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From: Jason Wang <jasowang@redhat.com>
To: davem@davemloft.net, mst@redhat.com, netdev@vger.kernel.org,
	linux-kernel@vger.kernel.org
Cc: Jason Wang <jasowang@redhat.com>
Subject: [PATCH V2 3/3] tuntap: don't add to waitqueue when POLLERR
Date: Sat,  5 Jan 2013 17:34:06 +0800	[thread overview]
Message-ID: <1357378446-19656-4-git-send-email-jasowang@redhat.com> (raw)
In-Reply-To: <1357378446-19656-1-git-send-email-jasowang@redhat.com>

Currently, tun_chr_poll() returns POLLERR after waitqueue adding during device
unregistration. This would confuse some of its user such as vhost which assume
when POLLERR is returned, it wasn't added to the waitqueue. Fix this by
returning POLLERR before adding to waitqueue.

Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 drivers/net/tun.c |    5 +----
 1 files changed, 1 insertions(+), 4 deletions(-)

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index fbd106e..f9c0049 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -886,7 +886,7 @@ static unsigned int tun_chr_poll(struct file *file, poll_table *wait)
 	struct sock *sk;
 	unsigned int mask = 0;
 
-	if (!tun)
+	if (!tun || tun->dev->reg_state != NETREG_REGISTERED)
 		return POLLERR;
 
 	sk = tfile->socket.sk;
@@ -903,9 +903,6 @@ static unsigned int tun_chr_poll(struct file *file, poll_table *wait)
 	     sock_writeable(sk)))
 		mask |= POLLOUT | POLLWRNORM;
 
-	if (tun->dev->reg_state != NETREG_REGISTERED)
-		mask = POLLERR;
-
 	tun_put(tun);
 	return mask;
 }
-- 
1.7.1


  parent reply	other threads:[~2013-01-05  9:42 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-01-05  9:34 [PATCH V2 0/3] handle polling errors in vhost/vhost_net Jason Wang
2013-01-05  9:34 ` [PATCH V2 1/3] vhost_net: correct error handling in vhost_net_set_backend() Jason Wang
2013-01-05  9:34 ` [PATCH V2 2/3] vhost: handle polling errors Jason Wang
2013-01-05  9:34 ` Jason Wang [this message]
2013-01-05 19:37   ` [PATCH V2 3/3] tuntap: don't add to waitqueue when POLLERR Eric Dumazet
2013-01-06  4:43     ` Jason Wang

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