Patch "tcp: factor out __tcp_close() helper" has been added to the 4.19-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    tcp: factor out __tcp_close() helper

to the 4.19-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     tcp-factor-out-__tcp_close-helper.patch
and it can be found in the queue-4.19 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit d5d6d0a6afda5177ebaaff4c9f40537c4a3a6276
Author: Paolo Abeni <pabeni@xxxxxxxxxx>
Date:   Mon Nov 16 10:48:04 2020 +0100

    tcp: factor out __tcp_close() helper
    
    [ Upstream commit 77c3c95637526f1e4330cc9a4b2065f668c2c4fe ]
    
    unlocked version of protocol level close, will be used by
    MPTCP to allow decouple orphaning and subflow level close.
    
    Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
    Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
    Stable-dep-of: e14cadfd80d7 ("tcp: add annotations around sk->sk_shutdown accesses")
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/include/net/tcp.h b/include/net/tcp.h
index 9e37f3912ff19..81300a04b5808 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -389,6 +389,7 @@ void tcp_update_metrics(struct sock *sk);
 void tcp_init_metrics(struct sock *sk);
 void tcp_metrics_init(void);
 bool tcp_peer_is_proven(struct request_sock *req, struct dst_entry *dst);
+void __tcp_close(struct sock *sk, long timeout);
 void tcp_close(struct sock *sk, long timeout);
 void tcp_init_sock(struct sock *sk);
 void tcp_init_transfer(struct sock *sk, int bpf_op);
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 2fcf6e5a371dd..9200e7330b7d6 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2338,13 +2338,12 @@ bool tcp_check_oom(struct sock *sk, int shift)
 	return too_many_orphans || out_of_socket_memory;
 }
 
-void tcp_close(struct sock *sk, long timeout)
+void __tcp_close(struct sock *sk, long timeout)
 {
 	struct sk_buff *skb;
 	int data_was_unread = 0;
 	int state;
 
-	lock_sock(sk);
 	sk->sk_shutdown = SHUTDOWN_MASK;
 
 	if (sk->sk_state == TCP_LISTEN) {
@@ -2505,6 +2504,12 @@ void tcp_close(struct sock *sk, long timeout)
 out:
 	bh_unlock_sock(sk);
 	local_bh_enable();
+}
+
+void tcp_close(struct sock *sk, long timeout)
+{
+	lock_sock(sk);
+	__tcp_close(sk, timeout);
 	release_sock(sk);
 	sock_put(sk);
 }