net: Introduce sk_tx_queue_mapping

Introduce sk_tx_queue_mapping; and functions that set, test and
get this value. Reset sk_tx_queue_mapping to -1 whenever the dst
cache is set/reset, and in socket alloc. Setting txq to -1 and
using valid txq=<0 to n-1> allows the tx path to use the value
of sk_tx_queue_mapping directly instead of subtracting 1 on every
tx.

Signed-off-by: Krishna Kumar <krkumar2@in.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 1 deletions

diff --git a/net/core/sock.c b/net/core/sock.c
index 38713aa3faf2..934d9673f084 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -357,6 +357,7 @@ struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
         struct dst_entry *dst = sk->sk_dst_cache;
 
         if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
+                sk_tx_queue_clear(sk);
                 sk->sk_dst_cache = NULL;
                 dst_release(dst);
                 return NULL;
@@ -953,7 +954,8 @@ static void sock_copy(struct sock *nsk, const struct sock *osk)
         void *sptr = nsk->sk_security;
 #endif
         BUILD_BUG_ON(offsetof(struct sock, sk_copy_start) !=
-                     sizeof(osk->sk_node) + sizeof(osk->sk_refcnt));
+                     sizeof(osk->sk_node) + sizeof(osk->sk_refcnt) +
+                     sizeof(osk->sk_tx_queue_mapping));
         memcpy(&nsk->sk_copy_start, &osk->sk_copy_start,
                osk->sk_prot->obj_size - offsetof(struct sock, sk_copy_start));
 #ifdef CONFIG_SECURITY_NETWORK
@@ -997,6 +999,7 @@ static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
 
                 if (!try_module_get(prot->owner))
                         goto out_free_sec;
+                sk_tx_queue_clear(sk);
         }
 
         return sk;