diff --git a/fs/fuse/virtio_fs.c b/fs/fuse/virtio_fs.c index 3ea613d5e34f..2de8fc0d6a24 100644 --- a/fs/fuse/virtio_fs.c +++ b/fs/fuse/virtio_fs.c @@ -55,6 +55,9 @@ struct virtio_fs_forget { struct list_head list; }; +static int virtio_fs_enqueue_req(struct virtio_fs_vq *fsvq, + struct fuse_req *req, bool in_flight); + static inline struct virtio_fs_vq *vq_to_fsvq(struct virtqueue *vq) { struct virtio_fs *fs = vq->vdev->priv; @@ -260,6 +263,7 @@ static void virtio_fs_request_dispatch_work(struct work_struct *work) struct virtio_fs_vq *fsvq = container_of(work, struct virtio_fs_vq, dispatch_work.work); struct fuse_conn *fc = fsvq->fud->fc; + int ret; pr_debug("virtio-fs: worker %s called.\n", __func__); while (1) { @@ -268,13 +272,45 @@ static void virtio_fs_request_dispatch_work(struct work_struct *work) list); if (!req) { spin_unlock(&fsvq->lock); - return; + break; } list_del_init(&req->list); spin_unlock(&fsvq->lock); fuse_request_end(fc, req); } + + /* Dispatch pending requests */ + while (1) { + spin_lock(&fsvq->lock); + req = list_first_entry_or_null(&fsvq->queued_reqs, + struct fuse_req, list); + if (!req) { + spin_unlock(&fsvq->lock); + return; + } + list_del_init(&req->list); + spin_unlock(&fsvq->lock); + + ret = virtio_fs_enqueue_req(fsvq, req, true); + if (ret < 0) { + if (ret == -ENOMEM || ret == -ENOSPC) { + spin_lock(&fsvq->lock); + list_add_tail(&req->list, &fsvq->queued_reqs); + schedule_delayed_work(&fsvq->dispatch_work, + msecs_to_jiffies(1)); + spin_unlock(&fsvq->lock); + return; + } + req->out.h.error = ret; + spin_lock(&fsvq->lock); + dec_in_flight_req(fsvq); + spin_unlock(&fsvq->lock); + pr_err("virtio-fs: virtio_fs_enqueue_req() failed %d\n", + ret); + fuse_request_end(fc, req); + } + } } static void virtio_fs_hiprio_dispatch_work(struct work_struct *work) @@ -837,7 +873,7 @@ static unsigned int sg_init_fuse_args(struct scatterlist *sg, /* Add a request to a virtqueue and kick the device */ static int virtio_fs_enqueue_req(struct virtio_fs_vq *fsvq, - struct fuse_req *req) + struct fuse_req *req, bool in_flight) { /* requests need at least 4 elements */ struct scatterlist *stack_sgs[6]; @@ -917,7 +953,8 @@ static int virtio_fs_enqueue_req(struct virtio_fs_vq *fsvq, /* matches barrier in request_wait_answer() */ smp_mb__after_atomic(); - inc_in_flight_req(fsvq); + if (!in_flight) + inc_in_flight_req(fsvq); notify = virtqueue_kick_prepare(vq); spin_unlock(&fsvq->lock); @@ -963,15 +1000,21 @@ __releases(fiq->lock) req->in.h.nodeid, req->in.h.len, fuse_len_args(req->args->out_numargs, req->args->out_args)); -retry: fsvq = &fs->vqs[queue_id]; - ret = virtio_fs_enqueue_req(fsvq, req); + ret = virtio_fs_enqueue_req(fsvq, req, false); if (ret < 0) { if (ret == -ENOMEM || ret == -ENOSPC) { - /* Virtqueue full. Retry submission */ - /* TODO use completion instead of timeout */ - usleep_range(20, 30); - goto retry; + /* + * Virtqueue full. Retry submission from worker + * context as we might be holding fc->bg_lock. + */ + spin_lock(&fsvq->lock); + list_add_tail(&req->list, &fsvq->queued_reqs); + inc_in_flight_req(fsvq); + schedule_delayed_work(&fsvq->dispatch_work, + msecs_to_jiffies(1)); + spin_unlock(&fsvq->lock); + return; } req->out.h.error = ret; pr_err("virtio-fs: virtio_fs_enqueue_req() failed %d\n", ret);