xref: /titanic_52/usr/src/uts/common/fs/zfs/dnode_sync.c (revision 5dbfd19ad5fcc2b779f40f80fa05c1bd28fd0b4e)
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) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
24  * Copyright (c) 2012 by Delphix. All rights reserved.
25  */
26 
27 #include <sys/zfs_context.h>
28 #include <sys/dbuf.h>
29 #include <sys/dnode.h>
30 #include <sys/dmu.h>
31 #include <sys/dmu_tx.h>
32 #include <sys/dmu_objset.h>
33 #include <sys/dsl_dataset.h>
34 #include <sys/spa.h>
35 
36 static void
37 dnode_increase_indirection(dnode_t *dn, dmu_tx_t *tx)
38 {
39 	dmu_buf_impl_t *db;
40 	int txgoff = tx->tx_txg & TXG_MASK;
41 	int nblkptr = dn->dn_phys->dn_nblkptr;
42 	int old_toplvl = dn->dn_phys->dn_nlevels - 1;
43 	int new_level = dn->dn_next_nlevels[txgoff];
44 	int i;
45 
46 	rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
47 
48 	/* this dnode can't be paged out because it's dirty */
49 	ASSERT(dn->dn_phys->dn_type != DMU_OT_NONE);
50 	ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock));
51 	ASSERT(new_level > 1 && dn->dn_phys->dn_nlevels > 0);
52 
53 	db = dbuf_hold_level(dn, dn->dn_phys->dn_nlevels, 0, FTAG);
54 	ASSERT(db != NULL);
55 
56 	dn->dn_phys->dn_nlevels = new_level;
57 	dprintf("os=%p obj=%llu, increase to %d\n", dn->dn_objset,
58 	    dn->dn_object, dn->dn_phys->dn_nlevels);
59 
60 	/* check for existing blkptrs in the dnode */
61 	for (i = 0; i < nblkptr; i++)
62 		if (!BP_IS_HOLE(&dn->dn_phys->dn_blkptr[i]))
63 			break;
64 	if (i != nblkptr) {
65 		/* transfer dnode's block pointers to new indirect block */
66 		(void) dbuf_read(db, NULL, DB_RF_MUST_SUCCEED|DB_RF_HAVESTRUCT);
67 		ASSERT(db->db.db_data);
68 		ASSERT(arc_released(db->db_buf));
69 		ASSERT3U(sizeof (blkptr_t) * nblkptr, <=, db->db.db_size);
70 		bcopy(dn->dn_phys->dn_blkptr, db->db.db_data,
71 		    sizeof (blkptr_t) * nblkptr);
72 		arc_buf_freeze(db->db_buf);
73 	}
74 
75 	/* set dbuf's parent pointers to new indirect buf */
76 	for (i = 0; i < nblkptr; i++) {
77 		dmu_buf_impl_t *child = dbuf_find(dn, old_toplvl, i);
78 
79 		if (child == NULL)
80 			continue;
81 #ifdef	DEBUG
82 		DB_DNODE_ENTER(child);
83 		ASSERT3P(DB_DNODE(child), ==, dn);
84 		DB_DNODE_EXIT(child);
85 #endif	/* DEBUG */
86 		if (child->db_parent && child->db_parent != dn->dn_dbuf) {
87 			ASSERT(child->db_parent->db_level == db->db_level);
88 			ASSERT(child->db_blkptr !=
89 			    &dn->dn_phys->dn_blkptr[child->db_blkid]);
90 			mutex_exit(&child->db_mtx);
91 			continue;
92 		}
93 		ASSERT(child->db_parent == NULL ||
94 		    child->db_parent == dn->dn_dbuf);
95 
96 		child->db_parent = db;
97 		dbuf_add_ref(db, child);
98 		if (db->db.db_data)
99 			child->db_blkptr = (blkptr_t *)db->db.db_data + i;
100 		else
101 			child->db_blkptr = NULL;
102 		dprintf_dbuf_bp(child, child->db_blkptr,
103 		    "changed db_blkptr to new indirect %s", "");
104 
105 		mutex_exit(&child->db_mtx);
106 	}
107 
108 	bzero(dn->dn_phys->dn_blkptr, sizeof (blkptr_t) * nblkptr);
109 
110 	dbuf_rele(db, FTAG);
111 
112 	rw_exit(&dn->dn_struct_rwlock);
113 }
114 
115 static int
116 free_blocks(dnode_t *dn, blkptr_t *bp, int num, dmu_tx_t *tx)
117 {
118 	dsl_dataset_t *ds = dn->dn_objset->os_dsl_dataset;
119 	uint64_t bytesfreed = 0;
120 	int i, blocks_freed = 0;
121 
122 	dprintf("ds=%p obj=%llx num=%d\n", ds, dn->dn_object, num);
123 
124 	for (i = 0; i < num; i++, bp++) {
125 		if (BP_IS_HOLE(bp))
126 			continue;
127 
128 		bytesfreed += dsl_dataset_block_kill(ds, bp, tx, B_FALSE);
129 		ASSERT3U(bytesfreed, <=, DN_USED_BYTES(dn->dn_phys));
130 		bzero(bp, sizeof (blkptr_t));
131 		blocks_freed += 1;
132 	}
133 	dnode_diduse_space(dn, -bytesfreed);
134 	return (blocks_freed);
135 }
136 
137 #ifdef ZFS_DEBUG
138 static void
139 free_verify(dmu_buf_impl_t *db, uint64_t start, uint64_t end, dmu_tx_t *tx)
140 {
141 	int off, num;
142 	int i, err, epbs;
143 	uint64_t txg = tx->tx_txg;
144 	dnode_t *dn;
145 
146 	DB_DNODE_ENTER(db);
147 	dn = DB_DNODE(db);
148 	epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT;
149 	off = start - (db->db_blkid * 1<<epbs);
150 	num = end - start + 1;
151 
152 	ASSERT3U(off, >=, 0);
153 	ASSERT3U(num, >=, 0);
154 	ASSERT3U(db->db_level, >, 0);
155 	ASSERT3U(db->db.db_size, ==, 1 << dn->dn_phys->dn_indblkshift);
156 	ASSERT3U(off+num, <=, db->db.db_size >> SPA_BLKPTRSHIFT);
157 	ASSERT(db->db_blkptr != NULL);
158 
159 	for (i = off; i < off+num; i++) {
160 		uint64_t *buf;
161 		dmu_buf_impl_t *child;
162 		dbuf_dirty_record_t *dr;
163 		int j;
164 
165 		ASSERT(db->db_level == 1);
166 
167 		rw_enter(&dn->dn_struct_rwlock, RW_READER);
168 		err = dbuf_hold_impl(dn, db->db_level-1,
169 		    (db->db_blkid << epbs) + i, TRUE, FTAG, &child);
170 		rw_exit(&dn->dn_struct_rwlock);
171 		if (err == ENOENT)
172 			continue;
173 		ASSERT(err == 0);
174 		ASSERT(child->db_level == 0);
175 		dr = child->db_last_dirty;
176 		while (dr && dr->dr_txg > txg)
177 			dr = dr->dr_next;
178 		ASSERT(dr == NULL || dr->dr_txg == txg);
179 
180 		/* data_old better be zeroed */
181 		if (dr) {
182 			buf = dr->dt.dl.dr_data->b_data;
183 			for (j = 0; j < child->db.db_size >> 3; j++) {
184 				if (buf[j] != 0) {
185 					panic("freed data not zero: "
186 					    "child=%p i=%d off=%d num=%d\n",
187 					    (void *)child, i, off, num);
188 				}
189 			}
190 		}
191 
192 		/*
193 		 * db_data better be zeroed unless it's dirty in a
194 		 * future txg.
195 		 */
196 		mutex_enter(&child->db_mtx);
197 		buf = child->db.db_data;
198 		if (buf != NULL && child->db_state != DB_FILL &&
199 		    child->db_last_dirty == NULL) {
200 			for (j = 0; j < child->db.db_size >> 3; j++) {
201 				if (buf[j] != 0) {
202 					panic("freed data not zero: "
203 					    "child=%p i=%d off=%d num=%d\n",
204 					    (void *)child, i, off, num);
205 				}
206 			}
207 		}
208 		mutex_exit(&child->db_mtx);
209 
210 		dbuf_rele(child, FTAG);
211 	}
212 	DB_DNODE_EXIT(db);
213 }
214 #endif
215 
216 #define	ALL -1
217 
218 static int
219 free_children(dmu_buf_impl_t *db, uint64_t blkid, uint64_t nblks, int trunc,
220     dmu_tx_t *tx)
221 {
222 	dnode_t *dn;
223 	blkptr_t *bp;
224 	dmu_buf_impl_t *subdb;
225 	uint64_t start, end, dbstart, dbend, i;
226 	int epbs, shift, err;
227 	int all = TRUE;
228 	int blocks_freed = 0;
229 
230 	/*
231 	 * There is a small possibility that this block will not be cached:
232 	 *   1 - if level > 1 and there are no children with level <= 1
233 	 *   2 - if we didn't get a dirty hold (because this block had just
234 	 *	 finished being written -- and so had no holds), and then this
235 	 *	 block got evicted before we got here.
236 	 */
237 	if (db->db_state != DB_CACHED)
238 		(void) dbuf_read(db, NULL, DB_RF_MUST_SUCCEED);
239 
240 	dbuf_release_bp(db);
241 	bp = (blkptr_t *)db->db.db_data;
242 
243 	DB_DNODE_ENTER(db);
244 	dn = DB_DNODE(db);
245 	epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT;
246 	shift = (db->db_level - 1) * epbs;
247 	dbstart = db->db_blkid << epbs;
248 	start = blkid >> shift;
249 	if (dbstart < start) {
250 		bp += start - dbstart;
251 		all = FALSE;
252 	} else {
253 		start = dbstart;
254 	}
255 	dbend = ((db->db_blkid + 1) << epbs) - 1;
256 	end = (blkid + nblks - 1) >> shift;
257 	if (dbend <= end)
258 		end = dbend;
259 	else if (all)
260 		all = trunc;
261 	ASSERT3U(start, <=, end);
262 
263 	if (db->db_level == 1) {
264 		FREE_VERIFY(db, start, end, tx);
265 		blocks_freed = free_blocks(dn, bp, end-start+1, tx);
266 		arc_buf_freeze(db->db_buf);
267 		ASSERT(all || blocks_freed == 0 || db->db_last_dirty);
268 		DB_DNODE_EXIT(db);
269 		return (all ? ALL : blocks_freed);
270 	}
271 
272 	for (i = start; i <= end; i++, bp++) {
273 		if (BP_IS_HOLE(bp))
274 			continue;
275 		rw_enter(&dn->dn_struct_rwlock, RW_READER);
276 		err = dbuf_hold_impl(dn, db->db_level-1, i, TRUE, FTAG, &subdb);
277 		ASSERT0(err);
278 		rw_exit(&dn->dn_struct_rwlock);
279 
280 		if (free_children(subdb, blkid, nblks, trunc, tx) == ALL) {
281 			ASSERT3P(subdb->db_blkptr, ==, bp);
282 			blocks_freed += free_blocks(dn, bp, 1, tx);
283 		} else {
284 			all = FALSE;
285 		}
286 		dbuf_rele(subdb, FTAG);
287 	}
288 	DB_DNODE_EXIT(db);
289 	arc_buf_freeze(db->db_buf);
290 #ifdef ZFS_DEBUG
291 	bp -= (end-start)+1;
292 	for (i = start; i <= end; i++, bp++) {
293 		if (i == start && blkid != 0)
294 			continue;
295 		else if (i == end && !trunc)
296 			continue;
297 		ASSERT0(bp->blk_birth);
298 	}
299 #endif
300 	ASSERT(all || blocks_freed == 0 || db->db_last_dirty);
301 	return (all ? ALL : blocks_freed);
302 }
303 
304 /*
305  * free_range: Traverse the indicated range of the provided file
306  * and "free" all the blocks contained there.
307  */
308 static void
309 dnode_sync_free_range(dnode_t *dn, uint64_t blkid, uint64_t nblks, dmu_tx_t *tx)
310 {
311 	blkptr_t *bp = dn->dn_phys->dn_blkptr;
312 	dmu_buf_impl_t *db;
313 	int trunc, start, end, shift, i, err;
314 	int dnlevel = dn->dn_phys->dn_nlevels;
315 
316 	if (blkid > dn->dn_phys->dn_maxblkid)
317 		return;
318 
319 	ASSERT(dn->dn_phys->dn_maxblkid < UINT64_MAX);
320 	trunc = blkid + nblks > dn->dn_phys->dn_maxblkid;
321 	if (trunc)
322 		nblks = dn->dn_phys->dn_maxblkid - blkid + 1;
323 
324 	/* There are no indirect blocks in the object */
325 	if (dnlevel == 1) {
326 		if (blkid >= dn->dn_phys->dn_nblkptr) {
327 			/* this range was never made persistent */
328 			return;
329 		}
330 		ASSERT3U(blkid + nblks, <=, dn->dn_phys->dn_nblkptr);
331 		(void) free_blocks(dn, bp + blkid, nblks, tx);
332 		if (trunc) {
333 			uint64_t off = (dn->dn_phys->dn_maxblkid + 1) *
334 			    (dn->dn_phys->dn_datablkszsec << SPA_MINBLOCKSHIFT);
335 			dn->dn_phys->dn_maxblkid = (blkid ? blkid - 1 : 0);
336 			ASSERT(off < dn->dn_phys->dn_maxblkid ||
337 			    dn->dn_phys->dn_maxblkid == 0 ||
338 			    dnode_next_offset(dn, 0, &off, 1, 1, 0) != 0);
339 		}
340 		return;
341 	}
342 
343 	shift = (dnlevel - 1) * (dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT);
344 	start = blkid >> shift;
345 	ASSERT(start < dn->dn_phys->dn_nblkptr);
346 	end = (blkid + nblks - 1) >> shift;
347 	bp += start;
348 	for (i = start; i <= end; i++, bp++) {
349 		if (BP_IS_HOLE(bp))
350 			continue;
351 		rw_enter(&dn->dn_struct_rwlock, RW_READER);
352 		err = dbuf_hold_impl(dn, dnlevel-1, i, TRUE, FTAG, &db);
353 		ASSERT0(err);
354 		rw_exit(&dn->dn_struct_rwlock);
355 
356 		if (free_children(db, blkid, nblks, trunc, tx) == ALL) {
357 			ASSERT3P(db->db_blkptr, ==, bp);
358 			(void) free_blocks(dn, bp, 1, tx);
359 		}
360 		dbuf_rele(db, FTAG);
361 	}
362 	if (trunc) {
363 		uint64_t off = (dn->dn_phys->dn_maxblkid + 1) *
364 		    (dn->dn_phys->dn_datablkszsec << SPA_MINBLOCKSHIFT);
365 		dn->dn_phys->dn_maxblkid = (blkid ? blkid - 1 : 0);
366 		ASSERT(off < dn->dn_phys->dn_maxblkid ||
367 		    dn->dn_phys->dn_maxblkid == 0 ||
368 		    dnode_next_offset(dn, 0, &off, 1, 1, 0) != 0);
369 	}
370 }
371 
372 /*
373  * Try to kick all the dnodes dbufs out of the cache...
374  */
375 void
376 dnode_evict_dbufs(dnode_t *dn)
377 {
378 	int progress;
379 	int pass = 0;
380 
381 	do {
382 		dmu_buf_impl_t *db, marker;
383 		int evicting = FALSE;
384 
385 		progress = FALSE;
386 		mutex_enter(&dn->dn_dbufs_mtx);
387 		list_insert_tail(&dn->dn_dbufs, &marker);
388 		db = list_head(&dn->dn_dbufs);
389 		for (; db != &marker; db = list_head(&dn->dn_dbufs)) {
390 			list_remove(&dn->dn_dbufs, db);
391 			list_insert_tail(&dn->dn_dbufs, db);
392 #ifdef	DEBUG
393 			DB_DNODE_ENTER(db);
394 			ASSERT3P(DB_DNODE(db), ==, dn);
395 			DB_DNODE_EXIT(db);
396 #endif	/* DEBUG */
397 
398 			mutex_enter(&db->db_mtx);
399 			if (db->db_state == DB_EVICTING) {
400 				progress = TRUE;
401 				evicting = TRUE;
402 				mutex_exit(&db->db_mtx);
403 			} else if (refcount_is_zero(&db->db_holds)) {
404 				progress = TRUE;
405 				dbuf_clear(db); /* exits db_mtx for us */
406 			} else {
407 				mutex_exit(&db->db_mtx);
408 			}
409 
410 		}
411 		list_remove(&dn->dn_dbufs, &marker);
412 		/*
413 		 * NB: we need to drop dn_dbufs_mtx between passes so
414 		 * that any DB_EVICTING dbufs can make progress.
415 		 * Ideally, we would have some cv we could wait on, but
416 		 * since we don't, just wait a bit to give the other
417 		 * thread a chance to run.
418 		 */
419 		mutex_exit(&dn->dn_dbufs_mtx);
420 		if (evicting)
421 			delay(1);
422 		pass++;
423 		ASSERT(pass < 100); /* sanity check */
424 	} while (progress);
425 
426 	rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
427 	if (dn->dn_bonus && refcount_is_zero(&dn->dn_bonus->db_holds)) {
428 		mutex_enter(&dn->dn_bonus->db_mtx);
429 		dbuf_evict(dn->dn_bonus);
430 		dn->dn_bonus = NULL;
431 	}
432 	rw_exit(&dn->dn_struct_rwlock);
433 }
434 
435 static void
436 dnode_undirty_dbufs(list_t *list)
437 {
438 	dbuf_dirty_record_t *dr;
439 
440 	while (dr = list_head(list)) {
441 		dmu_buf_impl_t *db = dr->dr_dbuf;
442 		uint64_t txg = dr->dr_txg;
443 
444 		if (db->db_level != 0)
445 			dnode_undirty_dbufs(&dr->dt.di.dr_children);
446 
447 		mutex_enter(&db->db_mtx);
448 		/* XXX - use dbuf_undirty()? */
449 		list_remove(list, dr);
450 		ASSERT(db->db_last_dirty == dr);
451 		db->db_last_dirty = NULL;
452 		db->db_dirtycnt -= 1;
453 		if (db->db_level == 0) {
454 			ASSERT(db->db_blkid == DMU_BONUS_BLKID ||
455 			    dr->dt.dl.dr_data == db->db_buf);
456 			dbuf_unoverride(dr);
457 		}
458 		kmem_free(dr, sizeof (dbuf_dirty_record_t));
459 		dbuf_rele_and_unlock(db, (void *)(uintptr_t)txg);
460 	}
461 }
462 
463 static void
464 dnode_sync_free(dnode_t *dn, dmu_tx_t *tx)
465 {
466 	int txgoff = tx->tx_txg & TXG_MASK;
467 
468 	ASSERT(dmu_tx_is_syncing(tx));
469 
470 	/*
471 	 * Our contents should have been freed in dnode_sync() by the
472 	 * free range record inserted by the caller of dnode_free().
473 	 */
474 	ASSERT0(DN_USED_BYTES(dn->dn_phys));
475 	ASSERT(BP_IS_HOLE(dn->dn_phys->dn_blkptr));
476 
477 	dnode_undirty_dbufs(&dn->dn_dirty_records[txgoff]);
478 	dnode_evict_dbufs(dn);
479 	ASSERT3P(list_head(&dn->dn_dbufs), ==, NULL);
480 	ASSERT3P(dn->dn_bonus, ==, NULL);
481 
482 	/*
483 	 * XXX - It would be nice to assert this, but we may still
484 	 * have residual holds from async evictions from the arc...
485 	 *
486 	 * zfs_obj_to_path() also depends on this being
487 	 * commented out.
488 	 *
489 	 * ASSERT3U(refcount_count(&dn->dn_holds), ==, 1);
490 	 */
491 
492 	/* Undirty next bits */
493 	dn->dn_next_nlevels[txgoff] = 0;
494 	dn->dn_next_indblkshift[txgoff] = 0;
495 	dn->dn_next_blksz[txgoff] = 0;
496 
497 	/* ASSERT(blkptrs are zero); */
498 	ASSERT(dn->dn_phys->dn_type != DMU_OT_NONE);
499 	ASSERT(dn->dn_type != DMU_OT_NONE);
500 
501 	ASSERT(dn->dn_free_txg > 0);
502 	if (dn->dn_allocated_txg != dn->dn_free_txg)
503 		dbuf_will_dirty(dn->dn_dbuf, tx);
504 	bzero(dn->dn_phys, sizeof (dnode_phys_t));
505 
506 	mutex_enter(&dn->dn_mtx);
507 	dn->dn_type = DMU_OT_NONE;
508 	dn->dn_maxblkid = 0;
509 	dn->dn_allocated_txg = 0;
510 	dn->dn_free_txg = 0;
511 	dn->dn_have_spill = B_FALSE;
512 	mutex_exit(&dn->dn_mtx);
513 
514 	ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT);
515 
516 	dnode_rele(dn, (void *)(uintptr_t)tx->tx_txg);
517 	/*
518 	 * Now that we've released our hold, the dnode may
519 	 * be evicted, so we musn't access it.
520 	 */
521 }
522 
523 /*
524  * Write out the dnode's dirty buffers.
525  */
526 void
527 dnode_sync(dnode_t *dn, dmu_tx_t *tx)
528 {
529 	free_range_t *rp;
530 	dnode_phys_t *dnp = dn->dn_phys;
531 	int txgoff = tx->tx_txg & TXG_MASK;
532 	list_t *list = &dn->dn_dirty_records[txgoff];
533 	static const dnode_phys_t zerodn = { 0 };
534 	boolean_t kill_spill = B_FALSE;
535 
536 	ASSERT(dmu_tx_is_syncing(tx));
537 	ASSERT(dnp->dn_type != DMU_OT_NONE || dn->dn_allocated_txg);
538 	ASSERT(dnp->dn_type != DMU_OT_NONE ||
539 	    bcmp(dnp, &zerodn, DNODE_SIZE) == 0);
540 	DNODE_VERIFY(dn);
541 
542 	ASSERT(dn->dn_dbuf == NULL || arc_released(dn->dn_dbuf->db_buf));
543 
544 	if (dmu_objset_userused_enabled(dn->dn_objset) &&
545 	    !DMU_OBJECT_IS_SPECIAL(dn->dn_object)) {
546 		mutex_enter(&dn->dn_mtx);
547 		dn->dn_oldused = DN_USED_BYTES(dn->dn_phys);
548 		dn->dn_oldflags = dn->dn_phys->dn_flags;
549 		dn->dn_phys->dn_flags |= DNODE_FLAG_USERUSED_ACCOUNTED;
550 		mutex_exit(&dn->dn_mtx);
551 		dmu_objset_userquota_get_ids(dn, B_FALSE, tx);
552 	} else {
553 		/* Once we account for it, we should always account for it. */
554 		ASSERT(!(dn->dn_phys->dn_flags &
555 		    DNODE_FLAG_USERUSED_ACCOUNTED));
556 	}
557 
558 	mutex_enter(&dn->dn_mtx);
559 	if (dn->dn_allocated_txg == tx->tx_txg) {
560 		/* The dnode is newly allocated or reallocated */
561 		if (dnp->dn_type == DMU_OT_NONE) {
562 			/* this is a first alloc, not a realloc */
563 			dnp->dn_nlevels = 1;
564 			dnp->dn_nblkptr = dn->dn_nblkptr;
565 		}
566 
567 		dnp->dn_type = dn->dn_type;
568 		dnp->dn_bonustype = dn->dn_bonustype;
569 		dnp->dn_bonuslen = dn->dn_bonuslen;
570 	}
571 
572 	ASSERT(dnp->dn_nlevels > 1 ||
573 	    BP_IS_HOLE(&dnp->dn_blkptr[0]) ||
574 	    BP_GET_LSIZE(&dnp->dn_blkptr[0]) ==
575 	    dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT);
576 
577 	if (dn->dn_next_blksz[txgoff]) {
578 		ASSERT(P2PHASE(dn->dn_next_blksz[txgoff],
579 		    SPA_MINBLOCKSIZE) == 0);
580 		ASSERT(BP_IS_HOLE(&dnp->dn_blkptr[0]) ||
581 		    dn->dn_maxblkid == 0 || list_head(list) != NULL ||
582 		    avl_last(&dn->dn_ranges[txgoff]) ||
583 		    dn->dn_next_blksz[txgoff] >> SPA_MINBLOCKSHIFT ==
584 		    dnp->dn_datablkszsec);
585 		dnp->dn_datablkszsec =
586 		    dn->dn_next_blksz[txgoff] >> SPA_MINBLOCKSHIFT;
587 		dn->dn_next_blksz[txgoff] = 0;
588 	}
589 
590 	if (dn->dn_next_bonuslen[txgoff]) {
591 		if (dn->dn_next_bonuslen[txgoff] == DN_ZERO_BONUSLEN)
592 			dnp->dn_bonuslen = 0;
593 		else
594 			dnp->dn_bonuslen = dn->dn_next_bonuslen[txgoff];
595 		ASSERT(dnp->dn_bonuslen <= DN_MAX_BONUSLEN);
596 		dn->dn_next_bonuslen[txgoff] = 0;
597 	}
598 
599 	if (dn->dn_next_bonustype[txgoff]) {
600 		ASSERT(DMU_OT_IS_VALID(dn->dn_next_bonustype[txgoff]));
601 		dnp->dn_bonustype = dn->dn_next_bonustype[txgoff];
602 		dn->dn_next_bonustype[txgoff] = 0;
603 	}
604 
605 	/*
606 	 * We will either remove a spill block when a file is being removed
607 	 * or we have been asked to remove it.
608 	 */
609 	if (dn->dn_rm_spillblk[txgoff] ||
610 	    ((dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) &&
611 	    dn->dn_free_txg > 0 && dn->dn_free_txg <= tx->tx_txg)) {
612 		if ((dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR))
613 			kill_spill = B_TRUE;
614 		dn->dn_rm_spillblk[txgoff] = 0;
615 	}
616 
617 	if (dn->dn_next_indblkshift[txgoff]) {
618 		ASSERT(dnp->dn_nlevels == 1);
619 		dnp->dn_indblkshift = dn->dn_next_indblkshift[txgoff];
620 		dn->dn_next_indblkshift[txgoff] = 0;
621 	}
622 
623 	/*
624 	 * Just take the live (open-context) values for checksum and compress.
625 	 * Strictly speaking it's a future leak, but nothing bad happens if we
626 	 * start using the new checksum or compress algorithm a little early.
627 	 */
628 	dnp->dn_checksum = dn->dn_checksum;
629 	dnp->dn_compress = dn->dn_compress;
630 
631 	mutex_exit(&dn->dn_mtx);
632 
633 	if (kill_spill) {
634 		(void) free_blocks(dn, &dn->dn_phys->dn_spill, 1, tx);
635 		mutex_enter(&dn->dn_mtx);
636 		dnp->dn_flags &= ~DNODE_FLAG_SPILL_BLKPTR;
637 		mutex_exit(&dn->dn_mtx);
638 	}
639 
640 	/* process all the "freed" ranges in the file */
641 	while (rp = avl_last(&dn->dn_ranges[txgoff])) {
642 		dnode_sync_free_range(dn, rp->fr_blkid, rp->fr_nblks, tx);
643 		/* grab the mutex so we don't race with dnode_block_freed() */
644 		mutex_enter(&dn->dn_mtx);
645 		avl_remove(&dn->dn_ranges[txgoff], rp);
646 		mutex_exit(&dn->dn_mtx);
647 		kmem_free(rp, sizeof (free_range_t));
648 	}
649 
650 	if (dn->dn_free_txg > 0 && dn->dn_free_txg <= tx->tx_txg) {
651 		dnode_sync_free(dn, tx);
652 		return;
653 	}
654 
655 	if (dn->dn_next_nblkptr[txgoff]) {
656 		/* this should only happen on a realloc */
657 		ASSERT(dn->dn_allocated_txg == tx->tx_txg);
658 		if (dn->dn_next_nblkptr[txgoff] > dnp->dn_nblkptr) {
659 			/* zero the new blkptrs we are gaining */
660 			bzero(dnp->dn_blkptr + dnp->dn_nblkptr,
661 			    sizeof (blkptr_t) *
662 			    (dn->dn_next_nblkptr[txgoff] - dnp->dn_nblkptr));
663 #ifdef ZFS_DEBUG
664 		} else {
665 			int i;
666 			ASSERT(dn->dn_next_nblkptr[txgoff] < dnp->dn_nblkptr);
667 			/* the blkptrs we are losing better be unallocated */
668 			for (i = dn->dn_next_nblkptr[txgoff];
669 			    i < dnp->dn_nblkptr; i++)
670 				ASSERT(BP_IS_HOLE(&dnp->dn_blkptr[i]));
671 #endif
672 		}
673 		mutex_enter(&dn->dn_mtx);
674 		dnp->dn_nblkptr = dn->dn_next_nblkptr[txgoff];
675 		dn->dn_next_nblkptr[txgoff] = 0;
676 		mutex_exit(&dn->dn_mtx);
677 	}
678 
679 	if (dn->dn_next_nlevels[txgoff]) {
680 		dnode_increase_indirection(dn, tx);
681 		dn->dn_next_nlevels[txgoff] = 0;
682 	}
683 
684 	dbuf_sync_list(list, tx);
685 
686 	if (!DMU_OBJECT_IS_SPECIAL(dn->dn_object)) {
687 		ASSERT3P(list_head(list), ==, NULL);
688 		dnode_rele(dn, (void *)(uintptr_t)tx->tx_txg);
689 	}
690 
691 	/*
692 	 * Although we have dropped our reference to the dnode, it
693 	 * can't be evicted until its written, and we haven't yet
694 	 * initiated the IO for the dnode's dbuf.
695 	 */
696 }
697