overlay: test flock after copied up

Locks of file in lower dir should working after it's
been copied up.

CC: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Xiong Zhou <xzhou@redhat.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Eryu Guan <eguan@redhat.com>

tests/overlay/028

@@ -0,0 +1,81 @@
+#! /bin/bash
+# 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>
+#
+#-----------------------------------------------------------------------
+# Copyright (c) 2017 Red Hat Inc.  All Rights Reserved.
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it would be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write the Free Software Foundation,
+# Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+#-----------------------------------------------------------------------
+#
+
+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=$SCRATCH_DEV/$OVERLAY_LOWER_DIR
+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

tests/overlay/028.out

@@ -0,0 +1,2 @@
+QA output created by 028
+Silence is golden

tests/overlay/group

@@ -30,3 +30,4 @@
 025 auto quick attr
 026 auto attr quick
 027 auto quick perms
+028 auto copyup quick