get_enclosure_slot

#!/usr/bin/bash

# Usage: get_enclosure_slot <sysfs sd*>|<sg_ses SCSI_IDENT_PORT_NAA_REG>

# "sysfs" or "sg_ses".
method=${1}

if [[ "$method" = "sysfs" ]]
then
        drive="${2/[0-9]*/}"
        # Globs not supported in [[ ]]
        [ -L /sys/block/$drive/device/enclosure_device* ] || exit 1
        slot_name=$(ls -d /sys/block/$drive/device/enclosure_device* | cut -d: -f 2)
        enclosure_id=$(readlink /sys/block/$drive/device/enclosure_device* | sed -e 's|.*/\(.*\)/.*$|\1|')
        # Replacing spaces with underscores since udev's $result / %c / %c{N+} can't handle spaces, despite docs.
        enclosure_model=$(cat "/sys/class/enclosure/$enclosure_id/device/model" | tr ' ' _)
        slot_num=$(cat "/sys/class/enclosure/$enclosure_id/$slot_name/slot")
        # Padding slot number with zeros makes for easier command line globbing when using the links.
        echo "enc-$enclosure_model-$enclosure_id-slot$(printf %03d $slot_num)"
        exit 0
elif [[ "$method" = "sg_ses" ]]
then
        port_naa=${2}
        mkdir -p /var/run/get_enclosure_slot || exit 1
        for enclosure in /sys/class/enclosure/*
        do
                enclosure_id=$(basename $enclosure)
                enclosure_sg="/dev/bsg/$enclosure_id"
                [[ -c $enclosure_sg ]] || continue
                [[ -f $enclosure/device/model ]] || continue
                # Replacing spaces with underscores since udev's $result / %c / %c{N+} can't handle spaces, despite docs.
                enclosure_model=$(tr ' ' _ < $enclosure/device/model)
                enclosure_slot=$(flock /var/run/get_enclosure_slot/$enclosure_id.lock sg_ses -q -A $port_naa -G dsn $enclosure_sg 2>/dev/null) || continue
                # Padding slot number with zeros makes for easier command line globbing when using the links.
                echo "enc-$enclosure_model-$enclosure_id-slot$(printf %03d $enclosure_slot)"
                exit 0
        done
        # Drive not found in any enclosure.
        exit 1
fi

# Invalid method specified.
exit 1