#! /bin/bash
# SPDX-License-Identifier: GPL-2.0
# Copyright (c) 2022 Oracle.  All Rights Reserved.
# Copyright (c) 2024 CTERA Networks.  All Rights Reserved.
#
# FS QA Test No. 087
#
# This is a variant of test xfs/546 for overlayfs
# with and without the "volatile" mount option.
# It only works over xfs underlying fs.
#
# Regression test for kernel commits:
#
# 5679897eb104 ("vfs: make sync_filesystem return errors from ->sync_fs")
# 2d86293c7075 ("xfs: return errors in xfs_fs_sync_fs")
#
# 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 mount shutdown


# Modify as appropriate.
_require_scratch_nocheck
_require_scratch_shutdown_and_syncfs

[ "$OVL_BASE_FSTYP" == "xfs" ] || \
	_notrun "base fs $OVL_BASE_FSTYP has unknown behavior with syncfs after 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.
echo "=== syncfs after shutdown"
_scratch_mount
_scratch_shutdown_and_syncfs

# Now repeat the same test with a volatile overlayfs mount and expect no error
_scratch_unmount
echo "=== syncfs after shutdown (volatile)"
_scratch_mount -o volatile
_scratch_shutdown_and_syncfs

# success, all done
status=0
exit
