performance: 0.877 device: 0.837 graphic: 0.816 debug: 0.661 vnc: 0.528 files: 0.488 boot: 0.477 network: 0.438 semantic: 0.396 socket: 0.297 PID: 0.229 permissions: 0.188 other: 0.049 KVM: 0.019 Data races in test-bdrv-drain test Description of problem: Data races in the access of `Job` fields in the `test-bdrv-drain` test were identified using TSAN. Steps to reproduce: ```sh QEMU_BUILD_DIR= QEMU_DIR= configure --enable-tsan --cc=clang --cxx=clang++ --enable-trace-backends=ust --enable-fdt=system --disable-slirp make tests/unit/test-bdrv-drain MALLOC_PERTURB_=186 G_TEST_SRCDIR=$QEMU_BUILD_DIR/tests/unit G_TEST_BUILDDIR=$QEMU_BUILD_DIR/tests/unit $QEMU_BUILD_DIR/tests/unit/test-bdrv-drain --tap -k ```