SUNRPC: Add a transport-specific private field in rpc_rqst

Currently there's a hidden and indirect mechanism for finding the
rpcrdma_req that goes with an rpc_rqst. It depends on getting from
the rq_buffer pointer in struct rpc_rqst to the struct
rpcrdma_regbuf that controls that buffer, and then to the struct
rpcrdma_req it goes with.

This was done back in the day to avoid the need to add a per-rqst
pointer or to alter the buf_free API when support for RPC-over-RDMA
was introduced.

I'm about to change the way regbuf's work to support larger inline
thresholds. Now is a good time to replace this indirect mechanism
with something that is more straightforward. I guess this should be
considered a clean up.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

1 files changed, 7 insertions, 6 deletions

diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h
index 4838a85..484855e 100644
--- a/net/sunrpc/xprtrdma/xprt_rdma.h
+++ b/net/sunrpc/xprtrdma/xprt_rdma.h
@@ -113,7 +113,6 @@ struct rpcrdma_ep {
 
 struct rpcrdma_regbuf {
 	size_t			rg_size;
-	struct rpcrdma_req	*rg_owner;
 	struct ib_sge		rg_iov;
 	__be32			rg_base[0] __attribute__ ((aligned(256)));
 };
@@ -297,14 +296,16 @@ struct rpcrdma_req {
 	struct rpcrdma_mr_seg	rl_segments[RPCRDMA_MAX_SEGS];
 };
 
+static inline void
+rpcrdma_set_xprtdata(struct rpc_rqst *rqst, struct rpcrdma_req *req)
+{
+	rqst->rq_xprtdata = req;
+}
+
 static inline struct rpcrdma_req *
 rpcr_to_rdmar(struct rpc_rqst *rqst)
 {
-	void *buffer = rqst->rq_buffer;
-	struct rpcrdma_regbuf *rb;
-
-	rb = container_of(buffer, struct rpcrdma_regbuf, rg_base);
-	return rb->rg_owner;
+	return rqst->rq_xprtdata;
 }
 
 /*