overlay: regression test for orphan index cleanup on mount

Test nlink accounting of overlay hardlinks with offline modifications.

nlink of overlay inode should account for the union of lower and upper
hardlinks. Orphan index inodes with union nlink 0 should be cleaned on
mount.

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

3 files changed, 160 insertions, 0 deletions

diff --git a/tests/overlay/048 b/tests/overlay/048
new file mode 100755
index 0000000000..4b2c58f438
--- /dev/null
+++ b/tests/overlay/048
@@ -0,0 +1,141 @@
+#! /bin/bash
+# FS QA Test 048
+#
+# Test nlink accounting of overlay hardlinks with offline modifications.
+#
+# nlink of overlay inode should account for the union of lower and upper
+# hardlinks. Orphan index inodes with union nlink 0 should be cleaned on
+# mount.
+#
+#-----------------------------------------------------------------------
+# Copyright (C) 2017 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"
+
+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_scratch
+_require_scratch_feature index
+
+report_nlink()
+{
+	when=$1
+
+	# mount and check nlink after overlay offline modification
+	_scratch_mount -o index=on
+
+	# List <nlink> <name>
+	echo "== $when offline =="
+	for f in $HARDLINKS; do
+		_ls_l $SCRATCH_MNT/$f | awk '{ print $2, $9 }' | _filter_scratch
+	done
+
+	$UMOUNT_PROG $SCRATCH_MNT
+}
+
+# Create lower hardlinks
+create_hardlinks()
+{
+	mkdir -p $lowerdir
+	touch $lowerdir/0
+	ln $lowerdir/0 $lowerdir/1
+	ln $lowerdir/0 $lowerdir/2
+}
+
+test_hardlinks_offline()
+{
+	HARDLINKS=`seq 0 2`
+	report_nlink "all upper"
+
+	# Unlink copied up hardlink
+	rm $upperdir/0
+	HARDLINKS=`seq 1 2`
+	report_nlink "unlink upper"
+
+	# Link to copied up hardlink
+	ln $upperdir/2 $upperdir/3
+	HARDLINKS=`seq 1 3`
+	report_nlink "link upper"
+
+	# Rename over copied up hardlink
+	touch $upperdir/new
+	mv $upperdir/new $upperdir/1
+	HARDLINKS=`seq 2 3`
+	report_nlink "rename over upper"
+
+	# Unlink new upper hardlink
+	rm $upperdir/3
+	HARDLINKS=2
+	report_nlink "unlink new upper"
+
+	# Unlink last upper and drop union nlink to zero
+	rm $upperdir/2
+
+	HARDLINKS=
+	report_nlink "unlink last lower"
+
+	# Verify that orphan index is cleaned when dropping nlink to zero
+	ls $workdir/index
+}
+
+lowerdir=$OVL_BASE_SCRATCH_MNT/$OVL_LOWER
+upperdir=$OVL_BASE_SCRATCH_MNT/$OVL_UPPER
+workdir=$OVL_BASE_SCRATCH_MNT/$OVL_WORK
+
+# Remove all files from previous tests
+_scratch_mkfs
+
+# Create lower hardlinks
+create_hardlinks
+
+# Enable overlay index feature to prevent breaking hardlinks on copy up
+_scratch_mount -o index=on
+
+# Copy up and index hardlinks
+touch $SCRATCH_MNT/0
+touch $SCRATCH_MNT/1
+touch $SCRATCH_MNT/2
+
+# Perform the rest of the changes offline
+$UMOUNT_PROG $SCRATCH_MNT
+
+test_hardlinks_offline
+
+status=0
+exit
diff --git a/tests/overlay/048.out b/tests/overlay/048.out
new file mode 100644
index 0000000000..0527dec584
--- /dev/null
+++ b/tests/overlay/048.out
@@ -0,0 +1,18 @@
+QA output created by 048
+== all upper offline ==
+3 SCRATCH_MNT/0
+3 SCRATCH_MNT/1
+3 SCRATCH_MNT/2
+== unlink upper offline ==
+2 SCRATCH_MNT/1
+2 SCRATCH_MNT/2
+== link upper offline ==
+3 SCRATCH_MNT/1
+3 SCRATCH_MNT/2
+3 SCRATCH_MNT/3
+== rename over upper offline ==
+2 SCRATCH_MNT/2
+2 SCRATCH_MNT/3
+== unlink new upper offline ==
+1 SCRATCH_MNT/2
+== unlink last lower offline ==
diff --git a/tests/overlay/group b/tests/overlay/group
index 3e31d2df65..7e541e4538 100644
--- a/tests/overlay/group
+++ b/tests/overlay/group
@@ -48,3 +48,4 @@
 043 auto quick copyup nonsamefs
 044 auto quick copyup hardlink nonsamefs
 047 auto quick copyup hardlink
+048 auto quick copyup hardlink