Merge branch 'simplify_PRT' into release

[pandora-kernel.git] / net / sunrpc / svc_xprt.c

diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
index bf5b5cd..e588df5 100644 (file)
--- a/net/sunrpc/svc_xprt.c
+++ b/net/sunrpc/svc_xprt.c
@@ -440,7 +440,7 @@ void svc_reserve(struct svc_rqst *rqstp, int space)
                svc_xprt_enqueue(xprt);
        }
 }
-EXPORT_SYMBOL(svc_reserve);
+EXPORT_SYMBOL_GPL(svc_reserve);
 
 static void svc_xprt_release(struct svc_rqst *rqstp)
 {
@@ -448,6 +448,9 @@ static void svc_xprt_release(struct svc_rqst *rqstp)
 
        rqstp->rq_xprt->xpt_ops->xpo_release_rqst(rqstp);
 
+       kfree(rqstp->rq_deferred);
+       rqstp->rq_deferred = NULL;
+
        svc_free_res_pages(rqstp);
        rqstp->rq_res.page_len = 0;
        rqstp->rq_res.page_base = 0;
@@ -498,7 +501,7 @@ void svc_wake_up(struct svc_serv *serv)
                spin_unlock_bh(&pool->sp_lock);
        }
 }
-EXPORT_SYMBOL(svc_wake_up);
+EXPORT_SYMBOL_GPL(svc_wake_up);
 
 int svc_port_is_privileged(struct sockaddr *sin)
 {
@@ -515,8 +518,10 @@ int svc_port_is_privileged(struct sockaddr *sin)
 }
 
 /*
- * Make sure that we don't have too many active connections.  If we
- * have, something must be dropped.
+ * Make sure that we don't have too many active connections. If we have,
+ * something must be dropped. It's not clear what will happen if we allow
+ * "too many" connections, but when dealing with network-facing software,
+ * we have to code defensively. Here we do that by imposing hard limits.
  *
  * There's no point in trying to do random drop here for DoS
  * prevention. The NFS clients does 1 reconnect in 15 seconds. An
@@ -525,19 +530,27 @@ int svc_port_is_privileged(struct sockaddr *sin)
  * The only somewhat efficient mechanism would be if drop old
  * connections from the same IP first. But right now we don't even
  * record the client IP in svc_sock.
+ *
+ * single-threaded services that expect a lot of clients will probably
+ * need to set sv_maxconn to override the default value which is based
+ * on the number of threads
  */
 static void svc_check_conn_limits(struct svc_serv *serv)
 {
-       if (serv->sv_tmpcnt > (serv->sv_nrthreads+3)*20) {
+       unsigned int limit = serv->sv_maxconn ? serv->sv_maxconn :
+                               (serv->sv_nrthreads+3) * 20;
+
+       if (serv->sv_tmpcnt > limit) {
                struct svc_xprt *xprt = NULL;
                spin_lock_bh(&serv->sv_lock);
                if (!list_empty(&serv->sv_tempsocks)) {
                        if (net_ratelimit()) {
                                /* Try to help the admin */
                                printk(KERN_NOTICE "%s: too many open  "
-                                      "connections, consider increasing the "
-                                      "number of nfsd threads\n",
-                                      serv->sv_name);
+                                      "connections, consider increasing %s\n",
+                                      serv->sv_name, serv->sv_maxconn ?
+                                      "the max number of connections." :
+                                      "the number of threads.");
                        }
                        /*
                         * Always select the oldest connection. It's not fair,
@@ -730,7 +743,7 @@ int svc_recv(struct svc_rqst *rqstp, long timeout)
                serv->sv_stats->netcnt++;
        return len;
 }
-EXPORT_SYMBOL(svc_recv);
+EXPORT_SYMBOL_GPL(svc_recv);
 
 /*
  * Drop request
@@ -740,7 +753,7 @@ void svc_drop(struct svc_rqst *rqstp)
        dprintk("svc: xprt %p dropped request\n", rqstp->rq_xprt);
        svc_xprt_release(rqstp);
 }
-EXPORT_SYMBOL(svc_drop);
+EXPORT_SYMBOL_GPL(svc_drop);
 
 /*
  * Return reply to client.
@@ -837,6 +850,11 @@ static void svc_age_temp_xprts(unsigned long closure)
 void svc_delete_xprt(struct svc_xprt *xprt)
 {
        struct svc_serv *serv = xprt->xpt_server;
+       struct svc_deferred_req *dr;
+
+       /* Only do this once */
+       if (test_and_set_bit(XPT_DEAD, &xprt->xpt_flags))
+               return;
 
        dprintk("svc: svc_delete_xprt(%p)\n", xprt);
        xprt->xpt_ops->xpo_detach(xprt);
@@ -851,12 +869,16 @@ void svc_delete_xprt(struct svc_xprt *xprt)
         * while still attached to a queue, the queue itself
         * is about to be destroyed (in svc_destroy).
         */
-       if (!test_and_set_bit(XPT_DEAD, &xprt->xpt_flags)) {
-               BUG_ON(atomic_read(&xprt->xpt_ref.refcount) < 2);
-               if (test_bit(XPT_TEMP, &xprt->xpt_flags))
-                       serv->sv_tmpcnt--;
+       if (test_bit(XPT_TEMP, &xprt->xpt_flags))
+               serv->sv_tmpcnt--;
+
+       for (dr = svc_deferred_dequeue(xprt); dr;
+            dr = svc_deferred_dequeue(xprt)) {
                svc_xprt_put(xprt);
+               kfree(dr);
        }
+
+       svc_xprt_put(xprt);
        spin_unlock_bh(&serv->sv_lock);
 }
 
@@ -902,17 +924,19 @@ static void svc_revisit(struct cache_deferred_req *dreq, int too_many)
                container_of(dreq, struct svc_deferred_req, handle);
        struct svc_xprt *xprt = dr->xprt;
 
-       if (too_many) {
+       spin_lock(&xprt->xpt_lock);
+       set_bit(XPT_DEFERRED, &xprt->xpt_flags);
+       if (too_many || test_bit(XPT_DEAD, &xprt->xpt_flags)) {
+               spin_unlock(&xprt->xpt_lock);
+               dprintk("revisit canceled\n");
                svc_xprt_put(xprt);
                kfree(dr);
                return;
        }
        dprintk("revisit queued\n");
        dr->xprt = NULL;
-       spin_lock(&xprt->xpt_lock);
        list_add(&dr->handle.recent, &xprt->xpt_deferred);
        spin_unlock(&xprt->xpt_lock);
-       set_bit(XPT_DEFERRED, &xprt->xpt_flags);
        svc_xprt_enqueue(xprt);
        svc_xprt_put(xprt);
 }