[Qemu-devel] [PATCH v10 05/17] iotests: Add test 179 to cover write zeroes with unmap

[Eric Blake]

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).

Signed-off-by: Eric Blake <address@hidden>

---
v10: drop any changes to v2 files, rewrite test to work with updates
earlier in the series, add a blkdebug probe
v9: new patch
---
 tests/qemu-iotests/179     | 123 +++++++++++++++++++++++++++++++++++++++++++++
 tests/qemu-iotests/179.out |  90 +++++++++++++++++++++++++++++++++
 tests/qemu-iotests/group   |   1 +
 3 files changed, 214 insertions(+)
 create mode 100755 tests/qemu-iotests/179
 create mode 100644 tests/qemu-iotests/179.out

diff --git a/tests/qemu-iotests/179 b/tests/qemu-iotests/179
new file mode 100755
index 0000000..4e4ffce
--- /dev/null
+++ b/tests/qemu-iotests/179
@@ -0,0 +1,123 @@
+#!/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
address@hidden
+
+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 any cluster size
+
+# 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
+
+# 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
+
+# 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
+
+# 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
+
+# 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
+
+# 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
+
+# Final check that mappings are correct and images are still sane
+$QEMU_IO -c "map" "$TEST_IMG.base" | _filter_qemu_io
+$QEMU_IMG map --output=json "$TEST_IMG" | _filter_qemu_img_map |
+    sed 's/"offset": [0-9]*/"offset": OFFSET/g'
+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
+
+# Proof that our blkdebug hook works
+$QEMU_IO -c "w -z -u 0M 2M" "$BLKDBG_TEST_IMG" | _filter_qemu_io
+
+# success, all done
+echo '*** done'
+status=0
diff --git a/tests/qemu-iotests/179.out b/tests/qemu-iotests/179.out
new file mode 100644
index 0000000..2c3071b
--- /dev/null
+++ b/tests/qemu-iotests/179.out
@@ -0,0 +1,90 @@
+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)
+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)
+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)
+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)
+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)
+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)
+[                       0]     4096/  131072 sectors not allocated at offset 0 
bytes (0)
+[                 2097152]     4096/  126976 sectors     allocated at offset 2 
MiB (1)
+[                 4194304]     4096/  122880 sectors not allocated at offset 4 
MiB (0)
+[                 6291456]     4096/  118784 sectors     allocated at offset 6 
MiB (1)
+[                 8388608]     4096/  114688 sectors not allocated at offset 8 
MiB (0)
+[                10485760]     4096/  110592 sectors     allocated at offset 
10 MiB (1)
+[                12582912]     4096/  106496 sectors not allocated at offset 
12 MiB (0)
+[                14680064]     4096/  102400 sectors     allocated at offset 
14 MiB (1)
+[                16777216]     4096/   98304 sectors not allocated at offset 
16 MiB (0)
+[                18874368]    77824/   94208 sectors     allocated at offset 
18 MiB (1)
+[                58720256]    16384/   16384 sectors not allocated at offset 
56 MiB (0)
+[{ "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)
+Failed to flush the L2 table cache: Input/output error
+Failed to flush the refcount block cache: Input/output error
+wrote 2097152/2097152 bytes at offset 0
+2 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+*** done
diff --git a/tests/qemu-iotests/group b/tests/qemu-iotests/group
index 893962d..11ba1d9 100644
--- a/tests/qemu-iotests/group
+++ b/tests/qemu-iotests/group
@@ -169,4 +169,5 @@
 174 auto
 175 auto quick
 176 rw auto backing
+179 rw auto quick
 181 rw auto migration
-- 
2.9.3