#! /bin/bash
# FS QA Test No. btrfs/094
#
# Test that an incremental send issues valid clone operations for compressed
# file extents.
#
# For some compressed extents, namely those referred by a file extent item with
# a non-zero data offset, btrfs could issue a clone operation in the send stream
# with an offset and length pair that were not entirely contained in the source
# file's range, causing the receiving side to get -EINVAL errors from the clone
# ioctl when attempting to perform the clone operations.
#
# This issue was fixed by the following linux kernel btrfs patch:
#
#   Btrfs: incremental send, fix clone operations for 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()
{
	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
_require_cloner

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"

BLOCK_SIZE=$(get_block_size $SCRATCH_MNT)

# Create the file with a single extent of 32 blocks. This creates a metadata
# file extent item with a data start offset of 0 and a logical length of
# 32 blocks.
$XFS_IO_PROG -f -c "pwrite -S 0xaa $((16 * $BLOCK_SIZE)) $((32 * $BLOCK_SIZE))" \
	     -c "fsync" $SCRATCH_MNT/foo | _filter_xfs_io_blocks_modified

# Now rewrite the block range [16, 28[ of our file. This will make
# the inode's metadata continue to point to the single 32 block extent
# we created before, but now with an extent item that points to the
# extent with a data start offset referring to the 28th block and a
# logical length of 4 blocks.
# That metadata file extent item is associated with the block range
# [44, 48[.
$XFS_IO_PROG -c "pwrite -S 0xbb $((16 * $BLOCK_SIZE)) $((28 * $BLOCK_SIZE))" \
	     -c "fsync" $SCRATCH_MNT/foo | _filter_xfs_io_blocks_modified


# Now rewrite the block range [45, 48[. This will make the inode's
# metadata continue to point the 32 block extent we created earlier,
# with a single extent item that points to it with a start offset
# referring to the 28th block and a logical length of 1 block.
# That metadata file extent item is associated with the block range
# [44, 45[.
$XFS_IO_PROG -c "pwrite -S 0xcc $((45 * $BLOCK_SIZE)) $((3 * $BLOCK_SIZE))" \
	     -c "fsync" $SCRATCH_MNT/foo | _filter_xfs_io_blocks_modified

_run_btrfs_util_prog subvolume snapshot -r $SCRATCH_MNT $SCRATCH_MNT/mysnap1

# Now clone that same region of the 32 block extent into a new file, so that it
# gets referenced twice and the incremental send operation below decides to
# issue a clone operation instead of copying the data.
touch $SCRATCH_MNT/bar
$CLONER_PROG -s $((44 * $BLOCK_SIZE)) -d $((44 * $BLOCK_SIZE)) -l $BLOCK_SIZE \
	$SCRATCH_MNT/foo $SCRATCH_MNT/bar

_run_btrfs_util_prog subvolume snapshot -r $SCRATCH_MNT $SCRATCH_MNT/mysnap2

_run_btrfs_util_prog send $SCRATCH_MNT/mysnap1 -f $send_files_dir/1.snap
_run_btrfs_util_prog send -p $SCRATCH_MNT/mysnap1 $SCRATCH_MNT/mysnap2 \
	-f $send_files_dir/2.snap

echo "File contents in the original filesystem:"
echo "mysnap1/foo"
od -t x1 $SCRATCH_MNT/mysnap1/foo | _filter_od
echo "mysnap2/foo"
od -t x1 $SCRATCH_MNT/mysnap2/foo | _filter_od
echo "mysnap2/bar"
od -t x1 $SCRATCH_MNT/mysnap2/bar | _filter_od

# Now recreate the filesystem by receiving both send streams and verify we get
# the same file contents that the original filesystem had.
_scratch_unmount
_scratch_mkfs >>$seqres.full 2>&1
_scratch_mount

_run_btrfs_util_prog receive $SCRATCH_MNT -f $send_files_dir/1.snap
_run_btrfs_util_prog receive $SCRATCH_MNT -f $send_files_dir/2.snap

echo "File contents in the new filesystem:"
echo "mysnap1/foo"
od -t x1 $SCRATCH_MNT/mysnap1/foo | _filter_od
echo "mysnap2/foo"
od -t x1 $SCRATCH_MNT/mysnap2/foo | _filter_od
echo "mysnap2/bar"
od -t x1 $SCRATCH_MNT/mysnap2/bar | _filter_od

status=0
exit
