netdev - [PATCH 3/6] net: don't detour through struct to find the poll head

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Message-Id: <20180628142059.10017-4-hch@lst.de>
Date:   Thu, 28 Jun 2018 16:20:56 +0200
From:   Christoph Hellwig <hch@....de>
To:     Alexander Viro <viro@...iv.linux.org.uk>
Cc:     Linus Torvalds <torvalds@...ux-foundation.org>,
        linux-fsdevel@...r.kernel.org, netdev@...r.kernel.org, lkp@...org
Subject: [PATCH 3/6] net: don't detour through struct to find the poll head

As far as I can tell sock->sk->sk_wq->wait will always point to
sock->wq->wait.  That means we can do the shorter dereference and
not worry about any RCU protection.

Signed-off-by: Christoph Hellwig <hch@....de>
---
 net/socket.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/socket.c b/net/socket.c
index fe6620607b07..7cf037d21805 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -1136,7 +1136,7 @@ static struct wait_queue_head *sock_get_poll_head(struct file *file,
 	if (!sock->ops->poll_mask)
 		return NULL;
 	sock_poll_busy_loop(sock, events);
-	return sk_sleep(sock->sk);
+	return &sock->wq->wait;
 }
 
 static __poll_t sock_poll_mask(struct file *file, __poll_t events)
-- 
2.17.1