overlay: test decoding overlay file handles with warm/cold dentry cache

When opening a non-dir by file handle and the decoded inode/dentry
are not in cache, the resulting dentry is "disconnected" (i.e. unknown
path). This is a common case that is already covered by previous tests.
This test covers the case of decoding an overlay file handle, while a
disconnected dentry is still in cache.

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

tests/overlay/058

@@ -0,0 +1,137 @@
+#! /bin/bash
+# FS QA Test No. 058
+#
+# Test decoding overlay file handles with warm/cold dentry cache
+#
+# When opening a non-dir by file handle and the decoded inode/dentry
+# are not in cache, the resulting dentry is "disconnected" (i.e. unknown
+# path). This is a common case that is already covered by previous tests.
+# This test covers the case of decoding an overlay file handle, while a
+# disconnected dentry is still in cache.
+#
+# This test requires and enables overlayfs NFS export support.
+# 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()
+{
+	$KILLALL_PROG -9 open_by_handle >/dev/null 2>&1
+	wait
+	cd /
+	rm -f $tmp.*
+}
+
+# get standard environment, filters and checks
+. ./common/rc
+. ./common/filter
+
+# real QA test starts here
+
+_supported_fs overlay
+_supported_os Linux
+_require_scratch
+_require_test_program "open_by_handle"
+# We need to require all features together, because nfs_export cannot
+# be enabled when index is disabled
+_require_scratch_overlay_features index nfs_export
+_require_command "$KILLALL_PROG" killall
+
+# All overlay dirs are on scratch partition
+lower=$OVL_BASE_SCRATCH_MNT/$OVL_LOWER
+upper=$OVL_BASE_SCRATCH_MNT/$OVL_UPPER
+work=$OVL_BASE_SCRATCH_MNT/$OVL_WORK
+
+# Keep this number > 1, because open_by_handle -rp does faccessat()
+# on file file000000, which makes that dentry connected
+NUMFILES=10
+
+# 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
+}
+
+# Create lower/upper dir and files
+_scratch_mkfs
+create_test_files $upper/uppertestdir -w
+create_test_files $lower/lowertestdir -w
+_scratch_mount -o "index=on,nfs_export=on"
+# Encode upper file handles
+test_file_handles $SCRATCH_MNT/uppertestdir -p -o $tmp.upper_file_handles
+# Encode lower file handles
+test_file_handles $SCRATCH_MNT/lowertestdir -p -o $tmp.lower_file_handles
+
+# Check decode and read from stored file handles with warm caches -
+# At this time, all non-dir dentries are connected, because the entries
+# were created on lookup, before encoding the file handles.
+test_file_handles $SCRATCH_MNT -rnp -i $tmp.upper_file_handles
+test_file_handles $SCRATCH_MNT -rnp -i $tmp.lower_file_handles
+
+# Check decode and read/readdir from stored file handles with cold caches -
+# -s sleeps in the background to keep files open and keep disconnected
+# overlay dentries in cache
+_scratch_cycle_mount "index=on,nfs_export=on"
+test_file_handles $SCRATCH_MNT -rnps -i $tmp.upper_file_handles &
+# Give the above 1 second to get to sleep loop
+sleep 1
+test_file_handles $SCRATCH_MNT -rnps -i $tmp.lower_file_handles &
+# Give the above 1 second to get to sleep loop
+sleep 1
+
+# Check decode and read/readdir from stored file handles with warm caches -
+# At this time, all non-dir dentries are disconnected, because there was
+# no lookup to the files since drop caches. The expection to this rule
+# is lower and upper file000000. open_by_handle -rp above did faccessat()
+# on file file000000, which created a connected dentry alias in addition
+# to the disconnected dentry alias.
+test_file_handles $SCRATCH_MNT -rnp -i $tmp.upper_file_handles
+test_file_handles $SCRATCH_MNT -rnp -i $tmp.lower_file_handles
+
+# SIGPIPE avoids Terminated/Killed message from bash
+$KILLALL_PROG -q -13 open_by_handle
+wait
+
+status=0
+exit

tests/overlay/058.out

@@ -0,0 +1,9 @@
+QA output created by 058
+test_file_handles SCRATCH_MNT/uppertestdir -p -o upper_file_handles
+test_file_handles SCRATCH_MNT/lowertestdir -p -o lower_file_handles
+test_file_handles SCRATCH_MNT -rnp -i upper_file_handles
+test_file_handles SCRATCH_MNT -rnp -i lower_file_handles
+test_file_handles SCRATCH_MNT -rnps -i upper_file_handles
+test_file_handles SCRATCH_MNT -rnps -i lower_file_handles
+test_file_handles SCRATCH_MNT -rnp -i upper_file_handles
+test_file_handles SCRATCH_MNT -rnp -i lower_file_handles

tests/overlay/group

@@ -60,3 +60,4 @@
 055 auto quick copyup redirect exportfs nonsamefs
 056 auto quick fsck
 057 auto quick redirect
+058 auto quick exportfs