Add trim_finish notify script for ZED

Allow users to configure notifications when TRIM operations are
completed on pools. Unlike resilver_finish and scrub_finish,
the trim_finish event is generated for each vdev in the pool
which was trimmed, so the script will generate a notification
for each one.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Kevin P. Fleming <kevin@km6g.us>
Closes #10491

cmd/zed/zed.d/Makefile.am

@@ -24,7 +24,8 @@ dist_zedexec_SCRIPTS = \
 	vdev_clear-led.sh \
 	vdev_attach-led.sh \
 	pool_import-led.sh \
-	resilver_finish-start-scrub.sh
+	resilver_finish-start-scrub.sh \
+	trim_finish-notify.sh
 
 nodist_zedexec_SCRIPTS = history_event-zfs-list-cacher.sh
 

cmd/zed/zed.d/trim_finish-notify.sh

@@ -0,0 +1,37 @@
+#!/bin/sh
+#
+# Send notification in response to a TRIM_FINISH. The event
+# will be received for each vdev in the pool which was trimmed.
+#
+# Exit codes:
+#   0: notification sent
+#   1: notification failed
+#   2: notification not configured
+#   9: internal error
+
+[ -f "${ZED_ZEDLET_DIR}/zed.rc" ] && . "${ZED_ZEDLET_DIR}/zed.rc"
+. "${ZED_ZEDLET_DIR}/zed-functions.sh"
+
+[ -n "${ZEVENT_POOL}" ] || exit 9
+[ -n "${ZEVENT_SUBCLASS}" ] || exit 9
+
+zed_check_cmd "${ZPOOL}" || exit 9
+
+umask 077
+note_subject="ZFS ${ZEVENT_SUBCLASS} event for ${ZEVENT_POOL} on $(hostname)"
+note_pathname="${TMPDIR:="/tmp"}/$(basename -- "$0").${ZEVENT_EID}.$$"
+{
+    echo "ZFS has finished a trim:"
+    echo
+    echo "   eid: ${ZEVENT_EID}"
+    echo " class: ${ZEVENT_SUBCLASS}"
+    echo "  host: $(hostname)"
+    echo "  time: ${ZEVENT_TIME_STRING}"
+
+    "${ZPOOL}" status -t "${ZEVENT_POOL}"
+
+} > "${note_pathname}"
+
+zed_notify "${note_subject}" "${note_pathname}"; rv=$?
+rm -f "${note_pathname}"
+exit "${rv}"