nvme_rdma: keep a ref on the ctrl during delete/flush

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimbrg.me>
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>

1 files changed, 18 insertions, 8 deletions

diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c
index ab545fb347a0..15b0c1d025f5 100644
--- a/drivers/nvme/host/rdma.c
+++ b/drivers/nvme/host/rdma.c
@@ -1351,9 +1351,15 @@ 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;
 }
 
@@ -1700,15 +1706,19 @@ 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
+         */
+        if (!kref_get_unless_zero(&ctrl->ctrl.kref))
+                return -EBUSY;
         ret = __nvme_rdma_del_ctrl(ctrl);
-        if (ret)
-                return ret;
-
-        flush_work(&ctrl->delete_work);
-
-        return 0;
+        if (!ret)
+                flush_work(&ctrl->delete_work);
+        nvme_put_ctrl(&ctrl->ctrl);
+        return ret;
 }
 
 static void nvme_rdma_remove_ctrl_work(struct work_struct *work)