Re: [RFC PATCH] generic: regression test for a FALLOC_FL_UNSHARE bug in XFS

[Zorro Lang <zlang@redhat.com>]

On Mon, Aug 23, 2021 at 05:38:35PM -0700, Darrick J. Wong wrote:
> From: Darrick J. Wong <djwong@kernel.org>
> 
> This is a regression test for "xfs: only set IOMAP_F_SHARED when
> providing a srcmap to a write".
> 
> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
> ---
>  tests/generic/729     |   73 +++++++++++++++++++++++++++++++++++++++++++++++++
>  tests/generic/729.out |    2 +
>  2 files changed, 75 insertions(+)
>  create mode 100755 tests/generic/729
>  create mode 100644 tests/generic/729.out
> 
> diff --git a/tests/generic/729 b/tests/generic/729
> new file mode 100755
> index 00000000..269aed65
> --- /dev/null
> +++ b/tests/generic/729
> @@ -0,0 +1,73 @@
> +#! /bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (c) 2021 Oracle.  All Rights Reserved.
> +#
> +# FS QA Test 729
> +#
> +# This is a regression test for "xfs: only set IOMAP_F_SHARED when providing a
> +# srcmap to a write".  If a user creates a sparse shared region in a file,
> +# convinces XFS to create a copy-on-write delayed allocation reservation
> +# spanning both the shared blocks and the holes, and then calls the fallocate
> +# unshare command to unshare the entire sparse region, XFS incorrectly tells
> +# iomap that the delalloc blocks for the holes are shared, which causes it to
> +# error out while trying to unshare a hole.
> +#
> +. ./common/preamble
> +_begin_fstest auto clone unshare
> +
> +# Override the default cleanup function.
> +_cleanup()
> +{
> +	cd /
> +	rm -r -f $tmp.* $TEST_DIR/$seq
> +}
> +
> +# Import common functions.
> +. ./common/reflink
> +. ./common/filter
> +
> +# real QA test starts here
> +
> +# Modify as appropriate.
> +_supported_fs generic
> +_require_cp_reflink
> +_require_test_reflink
> +_require_test_program "punch-alternating"
> +_require_xfs_io_command "fpunch"

I didn't find "fpunch" in this case, but find "cowextsize". Did I
miss something?

Others looks good to me.
Reviewed-by: Zorro Lang <zlang@redhat.com>

cc fstests@vger.kernel.org, due to it's a patch to xfstests.

Thanks,
Zorro

> +_require_xfs_io_command "funshare"
> +
> +mkdir $TEST_DIR/$seq
> +file1=$TEST_DIR/$seq/a
> +file2=$TEST_DIR/$seq/b
> +
> +$XFS_IO_PROG -f -c "pwrite -S 0x58 -b 10m 0 10m" $file1 >> $seqres.full
> +
> +f1sum0="$(md5sum $file1 | _filter_test_dir)"
> +
> +_cp_reflink $file1 $file2
> +$here/src/punch-alternating -o 1 $file2
> +
> +f2sum0="$(md5sum $file2 | _filter_test_dir)"
> +
> +# set cowextsize to the defaults (128k) to force delalloc cow preallocations
> +test "$FSTYP" = "xfs" && $XFS_IO_PROG -c 'cowextsize 0' $file2
> +$XFS_IO_PROG -c "funshare 0 10m" $file2
> +
> +f1sum1="$(md5sum $file1 | _filter_test_dir)"
> +f2sum1="$(md5sum $file2 | _filter_test_dir)"
> +
> +test "${f1sum0}" = "${f1sum1}" || echo "file1 should not have changed"
> +test "${f2sum0}" = "${f2sum1}" || echo "file2 should not have changed"
> +
> +_test_cycle_mount
> +
> +f1sum2="$(md5sum $file1 | _filter_test_dir)"
> +f2sum2="$(md5sum $file2 | _filter_test_dir)"
> +
> +test "${f1sum2}" = "${f1sum1}" || echo "file1 should not have changed ondisk"
> +test "${f2sum2}" = "${f2sum1}" || echo "file2 should not have changed ondisk"
> +
> +# success, all done
> +echo Silence is golden
> +status=0
> +exit
> diff --git a/tests/generic/729.out b/tests/generic/729.out
> new file mode 100644
> index 00000000..0f175ae2
> --- /dev/null
> +++ b/tests/generic/729.out
> @@ -0,0 +1,2 @@
> +QA output created by 729
> +Silence is golden
>