[PATCH 2/2] overlay/072: test for sharing inode with whiteout files

[Chengguang Xu <cgxu519@mykernel.net>]

This is a test for whiteout inode sharing feature.

Signed-off-by: Chengguang Xu <cgxu519@mykernel.net>
---
Hi Eryu,

Kernel patch of this feature is still in review but I hope to merge
test case first, so that we can check the correctness in a convenient
way. The test case will carefully check new module param and skip the
test if the param does not exist.


 tests/overlay/072     | 148 ++++++++++++++++++++++++++++++++++++++++++
 tests/overlay/072.out |   2 +
 tests/overlay/group   |   1 +
 3 files changed, 151 insertions(+)
 create mode 100755 tests/overlay/072
 create mode 100644 tests/overlay/072.out

diff --git a/tests/overlay/072 b/tests/overlay/072
new file mode 100755
index 00000000..1cff386d
--- /dev/null
+++ b/tests/overlay/072
@@ -0,0 +1,148 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2020 Chengguang Xu <cgxu519@mykernel.net>.
+# All Rights Reserved.
+#
+# FS QA Test 072
+#
+# This is a test for inode sharing with whiteout files.
+#
+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
+_supported_fs overlay
+_supported_os Linux
+_require_test
+_require_scratch
+
+param_name="whiteout_link_max"
+check_whiteout_link_max()
+{
+	local param_value=`_get_fs_module_param ${param_name}`
+	if [ -z ${param_value} ]; then
+		_notrun "${FSTYP} module param ${param_name} does not exist"
+	fi
+}
+
+lowerdir=$OVL_BASE_SCRATCH_MNT/$OVL_LOWER
+upperdir=$OVL_BASE_SCRATCH_MNT/$OVL_UPPER
+merged=$OVL_BASE_SCRATCH_MNT/$OVL_MNT
+
+#Make some files in lowerdir.
+make_lower_files()
+{
+	seq 1 $file_count | while read line; do
+		`touch $lowerdir/test${line} 1>&2 2>/dev/null`
+	done
+}
+
+#Delete all copy-uped files in upperdir.
+make_whiteout_files()
+{
+	rm -f $merged/* 1>&2 2>/dev/null
+}
+
+#Check link count of whiteout files.
+check_whiteout_files()
+{
+	seq 1 $file_count | while read line; do
+		local real_count=`stat -c %h $upperdir/test${line} 2>/dev/null`
+		if [[ $link_count != $real_count ]]; then
+			echo "Expected whiteout link count is $link_count but real count is $real_count"
+		fi
+	done
+}
+
+check_whiteout_link_max
+
+# Case1:
+# Setting whiteout_link_max=0 will not share inode
+# with whiteout files, it means each whiteout file
+# will has it's own inode.
+
+file_count=10
+link_max=0
+link_count=1
+_scratch_mkfs
+_set_fs_module_param $param_name $link_max
+make_lower_files
+_scratch_mount
+make_whiteout_files
+check_whiteout_files
+$UMOUNT_PROG $OVL_BASE_SCRATCH_MNT/$OVL_MNT
+
+# Case2:
+# Setting whiteout_link_max=1 will not share inode
+# with whiteout files, it means each whiteout file
+# will has it's own inode.
+
+file_count=10
+link_max=1
+link_count=1
+_scratch_mkfs
+_set_fs_module_param $param_name $link_max
+make_lower_files
+_scratch_mount
+make_whiteout_files
+check_whiteout_files $link_count
+$UMOUNT_PROG $OVL_BASE_SCRATCH_MNT/$OVL_MNT
+
+# Case3:
+# Setting whiteout_link_max=2 will not share inode
+# with whiteout files, it means each whiteout file
+# will has it's own inode. However, the inode will
+# be shared with tmpfile(in workdir) which is used
+# for creating whiteout file.
+
+file_count=10
+link_max=2
+link_count=2
+_scratch_mkfs
+_set_fs_module_param $param_name $link_max
+make_lower_files
+_scratch_mount
+make_whiteout_files
+check_whiteout_files
+$UMOUNT_PROG $OVL_BASE_SCRATCH_MNT/$OVL_MNT
+
+# Case4:
+# Setting whiteout_link_max=10 will share inode
+# with 9 whiteout files and meanwhile the inode
+# will also share with tmpfile(in workdir) which
+# is used for creating whiteout file.
+
+file_count=18
+link_max=10
+link_count=10
+_scratch_mkfs
+_set_fs_module_param $param_name $link_max
+make_lower_files
+_scratch_mount
+make_whiteout_files
+check_whiteout_files
+$UMOUNT_PROG $OVL_BASE_SCRATCH_MNT/$OVL_MNT
+
+# success, all done
+echo "Silence is golden"
+status=0
+exit
diff --git a/tests/overlay/072.out b/tests/overlay/072.out
new file mode 100644
index 00000000..590bbc6c
--- /dev/null
+++ b/tests/overlay/072.out
@@ -0,0 +1,2 @@
+QA output created by 072
+Silence is golden
diff --git a/tests/overlay/group b/tests/overlay/group
index 43ad8a52..8b2276f1 100644
--- a/tests/overlay/group
+++ b/tests/overlay/group
@@ -74,3 +74,4 @@
 069 auto quick copyup hardlink exportfs nested nonsamefs
 070 auto quick copyup redirect nested
 071 auto quick copyup redirect nested nonsamefs
+072 auto quick whiteout
-- 
2.20.1