+#! /bin/bash
+# FS QA Test No. 026
+#
+# Tests file clone functionality of btrfs ("reflinks"):
+# - Reflink a file
+# - Reflink the reflinked file
+# - Modify the original file
+# - Modify the reflinked file
+#
+#-----------------------------------------------------------------------
+# Copyright (c) 2014, Oracle and/or its affiliates. All Rights Reserved.
+#
+# 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`
+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 $tmp.*
+}
+
+# get standard environment, filters and checks
+. common/rc
+. common/filter
+
+# real QA test starts here
+_supported_fs btrfs
+_supported_os Linux
+
+_require_xfs_io_fiemap
+_require_cp_reflink
+
+TESTDIR1=$TEST_DIR/test-$seq
+rm -rf $TESTDIR1
+mkdir $TESTDIR1
+
+_checksum_files() {
+ for F in original copy1 copy2
+ do
+ md5sum $TESTDIR1/$F | _filter_test_dir
+ done
+}
+
+rm -f $seqres.full
+
+echo "Create the original file and reflink to copy1, copy2"
+$XFS_IO_PROG -f -c 'pwrite -S 0x61 0 9000' $TESTDIR1/original \
+ >> $seqres.full 2>&1
+cp --reflink $TESTDIR1/original $TESTDIR1/copy1
+cp --reflink $TESTDIR1/copy1 $TESTDIR1/copy2
+_verify_reflink $TESTDIR1/original $TESTDIR1/copy1
+_verify_reflink $TESTDIR1/original $TESTDIR1/copy2
+echo "Original md5sums:"
+_checksum_files
+
+echo "Overwrite original file with new data"
+$XFS_IO_PROG -c 'pwrite -S 0x62 0 9000' $TESTDIR1/original \
+ >> $seqres.full 2>&1
+echo "md5sums after overwriting original:"
+_checksum_files
+
+echo "Overwrite copy1 with different new data"
+$XFS_IO_PROG -c 'pwrite -S 0x63 0 9000' $TESTDIR1/copy1 \
+ >> $seqres.full 2>&1
+echo "md5sums after overwriting copy1:"
+_checksum_files
+
+# success, all done
+status=0
+exit