Re: [PATCH 1/3] 285: Fix test for ext4 in some configurations

[Jan Kara <jack@suse.cz>]

On Fri 31-05-13 08:30:00, Dave Chinner wrote:
> On Thu, May 30, 2013 at 02:45:37PM +0200, Jan Kara wrote:
> > In some configurations (e.g. 1 KB block size), ext4 can decide it is
> > better to zero out several blocks rather than splitting unwritten
> > extent. This changes results SEEK_HOLE / SEEK_DATA returns and thus the
> > test fails. Fix the problem by disabling the feature for this test.
> > 
> > Signed-off-by: Jan Kara <jack@suse.cz>
> > ---
> >  tests/generic/285 | 6 ++++++
> >  1 file changed, 6 insertions(+)
> > 
> > diff --git a/tests/generic/285 b/tests/generic/285
> > index b700a15..8078b1c 100755
> > --- a/tests/generic/285
> > +++ b/tests/generic/285
> > @@ -46,6 +46,12 @@ BASE_TEST_FILE=$TEST_DIR/seek_sanity_testfile
> >  
> >  [ -x $here/src/seek_sanity_test ] || _notrun "seek_sanitfy_tester not built"
> >  
> > +# Disable extent zeroing for ext4 as that change where holes are created
> > +if [ "$FSTYP" = "ext4" ]; then
> > +	DEV=`basename $TEST_DEV`
> > +	echo 0 >/sys/fs/ext4/$DEV/extent_max_zeroout_kb
> > +fi
> 
> would that be better going into _require_seek_data_hole so that 286
> also picks up this behaviour for ext4?
  Actually, thinking about it, test 286 doesn't need extent_max_zeroout_kb
set. It just compares file sizes / used blocks are the same and they really
should be regardless of extent_max_zeroout_kb setting. It is even desirable
to test this with the default extent_max_zeroout_kb setting...

								Honza
-- 
Jan Kara <jack@suse.cz>
SUSE Labs, CR