Re: [PATCH][v4] fstests: add generic/609 to test O_DIRECT|O_DSYNC

[Eryu Guan <guan@eryu.me>]

On Fri, Sep 04, 2020 at 02:12:35PM +0100, Filipe Manana wrote:
> On Wed, Sep 2, 2020 at 6:11 PM Josef Bacik <josef@toxicpanda.com> wrote:
> >
> > We had a problem recently where btrfs would deadlock with
> > O_DIRECT|O_DSYNC because of an unexpected dependency on ->fsync in
> > iomap.  This was only caught by chance with aiostress, because weirdly
> > we don't actually test this particular configuration anywhere in
> > xfstests.  Fix this by adding a basic test that just does
> > O_DIRECT|O_DSYNC writes.  With this test the box deadlocks right away
> > with Btrfs, which would have been helpful in finding this issue before
> > the patches were merged.
> >
> > Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
> > Signed-off-by: Josef Bacik <josef@toxicpanda.com>
> > ---
> > v3->v4:
> > - Trying to see how many times I can fuck this thing up.
> > - Simplified the xfs_io command per Darrick's suggestion.
> > - Added it to the rw group.
> >
> >  tests/generic/609     | 43 +++++++++++++++++++++++++++++++++++++++++++
> >  tests/generic/609.out |  3 +++
> >  tests/generic/group   |  1 +
> >  3 files changed, 47 insertions(+)
> >  create mode 100755 tests/generic/609
> >  create mode 100644 tests/generic/609.out
> >
> > diff --git a/tests/generic/609 b/tests/generic/609
> > new file mode 100755
> > index 00000000..6c74ae63
> > --- /dev/null
> > +++ b/tests/generic/609
> > @@ -0,0 +1,43 @@
> > +#! /bin/bash
> > +# SPDX-License-Identifier: GPL-2.0
> > +# Copyright (c) 2020 Josef Bacik.  All Rights Reserved.
> > +#
> > +# FS QA Test 609
> > +#
> > +# iomap can call generic_write_sync() if we're O_DSYNC, so write a basic test to
> > +# exercise O_DSYNC so any unsuspecting file systems will get lockdep warnings if
> > +# their locking isn't compatible.
> > +#
> > +seq=`basename $0`
> > +seqres=$RESULT_DIR/$seq
> > +echo "QA output created by $seq"
> > +
> > +here=`pwd`
> > +tmp=/tmp/$$
> > +status=1       # failure is the default!
> > +trap "_cleanup; exit \$status" 0 1 2 3 15
> > +
> > +_cleanup()
> > +{
> > +       cd /
> > +       rm -f $tmp.*
> > +       rm -rf $TEST_DIR/file
> > +}
> > +
> > +# get standard environment, filters and checks
> > +. ./common/rc
> > +. ./common/filter
> > +
> > +# remove previous $seqres.full before test
> > +rm -f $seqres.full
> > +
> > +# Modify as appropriate.
> > +_supported_fs generic
> > +_supported_os Linux
> > +_require_test
> > +_require_xfs_io_command "pwrite"
> 
> missing a:
> 
> _require_odirect
> 
> Other than that, it looks good. Perhaps Eryu can add that when picking
> this, so you avoid sending a v5.

Yeah, I've added that on commit.

> 
> Reviewed-by: Filipe Manana <fdmanana@suse.com>

Thanks for the review!

Eryu