nullblk-zoned.sh

#!/bin/bash

if [ $# != 7 ]; then
        echo "Usage: $0 <sect size (B)> <zone size (MB)> <zone capacity (MB)> <max open zones> <max active zones> <nr conv zones> <nr seq zones>"
        exit 1
fi

scriptdir=$(cd $(dirname "$0") && pwd)

modprobe null_blk nr_devices=0 || return $?

function create_zoned_nullb()
{
        local nid=0
        local bs=$1
        local zs=$2
	local zc=$3
	local max_open_zones=$4
	local max_active_zones=$5
        local nr_conv=$6
        local nr_seq=$7

        cap=$(( zs * (nr_conv + nr_seq) ))

        while [ 1 ]; do
                if [ ! -b "/dev/nullb$nid" ]; then
                        break
                fi
                nid=$(( nid + 1 ))
        done

        dev="/sys/kernel/config/nullb/nullb$nid"
        mkdir "$dev"

        echo $bs > "$dev"/blocksize
        echo 0 > "$dev"/completion_nsec
        echo 0 > "$dev"/irqmode
        echo 2 > "$dev"/queue_mode
        echo 1024 > "$dev"/hw_queue_depth
        echo 1 > "$dev"/memory_backed
        echo 1 > "$dev"/zoned

        echo $cap > "$dev"/size
        echo $zs > "$dev"/zone_size
	echo $zc > "$dev"/zone_capacity
	echo $max_open_zones > "$dev"/zone_max_open
	echo $max_active_zones > "$dev"/zone_max_active
        echo $nr_conv > "$dev"/zone_nr_conv

        echo 1 > "$dev"/power

        echo mq-deadline > /sys/block/nullb$nid/queue/scheduler

        echo "$nid"
}

nulldev=$(create_zoned_nullb $1 $2 $3 $4 $5 $6 $7)
echo "Created /dev/nullb$nulldev"