6841 Undirty freed spill blocks
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed by: Dan McDonald <danmcd@omniti.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>

@@ -906,21 +906,23 @@
 {
         dmu_buf_impl_t db_search;
         dmu_buf_impl_t *db, *db_next;
         uint64_t txg = tx->tx_txg;
         avl_index_t where;
+        boolean_t freespill =
+            (start_blkid == DMU_SPILL_BLKID || end_blkid == DMU_SPILL_BLKID);
 
-        if (end_blkid > dn->dn_maxblkid && (end_blkid != DMU_SPILL_BLKID))
+        if (end_blkid > dn->dn_maxblkid && !freespill)
                 end_blkid = dn->dn_maxblkid;
         dprintf_dnode(dn, "start=%llu end=%llu\n", start_blkid, end_blkid);
 
         db_search.db_level = 0;
         db_search.db_blkid = start_blkid;
         db_search.db_state = DB_SEARCH;
 
         mutex_enter(&dn->dn_dbufs_mtx);
-        if (start_blkid >= dn->dn_unlisted_l0_blkid) {
+        if (start_blkid >= dn->dn_unlisted_l0_blkid && !freespill) {
                 /* There can't be any dbufs in this range; no need to search. */
 #ifdef DEBUG
                 db = avl_find(&dn->dn_dbufs, &db_search, &where);
                 ASSERT3P(db, ==, NULL);
                 db = avl_nearest(&dn->dn_dbufs, where, AVL_AFTER);