migration: Use automatic rcu_read unlock in rdma.c (987ab2a5) · Commits · SUMMER2020 / students / proj-2021291

migration/rdma.c

+11 −46

Original line number	Diff line number	Diff line
		@@ -88,7 +88,6 @@ static uint32_t known_capabilities = RDMA_CAPABILITY_PIN_ALL;
		" to abort!"); \
		rdma->error_reported = 1; \
		} \
		rcu_read_unlock(); \
		return rdma->error_state; \
		} \
		} while (0)
		@@ -2678,11 +2677,10 @@ static ssize_t qio_channel_rdma_writev(QIOChannel *ioc,
		size_t i;
		size_t len = 0;

		rcu_read_lock();
		RCU_READ_LOCK_GUARD();
		rdma = atomic_rcu_read(&rioc->rdmaout);

		if (!rdma) {
		rcu_read_unlock();
		return -EIO;
		}

		@@ -2695,7 +2693,6 @@ static ssize_t qio_channel_rdma_writev(QIOChannel *ioc,
		ret = qemu_rdma_write_flush(f, rdma);
		if (ret < 0) {
		rdma->error_state = ret;
		rcu_read_unlock();
		return ret;
		}

		@@ -2715,7 +2712,6 @@ static ssize_t qio_channel_rdma_writev(QIOChannel *ioc,

		if (ret < 0) {
		rdma->error_state = ret;
		rcu_read_unlock();
		return ret;
		}

		@@ -2724,7 +2720,6 @@ static ssize_t qio_channel_rdma_writev(QIOChannel *ioc,
		}
		}

		rcu_read_unlock();
		return done;
		}

		@@ -2764,11 +2759,10 @@ static ssize_t qio_channel_rdma_readv(QIOChannel *ioc,
		ssize_t i;
		size_t done = 0;

		rcu_read_lock();
		RCU_READ_LOCK_GUARD();
		rdma = atomic_rcu_read(&rioc->rdmain);

		if (!rdma) {
		rcu_read_unlock();
		return -EIO;
		}

		@@ -2805,7 +2799,6 @@ static ssize_t qio_channel_rdma_readv(QIOChannel *ioc,

		if (ret < 0) {
		rdma->error_state = ret;
		rcu_read_unlock();
		return ret;
		}

		@@ -2819,14 +2812,12 @@ static ssize_t qio_channel_rdma_readv(QIOChannel *ioc,
		/* Still didn't get enough, so lets just return */
		if (want) {
		if (done == 0) {
		rcu_read_unlock();
		return QIO_CHANNEL_ERR_BLOCK;
		} else {
		break;
		}
		}
		}
		rcu_read_unlock();
		return done;
		}

		@@ -2882,7 +2873,7 @@ qio_channel_rdma_source_prepare(GSource *source,
		GIOCondition cond = 0;
		*timeout = -1;

		rcu_read_lock();
		RCU_READ_LOCK_GUARD();
		if (rsource->condition == G_IO_IN) {
		rdma = atomic_rcu_read(&rsource->rioc->rdmain);
		} else {
		@@ -2891,7 +2882,6 @@ qio_channel_rdma_source_prepare(GSource *source,

		if (!rdma) {
		error_report("RDMAContext is NULL when prepare Gsource");
		rcu_read_unlock();
		return FALSE;
		}

		@@ -2900,7 +2890,6 @@ qio_channel_rdma_source_prepare(GSource *source,
		}
		cond \|= G_IO_OUT;

		rcu_read_unlock();
		return cond & rsource->condition;
		}

		@@ -2911,7 +2900,7 @@ qio_channel_rdma_source_check(GSource *source)
		RDMAContext *rdma;
		GIOCondition cond = 0;

		rcu_read_lock();
		RCU_READ_LOCK_GUARD();
		if (rsource->condition == G_IO_IN) {
		rdma = atomic_rcu_read(&rsource->rioc->rdmain);
		} else {
		@@ -2920,7 +2909,6 @@ qio_channel_rdma_source_check(GSource *source)

		if (!rdma) {
		error_report("RDMAContext is NULL when check Gsource");
		rcu_read_unlock();
		return FALSE;
		}

		@@ -2929,7 +2917,6 @@ qio_channel_rdma_source_check(GSource *source)
		}
		cond \|= G_IO_OUT;

		rcu_read_unlock();
		return cond & rsource->condition;
		}

		@@ -2943,7 +2930,7 @@ qio_channel_rdma_source_dispatch(GSource *source,
		RDMAContext *rdma;
		GIOCondition cond = 0;

		rcu_read_lock();
		RCU_READ_LOCK_GUARD();
		if (rsource->condition == G_IO_IN) {
		rdma = atomic_rcu_read(&rsource->rioc->rdmain);
		} else {
		@@ -2952,7 +2939,6 @@ qio_channel_rdma_source_dispatch(GSource *source,

		if (!rdma) {
		error_report("RDMAContext is NULL when dispatch Gsource");
		rcu_read_unlock();
		return FALSE;
		}

		@@ -2961,7 +2947,6 @@ qio_channel_rdma_source_dispatch(GSource *source,
		}
		cond \|= G_IO_OUT;

		rcu_read_unlock();
		return (*func)(QIO_CHANNEL(rsource->rioc),
		(cond & rsource->condition),
		user_data);
		@@ -3073,7 +3058,7 @@ qio_channel_rdma_shutdown(QIOChannel *ioc,
		QIOChannelRDMA *rioc = QIO_CHANNEL_RDMA(ioc);
		RDMAContext rdmain, rdmaout;

		rcu_read_lock();
		RCU_READ_LOCK_GUARD();

		rdmain = atomic_rcu_read(&rioc->rdmain);
		rdmaout = atomic_rcu_read(&rioc->rdmain);
		@@ -3100,7 +3085,6 @@ qio_channel_rdma_shutdown(QIOChannel *ioc,
		break;
		}

		rcu_read_unlock();
		return 0;
		}

		@@ -3146,18 +3130,16 @@ static size_t qemu_rdma_save_page(QEMUFile f, void opaque,
		RDMAContext *rdma;
		int ret;

		rcu_read_lock();
		RCU_READ_LOCK_GUARD();
		rdma = atomic_rcu_read(&rioc->rdmaout);

		if (!rdma) {
		rcu_read_unlock();
		return -EIO;
		}

		CHECK_ERROR_STATE();

		if (migration_in_postcopy()) {
		rcu_read_unlock();
		return RAM_SAVE_CONTROL_NOT_SUPP;
		}

		@@ -3242,11 +3224,9 @@ static size_t qemu_rdma_save_page(QEMUFile f, void opaque,
		}
		}

		rcu_read_unlock();
		return RAM_SAVE_CONTROL_DELAYED;
		err:
		rdma->error_state = ret;
		rcu_read_unlock();
		return ret;
		}

		@@ -3470,11 +3450,10 @@ static int qemu_rdma_registration_handle(QEMUFile f, void opaque)
		int count = 0;
		int i = 0;

		rcu_read_lock();
		RCU_READ_LOCK_GUARD();
		rdma = atomic_rcu_read(&rioc->rdmain);

		if (!rdma) {
		rcu_read_unlock();
		return -EIO;
		}

		@@ -3717,7 +3696,6 @@ out:
		if (ret < 0) {
		rdma->error_state = ret;
		}
		rcu_read_unlock();
		return ret;
		}

		@@ -3735,11 +3713,10 @@ rdma_block_notification_handle(QIOChannelRDMA rioc, const char name)
		int curr;
		int found = -1;

		rcu_read_lock();
		RCU_READ_LOCK_GUARD();
		rdma = atomic_rcu_read(&rioc->rdmain);

		if (!rdma) {
		rcu_read_unlock();
		return -EIO;
		}

		@@ -3753,7 +3730,6 @@ rdma_block_notification_handle(QIOChannelRDMA rioc, const char name)

		if (found == -1) {
		error_report("RAMBlock '%s' not found on destination", name);
		rcu_read_unlock();
		return -ENOENT;
		}

		@@ -3761,7 +3737,6 @@ rdma_block_notification_handle(QIOChannelRDMA rioc, const char name)
		trace_rdma_block_notification_handle(name, rdma->next_src_index);
		rdma->next_src_index++;

		rcu_read_unlock();
		return 0;
		}

		@@ -3786,17 +3761,15 @@ static int qemu_rdma_registration_start(QEMUFile f, void opaque,
		QIOChannelRDMA *rioc = QIO_CHANNEL_RDMA(opaque);
		RDMAContext *rdma;

		rcu_read_lock();
		RCU_READ_LOCK_GUARD();
		rdma = atomic_rcu_read(&rioc->rdmaout);
		if (!rdma) {
		rcu_read_unlock();
		return -EIO;
		}

		CHECK_ERROR_STATE();

		if (migration_in_postcopy()) {
		rcu_read_unlock();
		return 0;
		}

		@@ -3804,7 +3777,6 @@ static int qemu_rdma_registration_start(QEMUFile f, void opaque,
		qemu_put_be64(f, RAM_SAVE_FLAG_HOOK);
		qemu_fflush(f);

		rcu_read_unlock();
		return 0;
		}

		@@ -3821,17 +3793,15 @@ static int qemu_rdma_registration_stop(QEMUFile f, void opaque,
		RDMAControlHeader head = { .len = 0, .repeat = 1 };
		int ret = 0;

		rcu_read_lock();
		RCU_READ_LOCK_GUARD();
		rdma = atomic_rcu_read(&rioc->rdmaout);
		if (!rdma) {
		rcu_read_unlock();
		return -EIO;
		}

		CHECK_ERROR_STATE();

		if (migration_in_postcopy()) {
		rcu_read_unlock();
		return 0;
		}

		@@ -3863,7 +3833,6 @@ static int qemu_rdma_registration_stop(QEMUFile f, void opaque,
		qemu_rdma_reg_whole_ram_blocks : NULL);
		if (ret < 0) {
		ERROR(errp, "receiving remote info!");
		rcu_read_unlock();
		return ret;
		}

		@@ -3887,7 +3856,6 @@ static int qemu_rdma_registration_stop(QEMUFile f, void opaque,
		"not identical on both the source and destination.",
		local->nb_blocks, nb_dest_blocks);
		rdma->error_state = -EINVAL;
		rcu_read_unlock();
		return -EINVAL;
		}

		@@ -3904,7 +3872,6 @@ static int qemu_rdma_registration_stop(QEMUFile f, void opaque,
		local->block[i].length,
		rdma->dest_blocks[i].length);
		rdma->error_state = -EINVAL;
		rcu_read_unlock();
		return -EINVAL;
		}
		local->block[i].remote_host_addr =
		@@ -3922,11 +3889,9 @@ static int qemu_rdma_registration_stop(QEMUFile f, void opaque,
		goto err;
		}

		rcu_read_unlock();
		return 0;
		err:
		rdma->error_state = ret;
		rcu_read_unlock();
		return ret;
		}