Re: [PATCH v2] cifs: do not query ifaces on smb1 mounts

[Tom Talpey <tom@talpey.com>]

On 1/10/2023 5:23 PM, Paulo Alcantara wrote:
> Users have reported the following error on every 600 seconds
> (SMB_INTERFACE_POLL_INTERVAL) when mounting SMB1 shares:
> 
> 	CIFS: VFS: \\srv\share error -5 on ioctl to get interface list
> 
> It's supported only by SMB2+, so do not query network interfaces on
> SMB1 mounts.
> 
> Fixes: 6e1c1c08cdf3 ("cifs: periodically query network interfaces from server")
> Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
> Signed-off-by: Steve French <stfrench@microsoft.com>
> ---
> v1 -> v2:
> 	remove cifs_tcon::iface_query_poll and then check version and
> 	server's capability multichannel
> 
>   fs/cifs/connect.c | 9 ++++++---
>   1 file changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
> index d371259d6808..b2a04b4e89a5 100644
> --- a/fs/cifs/connect.c
> +++ b/fs/cifs/connect.c
> @@ -2606,11 +2606,14 @@ cifs_get_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
>   	INIT_LIST_HEAD(&tcon->pending_opens);
>   	tcon->status = TID_GOOD;
>   
> -	/* schedule query interfaces poll */
>   	INIT_DELAYED_WORK(&tcon->query_interfaces,
>   			  smb2_query_server_interfaces);
> -	queue_delayed_work(cifsiod_wq, &tcon->query_interfaces,
> -			   (SMB_INTERFACE_POLL_INTERVAL * HZ));
> +	if (ses->server->dialect >= SMB30_PROT_ID &&

The dialect test is actually unnecessary, because the server
global capability, indicating the support, is what's important.
But it's harmless to be explicit, so...

Reviewed-by: Tom Talpey <tom@talpey.com>

LGTM.

> +	    (ses->server->capabilities & SMB2_GLOBAL_CAP_MULTI_CHANNEL)) {
> +		/* schedule query interfaces poll */
> +		queue_delayed_work(cifsiod_wq, &tcon->query_interfaces,
> +				   (SMB_INTERFACE_POLL_INTERVAL * HZ));
> +	}
>   
>   	spin_lock(&cifs_tcp_ses_lock);
>   	list_add(&tcon->tcon_list, &ses->tcon_list);