tests/qemu-iotests/253

#!/usr/bin/env bash
#
# Test qemu-img vs. unaligned images; O_DIRECT version
# (Originates from 221)
#
# Copyright (C) 2019 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/>.
#

seq="$(basename $0)"
echo "QA output created by $seq"

status=1 # failure is the default!

_cleanup()
{
    _cleanup_test_img
}
trap "_cleanup; exit \$status" 0 1 2 3 15

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

_supported_fmt raw
_supported_proto file
_supported_os Linux

_default_cache_mode none
_supported_cache_modes none directsync

echo
echo "=== Check mapping of unaligned raw image ==="
echo

# We do not know how large a physical sector is, but it is certainly
# going to be a factor of 1 MB
size=$((1 * 1024 * 1024 - 1))

# qemu-img create rounds size up to BDRV_SECTOR_SIZE
_make_test_img $size
$QEMU_IMG map --output=json --image-opts \
    "driver=$IMGFMT,file.driver=file,file.filename=$TEST_IMG,cache.direct=on" \
    | _filter_qemu_img_map

# so we resize it and check again
truncate --size=$size "$TEST_IMG"
$QEMU_IMG map --output=json --image-opts \
    "driver=$IMGFMT,file.driver=file,file.filename=$TEST_IMG,cache.direct=on" \
    | _filter_qemu_img_map

# qemu-io with O_DIRECT always writes whole physical sectors.  Again,
# we do not know how large a physical sector is, so we just start
# writing from a 64 kB boundary, which should always be aligned.
offset=$((1 * 1024 * 1024 - 64 * 1024))
$QEMU_IO -c "w $offset $((size - offset))" "$TEST_IMG" | _filter_qemu_io
$QEMU_IMG map --output=json --image-opts \
    "driver=$IMGFMT,file.driver=file,file.filename=$TEST_IMG,cache.direct=on" \
    | _filter_qemu_img_map

# Resize it and check again -- contrary to 221, we may not get partial
# sectors here, so there should be only two areas (one zero, one
# data).
truncate --size=$size "$TEST_IMG"
$QEMU_IMG map --output=json --image-opts \
    "driver=$IMGFMT,file.driver=file,file.filename=$TEST_IMG,cache.direct=on" \
    | _filter_qemu_img_map

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