virtio_pmem_freeze() currently deletes virtqueues and resets the device without waking threads waiting for a virtqueue descriptor or a host completion.
Mark the request virtqueue broken before reset. This makes new submissions fail fast and lets -ENOSPC waiters leave the wait list. Reset the device before draining used and unused request tokens, then delete the virtqueues. This wakes waiters with -EIO. It also keeps the detach call on a quiesced device. Clear req_vq after del_vqs(), and make drain tolerate a NULL queue, so remove after freeze does not dereference a stale virtqueue pointer. Signed-off-by: Li Chen <[email protected]> --- Changes in v6: - Clear req_vq after del_vqs() and make drain tolerate a NULL queue. Changes in v5: - Reset the device before draining used and unused request tokens. - Use the split broken-marking and post-reset drain helpers. v2->v3: - No change. v3->v4: - Rebased onto v7.1-rc7 and renumbered after the flush error patches. drivers/nvdimm/nd_virtio.c | 3 +++ drivers/nvdimm/virtio_pmem.c | 36 +++++++++++++++++++++++++++++++----- 2 files changed, 34 insertions(+), 5 deletions(-) diff --git a/drivers/nvdimm/nd_virtio.c b/drivers/nvdimm/nd_virtio.c index fb9391ebc46e7..ce4032dc07628 100644 --- a/drivers/nvdimm/nd_virtio.c +++ b/drivers/nvdimm/nd_virtio.c @@ -93,6 +93,9 @@ void virtio_pmem_drain(struct virtio_pmem *vpmem) struct virtio_pmem_request *req; unsigned int len; + if (!vpmem->req_vq) + return; + while ((req = virtqueue_get_buf(vpmem->req_vq, &len)) != NULL) { virtio_pmem_clear_inflight(vpmem, req); virtio_pmem_complete_err(req); diff --git a/drivers/nvdimm/virtio_pmem.c b/drivers/nvdimm/virtio_pmem.c index b272e9279ef23..fef792f725db2 100644 --- a/drivers/nvdimm/virtio_pmem.c +++ b/drivers/nvdimm/virtio_pmem.c @@ -17,11 +17,16 @@ static struct virtio_device_id id_table[] = { /* Initialize virt queue */ static int init_vq(struct virtio_pmem *vpmem) { + int err; + /* single vq */ vpmem->req_vq = virtio_find_single_vq(vpmem->vdev, virtio_pmem_host_ack, "flush_queue"); - if (IS_ERR(vpmem->req_vq)) - return PTR_ERR(vpmem->req_vq); + if (IS_ERR(vpmem->req_vq)) { + err = PTR_ERR(vpmem->req_vq); + vpmem->req_vq = NULL; + return err; + } spin_lock_init(&vpmem->pmem_lock); INIT_LIST_HEAD(&vpmem->req_list); @@ -31,6 +36,15 @@ static int init_vq(struct virtio_pmem *vpmem) return 0; }; +static void virtio_pmem_del_vqs(struct virtio_pmem *vpmem) +{ + if (!vpmem->req_vq) + return; + + vpmem->vdev->config->del_vqs(vpmem->vdev); + vpmem->req_vq = NULL; +} + static int virtio_pmem_validate(struct virtio_device *vdev) { struct virtio_shm_region shm_reg; @@ -132,7 +146,7 @@ static int virtio_pmem_probe(struct virtio_device *vdev) virtio_reset_device(vdev); nvdimm_bus_unregister(vpmem->nvdimm_bus); out_vq: - vdev->config->del_vqs(vdev); + virtio_pmem_del_vqs(vpmem); out_err: return err; } @@ -154,14 +168,26 @@ static void virtio_pmem_remove(struct virtio_device *vdev) spin_unlock_irqrestore(&vpmem->pmem_lock, flags); nvdimm_bus_unregister(nvdimm_bus); - vdev->config->del_vqs(vdev); + virtio_pmem_del_vqs(vpmem); } static int virtio_pmem_freeze(struct virtio_device *vdev) { - vdev->config->del_vqs(vdev); + struct virtio_pmem *vpmem = vdev->priv; + unsigned long flags; + + spin_lock_irqsave(&vpmem->pmem_lock, flags); + virtio_pmem_mark_broken(vpmem); + spin_unlock_irqrestore(&vpmem->pmem_lock, flags); + virtio_reset_device(vdev); + spin_lock_irqsave(&vpmem->pmem_lock, flags); + virtio_pmem_drain(vpmem); + spin_unlock_irqrestore(&vpmem->pmem_lock, flags); + + virtio_pmem_del_vqs(vpmem); + return 0; } -- 2.52.0
