On Mon, Apr 11, 2022 at 03:54:37PM -0700, Darrick J. Wong wrote:
> From: Darrick J. Wong <djwong@xxxxxxxxxx>
>
> This is a regression test to make sure that nonzero error returns from
> a filesystem's ->sync_fs implementation are actually passed back to
> userspace when the call stack involves syncfs(2).
>
> Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
> ---
> tests/xfs/839 | 42 ++++++++++++++++++++++++++++++++++++++++++
> tests/xfs/839.out | 2 ++
> 2 files changed, 44 insertions(+)
> create mode 100755 tests/xfs/839
> create mode 100644 tests/xfs/839.out
>
>
> diff --git a/tests/xfs/839 b/tests/xfs/839
This case looks good to me. Just one question, is it possible to be a generic
case? From the code logic, it doesn't use xfs specified operations, but I'm
not sure if other filesystems would like to treat sync_fs return value as XFS.
> new file mode 100755
> index 00000000..9bfe93ef
> --- /dev/null
> +++ b/tests/xfs/839
> @@ -0,0 +1,42 @@
> +#! /bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (c) 2022 Oracle. All Rights Reserved.
> +#
> +# FS QA Test No. 839
> +#
> +# Regression test for kernel commits:
> +#
> +# 5679897eb104 ("vfs: make sync_filesystem return errors from ->sync_fs")
> +# 2d86293c7075 ("xfs: return errors in xfs_fs_sync_fs")
BTW, after this change, now can I assume that sync(2) flushes all data and metadata
to underlying disk, if it returns 0. Sorry, really confused on what these sync things
really guarantee :)
Thanks,
Zorro
> +#
> +# During a code inspection, I noticed that sync_filesystem ignores the return
> +# value of the ->sync_fs calls that it makes. sync_filesystem, in turn is used
> +# by the syncfs(2) syscall to persist filesystem changes to disk. This means
> +# that syncfs(2) does not capture internal filesystem errors that are neither
> +# visible from the block device (e.g. media error) nor recorded in s_wb_err.
> +# XFS historically returned 0 from ->sync_fs even if there were log failures,
> +# so that had to be corrected as well.
> +#
> +# The kernel commits above fix this problem, so this test tries to trigger the
> +# bug by using the shutdown ioctl on a clean, freshly mounted filesystem in the
> +# hope that the EIO generated as a result of the filesystem being shut down is
> +# only visible via ->sync_fs.
> +#
> +. ./common/preamble
> +_begin_fstest auto quick shutdown
> +
> +# real QA test starts here
> +
> +# Modify as appropriate.
> +_require_xfs_io_command syncfs
> +_require_scratch_nocheck
> +_require_scratch_shutdown
> +
> +# Reuse the fs formatted when we checked for the shutdown ioctl, and don't
> +# bother checking the filesystem afterwards since we never wrote anything.
> +_scratch_mount
> +$XFS_IO_PROG -x -c 'shutdown -f ' -c syncfs $SCRATCH_MNT
> +
> +# success, all done
> +status=0
> +exit
> diff --git a/tests/xfs/839.out b/tests/xfs/839.out
> new file mode 100644
> index 00000000..f275cdcc
> --- /dev/null
> +++ b/tests/xfs/839.out
> @@ -0,0 +1,2 @@
> +QA output created by 839
> +syncfs: Input/output error
>
