reflink: test adjacency of reflinked blocks

If we reflink a file with N blocks to another file one block at a time,
does the destination file end up with the same number of extents as the
source file?  In other words, does the filesystem succeed at combining
adjacent mappings into a maximal extents?

Signed-off-by: Darrick J. Wong <djwong@djwong.org>
Reviewed-by: Eryu Guan <eguan@redhat.com>
Signed-off-by: Eryu Guan <eguan@redhat.com>

tests/generic/414

@@ -0,0 +1,106 @@
+#! /bin/bash
+# FS QA Test No. 414
+#
+# Check that reflinking adjacent blocks in a file produces a single
+# block mapping extent.
+#
+#-----------------------------------------------------------------------
+# Copyright (c) 2017 Oracle, Inc.  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 $0`
+seqres=$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 7 15
+
+_cleanup()
+{
+	cd /
+	rm -rf $tmp.*
+	wait
+}
+
+# get standard environment, filters and checks
+. ./common/rc
+. ./common/filter
+. ./common/reflink
+
+# real QA test starts here
+_supported_os Linux
+_supported_fs generic
+_require_scratch_reflink
+_require_fiemap
+
+echo "Format and mount"
+_scratch_mkfs > $seqres.full 2>&1
+_scratch_mount >> $seqres.full 2>&1
+
+testdir=$SCRATCH_MNT/test-$seq
+mkdir $testdir
+
+blocks=32
+blksz=65536
+sz=$((blocks * blksz))
+
+echo "Create the original files"
+$XFS_IO_PROG -f -c "falloc 0 $sz" $testdir/file1 >> $seqres.full
+_pwrite_byte 0x61 0 $sz $testdir/file1 >> $seqres.full
+seq 0 $blksz $((sz - blksz)) | while read offset; do
+	_reflink_range $testdir/file1 $offset $testdir/file2 $offset $blksz >> $seqres.full
+done
+
+echo "Compare files"
+md5sum $testdir/file1 | _filter_scratch
+md5sum $testdir/file2 | _filter_scratch
+
+echo "Check extent counts"
+f1=$(_count_extents $testdir/file1)
+f2=$(_count_extents $testdir/file2)
+s1=$($XFS_IO_PROG -c 'fiemap -v' $testdir/file1 | awk '{print $5}' | grep -c '0x.*[2367aAbBfF]...$')
+s2=$($XFS_IO_PROG -c 'fiemap -v' $testdir/file2 | awk '{print $5}' | grep -c '0x.*[2367aAbBfF]...$')
+
+# Did the fs combine the extent mappings when we made f2?
+test $f1 -eq $f2 || echo "f1 ($f1) != f2 ($f2)"
+test $s1 -eq $s2 || echo "s1 ($s1) != s2 ($s2)"
+test $f1 -eq $s1 || echo "f1 ($f1) != s1 ($f1)"
+test $f2 -eq $s2 || echo "f2 ($f2) != s2 ($f2)"
+
+_scratch_cycle_mount
+
+echo "Compare files after remounting"
+md5sum $testdir/file1 | _filter_scratch
+md5sum $testdir/file2 | _filter_scratch
+
+echo "Check extent counts"
+f1=$(_count_extents $testdir/file1)
+f2=$(_count_extents $testdir/file2)
+s1=$($XFS_IO_PROG -c 'fiemap -v' $testdir/file1 | awk '{print $5}' | grep -c '0x.*[2367aAbBfF]...$')
+s2=$($XFS_IO_PROG -c 'fiemap -v' $testdir/file2 | awk '{print $5}' | grep -c '0x.*[2367aAbBfF]...$')
+
+# Are the mappings still combined?
+test $f1 -eq $f2 || echo "f1 ($f1) != f2 ($f2)"
+test $s1 -eq $s2 || echo "s1 ($s1) != s2 ($s2)"
+test $f1 -eq $s1 || echo "f1 ($f1) != s1 ($f1)"
+test $f2 -eq $s2 || echo "f2 ($f2) != s2 ($f2)"
+
+# success, all done
+status=0
+exit

tests/generic/414.out

@@ -0,0 +1,11 @@
+QA output created by 414
+Format and mount
+Create the original files
+Compare files
+de89461b64701958984c95d1bfb0065a  SCRATCH_MNT/test-414/file1
+de89461b64701958984c95d1bfb0065a  SCRATCH_MNT/test-414/file2
+Check extent counts
+Compare files after remounting
+de89461b64701958984c95d1bfb0065a  SCRATCH_MNT/test-414/file1
+de89461b64701958984c95d1bfb0065a  SCRATCH_MNT/test-414/file2
+Check extent counts

tests/generic/group

@@ -416,3 +416,4 @@
 411 auto quick mount
 412 auto quick metadata
 413 auto quick
+414 auto quick clone