svcrdma: Clean up backchannel send header encoding

Replace C structure-based XDR decoding with pointer arithmetic.
Pointer arithmetic is considered more portable.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

diff --git a/net/sunrpc/xprtrdma/svc_rdma_backchannel.c b/net/sunrpc/xprtrdma/svc_rdma_backchannel.c
index 288e35c2d8f4d7e28a5764469d6bbeceb40d0843..b1bc7a796782f4077cc79555ec002a1f450015be 100644 (file)
--- a/net/sunrpc/xprtrdma/svc_rdma_backchannel.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_backchannel.c
@@ -200,19 +200,20 @@ rpcrdma_bc_send_request(struct svcxprt_rdma *rdma, struct rpc_rqst *rqst)
 {
        struct rpc_xprt *xprt = rqst->rq_xprt;
        struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
-       struct rpcrdma_msg *headerp = (struct rpcrdma_msg *)rqst->rq_buffer;
+       __be32 *p;
        int rc;
 
        /* Space in the send buffer for an RPC/RDMA header is reserved
         * via xprt->tsh_size.
         */
-       headerp->rm_xid = rqst->rq_xid;
-       headerp->rm_vers = rpcrdma_version;
-       headerp->rm_credit = cpu_to_be32(r_xprt->rx_buf.rb_bc_max_requests);
-       headerp->rm_type = rdma_msg;
-       headerp->rm_body.rm_chunks[0] = xdr_zero;
-       headerp->rm_body.rm_chunks[1] = xdr_zero;
-       headerp->rm_body.rm_chunks[2] = xdr_zero;
+       p = rqst->rq_buffer;
+       *p++ = rqst->rq_xid;
+       *p++ = rpcrdma_version;
+       *p++ = cpu_to_be32(r_xprt->rx_buf.rb_bc_max_requests);
+       *p++ = rdma_msg;
+       *p++ = xdr_zero;
+       *p++ = xdr_zero;
+       *p   = xdr_zero;
 
 #ifdef SVCRDMA_BACKCHANNEL_DEBUG
        pr_info("%s: %*ph\n", __func__, 64, rqst->rq_buffer);