apfstests/tests/overlay/028

#! /bin/bash
# SPDX-License-Identifier: GPL-2.0
# Copyright (c) 2017 Red Hat Inc.  All Rights Reserved.
#
# FS QA Test 028
#
# When file in lower dir is locked and it's been copied up,
# make sure the lock is working in overlayfs.
#
# Kernel commit below fixed it.
# c568d68341be locks: fix file locking on overlayfs
#
# This reproducer was originally written by
#     Miklos Szeredi <mszeredi@redhat.com>
#
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

# remove previous $seqres.full before test
rm -f $seqres.full

# real QA test starts here

# Modify as appropriate.
_supported_fs overlay
_supported_os Linux
_require_scratch
_require_command "$FLOCK_PROG" flock

# Remove all files from previous tests
_scratch_mkfs

lowerdir=$OVL_BASE_SCRATCH_MNT/$OVL_LOWER
mkdir -p $lowerdir
touch $lowerdir/foo

# Mounting overlay
_scratch_mount

# Testing copyup and flock
flock $SCRATCH_MNT/foo sleep 3 &
# flock in subshell should fail with no output
(sleep 1; echo bar > $SCRATCH_MNT/foo; \
  flock -n $SCRATCH_MNT/foo echo LOCKED)

wait
echo "Silence is golden"
# success, all done
status=0
exit