tests: add basic overlayfs tests

Signed-off-by: Pavel Snajdr <snajpa@snajpa.net>

configure.ac

@@ -332,6 +332,7 @@ AC_CONFIG_FILES([
 	tests/zfs-tests/tests/functional/no_space/Makefile
 	tests/zfs-tests/tests/functional/nopwrite/Makefile
 	tests/zfs-tests/tests/functional/online_offline/Makefile
+	tests/zfs-tests/tests/functional/overlayfs/Makefile
 	tests/zfs-tests/tests/functional/pool_checkpoint/Makefile
 	tests/zfs-tests/tests/functional/pool_names/Makefile
 	tests/zfs-tests/tests/functional/poolversion/Makefile

tests/runfiles/linux.run

@@ -83,6 +83,10 @@ tags = ['functional', 'io']
 tests = ['mmap_libaio_001_pos']
 tags = ['functional', 'mmap']
 
+[tests/functional/overlayfs:Linux]
+tests = ['overlayfs_basic', 'overlayfs_layered']
+tags = ['functional', 'overlayfs']
+
 [tests/functional/projectquota:Linux]
 tests = ['projectid_001_pos', 'projectid_002_pos', 'projectid_003_pos',
     'projectquota_001_pos', 'projectquota_002_pos', 'projectquota_003_pos',

tests/zfs-tests/tests/functional/Makefile.am

@@ -44,6 +44,7 @@ SUBDIRS = \
 	no_space \
 	nopwrite \
 	online_offline \
+	overlayfs \
 	pool_checkpoint \
 	pool_names \
 	poolversion \

tests/zfs-tests/tests/functional/overlayfs/Makefile.am

@@ -0,0 +1,6 @@
+pkgdatadir = $(datadir)/@PACKAGE@/zfs-tests/tests/functional/overlayfs
+dist_pkgdata_SCRIPTS = \
+	setup.ksh \
+	cleanup.ksh \
+	overlayfs_basic.ksh \
+	overlayfs_layered.ksh

tests/zfs-tests/tests/functional/overlayfs/cleanup.ksh

@@ -0,0 +1,34 @@
+#!/bin/ksh -p
+#
+# CDDL HEADER START
+#
+# The contents of this file are subject to the terms of the
+# Common Development and Distribution License (the "License").
+# You may not use this file except in compliance with the License.
+#
+# You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+# or http://www.opensolaris.org/os/licensing.
+# See the License for the specific language governing permissions
+# and limitations under the License.
+#
+# When distributing Covered Code, include this CDDL HEADER in each
+# file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+# If applicable, add the following below this CDDL HEADER, with the
+# fields enclosed by brackets "[]" replaced with your own identifying
+# information: Portions Copyright [yyyy] [name of copyright owner]
+#
+# CDDL HEADER END
+#
+
+#
+# Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
+# Use is subject to license terms.
+#
+
+#
+# Copyright (c) 2013 by Delphix. All rights reserved.
+#
+
+. $STF_SUITE/include/libtest.shlib
+
+default_cleanup

tests/zfs-tests/tests/functional/overlayfs/overlayfs_basic.ksh

@@ -0,0 +1,66 @@
+#!/bin/ksh -p
+# SPDX-License-Identifier: CDDL-1.0 OR MPL-2.0
+
+#
+# CDDL HEADER START
+#
+# The contents of this file are subject to the terms of the
+# Common Development and Distribution License (the "License").
+# You may not use this file except in compliance with the License.
+#
+# You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+# or http://www.opensolaris.org/os/licensing.
+# See the License for the specific language governing permissions
+# and limitations under the License.
+#
+# When distributing Covered Code, include this CDDL HEADER in each
+# file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+# If applicable, add the following below this CDDL HEADER, with the
+# fields enclosed by brackets "[]" replaced with your own identifying
+# information: Portions Copyright [yyyy] [name of copyright owner]
+#
+# CDDL HEADER END
+#
+
+#
+# Copyright (C) 2019 Pavel Snajdr <snajpa@snajpa.net
+# Copyright (C) 2019 vpsFree.cz
+#
+
+. $STF_SUITE/include/libtest.shlib
+
+verify_runnable "both"
+
+function cleanup
+{
+	log_must umount -f $TESTDIR/overlay
+	log_must rm -rf $TESTDIR/*
+}
+
+log_assert "ZFS supports being upper/lower/mnt of overlayfs."
+log_onexit cleanup
+
+cd $TESTDIR
+mkdir lower upper work overlay
+touch lower/{a,b}
+touch upper/{c,d}
+echo "orig" > lower/testfile
+echo "upper" > upper/testfile
+
+# Basic overlayfs mount
+log_must mount -t overlay \
+    -o lowerdir=lower/,upperdir=upper/,workdir=work/ \
+    none overlay/
+
+# Does presented overlay have all the files we expect?
+log_must stat overlay/{a,b,c,d,testfile}
+
+# We'd expect content of the upper test file
+log_must grep upper overlay/testfile
+
+echo "new" > overlay/testfile
+
+# We'd expect content of the upper test file changed now
+log_must grep new upper/testfile
+
+log_assert "ZFS supports being upper/lower/mnt of overlayfs as expected."

tests/zfs-tests/tests/functional/overlayfs/overlayfs_layered.ksh

@@ -0,0 +1,78 @@
+#!/bin/ksh -p
+# SPDX-License-Identifier: CDDL-1.0 OR MPL-2.0
+
+#
+# CDDL HEADER START
+#
+# The contents of this file are subject to the terms of the
+# Common Development and Distribution License (the "License").
+# You may not use this file except in compliance with the License.
+#
+# You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+# or http://www.opensolaris.org/os/licensing.
+# See the License for the specific language governing permissions
+# and limitations under the License.
+#
+# When distributing Covered Code, include this CDDL HEADER in each
+# file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+# If applicable, add the following below this CDDL HEADER, with the
+# fields enclosed by brackets "[]" replaced with your own identifying
+# information: Portions Copyright [yyyy] [name of copyright owner]
+#
+# CDDL HEADER END
+#
+
+#
+# Copyright (C) 2019 Pavel Snajdr <snajpa@snajpa.net
+# Copyright (C) 2019 vpsFree.cz
+#
+
+. $STF_SUITE/include/libtest.shlib
+
+verify_runnable "both"
+
+function cleanup
+{
+	log_must umount -f $TESTDIR/merge{2,1}
+	log_must rm -rf $TESTDIR/*
+}
+
+log_assert "ZFS supports multilayered overlayfs."
+log_onexit cleanup
+
+cd $TESTDIR
+mkdir lower middle upper work1 work2 merge1 merge2
+mkdir {lower,middle,upper}/{dira,dirb}
+touch lower/{dira,dirb}/{a,b}
+touch middle/{dira,dirb}/{c,d}
+touch upper/{dira,dirb}/{e,f}
+echo "orig" > lower/testfile
+echo "mid" > middle/testfile
+echo "upper" > upper/testfile
+
+# 1st level overlayfs mount
+log_must mount -t overlay \
+    -o lowerdir=lower/,upperdir=middle/,workdir=work1/ \
+    -o ro \
+    none merge1/
+
+# 2st level overlayfs mount
+log_must mount -t overlay \
+    -o lowerdir=merge1/,upperdir=upper/,workdir=work2/ \
+    none merge2/
+
+# Does presented overlay have all the files we expect?
+log_must stat merge2/{dira,dirb}/{a,b,c,d,e,f} merge2/testfile
+
+# We'd expect content of the upper test file
+log_must grep upper merge2/testfile
+
+echo "new" > merge2/testfile
+
+# We'd expect content of the lower test file not changed
+log_must grep orig lower/testfile
+
+# We'd expect content of the upper test file changed to new
+log_must grep new upper/testfile
+
+log_assert "ZFS supports multi-layered overlayfs as expected."

tests/zfs-tests/tests/functional/overlayfs/setup.ksh

@@ -0,0 +1,43 @@
+#!/bin/ksh -p
+#
+# CDDL HEADER START
+#
+# The contents of this file are subject to the terms of the
+# Common Development and Distribution License (the "License").
+# You may not use this file except in compliance with the License.
+#
+# You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+# or http://www.opensolaris.org/os/licensing.
+# See the License for the specific language governing permissions
+# and limitations under the License.
+#
+# When distributing Covered Code, include this CDDL HEADER in each
+# file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+# If applicable, add the following below this CDDL HEADER, with the
+# fields enclosed by brackets "[]" replaced with your own identifying
+# information: Portions Copyright [yyyy] [name of copyright owner]
+#
+# CDDL HEADER END
+#
+
+#
+# Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
+# Use is subject to license terms.
+#
+
+#
+# Copyright (c) 2013 by Delphix. All rights reserved.
+#
+
+. $STF_SUITE/include/libtest.shlib
+
+if ! is_linux ; then
+	log_unsupported "overlayfs is linux-only"
+elif ! grep overlay /proc/filesystems; then
+	log_unsupported "kernel built without overlayfs or module not loaded"
+elif ! renameat2 -C ; then
+	log_unsupported "renameat2 not supported on this (pre-3.15) linux kernel"
+fi
+
+DISK=${DISKS%% *}
+default_setup $DISK