Re: [PATCH 1/3] generic/182: retain existing btrfs behavior when len == 0

["Darrick J. Wong" <darrick.wong@oracle.com>]

On Wed, Nov 23, 2016 at 06:33:23PM +0800, Eryu Guan wrote:
> On Tue, Nov 22, 2016 at 06:10:54PM -0800, Darrick J. Wong wrote:
> > Since btrfs doesn't interpret len=0 as "go to EOF", test for that instead.
> > 
> > Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> > ---
> >  tests/generic/182     |    3 ++-
> >  tests/generic/182.out |    2 --
> >  2 files changed, 2 insertions(+), 3 deletions(-)
> > 
> > 
> > diff --git a/tests/generic/182 b/tests/generic/182
> > index f484399..dacb989 100755
> > --- a/tests/generic/182
> > +++ b/tests/generic/182
> > @@ -1,7 +1,8 @@
> >  #! /bin/bash
> >  # FS QA Test No. 182
> >  #
> > -# Test the convention that dedupe with length == 0 means "to the end of fileA"
> > +# Test the convention that dedupe with length == 0 doesn't mean "to the end of
> > +# fileA"
> 
> If I read the xfs patch and btrfs RFC patch thread correctly, 0 length
> means do nothing, right? Should we make it more clear and specific in
> the comments instead of "doesn't mean..."? I think that helps people
> understand the test.

Yeah, this is confusing and contradictory; I'll fix it.

--D

> 
> >  #   - Create a file.
> >  #   - Try to dedupe "zero" bytes (which means dedupe to EOF).
> >  #   - Check that the dedupe happened.
> 
> These comments need fixes too.
> 
> Thanks,
> Eryu
> 
> > diff --git a/tests/generic/182.out b/tests/generic/182.out
> > index 049a3ee..9841b76 100644
> > --- a/tests/generic/182.out
> > +++ b/tests/generic/182.out
> > @@ -1,12 +1,10 @@
> >  QA output created by 182
> >  Create the original files
> > -dedupe: Extents did not match.
> >  f4820540fc0ac02750739896fe028d56  TEST_DIR/test-182/file1
> >  69ad53078a16243d98e21d9f8704a071  TEST_DIR/test-182/file2
> >  69ad53078a16243d98e21d9f8704a071  TEST_DIR/test-182/file2.chk
> >  Compare against check files
> >  Make the original file almost dedup-able
> > -dedupe: Extents did not match.
> >  f4820540fc0ac02750739896fe028d56  TEST_DIR/test-182/file1
> >  158d4e3578b94b89cbb44493a2110fb9  TEST_DIR/test-182/file2
> >  158d4e3578b94b89cbb44493a2110fb9  TEST_DIR/test-182/file2.chk
> >