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

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>
Signed-off-by: Jason Wang <redacted>
---
 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

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>
Signed-off-by: Jason Wang <redacted>
---
 drivers/net/tun.c |    9 +++++----
 1 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 2dddb1b..af9a096 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c

@@ -749,15 +749,16 @@ static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
 			  >= dev->tx_queue_len / tun->numqueues)
 		goto drop;
 
+	/* Orphan the skb - required as we might hang on to it
+	 * for indefinite time. */
+	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;
 	skb_orphan(skb);
 
 	nf_reset(skb);

-- 
1.7.1

Hello.

On 04-09-2013 8:33, Jason Wang wrote:

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>
Signed-off-by: Jason Wang <redacted>
---
  drivers/net/tun.c |    9 +++++----
  1 files changed, 5 insertions(+), 4 deletions(-)

    You could fix the comment style to the networking code default, while at: it:

/* bla
  * bla
  */

+	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;

WBR, Sergei

On 09/04/2013 09:27 PM, Sergei Shtylyov wrote:

Hello.

On 04-09-2013 8:33, Jason Wang wrote:

quoted

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.

quoted

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

quoted

Cc: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: Jason Wang <redacted>
---
  drivers/net/tun.c |    9 +++++----
  1 files changed, 5 insertions(+), 4 deletions(-)

quoted

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 2dddb1b..af9a096 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c

@@ -749,15 +749,16 @@ static netdev_tx_t tun_net_xmit(struct sk_buff

*skb, struct net_device *dev)
                >= dev->tx_queue_len / tun->numqueues)
          goto drop;

+    /* Orphan the skb - required as we might hang on to it
+     * for indefinite time. */

   You could fix the comment style to the networking code default,
while at: it:

/* bla
 * bla
 */

quoted

+    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;

WBR, Sergei

Sure will post V2.

On Wed, Sep 04, 2013 at 12:33:46PM +0800, Jason Wang wrote:

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>
Signed-off-by: Jason Wang <redacted>

Acked-by: Richard Cochran <richardcochran@gmail.com>

On Wed, Sep 04, 2013 at 12:33:45PM +0800, Jason Wang wrote:

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>
Signed-off-by: Jason Wang <redacted>

Acked-by: Richard Cochran <richardcochran@gmail.com>