t/zbd: prevent test #31 from looping

The test 31 starts i/o to 128 zones in parallel.
There are two corner cases that are not properly handled in the
existing implementation -
1) If the total number of zones on the device is < 128, the test
will loop indefinitely because the loop increment is calculated as
zero by the script.
2) If the number of max_open_zones of the device is < 128, the
test will fail due to exceeding max_open_zones limit as the code
expects it to be >= 128.

Limit the number of open zones to the reported maximum
and skip the test if there is not enough zones on the device.

Signed-off-by: Dmitry Fomichev <dmitry.fomichev@wdc.com>
Reviewed-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@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 93456ec63e1b59bce6c2a0d613ab43910da0897a..033c2ebcf4a7de3728aa22a5dfc1a3a3fa23272f 100755 (executable)
--- a/t/zbd/test-zbd-support
+++ b/t/zbd/test-zbd-support
@@ -718,12 +718,18 @@ test31() {
     local bs inc nz off opts size
 
     prep_write
-    # Start with writing 128 KB to 128 sequential zones.
+    # Start with writing 128 KB to max_open_zones sequential zones.
     bs=128K
-    nz=128
+    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