On Thu, Feb 20, 2020 at 2:39 PM Josef Bacik <josef@xxxxxxxxxxxxxx> wrote:
>
> This is a testcase for a corner that I missed when trying to fix gap
> extents for btrfs. We would end up with gaps if we hole punched past
> isize and then extended past the gap in a specific way. This is a
> simple reproducer to show the problem, and has been properly fixed by my
> patches now.
>
> Signed-off-by: Josef Bacik <josef@xxxxxxxxxxxxxx>
> ---
> tests/btrfs/204 | 85 +++++++++++++++++++++++++++++++++++++++++++++
> tests/btrfs/204.out | 5 +++
> tests/btrfs/group | 1 +
> 3 files changed, 91 insertions(+)
> create mode 100755 tests/btrfs/204
> create mode 100644 tests/btrfs/204.out
>
> diff --git a/tests/btrfs/204 b/tests/btrfs/204
> new file mode 100755
> index 00000000..0d5c4bed
> --- /dev/null
> +++ b/tests/btrfs/204
> @@ -0,0 +1,85 @@
> +#! /bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (c) 2020 Facebook. All Rights Reserved.
> +#
> +# FS QA Test 204
> +#
> +# Validate that without no-holes we do not get a i_size that is after a gap in
> +# the file extents on disk when punching a hole past i_size. This is fixed by
> +# the following patches
> +#
> +# btrfs: use the file extent tree infrastructure
> +# btrfs: replace all uses of btrfs_ordered_update_i_size
> +#
> +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
> +. ./common/dmlogwrites
> +
> +# 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_test
> +_require_scratch
> +_require_log_writes
_require_xfs_io_command "falloc" "-k"
_require_xfs_io_command "fpunch"
> +
> +_log_writes_init $SCRATCH_DEV
> +_log_writes_mkfs "-O ^no-holes" >> $seqres.full 2>&1
> +
> +# There's not a straightforward way to commit the transaction without also
> +# flushing dirty pages, so shorten the commit interval to 1 so we're sure to get
> +# a commit with our broken file
> +_log_writes_mount -o commit=1
> +
> +# This creates a gap extent because fpunch doesn't insert hole extents past
> +# i_size
> +xfs_io -f -c "falloc -k 4k 8k" $SCRATCH_MNT/file
> +xfs_io -f -c "fpunch 4k 4k" $SCRATCH_MNT/file
> +
> +# The pwrite extends the i_size to cover the gap extent, and then the truncate
> +# sets the disk_i_size to 12k because it assumes everything was a-ok.
> +xfs_io -f -c "pwrite 0 4k" $SCRATCH_MNT/file | _filter_xfs_io
> +xfs_io -f -c "pwrite 0 8k" $SCRATCH_MNT/file | _filter_xfs_io
> +xfs_io -f -c "truncate 12k" $SCRATCH_MNT/file
> +
> +# Wait for a transaction commit
> +sleep 2
> +
> +_log_writes_unmount
> +_log_writes_remove
> +
> +cur=$(_log_writes_find_next_fua 0)
> +echo "cur=$cur" >> $seqres.full
> +while [ ! -z "$cur" ]; do
> + _log_writes_replay_log_range $cur $SCRATCH_DEV >> $seqres.full
> +
> + # We only care about the fs consistency, so just run fsck, we don't have
> + # to mount the fs to validate it
> + _check_scratch_fs
> +
> + cur=$(_log_writes_find_next_fua $(($cur + 1)))
> +done
> +
> +# success, all done
> +status=0
> +exit
> diff --git a/tests/btrfs/204.out b/tests/btrfs/204.out
> new file mode 100644
> index 00000000..44c7c8ae
> --- /dev/null
> +++ b/tests/btrfs/204.out
> @@ -0,0 +1,5 @@
> +QA output created by 204
> +wrote 4096/4096 bytes at offset 0
> +XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
> +wrote 8192/8192 bytes at offset 0
> +XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
> diff --git a/tests/btrfs/group b/tests/btrfs/group
> index 6acc6426..7a840177 100644
> --- a/tests/btrfs/group
> +++ b/tests/btrfs/group
> @@ -206,3 +206,4 @@
> 201 auto quick punch log
> 202 auto quick subvol snapshot
> 203 auto quick send clone
> +204 auto quick log replay
"prealloc" and "punch" groups as well.
Since this just tests another variant of the same problem, maybe it
could be added to btrfs/172, since that test is very recent and you
authored it as well.
Anyway, I don't have a strong preference.
The test itself looks good to me, and with the _require_xfs_io_command
thing added and the groups (maybe Eryu can add these at commit time):
Reviewed-by: Filipe Manana <fdmanana@xxxxxxxx>
> --
> 2.24.1
>
--
Filipe David Manana,
“Whether you think you can, or you think you can't — you're right.”
