qemu/tests/qemu-iotests/154

458 lines
18 KiB
Plaintext
Raw Normal View History

#!/bin/bash
#
# qcow2 specific bdrv_pwrite_zeroes tests with backing files (complements 034)
#
qcow2: Optimize write zero of unaligned tail cluster We've already improved discards to operate efficiently on the tail of an unaligned qcow2 image; it's time to make a similar improvement to write zeroes. The special case is only valid at the tail cluster of a file, where we must recognize that any sectors beyond the image end would implicitly read as zero, and therefore should not penalize our logic for widening a partial cluster into writing the whole cluster as zero. However, note that for now, the special case of end-of-file is only recognized if there is no backing file, or if the backing file has the same length; that's because when the backing file is shorter than the active layer, we don't have code in place to recognize that reads of a sector unallocated at the top and beyond the backing end-of-file are implicitly zero. It's not much of a real loss, because most people don't use images that aren't cluster-aligned, or where the active layer is a different size than the backing layer (especially where the difference falls within a single cluster). Update test 154 to cover the new scenarios, using two images of intentionally differing length. While at it, fix the test to gracefully skip when run as ./check -qcow2 -o compat=0.10 154 since the older format lacks zero clusters already required earlier in the test. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: 20170507000552.20847-11-eblake@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-05-07 03:05:50 +03:00
# Copyright (C) 2016-2017 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 $seq"
here=`pwd`
status=1 # failure is the default!
_cleanup()
{
_cleanup_test_img
}
trap "_cleanup; exit \$status" 0 1 2 3 15
# get standard environment, filters and checks
. ./common.rc
. ./common.filter
_supported_fmt qcow2
_supported_proto file
_supported_os Linux
CLUSTER_SIZE=4k
qcow2: Optimize write zero of unaligned tail cluster We've already improved discards to operate efficiently on the tail of an unaligned qcow2 image; it's time to make a similar improvement to write zeroes. The special case is only valid at the tail cluster of a file, where we must recognize that any sectors beyond the image end would implicitly read as zero, and therefore should not penalize our logic for widening a partial cluster into writing the whole cluster as zero. However, note that for now, the special case of end-of-file is only recognized if there is no backing file, or if the backing file has the same length; that's because when the backing file is shorter than the active layer, we don't have code in place to recognize that reads of a sector unallocated at the top and beyond the backing end-of-file are implicitly zero. It's not much of a real loss, because most people don't use images that aren't cluster-aligned, or where the active layer is a different size than the backing layer (especially where the difference falls within a single cluster). Update test 154 to cover the new scenarios, using two images of intentionally differing length. While at it, fix the test to gracefully skip when run as ./check -qcow2 -o compat=0.10 154 since the older format lacks zero clusters already required earlier in the test. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: 20170507000552.20847-11-eblake@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-05-07 03:05:50 +03:00
size=$((128 * 1024 * 1024))
# This test requires zero clusters, added in v3 images
_unsupported_imgopts compat=0.10
echo
echo == backing file contains zeros ==
CLUSTER_SIZE=512 TEST_IMG="$TEST_IMG.base" _make_test_img $size
_make_test_img -b "$TEST_IMG.base"
# Make sure that the whole cluster is allocated even for partial write_zeroes
# when the backing file contains zeros
# X = non-zero data sector in backing file
# - = sector unallocated in whole backing chain
# 0 = sector touched by write_zeroes request
# 1. Tail unaligned: 00 00 -- --
# 2. Head unaligned: -- -- 00 00
# 3. Both unaligned: -- 00 00 --
# 4. Both, 2 clusters: -- -- -- 00 | 00 -- -- --
$QEMU_IO -c "write -z 0 2k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "write -z 10k 2k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "write -z 17k 2k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "write -z 27k 2k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
echo
echo == backing file contains non-zero data before write_zeroes ==
CLUSTER_SIZE=512 TEST_IMG="$TEST_IMG.base" _make_test_img $size
_make_test_img -b "$TEST_IMG.base"
# Single cluster; non-zero data at the cluster start
# ... | XX -- 00 -- | ...
$QEMU_IO -c "write -P 0x11 32k 1k" "$TEST_IMG.base" | _filter_qemu_io
$QEMU_IO -c "write -z 34k 1k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0x11 32k 1k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0 33k 3k" "$TEST_IMG" | _filter_qemu_io
# Single cluster; non-zero data exists, but not at the cluster start
# ... | -- XX 00 -- | ...
$QEMU_IO -c "write -P 0x11 65k 1k" "$TEST_IMG.base" | _filter_qemu_io
$QEMU_IO -c "write -z 66k 1k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0x11 65k 1k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0 64k 1k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0 66k 2k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
echo
echo == backing file contains non-zero data after write_zeroes ==
CLUSTER_SIZE=512 TEST_IMG="$TEST_IMG.base" _make_test_img $size
_make_test_img -b "$TEST_IMG.base"
# Single cluster; non-zero data directly after request
# ... | -- 00 XX -- | ...
$QEMU_IO -c "write -P 0x11 34k 1k" "$TEST_IMG.base" | _filter_qemu_io
$QEMU_IO -c "write -z 33k 1k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0 32k 2k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0x11 34k 1k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0 35k 1k" "$TEST_IMG" | _filter_qemu_io
# Single cluster; non-zero data exists, but not directly after request
# ... | -- 00 -- XX | ...
$QEMU_IO -c "write -P 0x11 43k 1k" "$TEST_IMG.base" | _filter_qemu_io
$QEMU_IO -c "write -z 41k 1k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0x11 43k 1k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0 40k 3k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
echo
echo == write_zeroes covers non-zero data ==
CLUSTER_SIZE=512 TEST_IMG="$TEST_IMG.base" _make_test_img $size
_make_test_img -b "$TEST_IMG.base"
# non-zero data at front of request
# Backing file: -- XX -- --
# Active layer: -- 00 00 --
$QEMU_IO -c "write -P 0x11 5k 1k" "$TEST_IMG.base" | _filter_qemu_io
$QEMU_IO -c "write -z 5k 2k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0 4k 4k" "$TEST_IMG" | _filter_qemu_io
# non-zero data at end of request
# Backing file: -- -- XX --
# Active layer: -- 00 00 --
$QEMU_IO -c "write -P 0x11 14k 1k" "$TEST_IMG.base" | _filter_qemu_io
$QEMU_IO -c "write -z 13k 2k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0 12k 4k" "$TEST_IMG" | _filter_qemu_io
# non-zero data matches size of request
# Backing file: -- XX XX --
# Active layer: -- 00 00 --
$QEMU_IO -c "write -P 0x11 21k 2k" "$TEST_IMG.base" | _filter_qemu_io
$QEMU_IO -c "write -z 21k 2k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0 20k 4k" "$TEST_IMG" | _filter_qemu_io
# non-zero data smaller than request
# Backing file: -- -X X- --
# Active layer: -- 00 00 --
$QEMU_IO -c "write -P 0x11 30208 1k" "$TEST_IMG.base" | _filter_qemu_io
$QEMU_IO -c "write -z 29k 2k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0 28k 4k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
echo
echo == spanning two clusters, non-zero before request ==
CLUSTER_SIZE=512 TEST_IMG="$TEST_IMG.base" _make_test_img $size
_make_test_img -b "$TEST_IMG.base"
# Two clusters; non-zero data before request:
# 1. At cluster start: 32k: XX -- -- 00 | 00 -- -- --
# 2. Between unallocated space: 48k: -- XX -- 00 | 00 -- -- --
# 3. Directly before request: 64k: -- -- XX 00 | 00 -- -- --
$QEMU_IO -c "write -P 0x11 32k 1k" "$TEST_IMG.base" | _filter_qemu_io
$QEMU_IO -c "write -z 35k 2k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0x11 32k 1k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0 33k 7k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "write -P 0x11 49k 1k" "$TEST_IMG.base" | _filter_qemu_io
$QEMU_IO -c "write -z 51k 2k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0 48k 1k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0x11 49k 1k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0 50k 6k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "write -P 0x11 66k 1k" "$TEST_IMG.base" | _filter_qemu_io
$QEMU_IO -c "write -z 67k 2k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0 64k 2k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0x11 66k 1k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0 67k 5k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
echo
echo == spanning two clusters, non-zero after request ==
CLUSTER_SIZE=512 TEST_IMG="$TEST_IMG.base" _make_test_img $size
_make_test_img -b "$TEST_IMG.base"
# Two clusters; non-zero data after request:
# 1. Directly after request: 32k: -- -- -- 00 | 00 XX -- --
# 2. Between unallocated space: 48k: -- -- -- 00 | 00 -- XX --
# 3. At cluster end: 64k: -- -- -- 00 | 00 -- -- XX
$QEMU_IO -c "write -P 0x11 37k 1k" "$TEST_IMG.base" | _filter_qemu_io
$QEMU_IO -c "write -z 35k 2k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0 32k 5k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0x11 37k 1k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0 38k 2k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "write -P 0x11 54k 1k" "$TEST_IMG.base" | _filter_qemu_io
$QEMU_IO -c "write -z 51k 2k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0 48k 6k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0x11 54k 1k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0 55k 1k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "write -P 0x11 71k 1k" "$TEST_IMG.base" | _filter_qemu_io
$QEMU_IO -c "write -z 67k 2k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0 64k 7k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0x11 71k 1k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
echo
echo == spanning two clusters, partially overwriting backing file ==
CLUSTER_SIZE=512 TEST_IMG="$TEST_IMG.base" _make_test_img $size
_make_test_img -b "$TEST_IMG.base"
# Backing file: -- -- XX XX | XX XX -- --
# Active layer: -- -- XX 00 | 00 XX -- --
$QEMU_IO -c "write -P 0x11 2k 4k" "$TEST_IMG.base" | _filter_qemu_io
$QEMU_IO -c "write -z 3k 2k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0 0k 2k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0x11 2k 1k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0 3k 2k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0x11 5k 1k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0 6k 2k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
echo
echo == spanning multiple clusters, non-zero in first cluster ==
CLUSTER_SIZE=512 TEST_IMG="$TEST_IMG.base" _make_test_img $size
_make_test_img -b "$TEST_IMG.base"
# Backing file: 64k: XX XX -- -- | -- -- -- -- | -- -- -- --
# Active layer: 64k: XX XX 00 00 | 00 00 00 00 | 00 -- -- --
$QEMU_IO -c "write -P 0x11 64k 2k" "$TEST_IMG.base" | _filter_qemu_io
$QEMU_IO -c "write -z 66k 7k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0x11 64k 2k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0 66k 10k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
echo
echo == spanning multiple clusters, non-zero in intermediate cluster ==
CLUSTER_SIZE=512 TEST_IMG="$TEST_IMG.base" _make_test_img $size
_make_test_img -b "$TEST_IMG.base"
# Backing file: 64k: -- -- -- -- | -- XX XX -- | -- -- -- --
# Active layer: 64k: -- -- 00 00 | 00 00 00 00 | 00 -- -- --
$QEMU_IO -c "write -P 0x11 69k 2k" "$TEST_IMG.base" | _filter_qemu_io
$QEMU_IO -c "write -z 66k 7k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0 64k 12k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
echo
echo == spanning multiple clusters, non-zero in final cluster ==
CLUSTER_SIZE=512 TEST_IMG="$TEST_IMG.base" _make_test_img $size
_make_test_img -b "$TEST_IMG.base"
# Backing file: 64k: -- -- -- -- | -- -- -- -- | -- -- XX XX
# Active layer: 64k: -- -- 00 00 | 00 00 00 00 | 00 -- XX XX
$QEMU_IO -c "write -P 0x11 74k 2k" "$TEST_IMG.base" | _filter_qemu_io
$QEMU_IO -c "write -z 66k 7k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0 64k 10k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0x11 74k 2k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
echo
echo == spanning multiple clusters, partially overwriting backing file ==
CLUSTER_SIZE=512 TEST_IMG="$TEST_IMG.base" _make_test_img $size
_make_test_img -b "$TEST_IMG.base"
# Backing file: 64k: -- XX XX XX | XX XX XX XX | XX XX XX --
# Active layer: 64k: -- XX 00 00 | 00 00 00 00 | 00 XX XX --
$QEMU_IO -c "write -P 0x11 65k 10k" "$TEST_IMG.base" | _filter_qemu_io
$QEMU_IO -c "write -z 66k 7k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0 64k 1k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0x11 65k 1k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0 66k 7k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0x11 73k 2k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0 75k 1k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
qcow2: Optimize write zero of unaligned tail cluster We've already improved discards to operate efficiently on the tail of an unaligned qcow2 image; it's time to make a similar improvement to write zeroes. The special case is only valid at the tail cluster of a file, where we must recognize that any sectors beyond the image end would implicitly read as zero, and therefore should not penalize our logic for widening a partial cluster into writing the whole cluster as zero. However, note that for now, the special case of end-of-file is only recognized if there is no backing file, or if the backing file has the same length; that's because when the backing file is shorter than the active layer, we don't have code in place to recognize that reads of a sector unallocated at the top and beyond the backing end-of-file are implicitly zero. It's not much of a real loss, because most people don't use images that aren't cluster-aligned, or where the active layer is a different size than the backing layer (especially where the difference falls within a single cluster). Update test 154 to cover the new scenarios, using two images of intentionally differing length. While at it, fix the test to gracefully skip when run as ./check -qcow2 -o compat=0.10 154 since the older format lacks zero clusters already required earlier in the test. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: 20170507000552.20847-11-eblake@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-05-07 03:05:50 +03:00
echo
echo == unaligned image tail cluster, no allocation needed ==
# With no backing file, write to all or part of unallocated partial cluster
# will mark the cluster as zero, but does not allocate.
# Re-create the image each time to get back to unallocated clusters.
# Write at the front: sector-wise, the request is: 128m... | 00 -- -- --
_make_test_img $((size + 2048))
$QEMU_IO -c "write -z $size 512" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "alloc $size 2048" "$TEST_IMG" | _filter_qemu_io
$QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
# Write at the back: sector-wise, the request is: 128m... | -- -- -- 00
_make_test_img $((size + 2048))
$QEMU_IO -c "write -z $((size + 1536)) 512" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "alloc $size 2048" "$TEST_IMG" | _filter_qemu_io
$QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
# Write at middle: sector-wise, the request is: 128m... | -- 00 00 --
_make_test_img $((size + 2048))
$QEMU_IO -c "write -z $((size + 512)) 1024" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "alloc $size 2048" "$TEST_IMG" | _filter_qemu_io
$QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
# Write entire cluster: sector-wise, the request is: 128m... | 00 00 00 00
_make_test_img $((size + 2048))
$QEMU_IO -c "write -z $size 2048" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "alloc $size 2048" "$TEST_IMG" | _filter_qemu_io
$QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
# Repeat with backing file holding unallocated cluster.
CLUSTER_SIZE=2048 TEST_IMG="$TEST_IMG.base" _make_test_img $((size + 1024))
# Write at the front: sector-wise, the request is:
# backing: 128m... | -- --
# active: 128m... | 00 -- -- --
_make_test_img -b "$TEST_IMG.base" $((size + 2048))
$QEMU_IO -c "write -z $size 512" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "alloc $size 2048" "$TEST_IMG" | _filter_qemu_io
$QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
# Write at the back: sector-wise, the request is:
# backing: 128m... | -- --
# active: 128m... | -- -- -- 00
_make_test_img -b "$TEST_IMG.base" $((size + 2048))
$QEMU_IO -c "write -z $((size + 1536)) 512" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "alloc $size 2048" "$TEST_IMG" | _filter_qemu_io
$QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
# Write at middle: sector-wise, the request is:
# backing: 128m... | -- --
# active: 128m... | -- 00 00 --
_make_test_img -b "$TEST_IMG.base" $((size + 2048))
$QEMU_IO -c "write -z $((size + 512)) 1024" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "alloc $size 2048" "$TEST_IMG" | _filter_qemu_io
$QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
# Write entire cluster: sector-wise, the request is:
# backing: 128m... | -- --
# active: 128m... | 00 00 00 00
_make_test_img -b "$TEST_IMG.base" $((size + 2048))
$QEMU_IO -c "write -z $size 2048" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "alloc $size 2048" "$TEST_IMG" | _filter_qemu_io
$QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
# Repeat with backing file holding zero'd cluster
$QEMU_IO -c "write -z $size 512" "$TEST_IMG.base" | _filter_qemu_io
# Write at the front: sector-wise, the request is:
# backing: 128m... | 00 00
# active: 128m... | 00 -- -- --
_make_test_img -b "$TEST_IMG.base" $((size + 2048))
$QEMU_IO -c "write -z $size 512" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "alloc $size 2048" "$TEST_IMG" | _filter_qemu_io
$QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
# Write at the back: sector-wise, the request is:
# backing: 128m... | 00 00
# active: 128m... | -- -- -- 00
_make_test_img -b "$TEST_IMG.base" $((size + 2048))
$QEMU_IO -c "write -z $((size + 1536)) 512" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "alloc $size 2048" "$TEST_IMG" | _filter_qemu_io
$QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
# Write at middle: sector-wise, the request is:
# backing: 128m... | 00 00
# active: 128m... | -- 00 00 --
_make_test_img -b "$TEST_IMG.base" $((size + 2048))
$QEMU_IO -c "write -z $((size + 512)) 1024" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "alloc $size 2048" "$TEST_IMG" | _filter_qemu_io
$QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
# Write entire cluster: sector-wise, the request is:
# backing: 128m... | 00 00
# active: 128m... | 00 00 00 00
_make_test_img -b "$TEST_IMG.base" $((size + 2048))
$QEMU_IO -c "write -z $size 2048" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "alloc $size 2048" "$TEST_IMG" | _filter_qemu_io
$QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
# A preallocated cluster maintains its allocation, whether it stays as
# data due to a partial write:
# Convert 128m... | XX XX => ... | XX 00
_make_test_img $((size + 1024))
$QEMU_IO -c "write -P 1 $((size)) 1024" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "write -z $((size + 512)) 512" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 1 $((size)) 512" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0 $((size + 512)) 512" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "alloc $size 1024" "$TEST_IMG" | _filter_qemu_io
$QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
# or because it is the entire cluster and can use the zero flag:
# Convert 128m... | XX XX => ... | 00 00
$QEMU_IO -c "write -z $((size)) 1024" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "alloc $size 1024" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0 $size 1024" "$TEST_IMG" | _filter_qemu_io
$QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
echo
echo == unaligned image tail cluster, allocation required ==
# Write beyond backing file must COW
# Backing file: 128m... | XX --
# Active layer: 128m... | -- -- 00 --
CLUSTER_SIZE=512 TEST_IMG="$TEST_IMG.base" _make_test_img $((size + 1024))
_make_test_img -b "$TEST_IMG.base" $((size + 2048))
$QEMU_IO -c "write -P 1 $((size)) 512" "$TEST_IMG.base" | _filter_qemu_io
$QEMU_IO -c "write -z $((size + 1024)) 512" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 1 $((size)) 512" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0 $((size + 512)) 1536" "$TEST_IMG" | _filter_qemu_io
$QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
# Writes at boundaries of (partial) cluster must not lose mid-cluster data
# Backing file: 128m: ... | -- XX
# Active layer: 128m: ... | 00 -- -- 00
CLUSTER_SIZE=512 TEST_IMG="$TEST_IMG.base" _make_test_img $((size + 1024))
_make_test_img -b "$TEST_IMG.base" $((size + 2048))
$QEMU_IO -c "write -P 1 $((size + 512)) 512" "$TEST_IMG.base" | _filter_qemu_io
$QEMU_IO -c "write -z $((size)) 512" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0 $((size)) 512" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 1 $((size + 512)) 512" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0 $((size + 1024)) 1024" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "write -z $((size + 1536)) 512" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0 $((size)) 512" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 1 $((size + 512)) 512" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0 $((size + 1024)) 1024" "$TEST_IMG" | _filter_qemu_io
$QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
# success, all done
echo "*** done"
rm -f $seq.full
status=0