--- /dev/null
+#! /bin/bash
+# FS QA Test 032
+#
+# Test concurrent copy up of lower hardlinks.
+#
+# Two tasks make a metadata change concurrently on two hardlinks of a large
+# lower inode. The copy up should be triggers by one of the tasks and the
+# other should be waiting for copy up to complete. Both copy up targets
+# should end up being upper hardlinks and both metadata changes should be
+# applied.
+#
+#-----------------------------------------------------------------------
+# 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
+
+# Remove all files from previous tests
+_scratch_mkfs
+
+# overlay copy_up doesn't deal with sparse file well, holes will be filled by
+# zeros, so if both hardlinks are broken on copy up, we need (2*1G) free space
+# on $OVL_BASE_SCRATCH_MNT.
+_require_fs_space $OVL_BASE_SCRATCH_MNT $((1024*1024*2))
+
+# Create a large file in lower with 2 hardlinks.
+# Make the file have non zero blocks, so copy up won't be able to do
+# a naive sparse file copy up optimization.
+lowerdir=$OVL_BASE_SCRATCH_MNT/$OVL_LOWER
+mkdir -p $lowerdir
+$XFS_IO_PROG -fc "pwrite 1g 4k" $lowerdir/zero >> $seqres.full
+ln $lowerdir/zero $lowerdir/one
+ln $lowerdir/zero $lowerdir/two
+
+_scratch_mount
+
+do_cmd()
+{
+ echo "`date +%T` $1..." >> $seqres.full
+ eval "$1"
+ echo "`date +%T` ...$1" >> $seqres.full
+}
+
+# Perform one modification on each hardlink (size and owner)
+do_cmd "echo >> $SCRATCH_MNT/one" &
+#
+# When hardlinks are broken and overlayfs supports concurrent copy up,
+# $seqres.full will show that file two copy up started ~2s after file one
+# copy up started and ended ~2s after file one copy up ended.
+# With synchronized copy up of lower inodes, $seqres.full will show that
+# file two copy up ended at the same time as file one copy up.
+# Without sparse file copy up optimizations, copy of 1g on a standard disk
+# is expected to take more than 2s.
+# If underlying filesystem supports clone, overlay clone up with take less
+# than 1s and this test will not be doing concurrent copy up of hardlinks,
+# but rather consequent copy up of hardlinks.
+#
+sleep 2
+do_cmd "chown 100 $SCRATCH_MNT/two" &
+
+wait
+
+# Expect all hardlinks to show both metadata modifications (owner and size).
+# List <nlink> <owner> <size> <name>:
+for f in zero one two; do
+ _ls_l -n $SCRATCH_MNT/$f | awk '{ print $2, $3, $5, $9 }' | _filter_scratch
+done
+
+status=0
+exit