[PATCH] knfsd: convert sk_inuse to atomic_t

Convert the svc_sock->sk_inuse counter from an int protected by
svc_serv->sv_lock, to an atomic.  This reduces the number of places we need to
take the (effectively global) svc_serv->sv_lock.

Signed-off-by: Greg Banks <gnb@melbourne.sgi.com>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/include/linux/sunrpc/svcsock.h b/include/linux/sunrpc/svcsock.h
index 846aee9..17cb834 100644 (file)
--- a/include/linux/sunrpc/svcsock.h
+++ b/include/linux/sunrpc/svcsock.h
@@ -21,7 +21,7 @@ struct svc_sock {
        struct sock *           sk_sk;          /* INET layer */
 
        struct svc_serv *       sk_server;      /* service for this socket */
-       unsigned int            sk_inuse;       /* use count */
+       atomic_t                sk_inuse;       /* use count */
        unsigned long           sk_flags;
 #define        SK_BUSY         0                       /* enqueued/receiving */
 #define        SK_CONN         1                       /* conn pending */

diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index 9ba1a07..d836031 100644 (file)
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -206,7 +206,7 @@ svc_sock_enqueue(struct svc_sock *svsk)
                                "svc_sock_enqueue: server %p, rq_sock=%p!\n",
                                rqstp, rqstp->rq_sock);
                rqstp->rq_sock = svsk;
-               svsk->sk_inuse++;
+               atomic_inc(&svsk->sk_inuse);
                rqstp->rq_reserved = serv->sv_bufsz;
                svsk->sk_reserved += rqstp->rq_reserved;
                wake_up(&rqstp->rq_wait);
@@ -235,7 +235,7 @@ svc_sock_dequeue(struct svc_serv *serv)
        list_del_init(&svsk->sk_ready);
 
        dprintk("svc: socket %p dequeued, inuse=%d\n",
-               svsk->sk_sk, svsk->sk_inuse);
+               svsk->sk_sk, atomic_read(&svsk->sk_inuse));
 
        return svsk;
 }
@@ -285,17 +285,11 @@ void svc_reserve(struct svc_rqst *rqstp, int space)
 static inline void
 svc_sock_put(struct svc_sock *svsk)
 {
-       struct svc_serv *serv = svsk->sk_server;
-
-       spin_lock_bh(&serv->sv_lock);
-       if (!--(svsk->sk_inuse) && test_bit(SK_DEAD, &svsk->sk_flags)) {
-               spin_unlock_bh(&serv->sv_lock);
+       if (atomic_dec_and_test(&svsk->sk_inuse) && test_bit(SK_DEAD, &svsk->sk_flags)) {
                dprintk("svc: releasing dead socket\n");
                sock_release(svsk->sk_sock);
                kfree(svsk);
        }
-       else
-               spin_unlock_bh(&serv->sv_lock);
 }
 
 static void
@@ -897,7 +891,7 @@ svc_tcp_accept(struct svc_sock *svsk)
                                          struct svc_sock,
                                          sk_list);
                        set_bit(SK_CLOSE, &svsk->sk_flags);
-                       svsk->sk_inuse ++;
+                       atomic_inc(&svsk->sk_inuse);
                }
                spin_unlock_bh(&serv->sv_lock);
 
@@ -1229,7 +1223,7 @@ svc_recv(struct svc_rqst *rqstp, long timeout)
        spin_lock_bh(&serv->sv_lock);
        if ((svsk = svc_sock_dequeue(serv)) != NULL) {
                rqstp->rq_sock = svsk;
-               svsk->sk_inuse++;
+               atomic_inc(&svsk->sk_inuse);
                rqstp->rq_reserved = serv->sv_bufsz;    
                svsk->sk_reserved += rqstp->rq_reserved;
        } else {
@@ -1261,7 +1255,7 @@ svc_recv(struct svc_rqst *rqstp, long timeout)
        spin_unlock_bh(&serv->sv_lock);
 
        dprintk("svc: server %p, socket %p, inuse=%d\n",
-                rqstp, svsk, svsk->sk_inuse);
+                rqstp, svsk, atomic_read(&svsk->sk_inuse));
        len = svsk->sk_recvfrom(rqstp);
        dprintk("svc: got len=%d\n", len);
 
@@ -1357,9 +1351,9 @@ svc_age_temp_sockets(unsigned long closure)
 
                if (!test_and_set_bit(SK_OLD, &svsk->sk_flags))
                        continue;
-               if (svsk->sk_inuse || test_bit(SK_BUSY, &svsk->sk_flags))
+               if (atomic_read(&svsk->sk_inuse) || test_bit(SK_BUSY, &svsk->sk_flags))
                        continue;
-               svsk->sk_inuse++;
+               atomic_inc(&svsk->sk_inuse);
                list_move(le, &to_be_aged);
                set_bit(SK_CLOSE, &svsk->sk_flags);
                set_bit(SK_DETACHED, &svsk->sk_flags);
@@ -1420,6 +1414,7 @@ svc_setup_socket(struct svc_serv *serv, struct socket *sock,
        svsk->sk_odata = inet->sk_data_ready;
        svsk->sk_owspace = inet->sk_write_space;
        svsk->sk_server = serv;
+       atomic_set(&svsk->sk_inuse, 0);
        svsk->sk_lastrecv = get_seconds();
        INIT_LIST_HEAD(&svsk->sk_deferred);
        INIT_LIST_HEAD(&svsk->sk_ready);
@@ -1563,7 +1558,7 @@ svc_delete_socket(struct svc_sock *svsk)
                if (test_bit(SK_TEMP, &svsk->sk_flags))
                        serv->sv_tmpcnt--;
 
-       if (!svsk->sk_inuse) {
+       if (!atomic_read(&svsk->sk_inuse)) {
                spin_unlock_bh(&serv->sv_lock);
                if (svsk->sk_sock->file)
                        sockfd_put(svsk->sk_sock);
@@ -1644,10 +1639,8 @@ 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);
        }
-       spin_lock_bh(&rqstp->rq_server->sv_lock);
-       rqstp->rq_sock->sk_inuse++;
+       atomic_inc(&rqstp->rq_sock->sk_inuse);
        dr->svsk = rqstp->rq_sock;
-       spin_unlock_bh(&rqstp->rq_server->sv_lock);
 
        dr->handle.revisit = svc_revisit;
        return &dr->handle;