On Tue, Oct 8, 2024 at 12:26 PM Mark Harmstone <maharmstone@xxxxxx> wrote:
>
> Adds a test for a bug we encountered on Linux 6.4 on aarch64, where a
> race could mean that csums weren't getting written to the log tree,
> leading to corruption when it was replayed.
>
> The patches to detect log this tree corruption are in btrfs-progs 6.11.
>
> Signed-off-by: Mark Harmstone <maharmstone@xxxxxx>
> ---
> common/dmlogwrites | 24 ++++++++++++++++++
> tests/btrfs/192 | 26 +-------------------
> tests/btrfs/333 | 59 +++++++++++++++++++++++++++++++++++++++++++++
> tests/btrfs/333.out | 2 ++
> 4 files changed, 86 insertions(+), 25 deletions(-)
> create mode 100755 tests/btrfs/333
> create mode 100644 tests/btrfs/333.out
>
> diff --git a/common/dmlogwrites b/common/dmlogwrites
> index c1c85de9..f7faf244 100644
> --- a/common/dmlogwrites
> +++ b/common/dmlogwrites
> @@ -203,3 +203,27 @@ _log_writes_replay_log_range()
> >> $seqres.full 2>&1
> [ $? -ne 0 ] && _fail "replay failed"
> }
> +
> +# Replay and check each fua/flush (specified by $2) point.
> +#
> +# Since dm-log-writes records bio sequentially, even just replaying a range
> +# still needs to iterate all records before the end point.
> +# When number of records grows, it will be unacceptably slow, thus we need
> +# to use relay-log itself to trigger fsck, avoid unnecessary seek.
> +_log_writes_fast_replay_check()
> +{
> + local check_point=$1
> + local blkdev=$2
> + local fsck_command=$3
> + local ret
> +
> + [ -z "$check_point" -o -z "$blkdev" ] && _fail \
> + "check_point and blkdev must be specified for log_writes_fast_replay_check"
> +
> + $here/src/log-writes/replay-log --log $LOGWRITES_DEV \
> + --replay $blkdev --check $check_point --fsck "$fsck_command" \
> + &> $tmp.full_fsck
> + ret=$?
> + tail -n 150 $tmp.full_fsck >> $seqres.full
> + [ $ret -ne 0 ] && _fail "fsck failed during replay"
> +}
> diff --git a/tests/btrfs/192 b/tests/btrfs/192
> index f7fb65b8..449f0459 100755
> --- a/tests/btrfs/192
> +++ b/tests/btrfs/192
> @@ -96,30 +96,6 @@ delete_workload()
> done
> }
>
> -# Replay and check each fua/flush (specified by $2) point.
> -#
> -# Since dm-log-writes records bio sequentially, even just replaying a range
> -# still needs to iterate all records before the end point.
> -# When number of records grows, it will be unacceptably slow, thus we need
> -# to use relay-log itself to trigger fsck, avoid unnecessary seek.
> -log_writes_fast_replay_check()
> -{
> - local check_point=$1
> - local blkdev=$2
> - local fsck_command="$BTRFS_UTIL_PROG check $blkdev"
> - local ret
> -
> - [ -z "$check_point" -o -z "$blkdev" ] && _fail \
> - "check_point and blkdev must be specified for log_writes_fast_replay_check"
> -
> - $here/src/log-writes/replay-log --log $LOGWRITES_DEV \
> - --replay $blkdev --check $check_point --fsck "$fsck_command" \
> - &> $tmp.full_fsck
> - ret=$?
> - tail -n 150 $tmp.full_fsck >> $seqres.full
> - [ $ret -ne 0 ] && _fail "fsck failed during replay"
> -}
> -
> xattr_value=$(printf '%0.sX' $(seq 1 3800))
>
> # Bumping tree height to level 2.
> @@ -145,7 +121,7 @@ wait
> _log_writes_unmount
> _log_writes_remove
>
> -log_writes_fast_replay_check fua "$SCRATCH_DEV"
> +_log_writes_fast_replay_check fua "$SCRATCH_DEV" "$BTRFS_UTIL_PROG check $SCRATCH_DEV"
>
> echo "Silence is golden"
>
> diff --git a/tests/btrfs/333 b/tests/btrfs/333
> new file mode 100755
> index 00000000..13f113ca
> --- /dev/null
> +++ b/tests/btrfs/333
> @@ -0,0 +1,59 @@
> +#! /bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +#
> +# FS QA Test 333
> +#
> +# Test async dio with fsync to test a bug where a race meant that csums weren't
> +# getting written to the log tree, causing corruptions on remount. This can be
> +# seen on subpage FSes on 6.4.
> +#
> +. ./common/preamble
> +_begin_fstest auto quick metadata log volume
Why the volume group? The test isn't doing any volume management stuff.
However it should be in the "recoveryloop" group.
> +
> +_fixed_by_kernel_commit e917ff56c8e7 \
> + "btrfs: determine synchronous writers from bio or writeback control"
> +
> +fio_config=$tmp.fio
> +
> +. ./common/dmlogwrites
> +
> +_require_scratch
> +_require_log_writes
> +
> +cat >$fio_config <<EOF
> +[global]
> +iodepth=128
> +direct=1
> +ioengine=libaio
> +rw=randwrite
> +runtime=1s
> +[job0]
> +rw=randwrite
> +filename=$SCRATCH_MNT/file
> +size=1g
> +fdatasync=1
> +EOF
> +
> +_require_fio $fio_config
> +
> +cat $fio_config >> $seqres.full
> +
> +_log_writes_init $SCRATCH_DEV
> +_log_writes_mkfs >> $seqres.full 2>&1
> +_log_writes_mark mkfs
> +
> +_log_writes_mount
> +
> +$FIO_PROG $fio_config > /dev/null 2>&1
> +_log_writes_unmount
> +
> +_log_writes_remove
> +_log_writes_replay_log mkfs $SCRATCH_DEV
> +
> +_log_writes_fast_replay_check fua "$SCRATCH_DEV" "$BTRFS_UTIL_PROG check $SCRATCH_DEV"
Why do we need to do the replays twice? Once with
_log_writes_replay_log mkfs and then again with
_log_writes_fast_replay_check fua.
There's also nothing in this test that is btrfs specific, it could be
made a generic test instead.
Thanks.
> +
> +echo "Silence is golden"
> +
> +# success, all done
> +status=0
> +exit
> diff --git a/tests/btrfs/333.out b/tests/btrfs/333.out
> new file mode 100644
> index 00000000..60a15898
> --- /dev/null
> +++ b/tests/btrfs/333.out
> @@ -0,0 +1,2 @@
> +QA output created by 333
> +Silence is golden
> --
> 2.44.2
>
>
