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

   1 #!/bin/sh
   2 #
   3 # Turn off/on the VDEV's enclosure fault LEDs when the pool's state changes.
   4 #
   5 # Turn the VDEV's fault LED on if it becomes FAULTED, DEGRADED or UNAVAIL.
   6 # Turn the LED off when it's back ONLINE again.
   7 #
   8 # This script run in two basic modes:
   9 #
  10 # 1. If $ZEVENT_VDEV_ENC_SYSFS_PATH and $ZEVENT_VDEV_STATE_STR are set, then
  11 # only set the LED for that particular VDEV. This is the case for statechange
  12 # events and some vdev_* events.
  13 #
  14 # 2. If those vars are not set, then check the state of all VDEVs in the pool
  15 # and set the LEDs accordingly.  This is the case for pool_import events.
  16 #
  17 # Note that this script requires that your enclosure be supported by the
  18 # Linux SCSI enclosure services (ses) driver.  The script will do nothing
  19 # if you have no enclosure, or if your enclosure isn't supported.
  20 #
  21 # Exit codes:
  22 #   0: enclosure led successfully set
  23 #   1: enclosure leds not not available
  24 #   2: enclosure leds administratively disabled
  25 #   3: The led sysfs path passed from ZFS does not exist
  26 #   4: $ZPOOL not set
  27 #   5: awk is not installed
  28
  29 [ -f "${ZED_ZEDLET_DIR}/zed.rc" ] && . "${ZED_ZEDLET_DIR}/zed.rc"
  30 . "${ZED_ZEDLET_DIR}/zed-functions.sh"
  31
  32 if [ ! -d /sys/class/enclosure ] ; then
  33         exit 1
  34 fi
  35
  36 if [ "${ZED_USE_ENCLOSURE_LEDS}" != "1" ] ; then
  37         exit 2
  38 fi
  39
  40 zed_check_cmd "$ZPOOL" || exit 4
  41 zed_check_cmd awk || exit 5
  42
  43 # Global used in set_led debug print
  44 vdev=""
  45
  46 # check_and_set_led (file, val)
  47 #
  48 # Read an enclosure sysfs file, and write it if it's not already set to 'val'
  49 #
  50 # Arguments
  51 #   file: sysfs file to set (like /sys/class/enclosure/0:0:1:0/SLOT 10/fault)
  52 #   val: value to set it to
  53 #
  54 # Return
  55 #  0 on success, 3 on missing sysfs path
  56 #
  57 check_and_set_led()
  58 {
  59         file="$1"
  60         val="$2"
  61
  62         if [ ! -e "$file" ] ; then
  63                 return 3
  64         fi
  65
  66         # If another process is accessing the LED when we attempt to update it,
  67         # the update will be lost so retry until the LED actually changes or we
  68         # timeout.
  69         for _ in $(seq 1 5); do
  70                 # We want to check the current state first, since writing to the
  71                 # 'fault' entry always always causes a SES command, even if the
  72                 # current state is already what you want.
  73                 current=$(cat "${file}")
  74
  75                 # On some enclosures if you write 1 to fault, and read it back,
  76                 # it will return 2.  Treat all non-zero values as 1 for
  77                 # simplicity.
  78                 if [ "$current" != "0" ] ; then
  79                         current=1
  80                 fi
  81
  82                 if [ "$current" != "$val" ] ; then
  83                         echo "$val" > "$file"
  84                         zed_log_msg "vdev $vdev set '$file' LED to $val"
  85                 else
  86                         break
  87                 fi
  88         done
  89 }
  90
  91 state_to_val()
  92 {
  93         state="$1"
  94         if [ "$state" = "FAULTED" ] || [ "$state" = "DEGRADED" ] || \
  95            [ "$state" = "UNAVAIL" ] ; then
  96                 echo 1
  97         elif [ "$state" = "ONLINE" ] ; then
  98                 echo 0
  99         fi
 100 }
 101
 102 # process_pool ([pool])
 103 #
 104 # Iterate through a pool (or pools) and set the VDEV's enclosure slot LEDs to
 105 # the VDEV's state.
 106 #
 107 # Arguments
 108 #   pool:       Optional pool name.  If not specified, iterate though all pools.
 109 #
 110 # Return
 111 #  0 on success, 3 on missing sysfs path
 112 #
 113 process_pool()
 114 {
 115         pool="$1"
 116         rc=0
 117
 118         # Lookup all the current LED values and paths in parallel
 119         #shellcheck disable=SC2016
 120         cmd='echo led_token=$(cat "$VDEV_ENC_SYSFS_PATH/fault"),"$VDEV_ENC_SYSFS_PATH",'
 121         out=$($ZPOOL status -vc "$cmd" "$pool" | grep 'led_token=')
 122
 123         #shellcheck disable=SC2034
 124         echo "$out" | while read -r vdev state read write chksum therest; do
 125                 # Read out current LED value and path
 126                 tmp=$(echo "$therest" | sed 's/^.*led_token=//g')
 127                 vdev_enc_sysfs_path=$(echo "$tmp" | awk -F ',' '{print $2}')
 128                 current_val=$(echo "$tmp" | awk -F ',' '{print $1}')
 129
 130                 if [ "$current_val" != "0" ] ; then
 131                         current_val=1
 132                 fi
 133
 134                 if [ -z "$vdev_enc_sysfs_path" ] ; then
 135                         # Skip anything with no sysfs LED entries
 136                         continue
 137                 fi
 138
 139                 if [ ! -e "$vdev_enc_sysfs_path/fault" ] ; then
 140                         #shellcheck disable=SC2030
 141                         rc=1
 142                         zed_log_msg "vdev $vdev '$file/fault' doesn't exist"
 143                         continue;
 144                 fi
 145
 146                 val=$(state_to_val "$state")
 147
 148                 if [ "$current_val" = "$val" ] ; then
 149                         # LED is already set correctly
 150                         continue;
 151                 fi
 152
 153                 if ! check_and_set_led "$vdev_enc_sysfs_path/fault" "$val"; then
 154                         rc=1
 155                 fi
 156
 157         done
 158
 159         #shellcheck disable=SC2031
 160         if [ "$rc" = "0" ] ; then
 161                 return 0
 162         else
 163                 # We didn't see a sysfs entry that we wanted to set
 164                 return 3
 165         fi
 166 }
 167
 168 if [ ! -z "$ZEVENT_VDEV_ENC_SYSFS_PATH" ] && [ ! -z "$ZEVENT_VDEV_STATE_STR" ] ; then
 169         # Got a statechange for an individual VDEV
 170         val=$(state_to_val "$ZEVENT_VDEV_STATE_STR")
 171         vdev=$(basename "$ZEVENT_VDEV_PATH")
 172         check_and_set_led "$ZEVENT_VDEV_ENC_SYSFS_PATH/fault" "$val"
 173 else
 174         # Process the entire pool
 175         poolname=$(zed_guid_to_pool "$ZEVENT_POOL_GUID")
 176         process_pool "$poolname"
 177 fi