[PATCH net-next 6/8] mptcp: avoid lock_fast usage in accept path
From: Mat Martineau <hidden>
Date: 2021-02-13 00:03:26
Also in:
mptcp
Subsystem:
networking [general], networking [mptcp], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Matthieu Baerts, Mat Martineau, Linus Torvalds
From: Florian Westphal <fw@strlen.de> Once event support is added this may need to allocate memory while msk lock is held with softirqs disabled. Not using lock_fast also allows to do the allocation with GFP_KERNEL. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Mat Martineau <redacted> --- net/mptcp/protocol.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 56240b87d464..fe6da1b77723 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c@@ -3260,9 +3260,8 @@ static int mptcp_stream_accept(struct socket *sock, struct socket *newsock, struct mptcp_sock *msk = mptcp_sk(newsock->sk); struct mptcp_subflow_context *subflow; struct sock *newsk = newsock->sk; - bool slowpath; - slowpath = lock_sock_fast(newsk); + lock_sock(newsk); /* PM/worker can now acquire the first subflow socket * lock without racing with listener queue cleanup,
@@ -3288,7 +3287,7 @@ static int mptcp_stream_accept(struct socket *sock, struct socket *newsock, if (!ssk->sk_socket) mptcp_sock_graft(ssk, newsock); } - unlock_sock_fast(newsk, slowpath); + release_sock(newsk); } if (inet_csk_listen_poll(ssock->sk))
--
2.30.1