On Fri, 21 Mar 2025 at 12:10, <fdmanana@xxxxxxxxxx> wrote:
>
> From: Filipe Manana <fdmanana@xxxxxxxx>
>
> Test that if we fsync a file that has no more hard links, power fail and
> then mount the filesystem, after the journal/log is replayed, the file
> doesn't exists anymore.
>
> This exercises a bug recently found and fixed by the following patch for
> the linux kernel:
>
> btrfs: fix fsync of files with no hard links not persisting deletion
>
> Signed-off-by: Filipe Manana <fdmanana@xxxxxxxx>
> ---
> tests/generic/764 | 78 +++++++++++++++++++++++++++++++++++++++++++
> tests/generic/764.out | 2 ++
> 2 files changed, 80 insertions(+)
> create mode 100755 tests/generic/764
> create mode 100644 tests/generic/764.out
>
> diff --git a/tests/generic/764 b/tests/generic/764
> new file mode 100755
> index 00000000..57d21095
> --- /dev/null
> +++ b/tests/generic/764
> @@ -0,0 +1,78 @@
> +#! /bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (c) 2025 SUSE Linux Products GmbH. All Rights Reserved.
> +#
> +# FS QA Test 764
> +#
> +# Test that if we fsync a file that has no more hard links, power fail and then
> +# mount the filesystem, after the journal/log is replayed, the file doesn't
> +# exists anymore.
> +#
> +. ./common/preamble
> +_begin_fstest auto quick log
> +
> +_cleanup()
> +{
> + if [ ! -z $XFS_IO_PID ]; then
> + kill $XFS_IO_PID > /dev/null 2>&1
> + wait $XFS_IO_PID > /dev/null 2>&1
> + fi
> + _cleanup_flakey
> + cd /
> + rm -r -f $tmp.*
> +}
> +
> +. ./common/dmflakey
> +
> +[ "$FSTYP" = "btrfs" ] && _fixed_by_kernel_commit xxxxxxxxxxxx \
> + "btrfs: fix fsync of files with no hard links not persisting deletion"
> +
> +_require_scratch
> +_require_dm_target flakey
> +_require_mknod
> +
> +_scratch_mkfs >>$seqres.full 2>&1 || _fail "mkfs failed"
> +_require_metadata_journaling $SCRATCH_DEV
> +_init_flakey
> +_mount_flakey
> +
> +touch $SCRATCH_MNT/foo
> +
> +# Commit the current transaction and persist the file.
> +_scratch_sync
> +
> +# A fifo to communicate with a background xfs_io process that will fsync the
> +# file after we deleted its hard link while it's open by xfs_io.
> +mkfifo $SCRATCH_MNT/fifo
After creating the pipe you can "exec 3<>$SCRATCH_MNT/fifo" (and
eventually unlink) ...
> +
> +tail -f $SCRATCH_MNT/fifo | $XFS_IO_PROG $SCRATCH_MNT/foo >>$seqres.full &
... and then simply "$XFS_IO_PROG $SCRATCH_MNT/foo <&3 >>$seqres.full &"
> +XFS_IO_PID=$!
> +
> +# Give some time for the xfs_io process to open a file descriptor for the file.
> +sleep 1
> +
> +# Now while the file is open by the xfs_io process, delete its only hard link.
> +rm -f $SCRATCH_MNT/foo
> +
> +# Now that it has no more hard links, make the xfs_io process fsync it.
> +echo "fsync" > $SCRATCH_MNT/fifo
No need for the quotes. But won't hurt either if that's more readable for you.
Moreover with the above you can also "echo fsync >&3".
> +
> +# Terminate the xfs_io process so that we can unmount.
> +echo "quit" > $SCRATCH_MNT/fifo
...
> +wait $XFS_IO_PID
> +unset XFS_IO_PID
> +
> +# Simulate a power failure and then mount again the filesystem to replay the
> +# journal/log.
> +_flakey_drop_and_remount
> +
> +# We don't expect the file to exist anymore, since it was fsynced when it had no
> +# more hard links.
> +[ -f $SCRATCH_MNT/foo ] && echo "file foo still exists"
> +
> +_unmount_flakey
> +
> +# success, all done
> +echo "Silence is golden"
> +status=0
> +exit
> diff --git a/tests/generic/764.out b/tests/generic/764.out
> new file mode 100644
> index 00000000..bb58e5b8
> --- /dev/null
> +++ b/tests/generic/764.out
> @@ -0,0 +1,2 @@
> +QA output created by 764
> +Silence is golden
> --
> 2.45.2
>
>
