zed: update zed.d/statechange-slot_off.sh

The statechange-slot_off.sh zedlet which was added in #15200
needed to be installed so it's included by the packages.

Additional testing has also shown that multiple retries are
often neeeded for the script to operate reliably.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>

cmd/zed/zed.d/Makefile.am

@@ -16,6 +16,7 @@ dist_zedexec_SCRIPTS = \
 	%D%/scrub_finish-notify.sh \
 	%D%/statechange-led.sh \
 	%D%/statechange-notify.sh \
+	%D%/statechange-slot_off.sh \
 	%D%/trim_finish-notify.sh \
 	%D%/vdev_attach-led.sh \
 	%D%/vdev_clear-led.sh
@@ -35,6 +36,7 @@ zedconfdefaults = \
 	scrub_finish-notify.sh \
 	statechange-led.sh \
 	statechange-notify.sh \
+	statechange-slot_off.sh \
 	vdev_attach-led.sh \
 	vdev_clear-led.sh
 

cmd/zed/zed.d/statechange-slot_off.sh

@@ -43,15 +43,17 @@ if [ ! -f "$ZEVENT_VDEV_ENC_SYSFS_PATH/power_status" ] ; then
 	exit 4
 fi
 
-echo "off" | tee "$ZEVENT_VDEV_ENC_SYSFS_PATH/power_status"
-
-# Wait for sysfs for report that the slot is off.  It can take ~400ms on some
-# enclosures.
+# Turn off the slot and wait for sysfs to report that the slot is off.
+# It can take ~400ms on some enclosures and multiple retries may be needed.
 for i in $(seq 1 20) ; do
-	if [ "$(cat $ZEVENT_VDEV_ENC_SYSFS_PATH/power_status)" == "off" ] ; then
-		break
-	fi
-	sleep 0.1
+	echo "off" | tee "$ZEVENT_VDEV_ENC_SYSFS_PATH/power_status"
+
+	for j in $(seq 1 5) ; do
+		if [ "$(cat $ZEVENT_VDEV_ENC_SYSFS_PATH/power_status)" == "off" ] ; then
+			break 2
+		fi
+		sleep 0.1
+	done
 done
 
 if [ "$(cat $ZEVENT_VDEV_ENC_SYSFS_PATH/power_status)" != "off" ] ; then