Re: [PATCH 1/2] cifs: client: force multichannel=off when max_channels=1

[Henrique Carvalho <henrique.carvalho@suse.com>]

Hi Rajasi,

On 9/22/25 5:24 AM, rajasimandalos@gmail.com wrote:
> From: Rajasi Mandal <rajasimandal@microsoft.com>
> 
> Previously, specifying both multichannel and max_channels=1 as mount
> options would leave multichannel enabled, even though it is not
> meaningful when only one channel is allowed. This led to confusion and
> inconsistent behavior, as the client would advertise multichannel
> capability but never establish secondary channels.
> 
> Fix this by forcing multichannel to false whenever max_channels=1,
> ensuring the mount configuration is consistent and matches user intent.
> This prevents the client from advertising or attempting multichannel
> support when it is not possible.
> 
> Signed-off-by: Rajasi Mandal <rajasimandal@microsoft.com>
> ---
>  fs/smb/client/fs_context.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/fs/smb/client/fs_context.c b/fs/smb/client/fs_context.c
> index 072383899e81..43552b44f613 100644
> --- a/fs/smb/client/fs_context.c
> +++ b/fs/smb/client/fs_context.c
> @@ -1820,6 +1820,13 @@ static int smb3_fs_context_parse_param(struct fs_context *fc,
>  		goto cifs_parse_mount_err;
>  	}
>  
> +	/*
> +	 * Multichannel is not meaningful if max_channels is 1.
> +	 * Force multichannel to false to ensure consistent configuration.
> +	 */
> +	if (ctx->multichannel && ctx->max_channels == 1)
> +		ctx->multichannel = false;
> +
>  	return 0;
>  
>   cifs_parse_mount_err:

Do we even need ->multichannel flag at all? Maybe we could replace
->multichannel for a function that checks for max_channels > 1?

-- 
Henrique
SUSE Labs