diff mbox series

[net-next,01/13] mptcp: clean-up the rtx path

Message ID 20210326182642.136419-1-mathew.j.martineau@linux.intel.com (mailing list archive)
State Accepted
Commit 2d6f5a2b5720cd3fdbaa21d8f5a6a192257b2a3c
Delegated to: Netdev Maintainers
Headers show
Series MPTCP: Cleanup and address advertisement fixes | expand

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netdev/build_32bit success Errors and warnings before: 2 this patch: 2
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netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 89 lines checked
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Commit Message

Mat Martineau March 26, 2021, 6:26 p.m. UTC 
From: Paolo Abeni <pabeni@redhat.com>

After the previous patch we can easily avoid invoking
the workqueue to perform the retransmission, if the
msk socket lock is held at rtx timer expiration.

This also simplifies the relevant code.

Co-developed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
---
 net/mptcp/protocol.c | 42 +++++++++++-------------------------------
 net/mptcp/protocol.h |  1 +
 2 files changed, 12 insertions(+), 31 deletions(-)
diff mbox series

Patch

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 1590b9d4cde2..171b77537dcb 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -2047,28 +2047,21 @@  static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
 	return copied;
 }
 
-static void mptcp_retransmit_handler(struct sock *sk)
-{
-	struct mptcp_sock *msk = mptcp_sk(sk);
-
-	set_bit(MPTCP_WORK_RTX, &msk->flags);
-	mptcp_schedule_work(sk);
-}
-
 static void mptcp_retransmit_timer(struct timer_list *t)
 {
 	struct inet_connection_sock *icsk = from_timer(icsk, t,
 						       icsk_retransmit_timer);
 	struct sock *sk = &icsk->icsk_inet.sk;
+	struct mptcp_sock *msk = mptcp_sk(sk);
 
 	bh_lock_sock(sk);
 	if (!sock_owned_by_user(sk)) {
-		mptcp_retransmit_handler(sk);
+		/* we need a process context to retransmit */
+		if (!test_and_set_bit(MPTCP_WORK_RTX, &msk->flags))
+			mptcp_schedule_work(sk);
 	} else {
 		/* delegate our work to tcp_release_cb() */
-		if (!test_and_set_bit(TCP_WRITE_TIMER_DEFERRED,
-				      &sk->sk_tsq_flags))
-			sock_hold(sk);
+		set_bit(MPTCP_RETRANSMIT, &msk->flags);
 	}
 	bh_unlock_sock(sk);
 	sock_put(sk);
@@ -2958,17 +2951,16 @@  void __mptcp_check_push(struct sock *sk, struct sock *ssk)
 	}
 }
 
-#define MPTCP_DEFERRED_ALL (TCPF_WRITE_TIMER_DEFERRED)
-
 /* processes deferred events and flush wmem */
 static void mptcp_release_cb(struct sock *sk)
 {
-	unsigned long flags, nflags;
-
 	for (;;) {
-		flags = 0;
+		unsigned long flags = 0;
+
 		if (test_and_clear_bit(MPTCP_PUSH_PENDING, &mptcp_sk(sk)->flags))
 			flags |= BIT(MPTCP_PUSH_PENDING);
+		if (test_and_clear_bit(MPTCP_RETRANSMIT, &mptcp_sk(sk)->flags))
+			flags |= BIT(MPTCP_RETRANSMIT);
 		if (!flags)
 			break;
 
@@ -2983,6 +2975,8 @@  static void mptcp_release_cb(struct sock *sk)
 		spin_unlock_bh(&sk->sk_lock.slock);
 		if (flags & BIT(MPTCP_PUSH_PENDING))
 			__mptcp_push_pending(sk, 0);
+		if (flags & BIT(MPTCP_RETRANSMIT))
+			__mptcp_retrans(sk);
 
 		cond_resched();
 		spin_lock_bh(&sk->sk_lock.slock);
@@ -2998,20 +2992,6 @@  static void mptcp_release_cb(struct sock *sk)
 	 */
 	__mptcp_update_wmem(sk);
 	__mptcp_update_rmem(sk);
-
-	do {
-		flags = sk->sk_tsq_flags;
-		if (!(flags & MPTCP_DEFERRED_ALL))
-			return;
-		nflags = flags & ~MPTCP_DEFERRED_ALL;
-	} while (cmpxchg(&sk->sk_tsq_flags, flags, nflags) != flags);
-
-	sock_release_ownership(sk);
-
-	if (flags & TCPF_WRITE_TIMER_DEFERRED) {
-		mptcp_retransmit_handler(sk);
-		__sock_put(sk);
-	}
 }
 
 void mptcp_subflow_process_delegated(struct sock *ssk)
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index 1111a99b024f..0116308f5f69 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -104,6 +104,7 @@ 
 #define MPTCP_PUSH_PENDING	6
 #define MPTCP_CLEAN_UNA		7
 #define MPTCP_ERROR_REPORT	8
+#define MPTCP_RETRANSMIT	9
 
 static inline bool before64(__u64 seq1, __u64 seq2)
 {