[PATCH 5.18 297/879] mptcp: optimize release_cb for the common case

Greg Kroah-Hartman
2022-06-07T22:27:23Z

From: Paolo Abeni <pabeni@redhat.com>

[ Upstream commit 65a569b03ca832ebc93ce45a7466137e2bb62254 ]

The mptcp release callback checks several flags in atomic
context, but only MPTCP_CLEAN_UNA can be up frequently.

Reorganize the code to avoid multiple conditionals in the
most common scenarios.

Additional clarify a related comment.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/mptcp/protocol.c | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 0cbea3b6d0a4..2a9335ce5df1 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -3092,15 +3092,17 @@ static void mptcp_release_cb(struct sock *sk)
spin_lock_bh(&sk->sk_lock.slock);
}

- /* be sure to set the current sk state before tacking actions
- * depending on sk_state
- */
- if (__test_and_clear_bit(MPTCP_CONNECTED, &msk->cb_flags))
- __mptcp_set_connected(sk);
if (__test_and_clear_bit(MPTCP_CLEAN_UNA, &msk->cb_flags))
__mptcp_clean_una_wakeup(sk);
- if (__test_and_clear_bit(MPTCP_ERROR_REPORT, &msk->cb_flags))
- __mptcp_error_report(sk);
+ if (unlikely(&msk->cb_flags)) {
+ /* be sure to set the current sk state before tacking actions
+ * depending on sk_state, that is processing MPTCP_ERROR_REPORT
+ */
+ if (__test_and_clear_bit(MPTCP_CONNECTED, &msk->cb_flags))
+ __mptcp_set_connected(sk);
+ if (__test_and_clear_bit(MPTCP_ERROR_REPORT, &msk->cb_flags))
+ __mptcp_error_report(sk);
+ }

__mptcp_update_rmem(sk);
}
--
2.35.1