3 files changed, 14 insertions, 27 deletions

diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c
index 430f8b5a8c43..b8818c09a621 100644
--- a/net/sunrpc/xprtrdma/rpc_rdma.c
+++ b/net/sunrpc/xprtrdma/rpc_rdma.c
@@ -1244,7 +1244,7 @@ void rpcrdma_complete_rqst(struct rpcrdma_rep *rep)
 out:
 	spin_lock(&xprt->recv_lock);
 	cwnd = xprt->cwnd;
-	xprt->cwnd = atomic_read(&r_xprt->rx_buf.rb_credits) << RPC_CWNDSHIFT;
+	xprt->cwnd = r_xprt->rx_buf.rb_credits << RPC_CWNDSHIFT;
 	if (xprt->cwnd > cwnd)
 		xprt_release_rqst_cong(rqst->rq_task);
 
@@ -1297,8 +1297,10 @@ void rpcrdma_reply_handler(struct rpcrdma_rep *rep)
 {
 	struct rpcrdma_xprt *r_xprt = rep->rr_rxprt;
 	struct rpc_xprt *xprt = &r_xprt->rx_xprt;
+	struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
 	struct rpcrdma_req *req;
 	struct rpc_rqst *rqst;
+	u32 credits;
 	__be32 *p;
 
 	dprintk("RPC:       %s: incoming rep %p\n", __func__, rep);
@@ -1315,7 +1317,7 @@ void rpcrdma_reply_handler(struct rpcrdma_rep *rep)
 		goto out_shortreply;
 	rep->rr_xid = *p++;
 	rep->rr_vers = *p++;
-	p++;	/* credits */
+	credits = be32_to_cpu(*p++);
 	rep->rr_proc = *p++;
 
 	if (rep->rr_vers != rpcrdma_version)
@@ -1332,7 +1334,15 @@ void rpcrdma_reply_handler(struct rpcrdma_rep *rep)
 	if (!rqst)
 		goto out_norqst;
 	xprt_pin_rqst(rqst);
+
+	if (credits == 0)
+		credits = 1;	/* don't deadlock */
+	else if (credits > buf->rb_max_requests)
+		credits = buf->rb_max_requests;
+	buf->rb_credits = credits;
+
 	spin_unlock(&xprt->recv_lock);
+
 	req = rpcr_to_rdmar(rqst);
 	req->rl_reply = rep;
 	rep->rr_rqst = rqst;
diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index d45695408df3..247b00b715c2 100644
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -133,25 +133,6 @@ rpcrdma_wc_send(struct ib_cq *cq, struct ib_wc *wc)
 		       wc->status, wc->vendor_err);
 }
 
-/* Perform basic sanity checking to avoid using garbage
- * to update the credit grant value.
- */
-static void
-rpcrdma_update_granted_credits(struct rpcrdma_rep *rep)
-{
-	struct rpcrdma_buffer *buffer = &rep->rr_rxprt->rx_buf;
-	__be32 *p = rep->rr_rdmabuf->rg_base;
-	u32 credits;
-
-	credits = be32_to_cpup(p + 2);
-	if (credits == 0)
-		credits = 1;	/* don't deadlock */
-	else if (credits > buffer->rb_max_requests)
-		credits = buffer->rb_max_requests;
-
-	atomic_set(&buffer->rb_credits, credits);
-}
-
 /**
  * rpcrdma_wc_receive - Invoked by RDMA provider for each polled Receive WC
  * @cq:	completion queue (ignored)
@@ -181,9 +162,6 @@ rpcrdma_wc_receive(struct ib_cq *cq, struct ib_wc *wc)
 				   rdmab_addr(rep->rr_rdmabuf),
 				   wc->byte_len, DMA_FROM_DEVICE);
 
-	if (wc->byte_len >= RPCRDMA_HDRLEN_ERR)
-		rpcrdma_update_granted_credits(rep);
-
 out_schedule:
 	rpcrdma_reply_handler(rep);
 	return;
@@ -295,7 +273,7 @@ rpcrdma_conn_upcall(struct rdma_cm_id *id, struct rdma_cm_event *event)
 	case RDMA_CM_EVENT_DISCONNECTED:
 		connstate = -ECONNABORTED;
 connected:
-		atomic_set(&xprt->rx_buf.rb_credits, 1);
+		xprt->rx_buf.rb_credits = 1;
 		ep->rep_connected = connstate;
 		rpcrdma_conn_func(ep);
 		wake_up_all(&ep->rep_connect_wait);
@@ -995,7 +973,6 @@ rpcrdma_buffer_create(struct rpcrdma_xprt *r_xprt)
 
 	buf->rb_max_requests = r_xprt->rx_data.max_requests;
 	buf->rb_bc_srv_max_requests = 0;
-	atomic_set(&buf->rb_credits, 1);
 	spin_lock_init(&buf->rb_mwlock);
 	spin_lock_init(&buf->rb_lock);
 	spin_lock_init(&buf->rb_recovery_lock);
diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h
index a85bcd19b37a..0e0ae6195a5b 100644
--- a/net/sunrpc/xprtrdma/xprt_rdma.h
+++ b/net/sunrpc/xprtrdma/xprt_rdma.h
@@ -407,7 +407,7 @@ struct rpcrdma_buffer {
 	struct list_head	rb_send_bufs;
 	struct list_head	rb_recv_bufs;
 	u32			rb_max_requests;
-	atomic_t		rb_credits;	/* most recent credit grant */
+	u32			rb_credits;	/* most recent credit grant */
 
 	u32			rb_bc_srv_max_requests;
 	spinlock_t		rb_reqslock;	/* protect rb_allreqs */