diff --git a/module/zfs/zio.c b/module/zfs/zio.c
index 2e8bf8664d..a7d8b03c5a 100644
--- a/module/zfs/zio.c
+++ b/module/zfs/zio.c
@@ -1073,8 +1073,9 @@ zio_taskq_dispatch(zio_t *zio, enum zio_taskq_type q, boolean_t cutinline)
 		q++;
 
 	ASSERT3U(q, <, ZIO_TASKQ_TYPES);
-	(void) taskq_dispatch(spa->spa_zio_taskq[t][q],
-	    (task_func_t *)zio_execute, zio, flags);
+
+	while (taskq_dispatch(spa->spa_zio_taskq[t][q],
+	    (task_func_t *)zio_execute, zio, flags) == 0); /* do nothing */
 }
 
 static boolean_t
diff --git a/scripts/zconfig.sh b/scripts/zconfig.sh
index b74c57087a..a34e656daa 100755
--- a/scripts/zconfig.sh
+++ b/scripts/zconfig.sh
@@ -120,7 +120,7 @@ zconfig_test3() {
 	TMP_FILE1=`mktemp`
 	TMP_CACHE=`mktemp -p /tmp zpool.cache.XXXXXXXX`
 
-	echo -n "test 3 - ZVOL sanity: "
+	echo -n "test 3 - zvol+ext3 sanity: "
 
 	# Create a pool and volume.
 	${ZFS_SH} zfs="spa_config_path=${TMP_CACHE}" || fail 1
@@ -129,7 +129,7 @@ zconfig_test3() {
 
 	# Partition the volume, for a 400M volume there will be
 	# 812 cylinders, 16 heads, and 63 sectors per track.
-	/sbin/sfdisk -q /dev/${FULL_NAME} << EOF &>${TMP_FILE1} || fail 4
+	/sbin/sfdisk -q /dev/zvol/${FULL_NAME} << EOF &>${TMP_FILE1} || fail 4
 ,812
 ;
 ;
@@ -137,11 +137,11 @@ zconfig_test3() {
 EOF
 
 	# Format the partition with ext3.
-	/sbin/mkfs.ext3 /dev/${FULL_NAME}1 &>${TMP_FILE1} || fail 5
+	/sbin/mkfs.ext3 /dev/zvol/${FULL_NAME}1 &>${TMP_FILE1} || fail 5
 
 	# Mount the ext3 filesystem and copy some data to it.
 	mkdir -p /tmp/${ZVOL_NAME} || fail 6
-	mount /dev/${FULL_NAME}1 /tmp/${ZVOL_NAME} || fail 7
+	mount /dev/zvol/${FULL_NAME}1 /tmp/${ZVOL_NAME} || fail 7
 	cp -RL ${SRC_DIR} /tmp/${ZVOL_NAME} || fail 8
 
 	# Verify the copied files match the original files.
@@ -159,4 +159,122 @@ EOF
 }
 zconfig_test3
 
+# zpool import/export device check (1 volume, 1 snapshot, 1 clone)
+zconfig_test4() {
+	POOL_NAME=tank
+	ZVOL_NAME=volume
+	SNAP_NAME=snapshot
+	CLONE_NAME=clone
+	FULL_ZVOL_NAME=${POOL_NAME}/${ZVOL_NAME}
+	FULL_SNAP_NAME=${POOL_NAME}/${ZVOL_NAME}@${SNAP_NAME}
+	FULL_CLONE_NAME=${POOL_NAME}/${CLONE_NAME}
+	TMP_CACHE=`mktemp -p /tmp zpool.cache.XXXXXXXX`
+
+	echo -n "test 4 - zpool import/export device: "
+
+	# Create a pool, volume, snapshot, and clone
+	${ZFS_SH} zfs="spa_config_path=${TMP_CACHE}" || fail 1
+	${ZPOOL_CREATE_SH} -p ${POOL_NAME} -c lo-raidz2 || fail 2
+	${ZFS} create -V 100M ${FULL_ZVOL_NAME} || fail 3
+	${ZFS} snapshot ${FULL_SNAP_NAME} || fail 4
+	${ZFS} clone ${FULL_SNAP_NAME} ${FULL_CLONE_NAME} || fail 5
+
+	# Verify the devices were created
+	stat /dev/zvol/${POOL_NAME} &>/dev/null || fail 6
+	stat /dev/zvol/${FULL_ZVOL_NAME} &>/dev/null || fail 7
+	stat /dev/zvol/${FULL_SNAP_NAME} &>/dev/null || fail 8
+	stat /dev/zvol/${FULL_CLONE_NAME} &>/dev/null || fail 9
+
+	# Export the pool
+	${ZPOOL} export ${POOL_NAME} || fail 10
+
+	# Verify the devices were removed
+	stat /dev/zvol/${POOL_NAME} &>/dev/null && fail 11
+	stat /dev/zvol/${FULL_ZVOL_NAME} &>/dev/null && fail 12
+	stat /dev/zvol/${FULL_SNAP_NAME} &>/dev/null && fail 13
+	stat /dev/zvol/${FULL_CLONE_NAME} &>/dev/null && fail 14
+
+	# Import the pool, wait 1 second for udev
+	${ZPOOL} import ${POOL_NAME} && sleep 1 || fail 15
+
+	# Verify the devices were created
+	stat /dev/zvol/${POOL_NAME} &>/dev/null || fail 16
+	stat /dev/zvol/${FULL_ZVOL_NAME} &>/dev/null || fail 17
+	stat /dev/zvol/${FULL_SNAP_NAME} &>/dev/null || fail 18
+	stat /dev/zvol/${FULL_CLONE_NAME} &>/dev/null || fail 19
+
+	# Destroy the pool and consequently the devices
+	${ZPOOL_CREATE_SH} -p ${POOL_NAME} -c lo-raidz2 -d || fail 20
+
+	# Verify the devices were removed
+	stat /dev/zvol/${POOL_NAME} &>/dev/null && fail 21
+	stat /dev/zvol/${FULL_ZVOL_NAME} &>/dev/null && fail 22
+	stat /dev/zvol/${FULL_SNAP_NAME} &>/dev/null && fail 23
+	stat /dev/zvol/${FULL_CLONE_NAME} &>/dev/null && fail 24
+
+	${ZFS_SH} -u || fail 25
+
+	pass
+}
+zconfig_test4
+
+# zpool insmod/rmmod device check (1 volume, 1 snapshot, 1 clone)
+zconfig_test5() {
+	POOL_NAME=tank
+	ZVOL_NAME=volume
+	SNAP_NAME=snapshot
+	CLONE_NAME=clone
+	FULL_ZVOL_NAME=${POOL_NAME}/${ZVOL_NAME}
+	FULL_SNAP_NAME=${POOL_NAME}/${ZVOL_NAME}@${SNAP_NAME}
+	FULL_CLONE_NAME=${POOL_NAME}/${CLONE_NAME}
+	TMP_CACHE=`mktemp -p /tmp zpool.cache.XXXXXXXX`
+
+	echo -n "test 5 - zpool insmod/rmmod device: "
+
+	# Create a pool, volume, snapshot, and clone
+	${ZFS_SH} zfs="spa_config_path=${TMP_CACHE}" || fail 1
+	${ZPOOL_CREATE_SH} -p ${POOL_NAME} -c lo-raidz2 || fail 2
+	${ZFS} create -V 100M ${FULL_ZVOL_NAME} || fail 3
+	${ZFS} snapshot ${FULL_SNAP_NAME} || fail 4
+	${ZFS} clone ${FULL_SNAP_NAME} ${FULL_CLONE_NAME} || fail 5
+
+	# Verify the devices were created
+	stat /dev/zvol/${POOL_NAME} &>/dev/null || fail 6
+	stat /dev/zvol/${FULL_ZVOL_NAME} &>/dev/null || fail 7
+	stat /dev/zvol/${FULL_SNAP_NAME} &>/dev/null || fail 8
+	stat /dev/zvol/${FULL_CLONE_NAME} &>/dev/null || fail 9
+
+	# Unload the modules
+	${ZFS_SH} -u || fail 10
+
+	# Verify the devices were removed
+	stat /dev/zvol/${POOL_NAME} &>/dev/null && fail 11
+	stat /dev/zvol/${FULL_ZVOL_NAME} &>/dev/null && fail 12
+	stat /dev/zvol/${FULL_SNAP_NAME} &>/dev/null && fail 13
+	stat /dev/zvol/${FULL_CLONE_NAME} &>/dev/null && fail 14
+
+	# Load the modules, wait 1 second for udev
+	${ZFS_SH} zfs="spa_config_path=${TMP_CACHE}" && sleep 1 || fail 15
+
+	# Verify the devices were created
+	stat /dev/zvol/${POOL_NAME} &>/dev/null || fail 16
+	stat /dev/zvol/${FULL_ZVOL_NAME} &>/dev/null || fail 17
+	stat /dev/zvol/${FULL_SNAP_NAME} &>/dev/null || fail 18
+	stat /dev/zvol/${FULL_CLONE_NAME} &>/dev/null || fail 19
+
+	# Destroy the pool and consequently the devices
+	${ZPOOL_CREATE_SH} -p ${POOL_NAME} -c lo-raidz2 -d || fail 20
+
+	# Verify the devices were removed
+	stat /dev/zvol/${POOL_NAME} &>/dev/null && fail 21
+	stat /dev/zvol/${FULL_ZVOL_NAME} &>/dev/null && fail 22
+	stat /dev/zvol/${FULL_SNAP_NAME} &>/dev/null && fail 23
+	stat /dev/zvol/${FULL_CLONE_NAME} &>/dev/null && fail 24
+
+	${ZFS_SH} -u || fail 25
+
+	pass
+}
+zconfig_test5
+
 exit 0
diff --git a/scripts/zpool-config/file-raid0.sh b/scripts/zpool-config/file-raid0.sh
index 14429c43d9..5ec80b05c1 100644
--- a/scripts/zpool-config/file-raid0.sh
+++ b/scripts/zpool-config/file-raid0.sh
@@ -12,8 +12,8 @@ zpool_create() {
 	for FILE in ${FILES}; do
 		msg "Creating ${FILE}"
 		rm -f ${FILE} || exit 1
-		dd if=/dev/zero of=${FILE} bs=1024k count=256 &>/dev/null ||
-			die "Error $? creating ${FILE}"
+		dd if=/dev/zero of=${FILE} bs=1024k count=0 seek=256 \
+			&>/dev/null || die "Error $? creating ${FILE}"
 	done
 
 	msg ${ZPOOL} create ${FORCE_FLAG} ${ZPOOL_NAME} ${FILES}
diff --git a/scripts/zpool-config/file-raid10.sh b/scripts/zpool-config/file-raid10.sh
index a632a4f4cd..ae7f0ae07b 100644
--- a/scripts/zpool-config/file-raid10.sh
+++ b/scripts/zpool-config/file-raid10.sh
@@ -13,8 +13,8 @@ zpool_create() {
 	for FILE in ${FILES}; do
 		msg "Creating ${FILE}"
 		rm -f ${FILE} || exit 1
-		dd if=/dev/zero of=${FILE} bs=1024k count=256 &>/dev/null ||
-			die "Error $? creating ${FILE}"
+		dd if=/dev/zero of=${FILE} bs=1024k count=0 seek=256 \
+			&>/dev/null || die "Error $? creating ${FILE}"
 	done
 
 	msg ${ZPOOL} create ${FORCE_FLAG} ${ZPOOL_NAME} \
diff --git a/scripts/zpool-config/file-raidz.sh b/scripts/zpool-config/file-raidz.sh
index 9302c85e97..5b6c3ea2c2 100644
--- a/scripts/zpool-config/file-raidz.sh
+++ b/scripts/zpool-config/file-raidz.sh
@@ -12,8 +12,8 @@ zpool_create() {
 	for FILE in ${FILES}; do
 		msg "Creating ${FILE}"
 		rm -f ${FILE} || exit 1
-		dd if=/dev/zero of=${FILE} bs=1024k count=256 &>/dev/null ||
-			die "Error $? creating ${FILE}"
+		dd if=/dev/zero of=${FILE} bs=1024k count=0 seek=256 \
+			&>/dev/null || die "Error $? creating ${FILE}"
 	done
 
 	msg ${ZPOOL} create ${FORCE_FLAG} ${ZPOOL_NAME} raidz ${FILES}
diff --git a/scripts/zpool-config/file-raidz2.sh b/scripts/zpool-config/file-raidz2.sh
index 681352783c..bc0e5ec8af 100644
--- a/scripts/zpool-config/file-raidz2.sh
+++ b/scripts/zpool-config/file-raidz2.sh
@@ -12,8 +12,8 @@ zpool_create() {
 	for FILE in ${FILES}; do
 		msg "Creating ${FILE}"
 		rm -f ${FILE} || exit 1
-		dd if=/dev/zero of=${FILE} bs=1024k count=256 &>/dev/null ||
-			die "Error $? creating ${FILE}"
+		dd if=/dev/zero of=${FILE} bs=1024k count=0 seek=256 \
+			&>/dev/null || die "Error $? creating ${FILE}"
 	done
 
 	msg ${ZPOOL} create ${FORCE_FLAG} ${ZPOOL_NAME} raidz2 ${FILES}
diff --git a/scripts/zpool-config/lo-raid0.sh b/scripts/zpool-config/lo-raid0.sh
index d37d5138f7..321d9b1f71 100644
--- a/scripts/zpool-config/lo-raid0.sh
+++ b/scripts/zpool-config/lo-raid0.sh
@@ -14,8 +14,8 @@ zpool_create() {
 		DEVICE=`unused_loop_device`
 		msg "Creating ${FILE} using loopback device ${DEVICE}"
 		rm -f ${FILE} || exit 1
-		dd if=/dev/zero of=${FILE} bs=1024k count=256 &>/dev/null ||
-			die "Error $? creating ${FILE}"
+		dd if=/dev/zero of=${FILE} bs=1024k count=0 seek=256 \
+			&>/dev/null || die "Error $? creating ${FILE}"
 		${LOSETUP} ${DEVICE} ${FILE} ||
 			die "Error $? creating ${FILE} -> ${DEVICE} loopback"
 		DEVICES="${DEVICES} ${DEVICE}"
diff --git a/scripts/zpool-config/lo-raid10.sh b/scripts/zpool-config/lo-raid10.sh
index 8d3672dd1b..f9c47cd1e1 100644
--- a/scripts/zpool-config/lo-raid10.sh
+++ b/scripts/zpool-config/lo-raid10.sh
@@ -16,8 +16,8 @@ zpool_create() {
 		DEVICE=`unused_loop_device`
 		msg "Creating ${FILE} using loopback device ${DEVICE}"
 		rm -f ${FILE} || exit 1
-		dd if=/dev/zero of=${FILE} bs=1024k count=256 &>/dev/null ||
-			die "Error $? creating ${FILE}"
+		dd if=/dev/zero of=${FILE} bs=1024k count=0 seek=256 \
+			&>/dev/null || die "Error $? creating ${FILE}"
 		${LOSETUP} ${DEVICE} ${FILE} ||
 			die "Error $? creating ${FILE} -> ${DEVICE} loopback"
 		DEVICES_M1="${DEVICES_M1} ${DEVICE}"
@@ -27,8 +27,8 @@ zpool_create() {
 		DEVICE=`unused_loop_device`
 		msg "Creating ${FILE} using loopback device ${DEVICE}"
 		rm -f ${FILE} || exit 1
-		dd if=/dev/zero of=${FILE} bs=1024k count=256 &>/dev/null ||
-			die "Error $? creating ${FILE}"
+		dd if=/dev/zero of=${FILE} bs=1024k count=0 seek=256 \
+			&>/dev/null || die "Error $? creating ${FILE}"
 		${LOSETUP} ${DEVICE} ${FILE} ||
 			die "Error $? creating ${FILE} -> ${DEVICE} loopback"
 		DEVICES_M2="${DEVICES_M2} ${DEVICE}"
diff --git a/scripts/zpool-config/lo-raidz.sh b/scripts/zpool-config/lo-raidz.sh
index 6efcd1041a..509f6ee1d7 100644
--- a/scripts/zpool-config/lo-raidz.sh
+++ b/scripts/zpool-config/lo-raidz.sh
@@ -14,8 +14,8 @@ zpool_create() {
 		DEVICE=`unused_loop_device`
 		msg "Creating ${FILE} using loopback device ${DEVICE}"
 		rm -f ${FILE} || exit 1
-		dd if=/dev/zero of=${FILE} bs=1024k count=256 &>/dev/null ||
-			die "Error $? creating ${FILE}"
+		dd if=/dev/zero of=${FILE} bs=1024k count=0 seek=256 \
+			&>/dev/null || die "Error $? creating ${FILE}"
 		${LOSETUP} ${DEVICE} ${FILE} ||
 			die "Error $? creating ${FILE} -> ${DEVICE} loopback"
 		DEVICES="${DEVICES} ${DEVICE}"
diff --git a/scripts/zpool-config/lo-raidz2.sh b/scripts/zpool-config/lo-raidz2.sh
index f59c7f2d65..6e61293c0b 100644
--- a/scripts/zpool-config/lo-raidz2.sh
+++ b/scripts/zpool-config/lo-raidz2.sh
@@ -14,8 +14,8 @@ zpool_create() {
 		DEVICE=`unused_loop_device`
 		msg "Creating ${FILE} using loopback device ${DEVICE}"
 		rm -f ${FILE} || exit 1
-		dd if=/dev/zero of=${FILE} bs=1024k count=256 &>/dev/null ||
-			die "Error $? creating ${FILE}"
+		dd if=/dev/zero of=${FILE} bs=1024k count=0 seek=256 \
+			&>/dev/null || die "Error $? creating ${FILE}"
 		${LOSETUP} ${DEVICE} ${FILE} ||
 			die "Error $? creating ${FILE} -> ${DEVICE} loopback"
 		DEVICES="${DEVICES} ${DEVICE}"