btrfs: send with shared and compressed extents

Test that a send operation works correctly with reflinked files (cloned
extents which multiple files point to) that have compressed extents.

This used to fail on btrfs, resulting in different file digests after
receiving the send stream, and got fixed by the linux kernel patch
titled:

  "Btrfs: send, fix file corruption due to incorrect cloning operations"

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
This commit is contained in:
Filipe Manana
2015-10-14 14:19:34 +11:00
committed by Dave Chinner
parent f1b304ab97
commit 71d8215c19
3 changed files with 125 additions and 0 deletions
+111
View File
@@ -0,0 +1,111 @@
#! /bin/bash
# FS QA Test No. btrfs/109
#
# Test that a send operation works correctly with reflinked files (cloned
# extents which multiple files point to) that have compressed extents.
#
#-----------------------------------------------------------------------
# Copyright (C) 2015 SUSE Linux Products GmbH. All Rights Reserved.
# Author: Filipe Manana <fdmanana@suse.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 -fr $send_files_dir
rm -f $tmp.*
}
# get standard environment, filters and checks
. ./common/rc
. ./common/filter
# real QA test starts here
_supported_fs btrfs
_supported_os Linux
_require_scratch
_need_to_be_root
_require_cp_reflink
send_files_dir=$TEST_DIR/btrfs-test-$seq
rm -f $seqres.full
rm -fr $send_files_dir
mkdir $send_files_dir
_scratch_mkfs >>$seqres.full 2>&1
_scratch_mount "-o compress"
# Create our file with an extent of 100K starting at file offset 0K.
$XFS_IO_PROG -f -c "pwrite -S 0xaa 0K 100K" \
-c "fsync" \
$SCRATCH_MNT/foo | _filter_xfs_io
# Rewrite part of the previous extent (its first 40K) and write a new 100K
# extent starting at file offset 100K.
$XFS_IO_PROG -c "pwrite -S 0xbb 0K 40K" \
-c "pwrite -S 0xcc 100K 100K" \
$SCRATCH_MNT/foo | _filter_xfs_io
# Our file foo now has 3 file extent items in its metadata:
#
# 1) One covering the file range 0 to 40K;
# 2) One covering the file range 40K to 100K, which points to the first extent
# we wrote to the file and has a data offset field with value 40K (our file
# no longer uses the first 40K of data from that extent);
# 3) One covering the file range 100K to 200K.
# Now clone our file foo into file bar.
cp --reflink=always $SCRATCH_MNT/foo $SCRATCH_MNT/bar
# Create our snapshot for the send operation.
_run_btrfs_util_prog subvolume snapshot -r $SCRATCH_MNT $SCRATCH_MNT/snap
echo "File digests in the original filesystem:"
md5sum $SCRATCH_MNT/snap/foo | _filter_scratch
md5sum $SCRATCH_MNT/snap/bar | _filter_scratch
_run_btrfs_util_prog send $SCRATCH_MNT/snap -f $send_files_dir/1.snap
# Now recreate the filesystem by receiving the send stream and verify we get
# the same file contents that the original filesystem had.
# Btrfs send used to issue a clone operation from foo's range [80K, 140K[ to
# bar's range [40K, 100K[ when cloning the extent pointed to by foo's second
# file extent item, this was incorrect because of bad accounting of the file
# extent item's data offset field. The correct range to clone from should have
# been [40K, 100K[.
_scratch_unmount
_scratch_mkfs >>$seqres.full 2>&1
_scratch_mount "-o compress"
_run_btrfs_util_prog receive $SCRATCH_MNT -f $send_files_dir/1.snap
echo "File digests in the new filesystem:"
# Must match the digests we got in the original filesystem.
md5sum $SCRATCH_MNT/snap/foo | _filter_scratch
md5sum $SCRATCH_MNT/snap/bar | _filter_scratch
status=0
exit