--- a/usr/src/uts/common/fs/zfs/zio.c	Mon May 16 00:20:30 2011 +0100
+++ b/usr/src/uts/common/fs/zfs/zio.c	Wed Jul 27 07:13:44 2011 -0700
@@ -21,6 +21,7 @@
 /*
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2011 by Delphix. All rights reserved.
+ * Copyright (c) 2011 Nexenta Systems, Inc. All rights reserved.
  */
 
 #include <sys/zfs_context.h>
@@ -1061,7 +1062,7 @@
 {
 	spa_t *spa = zio->io_spa;
 	zio_type_t t = zio->io_type;
-	int flags = TQ_SLEEP | (cutinline ? TQ_FRONT : 0);
+	int flags = (cutinline ? TQ_FRONT : 0);
 
 	/*
 	 * If we're a config writer or a probe, the normal issue and
@@ -1085,8 +1086,15 @@
 		q++;
 
 	ASSERT3U(q, <, ZIO_TASKQ_TYPES);
-	(void) taskq_dispatch(spa->spa_zio_taskq[t][q],
-	    (task_func_t *)zio_execute, zio, flags);
+
+	/*
+	 * NB: We are assuming that the zio can only be dispatched
+	 * to a single taskq at a time.  It would be a grievous error
+	 * to dispatch the zio to another taskq at the same time.
+	 */
+	ASSERT(zio->io_tqent.tqent_next == NULL);
+	taskq_dispatch_ent(spa->spa_zio_taskq[t][q],
+	    (task_func_t *)zio_execute, zio, flags, &zio->io_tqent);
 }
 
 static boolean_t
@@ -2889,9 +2897,11 @@
 			 * Reexecution is potentially a huge amount of work.
 			 * Hand it off to the otherwise-unused claim taskq.
 			 */
-			(void) taskq_dispatch(
+			ASSERT(zio->io_tqent.tqent_next == NULL);
+			(void) taskq_dispatch_ent(
 			    spa->spa_zio_taskq[ZIO_TYPE_CLAIM][ZIO_TASKQ_ISSUE],
-			    (task_func_t *)zio_reexecute, zio, TQ_SLEEP);
+			    (task_func_t *)zio_reexecute, zio, 0,
+			    &zio->io_tqent);
 		}
 		return (ZIO_PIPELINE_STOP);
 	}