svc: Add a transport function that checks for write space

[deliverable/linux.git] / net / sunrpc / svcsock.c

diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index 492a1dc544f3bf484c4c257a3acb8224976b459d..2007881a5b26b36f7d662dede53f7bbfe7e087c2 100644 (file)
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -204,22 +204,6 @@ static void svc_release_skb(struct svc_rqst *rqstp)
        }
 }
 
-/*
- * Any space to write?
- */
-static inline unsigned long
-svc_sock_wspace(struct svc_sock *svsk)
-{
-       int wspace;
-
-       if (svsk->sk_sock->type == SOCK_STREAM)
-               wspace = sk_stream_wspace(svsk->sk_sk);
-       else
-               wspace = sock_wspace(svsk->sk_sk);
-
-       return wspace;
-}
-
 /*
  * Queue up a socket with data pending. If there are idle nfsd
  * processes, wake 'em up.
@@ -269,22 +253,24 @@ svc_sock_enqueue(struct svc_sock *svsk)
        BUG_ON(svsk->sk_pool != NULL);
        svsk->sk_pool = pool;
 
-       set_bit(SOCK_NOSPACE, &svsk->sk_sock->flags);
-       if (((atomic_read(&svsk->sk_reserved) + serv->sv_max_mesg)*2
-            > svc_sock_wspace(svsk))
-           && !test_bit(SK_CLOSE, &svsk->sk_flags)
-           && !test_bit(SK_CONN, &svsk->sk_flags)) {
+       /* Handle pending connection */
+       if (test_bit(SK_CONN, &svsk->sk_flags))
+               goto process;
+
+       /* Handle close in-progress */
+       if (test_bit(SK_CLOSE, &svsk->sk_flags))
+               goto process;
+
+       /* Check if we have space to reply to a request */
+       if (!svsk->sk_xprt.xpt_ops->xpo_has_wspace(&svsk->sk_xprt)) {
                /* Don't enqueue while not enough space for reply */
-               dprintk("svc: socket %p  no space, %d*2 > %ld, not enqueued\n",
-                       svsk->sk_sk, atomic_read(&svsk->sk_reserved)+serv->sv_max_mesg,
-                       svc_sock_wspace(svsk));
+               dprintk("svc: no write space, socket %p  not enqueued\n", svsk);
                svsk->sk_pool = NULL;
                clear_bit(SK_BUSY, &svsk->sk_flags);
                goto out_unlock;
        }
-       clear_bit(SOCK_NOSPACE, &svsk->sk_sock->flags);
-
 
+ process:
        if (!list_empty(&pool->sp_threads)) {
                rqstp = list_entry(pool->sp_threads.next,
                                   struct svc_rqst,
@@ -897,6 +883,24 @@ static void svc_udp_prep_reply_hdr(struct svc_rqst *rqstp)
 {
 }
 
+static int svc_udp_has_wspace(struct svc_xprt *xprt)
+{
+       struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
+       struct svc_serv *serv = svsk->sk_server;
+       unsigned long required;
+
+       /*
+        * Set the SOCK_NOSPACE flag before checking the available
+        * sock space.
+        */
+       set_bit(SOCK_NOSPACE, &svsk->sk_sock->flags);
+       required = atomic_read(&svsk->sk_reserved) + serv->sv_max_mesg;
+       if (required*2 > sock_wspace(svsk->sk_sk))
+               return 0;
+       clear_bit(SOCK_NOSPACE, &svsk->sk_sock->flags);
+       return 1;
+}
+
 static struct svc_xprt_ops svc_udp_ops = {
        .xpo_recvfrom = svc_udp_recvfrom,
        .xpo_sendto = svc_udp_sendto,
@@ -904,6 +908,7 @@ static struct svc_xprt_ops svc_udp_ops = {
        .xpo_detach = svc_sock_detach,
        .xpo_free = svc_sock_free,
        .xpo_prep_reply_hdr = svc_udp_prep_reply_hdr,
+       .xpo_has_wspace = svc_udp_has_wspace,
 };
 
 static struct svc_xprt_class svc_udp_class = {
@@ -1366,6 +1371,30 @@ static void svc_tcp_prep_reply_hdr(struct svc_rqst *rqstp)
        svc_putnl(resv, 0);
 }
 
+static int svc_tcp_has_wspace(struct svc_xprt *xprt)
+{
+       struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
+       struct svc_serv *serv = svsk->sk_server;
+       int required;
+       int wspace;
+
+       /*
+        * Set the SOCK_NOSPACE flag before checking the available
+        * sock space.
+        */
+       set_bit(SOCK_NOSPACE, &svsk->sk_sock->flags);
+       required = atomic_read(&svsk->sk_reserved) + serv->sv_max_mesg;
+       wspace = sk_stream_wspace(svsk->sk_sk);
+
+       if (wspace < sk_stream_min_wspace(svsk->sk_sk))
+               return 0;
+       if (required * 2 > wspace)
+               return 0;
+
+       clear_bit(SOCK_NOSPACE, &svsk->sk_sock->flags);
+       return 1;
+}
+
 static struct svc_xprt_ops svc_tcp_ops = {
        .xpo_recvfrom = svc_tcp_recvfrom,
        .xpo_sendto = svc_tcp_sendto,
@@ -1373,6 +1402,7 @@ static struct svc_xprt_ops svc_tcp_ops = {
        .xpo_detach = svc_sock_detach,
        .xpo_free = svc_sock_free,
        .xpo_prep_reply_hdr = svc_tcp_prep_reply_hdr,
+       .xpo_has_wspace = svc_tcp_has_wspace,
 };
 
 static struct svc_xprt_class svc_tcp_class = {