virtiofs: Use completions while waiting for queue to be drained (724c15a4) · Commits · 戴 / test

fs/fuse/virtio_fs.c

+29 −10

Original line number	Diff line number	Diff line
		@@ -35,6 +35,7 @@ struct virtio_fs_vq {
		struct fuse_dev *fud;
		bool connected;
		long in_flight;
		struct completion in_flight_zero; /* No inflight requests */
		char name[24];
		} ____cacheline_aligned_in_smp;

		@@ -85,6 +86,8 @@ static inline void dec_in_flight_req(struct virtio_fs_vq *fsvq)
		{
		WARN_ON(fsvq->in_flight <= 0);
		fsvq->in_flight--;
		if (!fsvq->in_flight)
		complete(&fsvq->in_flight_zero);
		}

		static void release_virtio_fs_obj(struct kref *ref)
		@@ -115,22 +118,23 @@ static void virtio_fs_drain_queue(struct virtio_fs_vq *fsvq)
		WARN_ON(fsvq->in_flight < 0);

		/* Wait for in flight requests to finish.*/
		while (1) {
		spin_lock(&fsvq->lock);
		if (!fsvq->in_flight) {
		if (fsvq->in_flight) {
		/* We are holding virtio_fs_mutex. There should not be any
		* waiters waiting for completion.
		*/
		reinit_completion(&fsvq->in_flight_zero);
		spin_unlock(&fsvq->lock);
		break;
		}
		wait_for_completion(&fsvq->in_flight_zero);
		} else {
		spin_unlock(&fsvq->lock);
		/* TODO use completion instead of timeout */
		usleep_range(1000, 2000);
		}

		flush_work(&fsvq->done_work);
		flush_delayed_work(&fsvq->dispatch_work);
		}

		static void virtio_fs_drain_all_queues(struct virtio_fs *fs)
		static void virtio_fs_drain_all_queues_locked(struct virtio_fs *fs)
		{
		struct virtio_fs_vq *fsvq;
		int i;
		@@ -141,6 +145,19 @@ static void virtio_fs_drain_all_queues(struct virtio_fs *fs)
		}
		}

		static void virtio_fs_drain_all_queues(struct virtio_fs *fs)
		{
		/* Provides mutual exclusion between ->remove and ->kill_sb
		* paths. We don't want both of these draining queue at the
		* same time. Current completion logic reinits completion
		* and that means there should not be any other thread
		* doing reinit or waiting for completion already.
		*/
		mutex_lock(&virtio_fs_mutex);
		virtio_fs_drain_all_queues_locked(fs);
		mutex_unlock(&virtio_fs_mutex);
		}

		static void virtio_fs_start_all_queues(struct virtio_fs *fs)
		{
		struct virtio_fs_vq *fsvq;
		@@ -581,6 +598,7 @@ static int virtio_fs_setup_vqs(struct virtio_device *vdev,
		INIT_LIST_HEAD(&fs->vqs[VQ_HIPRIO].end_reqs);
		INIT_DELAYED_WORK(&fs->vqs[VQ_HIPRIO].dispatch_work,
		virtio_fs_hiprio_dispatch_work);
		init_completion(&fs->vqs[VQ_HIPRIO].in_flight_zero);
		spin_lock_init(&fs->vqs[VQ_HIPRIO].lock);

		/* Initialize the requests virtqueues */
		@@ -591,6 +609,7 @@ static int virtio_fs_setup_vqs(struct virtio_device *vdev,
		virtio_fs_request_dispatch_work);
		INIT_LIST_HEAD(&fs->vqs[i].queued_reqs);
		INIT_LIST_HEAD(&fs->vqs[i].end_reqs);
		init_completion(&fs->vqs[i].in_flight_zero);
		snprintf(fs->vqs[i].name, sizeof(fs->vqs[i].name),
		"requests.%u", i - VQ_REQUEST);
		callbacks[i] = virtio_fs_vq_done;
		@@ -684,7 +703,7 @@ static void virtio_fs_remove(struct virtio_device *vdev)
		/* This device is going away. No one should get new reference */
		list_del_init(&fs->list);
		virtio_fs_stop_all_queues(fs);
		virtio_fs_drain_all_queues(fs);
		virtio_fs_drain_all_queues_locked(fs);
		vdev->config->reset(vdev);
		virtio_fs_cleanup_vqs(vdev, fs);

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