t/zbd: test that zone_reset_threshold calculation is correct

The option "zone_reset_threshold" specifies the ratio of logical blocks
with data to trigger zone resets. When the I/O range includes
conventional zones, only blocks in sequential zones must be used to
track this value. A recently fixed bug has uncovered that the number of
blocks in conventional zones were erroneously counted as the blocks
with data.

To prevent future regressions, add a test case to confirm that the
logical blocks accounting does not include conventional zones.

Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Signed-off-by: Dmitry Fomichev <dmitry.fomichev@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/t/zbd/test-zbd-support b/t/zbd/test-zbd-support
index 4ad553814db60f1a3b56d046a69c5c2b148b42c4..217fdd1048c164afa81a1b4758d5fe4eec1367bc 100755 (executable)
--- a/t/zbd/test-zbd-support
+++ b/t/zbd/test-zbd-support
@@ -1047,6 +1047,38 @@ test51() {
        run_fio "${opts[@]}" >> "${logfile}.${test_number}" 2>&1 || return $?
 }
 
+# Verify that zone_reset_threshold only takes logical blocks from seq
+# zones into account, and logical blocks of conv zones are not counted.
+test52() {
+       local off io_size
+
+       require_zbd || return $SKIP_TESTCASE
+       require_conv_zones 8 || return $SKIP_TESTCASE
+       require_seq_zones 8 || return $SKIP_TESTCASE
+
+       reset_zone "${dev}" -1
+
+       # Total I/O size is 1/8 = 0.125 of the I/O range of cont + seq zones.
+       # Set zone_reset_threshold as 0.1. The threshold size is less than
+       # 0.125, then, reset count zero is expected.
+       # On the other hand, half of the I/O range is covered by conv zones.
+       # If fio would count the conv zones for zone_reset_threshold, the ratio
+       # were more than 0.5 and would trigger zone resets.
+
+       off=$((first_sequential_zone_sector * 512 - 8 * zone_size))
+       io_size=$((zone_size * 16 / 8))
+       run_fio --name=job --filename=$dev --rw=randwrite --bs=$((zone_size/16))\
+               --size=$((zone_size * 16)) --softrandommap=1 \
+               --io_size=$((io_size)) "$(ioengine "psync")" --offset=$off \
+               --zonemode=zbd --direct=1 --zonesize=${zone_size} \
+               --zone_reset_threshold=.1 --zone_reset_frequency=1.0 \
+               ${job_var_opts[@]} --debug=zbd \
+               >> "${logfile}.${test_number}" 2>&1 || return $?
+
+       check_written ${io_size} || return $?
+       check_reset_count -eq 0 || return $?
+}
+
 tests=()
 dynamic_analyzer=()
 reset_all_zones=