While we wait for queue to finish draining, use completions instead of uslee_range(). This is better way of waiting for event.
Signed-off-by: Vivek Goyal <[email protected]> --- fs/fuse/virtio_fs.c | 39 +++++++++++++++++++++++++++++---------- 1 file changed, 29 insertions(+), 10 deletions(-) diff --git a/fs/fuse/virtio_fs.c b/fs/fuse/virtio_fs.c index 43224db8d9ed..b5ba83ef1914 100644 --- a/fs/fuse/virtio_fs.c +++ b/fs/fuse/virtio_fs.c @@ -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) { - spin_unlock(&fsvq->lock); - break; - } + spin_lock(&fsvq->lock); + 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); + 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); -- 2.20.1 _______________________________________________ Virtualization mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/virtualization
