From 89ab066d4229acd32e323f1569833302544a4186 Mon Sep 17 00:00:00 2001 From: Karsten Graul Date: Tue, 23 Oct 2018 13:40:39 +0200 Subject: Revert "net: simplify sock_poll_wait" This reverts commit dd979b4df817e9976f18fb6f9d134d6bc4a3c317. This broke tcp_poll for SMC fallback: An AF_SMC socket establishes an internal TCP socket for the initial handshake with the remote peer. Whenever the SMC connection can not be established this TCP socket is used as a fallback. All socket operations on the SMC socket are then forwarded to the TCP socket. In case of poll, the file->private_data pointer references the SMC socket because the TCP socket has no file assigned. This causes tcp_poll to wait on the wrong socket. Signed-off-by: Karsten Graul Signed-off-by: David S. Miller --- include/net/sock.h | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) (limited to 'include/net/sock.h') diff --git a/include/net/sock.h b/include/net/sock.h index 2440f8b407eb..f665d74ae509 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -2059,14 +2059,20 @@ static inline bool skwq_has_sleeper(struct socket_wq *wq) /** * sock_poll_wait - place memory barrier behind the poll_wait call. * @filp: file + * @sock: socket to wait on * @p: poll_table * * See the comments in the wq_has_sleeper function. + * + * Do not derive sock from filp->private_data here. An SMC socket establishes + * an internal TCP socket that is used in the fallback case. All socket + * operations on the SMC socket are then forwarded to the TCP socket. In case of + * poll, the filp->private_data pointer references the SMC socket because the + * TCP socket has no file assigned. */ -static inline void sock_poll_wait(struct file *filp, poll_table *p) +static inline void sock_poll_wait(struct file *filp, struct socket *sock, + poll_table *p) { - struct socket *sock = filp->private_data; - if (!poll_does_not_wait(p)) { poll_wait(filp, &sock->wq->wait, p); /* We need to be sure we are in sync with the -- cgit v1.2.3