svc: Change svc_sock_received to svc_xprt_received and export it

All fields touched by svc_sock_received are now transport independent.
Change it to use svc_xprt directly. This function is called from
transport dependent code, so export it.

Update the comment to clearly state the rules for calling this function.
Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
Acked-by: Neil Brown <neilb@suse.de>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Greg Banks <gnb@sgi.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

include/linux/sunrpc/svc_xprt.h

@@ -62,8 +62,8 @@ void	svc_unreg_xprt_class(struct svc_xprt_class *);
 void	svc_xprt_init(struct svc_xprt_class *, struct svc_xprt *,
 		      struct svc_serv *);
 int	svc_create_xprt(struct svc_serv *, char *, unsigned short, int);
+void	svc_xprt_received(struct svc_xprt *);
 void	svc_xprt_put(struct svc_xprt *xprt);
-
 static inline void svc_xprt_get(struct svc_xprt *xprt)
 {
 	kref_get(&xprt->xpt_ref);

net/sunrpc/svcsock.c

@@ -325,19 +325,21 @@ svc_sock_dequeue(struct svc_pool *pool)
 }
 
 /*
- * Having read something from a socket, check whether it
- * needs to be re-enqueued.
- * Note: XPT_DATA only gets cleared when a read-attempt finds
- * no (or insufficient) data.
+ * svc_xprt_received conditionally queues the transport for processing
+ * by another thread. The caller must hold the XPT_BUSY bit and must
+ * not thereafter touch transport data.
+ *
+ * Note: XPT_DATA only gets cleared when a read-attempt finds no (or
+ * insufficient) data.
  */
-static inline void
-svc_sock_received(struct svc_sock *svsk)
+void svc_xprt_received(struct svc_xprt *xprt)
 {
-	svsk->sk_xprt.xpt_pool = NULL;
-	clear_bit(XPT_BUSY, &svsk->sk_xprt.xpt_flags);
-	svc_xprt_enqueue(&svsk->sk_xprt);
+	BUG_ON(!test_bit(XPT_BUSY, &xprt->xpt_flags));
+	xprt->xpt_pool = NULL;
+	clear_bit(XPT_BUSY, &xprt->xpt_flags);
+	svc_xprt_enqueue(xprt);
 }
-
+EXPORT_SYMBOL_GPL(svc_xprt_received);
 
 /**
  * svc_reserve - change the space reserved for the reply to a request.
@@ -766,7 +768,7 @@ svc_udp_recvfrom(struct svc_rqst *rqstp)
 				(serv->sv_nrthreads+3) * serv->sv_max_mesg);
 
 	if ((rqstp->rq_deferred = svc_deferred_dequeue(svsk))) {
-		svc_sock_received(svsk);
+		svc_xprt_received(&svsk->sk_xprt);
 		return svc_deferred_recv(rqstp);
 	}
 
@@ -783,7 +785,7 @@ svc_udp_recvfrom(struct svc_rqst *rqstp)
 			dprintk("svc: recvfrom returned error %d\n", -err);
 			set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
 		}
-		svc_sock_received(svsk);
+		svc_xprt_received(&svsk->sk_xprt);
 		return -EAGAIN;
 	}
 	rqstp->rq_addrlen = sizeof(rqstp->rq_addr);
@@ -798,7 +800,7 @@ svc_udp_recvfrom(struct svc_rqst *rqstp)
 	/*
 	 * Maybe more packets - kick another thread ASAP.
 	 */
-	svc_sock_received(svsk);
+	svc_xprt_received(&svsk->sk_xprt);
 
 	len  = skb->len - sizeof(struct udphdr);
 	rqstp->rq_arg.len = len;
@@ -1104,7 +1106,7 @@ static struct svc_xprt *svc_tcp_accept(struct svc_xprt *xprt)
 	}
 	memcpy(&newsvsk->sk_local, sin, slen);
 
-	svc_sock_received(newsvsk);
+	svc_xprt_received(&newsvsk->sk_xprt);
 
 	if (serv->sv_stats)
 		serv->sv_stats->nettcpconn++;
@@ -1134,7 +1136,7 @@ svc_tcp_recvfrom(struct svc_rqst *rqstp)
 		test_bit(XPT_CLOSE, &svsk->sk_xprt.xpt_flags));
 
 	if ((rqstp->rq_deferred = svc_deferred_dequeue(svsk))) {
-		svc_sock_received(svsk);
+		svc_xprt_received(&svsk->sk_xprt);
 		return svc_deferred_recv(rqstp);
 	}
 
@@ -1174,7 +1176,7 @@ svc_tcp_recvfrom(struct svc_rqst *rqstp)
 		if (len < want) {
 			dprintk("svc: short recvfrom while reading record length (%d of %lu)\n",
 				len, want);
-			svc_sock_received(svsk);
+			svc_xprt_received(&svsk->sk_xprt);
 			return -EAGAIN; /* record header not complete */
 		}
 
@@ -1210,7 +1212,7 @@ svc_tcp_recvfrom(struct svc_rqst *rqstp)
 	if (len < svsk->sk_reclen) {
 		dprintk("svc: incomplete TCP record (%d of %d)\n",
 			len, svsk->sk_reclen);
-		svc_sock_received(svsk);
+		svc_xprt_received(&svsk->sk_xprt);
 		return -EAGAIN;	/* record not complete */
 	}
 	len = svsk->sk_reclen;
@@ -1250,7 +1252,7 @@ svc_tcp_recvfrom(struct svc_rqst *rqstp)
 	svsk->sk_reclen = 0;
 	svsk->sk_tcplen = 0;
 
-	svc_sock_received(svsk);
+	svc_xprt_received(&svsk->sk_xprt);
 	if (serv->sv_stats)
 		serv->sv_stats->nettcpcnt++;
 
@@ -1263,7 +1265,7 @@ svc_tcp_recvfrom(struct svc_rqst *rqstp)
  error:
 	if (len == -EAGAIN) {
 		dprintk("RPC: TCP recvfrom got EAGAIN\n");
-		svc_sock_received(svsk);
+		svc_xprt_received(&svsk->sk_xprt);
 	} else {
 		printk(KERN_NOTICE "%s: recvfrom returned errno %d\n",
 		       svsk->sk_xprt.xpt_server->sv_name, -len);
@@ -1590,7 +1592,7 @@ svc_recv(struct svc_rqst *rqstp, long timeout)
 			__module_get(newxpt->xpt_class->xcl_owner);
 			svc_check_conn_limits(svsk->sk_xprt.xpt_server);
 		}
-		svc_sock_received(svsk);
+		svc_xprt_received(&svsk->sk_xprt);
 	} else {
 		dprintk("svc: server %p, pool %u, socket %p, inuse=%d\n",
 			rqstp, pool->sp_id, svsk,
@@ -1809,7 +1811,7 @@ int svc_addsock(struct svc_serv *serv,
 	else {
 		svsk = svc_setup_socket(serv, so, &err, SVC_SOCK_DEFAULTS);
 		if (svsk) {
-			svc_sock_received(svsk);
+			svc_xprt_received(&svsk->sk_xprt);
 			err = 0;
 		}
 	}
@@ -1865,7 +1867,7 @@ static struct svc_xprt *svc_create_socket(struct svc_serv *serv,
 	}
 
 	if ((svsk = svc_setup_socket(serv, sock, &error, flags)) != NULL) {
-		svc_sock_received(svsk);
+		svc_xprt_received(&svsk->sk_xprt);
 		return (struct svc_xprt *)svsk;
 	}