[Qemu-devel] [PATCH 6/7] qemu-iotests: 141: reduce likelihood of race condition on systems with fast IO

[Sascha Silbe <silbe@linux.vnet.ibm.com>]

On systems with fast IO, qemu-io may write more than 1 MiB before
receiving the block-job-cancel command, causing the test case to fail.

141 is inherently racy, but we can at least reduce the likelihood of the
job completing before the cancel command arrives by bumping the size of
the data getting written; we'll try 32 MiB for a start.

Once we actually move enough data around for the block job not to
complete prematurely, the test will still fail because the offset value
in the BLOCK_JOB_CANCELLED event will vary. Since this is more or less
inherent to the nature of this event, we just replace it with a fixed
value globally (in _filter_qmp), the same way we handle timestamps.

Signed-off-by: Sascha Silbe <silbe@linux.vnet.ibm.com>
Reviewed-by: Bo Tu <tubo@linux.vnet.ibm.com>
---
 tests/qemu-iotests/141           | 11 ++++++-----
 tests/qemu-iotests/141.out       | 24 ++++++++++++------------
 tests/qemu-iotests/common.filter |  1 +
 3 files changed, 19 insertions(+), 17 deletions(-)

diff --git a/tests/qemu-iotests/141 b/tests/qemu-iotests/141
index f7c28b4..a06dc72 100755
--- a/tests/qemu-iotests/141
+++ b/tests/qemu-iotests/141
@@ -83,9 +83,10 @@ test_blockjob()
 }
 
 
-TEST_IMG="$TEST_DIR/b.$IMGFMT" _make_test_img 1M
-TEST_IMG="$TEST_DIR/m.$IMGFMT" _make_test_img -b "$TEST_DIR/b.$IMGFMT" 1M
-_make_test_img -b "$TEST_DIR/m.$IMGFMT" 1M
+IMGSIZE=32M
+TEST_IMG="$TEST_DIR/b.$IMGFMT" _make_test_img "${IMGSIZE}"
+TEST_IMG="$TEST_DIR/m.$IMGFMT" _make_test_img -b "$TEST_DIR/b.$IMGFMT" "${IMGSIZE}"
+_make_test_img -b "$TEST_DIR/m.$IMGFMT" "${IMGSIZE}"
 
 _launch_qemu -nodefaults
 
@@ -147,7 +148,7 @@ echo
 # immediately, send a BLOCK_JOB_COMPLETED and ejecting the BDS would work just
 # fine without the block job still running.
 
-$QEMU_IO -c 'write 0 1M' "$TEST_DIR/m.$IMGFMT" | _filter_qemu_io
+$QEMU_IO -c "write 0 ${IMGSIZE}" "$TEST_DIR/m.$IMGFMT" | _filter_qemu_io
 
 test_blockjob \
     "{'execute': 'block-commit',
@@ -165,7 +166,7 @@ echo
 # immediately, send a BLOCK_JOB_COMPLETED and ejecting the BDS would work just
 # fine without the block job still running.
 
-$QEMU_IO -c 'write 0 1M' "$TEST_DIR/b.$IMGFMT" | _filter_qemu_io
+$QEMU_IO -c "write 0 ${IMGSIZE}" "$TEST_DIR/b.$IMGFMT" | _filter_qemu_io
 
 # With some data to stream (and @speed set to 1), block-stream will not complete
 # until we send the block-job-cancel command. Therefore, no event other than
diff --git a/tests/qemu-iotests/141.out b/tests/qemu-iotests/141.out
index adceac1..14e457f 100644
--- a/tests/qemu-iotests/141.out
+++ b/tests/qemu-iotests/141.out
@@ -1,23 +1,23 @@
 QA output created by 141
-Formatting 'TEST_DIR/b.IMGFMT', fmt=IMGFMT size=1048576
-Formatting 'TEST_DIR/m.IMGFMT', fmt=IMGFMT size=1048576 backing_file=TEST_DIR/b.IMGFMT
-Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1048576 backing_file=TEST_DIR/m.IMGFMT
+Formatting 'TEST_DIR/b.IMGFMT', fmt=IMGFMT size=33554432
+Formatting 'TEST_DIR/m.IMGFMT', fmt=IMGFMT size=33554432 backing_file=TEST_DIR/b.IMGFMT
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=33554432 backing_file=TEST_DIR/m.IMGFMT
 {"return": {}}
 
 === Testing drive-backup ===
 
 {"return": {}}
-Formatting 'TEST_DIR/o.IMGFMT', fmt=IMGFMT size=1048576 backing_file=TEST_DIR/t.IMGFMT backing_fmt=IMGFMT
+Formatting 'TEST_DIR/o.IMGFMT', fmt=IMGFMT size=33554432 backing_file=TEST_DIR/t.IMGFMT backing_fmt=IMGFMT
 {"return": {}}
 {"error": {"class": "GenericError", "desc": "Node 'drv0' is busy: block device is in use by block job: backup"}}
 {"return": {}}
-{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "BLOCK_JOB_CANCELLED", "data": {"device": "drv0", "len": 1048576, "offset": 0, "speed": 0, "type": "backup"}}
+{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "BLOCK_JOB_CANCELLED", "data": {"device": "drv0", "len": 33554432, "offset": OFFSET, "speed": 0, "type": "backup"}}
 {"return": {}}
 
 === Testing drive-mirror ===
 
 {"return": {}}
-Formatting 'TEST_DIR/o.IMGFMT', fmt=IMGFMT size=1048576 backing_file=TEST_DIR/t.IMGFMT backing_fmt=IMGFMT
+Formatting 'TEST_DIR/o.IMGFMT', fmt=IMGFMT size=33554432 backing_file=TEST_DIR/t.IMGFMT backing_fmt=IMGFMT
 {"return": {}}
 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "BLOCK_JOB_READY", "data": {"device": "drv0", "len": 0, "offset": 0, "speed": 0, "type": "mirror"}}
 {"error": {"class": "GenericError", "desc": "Node 'drv0' is busy: block device is in use by block job: mirror"}}
@@ -37,23 +37,23 @@ Formatting 'TEST_DIR/o.IMGFMT', fmt=IMGFMT size=1048576 backing_file=TEST_DIR/t.
 
 === Testing non-active block-commit ===
 
-wrote 1048576/1048576 bytes at offset 0
-1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 33554432/33554432 bytes at offset 0
+32 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 {"return": {}}
 {"return": {}}
 {"error": {"class": "GenericError", "desc": "Node 'drv0' is busy: block device is in use by block job: commit"}}
 {"return": {}}
-{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "BLOCK_JOB_CANCELLED", "data": {"device": "drv0", "len": 1048576, "offset": 524288, "speed": 1, "type": "commit"}}
+{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "BLOCK_JOB_CANCELLED", "data": {"device": "drv0", "len": 33554432, "offset": OFFSET, "speed": 1, "type": "commit"}}
 {"return": {}}
 
 === Testing block-stream ===
 
-wrote 1048576/1048576 bytes at offset 0
-1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 33554432/33554432 bytes at offset 0
+32 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 {"return": {}}
 {"return": {}}
 {"error": {"class": "GenericError", "desc": "Node 'drv0' is busy: block device is in use by block job: stream"}}
 {"return": {}}
-{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "BLOCK_JOB_CANCELLED", "data": {"device": "drv0", "len": 1048576, "offset": 524288, "speed": 1, "type": "stream"}}
+{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "BLOCK_JOB_CANCELLED", "data": {"device": "drv0", "len": 33554432, "offset": OFFSET, "speed": 1, "type": "stream"}}
 {"return": {}}
 *** done
diff --git a/tests/qemu-iotests/common.filter b/tests/qemu-iotests/common.filter
index 84b7434..1698d7b 100644
--- a/tests/qemu-iotests/common.filter
+++ b/tests/qemu-iotests/common.filter
@@ -173,6 +173,7 @@ _filter_qmp()
 {
     _filter_win32 | \
     sed -e 's#\("\(micro\)\?seconds": \)[0-9]\+#\1 TIMESTAMP#g' \
+        -e '/^{"timestamp": {[^}]*}, "event": "BLOCK_JOB_CANCELLED"/ s#\("offset": \)[0-9]\+#\1 OFFSET#' \
         -e 's#^{"QMP":.*}$#QMP_VERSION#' \
         -e '/^    "QMP": {\s*$/, /^    }\s*$/ c\' \
         -e '    QMP_VERSION'
-- 
1.9.1