overlay: permission check with cached acls in tmpfs

tmpfs does not implement ->get_acl method, overlayfs
need to get its cached acls in permission check when
lower or upper fs is tmpfs.

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

common/rc

@@ -1566,6 +1566,15 @@ _require_ext2()
     fi
 }
 
+# this test requires tmpfs filesystem support
+#
+_require_tmpfs()
+{
+	modprobe tmpfs >/dev/null 2>&1
+	grep -q tmpfs /proc/filesystems ||
+		_notrun "this test requires tmpfs support"
+}
+
 # this test requires that (large) loopback device files are not in use
 #
 _require_no_large_scratch_dev()

tests/overlay/025

@@ -0,0 +1,82 @@
+#! /bin/bash
+# FS QA Test 025
+#
+# Overlayfs failed to get posix acls if lower or upper
+# fs is tmpfs.
+# Kernel commit below fixed it.
+# 5201dc449e4b ovl: use cached acl on underlying layer
+#
+# 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 /
+	$UMOUNT_PROG $tmpfsdir/mnt
+	$UMOUNT_PROG $tmpfsdir
+	rm -rf $tmpfsdir
+	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_user
+_require_tmpfs
+
+# create a tmpfs in $TEST_DIR
+tmpfsdir=$TEST_DIR/tmpfs
+mkdir -p $tmpfsdir
+$MOUNT_PROG -t tmpfs tmpfs $tmpfsdir
+
+mkdir -p $tmpfsdir/{lower,upper,work,mnt}
+mkdir -p -m 0 $tmpfsdir/upper/testd
+# grant permission for $qa_user
+setfacl -m u:$qa_user:rx $tmpfsdir/upper/testd
+
+# mount overlay using dirs in tmpfs
+_overlay_mount_dirs $tmpfsdir/{lower,upper,work,overlay,mnt}
+
+# user accessing test dir, should be OKay
+_user_do "ls $tmpfsdir/mnt/testd"
+
+echo "Silence is golden"
+# success, all done
+status=0
+exit

tests/overlay/025.out

@@ -0,0 +1,2 @@
+QA output created by 025
+Silence is golden

tests/overlay/group

@@ -27,3 +27,4 @@
 022 auto quick
 023 auto quick attr
 024 auto quick
+025 auto quick attr