xprtrdma: De-duplicate "allocate new, free old regbuf"

Clean up by providing an API to do this common task.

At this point, the difference between rpcrdma_get_sendbuf and
rpcrdma_get_recvbuf has become tiny. These can be collapsed into a
single helper.

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

1 files changed, 12 insertions, 47 deletions

diff --git a/net/sunrpc/xprtrdma/transport.c b/net/sunrpc/xprtrdma/transport.c
index a5da43f3b035..8cf4fa36ed66 100644
--- a/net/sunrpc/xprtrdma/transport.c
+++ b/net/sunrpc/xprtrdma/transport.c
@@ -585,52 +585,15 @@ xprt_rdma_free_slot(struct rpc_xprt *xprt, struct rpc_rqst *rqst)
 	rpc_wake_up_next(&xprt->backlog);
 }
 
-static bool
-rpcrdma_get_sendbuf(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req,
-		    size_t size, gfp_t flags)
+static bool rpcrdma_check_regbuf(struct rpcrdma_xprt *r_xprt,
+				 struct rpcrdma_regbuf *rb, size_t size,
+				 gfp_t flags)
 {
-	struct rpcrdma_regbuf *rb;
-
-	if (likely(rdmab_length(req->rl_sendbuf) >= size))
-		return true;
-
-	rb = rpcrdma_alloc_regbuf(size, DMA_TO_DEVICE, flags);
-	if (!rb)
-		return false;
-
-	rpcrdma_free_regbuf(req->rl_sendbuf);
-	r_xprt->rx_stats.hardway_register_count += size;
-	req->rl_sendbuf = rb;
-	return true;
-}
-
-/* The rq_rcv_buf is used only if a Reply chunk is necessary.
- * The decision to use a Reply chunk is made later in
- * rpcrdma_marshal_req. This buffer is registered at that time.
- *
- * Otherwise, the associated RPC Reply arrives in a separate
- * Receive buffer, arbitrarily chosen by the HCA. The buffer
- * allocated here for the RPC Reply is not utilized in that
- * case. See rpcrdma_inline_fixup.
- *
- * A regbuf is used here to remember the buffer size.
- */
-static bool
-rpcrdma_get_recvbuf(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req,
-		    size_t size, gfp_t flags)
-{
-	struct rpcrdma_regbuf *rb;
-
-	if (likely(rdmab_length(req->rl_recvbuf) >= size))
-		return true;
-
-	rb = rpcrdma_alloc_regbuf(size, DMA_NONE, flags);
-	if (!rb)
-		return false;
-
-	rpcrdma_free_regbuf(req->rl_recvbuf);
-	r_xprt->rx_stats.hardway_register_count += size;
-	req->rl_recvbuf = rb;
+	if (unlikely(rdmab_length(rb) < size)) {
+		if (!rpcrdma_regbuf_realloc(rb, size, flags))
+			return false;
+		r_xprt->rx_stats.hardway_register_count += size;
+	}
 	return true;
 }
 
@@ -655,9 +618,11 @@ xprt_rdma_allocate(struct rpc_task *task)
 	if (RPC_IS_SWAPPER(task))
 		flags = __GFP_MEMALLOC | GFP_NOWAIT | __GFP_NOWARN;
 
-	if (!rpcrdma_get_sendbuf(r_xprt, req, rqst->rq_callsize, flags))
+	if (!rpcrdma_check_regbuf(r_xprt, req->rl_sendbuf, rqst->rq_callsize,
+				  flags))
 		goto out_fail;
-	if (!rpcrdma_get_recvbuf(r_xprt, req, rqst->rq_rcvsize, flags))
+	if (!rpcrdma_check_regbuf(r_xprt, req->rl_recvbuf, rqst->rq_rcvsize,
+				  flags))
 		goto out_fail;
 
 	rqst->rq_buffer = rdmab_data(req->rl_sendbuf);