graphic: 0.846 device: 0.807 performance: 0.802 debug: 0.645 files: 0.551 vnc: 0.524 permissions: 0.505 semantic: 0.440 ppc: 0.429 network: 0.377 boot: 0.371 PID: 0.359 socket: 0.335 i386: 0.324 TCG: 0.297 risc-v: 0.231 arm: 0.215 x86: 0.215 architecture: 0.204 register: 0.137 VMM: 0.110 user-level: 0.105 virtual: 0.096 mistranslation: 0.084 peripherals: 0.082 kernel: 0.078 hypervisor: 0.032 assembly: 0.028 KVM: 0.028 Data races in TestBlockJob fields in test-block-iothread Description of problem: A data race in the access of `TestBlockJob` fields in `tests/unit/test-block-iothread.c` was 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-block-iothread MALLOC_PERTURB_=67 G_TEST_SRCDIR=$QEMU_BUILD_DIR/tests/unit G_TEST_BUILDDIR=$QEMU_BUILD_DIR/tests/unit $QEMU_BUILD_DIR/tests/unit/test-block-iothread --tap -k ```