[PATCH WIP/RFC 3/6] nvme_rdma: keep a ref on the ctrl during delete/flush

[Steve Wise]

Signed-off-by: Steve Wise <swise at opengridcomputing.com>
---
 drivers/nvme/host/rdma.c | 23 ++++++++++++++++++-----
 1 file changed, 18 insertions(+), 5 deletions(-)

diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c
index c133256..00943cd 100644
--- a/drivers/nvme/host/rdma.c
+++ b/drivers/nvme/host/rdma.c
@@ -1356,9 +1356,15 @@ static int nvme_rdma_device_unplug(struct nvme_rdma_queue *queue)
 		ret = 1;
 	}
 
-	/* Queue controller deletion */
+	/*
+	 * Queue controller deletion. Keep a reference until all
+	 * work is flushed since delete_work will free the ctrl mem
+	 */
+	kref_get(&ctrl->ctrl.kref);
 	queue_work(nvme_rdma_wq, &ctrl->delete_work);
 	flush_work(&ctrl->delete_work);
+	nvme_put_ctrl(&ctrl->ctrl);
+
 	return ret;
 }
 
@@ -1705,15 +1711,22 @@ static int __nvme_rdma_del_ctrl(struct nvme_rdma_ctrl *ctrl)
 static int nvme_rdma_del_ctrl(struct nvme_ctrl *nctrl)
 {
 	struct nvme_rdma_ctrl *ctrl = to_rdma_ctrl(nctrl);
-	int ret;
+	int ret = 0;
+
+	/*
+	 * Keep a reference until all work is flushed since
+	 * __nvme_rdma_del_ctrl can free the ctrl mem
+	 */
+	kref_get(&ctrl->ctrl.kref);
 
 	ret = __nvme_rdma_del_ctrl(ctrl);
 	if (ret)
-		return ret;
+		goto out;
 
 	flush_work(&ctrl->delete_work);
-
-	return 0;
+out:
+	nvme_put_ctrl(&ctrl->ctrl);
+	return ret;
 }
 
 static void nvme_rdma_remove_ctrl_work(struct work_struct *work)
-- 
2.7.0