iotests: Add test 179 to cover write zeroes with unmap

No tests were covering write zeroes with unmap.  Additionally,
I needed to prove that my previous patches for correct status
reporting and write zeroes optimizations actually had an impact.

The test works for cluster_size between 8k and 2M (for smaller
sizes, it fails because our allocation patterns are not contiguous
with small clusters - in part, the largest consecutive allocation
we tend to get is often bounded by the size covered by one L2
table).

Note that testing for zero clusters is tricky: 'qemu-io map'
reports whether data comes from the current layer of the image
(useful for sniffing out which regions of the file have
QCOW_OFLAG_ZERO) - but doesn't show which clusters have mappings;
while 'qemu-img map' sees "zero":true for both unallocated and
zero clusters for any qcow2 with no backing layer (so less useful
at detecting true zero clusters), but reliably shows mappings.
So we have to rely on both queries side-by-side at each point of
the test.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20170507000552.20847-10-eblake@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
This commit is contained in:
Eric Blake 2017-05-06 19:05:49 -05:00 committed by Max Reitz
parent d9ca2214bd
commit e249d51952
3 changed files with 287 additions and 0 deletions

130
tests/qemu-iotests/179 Executable file
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@ -0,0 +1,130 @@
#!/bin/bash
#
# Test case for write zeroes with unmap
#
# Copyright (C) 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=eblake@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
# v2 images can't mark clusters as zero
_unsupported_imgopts compat=0.10
echo
echo '=== Testing write zeroes with unmap ==='
echo
TEST_IMG="$TEST_IMG.base" _make_test_img 64M
_make_test_img -b "$TEST_IMG.base"
# Offsets chosen at or near 2M boundaries so test works at all cluster sizes
# 8k and larger (smaller clusters fail due to non-contiguous allocations)
# Aligned writes to unallocated cluster should not allocate mapping, but must
# mark cluster as zero, whether or not unmap was requested
$QEMU_IO -c "write -z -u 2M 2M" "$TEST_IMG.base" | _filter_qemu_io
$QEMU_IO -c "write -z 6M 2M" "$TEST_IMG.base" | _filter_qemu_io
$QEMU_IO -c "map" "$TEST_IMG.base" | _filter_qemu_io
$QEMU_IMG map --output=json "$TEST_IMG.base" | _filter_qemu_img_map
# Unaligned writes need not allocate mapping if the cluster already reads
# as zero, but must mark cluster as zero, whether or not unmap was requested
$QEMU_IO -c "write -z -u 10485761 2097150" "$TEST_IMG.base" | _filter_qemu_io
$QEMU_IO -c "write -z 14680065 2097150" "$TEST_IMG.base" | _filter_qemu_io
$QEMU_IO -c "map" "$TEST_IMG.base" | _filter_qemu_io
$QEMU_IMG map --output=json "$TEST_IMG.base" | _filter_qemu_img_map
# Requesting unmap of normal data must deallocate; omitting unmap should
# preserve the mapping
$QEMU_IO -c "write 18M 14M" "$TEST_IMG.base" | _filter_qemu_io
$QEMU_IO -c "write -z -u 20M 2M" "$TEST_IMG.base" | _filter_qemu_io
$QEMU_IO -c "write -z 24M 6M" "$TEST_IMG.base" | _filter_qemu_io
$QEMU_IO -c "map" "$TEST_IMG.base" | _filter_qemu_io
$QEMU_IMG map --output=json "$TEST_IMG.base" | _filter_qemu_img_map
# Likewise when writing on already-mapped zero data
$QEMU_IO -c "write -z -u 26M 2M" "$TEST_IMG.base" | _filter_qemu_io
$QEMU_IO -c "write -z 28M 2M" "$TEST_IMG.base" | _filter_qemu_io
$QEMU_IO -c "map" "$TEST_IMG.base" | _filter_qemu_io
$QEMU_IMG map --output=json "$TEST_IMG.base" | _filter_qemu_img_map
# Writing on unmapped zeroes does not allocate
$QEMU_IO -c "write -z 32M 8M" "$TEST_IMG.base" | _filter_qemu_io
$QEMU_IO -c "write -z -u 34M 2M" "$TEST_IMG.base" | _filter_qemu_io
$QEMU_IO -c "write -z 36M 2M" "$TEST_IMG.base" | _filter_qemu_io
$QEMU_IO -c "map" "$TEST_IMG.base" | _filter_qemu_io
$QEMU_IMG map --output=json "$TEST_IMG.base" | _filter_qemu_img_map
# Writing zero overrides a backing file, regardless of backing cluster type
$QEMU_IO -c "write -z 40M 8M" "$TEST_IMG.base" | _filter_qemu_io
$QEMU_IO -c "write 48M 8M" "$TEST_IMG.base" | _filter_qemu_io
$QEMU_IO -c "write -z -u 42M 2M" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "write -z 44M 2M" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "write -z -u 50M 2M" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "write -z 52M 2M" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "write -z -u 58M 2M" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "write -z 60M 2M" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "map" "$TEST_IMG" | _filter_qemu_io
$QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map
# Final check that mappings are correct and images are still sane
TEST_IMG="$TEST_IMG.base" _check_test_img
_check_test_img
echo
echo '=== Testing cache optimization ==='
echo
BLKDBG_TEST_IMG="blkdebug:$TEST_DIR/blkdebug.conf:$TEST_IMG.base"
cat > "$TEST_DIR/blkdebug.conf" <<EOF
[inject-error]
event = "l2_update"
errno = "5"
immediately = "on"
once = "off"
EOF
# None of the following writes should trigger an L2 update, because the
# cluster already reads as zero, and we don't have to change allocation
$QEMU_IO -c "w -z -u 20M 2M" "$BLKDBG_TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "w -z 20M 2M" "$BLKDBG_TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "w -z 28M 2M" "$BLKDBG_TEST_IMG" | _filter_qemu_io
# success, all done
echo '*** done'
status=0

156
tests/qemu-iotests/179.out Normal file
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QA output created by 179
=== Testing write zeroes with unmap ===
Formatting 'TEST_DIR/t.IMGFMT.base', fmt=IMGFMT size=67108864
Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 backing_file=TEST_DIR/t.IMGFMT.base
wrote 2097152/2097152 bytes at offset 2097152
2 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
wrote 2097152/2097152 bytes at offset 6291456
2 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
2 MiB (0x200000) bytes not allocated at offset 0 bytes (0x0)
2 MiB (0x200000) bytes allocated at offset 2 MiB (0x200000)
2 MiB (0x200000) bytes not allocated at offset 4 MiB (0x400000)
2 MiB (0x200000) bytes allocated at offset 6 MiB (0x600000)
56 MiB (0x3800000) bytes not allocated at offset 8 MiB (0x800000)
[{ "start": 0, "length": 67108864, "depth": 0, "zero": true, "data": false}]
wrote 2097150/2097150 bytes at offset 10485761
2 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
wrote 2097150/2097150 bytes at offset 14680065
2 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
2 MiB (0x200000) bytes not allocated at offset 0 bytes (0x0)
2 MiB (0x200000) bytes allocated at offset 2 MiB (0x200000)
2 MiB (0x200000) bytes not allocated at offset 4 MiB (0x400000)
2 MiB (0x200000) bytes allocated at offset 6 MiB (0x600000)
2 MiB (0x200000) bytes not allocated at offset 8 MiB (0x800000)
2 MiB (0x200000) bytes allocated at offset 10 MiB (0xa00000)
2 MiB (0x200000) bytes not allocated at offset 12 MiB (0xc00000)
2 MiB (0x200000) bytes allocated at offset 14 MiB (0xe00000)
48 MiB (0x3000000) bytes not allocated at offset 16 MiB (0x1000000)
[{ "start": 0, "length": 67108864, "depth": 0, "zero": true, "data": false}]
wrote 14680064/14680064 bytes at offset 18874368
14 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
wrote 2097152/2097152 bytes at offset 20971520
2 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
wrote 6291456/6291456 bytes at offset 25165824
6 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
2 MiB (0x200000) bytes not allocated at offset 0 bytes (0x0)
2 MiB (0x200000) bytes allocated at offset 2 MiB (0x200000)
2 MiB (0x200000) bytes not allocated at offset 4 MiB (0x400000)
2 MiB (0x200000) bytes allocated at offset 6 MiB (0x600000)
2 MiB (0x200000) bytes not allocated at offset 8 MiB (0x800000)
2 MiB (0x200000) bytes allocated at offset 10 MiB (0xa00000)
2 MiB (0x200000) bytes not allocated at offset 12 MiB (0xc00000)
2 MiB (0x200000) bytes allocated at offset 14 MiB (0xe00000)
2 MiB (0x200000) bytes not allocated at offset 16 MiB (0x1000000)
14 MiB (0xe00000) bytes allocated at offset 18 MiB (0x1200000)
32 MiB (0x2000000) bytes not allocated at offset 32 MiB (0x2000000)
[{ "start": 0, "length": 18874368, "depth": 0, "zero": true, "data": false},
{ "start": 18874368, "length": 2097152, "depth": 0, "zero": false, "data": true, "offset": OFFSET},
{ "start": 20971520, "length": 2097152, "depth": 0, "zero": true, "data": false},
{ "start": 23068672, "length": 2097152, "depth": 0, "zero": false, "data": true, "offset": OFFSET},
{ "start": 25165824, "length": 6291456, "depth": 0, "zero": true, "data": false, "offset": OFFSET},
{ "start": 31457280, "length": 2097152, "depth": 0, "zero": false, "data": true, "offset": OFFSET},
{ "start": 33554432, "length": 33554432, "depth": 0, "zero": true, "data": false}]
wrote 2097152/2097152 bytes at offset 27262976
2 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
wrote 2097152/2097152 bytes at offset 29360128
2 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
2 MiB (0x200000) bytes not allocated at offset 0 bytes (0x0)
2 MiB (0x200000) bytes allocated at offset 2 MiB (0x200000)
2 MiB (0x200000) bytes not allocated at offset 4 MiB (0x400000)
2 MiB (0x200000) bytes allocated at offset 6 MiB (0x600000)
2 MiB (0x200000) bytes not allocated at offset 8 MiB (0x800000)
2 MiB (0x200000) bytes allocated at offset 10 MiB (0xa00000)
2 MiB (0x200000) bytes not allocated at offset 12 MiB (0xc00000)
2 MiB (0x200000) bytes allocated at offset 14 MiB (0xe00000)
2 MiB (0x200000) bytes not allocated at offset 16 MiB (0x1000000)
14 MiB (0xe00000) bytes allocated at offset 18 MiB (0x1200000)
32 MiB (0x2000000) bytes not allocated at offset 32 MiB (0x2000000)
[{ "start": 0, "length": 18874368, "depth": 0, "zero": true, "data": false},
{ "start": 18874368, "length": 2097152, "depth": 0, "zero": false, "data": true, "offset": OFFSET},
{ "start": 20971520, "length": 2097152, "depth": 0, "zero": true, "data": false},
{ "start": 23068672, "length": 2097152, "depth": 0, "zero": false, "data": true, "offset": OFFSET},
{ "start": 25165824, "length": 2097152, "depth": 0, "zero": true, "data": false, "offset": OFFSET},
{ "start": 27262976, "length": 2097152, "depth": 0, "zero": true, "data": false},
{ "start": 29360128, "length": 2097152, "depth": 0, "zero": true, "data": false, "offset": OFFSET},
{ "start": 31457280, "length": 2097152, "depth": 0, "zero": false, "data": true, "offset": OFFSET},
{ "start": 33554432, "length": 33554432, "depth": 0, "zero": true, "data": false}]
wrote 8388608/8388608 bytes at offset 33554432
8 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
wrote 2097152/2097152 bytes at offset 35651584
2 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
wrote 2097152/2097152 bytes at offset 37748736
2 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
2 MiB (0x200000) bytes not allocated at offset 0 bytes (0x0)
2 MiB (0x200000) bytes allocated at offset 2 MiB (0x200000)
2 MiB (0x200000) bytes not allocated at offset 4 MiB (0x400000)
2 MiB (0x200000) bytes allocated at offset 6 MiB (0x600000)
2 MiB (0x200000) bytes not allocated at offset 8 MiB (0x800000)
2 MiB (0x200000) bytes allocated at offset 10 MiB (0xa00000)
2 MiB (0x200000) bytes not allocated at offset 12 MiB (0xc00000)
2 MiB (0x200000) bytes allocated at offset 14 MiB (0xe00000)
2 MiB (0x200000) bytes not allocated at offset 16 MiB (0x1000000)
22 MiB (0x1600000) bytes allocated at offset 18 MiB (0x1200000)
24 MiB (0x1800000) bytes not allocated at offset 40 MiB (0x2800000)
[{ "start": 0, "length": 18874368, "depth": 0, "zero": true, "data": false},
{ "start": 18874368, "length": 2097152, "depth": 0, "zero": false, "data": true, "offset": OFFSET},
{ "start": 20971520, "length": 2097152, "depth": 0, "zero": true, "data": false},
{ "start": 23068672, "length": 2097152, "depth": 0, "zero": false, "data": true, "offset": OFFSET},
{ "start": 25165824, "length": 2097152, "depth": 0, "zero": true, "data": false, "offset": OFFSET},
{ "start": 27262976, "length": 2097152, "depth": 0, "zero": true, "data": false},
{ "start": 29360128, "length": 2097152, "depth": 0, "zero": true, "data": false, "offset": OFFSET},
{ "start": 31457280, "length": 2097152, "depth": 0, "zero": false, "data": true, "offset": OFFSET},
{ "start": 33554432, "length": 33554432, "depth": 0, "zero": true, "data": false}]
wrote 8388608/8388608 bytes at offset 41943040
8 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
wrote 8388608/8388608 bytes at offset 50331648
8 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
wrote 2097152/2097152 bytes at offset 44040192
2 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
wrote 2097152/2097152 bytes at offset 46137344
2 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
wrote 2097152/2097152 bytes at offset 52428800
2 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
wrote 2097152/2097152 bytes at offset 54525952
2 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
wrote 2097152/2097152 bytes at offset 60817408
2 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
wrote 2097152/2097152 bytes at offset 62914560
2 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
42 MiB (0x2a00000) bytes not allocated at offset 0 bytes (0x0)
4 MiB (0x400000) bytes allocated at offset 42 MiB (0x2a00000)
4 MiB (0x400000) bytes not allocated at offset 46 MiB (0x2e00000)
4 MiB (0x400000) bytes allocated at offset 50 MiB (0x3200000)
4 MiB (0x400000) bytes not allocated at offset 54 MiB (0x3600000)
4 MiB (0x400000) bytes allocated at offset 58 MiB (0x3a00000)
2 MiB (0x200000) bytes not allocated at offset 62 MiB (0x3e00000)
[{ "start": 0, "length": 18874368, "depth": 1, "zero": true, "data": false},
{ "start": 18874368, "length": 2097152, "depth": 1, "zero": false, "data": true, "offset": OFFSET},
{ "start": 20971520, "length": 2097152, "depth": 1, "zero": true, "data": false},
{ "start": 23068672, "length": 2097152, "depth": 1, "zero": false, "data": true, "offset": OFFSET},
{ "start": 25165824, "length": 2097152, "depth": 1, "zero": true, "data": false, "offset": OFFSET},
{ "start": 27262976, "length": 2097152, "depth": 1, "zero": true, "data": false},
{ "start": 29360128, "length": 2097152, "depth": 1, "zero": true, "data": false, "offset": OFFSET},
{ "start": 31457280, "length": 2097152, "depth": 1, "zero": false, "data": true, "offset": OFFSET},
{ "start": 33554432, "length": 10485760, "depth": 1, "zero": true, "data": false},
{ "start": 44040192, "length": 4194304, "depth": 0, "zero": true, "data": false},
{ "start": 48234496, "length": 2097152, "depth": 1, "zero": true, "data": false},
{ "start": 50331648, "length": 2097152, "depth": 1, "zero": false, "data": true, "offset": OFFSET},
{ "start": 52428800, "length": 4194304, "depth": 0, "zero": true, "data": false},
{ "start": 56623104, "length": 2097152, "depth": 1, "zero": false, "data": true, "offset": OFFSET},
{ "start": 58720256, "length": 2097152, "depth": 1, "zero": true, "data": false},
{ "start": 60817408, "length": 4194304, "depth": 0, "zero": true, "data": false},
{ "start": 65011712, "length": 2097152, "depth": 1, "zero": true, "data": false}]
No errors were found on the image.
No errors were found on the image.
=== Testing cache optimization ===
wrote 2097152/2097152 bytes at offset 20971520
2 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
wrote 2097152/2097152 bytes at offset 20971520
2 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
wrote 2097152/2097152 bytes at offset 29360128
2 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
*** done

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@ -171,5 +171,6 @@
175 auto quick
176 rw auto backing
177 rw auto quick
179 rw auto quick
181 rw auto migration
182 rw auto quick