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>

1 files changed, 2 insertions, 2 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;
 }