352 	}
353 	if (dbuf) {
354 		dmu_buf_rele(dbuf, FTAG);
355 		dbuf = NULL;
356 	}
357 	return (err);
358 }
359 
360 /*
361  * Given an initial bpo, start by freeing the BPs that are directly referenced
362  * by that bpo. If the bpo has subobjs, read in its last subobj and push the
363  * subobj to our stack. By popping items off our stack, eventually we will
364  * encounter a bpo that has no subobjs.  We can free its bpobj_info_t, and if
365  * requested also free the now-empty bpo from disk and decrement
366  * its parent's subobj count. We continue popping each subobj from our stack,
367  * visiting its last subobj until they too have no more subobjs, and so on.
368  */
369 static int
bpobj_iterate_impl(bpobj_t * initial_bpo,bpobj_itor_t func,void * arg,dmu_tx_t * tx,boolean_t free,uint64_t * bpobj_size)370 bpobj_iterate_impl(bpobj_t *initial_bpo, bpobj_itor_t func, void *arg,
371     dmu_tx_t *tx, boolean_t free, uint64_t *bpobj_size)
372 {
373 	list_t stack;
374 	bpobj_info_t *bpi;
375 	int err = 0;
376 
377 	/*
378 	 * Create a "stack" for us to work with without worrying about
379 	 * stack overflows. Initialize it with the initial_bpo.
380 	 */
381 	list_create(&stack, sizeof (bpobj_info_t),
382 	    offsetof(bpobj_info_t, bpi_node));
383 	mutex_enter(&initial_bpo->bpo_lock);
384 
385 	if (bpobj_size != NULL)
386 		*bpobj_size = initial_bpo->bpo_phys->bpo_num_blkptrs;
387 
388 	list_insert_head(&stack, bpi_alloc(initial_bpo, NULL, 0));
389 
390 	while ((bpi = list_head(&stack)) != NULL) {
391 		bpobj_t *bpo = bpi->bpi_bpo;
392 
393 		ASSERT3P(bpo, !=, NULL);
394 		ASSERT(MUTEX_HELD(&bpo->bpo_lock));
395 		ASSERT(bpobj_is_open(bpo));
396 
397 		if (free)
398 			dmu_buf_will_dirty(bpo->bpo_dbuf, tx);
399 
400 		if (bpi->bpi_visited == B_FALSE) {
401 			err = bpobj_iterate_blkptrs(bpi, func, arg, 0, tx,
402 			    free);
403 			bpi->bpi_visited = B_TRUE;
404 			if (err != 0)
405 				break;
406 		}
407 		/*
408 		 * We've finished with this bpo's directly-referenced BP's and
409 		 * it has no more unprocessed subobjs. We can free its
410 		 * bpobj_info_t (unless it is the topmost, initial_bpo).
411 		 * If we are freeing from disk, we can also do that.
412 		 */
413 		if (bpi->bpi_unprocessed_subobjs == 0) {
414 			/*
415 			 * If there are no entries, there should
416 			 * be no bytes.
417 			 */
418 			if (bpobj_is_empty_impl(bpo)) {
419 				ASSERT0(bpo->bpo_phys->bpo_bytes);
420 				ASSERT0(bpo->bpo_phys->bpo_comp);
421 				ASSERT0(bpo->bpo_phys->bpo_uncomp);
422 			}
423 
424 			/* The initial_bpo has no parent and is not closed. */
425 			if (bpi->bpi_parent != NULL) {
426 				if (free) {
427 					bpobj_t *p = bpi->bpi_parent->bpi_bpo;
428 
429 					ASSERT0(bpo->bpo_phys->bpo_num_blkptrs);
430 					ASSERT3U(p->bpo_phys->bpo_num_subobjs,
431 					    >, 0);
432 					ASSERT3U(bpi->bpi_index, ==,
433 					    p->bpo_phys->bpo_num_subobjs - 1);
434 					ASSERT(dmu_buf_is_dirty(bpo->bpo_dbuf,
435 					    tx));
436 
437 					p->bpo_phys->bpo_num_subobjs--;
438 
439 					VERIFY0(dmu_free_range(p->bpo_os,
440 					    p->bpo_phys->bpo_subobjs,
441 					    bpi->bpi_index * sizeof (uint64_t),
442 					    sizeof (uint64_t), tx));
443 
444 					/* eliminate the empty subobj list */
445 					if (bpo->bpo_havesubobj &&
446 					    bpo->bpo_phys->bpo_subobjs != 0) {
447 						ASSERT0(bpo->bpo_phys->
448 						    bpo_num_subobjs);
449 						err = dmu_object_free(
450 						    bpo->bpo_os,
451 						    bpo->bpo_phys->bpo_subobjs,
452 						    tx);
453 						if (err)
454 							break;
455 						bpo->bpo_phys->bpo_subobjs = 0;
456 					}
457 					err = dmu_object_free(p->bpo_os,
458 					    bpo->bpo_object, tx);
459 					if (err)
460 						break;
461 				}
462 
463 				mutex_exit(&bpo->bpo_lock);
464 				bpobj_close(bpo);
465 				kmem_free(bpo, sizeof (bpobj_t));
466 			} else {
467 				mutex_exit(&bpo->bpo_lock);
468 			}
469 
470 			/*
471 			 * Finished processing this bpo. Unlock, and free
472 			 * our "stack" info.
473 			 */
474 			list_remove_head(&stack);
475 			kmem_free(bpi, sizeof (bpobj_info_t));
476 		} else {
477 			/*
478 			 * We have unprocessed subobjs. Process the next one.
479 			 */
480 			ASSERT(bpo->bpo_havecomp);
481 			ASSERT3P(bpobj_size, ==, NULL);
482 
483 			/* Add the last subobj to stack. */
484 			int64_t i = bpi->bpi_unprocessed_subobjs - 1;
485 			uint64_t offset = i * sizeof (uint64_t);
486 
487 			uint64_t subobj;
488 			err = dmu_read(bpo->bpo_os, bpo->bpo_phys->bpo_subobjs,
489 			    offset, sizeof (uint64_t), &subobj,
490 			    DMU_READ_NO_PREFETCH);
491 			if (err)
492 				break;
493 
494 			bpobj_t *subbpo = kmem_alloc(sizeof (bpobj_t),
495 			    KM_SLEEP);
496 			err = bpobj_open(subbpo, bpo->bpo_os, subobj);
497 			if (err) {
498 				kmem_free(subbpo, sizeof (bpobj_t));
499 				break;
500 			}
501 
502 			if (subbpo->bpo_havesubobj &&
503 			    subbpo->bpo_phys->bpo_subobjs != 0) {
504 				dmu_prefetch(subbpo->bpo_os,
505 				    subbpo->bpo_phys->bpo_subobjs, 0, 0, 0,
506 				    ZIO_PRIORITY_ASYNC_READ);
507 			}
508 
509 			list_insert_head(&stack, bpi_alloc(subbpo, bpi, i));
510 			mutex_enter(&subbpo->bpo_lock);
511 			bpi->bpi_unprocessed_subobjs--;
512 		}
513 	}
514 	/*
515 	 * Cleanup anything left on the "stack" after we left the loop.
516 	 * Every bpo on the stack is locked so we must remember to undo
517 	 * that now (in LIFO order).
518 	 */
519 	while ((bpi = list_remove_head(&stack)) != NULL) {
520 		bpobj_t *bpo = bpi->bpi_bpo;
521 		ASSERT(err != 0);
522 		ASSERT3P(bpo, !=, NULL);
523 
524 		mutex_exit(&bpo->bpo_lock);
525 
526 		/* do not free the initial_bpo */
527 		if (bpi->bpi_parent != NULL) {
528 			bpobj_close(bpi->bpi_bpo);
529 			kmem_free(bpi->bpi_bpo, sizeof (bpobj_t));
530 		}
531 		kmem_free(bpi, sizeof (bpobj_info_t));
532 	}
533 
534 	list_destroy(&stack);
535 
536 	return (err);
537 }
538 
539 /*
540  * Iterate and remove the entries.  If func returns nonzero, iteration
541  * will stop and that entry will not be removed.
542  */
543 int
bpobj_iterate(bpobj_t * bpo,bpobj_itor_t func,void * arg,dmu_tx_t * tx)544 bpobj_iterate(bpobj_t *bpo, bpobj_itor_t func, void *arg, dmu_tx_t *tx)
545 {
546 	return (bpobj_iterate_impl(bpo, func, arg, tx, B_TRUE, NULL));
547 }
548 
549 /*
550  * Iterate the entries.  If func returns nonzero, iteration will stop.
551  *
552  * If there are no subobjs:
553  *
554  * *bpobj_size can be used to return the number of block pointers in the
555  * bpobj.  Note that this may be different from the number of block pointers
556  * that are iterated over, if iteration is terminated early (e.g. by the func
557  * returning nonzero).
558  *
559  * If there are concurrent (or subsequent) modifications to the bpobj then the
560  * returned *bpobj_size can be passed as "start" to
561  * livelist_bpobj_iterate_from_nofree() to iterate the newly added entries.
562  */
563 int
bpobj_iterate_nofree(bpobj_t * bpo,bpobj_itor_t func,void * arg,uint64_t * bpobj_size)564 bpobj_iterate_nofree(bpobj_t *bpo, bpobj_itor_t func, void *arg,
565     uint64_t *bpobj_size)
566 {
567 	return (bpobj_iterate_impl(bpo, func, arg, NULL, B_FALSE, bpobj_size));
568 }
569 
570 /*
571  * Iterate over the blkptrs in the bpobj beginning at index start. If func
572  * returns nonzero, iteration will stop. This is a livelist specific function
573  * since it assumes that there are no subobjs present.
574  */
575 int
livelist_bpobj_iterate_from_nofree(bpobj_t * bpo,bpobj_itor_t func,void * arg,int64_t start)576 livelist_bpobj_iterate_from_nofree(bpobj_t *bpo, bpobj_itor_t func, void *arg,
577     int64_t start)
578 {
579 	if (bpo->bpo_havesubobj)
580 		VERIFY0(bpo->bpo_phys->bpo_subobjs);
581 	bpobj_info_t *bpi = bpi_alloc(bpo, NULL, 0);
582 	int err = bpobj_iterate_blkptrs(bpi, func, arg, start, NULL, B_FALSE);
583 	kmem_free(bpi, sizeof (bpobj_info_t));
584 	return (err);
585 }
586 
587 /*
588  * Logically add subobj's contents to the parent bpobj.
589  *
590  * In the most general case, this is accomplished in constant time by adding
591  * a reference to subobj.  This case is used when enqueuing a large subobj:
592  * +--------------+                        +--------------+
593  * | bpobj        |----------------------->| subobj list  |
594  * +----+----+----+----+----+              +-----+-----+--+--+
595  * | bp | bp | bp | bp | bp |              | obj | obj | obj |
596  * +----+----+----+----+----+              +-----+-----+-----+
597  *
598  * +--------------+                        +--------------+
599  * | sub-bpobj    |----------------------> | subsubobj    |
600  * +----+----+----+----+---------+----+    +-----+-----+--+--------+-----+
601  * | bp | bp | bp | bp |   ...   | bp |    | obj | obj |    ...    | obj |
602  * +----+----+----+----+---------+----+    +-----+-----+-----------+-----+
603  *
604  * Result: sub-bpobj added to parent's subobj list.
605  * +--------------+                        +--------------+
606  * | bpobj        |----------------------->| subobj list  |
607  * +----+----+----+----+----+              +-----+-----+--+--+-----+
608  * | bp | bp | bp | bp | bp |              | obj | obj | obj | OBJ |
609  * +----+----+----+----+----+              +-----+-----+-----+--|--+
610  *                                                              |
611  *       /-----------------------------------------------------/
612  *       v
613  * +--------------+                        +--------------+
614  * | sub-bpobj    |----------------------> | subsubobj    |
615  * +----+----+----+----+---------+----+    +-----+-----+--+--------+-----+
616  * | bp | bp | bp | bp |   ...   | bp |    | obj | obj |    ...    | obj |
617  * +----+----+----+----+---------+----+    +-----+-----+-----------+-----+
618  *
619  *
620  * In a common case, the subobj is small: its bp's and its list of subobj's
621  * are each stored in a single block.  In this case we copy the subobj's
622  * contents to the parent:
623  * +--------------+                        +--------------+
624  * | bpobj        |----------------------->| subobj list  |
625  * +----+----+----+----+----+              +-----+-----+--+--+
626  * | bp | bp | bp | bp | bp |              | obj | obj | obj |
627  * +----+----+----+----+----+              +-----+-----+-----+
628  *                          ^                                ^
629  * +--------------+         |              +--------------+  |
630  * | sub-bpobj    |---------^------------> | subsubobj    |  ^
631  * +----+----+----+         |              +-----+-----+--+  |
632  * | BP | BP |-->-->-->-->-/               | OBJ | OBJ |-->-/
633  * +----+----+                             +-----+-----+
634  *
635  * Result: subobj destroyed, contents copied to parent:
636  * +--------------+                        +--------------+
637  * | bpobj        |----------------------->| subobj list  |
638  * +----+----+----+----+----+----+----+    +-----+-----+--+--+-----+-----+
639  * | bp | bp | bp | bp | bp | BP | BP |    | obj | obj | obj | OBJ | OBJ |
640  * +----+----+----+----+----+----+----+    +-----+-----+-----+-----+-----+
641  *
642  *
643  * If the subobj has many BP's but few subobj's, we can copy the sub-subobj's
644  * but retain the sub-bpobj:
645  * +--------------+                        +--------------+
646  * | bpobj        |----------------------->| subobj list  |
647  * +----+----+----+----+----+              +-----+-----+--+--+
648  * | bp | bp | bp | bp | bp |              | obj | obj | obj |
649  * +----+----+----+----+----+              +-----+-----+-----+
650  *                                                           ^
651  * +--------------+                        +--------------+  |
652  * | sub-bpobj    |----------------------> | subsubobj    |  ^
653  * +----+----+----+----+---------+----+    +-----+-----+--+  |
654  * | bp | bp | bp | bp |   ...   | bp |    | OBJ | OBJ |-->-/
655  * +----+----+----+----+---------+----+    +-----+-----+
656  *
657  * Result: sub-sub-bpobjs and subobj added to parent's subobj list.
658  * +--------------+                     +--------------+
659  * | bpobj        |-------------------->| subobj list  |
660  * +----+----+----+----+----+           +-----+-----+--+--+-----+-----+------+
661  * | bp | bp | bp | bp | bp |           | obj | obj | obj | OBJ | OBJ | OBJ* |
662  * +----+----+----+----+----+           +-----+-----+-----+-----+-----+--|---+
663  *                                                                       |
664  *       /--------------------------------------------------------------/
665  *       v
666  * +--------------+
667  * | sub-bpobj    |
668  * +----+----+----+----+---------+----+
669  * | bp | bp | bp | bp |   ...   | bp |
670  * +----+----+----+----+---------+----+
671  */
672 void
bpobj_enqueue_subobj(bpobj_t * bpo,uint64_t subobj,dmu_tx_t * tx)673 bpobj_enqueue_subobj(bpobj_t *bpo, uint64_t subobj, dmu_tx_t *tx)
674 {
675 	bpobj_t subbpo;
676 	uint64_t used, comp, uncomp, subsubobjs;
677 	boolean_t copy_subsub = B_TRUE;
678 	boolean_t copy_bps = B_TRUE;
679 
680 	ASSERT(bpobj_is_open(bpo));
681 	ASSERT(subobj != 0);
682 	ASSERT(bpo->bpo_havesubobj);
683 	ASSERT(bpo->bpo_havecomp);
684 	ASSERT(bpo->bpo_object != dmu_objset_pool(bpo->bpo_os)->dp_empty_bpobj);
685 
686 	if (subobj == dmu_objset_pool(bpo->bpo_os)->dp_empty_bpobj) {
687 		bpobj_decr_empty(bpo->bpo_os, tx);
688 		return;
689 	}
690 
691 	VERIFY3U(0, ==, bpobj_open(&subbpo, bpo->bpo_os, subobj));
692 	if (bpobj_is_empty(&subbpo)) {
693 		/* No point in having an empty subobj. */
694 		bpobj_close(&subbpo);
695 		bpobj_free(bpo->bpo_os, subobj, tx);
696 		return;
697 	}
698 	VERIFY3U(0, ==, bpobj_space(&subbpo, &used, &comp, &uncomp));
699 
700 	mutex_enter(&bpo->bpo_lock);
701 	dmu_buf_will_dirty(bpo->bpo_dbuf, tx);
702 
703 	dmu_object_info_t doi;
704 
705 	if (bpo->bpo_phys->bpo_subobjs != 0) {
706 		ASSERT0(dmu_object_info(bpo->bpo_os, bpo->bpo_phys->bpo_subobjs,
707 		    &doi));
708 		ASSERT3U(doi.doi_type, ==, DMU_OT_BPOBJ_SUBOBJ);
709 	}
710 
711 	/*
712 	 * If subobj has only one block of subobjs, then move subobj's
713 	 * subobjs to bpo's subobj list directly.  This reduces recursion in
714 	 * bpobj_iterate due to nested subobjs.
715 	 */
716 	subsubobjs = subbpo.bpo_phys->bpo_subobjs;
717 	if (subsubobjs != 0) {
718 		VERIFY0(dmu_object_info(bpo->bpo_os, subsubobjs, &doi));
719 		if (doi.doi_max_offset > doi.doi_data_block_size) {
720 			copy_subsub = B_FALSE;
721 		}
722 	}
723 
724 	/*
725 	 * If, in addition to having only one block of subobj's, subobj has
726 	 * only one block of bp's, then move subobj's bp's to bpo's bp list
727 	 * directly. This reduces recursion in bpobj_iterate due to nested
728 	 * subobjs.
729 	 */
730 	VERIFY3U(0, ==, dmu_object_info(bpo->bpo_os, subobj, &doi));
731 	if (doi.doi_max_offset > doi.doi_data_block_size || !copy_subsub) {
732 		copy_bps = B_FALSE;
733 	}
734 
735 	if (copy_subsub && subsubobjs != 0) {
736 		dmu_buf_t *subdb;
737 		uint64_t numsubsub = subbpo.bpo_phys->bpo_num_subobjs;
738 
739 		VERIFY0(dmu_buf_hold(bpo->bpo_os, subsubobjs,
740 		    0, FTAG, &subdb, 0));
741 		/*
742 		 * Make sure that we are not asking dmu_write()
743 		 * to write more data than we have in our buffer.
744 		 */
745 		VERIFY3U(subdb->db_size, >=,
746 		    numsubsub * sizeof (subobj));
747 		if (bpo->bpo_phys->bpo_subobjs == 0) {
748 			bpo->bpo_phys->bpo_subobjs =
749 			    dmu_object_alloc(bpo->bpo_os,
750 			    DMU_OT_BPOBJ_SUBOBJ, SPA_OLD_MAXBLOCKSIZE,
751 			    DMU_OT_NONE, 0, tx);
752 		}
753 		dmu_write(bpo->bpo_os, bpo->bpo_phys->bpo_subobjs,
754 		    bpo->bpo_phys->bpo_num_subobjs * sizeof (subobj),
755 		    numsubsub * sizeof (subobj), subdb->db_data, tx);
756 		dmu_buf_rele(subdb, FTAG);
757 		bpo->bpo_phys->bpo_num_subobjs += numsubsub;
758 
759 		dmu_buf_will_dirty(subbpo.bpo_dbuf, tx);
760 		subbpo.bpo_phys->bpo_subobjs = 0;
761 		VERIFY0(dmu_object_free(bpo->bpo_os, subsubobjs, tx));
762 	}
763 
764 	if (copy_bps) {
765 		dmu_buf_t *bps;
766 		uint64_t numbps = subbpo.bpo_phys->bpo_num_blkptrs;
767 
768 		ASSERT(copy_subsub);
769 		VERIFY0(dmu_buf_hold(bpo->bpo_os, subobj,
770 		    0, FTAG, &bps, 0));
771 
772 		/*
773 		 * Make sure that we are not asking dmu_write()
774 		 * to write more data than we have in our buffer.
775 		 */
776 		VERIFY3U(bps->db_size, >=, numbps * sizeof (blkptr_t));
777 		dmu_write(bpo->bpo_os, bpo->bpo_object,
778 		    bpo->bpo_phys->bpo_num_blkptrs * sizeof (blkptr_t),
779 		    numbps * sizeof (blkptr_t),
780 		    bps->db_data, tx);
781 		dmu_buf_rele(bps, FTAG);
782 		bpo->bpo_phys->bpo_num_blkptrs += numbps;
783 
784 		bpobj_close(&subbpo);
785 		VERIFY0(dmu_object_free(bpo->bpo_os, subobj, tx));
786 	} else {
787 		bpobj_close(&subbpo);
788 		if (bpo->bpo_phys->bpo_subobjs == 0) {
789 			bpo->bpo_phys->bpo_subobjs =
790 			    dmu_object_alloc(bpo->bpo_os,
791 			    DMU_OT_BPOBJ_SUBOBJ, SPA_OLD_MAXBLOCKSIZE,
792 			    DMU_OT_NONE, 0, tx);
793 		}
794 
795 		dmu_write(bpo->bpo_os, bpo->bpo_phys->bpo_subobjs,
796 		    bpo->bpo_phys->bpo_num_subobjs * sizeof (subobj),
797 		    sizeof (subobj), &subobj, tx);
798 		bpo->bpo_phys->bpo_num_subobjs++;
799 	}
800 
801 	bpo->bpo_phys->bpo_bytes += used;
802 	bpo->bpo_phys->bpo_comp += comp;
803 	bpo->bpo_phys->bpo_uncomp += uncomp;
804 	mutex_exit(&bpo->bpo_lock);
805 
806 }
807 
808 /*
809  * Prefetch metadata required for bpobj_enqueue_subobj().
810  */
811 void
bpobj_prefetch_subobj(bpobj_t * bpo,uint64_t subobj)812 bpobj_prefetch_subobj(bpobj_t *bpo, uint64_t subobj)
813 {
814 	dmu_object_info_t doi;
815 	bpobj_t subbpo;
816 	uint64_t subsubobjs;
817 	boolean_t copy_subsub = B_TRUE;
818 	boolean_t copy_bps = B_TRUE;
819 
820 	ASSERT(bpobj_is_open(bpo));
821 	ASSERT(subobj != 0);
822 
823 	if (subobj == dmu_objset_pool(bpo->bpo_os)->dp_empty_bpobj)
824 		return;
825 
826 	if (bpobj_open(&subbpo, bpo->bpo_os, subobj) != 0)
827 		return;
828 	if (bpobj_is_empty(&subbpo)) {
829 		bpobj_close(&subbpo);
830 		return;
831 	}
832 	subsubobjs = subbpo.bpo_phys->bpo_subobjs;
833 	bpobj_close(&subbpo);
834 
835 	if (subsubobjs != 0) {
836 		if (dmu_object_info(bpo->bpo_os, subsubobjs, &doi) != 0)
837 			return;
838 		if (doi.doi_max_offset > doi.doi_data_block_size)
839 			copy_subsub = B_FALSE;
840 	}
841 
842 	if (dmu_object_info(bpo->bpo_os, subobj, &doi) != 0)
843 		return;
844 	if (doi.doi_max_offset > doi.doi_data_block_size || !copy_subsub)
845 		copy_bps = B_FALSE;
846 
847 	if (copy_subsub && subsubobjs != 0) {
848 		if (bpo->bpo_phys->bpo_subobjs) {
849 			dmu_prefetch(bpo->bpo_os, bpo->bpo_phys->bpo_subobjs, 0,
850 			    bpo->bpo_phys->bpo_num_subobjs * sizeof (subobj), 1,
851 			    ZIO_PRIORITY_ASYNC_READ);
852 		}
853 		dmu_prefetch(bpo->bpo_os, subsubobjs, 0, 0, 1,
854 		    ZIO_PRIORITY_ASYNC_READ);
855 	}
856 
857 	if (copy_bps) {
858 		dmu_prefetch(bpo->bpo_os, bpo->bpo_object, 0,
859 		    bpo->bpo_phys->bpo_num_blkptrs * sizeof (blkptr_t), 1,
860 		    ZIO_PRIORITY_ASYNC_READ);
861 		dmu_prefetch(bpo->bpo_os, subobj, 0, 0, 1,
862 		    ZIO_PRIORITY_ASYNC_READ);
863 	} else if (bpo->bpo_phys->bpo_subobjs) {
864 		dmu_prefetch(bpo->bpo_os, bpo->bpo_phys->bpo_subobjs, 0,
865 		    bpo->bpo_phys->bpo_num_subobjs * sizeof (subobj), 1,
866 		    ZIO_PRIORITY_ASYNC_READ);
867 	}
868 }
869 
870 void
bpobj_enqueue(bpobj_t * bpo,const blkptr_t * bp,boolean_t bp_freed,dmu_tx_t * tx)871 bpobj_enqueue(bpobj_t *bpo, const blkptr_t *bp, boolean_t bp_freed,
872     dmu_tx_t *tx)
873 {
874 	blkptr_t stored_bp = *bp;
875 	uint64_t offset;
876 	int blkoff;
877 	blkptr_t *bparray;
878 
879 	ASSERT(bpobj_is_open(bpo));
880 	ASSERT(!BP_IS_HOLE(bp));
881 	ASSERT(bpo->bpo_object != dmu_objset_pool(bpo->bpo_os)->dp_empty_bpobj);
882 
883 	if (BP_IS_EMBEDDED(bp)) {
884 		/*
885 		 * The bpobj will compress better without the payload.
886 		 *
887 		 * Note that we store EMBEDDED bp's because they have an
888 		 * uncompressed size, which must be accounted for.  An
889 		 * alternative would be to add their size to bpo_uncomp
890 		 * without storing the bp, but that would create additional
891 		 * complications: bpo_uncomp would be inconsistent with the
892 		 * set of BP's stored, and bpobj_iterate() wouldn't visit
893 		 * all the space accounted for in the bpobj.
894 		 */
895 		memset(&stored_bp, 0, sizeof (stored_bp));
896 		stored_bp.blk_prop = bp->blk_prop;
897 		BP_SET_LOGICAL_BIRTH(&stored_bp, BP_GET_LOGICAL_BIRTH(bp));
898 	} else if (!BP_GET_DEDUP(bp)) {
899 		/* The bpobj will compress better without the checksum */
900 		memset(&stored_bp.blk_cksum, 0, sizeof (stored_bp.blk_cksum));
901 	}
902 
903 	stored_bp.blk_fill = 0;
904 	BP_SET_FREE(&stored_bp, bp_freed);
905 
906 	mutex_enter(&bpo->bpo_lock);
907 
908 	offset = bpo->bpo_phys->bpo_num_blkptrs * sizeof (stored_bp);
909 	blkoff = P2PHASE(bpo->bpo_phys->bpo_num_blkptrs, bpo->bpo_epb);
910 
911 	if (bpo->bpo_cached_dbuf == NULL ||
912 	    offset < bpo->bpo_cached_dbuf->db_offset ||
913 	    offset >= bpo->bpo_cached_dbuf->db_offset +
914 	    bpo->bpo_cached_dbuf->db_size) {
915 		if (bpo->bpo_cached_dbuf)
916 			dmu_buf_rele(bpo->bpo_cached_dbuf, bpo);
917 		VERIFY3U(0, ==, dmu_buf_hold(bpo->bpo_os, bpo->bpo_object,
918 		    offset, bpo, &bpo->bpo_cached_dbuf, 0));
919 		ASSERT3P(bpo->bpo_cached_dbuf, !=, NULL);
920 	}
921 
922 	dmu_buf_will_dirty(bpo->bpo_cached_dbuf, tx);
923 	bparray = bpo->bpo_cached_dbuf->db_data;
924 	bparray[blkoff] = stored_bp;
925 
926 	dmu_buf_will_dirty(bpo->bpo_dbuf, tx);
927 	bpo->bpo_phys->bpo_num_blkptrs++;
928 	int sign = bp_freed ? -1 : +1;
929 	bpo->bpo_phys->bpo_bytes += sign *
930 	    bp_get_dsize_sync(dmu_objset_spa(bpo->bpo_os), bp);
931 	if (bpo->bpo_havecomp) {
932 		bpo->bpo_phys->bpo_comp += sign * BP_GET_PSIZE(bp);
933 		bpo->bpo_phys->bpo_uncomp += sign * BP_GET_UCSIZE(bp);
934 	}
935 	if (bp_freed) {
936 		ASSERT(bpo->bpo_havefreed);
937 		bpo->bpo_phys->bpo_num_freed++;
938 	}
939 	mutex_exit(&bpo->bpo_lock);
940 }
941 
942 struct space_range_arg {
943 	spa_t *spa;
944 	uint64_t mintxg;
945 	uint64_t maxtxg;
946 	uint64_t used;
947 	uint64_t comp;
948 	uint64_t uncomp;
949 };
950 
951 static int
space_range_cb(void * arg,const blkptr_t * bp,boolean_t bp_freed,dmu_tx_t * tx)952 space_range_cb(void *arg, const blkptr_t *bp, boolean_t bp_freed, dmu_tx_t *tx)
953 {
954 	(void) bp_freed, (void) tx;
955 	struct space_range_arg *sra = arg;
956 
957 	if (BP_GET_LOGICAL_BIRTH(bp) > sra->mintxg &&
958 	    BP_GET_LOGICAL_BIRTH(bp) <= sra->maxtxg) {
959 		if (dsl_pool_sync_context(spa_get_dsl(sra->spa)))
960 			sra->used += bp_get_dsize_sync(sra->spa, bp);
961 		else
962 			sra->used += bp_get_dsize(sra->spa, bp);
963 		sra->comp += BP_GET_PSIZE(bp);
964 		sra->uncomp += BP_GET_UCSIZE(bp);
965 	}
966 	return (0);
967 }
968 
969 int
bpobj_space(bpobj_t * bpo,uint64_t * usedp,uint64_t * compp,uint64_t * uncompp)970 bpobj_space(bpobj_t *bpo, uint64_t *usedp, uint64_t *compp, uint64_t *uncompp)
971 {
972 	ASSERT(bpobj_is_open(bpo));
973 	mutex_enter(&bpo->bpo_lock);
974 
975 	*usedp = bpo->bpo_phys->bpo_bytes;
976 	if (bpo->bpo_havecomp) {
977 		*compp = bpo->bpo_phys->bpo_comp;
978 		*uncompp = bpo->bpo_phys->bpo_uncomp;
979 		mutex_exit(&bpo->bpo_lock);
980 		return (0);
981 	} else {
982 		mutex_exit(&bpo->bpo_lock);
983 		return (bpobj_space_range(bpo, 0, UINT64_MAX,
984 		    usedp, compp, uncompp));
985 	}
986 }
987 
988 /*
989  * Return the amount of space in the bpobj which is:
990  * mintxg < logical birth <= maxtxg
991  */
992 int
bpobj_space_range(bpobj_t * bpo,uint64_t mintxg,uint64_t maxtxg,uint64_t * usedp,uint64_t * compp,uint64_t * uncompp)993 bpobj_space_range(bpobj_t *bpo, uint64_t mintxg, uint64_t maxtxg,
994     uint64_t *usedp, uint64_t *compp, uint64_t *uncompp)
995 {
996 	struct space_range_arg sra = { 0 };
997 	int err;
998 
999 	ASSERT(bpobj_is_open(bpo));
1000 
1001 	/*
1002 	 * As an optimization, if they want the whole txg range, just
1003 	 * get bpo_bytes rather than iterating over the bps.
1004 	 */
1005 	if (mintxg < TXG_INITIAL && maxtxg == UINT64_MAX && bpo->bpo_havecomp)
1006 		return (bpobj_space(bpo, usedp, compp, uncompp));
1007 
1008 	sra.spa = dmu_objset_spa(bpo->bpo_os);
1009 	sra.mintxg = mintxg;
1010 	sra.maxtxg = maxtxg;
1011 
1012 	err = bpobj_iterate_nofree(bpo, space_range_cb, &sra, NULL);
1013 	*usedp = sra.used;
1014 	*compp = sra.comp;
1015 	*uncompp = sra.uncomp;
1016 	return (err);
1017 }
1018 
1019 /*
1020  * A bpobj_itor_t to append blkptrs to a bplist. Note that while blkptrs in a
1021  * bpobj are designated as free or allocated that information is not preserved
1022  * in bplists.
1023  */
1024 int
bplist_append_cb(void * arg,const blkptr_t * bp,boolean_t bp_freed,dmu_tx_t * tx)1025 bplist_append_cb(void *arg, const blkptr_t *bp, boolean_t bp_freed,
1026     dmu_tx_t *tx)
1027 {
1028 	(void) bp_freed, (void) tx;
1029 	bplist_t *bpl = arg;
1030 	bplist_append(bpl, bp);
1031 	return (0);
1032 }
1033