Add SMART disk error counts to UMA

send_boot_metrics

 #!/bin/sh
 
 # Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 FREQ=$(cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq)
 AWK_PROG='
   /Initial TSC value:/ {
     sub(".*Initial TSC value: ", "")
@@ skipping 17 matching lines @@
 #   report_disk_metrics <read-sectors> <write-sectors>
 report_disk_metrics() {
   metrics_client Platform.BootSectorsRead $1 1 1000000 50
   metrics_client Platform.BootSectorsWritten $2 1 10000 50
 }
 
 report_disk_metrics $(
   bootstat_get_last boot-complete read-sectors write-sectors)
 
 send_metrics_on_resume -b
+
+# Report disk health from SMART (S.M.A.R.T.) parameters.
+# The first printf avoids a newline in $smart.
+smart="$(/usr/sbin/smartctl -A $(/usr/bin/rootdev -d) | \
+  awk '
+/^187/ { printf "%d ", $10; }
+/^199/ { print $10; }
+')"
+# smart now contains two numbers, for instance "10 20".  Extract each number
+# using prefix and suffix substitutions.  This would less cryptic if dash had
+# arrays.
+metrics_client Platform.SmartUncorrectableErrors ${smart% *} 1 1000000 20
+metrics_client Platform.SmartTransferErrors      ${smart#* } 1 1000000 20