ipv4: __mkroute_output() speedup

[net-next-2.6.git] / net / ipv4 / route.c

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 98beda47bc99f798c1803c29ccede8f2c1d67ef7..ea895004caf3c120df4a2ace7af1241604264cab 100644 (file)
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -2358,9 +2358,8 @@ static int __mkroute_output(struct rtable **result,
        struct rtable *rth;
        struct in_device *in_dev;
        u32 tos = RT_FL_TOS(oldflp);
-       int err = 0;
 
-       if (ipv4_is_loopback(fl->fl4_src) && !(dev_out->flags&IFF_LOOPBACK))
+       if (ipv4_is_loopback(fl->fl4_src) && !(dev_out->flags & IFF_LOOPBACK))
                return -EINVAL;
 
        if (fl->fl4_dst == htonl(0xFFFFFFFF))
@@ -2373,11 +2372,12 @@ static int __mkroute_output(struct rtable **result,
        if (dev_out->flags & IFF_LOOPBACK)
                flags |= RTCF_LOCAL;
 
-       /* get work reference to inet device */
-       in_dev = in_dev_get(dev_out);
-       if (!in_dev)
+       rcu_read_lock();
+       in_dev = __in_dev_get_rcu(dev_out);
+       if (!in_dev) {
+               rcu_read_unlock();
                return -EINVAL;
-
+       }
        if (res->type == RTN_BROADCAST) {
                flags |= RTCF_BROADCAST | RTCF_LOCAL;
                if (res->fi) {
@@ -2385,13 +2385,13 @@ static int __mkroute_output(struct rtable **result,
                        res->fi = NULL;
                }
        } else if (res->type == RTN_MULTICAST) {
-               flags |= RTCF_MULTICAST|RTCF_LOCAL;
+               flags |= RTCF_MULTICAST | RTCF_LOCAL;
                if (!ip_check_mc(in_dev, oldflp->fl4_dst, oldflp->fl4_src,
                                 oldflp->proto))
                        flags &= ~RTCF_LOCAL;
                /* If multicast route do not exist use
-                  default one, but do not gateway in this case.
-                  Yes, it is hack.
+                * default one, but do not gateway in this case.
+                * Yes, it is hack.
                 */
                if (res->fi && res->prefixlen < 4) {
                        fib_info_put(res->fi);
@@ -2402,9 +2402,12 @@ static int __mkroute_output(struct rtable **result,
 
        rth = dst_alloc(&ipv4_dst_ops);
        if (!rth) {
-               err = -ENOBUFS;
-               goto cleanup;
+               rcu_read_unlock();
+               return -ENOBUFS;
        }
+       in_dev_hold(in_dev);
+       rcu_read_unlock();
+       rth->idev = in_dev;
 
        atomic_set(&rth->dst.__refcnt, 1);
        rth->dst.flags= DST_HOST;
@@ -2425,7 +2428,6 @@ static int __mkroute_output(struct rtable **result,
           cache entry */
        rth->dst.dev    = dev_out;
        dev_hold(dev_out);
-       rth->idev       = in_dev_get(dev_out);
        rth->rt_gateway = fl->fl4_dst;
        rth->rt_spec_dst= fl->fl4_src;
 
@@ -2460,13 +2462,8 @@ static int __mkroute_output(struct rtable **result,
        rt_set_nexthop(rth, res, 0);
 
        rth->rt_flags = flags;
-
        *result = rth;
- cleanup:
-       /* release work reference to inet device */
-       in_dev_put(in_dev);
-
-       return err;
+       return 0;
 }
 
 static int ip_mkroute_output(struct rtable **rp,