From 5ada552746685d558d0a8e9e979921c75a41e469 Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Thu, 17 Feb 2011 15:29:00 -0800 Subject: [PATCH] ipv4: Simplify output route creation call sequence. There's a lot of redundancy and unnecessary stack frames in the output route creation path. 1) Make __mkroute_output() return error pointers. 2) Eliminate ip_mkroute_output() entirely, made possible by #1. 3) Call __mkroute_output() directly and handling the returning error pointers in ip_route_output_slow(). Signed-off-by: David S. Miller --- net/ipv4/route.c | 58 +++++++++++++++++++----------------------------- 1 file changed, 23 insertions(+), 35 deletions(-) diff --git a/net/ipv4/route.c b/net/ipv4/route.c index 756f5443b5f7..849be48971ec 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -2323,33 +2323,32 @@ skip_cache: EXPORT_SYMBOL(ip_route_input_common); /* called with rcu_read_lock() */ -static int __mkroute_output(struct rtable **result, - struct fib_result *res, - const struct flowi *fl, - const struct flowi *oldflp, - struct net_device *dev_out, - unsigned flags) +static struct rtable *__mkroute_output(struct fib_result *res, + const struct flowi *fl, + const struct flowi *oldflp, + struct net_device *dev_out, + unsigned int flags) { - struct rtable *rth; - struct in_device *in_dev; u32 tos = RT_FL_TOS(oldflp); + struct in_device *in_dev; + struct rtable *rth; if (ipv4_is_loopback(fl->fl4_src) && !(dev_out->flags & IFF_LOOPBACK)) - return -EINVAL; + return ERR_PTR(-EINVAL); if (ipv4_is_lbcast(fl->fl4_dst)) res->type = RTN_BROADCAST; else if (ipv4_is_multicast(fl->fl4_dst)) res->type = RTN_MULTICAST; else if (ipv4_is_zeronet(fl->fl4_dst)) - return -EINVAL; + return ERR_PTR(-EINVAL); if (dev_out->flags & IFF_LOOPBACK) flags |= RTCF_LOCAL; in_dev = __in_dev_get_rcu(dev_out); if (!in_dev) - return -EINVAL; + return ERR_PTR(-EINVAL); if (res->type == RTN_BROADCAST) { flags |= RTCF_BROADCAST | RTCF_LOCAL; @@ -2370,7 +2369,7 @@ static int __mkroute_output(struct rtable **result, rth = dst_alloc(&ipv4_dst_ops); if (!rth) - return -ENOBUFS; + return ERR_PTR(-ENOBUFS); atomic_set(&rth->dst.__refcnt, 1); rth->dst.flags= DST_HOST; @@ -2425,28 +2424,7 @@ static int __mkroute_output(struct rtable **result, rt_set_nexthop(rth, res, 0); rth->rt_flags = flags; - *result = rth; - return 0; -} - -/* called with rcu_read_lock() */ -static int ip_mkroute_output(struct rtable **rp, - struct fib_result *res, - const struct flowi *fl, - const struct flowi *oldflp, - struct net_device *dev_out, - unsigned flags) -{ - struct rtable *rth = NULL; - int err = __mkroute_output(&rth, res, fl, oldflp, dev_out, flags); - unsigned hash; - if (err == 0) { - hash = rt_hash(oldflp->fl4_dst, oldflp->fl4_src, oldflp->oif, - rt_genid(dev_net(dev_out))); - err = rt_intern_hash(hash, rth, rp, NULL, oldflp->oif); - } - - return err; + return rth; } /* @@ -2469,6 +2447,7 @@ static int ip_route_output_slow(struct net *net, struct rtable **rp, struct fib_result res; unsigned int flags = 0; struct net_device *dev_out = NULL; + struct rtable *rth; int err; @@ -2627,7 +2606,16 @@ static int ip_route_output_slow(struct net *net, struct rtable **rp, make_route: - err = ip_mkroute_output(rp, &res, &fl, oldflp, dev_out, flags); + rth = __mkroute_output(&res, &fl, oldflp, dev_out, flags); + if (IS_ERR(rth)) + err = PTR_ERR(rth); + else { + unsigned int hash; + + hash = rt_hash(oldflp->fl4_dst, oldflp->fl4_src, oldflp->oif, + rt_genid(dev_net(dev_out))); + err = rt_intern_hash(hash, rth, rp, NULL, oldflp->oif); + } out: return err; } -- 2.30.2