ipv6: replace write lock with read lock when get route info

geting route info does not write rt->rt6i_table, so replace
write lock with read lock

Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Li RongQing <roy.qing.li@gmail.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 6 insertions, 6 deletions

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 5fd8ec895c8b..719a828fb67f 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -1708,7 +1708,7 @@ static struct rt6_info *addrconf_get_prefix_route(const struct in6_addr *pfx,
         if (table == NULL)
                 return NULL;
 
-        write_lock_bh(&table->tb6_lock);
+        read_lock_bh(&table->tb6_lock);
         fn = fib6_locate(&table->tb6_root, pfx, plen, NULL, 0);
         if (!fn)
                 goto out;
@@ -1723,7 +1723,7 @@ static struct rt6_info *addrconf_get_prefix_route(const struct in6_addr *pfx,
                 break;
         }
 out:
-        write_unlock_bh(&table->tb6_lock);
+        read_unlock_bh(&table->tb6_lock);
         return rt;
 }
 
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index f568ac697987..83dafa528936 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1837,7 +1837,7 @@ static struct rt6_info *rt6_get_route_info(struct net *net,
         if (!table)
                 return NULL;
 
-        write_lock_bh(&table->tb6_lock);
+        read_lock_bh(&table->tb6_lock);
         fn = fib6_locate(&table->tb6_root, prefix ,prefixlen, NULL, 0);
         if (!fn)
                 goto out;
@@ -1853,7 +1853,7 @@ static struct rt6_info *rt6_get_route_info(struct net *net,
                 break;
         }
 out:
-        write_unlock_bh(&table->tb6_lock);
+        read_unlock_bh(&table->tb6_lock);
         return rt;
 }
 
@@ -1896,7 +1896,7 @@ struct rt6_info *rt6_get_dflt_router(const struct in6_addr *addr, struct net_dev
         if (!table)
                 return NULL;
 
-        write_lock_bh(&table->tb6_lock);
+        read_lock_bh(&table->tb6_lock);
         for (rt = table->tb6_root.leaf; rt; rt=rt->dst.rt6_next) {
                 if (dev == rt->dst.dev &&
                     ((rt->rt6i_flags & (RTF_ADDRCONF | RTF_DEFAULT)) == (RTF_ADDRCONF | RTF_DEFAULT)) &&
@@ -1905,7 +1905,7 @@ struct rt6_info *rt6_get_dflt_router(const struct in6_addr *addr, struct net_dev
         }
         if (rt)
                 dst_hold(&rt->dst);
-        write_unlock_bh(&table->tb6_lock);
+        read_unlock_bh(&table->tb6_lock);
         return rt;
 }