On Wed, May 8, 2019 at 3:04 PM Qu Wenruo <wqu@xxxxxxxx> wrote:
>
> This test will test if we can still do the following operations when a
> full is full:
> - buffered write into unpopulated preallocated extent
> - clone the untouched preallocated extent
> - fsync
> - no data loss if power loss happens after above fsync
> Above operations should not fail, as they takes no extra data space.
>
> Xfs passes the test, while btrfs fails at fsync and has data loss.
> The fix for btrfs is:
> "btrfs: Flush before reflinking any extent to prevent NOCOW write falling
> back to CoW without data reservation"
>
> Signed-off-by: Qu Wenruo <wqu@xxxxxxxx>
Reviewed-by: Filipe Manana <fdmanana@xxxxxxxx>
Looks good now, thanks.
> ---
> changelog:
> v2:
> - Change the comment and commit message to make it describe the test
> itself, not the btrfs specific part.
> - Use $XFS_IO_PROG to replace xfs_io.
> v3:
> - Move the current test result and btrfs fix to commit message
> - Also test if data is consistent after power loss and log recovery
> v4:
> - Skip the checksum of padding file
> - Use golden output to verify the checksum
> - Rename "checkpoint" to "checksum"
> - Add _require_metadata_journaling check
> ---
> tests/generic/545 | 83 +++++++++++++++++++++++++++++++++++++++++++
> tests/generic/545.out | 3 ++
> tests/generic/group | 1 +
> 3 files changed, 87 insertions(+)
> create mode 100755 tests/generic/545
> create mode 100644 tests/generic/545.out
>
> diff --git a/tests/generic/545 b/tests/generic/545
> new file mode 100755
> index 00000000..eb63022d
> --- /dev/null
> +++ b/tests/generic/545
> @@ -0,0 +1,83 @@
> +#! /bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (C) 2019 SUSE Linux Products GmbH. All Rights Reserved.
> +#
> +# FS QA Test 545
> +#
> +# Test when a fs is full we can still:
> +# - Do buffered write into a unpopulated preallocated extent
> +# - Clone the untouched part of that preallocated extent
> +# - Fsync
> +# - No data loss even power loss happens after fsync
> +# All operations above should not fail.
> +#
> +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()
> +{
> + _cleanup_flakey
> + cd /
> + rm -f $tmp.*
> +}
> +
> +# get standard environment, filters and checks
> +. ./common/rc
> +. ./common/filter
> +. ./common/reflink
> +. ./common/dmflakey
> +
> +# remove previous $seqres.full before test
> +rm -f $seqres.full
> +
> +# real QA test starts here
> +
> +# Modify as appropriate.
> +_supported_fs generic
> +_supported_os Linux
> +_require_scratch_reflink
> +_require_dm_target flakey
> +
> +_scratch_mkfs_sized $((512 * 1024 * 1024)) >> $seqres.full 2>&1
> +_require_metadata_journaling $SCRATCH_DEV
> +_init_flakey
> +_mount_flakey
> +
> +# Create preallocated extent where we can write into
> +$XFS_IO_PROG -f -c 'falloc 8k 64m' "$SCRATCH_MNT/foobar" >> $seqres.full
> +
> +# Use up all data space, to test later write-into-preallocate behavior
> +_pwrite_byte 0x00 0 512m "$SCRATCH_MNT/padding" >> $seqres.full 2>&1
> +
> +# Sync to ensure that padding file reach disk so that at log recovery we
> +# still have no data space
> +sync
> +
> +# This should not fail
> +_pwrite_byte 0xcd 1m 16m "$SCRATCH_MNT/foobar" >> $seqres.full
> +
> +# Do reflink here, we shouldn't use extra data space, thus it should not fail
> +$XFS_IO_PROG -c "reflink ${SCRATCH_MNT}/foobar 8k 0 4k" "$SCRATCH_MNT/foobar" \
> + >> $seqres.full
> +
> +# Checksum before power loss
> +echo md5 before $(_md5_checksum "$SCRATCH_MNT/foobar")
> +
> +# Fsync to check if writeback is ok
> +$XFS_IO_PROG -c 'fsync' "$SCRATCH_MNT/foobar"
> +
> +# Now emulate power loss
> +_flakey_drop_and_remount
> +
> +# Checksum after power loss
> +echo md5 after $(_md5_checksum "$SCRATCH_MNT/foobar")
> +
> +# success, all done
> +status=0
> +exit
> diff --git a/tests/generic/545.out b/tests/generic/545.out
> new file mode 100644
> index 00000000..d38ac2e0
> --- /dev/null
> +++ b/tests/generic/545.out
> @@ -0,0 +1,3 @@
> +QA output created by 545
> +md5 before cdccc121ae95c72fdbe53d8e343ef5ee
> +md5 after cdccc121ae95c72fdbe53d8e343ef5ee
> diff --git a/tests/generic/group b/tests/generic/group
> index 40deb4d0..84892a60 100644
> --- a/tests/generic/group
> +++ b/tests/generic/group
> @@ -547,3 +547,4 @@
> 542 auto quick clone
> 543 auto quick clone
> 544 auto quick clone
> +545 auto quick clone enospc log
> --
> 2.21.0
>
--
Filipe David Manana,
“Whether you think you can, or you think you can't — you're right.”
