mptcp: create msk early

This change moves the mptcp socket allocation from mptcp_accept() to
subflow_syn_recv_sock(), so that subflow->conn is now always set
for the non fallback scenario.

It allows cleaning up a bit mptcp_accept() reducing the additional
locking and will allow fourther cleanup in the next patch.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 29 deletions

diff --git a/net/mptcp/token.c b/net/mptcp/token.c
index 84d887806090..b71b53c0ac8d 100644
--- a/net/mptcp/token.c
+++ b/net/mptcp/token.c
@@ -128,46 +128,19 @@ int mptcp_token_new_connect(struct sock *sk)
  *
  * Called when a SYN packet creates a new logical connection, i.e.
  * is not a join request.
- *
- * We don't have an mptcp socket yet at that point.
- * This is paired with mptcp_token_update_accept, called on accept().
  */
-int mptcp_token_new_accept(u32 token)
+int mptcp_token_new_accept(u32 token, struct sock *conn)
 {
 	int err;
 
 	spin_lock_bh(&token_tree_lock);
-	err = radix_tree_insert(&token_tree, token, &token_used);
+	err = radix_tree_insert(&token_tree, token, conn);
 	spin_unlock_bh(&token_tree_lock);
 
 	return err;
 }
 
 /**
- * mptcp_token_update_accept - update token to map to mptcp socket
- * @conn: the new struct mptcp_sock
- * @sk: the initial subflow for this mptcp socket
- *
- * Called when the first mptcp socket is created on accept to
- * refresh the dummy mapping (done to reserve the token) with
- * the mptcp_socket structure that wasn't allocated before.
- */
-void mptcp_token_update_accept(struct sock *sk, struct sock *conn)
-{
-	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
-	void __rcu **slot;
-
-	spin_lock_bh(&token_tree_lock);
-	slot = radix_tree_lookup_slot(&token_tree, subflow->token);
-	WARN_ON_ONCE(!slot);
-	if (slot) {
-		WARN_ON_ONCE(rcu_access_pointer(*slot) != &token_used);
-		radix_tree_replace_slot(&token_tree, slot, conn);
-	}
-	spin_unlock_bh(&token_tree_lock);
-}
-
-/**
  * mptcp_token_destroy_request - remove mptcp connection/token
  * @token - token of mptcp connection to remove
  *