[ofa-general] [RFC,PATCH 10/20] svc: Add generic refcount services

[Tom Tucker]

Add inline svc_sock_get() so that service transport code will not
need to manipulate sk_inuse directly.  Also, make svc_sock_put()
available so that transport code outside svcsock.c can use it.

Signed-off-by: Greg Banks <gnb at melbourne.sgi.com>
Signed-off-by: Tom Tucker <tom at opengridcomputing.com>
---

 include/linux/sunrpc/svcsock.h |   15 +++++++++++++++
 net/sunrpc/svcsock.c           |   29 ++++++++++++++---------------
 2 files changed, 29 insertions(+), 15 deletions(-)

diff --git a/include/linux/sunrpc/svcsock.h b/include/linux/sunrpc/svcsock.h
index ea8b62b..9f37f30 100644
--- a/include/linux/sunrpc/svcsock.h
+++ b/include/linux/sunrpc/svcsock.h
@@ -115,6 +115,7 @@ int		svc_addsock(struct svc_serv *serv,
 			    int *proto);
 void		svc_sock_enqueue(struct svc_sock *svsk);
 void		svc_sock_received(struct svc_sock *svsk);
+void	    	__svc_sock_put(struct svc_sock *svsk);
 
 /*
  * svc_makesock socket characteristics
@@ -123,4 +124,18 @@ #define SVC_SOCK_DEFAULTS	(0U)
 #define SVC_SOCK_ANONYMOUS	(1U << 0)	/* don't register with pmap */
 #define SVC_SOCK_TEMPORARY	(1U << 1)	/* flag socket as temporary */
 
+/*
+ * Take and drop a temporary reference count on the svc_sock.
+ */
+static inline void svc_sock_get(struct svc_sock *svsk)
+{
+	atomic_inc(&svsk->sk_inuse);
+}
+
+static inline void svc_sock_put(struct svc_sock *svsk)
+{
+	if (atomic_dec_and_test(&svsk->sk_inuse))
+	    __svc_sock_put(svsk);
+}
+
 #endif /* SUNRPC_SVCSOCK_H */
diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index dcb5c7a..02f682a 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -273,7 +273,7 @@ svc_sock_enqueue(struct svc_sock *svsk)
 				"svc_sock_enqueue: server %p, rq_sock=%p!\n",
 				rqstp, rqstp->rq_sock);
 		rqstp->rq_sock = svsk;
-		atomic_inc(&svsk->sk_inuse);
+		svc_sock_get(svsk);
 		rqstp->rq_reserved = serv->sv_max_mesg;
 		atomic_add(rqstp->rq_reserved, &svsk->sk_reserved);
 		BUG_ON(svsk->sk_pool != pool);
@@ -351,17 +351,16 @@ void svc_reserve(struct svc_rqst *rqstp,
 /*
  * Release a socket after use.
  */
-static inline void
-svc_sock_put(struct svc_sock *svsk)
+void
+__svc_sock_put(struct svc_sock *svsk)
 {
-	if (atomic_dec_and_test(&svsk->sk_inuse)) {
-		BUG_ON(! test_bit(SK_DEAD, &svsk->sk_flags));
+	BUG_ON(! test_bit(SK_DEAD, &svsk->sk_flags));
 
-		if (svsk->sk_info_authunix != NULL)
-			svcauth_unix_info_release(svsk->sk_info_authunix);
-    	    	svsk->sk_xprt->xpt_free(svsk);
-	}
+	if (svsk->sk_info_authunix != NULL)
+		svcauth_unix_info_release(svsk->sk_info_authunix);
+	svsk->sk_xprt->xpt_free(svsk);
 }
+EXPORT_SYMBOL_GPL(__svc_sock_put);
 
 static void
 svc_sock_release(struct svc_rqst *rqstp)
@@ -1109,7 +1108,7 @@ svc_tcp_accept(struct svc_sock *svsk)
 					  struct svc_sock,
 					  sk_list);
 			set_bit(SK_CLOSE, &svsk->sk_flags);
-			atomic_inc(&svsk->sk_inuse);
+			svc_sock_get(svsk);
 		}
 		spin_unlock_bh(&serv->sv_lock);
 
@@ -1481,7 +1480,7 @@ svc_recv(struct svc_rqst *rqstp, long ti
 	spin_lock_bh(&pool->sp_lock);
 	if ((svsk = svc_sock_dequeue(pool)) != NULL) {
 		rqstp->rq_sock = svsk;
-		atomic_inc(&svsk->sk_inuse);
+		svc_sock_get(svsk);
 		rqstp->rq_reserved = serv->sv_max_mesg;
 		atomic_add(rqstp->rq_reserved, &svsk->sk_reserved);
 	} else {
@@ -1620,7 +1619,7 @@ svc_age_temp_sockets(unsigned long closu
 			continue;
 		if (atomic_read(&svsk->sk_inuse) || test_bit(SK_BUSY, &svsk->sk_flags))
 			continue;
-		atomic_inc(&svsk->sk_inuse);
+		svc_sock_get(svsk);
 		list_move(le, &to_be_aged);
 		set_bit(SK_CLOSE, &svsk->sk_flags);
 		set_bit(SK_DETACHED, &svsk->sk_flags);
@@ -1868,7 +1867,7 @@ svc_delete_socket(struct svc_sock *svsk)
 	 */
 	if (!test_and_set_bit(SK_DEAD, &svsk->sk_flags)) {
 		BUG_ON(atomic_read(&svsk->sk_inuse)<2);
-		atomic_dec(&svsk->sk_inuse);
+		svc_sock_put(svsk);
 		if (test_bit(SK_TEMP, &svsk->sk_flags))
 			serv->sv_tmpcnt--;
 	}
@@ -1883,7 +1882,7 @@ static void svc_close_socket(struct svc_
 		/* someone else will have to effect the close */
 		return;
 
-	atomic_inc(&svsk->sk_inuse);
+	svc_sock_get(svsk);
 	svc_delete_socket(svsk);
 	clear_bit(SK_BUSY, &svsk->sk_flags);
 	svc_sock_put(svsk);
@@ -1976,7 +1975,7 @@ svc_defer(struct cache_req *req)
 		dr->argslen = rqstp->rq_arg.len >> 2;
 		memcpy(dr->args, rqstp->rq_arg.head[0].iov_base-skip, dr->argslen<<2);
 	}
-	atomic_inc(&rqstp->rq_sock->sk_inuse);
+	svc_sock_get(rqstp->rq_sock);
 	dr->svsk = rqstp->rq_sock;
 
 	dr->handle.revisit = svc_revisit;