xref: /illumos-gate/usr/src/uts/common/fs/zfs/dnode_sync.c (revision 744947dc83c634d985ed3ad79ac9c5e28d1865fd)
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  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23  */
24 
25 #include <sys/zfs_context.h>
26 #include <sys/dbuf.h>
27 #include <sys/dnode.h>
28 #include <sys/dmu.h>
29 #include <sys/dmu_tx.h>
30 #include <sys/dmu_objset.h>
31 #include <sys/dsl_dataset.h>
32 #include <sys/spa.h>
33 
34 static void
35 dnode_increase_indirection(dnode_t *dn, dmu_tx_t *tx)
36 {
37 	dmu_buf_impl_t *db;
38 	int txgoff = tx->tx_txg & TXG_MASK;
39 	int nblkptr = dn->dn_phys->dn_nblkptr;
40 	int old_toplvl = dn->dn_phys->dn_nlevels - 1;
41 	int new_level = dn->dn_next_nlevels[txgoff];
42 	int i;
43 
44 	rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
45 
46 	/* this dnode can't be paged out because it's dirty */
47 	ASSERT(dn->dn_phys->dn_type != DMU_OT_NONE);
48 	ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock));
49 	ASSERT(new_level > 1 && dn->dn_phys->dn_nlevels > 0);
50 
51 	db = dbuf_hold_level(dn, dn->dn_phys->dn_nlevels, 0, FTAG);
52 	ASSERT(db != NULL);
53 
54 	dn->dn_phys->dn_nlevels = new_level;
55 	dprintf("os=%p obj=%llu, increase to %d\n", dn->dn_objset,
56 	    dn->dn_object, dn->dn_phys->dn_nlevels);
57 
58 	/* check for existing blkptrs in the dnode */
59 	for (i = 0; i < nblkptr; i++)
60 		if (!BP_IS_HOLE(&dn->dn_phys->dn_blkptr[i]))
61 			break;
62 	if (i != nblkptr) {
63 		/* transfer dnode's block pointers to new indirect block */
64 		(void) dbuf_read(db, NULL, DB_RF_MUST_SUCCEED|DB_RF_HAVESTRUCT);
65 		ASSERT(db->db.db_data);
66 		ASSERT(arc_released(db->db_buf));
67 		ASSERT3U(sizeof (blkptr_t) * nblkptr, <=, db->db.db_size);
68 		bcopy(dn->dn_phys->dn_blkptr, db->db.db_data,
69 		    sizeof (blkptr_t) * nblkptr);
70 		arc_buf_freeze(db->db_buf);
71 	}
72 
73 	/* set dbuf's parent pointers to new indirect buf */
74 	for (i = 0; i < nblkptr; i++) {
75 		dmu_buf_impl_t *child = dbuf_find(dn, old_toplvl, i);
76 
77 		if (child == NULL)
78 			continue;
79 #ifdef	DEBUG
80 		DB_DNODE_ENTER(child);
81 		ASSERT3P(DB_DNODE(child), ==, dn);
82 		DB_DNODE_EXIT(child);
83 #endif	/* DEBUG */
84 		if (child->db_parent && child->db_parent != dn->dn_dbuf) {
85 			ASSERT(child->db_parent->db_level == db->db_level);
86 			ASSERT(child->db_blkptr !=
87 			    &dn->dn_phys->dn_blkptr[child->db_blkid]);
88 			mutex_exit(&child->db_mtx);
89 			continue;
90 		}
91 		ASSERT(child->db_parent == NULL ||
92 		    child->db_parent == dn->dn_dbuf);
93 
94 		child->db_parent = db;
95 		dbuf_add_ref(db, child);
96 		if (db->db.db_data)
97 			child->db_blkptr = (blkptr_t *)db->db.db_data + i;
98 		else
99 			child->db_blkptr = NULL;
100 		dprintf_dbuf_bp(child, child->db_blkptr,
101 		    "changed db_blkptr to new indirect %s", "");
102 
103 		mutex_exit(&child->db_mtx);
104 	}
105 
106 	bzero(dn->dn_phys->dn_blkptr, sizeof (blkptr_t) * nblkptr);
107 
108 	dbuf_rele(db, FTAG);
109 
110 	rw_exit(&dn->dn_struct_rwlock);
111 }
112 
113 static int
114 free_blocks(dnode_t *dn, blkptr_t *bp, int num, dmu_tx_t *tx)
115 {
116 	dsl_dataset_t *ds = dn->dn_objset->os_dsl_dataset;
117 	uint64_t bytesfreed = 0;
118 	int i, blocks_freed = 0;
119 
120 	dprintf("ds=%p obj=%llx num=%d\n", ds, dn->dn_object, num);
121 
122 	for (i = 0; i < num; i++, bp++) {
123 		if (BP_IS_HOLE(bp))
124 			continue;
125 
126 		bytesfreed += dsl_dataset_block_kill(ds, bp, tx, B_FALSE);
127 		ASSERT3U(bytesfreed, <=, DN_USED_BYTES(dn->dn_phys));
128 		bzero(bp, sizeof (blkptr_t));
129 		blocks_freed += 1;
130 	}
131 	dnode_diduse_space(dn, -bytesfreed);
132 	return (blocks_freed);
133 }
134 
135 #ifdef ZFS_DEBUG
136 static void
137 free_verify(dmu_buf_impl_t *db, uint64_t start, uint64_t end, dmu_tx_t *tx)
138 {
139 	int off, num;
140 	int i, err, epbs;
141 	uint64_t txg = tx->tx_txg;
142 	dnode_t *dn;
143 
144 	DB_DNODE_ENTER(db);
145 	dn = DB_DNODE(db);
146 	epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT;
147 	off = start - (db->db_blkid * 1<<epbs);
148 	num = end - start + 1;
149 
150 	ASSERT3U(off, >=, 0);
151 	ASSERT3U(num, >=, 0);
152 	ASSERT3U(db->db_level, >, 0);
153 	ASSERT3U(db->db.db_size, ==, 1 << dn->dn_phys->dn_indblkshift);
154 	ASSERT3U(off+num, <=, db->db.db_size >> SPA_BLKPTRSHIFT);
155 	ASSERT(db->db_blkptr != NULL);
156 
157 	for (i = off; i < off+num; i++) {
158 		uint64_t *buf;
159 		dmu_buf_impl_t *child;
160 		dbuf_dirty_record_t *dr;
161 		int j;
162 
163 		ASSERT(db->db_level == 1);
164 
165 		rw_enter(&dn->dn_struct_rwlock, RW_READER);
166 		err = dbuf_hold_impl(dn, db->db_level-1,
167 		    (db->db_blkid << epbs) + i, TRUE, FTAG, &child);
168 		rw_exit(&dn->dn_struct_rwlock);
169 		if (err == ENOENT)
170 			continue;
171 		ASSERT(err == 0);
172 		ASSERT(child->db_level == 0);
173 		dr = child->db_last_dirty;
174 		while (dr && dr->dr_txg > txg)
175 			dr = dr->dr_next;
176 		ASSERT(dr == NULL || dr->dr_txg == txg);
177 
178 		/* data_old better be zeroed */
179 		if (dr) {
180 			buf = dr->dt.dl.dr_data->b_data;
181 			for (j = 0; j < child->db.db_size >> 3; j++) {
182 				if (buf[j] != 0) {
183 					panic("freed data not zero: "
184 					    "child=%p i=%d off=%d num=%d\n",
185 					    (void *)child, i, off, num);
186 				}
187 			}
188 		}
189 
190 		/*
191 		 * db_data better be zeroed unless it's dirty in a
192 		 * future txg.
193 		 */
194 		mutex_enter(&child->db_mtx);
195 		buf = child->db.db_data;
196 		if (buf != NULL && child->db_state != DB_FILL &&
197 		    child->db_last_dirty == NULL) {
198 			for (j = 0; j < child->db.db_size >> 3; j++) {
199 				if (buf[j] != 0) {
200 					panic("freed data not zero: "
201 					    "child=%p i=%d off=%d num=%d\n",
202 					    (void *)child, i, off, num);
203 				}
204 			}
205 		}
206 		mutex_exit(&child->db_mtx);
207 
208 		dbuf_rele(child, FTAG);
209 	}
210 	DB_DNODE_EXIT(db);
211 }
212 #endif
213 
214 #define	ALL -1
215 
216 static int
217 free_children(dmu_buf_impl_t *db, uint64_t blkid, uint64_t nblks, int trunc,
218     dmu_tx_t *tx)
219 {
220 	dnode_t *dn;
221 	blkptr_t *bp;
222 	dmu_buf_impl_t *subdb;
223 	uint64_t start, end, dbstart, dbend, i;
224 	int epbs, shift, err;
225 	int all = TRUE;
226 	int blocks_freed = 0;
227 
228 	/*
229 	 * There is a small possibility that this block will not be cached:
230 	 *   1 - if level > 1 and there are no children with level <= 1
231 	 *   2 - if we didn't get a dirty hold (because this block had just
232 	 *	 finished being written -- and so had no holds), and then this
233 	 *	 block got evicted before we got here.
234 	 */
235 	if (db->db_state != DB_CACHED)
236 		(void) dbuf_read(db, NULL, DB_RF_MUST_SUCCEED);
237 
238 	dbuf_release_bp(db);
239 	bp = (blkptr_t *)db->db.db_data;
240 
241 	DB_DNODE_ENTER(db);
242 	dn = DB_DNODE(db);
243 	epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT;
244 	shift = (db->db_level - 1) * epbs;
245 	dbstart = db->db_blkid << epbs;
246 	start = blkid >> shift;
247 	if (dbstart < start) {
248 		bp += start - dbstart;
249 		all = FALSE;
250 	} else {
251 		start = dbstart;
252 	}
253 	dbend = ((db->db_blkid + 1) << epbs) - 1;
254 	end = (blkid + nblks - 1) >> shift;
255 	if (dbend <= end)
256 		end = dbend;
257 	else if (all)
258 		all = trunc;
259 	ASSERT3U(start, <=, end);
260 
261 	if (db->db_level == 1) {
262 		FREE_VERIFY(db, start, end, tx);
263 		blocks_freed = free_blocks(dn, bp, end-start+1, tx);
264 		arc_buf_freeze(db->db_buf);
265 		ASSERT(all || blocks_freed == 0 || db->db_last_dirty);
266 		DB_DNODE_EXIT(db);
267 		return (all ? ALL : blocks_freed);
268 	}
269 
270 	for (i = start; i <= end; i++, bp++) {
271 		if (BP_IS_HOLE(bp))
272 			continue;
273 		rw_enter(&dn->dn_struct_rwlock, RW_READER);
274 		err = dbuf_hold_impl(dn, db->db_level-1, i, TRUE, FTAG, &subdb);
275 		ASSERT3U(err, ==, 0);
276 		rw_exit(&dn->dn_struct_rwlock);
277 
278 		if (free_children(subdb, blkid, nblks, trunc, tx) == ALL) {
279 			ASSERT3P(subdb->db_blkptr, ==, bp);
280 			blocks_freed += free_blocks(dn, bp, 1, tx);
281 		} else {
282 			all = FALSE;
283 		}
284 		dbuf_rele(subdb, FTAG);
285 	}
286 	DB_DNODE_EXIT(db);
287 	arc_buf_freeze(db->db_buf);
288 #ifdef ZFS_DEBUG
289 	bp -= (end-start)+1;
290 	for (i = start; i <= end; i++, bp++) {
291 		if (i == start && blkid != 0)
292 			continue;
293 		else if (i == end && !trunc)
294 			continue;
295 		ASSERT3U(bp->blk_birth, ==, 0);
296 	}
297 #endif
298 	ASSERT(all || blocks_freed == 0 || db->db_last_dirty);
299 	return (all ? ALL : blocks_freed);
300 }
301 
302 /*
303  * free_range: Traverse the indicated range of the provided file
304  * and "free" all the blocks contained there.
305  */
306 static void
307 dnode_sync_free_range(dnode_t *dn, uint64_t blkid, uint64_t nblks, dmu_tx_t *tx)
308 {
309 	blkptr_t *bp = dn->dn_phys->dn_blkptr;
310 	dmu_buf_impl_t *db;
311 	int trunc, start, end, shift, i, err;
312 	int dnlevel = dn->dn_phys->dn_nlevels;
313 
314 	if (blkid > dn->dn_phys->dn_maxblkid)
315 		return;
316 
317 	ASSERT(dn->dn_phys->dn_maxblkid < UINT64_MAX);
318 	trunc = blkid + nblks > dn->dn_phys->dn_maxblkid;
319 	if (trunc)
320 		nblks = dn->dn_phys->dn_maxblkid - blkid + 1;
321 
322 	/* There are no indirect blocks in the object */
323 	if (dnlevel == 1) {
324 		if (blkid >= dn->dn_phys->dn_nblkptr) {
325 			/* this range was never made persistent */
326 			return;
327 		}
328 		ASSERT3U(blkid + nblks, <=, dn->dn_phys->dn_nblkptr);
329 		(void) free_blocks(dn, bp + blkid, nblks, tx);
330 		if (trunc) {
331 			uint64_t off = (dn->dn_phys->dn_maxblkid + 1) *
332 			    (dn->dn_phys->dn_datablkszsec << SPA_MINBLOCKSHIFT);
333 			dn->dn_phys->dn_maxblkid = (blkid ? blkid - 1 : 0);
334 			ASSERT(off < dn->dn_phys->dn_maxblkid ||
335 			    dn->dn_phys->dn_maxblkid == 0 ||
336 			    dnode_next_offset(dn, 0, &off, 1, 1, 0) != 0);
337 		}
338 		return;
339 	}
340 
341 	shift = (dnlevel - 1) * (dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT);
342 	start = blkid >> shift;
343 	ASSERT(start < dn->dn_phys->dn_nblkptr);
344 	end = (blkid + nblks - 1) >> shift;
345 	bp += start;
346 	for (i = start; i <= end; i++, bp++) {
347 		if (BP_IS_HOLE(bp))
348 			continue;
349 		rw_enter(&dn->dn_struct_rwlock, RW_READER);
350 		err = dbuf_hold_impl(dn, dnlevel-1, i, TRUE, FTAG, &db);
351 		ASSERT3U(err, ==, 0);
352 		rw_exit(&dn->dn_struct_rwlock);
353 
354 		if (free_children(db, blkid, nblks, trunc, tx) == ALL) {
355 			ASSERT3P(db->db_blkptr, ==, bp);
356 			(void) free_blocks(dn, bp, 1, tx);
357 		}
358 		dbuf_rele(db, FTAG);
359 	}
360 	if (trunc) {
361 		uint64_t off = (dn->dn_phys->dn_maxblkid + 1) *
362 		    (dn->dn_phys->dn_datablkszsec << SPA_MINBLOCKSHIFT);
363 		dn->dn_phys->dn_maxblkid = (blkid ? blkid - 1 : 0);
364 		ASSERT(off < dn->dn_phys->dn_maxblkid ||
365 		    dn->dn_phys->dn_maxblkid == 0 ||
366 		    dnode_next_offset(dn, 0, &off, 1, 1, 0) != 0);
367 	}
368 }
369 
370 /*
371  * Try to kick all the dnodes dbufs out of the cache...
372  */
373 void
374 dnode_evict_dbufs(dnode_t *dn)
375 {
376 	int progress;
377 	int pass = 0;
378 
379 	do {
380 		dmu_buf_impl_t *db, marker;
381 		int evicting = FALSE;
382 
383 		progress = FALSE;
384 		mutex_enter(&dn->dn_dbufs_mtx);
385 		list_insert_tail(&dn->dn_dbufs, &marker);
386 		db = list_head(&dn->dn_dbufs);
387 		for (; db != &marker; db = list_head(&dn->dn_dbufs)) {
388 			list_remove(&dn->dn_dbufs, db);
389 			list_insert_tail(&dn->dn_dbufs, db);
390 #ifdef	DEBUG
391 			DB_DNODE_ENTER(db);
392 			ASSERT3P(DB_DNODE(db), ==, dn);
393 			DB_DNODE_EXIT(db);
394 #endif	/* DEBUG */
395 
396 			mutex_enter(&db->db_mtx);
397 			if (db->db_state == DB_EVICTING) {
398 				progress = TRUE;
399 				evicting = TRUE;
400 				mutex_exit(&db->db_mtx);
401 			} else if (refcount_is_zero(&db->db_holds)) {
402 				progress = TRUE;
403 				dbuf_clear(db); /* exits db_mtx for us */
404 			} else {
405 				mutex_exit(&db->db_mtx);
406 			}
407 
408 		}
409 		list_remove(&dn->dn_dbufs, &marker);
410 		/*
411 		 * NB: we need to drop dn_dbufs_mtx between passes so
412 		 * that any DB_EVICTING dbufs can make progress.
413 		 * Ideally, we would have some cv we could wait on, but
414 		 * since we don't, just wait a bit to give the other
415 		 * thread a chance to run.
416 		 */
417 		mutex_exit(&dn->dn_dbufs_mtx);
418 		if (evicting)
419 			delay(1);
420 		pass++;
421 		ASSERT(pass < 100); /* sanity check */
422 	} while (progress);
423 
424 	rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
425 	if (dn->dn_bonus && refcount_is_zero(&dn->dn_bonus->db_holds)) {
426 		mutex_enter(&dn->dn_bonus->db_mtx);
427 		dbuf_evict(dn->dn_bonus);
428 		dn->dn_bonus = NULL;
429 	}
430 	rw_exit(&dn->dn_struct_rwlock);
431 }
432 
433 static void
434 dnode_undirty_dbufs(list_t *list)
435 {
436 	dbuf_dirty_record_t *dr;
437 
438 	while (dr = list_head(list)) {
439 		dmu_buf_impl_t *db = dr->dr_dbuf;
440 		uint64_t txg = dr->dr_txg;
441 
442 		if (db->db_level != 0)
443 			dnode_undirty_dbufs(&dr->dt.di.dr_children);
444 
445 		mutex_enter(&db->db_mtx);
446 		/* XXX - use dbuf_undirty()? */
447 		list_remove(list, dr);
448 		ASSERT(db->db_last_dirty == dr);
449 		db->db_last_dirty = NULL;
450 		db->db_dirtycnt -= 1;
451 		if (db->db_level == 0) {
452 			ASSERT(db->db_blkid == DMU_BONUS_BLKID ||
453 			    dr->dt.dl.dr_data == db->db_buf);
454 			dbuf_unoverride(dr);
455 		}
456 		kmem_free(dr, sizeof (dbuf_dirty_record_t));
457 		dbuf_rele_and_unlock(db, (void *)(uintptr_t)txg);
458 	}
459 }
460 
461 static void
462 dnode_sync_free(dnode_t *dn, dmu_tx_t *tx)
463 {
464 	int txgoff = tx->tx_txg & TXG_MASK;
465 
466 	ASSERT(dmu_tx_is_syncing(tx));
467 
468 	/*
469 	 * Our contents should have been freed in dnode_sync() by the
470 	 * free range record inserted by the caller of dnode_free().
471 	 */
472 	ASSERT3U(DN_USED_BYTES(dn->dn_phys), ==, 0);
473 	ASSERT(BP_IS_HOLE(dn->dn_phys->dn_blkptr));
474 
475 	dnode_undirty_dbufs(&dn->dn_dirty_records[txgoff]);
476 	dnode_evict_dbufs(dn);
477 	ASSERT3P(list_head(&dn->dn_dbufs), ==, NULL);
478 
479 	/*
480 	 * XXX - It would be nice to assert this, but we may still
481 	 * have residual holds from async evictions from the arc...
482 	 *
483 	 * zfs_obj_to_path() also depends on this being
484 	 * commented out.
485 	 *
486 	 * ASSERT3U(refcount_count(&dn->dn_holds), ==, 1);
487 	 */
488 
489 	/* Undirty next bits */
490 	dn->dn_next_nlevels[txgoff] = 0;
491 	dn->dn_next_indblkshift[txgoff] = 0;
492 	dn->dn_next_blksz[txgoff] = 0;
493 
494 	/* ASSERT(blkptrs are zero); */
495 	ASSERT(dn->dn_phys->dn_type != DMU_OT_NONE);
496 	ASSERT(dn->dn_type != DMU_OT_NONE);
497 
498 	ASSERT(dn->dn_free_txg > 0);
499 	if (dn->dn_allocated_txg != dn->dn_free_txg)
500 		dbuf_will_dirty(dn->dn_dbuf, tx);
501 	bzero(dn->dn_phys, sizeof (dnode_phys_t));
502 
503 	mutex_enter(&dn->dn_mtx);
504 	dn->dn_type = DMU_OT_NONE;
505 	dn->dn_maxblkid = 0;
506 	dn->dn_allocated_txg = 0;
507 	dn->dn_free_txg = 0;
508 	dn->dn_have_spill = B_FALSE;
509 	mutex_exit(&dn->dn_mtx);
510 
511 	ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT);
512 
513 	dnode_rele(dn, (void *)(uintptr_t)tx->tx_txg);
514 	/*
515 	 * Now that we've released our hold, the dnode may
516 	 * be evicted, so we musn't access it.
517 	 */
518 }
519 
520 /*
521  * Write out the dnode's dirty buffers.
522  */
523 void
524 dnode_sync(dnode_t *dn, dmu_tx_t *tx)
525 {
526 	free_range_t *rp;
527 	dnode_phys_t *dnp = dn->dn_phys;
528 	int txgoff = tx->tx_txg & TXG_MASK;
529 	list_t *list = &dn->dn_dirty_records[txgoff];
530 	static const dnode_phys_t zerodn = { 0 };
531 	boolean_t kill_spill = B_FALSE;
532 
533 	ASSERT(dmu_tx_is_syncing(tx));
534 	ASSERT(dnp->dn_type != DMU_OT_NONE || dn->dn_allocated_txg);
535 	ASSERT(dnp->dn_type != DMU_OT_NONE ||
536 	    bcmp(dnp, &zerodn, DNODE_SIZE) == 0);
537 	DNODE_VERIFY(dn);
538 
539 	ASSERT(dn->dn_dbuf == NULL || arc_released(dn->dn_dbuf->db_buf));
540 
541 	if (dmu_objset_userused_enabled(dn->dn_objset) &&
542 	    !DMU_OBJECT_IS_SPECIAL(dn->dn_object)) {
543 		mutex_enter(&dn->dn_mtx);
544 		dn->dn_oldused = DN_USED_BYTES(dn->dn_phys);
545 		dn->dn_oldflags = dn->dn_phys->dn_flags;
546 		dn->dn_phys->dn_flags |= DNODE_FLAG_USERUSED_ACCOUNTED;
547 		mutex_exit(&dn->dn_mtx);
548 		dmu_objset_userquota_get_ids(dn, B_FALSE, tx);
549 	} else {
550 		/* Once we account for it, we should always account for it. */
551 		ASSERT(!(dn->dn_phys->dn_flags &
552 		    DNODE_FLAG_USERUSED_ACCOUNTED));
553 	}
554 
555 	mutex_enter(&dn->dn_mtx);
556 	if (dn->dn_allocated_txg == tx->tx_txg) {
557 		/* The dnode is newly allocated or reallocated */
558 		if (dnp->dn_type == DMU_OT_NONE) {
559 			/* this is a first alloc, not a realloc */
560 			dnp->dn_nlevels = 1;
561 			dnp->dn_nblkptr = dn->dn_nblkptr;
562 		}
563 
564 		dnp->dn_type = dn->dn_type;
565 		dnp->dn_bonustype = dn->dn_bonustype;
566 		dnp->dn_bonuslen = dn->dn_bonuslen;
567 	}
568 
569 	ASSERT(dnp->dn_nlevels > 1 ||
570 	    BP_IS_HOLE(&dnp->dn_blkptr[0]) ||
571 	    BP_GET_LSIZE(&dnp->dn_blkptr[0]) ==
572 	    dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT);
573 
574 	if (dn->dn_next_blksz[txgoff]) {
575 		ASSERT(P2PHASE(dn->dn_next_blksz[txgoff],
576 		    SPA_MINBLOCKSIZE) == 0);
577 		ASSERT(BP_IS_HOLE(&dnp->dn_blkptr[0]) ||
578 		    dn->dn_maxblkid == 0 || list_head(list) != NULL ||
579 		    avl_last(&dn->dn_ranges[txgoff]) ||
580 		    dn->dn_next_blksz[txgoff] >> SPA_MINBLOCKSHIFT ==
581 		    dnp->dn_datablkszsec);
582 		dnp->dn_datablkszsec =
583 		    dn->dn_next_blksz[txgoff] >> SPA_MINBLOCKSHIFT;
584 		dn->dn_next_blksz[txgoff] = 0;
585 	}
586 
587 	if (dn->dn_next_bonuslen[txgoff]) {
588 		if (dn->dn_next_bonuslen[txgoff] == DN_ZERO_BONUSLEN)
589 			dnp->dn_bonuslen = 0;
590 		else
591 			dnp->dn_bonuslen = dn->dn_next_bonuslen[txgoff];
592 		ASSERT(dnp->dn_bonuslen <= DN_MAX_BONUSLEN);
593 		dn->dn_next_bonuslen[txgoff] = 0;
594 	}
595 
596 	if (dn->dn_next_bonustype[txgoff]) {
597 		ASSERT(dn->dn_next_bonustype[txgoff] < DMU_OT_NUMTYPES);
598 		dnp->dn_bonustype = dn->dn_next_bonustype[txgoff];
599 		dn->dn_next_bonustype[txgoff] = 0;
600 	}
601 
602 	/*
603 	 * We will either remove a spill block when a file is being removed
604 	 * or we have been asked to remove it.
605 	 */
606 	if (dn->dn_rm_spillblk[txgoff] ||
607 	    ((dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) &&
608 	    dn->dn_free_txg > 0 && dn->dn_free_txg <= tx->tx_txg)) {
609 		if ((dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR))
610 			kill_spill = B_TRUE;
611 		dn->dn_rm_spillblk[txgoff] = 0;
612 	}
613 
614 	if (dn->dn_next_indblkshift[txgoff]) {
615 		ASSERT(dnp->dn_nlevels == 1);
616 		dnp->dn_indblkshift = dn->dn_next_indblkshift[txgoff];
617 		dn->dn_next_indblkshift[txgoff] = 0;
618 	}
619 
620 	/*
621 	 * Just take the live (open-context) values for checksum and compress.
622 	 * Strictly speaking it's a future leak, but nothing bad happens if we
623 	 * start using the new checksum or compress algorithm a little early.
624 	 */
625 	dnp->dn_checksum = dn->dn_checksum;
626 	dnp->dn_compress = dn->dn_compress;
627 
628 	mutex_exit(&dn->dn_mtx);
629 
630 	if (kill_spill) {
631 		(void) free_blocks(dn, &dn->dn_phys->dn_spill, 1, tx);
632 		mutex_enter(&dn->dn_mtx);
633 		dnp->dn_flags &= ~DNODE_FLAG_SPILL_BLKPTR;
634 		mutex_exit(&dn->dn_mtx);
635 	}
636 
637 	/* process all the "freed" ranges in the file */
638 	while (rp = avl_last(&dn->dn_ranges[txgoff])) {
639 		dnode_sync_free_range(dn, rp->fr_blkid, rp->fr_nblks, tx);
640 		/* grab the mutex so we don't race with dnode_block_freed() */
641 		mutex_enter(&dn->dn_mtx);
642 		avl_remove(&dn->dn_ranges[txgoff], rp);
643 		mutex_exit(&dn->dn_mtx);
644 		kmem_free(rp, sizeof (free_range_t));
645 	}
646 
647 	if (dn->dn_free_txg > 0 && dn->dn_free_txg <= tx->tx_txg) {
648 		dnode_sync_free(dn, tx);
649 		return;
650 	}
651 
652 	if (dn->dn_next_nblkptr[txgoff]) {
653 		/* this should only happen on a realloc */
654 		ASSERT(dn->dn_allocated_txg == tx->tx_txg);
655 		if (dn->dn_next_nblkptr[txgoff] > dnp->dn_nblkptr) {
656 			/* zero the new blkptrs we are gaining */
657 			bzero(dnp->dn_blkptr + dnp->dn_nblkptr,
658 			    sizeof (blkptr_t) *
659 			    (dn->dn_next_nblkptr[txgoff] - dnp->dn_nblkptr));
660 #ifdef ZFS_DEBUG
661 		} else {
662 			int i;
663 			ASSERT(dn->dn_next_nblkptr[txgoff] < dnp->dn_nblkptr);
664 			/* the blkptrs we are losing better be unallocated */
665 			for (i = dn->dn_next_nblkptr[txgoff];
666 			    i < dnp->dn_nblkptr; i++)
667 				ASSERT(BP_IS_HOLE(&dnp->dn_blkptr[i]));
668 #endif
669 		}
670 		mutex_enter(&dn->dn_mtx);
671 		dnp->dn_nblkptr = dn->dn_next_nblkptr[txgoff];
672 		dn->dn_next_nblkptr[txgoff] = 0;
673 		mutex_exit(&dn->dn_mtx);
674 	}
675 
676 	if (dn->dn_next_nlevels[txgoff]) {
677 		dnode_increase_indirection(dn, tx);
678 		dn->dn_next_nlevels[txgoff] = 0;
679 	}
680 
681 	dbuf_sync_list(list, tx);
682 
683 	if (!DMU_OBJECT_IS_SPECIAL(dn->dn_object)) {
684 		ASSERT3P(list_head(list), ==, NULL);
685 		dnode_rele(dn, (void *)(uintptr_t)tx->tx_txg);
686 	}
687 
688 	/*
689 	 * Although we have dropped our reference to the dnode, it
690 	 * can't be evicted until its written, and we haven't yet
691 	 * initiated the IO for the dnode's dbuf.
692 	 */
693 }
694