Re: [PATCH v5] test unaligned punch hole at ENOSPC

[Anand Jain <anand.jain@xxxxxxxxxx>]

On 09/30/2018 12:40 AM, Filipe Manana wrote:
> On Sat, Sep 29, 2018 at 1:52 AM Anand Jain <anand.jain@xxxxxxxxxx> wrote:
> > Try to punch hole with unaligned size and offset when the FS is
> > full. Mainly holes are punched at locations which are unaligned
> > with the file extent boundaries when the FS is full by data.
> > As the punching holes at unaligned location will involve
> > truncating blocks instead of just dropping the extents, it shall
> > involve reserving data and metadata space for delalloc and data
> > alloc fails as the FS is full.
> >
> > btrfs_punch_hole()
> >   btrfs_truncate_block()
> >     btrfs_check_data_free_space() <-- ENOSPC
> >
> > We don't fail punch hole if the holes are aligned with the file
> > extent boundaries as it shall involve just dropping the related
> > extents.
> >
> > Signed-off-by: Anand Jain <anand.jain@xxxxxxxxxx>
> > ---
> > v4->v5:
> >   Update the change log
> >   Drop the directio option for xfs_io
>
> Except for the direct IO and change log, all my previous comments and
> questions weren't addressed/ answered.
> Thanks.

Ah. Now I notice there were two emails, I completely missed the other 
email. Will review. Thanks for pointing out.

Thanks, Anand


> > v3->v4:
> >   Add to the group punch
> > v2->v3:
> >   Add _require_xfs_io_command "fpunch"
> >   Add more logs to $seqfull.full
> >     mount options and
> >     group profile info
> >   Add sync after dd upto ENOSPC
> >   Drop fallocate -p and use xfs_io punch to create holes
> >   Use a testfile instead of filler file so that easy to trace
> > v1->v2: Use at least 256MB to test.
> > This test case fails on btrfs as of now.
> >   tests/btrfs/172     | 74 +++++++++++++++++++++++++++++++++++++++++++++++++++++
> >   tests/btrfs/172.out |  2 ++
> >   tests/btrfs/group   |  1 +
> >   3 files changed, 77 insertions(+)
> >   create mode 100755 tests/btrfs/172
> >   create mode 100644 tests/btrfs/172.out
> >
> > diff --git a/tests/btrfs/172 b/tests/btrfs/172
> > new file mode 100755
> > index 000000000000..1ecf01d862a2
> > --- /dev/null
> > +++ b/tests/btrfs/172
> > @@ -0,0 +1,74 @@
> > +#! /bin/bash
> > +# SPDX-License-Identifier: GPL-2.0
> > +# Copyright (c) 2018 Oracle. All Rights Reserved.
> > +#
> > +# FS QA Test 172
> > +#
> > +# Test if the unaligned (by size and offset) punch hole is successful when FS
> > +# is at ENOSPC.
> > +#
> > +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.*
> > +}
> > +
> > +# get standard environment, filters and checks
> > +. ./common/rc
> > +. ./common/filter
> > +
> > +# remove previous $seqres.full before test
> > +rm -f $seqres.full
> > +
> > +# real QA test starts here
> > +
> > +# Modify as appropriate.
> > +_supported_fs btrfs
> > +_supported_os Linux
> > +_require_scratch
> > +_require_xfs_io_command "fpunch"
> > +
> > +_scratch_mkfs_sized $((256 * 1024 *1024)) >> $seqres.full
> > +
> > +# max_inline helps to create regular extent
> > +_scratch_mount "-o max_inline=0,nodatacow"
> > +
> > +cat /proc/self/mounts | grep $SCRATCH_DEV >> $seqres.full
> > +$BTRFS_UTIL_PROG filesystem df $SCRATCH_MNT >> $seqres.full
> > +
> > +extent_size=$(_scratch_btrfs_sectorsize)
> > +unalign_by=512
> > +echo extent_size=$extent_size unalign_by=$unalign_by >> $seqres.full
> > +
> > +$XFS_IO_PROG -f -c "pwrite -S 0xab 0 $((extent_size * 10))" \
> > +                                       $SCRATCH_MNT/testfile >> $seqres.full
> > +
> > +echo "Fill fs upto ENOSPC" >> $seqres.full
> > +dd status=none if=/dev/zero of=$SCRATCH_MNT/filler bs=512 >> $seqres.full 2>&1
> > +sync
> > +
> > +hole_offset=0
> > +hole_len=$unalign_by
> > +$XFS_IO_PROG -f -c "fpunch $hole_offset $hole_len" $SCRATCH_MNT/testfile
> > +
> > +hole_offset=$(($extent_size + $unalign_by))
> > +hole_len=$(($extent_size - $unalign_by))
> > +$XFS_IO_PROG -f -c "fpunch $hole_offset $hole_len" $SCRATCH_MNT/testfile
> > +
> > +hole_offset=$(($extent_size * 2 + $unalign_by))
> > +hole_len=$(($extent_size * 5))
> > +$XFS_IO_PROG -f -c "fpunch $hole_offset $hole_len" $SCRATCH_MNT/testfile
> > +
> > +# success, all done
> > +echo "Silence is golden"
> > +status=0
> > +exit
> > diff --git a/tests/btrfs/172.out b/tests/btrfs/172.out
> > new file mode 100644
> > index 000000000000..ce2de3f0d107
> > --- /dev/null
> > +++ b/tests/btrfs/172.out
> > @@ -0,0 +1,2 @@
> > +QA output created by 172
> > +Silence is golden
> > diff --git a/tests/btrfs/group b/tests/btrfs/group
> > index feffc45b6564..45782565c3b7 100644
> > --- a/tests/btrfs/group
> > +++ b/tests/btrfs/group
> > @@ -174,3 +174,4 @@
> >   169 auto quick send
> >   170 auto quick snapshot
> >   171 auto quick qgroup
> > +172 auto quick punch
> > --
> > 1.8.3.1