On Fri, Sep 15, 2023 at 10:16:32AM +0100, Filipe Manana wrote: > On Fri, Sep 15, 2023 at 8:28 AM Naohiro Aota <naohiro.aota@xxxxxxx> wrote: > > > > Running btrfs/076 on a zoned null_blk device will fail with the following error. > > > > - output mismatch (see /host/results/btrfs/076.out.bad) > > --- tests/btrfs/076.out 2021-02-05 01:44:20.000000000 +0000 > > +++ /host/results/btrfs/076.out.bad 2023-09-15 01:49:36.000000000 +0000 > > @@ -1,3 +1,3 @@ > > QA output created by 076 > > -80 > > -80 > > +83 > > +83 > > ... > > > > This is because the default value of zone_append_max_bytes is 127.5 KB > > which is smaller than BTRFS_MAX_UNCOMPRESSED (128K). So, the extent size is > > limited to 126976 (= ROUND_DOWN(127.5K, 4096)), which makes the number of > > extents larger, and fails the test. > > > > Instead of hard-coding the number of extents, we can calculate it using the > > max extent size of an extent. It is limited by either > > BTRFS_MAX_UNCOMPRESSED or zone_append_max_bytes. > > > > Signed-off-by: Naohiro Aota <naohiro.aota@xxxxxxx> > > Looks good, > > Reviewed-by: Filipe Manana <fdmanana@xxxxxxxx> > > Just two minor comments below. > > > --- > > tests/btrfs/076 | 23 +++++++++++++++++++++-- > > tests/btrfs/076.out | 3 +-- > > 2 files changed, 22 insertions(+), 4 deletions(-) > > > > diff --git a/tests/btrfs/076 b/tests/btrfs/076 > > index 89e9672d09e2..a5cc3eb96b2f 100755 > > --- a/tests/btrfs/076 > > +++ b/tests/btrfs/076 > > @@ -28,13 +28,28 @@ _supported_fs btrfs > > _require_test > > _require_scratch > > > > +# An extent size can be up to BTRFS_MAX_UNCOMPRESSED > > +max_extent_size=$(( 128 << 10 )) > > For consistency with every other test and common files, using 128 * > 1024 would be perhaps better. I certainly find it easier to read, but > that's a personal preference only. > > > +if _scratch_btrfs_is_zoned; then > > + zone_append_max=$(cat "/sys/block/$(_short_dev $SCRATCH_DEV)/queue/zone_append_max_bytes") > > + if [[ $zone_append_max -gt 0 && $zone_append_max -lt $max_extent_size ]]; then > > + # Round down to PAGE_SIZE > > + max_extent_size=$(( $zone_append_max / 4096 * 4096 )) > > + fi > > +fi > > +file_size=$(( 10 << 20 )) > > And this one it's even less immediate to understand, having 1 * 1024 * > 1024 would make it much more easier to read. Agreed. I'll use 1024 and repost. Thanks.
