On Fri, Jun 04, 2021 at 02:33:51PM +0900, Shin'ichiro Kawasaki wrote:
> The test case #31 in t/zbd/test-zbd-support writes 128KB data to
> sequential write required zones as the preparation for the following
> random read test. The data write leaves the target zones in open status.
> The test case refers the variable 'nz', which has max_open_zones value,
> to decide how many zones to write the data. However, the end condition
> of the write target zone loop has a bug. The disk end offset is used as
> the loop end condition, which does not match the last target zone when
> number of sequential write required zones divided by nz has remainder.
> This results in write to more zones than nz=max_open_zones limit and the
> test case failure. To fix the bug and to simplify the script, avoid the
> loop and utilize zonemode strided to achieve the same data write
> pattern. Also specify size and io_size using nz to reliably count the
> write target zones.
>
> Even with the fix above, still the number of open zones may exceed
> max_open_zones since other test cases executed before the test case 31
> may leave open zones on the test target device. To avoid this failure,
> reset all zones before the data write.
>
> The failures were observed with libzbc I/O engine after the commit
> e8267436fd7a ("engines/libzbc: add support for the get_max_open_zones io
> op"), which changed the max_open_zones value fio refers.
>
> Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@xxxxxxx>
> Reviewed-by: Damien Le Moal <damien.lemoal@xxxxxxx>
> ---
> t/zbd/test-zbd-support | 36 ++++++++++++++++--------------------
> 1 file changed, 16 insertions(+), 20 deletions(-)
>
> diff --git a/t/zbd/test-zbd-support b/t/zbd/test-zbd-support
> index 015fa1dc..a684f988 100755
> --- a/t/zbd/test-zbd-support
> +++ b/t/zbd/test-zbd-support
> @@ -731,32 +731,28 @@ test30() {
> test31() {
> local bs inc nz off opts size
>
> - prep_write
> - # Start with writing 128 KB to max_open_zones sequential zones.
> - bs=128K
> + [ -n "$is_zbd" ] && reset_zone "$dev" -1
> +
> + # As preparation, write 128 KB to sequential write required zones. Limit
> + # write target zones up to max_open_zones to keep test time reasonable.
> + # To distribute the write target zones evenly, skip certain zones for every
> + # write. Utilize zonemode strided for such write patterns.
> + bs=$((128 * 1024))
> nz=$((max_open_zones))
> if [[ $nz -eq 0 ]]; then
> nz=128
> fi
> - # shellcheck disable=SC2017
> - inc=$(((disk_size - (first_sequential_zone_sector * 512)) / (nz * zone_size)
> - * zone_size))
> - if [ "$inc" -eq 0 ]; then
> - require_seq_zones $nz || return $SKIP_TESTCASE
> - fi
> - opts=()
> - for ((off = first_sequential_zone_sector * 512; off < disk_size;
> - off += inc)); do
> - opts+=("--name=$dev" "--filename=$dev" "--offset=$off" "--io_size=$bs")
> - opts+=("--bs=$bs" "--size=$zone_size" "$(ioengine "libaio")")
> - opts+=("--rw=write" "--direct=1" "--thread=1" "--stats=0")
> - opts+=("--zonemode=zbd" "--zonesize=${zone_size}")
> - opts+=(${job_var_opts[@]})
> - done
> - "$(dirname "$0")/../../fio" "${opts[@]}" >> "${logfile}.${test_number}" 2>&1
> - # Next, run the test.
> off=$((first_sequential_zone_sector * 512))
> size=$((disk_size - off))
> + inc=$(((size / nz / zone_size) * zone_size))
> + opts=("--name=$dev" "--filename=$dev" "--rw=write" "--bs=${bs}")
> + opts+=("--offset=$off" "--size=$((inc * nz))" "--io_size=$((bs * nz))")
> + opts+=("--zonemode=strided" "--zonesize=${bs}" "--zonerange=${inc}")
> + opts+=("--direct=1")
> + echo "fio ${opts[@]}" >> "${logfile}.${test_number}"
> + "$(dirname "$0")/../../fio" "${opts[@]}" >> "${logfile}.${test_number}" 2>&1
> +
> + # Next, run the test.
> opts=("--name=$dev" "--filename=$dev" "--offset=$off" "--size=$size")
> opts+=("--bs=$bs" "$(ioengine "psync")" "--rw=randread" "--direct=1")
> opts+=("--thread=1" "--time_based" "--runtime=30" "--zonemode=zbd")
> --
> 2.31.1
>
Reviewed-by: Niklas Cassel <niklas.cassel@xxxxxxx>
