nvme-rdma: Don't flush delete_wq by default during remove_one

The .remove_one function is called for any ib_device removal.
In case the removed device has no reference in our driver, there
is no need to flush the work queue.

Reviewed-by: Israel Rukshin <israelr@mellanox.com>
Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/nvme/host/rdma.c

@@ -2024,6 +2024,20 @@ static struct nvmf_transport_ops nvme_rdma_transport = {
 static void nvme_rdma_remove_one(struct ib_device *ib_device, void *client_data)
 {
 	struct nvme_rdma_ctrl *ctrl;
+	struct nvme_rdma_device *ndev;
+	bool found = false;
+
+	mutex_lock(&device_list_mutex);
+	list_for_each_entry(ndev, &device_list, entry) {
+		if (ndev->dev == ib_device) {
+			found = true;
+			break;
+		}
+	}
+	mutex_unlock(&device_list_mutex);
+
+	if (!found)
+		return;
 
 	/* Delete all controllers using this device */
 	mutex_lock(&nvme_rdma_ctrl_mutex);