[PATCH V2 net-next 1/2] tuntap: purge socket error queue on detach

[PATCH V2 net-next 1/2] tuntap: purge socket error queue on detach

[Jason Wang]

Commit eda297729171fe16bf34fe5b0419dfb69060f623
(tun: Support software transmit time stamping) will queue skbs into error queue
when tx stamping is enabled. But it forgets to purge the error queue during
detach. This patch fixes this.

Cc: Richard Cochran <richardcochran@gmail.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 drivers/net/tun.c |   12 +++++++++---
 1 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 60a1e93..2dddb1b 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -409,6 +409,12 @@ static struct tun_struct *tun_enable_queue(struct tun_file *tfile)
 	return tun;
 }
 
+static void tun_queue_purge(struct tun_file *tfile)
+{
+	skb_queue_purge(&tfile->sk.sk_receive_queue);
+	skb_queue_purge(&tfile->sk.sk_error_queue);
+}
+
 static void __tun_detach(struct tun_file *tfile, bool clean)
 {
 	struct tun_file *ntfile;
@@ -435,7 +441,7 @@ static void __tun_detach(struct tun_file *tfile, bool clean)
 		synchronize_net();
 		tun_flow_delete_by_queue(tun, tun->numqueues + 1);
 		/* Drop read queue */
-		skb_queue_purge(&tfile->sk.sk_receive_queue);
+		tun_queue_purge(tfile);
 		tun_set_real_num_queues(tun);
 	} else if (tfile->detached && clean) {
 		tun = tun_enable_queue(tfile);
@@ -487,12 +493,12 @@ static void tun_detach_all(struct net_device *dev)
 	for (i = 0; i < n; i++) {
 		tfile = rtnl_dereference(tun->tfiles[i]);
 		/* Drop read queue */
-		skb_queue_purge(&tfile->sk.sk_receive_queue);
+		tun_queue_purge(tfile);
 		sock_put(&tfile->sk);
 	}
 	list_for_each_entry_safe(tfile, tmp, &tun->disabled, next) {
 		tun_enable_queue(tfile);
-		skb_queue_purge(&tfile->sk.sk_receive_queue);
+		tun_queue_purge(tfile);
 		sock_put(&tfile->sk);
 	}
 	BUG_ON(tun->numdisabled != 0);
-- 
1.7.1

[PATCH V2 net-next 2/2] tuntap: orphan frags before trying to set tx timestamp

[Jason Wang]

sock_tx_timestamp() will clear all zerocopy flags of skb which may lead the
frags never to be orphaned. This will break guest to guest traffic when zerocopy
is enabled. Fix this by orphaning the frags before trying to set tx time stamp.

The issue were introduced by commit eda297729171fe16bf34fe5b0419dfb69060f623
(tun: Support software transmit time stamping).

Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
Changes from v1:
- correct the comment location and style
---
 drivers/net/tun.c |    8 +++++---
 1 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 2dddb1b..a639de8 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -749,15 +749,17 @@ static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
 			  >= dev->tx_queue_len / tun->numqueues)
 		goto drop;
 
+	if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC)))
+		goto drop;
+
 	if (skb->sk) {
 		sock_tx_timestamp(skb->sk, &skb_shinfo(skb)->tx_flags);
 		sw_tx_timestamp(skb);
 	}
 
 	/* Orphan the skb - required as we might hang on to it
-	 * for indefinite time. */
-	if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC)))
-		goto drop;
+	 * for indefinite time.
+	 */
 	skb_orphan(skb);
 
 	nf_reset(skb);
-- 
1.7.1

Re: [PATCH V2 net-next 1/2] tuntap: purge socket error queue on detach

[David Miller]

From: Jason Wang <jasowang@redhat.com>
Date: Thu,  5 Sep 2013 17:53:59 +0800

> Commit eda297729171fe16bf34fe5b0419dfb69060f623
> (tun: Support software transmit time stamping) will queue skbs into error queue
> when tx stamping is enabled. But it forgets to purge the error queue during
> detach. This patch fixes this.
> 
> Cc: Richard Cochran <richardcochran@gmail.com>
> Acked-by: Richard Cochran <richardcochran@gmail.com>
> Signed-off-by: Jason Wang <jasowang@redhat.com>

Applied.

Re: [PATCH V2 net-next 2/2] tuntap: orphan frags before trying to set tx timestamp

[David Miller]

From: Jason Wang <jasowang@redhat.com>
Date: Thu,  5 Sep 2013 17:54:00 +0800

> sock_tx_timestamp() will clear all zerocopy flags of skb which may lead the
> frags never to be orphaned. This will break guest to guest traffic when zerocopy
> is enabled. Fix this by orphaning the frags before trying to set tx time stamp.
> 
> The issue were introduced by commit eda297729171fe16bf34fe5b0419dfb69060f623
> (tun: Support software transmit time stamping).
> 
> Cc: Richard Cochran <richardcochran@gmail.com>
> Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
> Acked-by: Richard Cochran <richardcochran@gmail.com>
> Signed-off-by: Jason Wang <jasowang@redhat.com>

Applied.

I also queued both of these patches to -stable.

Thanks.