overlay: test overlay file handle of dir with ancestor under lower redirect

Overlayfs with nfs_export enabled, indexes all directories on copy
up.  Directory index is requires for decoding lower directory file
handles in case ancestors have been renamed.

When enabling nfs_export on an overlay that has merge dirs with
lower layer redirects, the possibility of ancestor rename requires
special handling when encoding lower directory file handles from
layer > 1.

- Check decode of lower dir with parent under lower redirect
- Check decode of lower dir with grandparent under lower redirect
- Check decode of lower dir after rename of lower redirected parent
- Check decode of lower dir after rename of lower redirected grandparent

This test requires and enables overlayfs NFS export support and
merge dir rename support (redirect_dir).
NFS export support depends on and requires overlayfs index feature.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Eryu Guan <eguan@redhat.com>
Signed-off-by: Eryu Guan <eguan@redhat.com>

tests/overlay/055

@@ -0,0 +1,170 @@
+#! /bin/bash
+# FS QA Test No. 055
+#
+# Test overlay file handle of dir with ancestor under lower redirect
+#
+# Overlayfs with nfs_export enabled, indexes all directories on copy up.
+# Directory index is requires for decoding lower directory file handles
+# in case ancestors have been renamed.
+#
+# When enabling nfs_export on an overlay that has merge dirs with lower
+# layer redirects, the possibility of ancestor rename requires special
+# handling when encoding lower directory file handles from layer > 1.
+#
+# - Check decode of lower dir with parent under lower redirect
+# - Check decode of lower dir with grandparent under lower redirect
+# - Check decode of lower dir after rename of lower redirected parent
+# - Check decode of lower dir after rename of lower redirected grandparent
+#
+# This test requires and enables overlayfs NFS export support and merge
+# dir rename support (redirect_dir).
+# NFS export support depends on and requires overlayfs index feature.
+#
+#-----------------------------------------------------------------------
+# Copyright (C) 2018 CTERA Networks. All Rights Reserved.
+# Author: Amir Goldstein <amir73il@gmail.com>
+#
+# 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.*
+	# Cleanup overlay scratch mount that is holding base test mount
+	# to prevent _check_test_fs and _test_umount from failing before
+	# _check_scratch_fs _scratch_umount
+	$UMOUNT_PROG $SCRATCH_MNT 2>/dev/null
+}
+
+# get standard environment, filters and checks
+. ./common/rc
+. ./common/filter
+
+# real QA test starts here
+
+_supported_fs overlay
+_supported_os Linux
+_require_test
+_require_scratch
+_require_test_program "open_by_handle"
+# We need to require all features together, because nfs_export cannot
+# be enabled when index is disabled
+_require_scratch_overlay_features index nfs_export redirect_dir
+
+# Lower is on test partition
+lower=$OVL_BASE_TEST_DIR/$OVL_LOWER-$seq
+# Upper/work are on scratch partition
+middle=$OVL_BASE_SCRATCH_MNT/$OVL_LOWER
+upper=$OVL_BASE_SCRATCH_MNT/$OVL_UPPER
+work=$OVL_BASE_SCRATCH_MNT/$OVL_WORK
+
+NUMFILES=1
+
+# Create test dir and empty test files
+create_test_files()
+{
+	local dir=$1
+	local opt=$2
+
+	mkdir -p $dir
+	$here/src/open_by_handle -cp $opt $dir $NUMFILES
+}
+
+# Test encode/decode file handles on overlay mount
+test_file_handles()
+{
+	local dir=$1
+	shift
+
+	echo test_file_handles $dir $* | _filter_scratch | \
+				sed -e "s,$tmp\.,,g"
+	$here/src/open_by_handle $* $dir $NUMFILES
+}
+
+# Re-create lower/middle/upper/work dirs
+create_dirs()
+{
+	# Create lower dir on test partition
+	rm -rf $lower
+	mkdir $lower
+
+	# Create middle/upper/work dirs on scratch partition
+	_scratch_mkfs
+}
+
+# Mount an overlay on $SCRATCH_MNT with lower layer on test partition
+# and middle and upper layer on scratch partition
+mount_dirs()
+{
+	_overlay_scratch_mount_dirs $middle:$lower $upper $work \
+				-o "index=on,nfs_export=on,redirect_dir=on"
+}
+
+# Unmount the overlay without unmounting base fs
+unmount_dirs()
+{
+	$UMOUNT_PROG $SCRATCH_MNT
+}
+
+# Check file handles of dir with ancestor under lower redirect
+create_dirs
+create_test_files $lower/origin -w
+create_test_files $lower/origin/dir -w
+create_test_files $lower/origin/dir/subdir -w
+create_test_files $lower/origin/parent/child -w
+# Create lower redirected merge dir
+mkdir $middle/merged
+setfattr -n "trusted.overlay.redirect" -v "origin" $middle/merged
+mount_dirs
+# Check encode/decode/read of lower dir with parent under lower redirect
+# This is expected to copy up merged/dir and encode an upper file handle
+test_file_handles $SCRATCH_MNT/merged/dir -p -o $tmp.dir_file_handles
+test -d $upper/merged/dir || echo "merged/dir not copied up"
+# Check encode/decode/read of lower dir with grandparent under lower redirect
+# This is expected to encode a lower file handle
+test_file_handles $SCRATCH_MNT/merged/dir/subdir -p -o $tmp.subdir_file_handles
+test -d $upper/merged/dir/subdir && echo "merged/dir/subdir unexpected copy up"
+# This is expected to copy up parent and encode a lower file handle
+test_file_handles $SCRATCH_MNT/merged/parent/child -p -o $tmp.child_file_handles
+test -d $upper/merged/parent || echo "merged/parent not copied up"
+test -d $upper/merged/parent/child && echo "merged/parent/child unexpected copy up"
+
+# Rename lower redirected merge dir
+mv $SCRATCH_MNT/merged $SCRATCH_MNT/merged.new/
+# Check open, read and readdir from stored file handles
+# (testdir argument is the mount point and NOT the dir
+#  we are trying to open by stored file handle)
+test_file_handles $SCRATCH_MNT -rp -i $tmp.dir_file_handles
+test_file_handles $SCRATCH_MNT -rp -i $tmp.subdir_file_handles
+test_file_handles $SCRATCH_MNT -rp -i $tmp.child_file_handles
+# Retry decoding lower subdir file handles when indexed ancestor is in dcache
+# (providing the ancestor dir argument pins the ancestor to dcache)
+test_file_handles $SCRATCH_MNT/merged.new/dir -rp -i $tmp.dir_file_handles
+test_file_handles $SCRATCH_MNT/merged.new/dir -rp -i $tmp.subdir_file_handles
+test_file_handles $SCRATCH_MNT/merged.new/parent -rp -i $tmp.child_file_handles
+unmount_dirs
+
+status=0
+exit

tests/overlay/055.out

@@ -0,0 +1,10 @@
+QA output created by 055
+test_file_handles SCRATCH_MNT/merged/dir -p -o dir_file_handles
+test_file_handles SCRATCH_MNT/merged/dir/subdir -p -o subdir_file_handles
+test_file_handles SCRATCH_MNT/merged/parent/child -p -o child_file_handles
+test_file_handles SCRATCH_MNT -rp -i dir_file_handles
+test_file_handles SCRATCH_MNT -rp -i subdir_file_handles
+test_file_handles SCRATCH_MNT -rp -i child_file_handles
+test_file_handles SCRATCH_MNT/merged.new/dir -rp -i dir_file_handles
+test_file_handles SCRATCH_MNT/merged.new/dir -rp -i subdir_file_handles
+test_file_handles SCRATCH_MNT/merged.new/parent -rp -i child_file_handles

tests/overlay/group

@@ -55,3 +55,4 @@
 052 auto quick copyup redirect exportfs
 053 auto quick copyup redirect exportfs nonsamefs
 054 auto quick copyup redirect exportfs
+055 auto quick copyup redirect exportfs nonsamefs