number_of_disks=5
chunksize_in_kib=512
chunksize_in_b=$[chunksize_in_kib*1024]
array_data_size_in_kib=$[chunksize_in_kib*(number_of_disks-2)*number_of_disks]
array_data_size_in_b=$[array_data_size_in_kib*1024]
devs="$dev0 $dev1 $dev2 $dev3 $dev4"

# default 2048 sectors
data_offset_in_kib=$[2048/2]

# make a raid5 from a file
dd if=/dev/urandom of=/tmp/RandFile bs=1024 count=$array_data_size_in_kib

# perform test for every layout
layouts="ls rs la ra parity-first ddf-zero-restart ddf-N-restart ddf-N-continue \
	left-asymmetric-6 right-asymmetric-6 left-symmetric-6 \
	right-symmetric-6 parity-first-6"

for layout in $layouts
do
    mdadm -CR $md0 -l6 --layout=$layout -n$number_of_disks -c $chunksize_in_kib $devs
    dd if=/tmp/RandFile of=$md0 bs=1024 count=$array_data_size_in_kib
    blockdev --flushbufs $md0; sync
    check wait
    blockdev --flushbufs $devs; sync
    echo 3 > /proc/sys/vm/drop_caches
    cmp -s -n $array_data_size_in_b $md0 /tmp/RandFile || { echo sanity cmp failed ; exit 2; }

    # wipe out 5 chunks on each device
    dd if=/dev/urandom of=$dev0 bs=1024 count=$[5*chunksize_in_kib] seek=$[data_offset_in_kib+chunksize_in_kib*0]
    dd if=/dev/urandom of=$dev1 bs=1024 count=$[5*chunksize_in_kib] seek=$[data_offset_in_kib+chunksize_in_kib*5]
    dd if=/dev/urandom of=$dev2 bs=1024 count=$[5*chunksize_in_kib] seek=$[data_offset_in_kib+chunksize_in_kib*10]
    dd if=/dev/urandom of=$dev3 bs=1024 count=$[5*chunksize_in_kib] seek=$[data_offset_in_kib+chunksize_in_kib*15]
    dd if=/dev/urandom of=$dev4 bs=1024 count=$[5*chunksize_in_kib] seek=$[data_offset_in_kib+chunksize_in_kib*20]

    blockdev --flushbufs $devs; sync
    echo 3 > /proc/sys/vm/drop_caches

    $dir/raid6check $md0 0 0 2>&1 | grep -qs "Error" || { echo should detect errors; exit 2; }

    $dir/raid6check $md0 0 0 autorepair > /dev/null || { echo repair failed; exit 2; }
    blockdev --flushbufs $md0 $devs; sync
    echo 3 > /proc/sys/vm/drop_caches

    $dir/raid6check $md0 0 0 2>&1 | grep -qs "Error" && { echo errors detected; exit 2; }
    cmp -s -n $array_data_size_in_b $md0 /tmp/RandFile || { echo cmp failed ; exit 2; }

    mdadm -S $md0
done