--- a/usr/src/uts/common/fs/zfs/dsl_dataset.c	Sat Aug 18 05:52:16 2012 -0500
+++ b/usr/src/uts/common/fs/zfs/dsl_dataset.c	Tue Aug 21 04:36:41 2012 -0700
@@ -103,14 +103,8 @@
 	ASSERT(BP_GET_TYPE(bp) != DMU_OT_NONE);
 	ASSERT(DMU_OT_IS_VALID(BP_GET_TYPE(bp)));
 	if (ds == NULL) {
-		/*
-		 * Account for the meta-objset space in its placeholder
-		 * dsl_dir.
-		 */
-		ASSERT3U(compressed, ==, uncompressed); /* it's all metadata */
-		dsl_dir_diduse_space(tx->tx_pool->dp_mos_dir, DD_USED_HEAD,
-		    used, compressed, uncompressed, tx);
-		dsl_dir_dirty(tx->tx_pool->dp_mos_dir, tx);
+		dsl_pool_mos_diduse_space(tx->tx_pool,
+		    used, compressed, uncompressed);
 		return;
 	}
 	dmu_buf_will_dirty(ds->ds_dbuf, tx);
@@ -146,15 +140,9 @@
 
 	ASSERT(used > 0);
 	if (ds == NULL) {
-		/*
-		 * Account for the meta-objset space in its placeholder
-		 * dataset.
-		 */
 		dsl_free(tx->tx_pool, tx->tx_txg, bp);
-
-		dsl_dir_diduse_space(tx->tx_pool->dp_mos_dir, DD_USED_HEAD,
-		    -used, -compressed, -uncompressed, tx);
-		dsl_dir_dirty(tx->tx_pool->dp_mos_dir, tx);
+		dsl_pool_mos_diduse_space(tx->tx_pool,
+		    -used, -compressed, -uncompressed);
 		return (used);
 	}
 	ASSERT3P(tx->tx_pool, ==, ds->ds_dir->dd_pool);
@@ -1068,26 +1056,26 @@
 
 	dd = ds->ds_dir;
 
-	/*
-	 * Check for errors and mark this ds as inconsistent, in
-	 * case we crash while freeing the objects.
-	 */
-	err = dsl_sync_task_do(dd->dd_pool, dsl_dataset_destroy_begin_check,
-	    dsl_dataset_destroy_begin_sync, ds, NULL, 0);
-	if (err)
-		goto out;
-
-	err = dmu_objset_from_ds(ds, &os);
-	if (err)
-		goto out;
-
-	/*
-	 * If async destruction is not enabled try to remove all objects
-	 * while in the open context so that there is less work to do in
-	 * the syncing context.
-	 */
 	if (!spa_feature_is_enabled(dsl_dataset_get_spa(ds),
 	    &spa_feature_table[SPA_FEATURE_ASYNC_DESTROY])) {
+		/*
+		 * Check for errors and mark this ds as inconsistent, in
+		 * case we crash while freeing the objects.
+		 */
+		err = dsl_sync_task_do(dd->dd_pool,
+		    dsl_dataset_destroy_begin_check,
+		    dsl_dataset_destroy_begin_sync, ds, NULL, 0);
+		if (err)
+			goto out;
+
+		err = dmu_objset_from_ds(ds, &os);
+		if (err)
+			goto out;
+
+		/*
+		 * Remove all objects while in the open context so that
+		 * there is less work to do in the syncing context.
+		 */
 		for (obj = 0; err == 0; err = dmu_object_next(os, &obj, FALSE,
 		    ds->ds_phys->ds_prev_snap_txg)) {
 			/*
@@ -1098,30 +1086,25 @@
 		}
 		if (err != ESRCH)
 			goto out;
-	}
-
-	/*
-	 * Only the ZIL knows how to free log blocks.
-	 */
-	zil_destroy(dmu_objset_zil(os), B_FALSE);
-
-	/*
-	 * Sync out all in-flight IO.
-	 */
-	txg_wait_synced(dd->dd_pool, 0);
-
-	/*
-	 * If we managed to free all the objects in open
-	 * context, the user space accounting should be zero.
-	 */
-	if (ds->ds_phys->ds_bp.blk_fill == 0 &&
-	    dmu_objset_userused_enabled(os)) {
-		uint64_t count;
-
-		ASSERT(zap_count(os, DMU_USERUSED_OBJECT, &count) != 0 ||
-		    count == 0);
-		ASSERT(zap_count(os, DMU_GROUPUSED_OBJECT, &count) != 0 ||
-		    count == 0);
+
+		/*
+		 * Sync out all in-flight IO.
+		 */
+		txg_wait_synced(dd->dd_pool, 0);
+
+		/*
+		 * If we managed to free all the objects in open
+		 * context, the user space accounting should be zero.
+		 */
+		if (ds->ds_phys->ds_bp.blk_fill == 0 &&
+		    dmu_objset_userused_enabled(os)) {
+			uint64_t count;
+
+			ASSERT(zap_count(os, DMU_USERUSED_OBJECT,
+			    &count) != 0 || count == 0);
+			ASSERT(zap_count(os, DMU_GROUPUSED_OBJECT,
+			    &count) != 0 || count == 0);
+		}
 	}
 
 	rw_enter(&dd->dd_pool->dp_config_rwlock, RW_READER);
@@ -1859,6 +1842,7 @@
 	} else {
 		zfeature_info_t *async_destroy =
 		    &spa_feature_table[SPA_FEATURE_ASYNC_DESTROY];
+		objset_t *os;
 
 		/*
 		 * There's no next snapshot, so this is a head dataset.
@@ -1870,6 +1854,8 @@
 		dsl_deadlist_free(mos, ds->ds_phys->ds_deadlist_obj, tx);
 		ds->ds_phys->ds_deadlist_obj = 0;
 
+		VERIFY3U(0, ==, dmu_objset_from_ds(ds, &os));
+
 		if (!spa_feature_is_enabled(dp->dp_spa, async_destroy)) {
 			err = old_synchronous_dataset_destroy(ds, tx);
 		} else {
@@ -1879,12 +1865,12 @@
 			 */
 			uint64_t used, comp, uncomp;
 
-			ASSERT(err == 0 || err == EBUSY);
+			zil_destroy_sync(dmu_objset_zil(os), tx);
+
 			if (!spa_feature_is_active(dp->dp_spa, async_destroy)) {
 				spa_feature_incr(dp->dp_spa, async_destroy, tx);
-				dp->dp_bptree_obj = bptree_alloc(
-				    dp->dp_meta_objset, tx);
-				VERIFY(zap_add(dp->dp_meta_objset,
+				dp->dp_bptree_obj = bptree_alloc(mos, tx);
+				VERIFY(zap_add(mos,
 				    DMU_POOL_DIRECTORY_OBJECT,
 				    DMU_POOL_BPTREE_OBJ, sizeof (uint64_t), 1,
 				    &dp->dp_bptree_obj, tx) == 0);
@@ -1897,7 +1883,7 @@
 			ASSERT(!DS_UNIQUE_IS_ACCURATE(ds) ||
 			    ds->ds_phys->ds_unique_bytes == used);
 
-			bptree_add(dp->dp_meta_objset, dp->dp_bptree_obj,
+			bptree_add(mos, dp->dp_bptree_obj,
 			    &ds->ds_phys->ds_bp, ds->ds_phys->ds_prev_snap_txg,
 			    used, comp, uncomp, tx);
 			dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD,
@@ -2179,7 +2165,6 @@
 	dmu_buf_will_dirty(ds->ds_dbuf, tx);
 	ds->ds_phys->ds_fsid_guid = ds->ds_fsid_guid;
 
-	dsl_dir_dirty(ds->ds_dir, tx);
 	dmu_objset_sync(ds->ds_objset, zio, tx);
 }