Re: [PATCH 0/2] smbdirect: don't hang on netdev reconfiguration
From: Leon Romanovsky
Date: Tue Sep 22 2026 - 11:50:46 EST
On Tue, 08 Sep 2026 08:44:25 -0700, Ammar Ratnani wrote:
> When I mount a CIFS share using SMB Direct over RoCEv2, I observe a kernel
> thread hang if I "configure" its slave network device by taking its link
> down and bringing it back up. Attempting to just `ls` the mount point in
> this state gives EHOSTDOWN.
>
> I believe the following is the root-cause of the hang: When the link is
> taken down, the corresponding GID Table Entry is marked as pending deletion
> and has its slave ndev set to NULL. All sends on RDMA connections still
> using that GID Table Entry fail at MAD creation. SMB Direct eventually
> detects this and tries to disconnect / reconnect to recover. Unfortunately,
> disconnecting requires successfully sending either a DREQ or a DREP. Since
> neither of them even post, the connection remains in the RDMA_CM_CONNECT
> state, and no callback moves it out. The SMB Direct layer never gets the
> RDMA_CM_EVENT_DISCONNECTED it's waiting for, and hangs.
>
> [...]
Applied, thanks!
[1/2] infiniband: force disconnect if DREP and DREQ fail
https://git.kernel.org/rdma/rdma/c/ba88a28b47a703
[2/2] infiniband: trace force disconnections
(no commit info)
Best regards,
--
Leon Romanovsky <leon@xxxxxxxxxx>