zfs/cmd/zed/zed.d/statechange-led.sh

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#!/bin/bash
#
# Turn off/on the VDEV's enclosure fault LEDs when the pool's state changes.
#
# Turn the VDEV's fault LED on if it becomes FAULTED, DEGRADED or UNAVAIL.
# Turn the LED off when it's back ONLINE again.
#
# This script run in two basic modes:
#
# 1. If $ZEVENT_VDEV_ENC_SYSFS_PATH and $ZEVENT_VDEV_STATE_STR are set, then
# only set the LED for that particular VDEV. This is the case for statechange
# events and some vdev_* events.
#
# 2. If those vars are not set, then check the state of all VDEVs in the pool,i
# and set the LEDs accordingly. This is the case for pool_import events.
#
# Note that this script requires that your enclosure be supported by the
# Linux SCSI enclosure services (ses) driver. The script will do nothing
# if you have no enclosure, or if your enclosure isn't supported.
#
# Exit codes:
# 0: enclosure led successfully set
# 1: enclosure leds not not available
# 2: enclosure leds administratively disabled
# 3: The led sysfs path passed from ZFS does not exist
# 4: $ZPOOL not set
[ -f "${ZED_ZEDLET_DIR}/zed.rc" ] && . "${ZED_ZEDLET_DIR}/zed.rc"
. "${ZED_ZEDLET_DIR}/zed-functions.sh"
if [ ! -d /sys/class/enclosure ] ; then
exit 1
fi
if [ "${ZED_USE_ENCLOSURE_LEDS}" != "1" ] ; then
exit 2
fi
zed_check_cmd "$ZPOOL" || exit 4
# Global used in set_led debug print
vdev=""
# set_led (file)
#
# Write an enclosure sysfs file
#
# Arguments
# file: sysfs file to set (like /sys/class/enclosure/0:0:1:0/SLOT 10/fault)
# val: value to set it to
#
# Globals
# vdev: VDEV name for debug printing
#
# Return
# nothing
#
function set_led {
file="$1"
val="$2"
# Set the value twice. I've seen enclosures that were
# flakey about setting it the first time.
echo "$val" > "$file"
echo "$val" > "$file"
zed_log_msg "vdev $vdev set '$file' LED to $val"
}
# check_and_set_led (file, val)
#
# Read an enclosure sysfs file, and write it if it's not already set to 'val'
#
# Arguments
# file: sysfs file to set (like /sys/class/enclosure/0:0:1:0/SLOT 10/fault)
# val: value to set it to
#
# Return
# 0 on success, 3 on missing sysfs path
#
function check_and_set_led
{
file="$1"
val="$2"
if [ ! -e "$ZEVENT_VDEV_ENC_SYSFS_PATH/fault" ] ; then
return 3
fi
# We want to check the current state first, since writing to the
# 'fault' entry always always causes a SES command, even if the
# current state is already what you want.
current=$(cat "${file}")
# On some enclosures if you write 1 to fault, and read it back,
# it will return 2. Treat all non-zero values as 1 for
# simplicity.
if [ "$current" != "0" ] ; then
current=1
fi
if [ "$current" != "$val" ] ; then
set_led "$file" "$val"
fi
}
function state_to_val {
state="$1"
if [ "$state" == "FAULTED" ] || [ "$state" == "DEGRADED" ] || \
[ "$state" == "UNAVAIL" ] ; then
echo 1
elif [ "$state" == "ONLINE" ] ; then
echo 0
fi
}
# process_pool ([pool])
#
# Iterate through a pool (or pools) and set the VDEV's enclosure slot LEDs to
# the VDEV's state.
#
# Arguments
# pool: Optional pool name. If not specified, iterate though all pools.
#
# Return
# 0 on success, 3 on missing sysfs path
#
function process_pool
{
pool="$1"
rc=0
# Lookup all the current LED values and paths in parallel
cmd='echo led_token=$(cat "$VDEV_ENC_SYSFS_PATH/fault"),"$VDEV_ENC_SYSFS_PATH",'
out=$($ZPOOL status -vc "$cmd" $pool | grep 'led_token=')
while read -r vdev state read write chksum therest ; do
# Read out current LED value and path
tmp=$(echo "$therest" | sed 's/^.*led_token=//g')
IFS="," read -r current_val vdev_enc_sysfs_path <<< "$tmp"
if [ -z "$vdev_enc_sysfs_path" ] ; then
# Skip anything with no sysfs LED entries
continue
fi
# On some enclosures if you write 1 to fault, and read it back,
# it will return 2. Treat all non-zero values as 1 for
# simplicity.
if [ "$current_val" != "0" ] ; then
current_val=1
fi
val=$(state_to_val "$state")
if [ "$current_val" == "$val" ] ; then
# LED is already set correctly
continue
fi
if [ ! -e "$vdev_enc_sysfs_path/fault" ] ; then
rc=1
zed_log_msg "vdev $vdev '$file/fault' doesn't exist"
continue;
fi
set_led "$vdev_enc_sysfs_path/fault" $val
done <<< "$out"
if [ "$rc" == "0" ] ; then
return 0
else
# We didn't see a sysfs entry that we wanted to set
return 3
fi
}
if [ ! -z "$ZEVENT_VDEV_ENC_SYSFS_PATH" ] && [ ! -z "$ZEVENT_VDEV_STATE_STR" ] ; then
# Got a statechange for an individual VDEV
val=$(state_to_val "$ZEVENT_VDEV_STATE_STR")
vdev="$(basename $ZEVENT_VDEV_PATH)"
check_and_set_led "$ZEVENT_VDEV_ENC_SYSFS_PATH/fault" "$val"
else
# Process the entire pool
process_pool $(zed_guid_to_pool $ZEVENT_POOL_GUID)
fi