net: mpls: Remove rcu protection from nh_dev

Following the previous commit, nh_dev can no longer be accessed and
modified concurrently.

Signed-off-by: Benjamin Poirier <bpoirier@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c
index 6e587feb705c4e5e49dc415cd7c51b1b7f0c5752..0c7bde1c14a6a879a3263fae3390720c796a3610 100644 (file)
--- a/net/mpls/af_mpls.c
+++ b/net/mpls/af_mpls.c
@@ -409,7 +409,7 @@ static int mpls_forward(struct sk_buff *skb, struct net_device *dev,
                goto err;
 
        /* Find the output device */
-       out_dev = rcu_dereference(nh->nh_dev);
+       out_dev = nh->nh_dev;
        if (!mpls_output_possible(out_dev))
                goto tx_err;
 
@@ -698,7 +698,7 @@ static int mpls_nh_assign_dev(struct net *net, struct mpls_route *rt,
            (dev->addr_len != nh->nh_via_alen))
                goto errout;
 
-       RCU_INIT_POINTER(nh->nh_dev, dev);
+       nh->nh_dev = dev;
 
        if (!(dev->flags & IFF_UP)) {
                nh->nh_flags |= RTNH_F_DEAD;
@@ -1510,12 +1510,9 @@ static int mpls_ifdown(struct net_device *dev, int event)
                        u8 deleted = 0;
 
                        for_nexthops(rt) {
-                               struct net_device *nh_dev =
-                                       rtnl_dereference(nh->nh_dev);
-
-                               if (!nh_dev || nh_dev == dev)
+                               if (!nh->nh_dev || nh->nh_dev == dev)
                                        deleted++;
-                               if (nh_dev == dev)
+                               if (nh->nh_dev == dev)
                                        nh_del = true;
                        } endfor_nexthops(rt);
 
@@ -1540,7 +1537,7 @@ static int mpls_ifdown(struct net_device *dev, int event)
                change_nexthops(rt) {
                        unsigned int nh_flags = nh->nh_flags;
 
-                       if (rtnl_dereference(nh->nh_dev) != dev)
+                       if (nh->nh_dev != dev)
                                goto next;
 
                        switch (event) {
@@ -1553,7 +1550,7 @@ static int mpls_ifdown(struct net_device *dev, int event)
                                break;
                        }
                        if (event == NETDEV_UNREGISTER)
-                               RCU_INIT_POINTER(nh->nh_dev, NULL);
+                               nh->nh_dev = NULL;
 
                        if (nh->nh_flags != nh_flags)
                                WRITE_ONCE(nh->nh_flags, nh_flags);
@@ -1588,14 +1585,12 @@ static void mpls_ifup(struct net_device *dev, unsigned int flags)
                alive = 0;
                change_nexthops(rt) {
                        unsigned int nh_flags = nh->nh_flags;
-                       struct net_device *nh_dev =
-                               rtnl_dereference(nh->nh_dev);
 
                        if (!(nh_flags & flags)) {
                                alive++;
                                continue;
                        }
-                       if (nh_dev != dev)
+                       if (nh->nh_dev != dev)
                                continue;
                        alive++;
                        nh_flags &= ~flags;
@@ -2030,7 +2025,7 @@ static int mpls_dump_route(struct sk_buff *skb, u32 portid, u32 seq, int event,
                    nla_put_via(skb, nh->nh_via_table, mpls_nh_via(rt, nh),
                                nh->nh_via_alen))
                        goto nla_put_failure;
-               dev = rtnl_dereference(nh->nh_dev);
+               dev = nh->nh_dev;
                if (dev && nla_put_u32(skb, RTA_OIF, dev->ifindex))
                        goto nla_put_failure;
                if (nh->nh_flags & RTNH_F_LINKDOWN)
@@ -2048,7 +2043,7 @@ static int mpls_dump_route(struct sk_buff *skb, u32 portid, u32 seq, int event,
                        goto nla_put_failure;
 
                for_nexthops(rt) {
-                       dev = rtnl_dereference(nh->nh_dev);
+                       dev = nh->nh_dev;
                        if (!dev)
                                continue;
 
@@ -2159,18 +2154,14 @@ static int mpls_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh,
 static bool mpls_rt_uses_dev(struct mpls_route *rt,
                             const struct net_device *dev)
 {
-       struct net_device *nh_dev;
-
        if (rt->rt_nhn == 1) {
                struct mpls_nh *nh = rt->rt_nh;
 
-               nh_dev = rtnl_dereference(nh->nh_dev);
-               if (dev == nh_dev)
+               if (nh->nh_dev == dev)
                        return true;
        } else {
                for_nexthops(rt) {
-                       nh_dev = rtnl_dereference(nh->nh_dev);
-                       if (nh_dev == dev)
+                       if (nh->nh_dev == dev)
                                return true;
                } endfor_nexthops(rt);
        }
@@ -2258,7 +2249,7 @@ static inline size_t lfib_nlmsg_size(struct mpls_route *rt)
                size_t nhsize = 0;
 
                for_nexthops(rt) {
-                       if (!rtnl_dereference(nh->nh_dev))
+                       if (!nh->nh_dev)
                                continue;
                        nhsize += nla_total_size(sizeof(struct rtnexthop));
                        /* RTA_VIA */
@@ -2504,7 +2495,7 @@ static int mpls_getroute(struct sk_buff *in_skb, struct nlmsghdr *in_nlh,
            nla_put_via(skb, nh->nh_via_table, mpls_nh_via(rt, nh),
                        nh->nh_via_alen))
                goto nla_put_failure;
-       dev = rtnl_dereference(nh->nh_dev);
+       dev = nh->nh_dev;
        if (dev && nla_put_u32(skb, RTA_OIF, dev->ifindex))
                goto nla_put_failure;
 
@@ -2543,7 +2534,7 @@ static int resize_platform_label_table(struct net *net, size_t limit)
                rt0 = mpls_rt_alloc(1, lo->addr_len, 0);
                if (IS_ERR(rt0))
                        goto nort0;
-               RCU_INIT_POINTER(rt0->rt_nh->nh_dev, lo);
+               rt0->rt_nh->nh_dev = lo;
                rt0->rt_protocol = RTPROT_KERNEL;
                rt0->rt_payload_type = MPT_IPV4;
                rt0->rt_ttl_propagate = MPLS_TTL_PROP_DEFAULT;
@@ -2557,7 +2548,7 @@ static int resize_platform_label_table(struct net *net, size_t limit)
                rt2 = mpls_rt_alloc(1, lo->addr_len, 0);
                if (IS_ERR(rt2))
                        goto nort2;
-               RCU_INIT_POINTER(rt2->rt_nh->nh_dev, lo);
+               rt2->rt_nh->nh_dev = lo;
                rt2->rt_protocol = RTPROT_KERNEL;
                rt2->rt_payload_type = MPT_IPV6;
                rt2->rt_ttl_propagate = MPLS_TTL_PROP_DEFAULT;

diff --git a/net/mpls/internal.h b/net/mpls/internal.h
index 838cdfc10e47d6efd51a7f89c674458f845e6a44..893df00b77b62ec8a6c5a85dd37679a2210fce73 100644 (file)
--- a/net/mpls/internal.h
+++ b/net/mpls/internal.h
@@ -87,7 +87,7 @@ enum mpls_payload_type {
 };
 
 struct mpls_nh { /* next hop label forwarding entry */
-       struct net_device __rcu *nh_dev;
+       struct net_device       *nh_dev;
 
        /* nh_flags is accessed under RCU in the packet path; it is
         * modified handling netdev events with rtnl lock held