mdadm/tests/25raid456-reshape-while-recovery

devs="$dev0 $dev1 $dev2"

set_up_test()
{
	mdadm -Cv -R -n 3 -l5 $md0 $devs --assume-clean --size=10M || die "create array failed"
	mdadm -a $md0 $dev3 $dev4 || die "failed to bind new disk to array"
	echo 1000 > /sys/block/md0/md/sync_speed_max
}

clean_up_test()
{
	mdadm -S $md0
}

trap 'clean_up_test' EXIT

set_up_test || die "set up test failed"

# set up replacement
echo want_replacement > /sys/block/md0/md/rd0/state
sleep 2

# trigger reshape
echo frozen > /sys/block/md0/md/sync_action
mdadm --grow -l 6 $md0
sleep 2

# reassemeble array
mdadm -S $md0 || die "can't stop array"
mdadm --assemble $md0 $devs $dev3 $dev4 || die "can't assemble array"

exit 0