On 03.11.25 23:10, Eric Blake wrote:
Test that all images in a qcow2 chain using an NBD backing file can be
served by the same process. Prior to the recent QIONetListener fixes,
this test would demonstrate deadlock.
The test borrows heavily from the original formula by "John Doe" in
the gitlab bug, but uses a Unix socket rather than TCP to avoid port
contention, and uses a full-blown QEMU rather than qemu-storage-daemon
since both programs were impacted.
[While preparing this patch by making the new test executable, I
noticed vvfat.out does not need execute permissions]
Fixes: https://gitlab.com/qemu-project/qemu/-/issues/3169
Signed-off-by: Eric Blake <[email protected]>
---
tests/qemu-iotests/tests/nbd-in-qcow2-chain | 84 +++++++++++++++++++
.../qemu-iotests/tests/nbd-in-qcow2-chain.out | 56 +++++++++++++
tests/qemu-iotests/tests/vvfat.out | 0
3 files changed, 140 insertions(+)
create mode 100755 tests/qemu-iotests/tests/nbd-in-qcow2-chain
create mode 100644 tests/qemu-iotests/tests/nbd-in-qcow2-chain.out
mode change 100755 => 100644 tests/qemu-iotests/tests/vvfat.out
diff --git a/tests/qemu-iotests/tests/nbd-in-qcow2-chain
b/tests/qemu-iotests/tests/nbd-in-qcow2-chain
new file mode 100755
index 00000000000..b89f74d4552
--- /dev/null
+++ b/tests/qemu-iotests/tests/nbd-in-qcow2-chain
@@ -0,0 +1,84 @@
+#!/usr/bin/env bash
+# group: rw quick
+#
+# Test of opening both server and client NBD in a qcow2 backing chain
+#
+# Copyright (C) Red Hat, Inc.
+#
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+# creator
[email protected]
+
+seq=`basename $0`
+echo "QA output created by $seq"
+
+status=1 # failure is the default!
+
+_cleanup()
+{
+ _cleanup_qemu
+ _cleanup_test_img
+ rm -f "$SOCK_DIR/nbd"
+}
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+# get standard environment, filters and checks
+cd ..
+. ./common.rc
+. ./common.filter
+. ./common.qemu
+. ./common.nbd
+
+_supported_fmt qcow2 # Hardcoded to qcow2 command line and QMP below
+_supported_proto file
+
+size=100M
+
+echo
+echo "=== Preparing base image ==="
+
+TEST_IMG="$TEST_IMG.base" _make_test_img $size
+
+echo
+echo "=== Starting QEMU and exposing base image ==="
+
+_launch_qemu -machine q35
+h1=$QEMU_HANDLE
+_send_qemu_cmd $QEMU_HANDLE '{"execute": "qmp_capabilities"}' 'return'
+_send_qemu_cmd $QEMU_HANDLE '{"execute": "blockdev-add",
+ "arguments": {"node-name":"base", "driver":"qcow2",
+ "file":{"driver":"file", "filename":"'"$TEST_IMG.base"'"}}}' 'return'
+_send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-start",
+ "arguments": {"addr":{"type":"unix",
+ "data":{"path":"'"$SOCK_DIR/nbd"'"}}}}' 'return'
+_send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-add",
+ "arguments": {"device":"base","name":"base"}}' 'return'
+
+echo
+echo "=== Creating wrapper image ==="
+
+_make_test_img -F raw -b "nbd+unix:///base?socket=$SOCK_DIR/nbd" $size
+
+echo
+echo "=== Adding wrapper image ==="
+
+_send_qemu_cmd $QEMU_HANDLE '{"execute": "blockdev-add",
+ "arguments": {"node-name":"wrap", "driver":"qcow2",
+ "file":{"driver":"file", "filename":"'"$TEST_IMG"'"}}}' 'return'
Hmm. Why don't you specify "backing": "base" here?
+_send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-add",
+ "arguments": {"device":"wrap","name":"wrap"}}' 'return'
+
+echo
+echo "=== Checking NBD server ==="
+
+$QEMU_NBD --list -k $SOCK_DIR/nbd
+
+echo
+echo "=== Cleaning up ==="
+
+_send_qemu_cmd $QEMU_HANDLE '{"execute":"quit"}' ''
+
+echo "*** done"
+rm -f $seq.full
+status=0
diff --git a/tests/qemu-iotests/tests/nbd-in-qcow2-chain.out
b/tests/qemu-iotests/tests/nbd-in-qcow2-chain.out
new file mode 100644
index 00000000000..5f1d31ae2e0
--- /dev/null
+++ b/tests/qemu-iotests/tests/nbd-in-qcow2-chain.out
@@ -0,0 +1,56 @@
+QA output created by nbd-in-qcow2-chain
+
+=== Preparing base image ===
+Formatting 'TEST_DIR/t.IMGFMT.base', fmt=IMGFMT size=104857600
+
+=== Starting QEMU and exposing base image ===
+{"execute": "qmp_capabilities"}
+{"return": {}}
+{"execute": "blockdev-add",
+ "arguments": {"node-name":"base", "driver":"IMGFMT",
+ "file":{"driver":"file", "filename":"TEST_DIR/t.IMGFMT.base"}}}
+{"return": {}}
+{"execute":"nbd-server-start",
+ "arguments": {"addr":{"type":"unix",
+ "data":{"path":"SOCK_DIR/nbd"}}}}
+{"return": {}}
+{"execute":"nbd-server-add",
+ "arguments": {"device":"base","name":"base"}}
+{"return": {}}
+
+=== Creating wrapper image ===
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=104857600
backing_file=nbd+unix:///base?socket=SOCK_DIR/nbd backing_fmt=raw
+
+=== Adding wrapper image ===
+{"execute": "blockdev-add",
+ "arguments": {"node-name":"wrap", "driver":"IMGFMT",
+ "file":{"driver":"file", "filename":"TEST_DIR/t.IMGFMT"}}}
+{"return": {}}
+{"execute":"nbd-server-add",
+ "arguments": {"device":"wrap","name":"wrap"}}
+{"return": {}}
+
+=== Checking NBD server ===
+exports available: 2
+ export: 'base'
+ size: 104857600
+ flags: 0x158f ( readonly flush fua df multi cache block-status-payload )
+ min block: 1
+ opt block: 4096
+ max block: 33554432
+ transaction size: 64-bit
+ available meta contexts: 1
+ base:allocation
+ export: 'wrap'
+ size: 104857600
+ flags: 0x158f ( readonly flush fua df multi cache block-status-payload )
+ min block: 1
+ opt block: 4096
+ max block: 33554432
+ transaction size: 64-bit
+ available meta contexts: 1
+ base:allocation
+
+=== Cleaning up ===
+{"execute":"quit"}
+*** done
diff --git a/tests/qemu-iotests/tests/vvfat.out
b/tests/qemu-iotests/tests/vvfat.out
old mode 100755
new mode 100644
--
Best regards,
Vladimir
