tests/qemu-iotests/024

#!/usr/bin/env bash
# group: rw backing auto quick
#
# Rebasing COW images
#
# Copyright (C) 2009 Red Hat, Inc.
#
# 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; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will 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, see <http://www.gnu.org/licenses/>.
#

# creator
owner=kwolf@redhat.com

seq=`basename $0`
echo "QA output created by $seq"

status=1	# failure is the default!

_cleanup()
{
    _cleanup_test_img
    _rm_test_img "$TEST_DIR/t.$IMGFMT.base_old"
    _rm_test_img "$TEST_DIR/t.$IMGFMT.base_new"

    _rm_test_img "$TEST_DIR/subdir/t.$IMGFMT"
    _rm_test_img "$TEST_DIR/subdir/t.$IMGFMT.base_old"
    _rm_test_img "$TEST_DIR/subdir/t.$IMGFMT.base_new"
    rmdir "$TEST_DIR/subdir" 2> /dev/null
}
trap "_cleanup; exit \$status" 0 1 2 3 15

# get standard environment, filters and checks
. ./common.rc
. ./common.filter
. ./common.pattern

# Currently only qcow2 and qed support rebasing
_supported_fmt qcow2 qed
_supported_proto file
_supported_os Linux

CLUSTER_SIZE=65536

# Cluster allocations to be tested:
#
# Backing (old) 11  --  11  --  11  --  11  --
# Backing (new) 22  22  --  --  22  22  --  --
# COW image     33  33  33  33  --  --  --  --
#
# The pattern is written twice to have both an alloc -> non-alloc and a
# non-alloc -> alloc transition in the COW image.

echo "Creating backing file"
echo

TEST_IMG_SAVE="$TEST_IMG"
TEST_IMG="$TEST_IMG.base_old"

_make_test_img 1G
io_pattern writev 0 $CLUSTER_SIZE $((2 * CLUSTER_SIZE)) 8 0x11

TEST_IMG="$TEST_IMG_SAVE.base_new"

echo "Creating new backing file"
echo

_make_test_img 1G
io_pattern writev 0 $((2 * CLUSTER_SIZE)) $((4 * CLUSTER_SIZE)) 4 0x22


TEST_IMG="$TEST_IMG_SAVE"

echo "Creating COW image"
echo

_make_test_img -b "$TEST_IMG.base_old" -F $IMGFMT 1G
io_pattern writev 0 $((4 * CLUSTER_SIZE)) 0 1 0x33
io_pattern writev $((8 * CLUSTER_SIZE)) $((4 * CLUSTER_SIZE)) 0 1 0x33

echo "Read before the rebase to make sure everything is set up correctly"
echo
io_pattern readv $((0 * CLUSTER_SIZE)) $CLUSTER_SIZE 0 1 0x33
io_pattern readv $((1 * CLUSTER_SIZE)) $CLUSTER_SIZE 0 1 0x33
io_pattern readv $((2 * CLUSTER_SIZE)) $CLUSTER_SIZE 0 1 0x33
io_pattern readv $((3 * CLUSTER_SIZE)) $CLUSTER_SIZE 0 1 0x33
io_pattern readv $((4 * CLUSTER_SIZE)) $CLUSTER_SIZE 0 1 0x11
io_pattern readv $((5 * CLUSTER_SIZE)) $CLUSTER_SIZE 0 1 0x00
io_pattern readv $((6 * CLUSTER_SIZE)) $CLUSTER_SIZE 0 1 0x11
io_pattern readv $((7 * CLUSTER_SIZE)) $CLUSTER_SIZE 0 1 0x00
io_pattern readv $((8 * CLUSTER_SIZE)) $CLUSTER_SIZE 0 1 0x33
io_pattern readv $((9 * CLUSTER_SIZE)) $CLUSTER_SIZE 0 1 0x33
io_pattern readv $((10 * CLUSTER_SIZE)) $CLUSTER_SIZE 0 1 0x33
io_pattern readv $((11 * CLUSTER_SIZE)) $CLUSTER_SIZE 0 1 0x33
io_pattern readv $((12 * CLUSTER_SIZE)) $CLUSTER_SIZE 0 1 0x11
io_pattern readv $((13 * CLUSTER_SIZE)) $CLUSTER_SIZE 0 1 0x00
io_pattern readv $((14 * CLUSTER_SIZE)) $CLUSTER_SIZE 0 1 0x11
io_pattern readv $((15 * CLUSTER_SIZE)) $CLUSTER_SIZE 0 1 0x00

echo
echo Rebase and test again
echo
$QEMU_IMG rebase -b "$TEST_IMG.base_new" -F $IMGFMT "$TEST_IMG"
io_pattern readv $((0 * CLUSTER_SIZE)) $CLUSTER_SIZE 0 1 0x33
io_pattern readv $((1 * CLUSTER_SIZE)) $CLUSTER_SIZE 0 1 0x33
io_pattern readv $((2 * CLUSTER_SIZE)) $CLUSTER_SIZE 0 1 0x33
io_pattern readv $((3 * CLUSTER_SIZE)) $CLUSTER_SIZE 0 1 0x33
io_pattern readv $((4 * CLUSTER_SIZE)) $CLUSTER_SIZE 0 1 0x11
io_pattern readv $((5 * CLUSTER_SIZE)) $CLUSTER_SIZE 0 1 0x00
io_pattern readv $((6 * CLUSTER_SIZE)) $CLUSTER_SIZE 0 1 0x11
io_pattern readv $((7 * CLUSTER_SIZE)) $CLUSTER_SIZE 0 1 0x00
io_pattern readv $((8 * CLUSTER_SIZE)) $CLUSTER_SIZE 0 1 0x33
io_pattern readv $((9 * CLUSTER_SIZE)) $CLUSTER_SIZE 0 1 0x33
io_pattern readv $((10 * CLUSTER_SIZE)) $CLUSTER_SIZE 0 1 0x33
io_pattern readv $((11 * CLUSTER_SIZE)) $CLUSTER_SIZE 0 1 0x33
io_pattern readv $((12 * CLUSTER_SIZE)) $CLUSTER_SIZE 0 1 0x11
io_pattern readv $((13 * CLUSTER_SIZE)) $CLUSTER_SIZE 0 1 0x00
io_pattern readv $((14 * CLUSTER_SIZE)) $CLUSTER_SIZE 0 1 0x11
io_pattern readv $((15 * CLUSTER_SIZE)) $CLUSTER_SIZE 0 1 0x00

echo
echo "=== Test rebase in a subdirectory of the working directory ==="
echo

# Clean up the old images beforehand so they do not interfere with
# this test
_cleanup

mkdir "$TEST_DIR/subdir"

# Relative to the overlay
BASE_OLD_OREL="t.$IMGFMT.base_old"
BASE_NEW_OREL="t.$IMGFMT.base_new"

# Relative to $TEST_DIR (which is going to be our working directory)
OVERLAY_WREL="subdir/t.$IMGFMT"

BASE_OLD="$TEST_DIR/subdir/$BASE_OLD_OREL"
BASE_NEW="$TEST_DIR/subdir/$BASE_NEW_OREL"
OVERLAY="$TEST_DIR/$OVERLAY_WREL"

# Test done here:
#
# Backing (old): 11 11 -- 11
# Backing (new): -- 22 22 11
# Overlay:       -- -- -- --
#
# Rebasing works, we have verified that above.  Here, we just want to
# see that rebasing is done for the correct target backing file.

TEST_IMG=$BASE_OLD _make_test_img 1M
TEST_IMG=$BASE_NEW _make_test_img 1M
TEST_IMG=$OVERLAY _make_test_img -b "$BASE_OLD_OREL" -F $IMGFMT 1M

echo

$QEMU_IO "$BASE_OLD" \
    -c "write -P 0x11 $((0 * CLUSTER_SIZE)) $((2 * CLUSTER_SIZE))" \
    -c "write -P 0x11 $((3 * CLUSTER_SIZE)) $((1 * CLUSTER_SIZE))" \
    | _filter_qemu_io

$QEMU_IO "$BASE_NEW" \
    -c "write -P 0x22 $((1 * CLUSTER_SIZE)) $((2 * CLUSTER_SIZE))" \
    -c "write -P 0x11 $((3 * CLUSTER_SIZE)) $((1 * CLUSTER_SIZE))" \
    | _filter_qemu_io

echo

pushd "$TEST_DIR" >/dev/null
$QEMU_IMG rebase -f "$IMGFMT" -b "$BASE_NEW_OREL" -F $IMGFMT "$OVERLAY_WREL"
popd >/dev/null

# Verify the backing path is correct
TEST_IMG=$OVERLAY _img_info | grep '^backing file:'

echo

# Verify the data is correct
$QEMU_IO "$OVERLAY" \
    -c "read -P 0x11 $((0 * CLUSTER_SIZE)) $CLUSTER_SIZE" \
    -c "read -P 0x11 $((1 * CLUSTER_SIZE)) $CLUSTER_SIZE" \
    -c "read -P 0x00 $((2 * CLUSTER_SIZE)) $CLUSTER_SIZE" \
    -c "read -P 0x11 $((3 * CLUSTER_SIZE)) $CLUSTER_SIZE" \
    | _filter_qemu_io

echo

# Verify that cluster #3 is not allocated (because it is the same in
# $BASE_OLD and $BASE_NEW)
$QEMU_IMG map "$OVERLAY" | _filter_qemu_img_map

# Check that rebase within the chain is working when
# overlay_size > old_backing_size
#
# base_new <-- base_old <-- overlay
#
# Backing (new): 11 11 11 11 11
# Backing (old): 22 22 22 22
# Overlay:       -- -- -- -- --
#
# As a result, overlay should contain data identical to base_old, with the
# last cluster remaining unallocated.

echo
echo "=== Test rebase within one backing chain ==="
echo

echo "Creating backing chain"
echo

TEST_IMG=$BASE_NEW _make_test_img $(( CLUSTER_SIZE * 5 ))
TEST_IMG=$BASE_OLD _make_test_img -b "$BASE_NEW" -F $IMGFMT \
    $(( CLUSTER_SIZE * 4 ))
TEST_IMG=$OVERLAY _make_test_img -b "$BASE_OLD" -F $IMGFMT \
    $(( CLUSTER_SIZE * 5 ))

echo
echo "Fill backing files with data"
echo

$QEMU_IO "$BASE_NEW" -c "write -P 0x11 0 $(( CLUSTER_SIZE * 5 ))" \
    | _filter_qemu_io
$QEMU_IO "$BASE_OLD" -c "write -P 0x22 0 $(( CLUSTER_SIZE * 4 ))" \
    | _filter_qemu_io

echo
echo "Check the last cluster is zeroed in overlay before the rebase"
echo
$QEMU_IO "$OVERLAY" -c "read -P 0x00 $(( CLUSTER_SIZE * 4 )) $CLUSTER_SIZE" \
    | _filter_qemu_io

echo
echo "Rebase onto another image in the same chain"
echo

$QEMU_IMG rebase -b "$BASE_NEW" -F $IMGFMT "$OVERLAY"

echo "Verify that data is read the same before and after rebase"
echo

# Verify the first 4 clusters are still read the same as in the old base
$QEMU_IO "$OVERLAY" -c "read -P 0x22 0 $(( CLUSTER_SIZE * 4 ))" \
    | _filter_qemu_io
# Verify the last cluster still reads as zeroes
$QEMU_IO "$OVERLAY" -c "read -P 0x00 $(( CLUSTER_SIZE * 4 )) $CLUSTER_SIZE" \
    | _filter_qemu_io

echo

# success, all done
echo "*** done"
rm -f $seq.full
status=0