Subject: Re: [patch] svcrdma: endian bug in send_write_chunks()

From: "J. Bruce Fields" <[email-masked]>
Date: Thu, 12 Jan 2012 11:21:41 -0500

On Thu, Jan 12, 2012 at 09:47:22AM +0300, Dan Carpenter wrote:
> Sparse complains because arg_ch->rs_length is declared as network
> endian but we're treating it as CPU endian.

This looks like it would actually change behavior on a little endian
architecture, so how did this work before?

>>From some quick grepping, I see assignments both of the form

	...rs_length = ntohl(...)

and

	...rs_length = htonl(...)

but only see one declaration for a field named rs_length.

So my best guess would be that the code is ugly but working as is, and
needs cleanup by someone who knows how this field was intended to be
used.

?

--b.

> 
> Signed-off-by: Dan Carpenter <[email-masked]>
> 
> diff --git a/net/sunrpc/xprtrdma/svc_rdma_sendto.c b/net/sunrpc/xprtrdma/svc_rdma_sendto.c
> index 249a835..30fda86 100644
> --- a/net/sunrpc/xprtrdma/svc_rdma_sendto.c
> +++ b/net/sunrpc/xprtrdma/svc_rdma_sendto.c
> @@ -409,7 +409,7 @@ static int send_write_chunks(struct svcxprt_rdma *xprt,
>  		u64 rs_offset;
>  
>  		arg_ch = &arg_ary->wc_array[chunk_no].wc_target;
> -		write_len = min(xfer_len, arg_ch->rs_length);
> +		write_len = min(xfer_len, ntohl(arg_ch->rs_length));
>  
>  		/* Prepare the response chunk given the length actually
>  		 * written */
> @@ -481,7 +481,7 @@ static int send_reply_chunks(struct svcxprt_rdma *xprt,
>  	     chunk_no++) {
>  		u64 rs_offset;
>  		ch = &arg_ary->wc_array[chunk_no].wc_target;
> -		write_len = min(xfer_len, ch->rs_length);
> +		write_len = min(xfer_len, ntohl(ch->rs_length));
>  
>  		/* Prepare the reply chunk given the length actually
>  		 * written */