Re: [PATCH v5 1/4] RDMA/nldev: Add dellink function pointer

[David Ahern <dsahern@kernel.org>]

On 3/11/26 4:01 PM, Yanjun.Zhu wrote:

> Got it. The commit log explains how the netdev_notifier mechanism is

netdev notifiers are the NETDEV_UNREGISTER and friends. This dellink
handler is not related to that; this is an IB stack thing when the rxe
link is removed.

> used to clean up the related resources.
> 
> In the source code, additional comments have been added to explain how
> the dellink operation for rxe is triggered. For iWARP, this change
> should not make any difference because iWARP does not implement the
> dellink function.
> 
> The commit is shown below. Please take a look and share your comments.
> If you agree, I will send out the latest commits out very soon.
> 
> From c05038dcdf69c5985837736a8926ba76d9f3e8e4 Mon Sep 17 00:00:00 2001
> From: Zhu Yanjun <yanjun.zhu@linux.dev>
> Date: Fri, 23 Sep 2022 16:52:45 +0000
> Subject: [PATCH 1/1] RDMA/nldev: Add dellink function pointer
> 
> The newlink function pointer was previously added to support
> dynamic RDMA link creation. In the RXE driver, this path creates
> a transport socket listening on port 4791. Consequently, a dellink
> function pointer is required to ensure these sockets are properly
> closed when a user administratively removes a link via rdma link
> delete <dev>.
> 
> Furthermore, RXE does not rely solely on this nldev path for resource
> management. It also monitors the underlying net_device state via a
> registered netdev_notifier. The rxe_net_event callback serves as a
> fallback mechanism to ensure that transport sockets are forcibly closed
> and all resources are released even if dellink is not explicitly called
> (e.g., if the parent NIC interface is removed or the driver is forcefully
> unloaded).

IMHO, this explanation belongs in the patch that implements dellink for rxe.

This patch adds the handler to allow link implementations to cleanup any
resources created by newklink as needed.