xref: /freebsd/sys/contrib/openzfs/module/zfs/bpobj.c (revision 22649d4dba730d46244fd2dff4fd174903c8379f)
1 // SPDX-License-Identifier: CDDL-1.0
2 /*
3  * This file and its contents are supplied under the terms of the
4  * Common Development and Distribution License ("CDDL"), version 1.0.
5  * You may only use this file in accordance with the terms of version
6  * 1.0 of the CDDL.
7  *
8  * A full copy of the text of the CDDL should have accompanied this
9  * source.  A copy of the CDDL is also available via the Internet at
10  * https://opensource.org/license/CDDL-1.0.
11  */
12 /*
13  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
14  * Copyright (c) 2011, 2018 by Delphix. All rights reserved.
15  * Copyright (c) 2017 Datto Inc.
16  */
17 
18 #include <sys/bpobj.h>
19 #include <sys/zfs_context.h>
20 #include <sys/zfs_refcount.h>
21 #include <sys/dsl_pool.h>
22 #include <sys/zfeature.h>
23 #include <sys/zap.h>
24 
25 /*
26  * Return an empty bpobj, preferably the empty dummy one (dp_empty_bpobj).
27  */
28 uint64_t
bpobj_alloc_empty(objset_t * os,int blocksize,dmu_tx_t * tx)29 bpobj_alloc_empty(objset_t *os, int blocksize, dmu_tx_t *tx)
30 {
31 	spa_t *spa = dmu_objset_spa(os);
32 	dsl_pool_t *dp = dmu_objset_pool(os);
33 
34 	if (spa_feature_is_enabled(spa, SPA_FEATURE_EMPTY_BPOBJ)) {
35 		if (!spa_feature_is_active(spa, SPA_FEATURE_EMPTY_BPOBJ)) {
36 			ASSERT0(dp->dp_empty_bpobj);
37 			dp->dp_empty_bpobj =
38 			    bpobj_alloc(os, SPA_OLD_MAXBLOCKSIZE, tx);
39 			VERIFY(zap_add(os,
40 			    DMU_POOL_DIRECTORY_OBJECT,
41 			    DMU_POOL_EMPTY_BPOBJ, sizeof (uint64_t), 1,
42 			    &dp->dp_empty_bpobj, tx) == 0);
43 		}
44 		spa_feature_incr(spa, SPA_FEATURE_EMPTY_BPOBJ, tx);
45 		ASSERT(dp->dp_empty_bpobj != 0);
46 		return (dp->dp_empty_bpobj);
47 	} else {
48 		return (bpobj_alloc(os, blocksize, tx));
49 	}
50 }
51 
52 void
bpobj_decr_empty(objset_t * os,dmu_tx_t * tx)53 bpobj_decr_empty(objset_t *os, dmu_tx_t *tx)
54 {
55 	dsl_pool_t *dp = dmu_objset_pool(os);
56 
57 	spa_feature_decr(dmu_objset_spa(os), SPA_FEATURE_EMPTY_BPOBJ, tx);
58 	if (!spa_feature_is_active(dmu_objset_spa(os),
59 	    SPA_FEATURE_EMPTY_BPOBJ)) {
60 		VERIFY3U(0, ==, zap_remove(dp->dp_meta_objset,
61 		    DMU_POOL_DIRECTORY_OBJECT,
62 		    DMU_POOL_EMPTY_BPOBJ, tx));
63 		VERIFY3U(0, ==, dmu_object_free(os, dp->dp_empty_bpobj, tx));
64 		dp->dp_empty_bpobj = 0;
65 	}
66 }
67 
68 uint64_t
bpobj_alloc(objset_t * os,int blocksize,dmu_tx_t * tx)69 bpobj_alloc(objset_t *os, int blocksize, dmu_tx_t *tx)
70 {
71 	int size;
72 
73 	if (spa_version(dmu_objset_spa(os)) < SPA_VERSION_BPOBJ_ACCOUNT)
74 		size = BPOBJ_SIZE_V0;
75 	else if (spa_version(dmu_objset_spa(os)) < SPA_VERSION_DEADLISTS)
76 		size = BPOBJ_SIZE_V1;
77 	else if (!spa_feature_is_active(dmu_objset_spa(os),
78 	    SPA_FEATURE_LIVELIST))
79 		size = BPOBJ_SIZE_V2;
80 	else
81 		size = sizeof (bpobj_phys_t);
82 
83 	return (dmu_object_alloc(os, DMU_OT_BPOBJ, blocksize,
84 	    DMU_OT_BPOBJ_HDR, size, tx));
85 }
86 
87 void
bpobj_free(objset_t * os,uint64_t obj,dmu_tx_t * tx)88 bpobj_free(objset_t *os, uint64_t obj, dmu_tx_t *tx)
89 {
90 	int64_t i;
91 	bpobj_t bpo;
92 	dmu_object_info_t doi;
93 	int epb;
94 	dmu_buf_t *dbuf = NULL;
95 
96 	ASSERT(obj != dmu_objset_pool(os)->dp_empty_bpobj);
97 	VERIFY3U(0, ==, bpobj_open(&bpo, os, obj));
98 
99 	mutex_enter(&bpo.bpo_lock);
100 
101 	if (!bpo.bpo_havesubobj || bpo.bpo_phys->bpo_subobjs == 0)
102 		goto out;
103 
104 	VERIFY3U(0, ==, dmu_object_info(os, bpo.bpo_phys->bpo_subobjs, &doi));
105 	epb = doi.doi_data_block_size / sizeof (uint64_t);
106 
107 	for (i = bpo.bpo_phys->bpo_num_subobjs - 1; i >= 0; i--) {
108 		uint64_t *objarray;
109 		uint64_t offset, blkoff;
110 
111 		offset = i * sizeof (uint64_t);
112 		blkoff = P2PHASE(i, epb);
113 
114 		if (dbuf == NULL || dbuf->db_offset > offset) {
115 			if (dbuf)
116 				dmu_buf_rele(dbuf, FTAG);
117 			VERIFY3U(0, ==, dmu_buf_hold(os,
118 			    bpo.bpo_phys->bpo_subobjs, offset, FTAG, &dbuf, 0));
119 		}
120 
121 		ASSERT3U(offset, >=, dbuf->db_offset);
122 		ASSERT3U(offset, <, dbuf->db_offset + dbuf->db_size);
123 
124 		objarray = dbuf->db_data;
125 		bpobj_free(os, objarray[blkoff], tx);
126 	}
127 	if (dbuf) {
128 		dmu_buf_rele(dbuf, FTAG);
129 		dbuf = NULL;
130 	}
131 	VERIFY3U(0, ==, dmu_object_free(os, bpo.bpo_phys->bpo_subobjs, tx));
132 
133 out:
134 	mutex_exit(&bpo.bpo_lock);
135 	bpobj_close(&bpo);
136 
137 	VERIFY3U(0, ==, dmu_object_free(os, obj, tx));
138 }
139 
140 int
bpobj_open(bpobj_t * bpo,objset_t * os,uint64_t object)141 bpobj_open(bpobj_t *bpo, objset_t *os, uint64_t object)
142 {
143 	dmu_object_info_t doi;
144 	int err;
145 
146 	err = dmu_object_info(os, object, &doi);
147 	if (err)
148 		return (err);
149 
150 	memset(bpo, 0, sizeof (*bpo));
151 	mutex_init(&bpo->bpo_lock, NULL, MUTEX_DEFAULT, NULL);
152 
153 	ASSERT0P(bpo->bpo_dbuf);
154 	ASSERT0P(bpo->bpo_phys);
155 	ASSERT(object != 0);
156 	ASSERT3U(doi.doi_type, ==, DMU_OT_BPOBJ);
157 	ASSERT3U(doi.doi_bonus_type, ==, DMU_OT_BPOBJ_HDR);
158 
159 	err = dmu_bonus_hold(os, object, bpo, &bpo->bpo_dbuf);
160 	if (err)
161 		return (err);
162 
163 	bpo->bpo_os = os;
164 	bpo->bpo_object = object;
165 	bpo->bpo_epb = doi.doi_data_block_size >> SPA_BLKPTRSHIFT;
166 	bpo->bpo_havecomp = (doi.doi_bonus_size > BPOBJ_SIZE_V0);
167 	bpo->bpo_havesubobj = (doi.doi_bonus_size > BPOBJ_SIZE_V1);
168 	bpo->bpo_havefreed = (doi.doi_bonus_size > BPOBJ_SIZE_V2);
169 	bpo->bpo_phys = bpo->bpo_dbuf->db_data;
170 	return (0);
171 }
172 
173 boolean_t
bpobj_is_open(const bpobj_t * bpo)174 bpobj_is_open(const bpobj_t *bpo)
175 {
176 	return (bpo->bpo_object != 0);
177 }
178 
179 void
bpobj_close(bpobj_t * bpo)180 bpobj_close(bpobj_t *bpo)
181 {
182 	/* Lame workaround for closing a bpobj that was never opened. */
183 	if (bpo->bpo_object == 0)
184 		return;
185 
186 	dmu_buf_rele(bpo->bpo_dbuf, bpo);
187 	if (bpo->bpo_cached_dbuf != NULL)
188 		dmu_buf_rele(bpo->bpo_cached_dbuf, bpo);
189 	bpo->bpo_dbuf = NULL;
190 	bpo->bpo_phys = NULL;
191 	bpo->bpo_cached_dbuf = NULL;
192 	bpo->bpo_object = 0;
193 
194 	mutex_destroy(&bpo->bpo_lock);
195 }
196 
197 static boolean_t
bpobj_is_empty_impl(bpobj_t * bpo)198 bpobj_is_empty_impl(bpobj_t *bpo)
199 {
200 	ASSERT(MUTEX_HELD(&bpo->bpo_lock));
201 	return (bpo->bpo_phys->bpo_num_blkptrs == 0 &&
202 	    (!bpo->bpo_havesubobj || bpo->bpo_phys->bpo_num_subobjs == 0));
203 }
204 
205 boolean_t
bpobj_is_empty(bpobj_t * bpo)206 bpobj_is_empty(bpobj_t *bpo)
207 {
208 	mutex_enter(&bpo->bpo_lock);
209 	boolean_t is_empty = bpobj_is_empty_impl(bpo);
210 	mutex_exit(&bpo->bpo_lock);
211 	return (is_empty);
212 }
213 
214 /*
215  * A recursive iteration of the bpobjs would be nice here but we run the risk
216  * of overflowing function stack space.  Instead, find each subobj and add it
217  * to the head of our list so it can be scanned for subjobjs.  Like a
218  * recursive implementation, the "deepest" subobjs will be freed first.
219  * When a subobj is found to have no additional subojs, free it.
220  */
221 typedef struct bpobj_info {
222 	bpobj_t *bpi_bpo;
223 	/*
224 	 * This object is a subobj of bpi_parent,
225 	 * at bpi_index in its subobj array.
226 	 */
227 	struct bpobj_info *bpi_parent;
228 	uint64_t bpi_index;
229 	/* How many of our subobj's are left to process. */
230 	uint64_t bpi_unprocessed_subobjs;
231 	/* True after having visited this bpo's directly referenced BPs. */
232 	boolean_t bpi_visited;
233 	list_node_t bpi_node;
234 } bpobj_info_t;
235 
236 static bpobj_info_t *
bpi_alloc(bpobj_t * bpo,bpobj_info_t * parent,uint64_t index)237 bpi_alloc(bpobj_t *bpo, bpobj_info_t *parent, uint64_t index)
238 {
239 	bpobj_info_t *bpi = kmem_zalloc(sizeof (bpobj_info_t), KM_SLEEP);
240 	bpi->bpi_bpo = bpo;
241 	bpi->bpi_parent = parent;
242 	bpi->bpi_index = index;
243 	if (bpo->bpo_havesubobj && bpo->bpo_phys->bpo_subobjs != 0) {
244 		bpi->bpi_unprocessed_subobjs = bpo->bpo_phys->bpo_num_subobjs;
245 	}
246 	return (bpi);
247 }
248 
249 /*
250  * Update bpobj and all of its parents with new space accounting.
251  */
252 static void
propagate_space_reduction(bpobj_info_t * bpi,int64_t freed,int64_t comp_freed,int64_t uncomp_freed,dmu_tx_t * tx)253 propagate_space_reduction(bpobj_info_t *bpi, int64_t freed,
254     int64_t comp_freed, int64_t uncomp_freed, dmu_tx_t *tx)
255 {
256 
257 	for (; bpi != NULL; bpi = bpi->bpi_parent) {
258 		bpobj_t *p = bpi->bpi_bpo;
259 		ASSERT(dmu_buf_is_dirty(p->bpo_dbuf, tx));
260 		p->bpo_phys->bpo_bytes -= freed;
261 		ASSERT3S(p->bpo_phys->bpo_bytes, >=, 0);
262 		if (p->bpo_havecomp) {
263 			p->bpo_phys->bpo_comp -= comp_freed;
264 			p->bpo_phys->bpo_uncomp -= uncomp_freed;
265 		}
266 	}
267 }
268 
269 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)270 bpobj_iterate_blkptrs(bpobj_info_t *bpi, bpobj_itor_t func, void *arg,
271     int64_t start, dmu_tx_t *tx, boolean_t free)
272 {
273 	int err = 0;
274 	int64_t freed = 0, comp_freed = 0, uncomp_freed = 0;
275 	dmu_buf_t *dbuf = NULL;
276 	bpobj_t *bpo = bpi->bpi_bpo;
277 
278 	int64_t i = bpo->bpo_phys->bpo_num_blkptrs - 1;
279 	uint64_t pe = P2ALIGN_TYPED(i, bpo->bpo_epb, uint64_t) *
280 	    sizeof (blkptr_t);
281 	uint64_t ps = start * sizeof (blkptr_t);
282 	uint64_t pb = MAX((pe > dmu_prefetch_max) ? pe - dmu_prefetch_max : 0,
283 	    ps);
284 	if (pe > pb) {
285 		dmu_prefetch(bpo->bpo_os, bpo->bpo_object, 0, pb, pe - pb,
286 		    ZIO_PRIORITY_ASYNC_READ);
287 	}
288 	for (; i >= start; i--) {
289 		uint64_t offset = i * sizeof (blkptr_t);
290 		uint64_t blkoff = P2PHASE(i, bpo->bpo_epb);
291 
292 		if (dbuf == NULL || dbuf->db_offset > offset) {
293 			if (dbuf)
294 				dmu_buf_rele(dbuf, FTAG);
295 			err = dmu_buf_hold(bpo->bpo_os, bpo->bpo_object,
296 			    offset, FTAG, &dbuf, DMU_READ_NO_PREFETCH);
297 			if (err)
298 				break;
299 			pe = pb;
300 			pb = MAX((dbuf->db_offset > dmu_prefetch_max) ?
301 			    dbuf->db_offset - dmu_prefetch_max : 0, ps);
302 			if (pe > pb) {
303 				dmu_prefetch(bpo->bpo_os, bpo->bpo_object, 0,
304 				    pb, pe - pb, ZIO_PRIORITY_ASYNC_READ);
305 			}
306 		}
307 
308 		ASSERT3U(offset, >=, dbuf->db_offset);
309 		ASSERT3U(offset, <, dbuf->db_offset + dbuf->db_size);
310 
311 		blkptr_t *bparray = dbuf->db_data;
312 		blkptr_t *bp = &bparray[blkoff];
313 
314 		boolean_t bp_freed = BP_GET_FREE(bp);
315 		err = func(arg, bp, bp_freed, tx);
316 		if (err)
317 			break;
318 
319 		if (free) {
320 			int sign = bp_freed ? -1 : +1;
321 			spa_t *spa = dmu_objset_spa(bpo->bpo_os);
322 			freed += sign * bp_get_dsize_sync(spa, bp);
323 			comp_freed += sign * BP_GET_PSIZE(bp);
324 			uncomp_freed += sign * BP_GET_UCSIZE(bp);
325 			ASSERT(dmu_buf_is_dirty(bpo->bpo_dbuf, tx));
326 			bpo->bpo_phys->bpo_num_blkptrs--;
327 			ASSERT3S(bpo->bpo_phys->bpo_num_blkptrs, >=, 0);
328 			if (bp_freed) {
329 				ASSERT(bpo->bpo_havefreed);
330 				bpo->bpo_phys->bpo_num_freed--;
331 				ASSERT3S(bpo->bpo_phys->bpo_num_freed, >=, 0);
332 			}
333 		}
334 	}
335 	if (free) {
336 		propagate_space_reduction(bpi, freed, comp_freed,
337 		    uncomp_freed, tx);
338 		VERIFY0(dmu_free_range(bpo->bpo_os,
339 		    bpo->bpo_object,
340 		    bpo->bpo_phys->bpo_num_blkptrs * sizeof (blkptr_t),
341 		    DMU_OBJECT_END, tx));
342 	}
343 	if (dbuf) {
344 		dmu_buf_rele(dbuf, FTAG);
345 		dbuf = NULL;
346 	}
347 	return (err);
348 }
349 
350 /*
351  * Given an initial bpo, start by freeing the BPs that are directly referenced
352  * by that bpo. If the bpo has subobjs, read in its last subobj and push the
353  * subobj to our stack. By popping items off our stack, eventually we will
354  * encounter a bpo that has no subobjs.  We can free its bpobj_info_t, and if
355  * requested also free the now-empty bpo from disk and decrement
356  * its parent's subobj count. We continue popping each subobj from our stack,
357  * visiting its last subobj until they too have no more subobjs, and so on.
358  */
359 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)360 bpobj_iterate_impl(bpobj_t *initial_bpo, bpobj_itor_t func, void *arg,
361     dmu_tx_t *tx, boolean_t free, uint64_t *bpobj_size)
362 {
363 	list_t stack;
364 	bpobj_info_t *bpi;
365 	int err = 0;
366 
367 	/*
368 	 * Create a "stack" for us to work with without worrying about
369 	 * stack overflows. Initialize it with the initial_bpo.
370 	 */
371 	list_create(&stack, sizeof (bpobj_info_t),
372 	    offsetof(bpobj_info_t, bpi_node));
373 	mutex_enter(&initial_bpo->bpo_lock);
374 
375 	if (bpobj_size != NULL)
376 		*bpobj_size = initial_bpo->bpo_phys->bpo_num_blkptrs;
377 
378 	list_insert_head(&stack, bpi_alloc(initial_bpo, NULL, 0));
379 
380 	while ((bpi = list_head(&stack)) != NULL) {
381 		bpobj_t *bpo = bpi->bpi_bpo;
382 
383 		ASSERT3P(bpo, !=, NULL);
384 		ASSERT(MUTEX_HELD(&bpo->bpo_lock));
385 		ASSERT(bpobj_is_open(bpo));
386 
387 		if (free)
388 			dmu_buf_will_dirty(bpo->bpo_dbuf, tx);
389 
390 		if (bpi->bpi_visited == B_FALSE) {
391 			err = bpobj_iterate_blkptrs(bpi, func, arg, 0, tx,
392 			    free);
393 			bpi->bpi_visited = B_TRUE;
394 			if (err != 0)
395 				break;
396 		}
397 		/*
398 		 * We've finished with this bpo's directly-referenced BP's and
399 		 * it has no more unprocessed subobjs. We can free its
400 		 * bpobj_info_t (unless it is the topmost, initial_bpo).
401 		 * If we are freeing from disk, we can also do that.
402 		 */
403 		if (bpi->bpi_unprocessed_subobjs == 0) {
404 			/*
405 			 * If there are no entries, there should
406 			 * be no bytes.
407 			 */
408 			if (bpobj_is_empty_impl(bpo)) {
409 				ASSERT0(bpo->bpo_phys->bpo_bytes);
410 				ASSERT0(bpo->bpo_phys->bpo_comp);
411 				ASSERT0(bpo->bpo_phys->bpo_uncomp);
412 			}
413 
414 			/* The initial_bpo has no parent and is not closed. */
415 			if (bpi->bpi_parent != NULL) {
416 				if (free) {
417 					bpobj_t *p = bpi->bpi_parent->bpi_bpo;
418 
419 					ASSERT0(bpo->bpo_phys->bpo_num_blkptrs);
420 					ASSERT3U(p->bpo_phys->bpo_num_subobjs,
421 					    >, 0);
422 					ASSERT3U(bpi->bpi_index, ==,
423 					    p->bpo_phys->bpo_num_subobjs - 1);
424 					ASSERT(dmu_buf_is_dirty(bpo->bpo_dbuf,
425 					    tx));
426 
427 					p->bpo_phys->bpo_num_subobjs--;
428 
429 					VERIFY0(dmu_free_range(p->bpo_os,
430 					    p->bpo_phys->bpo_subobjs,
431 					    bpi->bpi_index * sizeof (uint64_t),
432 					    sizeof (uint64_t), tx));
433 
434 					/* eliminate the empty subobj list */
435 					if (bpo->bpo_havesubobj &&
436 					    bpo->bpo_phys->bpo_subobjs != 0) {
437 						ASSERT0(bpo->bpo_phys->
438 						    bpo_num_subobjs);
439 						err = dmu_object_free(
440 						    bpo->bpo_os,
441 						    bpo->bpo_phys->bpo_subobjs,
442 						    tx);
443 						if (err)
444 							break;
445 						bpo->bpo_phys->bpo_subobjs = 0;
446 					}
447 					err = dmu_object_free(p->bpo_os,
448 					    bpo->bpo_object, tx);
449 					if (err)
450 						break;
451 				}
452 
453 				mutex_exit(&bpo->bpo_lock);
454 				bpobj_close(bpo);
455 				kmem_free(bpo, sizeof (bpobj_t));
456 			} else {
457 				mutex_exit(&bpo->bpo_lock);
458 			}
459 
460 			/*
461 			 * Finished processing this bpo. Unlock, and free
462 			 * our "stack" info.
463 			 */
464 			list_remove_head(&stack);
465 			kmem_free(bpi, sizeof (bpobj_info_t));
466 		} else {
467 			/*
468 			 * We have unprocessed subobjs. Process the next one.
469 			 */
470 			ASSERT(bpo->bpo_havecomp);
471 			ASSERT0P(bpobj_size);
472 
473 			/* Add the last subobj to stack. */
474 			int64_t i = bpi->bpi_unprocessed_subobjs - 1;
475 			uint64_t offset = i * sizeof (uint64_t);
476 
477 			uint64_t subobj;
478 			err = dmu_read(bpo->bpo_os, bpo->bpo_phys->bpo_subobjs,
479 			    offset, sizeof (uint64_t), &subobj,
480 			    DMU_READ_NO_PREFETCH);
481 			if (err)
482 				break;
483 
484 			bpobj_t *subbpo = kmem_alloc(sizeof (bpobj_t),
485 			    KM_SLEEP);
486 			err = bpobj_open(subbpo, bpo->bpo_os, subobj);
487 			if (err) {
488 				kmem_free(subbpo, sizeof (bpobj_t));
489 				break;
490 			}
491 
492 			if (subbpo->bpo_havesubobj &&
493 			    subbpo->bpo_phys->bpo_subobjs != 0) {
494 				dmu_prefetch(subbpo->bpo_os,
495 				    subbpo->bpo_phys->bpo_subobjs, 0, 0, 0,
496 				    ZIO_PRIORITY_ASYNC_READ);
497 			}
498 
499 			list_insert_head(&stack, bpi_alloc(subbpo, bpi, i));
500 			mutex_enter(&subbpo->bpo_lock);
501 			bpi->bpi_unprocessed_subobjs--;
502 		}
503 	}
504 	/*
505 	 * Cleanup anything left on the "stack" after we left the loop.
506 	 * Every bpo on the stack is locked so we must remember to undo
507 	 * that now (in LIFO order).
508 	 */
509 	while ((bpi = list_remove_head(&stack)) != NULL) {
510 		bpobj_t *bpo = bpi->bpi_bpo;
511 		ASSERT(err != 0);
512 		ASSERT3P(bpo, !=, NULL);
513 
514 		mutex_exit(&bpo->bpo_lock);
515 
516 		/* do not free the initial_bpo */
517 		if (bpi->bpi_parent != NULL) {
518 			bpobj_close(bpi->bpi_bpo);
519 			kmem_free(bpi->bpi_bpo, sizeof (bpobj_t));
520 		}
521 		kmem_free(bpi, sizeof (bpobj_info_t));
522 	}
523 
524 	list_destroy(&stack);
525 
526 	return (err);
527 }
528 
529 /*
530  * Iterate and remove the entries.  If func returns nonzero, iteration
531  * will stop and that entry will not be removed.
532  */
533 int
bpobj_iterate(bpobj_t * bpo,bpobj_itor_t func,void * arg,dmu_tx_t * tx)534 bpobj_iterate(bpobj_t *bpo, bpobj_itor_t func, void *arg, dmu_tx_t *tx)
535 {
536 	return (bpobj_iterate_impl(bpo, func, arg, tx, B_TRUE, NULL));
537 }
538 
539 /*
540  * Iterate the entries.  If func returns nonzero, iteration will stop.
541  *
542  * If there are no subobjs:
543  *
544  * *bpobj_size can be used to return the number of block pointers in the
545  * bpobj.  Note that this may be different from the number of block pointers
546  * that are iterated over, if iteration is terminated early (e.g. by the func
547  * returning nonzero).
548  *
549  * If there are concurrent (or subsequent) modifications to the bpobj then the
550  * returned *bpobj_size can be passed as "start" to
551  * livelist_bpobj_iterate_from_nofree() to iterate the newly added entries.
552  */
553 int
bpobj_iterate_nofree(bpobj_t * bpo,bpobj_itor_t func,void * arg,uint64_t * bpobj_size)554 bpobj_iterate_nofree(bpobj_t *bpo, bpobj_itor_t func, void *arg,
555     uint64_t *bpobj_size)
556 {
557 	return (bpobj_iterate_impl(bpo, func, arg, NULL, B_FALSE, bpobj_size));
558 }
559 
560 /*
561  * Iterate over the blkptrs in the bpobj beginning at index start. If func
562  * returns nonzero, iteration will stop. This is a livelist specific function
563  * since it assumes that there are no subobjs present.
564  */
565 int
livelist_bpobj_iterate_from_nofree(bpobj_t * bpo,bpobj_itor_t func,void * arg,int64_t start)566 livelist_bpobj_iterate_from_nofree(bpobj_t *bpo, bpobj_itor_t func, void *arg,
567     int64_t start)
568 {
569 	if (bpo->bpo_havesubobj)
570 		VERIFY0(bpo->bpo_phys->bpo_subobjs);
571 	bpobj_info_t *bpi = bpi_alloc(bpo, NULL, 0);
572 	int err = bpobj_iterate_blkptrs(bpi, func, arg, start, NULL, B_FALSE);
573 	kmem_free(bpi, sizeof (bpobj_info_t));
574 	return (err);
575 }
576 
577 /*
578  * Logically add subobj's contents to the parent bpobj.
579  *
580  * In the most general case, this is accomplished in constant time by adding
581  * a reference to subobj.  This case is used when enqueuing a large subobj:
582  * +--------------+                        +--------------+
583  * | bpobj        |----------------------->| subobj list  |
584  * +----+----+----+----+----+              +-----+-----+--+--+
585  * | bp | bp | bp | bp | bp |              | obj | obj | obj |
586  * +----+----+----+----+----+              +-----+-----+-----+
587  *
588  * +--------------+                        +--------------+
589  * | sub-bpobj    |----------------------> | subsubobj    |
590  * +----+----+----+----+---------+----+    +-----+-----+--+--------+-----+
591  * | bp | bp | bp | bp |   ...   | bp |    | obj | obj |    ...    | obj |
592  * +----+----+----+----+---------+----+    +-----+-----+-----------+-----+
593  *
594  * Result: sub-bpobj added to parent's subobj list.
595  * +--------------+                        +--------------+
596  * | bpobj        |----------------------->| subobj list  |
597  * +----+----+----+----+----+              +-----+-----+--+--+-----+
598  * | bp | bp | bp | bp | bp |              | obj | obj | obj | OBJ |
599  * +----+----+----+----+----+              +-----+-----+-----+--|--+
600  *                                                              |
601  *       /-----------------------------------------------------/
602  *       v
603  * +--------------+                        +--------------+
604  * | sub-bpobj    |----------------------> | subsubobj    |
605  * +----+----+----+----+---------+----+    +-----+-----+--+--------+-----+
606  * | bp | bp | bp | bp |   ...   | bp |    | obj | obj |    ...    | obj |
607  * +----+----+----+----+---------+----+    +-----+-----+-----------+-----+
608  *
609  *
610  * In a common case, the subobj is small: its bp's and its list of subobj's
611  * are each stored in a single block.  In this case we copy the subobj's
612  * contents to the parent:
613  * +--------------+                        +--------------+
614  * | bpobj        |----------------------->| subobj list  |
615  * +----+----+----+----+----+              +-----+-----+--+--+
616  * | bp | bp | bp | bp | bp |              | obj | obj | obj |
617  * +----+----+----+----+----+              +-----+-----+-----+
618  *                          ^                                ^
619  * +--------------+         |              +--------------+  |
620  * | sub-bpobj    |---------^------------> | subsubobj    |  ^
621  * +----+----+----+         |              +-----+-----+--+  |
622  * | BP | BP |-->-->-->-->-/               | OBJ | OBJ |-->-/
623  * +----+----+                             +-----+-----+
624  *
625  * Result: subobj destroyed, contents copied to parent:
626  * +--------------+                        +--------------+
627  * | bpobj        |----------------------->| subobj list  |
628  * +----+----+----+----+----+----+----+    +-----+-----+--+--+-----+-----+
629  * | bp | bp | bp | bp | bp | BP | BP |    | obj | obj | obj | OBJ | OBJ |
630  * +----+----+----+----+----+----+----+    +-----+-----+-----+-----+-----+
631  *
632  *
633  * If the subobj has many BP's but few subobj's, we can copy the sub-subobj's
634  * but retain the sub-bpobj:
635  * +--------------+                        +--------------+
636  * | bpobj        |----------------------->| subobj list  |
637  * +----+----+----+----+----+              +-----+-----+--+--+
638  * | bp | bp | bp | bp | bp |              | obj | obj | obj |
639  * +----+----+----+----+----+              +-----+-----+-----+
640  *                                                           ^
641  * +--------------+                        +--------------+  |
642  * | sub-bpobj    |----------------------> | subsubobj    |  ^
643  * +----+----+----+----+---------+----+    +-----+-----+--+  |
644  * | bp | bp | bp | bp |   ...   | bp |    | OBJ | OBJ |-->-/
645  * +----+----+----+----+---------+----+    +-----+-----+
646  *
647  * Result: sub-sub-bpobjs and subobj added to parent's subobj list.
648  * +--------------+                     +--------------+
649  * | bpobj        |-------------------->| subobj list  |
650  * +----+----+----+----+----+           +-----+-----+--+--+-----+-----+------+
651  * | bp | bp | bp | bp | bp |           | obj | obj | obj | OBJ | OBJ | OBJ* |
652  * +----+----+----+----+----+           +-----+-----+-----+-----+-----+--|---+
653  *                                                                       |
654  *       /--------------------------------------------------------------/
655  *       v
656  * +--------------+
657  * | sub-bpobj    |
658  * +----+----+----+----+---------+----+
659  * | bp | bp | bp | bp |   ...   | bp |
660  * +----+----+----+----+---------+----+
661  */
662 void
bpobj_enqueue_subobj(bpobj_t * bpo,uint64_t subobj,dmu_tx_t * tx)663 bpobj_enqueue_subobj(bpobj_t *bpo, uint64_t subobj, dmu_tx_t *tx)
664 {
665 	bpobj_t subbpo;
666 	uint64_t used, comp, uncomp, subsubobjs;
667 	boolean_t copy_subsub = B_TRUE;
668 	boolean_t copy_bps = B_TRUE;
669 
670 	ASSERT(bpobj_is_open(bpo));
671 	ASSERT(subobj != 0);
672 	ASSERT(bpo->bpo_havesubobj);
673 	ASSERT(bpo->bpo_havecomp);
674 	ASSERT(bpo->bpo_object != dmu_objset_pool(bpo->bpo_os)->dp_empty_bpobj);
675 
676 	if (subobj == dmu_objset_pool(bpo->bpo_os)->dp_empty_bpobj) {
677 		bpobj_decr_empty(bpo->bpo_os, tx);
678 		return;
679 	}
680 
681 	VERIFY3U(0, ==, bpobj_open(&subbpo, bpo->bpo_os, subobj));
682 	if (bpobj_is_empty(&subbpo)) {
683 		/* No point in having an empty subobj. */
684 		bpobj_close(&subbpo);
685 		bpobj_free(bpo->bpo_os, subobj, tx);
686 		return;
687 	}
688 	VERIFY3U(0, ==, bpobj_space(&subbpo, &used, &comp, &uncomp));
689 
690 	mutex_enter(&bpo->bpo_lock);
691 	dmu_buf_will_dirty(bpo->bpo_dbuf, tx);
692 
693 	dmu_object_info_t doi;
694 
695 	if (bpo->bpo_phys->bpo_subobjs != 0) {
696 		ASSERT0(dmu_object_info(bpo->bpo_os, bpo->bpo_phys->bpo_subobjs,
697 		    &doi));
698 		ASSERT3U(doi.doi_type, ==, DMU_OT_BPOBJ_SUBOBJ);
699 	}
700 
701 	/*
702 	 * If subobj has only one block of subobjs, then move subobj's
703 	 * subobjs to bpo's subobj list directly.  This reduces recursion in
704 	 * bpobj_iterate due to nested subobjs.
705 	 */
706 	subsubobjs = subbpo.bpo_phys->bpo_subobjs;
707 	if (subsubobjs != 0) {
708 		VERIFY0(dmu_object_info(bpo->bpo_os, subsubobjs, &doi));
709 		if (doi.doi_max_offset > doi.doi_data_block_size) {
710 			copy_subsub = B_FALSE;
711 		}
712 	}
713 
714 	/*
715 	 * If, in addition to having only one block of subobj's, subobj has
716 	 * only one block of bp's, then move subobj's bp's to bpo's bp list
717 	 * directly. This reduces recursion in bpobj_iterate due to nested
718 	 * subobjs.
719 	 */
720 	VERIFY3U(0, ==, dmu_object_info(bpo->bpo_os, subobj, &doi));
721 	if (doi.doi_max_offset > doi.doi_data_block_size || !copy_subsub) {
722 		copy_bps = B_FALSE;
723 	}
724 
725 	if (copy_subsub && subsubobjs != 0) {
726 		dmu_buf_t *subdb;
727 		uint64_t numsubsub = subbpo.bpo_phys->bpo_num_subobjs;
728 
729 		VERIFY0(dmu_buf_hold(bpo->bpo_os, subsubobjs,
730 		    0, FTAG, &subdb, 0));
731 		/*
732 		 * Make sure that we are not asking dmu_write()
733 		 * to write more data than we have in our buffer.
734 		 */
735 		VERIFY3U(subdb->db_size, >=,
736 		    numsubsub * sizeof (subobj));
737 		if (bpo->bpo_phys->bpo_subobjs == 0) {
738 			bpo->bpo_phys->bpo_subobjs =
739 			    dmu_object_alloc(bpo->bpo_os,
740 			    DMU_OT_BPOBJ_SUBOBJ, SPA_OLD_MAXBLOCKSIZE,
741 			    DMU_OT_NONE, 0, tx);
742 		}
743 		dmu_write(bpo->bpo_os, bpo->bpo_phys->bpo_subobjs,
744 		    bpo->bpo_phys->bpo_num_subobjs * sizeof (subobj),
745 		    numsubsub * sizeof (subobj), subdb->db_data, tx,
746 		    DMU_READ_NO_PREFETCH);
747 		dmu_buf_rele(subdb, FTAG);
748 		bpo->bpo_phys->bpo_num_subobjs += numsubsub;
749 
750 		dmu_buf_will_dirty(subbpo.bpo_dbuf, tx);
751 		subbpo.bpo_phys->bpo_subobjs = 0;
752 		VERIFY0(dmu_object_free(bpo->bpo_os, subsubobjs, tx));
753 	}
754 
755 	if (copy_bps) {
756 		dmu_buf_t *bps;
757 		uint64_t numbps = subbpo.bpo_phys->bpo_num_blkptrs;
758 
759 		ASSERT(copy_subsub);
760 		VERIFY0(dmu_buf_hold(bpo->bpo_os, subobj,
761 		    0, FTAG, &bps, 0));
762 
763 		/*
764 		 * Make sure that we are not asking dmu_write()
765 		 * to write more data than we have in our buffer.
766 		 */
767 		VERIFY3U(bps->db_size, >=, numbps * sizeof (blkptr_t));
768 		dmu_write(bpo->bpo_os, bpo->bpo_object,
769 		    bpo->bpo_phys->bpo_num_blkptrs * sizeof (blkptr_t),
770 		    numbps * sizeof (blkptr_t),
771 		    bps->db_data, tx, DMU_READ_NO_PREFETCH);
772 		dmu_buf_rele(bps, FTAG);
773 		bpo->bpo_phys->bpo_num_blkptrs += numbps;
774 
775 		bpobj_close(&subbpo);
776 		VERIFY0(dmu_object_free(bpo->bpo_os, subobj, tx));
777 	} else {
778 		bpobj_close(&subbpo);
779 		if (bpo->bpo_phys->bpo_subobjs == 0) {
780 			bpo->bpo_phys->bpo_subobjs =
781 			    dmu_object_alloc(bpo->bpo_os,
782 			    DMU_OT_BPOBJ_SUBOBJ, SPA_OLD_MAXBLOCKSIZE,
783 			    DMU_OT_NONE, 0, tx);
784 		}
785 
786 		dmu_write(bpo->bpo_os, bpo->bpo_phys->bpo_subobjs,
787 		    bpo->bpo_phys->bpo_num_subobjs * sizeof (subobj),
788 		    sizeof (subobj), &subobj, tx, DMU_READ_NO_PREFETCH);
789 		bpo->bpo_phys->bpo_num_subobjs++;
790 	}
791 
792 	bpo->bpo_phys->bpo_bytes += used;
793 	bpo->bpo_phys->bpo_comp += comp;
794 	bpo->bpo_phys->bpo_uncomp += uncomp;
795 	mutex_exit(&bpo->bpo_lock);
796 
797 }
798 
799 /*
800  * Prefetch metadata required for bpobj_enqueue_subobj().
801  */
802 void
bpobj_prefetch_subobj(bpobj_t * bpo,uint64_t subobj)803 bpobj_prefetch_subobj(bpobj_t *bpo, uint64_t subobj)
804 {
805 	dmu_object_info_t doi;
806 	bpobj_t subbpo;
807 	uint64_t subsubobjs;
808 	boolean_t copy_subsub = B_TRUE;
809 	boolean_t copy_bps = B_TRUE;
810 
811 	ASSERT(bpobj_is_open(bpo));
812 	ASSERT(subobj != 0);
813 
814 	if (subobj == dmu_objset_pool(bpo->bpo_os)->dp_empty_bpobj)
815 		return;
816 
817 	if (bpobj_open(&subbpo, bpo->bpo_os, subobj) != 0)
818 		return;
819 	if (bpobj_is_empty(&subbpo)) {
820 		bpobj_close(&subbpo);
821 		return;
822 	}
823 	subsubobjs = subbpo.bpo_phys->bpo_subobjs;
824 	bpobj_close(&subbpo);
825 
826 	if (subsubobjs != 0) {
827 		if (dmu_object_info(bpo->bpo_os, subsubobjs, &doi) != 0)
828 			return;
829 		if (doi.doi_max_offset > doi.doi_data_block_size)
830 			copy_subsub = B_FALSE;
831 	}
832 
833 	if (dmu_object_info(bpo->bpo_os, subobj, &doi) != 0)
834 		return;
835 	if (doi.doi_max_offset > doi.doi_data_block_size || !copy_subsub)
836 		copy_bps = B_FALSE;
837 
838 	if (copy_subsub && subsubobjs != 0) {
839 		if (bpo->bpo_phys->bpo_subobjs) {
840 			dmu_prefetch(bpo->bpo_os, bpo->bpo_phys->bpo_subobjs, 0,
841 			    bpo->bpo_phys->bpo_num_subobjs * sizeof (subobj), 1,
842 			    ZIO_PRIORITY_ASYNC_READ);
843 		}
844 		dmu_prefetch(bpo->bpo_os, subsubobjs, 0, 0, 1,
845 		    ZIO_PRIORITY_ASYNC_READ);
846 	}
847 
848 	if (copy_bps) {
849 		dmu_prefetch(bpo->bpo_os, bpo->bpo_object, 0,
850 		    bpo->bpo_phys->bpo_num_blkptrs * sizeof (blkptr_t), 1,
851 		    ZIO_PRIORITY_ASYNC_READ);
852 		dmu_prefetch(bpo->bpo_os, subobj, 0, 0, 1,
853 		    ZIO_PRIORITY_ASYNC_READ);
854 	} else if (bpo->bpo_phys->bpo_subobjs) {
855 		dmu_prefetch(bpo->bpo_os, bpo->bpo_phys->bpo_subobjs, 0,
856 		    bpo->bpo_phys->bpo_num_subobjs * sizeof (subobj), 1,
857 		    ZIO_PRIORITY_ASYNC_READ);
858 	}
859 }
860 
861 void
bpobj_enqueue(bpobj_t * bpo,const blkptr_t * bp,boolean_t bp_freed,dmu_tx_t * tx)862 bpobj_enqueue(bpobj_t *bpo, const blkptr_t *bp, boolean_t bp_freed,
863     dmu_tx_t *tx)
864 {
865 	blkptr_t stored_bp = *bp;
866 	uint64_t offset;
867 	int blkoff;
868 	blkptr_t *bparray;
869 
870 	ASSERT(bpobj_is_open(bpo));
871 	ASSERT(!BP_IS_HOLE(bp));
872 	ASSERT(bpo->bpo_object != dmu_objset_pool(bpo->bpo_os)->dp_empty_bpobj);
873 
874 	if (BP_IS_EMBEDDED(bp)) {
875 		/*
876 		 * The bpobj will compress better without the payload.
877 		 *
878 		 * Note that we store EMBEDDED bp's because they have an
879 		 * uncompressed size, which must be accounted for.  An
880 		 * alternative would be to add their size to bpo_uncomp
881 		 * without storing the bp, but that would create additional
882 		 * complications: bpo_uncomp would be inconsistent with the
883 		 * set of BP's stored, and bpobj_iterate() wouldn't visit
884 		 * all the space accounted for in the bpobj.
885 		 */
886 		memset(&stored_bp, 0, sizeof (stored_bp));
887 		stored_bp.blk_prop = bp->blk_prop;
888 		BP_SET_LOGICAL_BIRTH(&stored_bp, BP_GET_LOGICAL_BIRTH(bp));
889 	} else if (!BP_GET_DEDUP(bp)) {
890 		/* The bpobj will compress better without the checksum */
891 		memset(&stored_bp.blk_cksum, 0, sizeof (stored_bp.blk_cksum));
892 	}
893 
894 	stored_bp.blk_fill = 0;
895 	BP_SET_FREE(&stored_bp, bp_freed);
896 
897 	mutex_enter(&bpo->bpo_lock);
898 
899 	offset = bpo->bpo_phys->bpo_num_blkptrs * sizeof (stored_bp);
900 	blkoff = P2PHASE(bpo->bpo_phys->bpo_num_blkptrs, bpo->bpo_epb);
901 
902 	if (bpo->bpo_cached_dbuf == NULL ||
903 	    offset < bpo->bpo_cached_dbuf->db_offset ||
904 	    offset >= bpo->bpo_cached_dbuf->db_offset +
905 	    bpo->bpo_cached_dbuf->db_size) {
906 		if (bpo->bpo_cached_dbuf)
907 			dmu_buf_rele(bpo->bpo_cached_dbuf, bpo);
908 		VERIFY3U(0, ==, dmu_buf_hold(bpo->bpo_os, bpo->bpo_object,
909 		    offset, bpo, &bpo->bpo_cached_dbuf, 0));
910 		ASSERT3P(bpo->bpo_cached_dbuf, !=, NULL);
911 	}
912 
913 	dmu_buf_will_dirty(bpo->bpo_cached_dbuf, tx);
914 	bparray = bpo->bpo_cached_dbuf->db_data;
915 	bparray[blkoff] = stored_bp;
916 
917 	dmu_buf_will_dirty(bpo->bpo_dbuf, tx);
918 	bpo->bpo_phys->bpo_num_blkptrs++;
919 	int sign = bp_freed ? -1 : +1;
920 	bpo->bpo_phys->bpo_bytes += sign *
921 	    bp_get_dsize_sync(dmu_objset_spa(bpo->bpo_os), bp);
922 	if (bpo->bpo_havecomp) {
923 		bpo->bpo_phys->bpo_comp += sign * BP_GET_PSIZE(bp);
924 		bpo->bpo_phys->bpo_uncomp += sign * BP_GET_UCSIZE(bp);
925 	}
926 	if (bp_freed) {
927 		ASSERT(bpo->bpo_havefreed);
928 		bpo->bpo_phys->bpo_num_freed++;
929 	}
930 	mutex_exit(&bpo->bpo_lock);
931 }
932 
933 struct space_range_arg {
934 	spa_t *spa;
935 	uint64_t mintxg;
936 	uint64_t maxtxg;
937 	uint64_t used;
938 	uint64_t comp;
939 	uint64_t uncomp;
940 };
941 
942 static int
space_range_cb(void * arg,const blkptr_t * bp,boolean_t bp_freed,dmu_tx_t * tx)943 space_range_cb(void *arg, const blkptr_t *bp, boolean_t bp_freed, dmu_tx_t *tx)
944 {
945 	(void) bp_freed, (void) tx;
946 	struct space_range_arg *sra = arg;
947 
948 	if (BP_GET_BIRTH(bp) > sra->mintxg &&
949 	    BP_GET_BIRTH(bp) <= sra->maxtxg) {
950 		if (dsl_pool_sync_context(spa_get_dsl(sra->spa)))
951 			sra->used += bp_get_dsize_sync(sra->spa, bp);
952 		else
953 			sra->used += bp_get_dsize(sra->spa, bp);
954 		sra->comp += BP_GET_PSIZE(bp);
955 		sra->uncomp += BP_GET_UCSIZE(bp);
956 	}
957 	return (0);
958 }
959 
960 int
bpobj_space(bpobj_t * bpo,uint64_t * usedp,uint64_t * compp,uint64_t * uncompp)961 bpobj_space(bpobj_t *bpo, uint64_t *usedp, uint64_t *compp, uint64_t *uncompp)
962 {
963 	ASSERT(bpobj_is_open(bpo));
964 	mutex_enter(&bpo->bpo_lock);
965 
966 	*usedp = bpo->bpo_phys->bpo_bytes;
967 	if (bpo->bpo_havecomp) {
968 		*compp = bpo->bpo_phys->bpo_comp;
969 		*uncompp = bpo->bpo_phys->bpo_uncomp;
970 		mutex_exit(&bpo->bpo_lock);
971 		return (0);
972 	} else {
973 		mutex_exit(&bpo->bpo_lock);
974 		return (bpobj_space_range(bpo, 0, UINT64_MAX,
975 		    usedp, compp, uncompp));
976 	}
977 }
978 
979 /*
980  * Return the amount of space in the bpobj which is:
981  * mintxg < logical birth <= maxtxg
982  */
983 int
bpobj_space_range(bpobj_t * bpo,uint64_t mintxg,uint64_t maxtxg,uint64_t * usedp,uint64_t * compp,uint64_t * uncompp)984 bpobj_space_range(bpobj_t *bpo, uint64_t mintxg, uint64_t maxtxg,
985     uint64_t *usedp, uint64_t *compp, uint64_t *uncompp)
986 {
987 	struct space_range_arg sra = { 0 };
988 	int err;
989 
990 	ASSERT(bpobj_is_open(bpo));
991 
992 	/*
993 	 * As an optimization, if they want the whole txg range, just
994 	 * get bpo_bytes rather than iterating over the bps.
995 	 */
996 	if (mintxg < TXG_INITIAL && maxtxg == UINT64_MAX && bpo->bpo_havecomp)
997 		return (bpobj_space(bpo, usedp, compp, uncompp));
998 
999 	sra.spa = dmu_objset_spa(bpo->bpo_os);
1000 	sra.mintxg = mintxg;
1001 	sra.maxtxg = maxtxg;
1002 
1003 	err = bpobj_iterate_nofree(bpo, space_range_cb, &sra, NULL);
1004 	*usedp = sra.used;
1005 	*compp = sra.comp;
1006 	*uncompp = sra.uncomp;
1007 	return (err);
1008 }
1009 
1010 /*
1011  * A bpobj_itor_t to append blkptrs to a bplist. Note that while blkptrs in a
1012  * bpobj are designated as free or allocated that information is not preserved
1013  * in bplists.
1014  */
1015 int
bplist_append_cb(void * arg,const blkptr_t * bp,boolean_t bp_freed,dmu_tx_t * tx)1016 bplist_append_cb(void *arg, const blkptr_t *bp, boolean_t bp_freed,
1017     dmu_tx_t *tx)
1018 {
1019 	(void) bp_freed, (void) tx;
1020 	bplist_t *bpl = arg;
1021 	bplist_append(bpl, bp);
1022 	return (0);
1023 }
1024