ipv4: Optimize flow initialization in fib_validate_source().

Like in commit 44713b67db10c774f14280c129b0d5fd13c70cf2
("ipv4: Optimize flow initialization in output route lookup."
we can optimize the on-stack flow setup to only initialize
the members which are actually used.

Otherwise we bzero the entire structure, then initialize
explicitly the first half of it.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 9 insertions, 7 deletions

diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index 1d2233cd99e6..fe10bcd0f307 100644
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -193,19 +193,21 @@ int fib_validate_source(__be32 src, __be32 dst, u8 tos, int oif,
                         u32 *itag, u32 mark)
 {
         struct in_device *in_dev;
-        struct flowi fl = {
-                .fl4_dst = src,
-                .fl4_src = dst,
-                .fl4_tos = tos,
-                .mark = mark,
-                .iif = oif
-        };
+        struct flowi fl;
         struct fib_result res;
         int no_addr, rpf, accept_local;
         bool dev_match;
         int ret;
         struct net *net;
 
+        fl.oif = 0;
+        fl.iif = oif;
+        fl.mark = mark;
+        fl.fl4_dst = src;
+        fl.fl4_src = dst;
+        fl.fl4_tos = tos;
+        fl.fl4_scope = RT_SCOPE_UNIVERSE;
+
         no_addr = rpf = accept_local = 0;
         in_dev = __in_dev_get_rcu(dev);
         if (in_dev) {