Hi Darrick
At 02/25/2017 09:12 AM, Darrick J. Wong wrote:
From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
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?
Btrfs can't pass the test since it doesn't merge such mapping, not only
the fiemap result, but also on-disk extents.
IIRC ocfs also merges it, so I wonder if this is a documented behavior
to merge any extent maps that are adjacent.
Further more, if a fs has a limit on extent size on disk, e.g 128M.
But 2 file extents are also adjacent on disk, then should fiemap return
a large 256M map or just 2 adjacent 128M maps?
Thanks,
Qu
Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
---
tests/generic/930 | 106 +++++++++++++++++++++++++++++++++++++++++++++++++
tests/generic/930.out | 11 +++++
tests/generic/group | 1
3 files changed, 118 insertions(+)
create mode 100755 tests/generic/930
create mode 100644 tests/generic/930.out
diff --git a/tests/generic/930 b/tests/generic/930
new file mode 100755
index 0000000..15d8cbf
--- /dev/null
+++ b/tests/generic/930
@@ -0,0 +1,106 @@
+#! /bin/bash
+# FS QA Test No. 930
+#
+# 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
diff --git a/tests/generic/930.out b/tests/generic/930.out
new file mode 100644
index 0000000..556108a
--- /dev/null
+++ b/tests/generic/930.out
@@ -0,0 +1,11 @@
+QA output created by 930
+Format and mount
+Create the original files
+Compare files
+de89461b64701958984c95d1bfb0065a SCRATCH_MNT/test-930/file1
+de89461b64701958984c95d1bfb0065a SCRATCH_MNT/test-930/file2
+Check extent counts
+Compare files after remounting
+de89461b64701958984c95d1bfb0065a SCRATCH_MNT/test-930/file1
+de89461b64701958984c95d1bfb0065a SCRATCH_MNT/test-930/file2
+Check extent counts
diff --git a/tests/generic/group b/tests/generic/group
index d0bc47d..4b4df66 100644
--- a/tests/generic/group
+++ b/tests/generic/group
@@ -411,3 +411,4 @@
406 auto quick dangerous
407 auto quick clone metadata
408 auto quick clone dedupe metadata
+930 auto quick clone
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