[net-next] tun/macvtap: use consume_skb() instead of kfree_skb() in tun/macvtap_do_read()
diff mbox series

Message ID 1416982084-12212-1-git-send-email-jasowang@redhat.com
State New, archived
Headers show
Series
  • [net-next] tun/macvtap: use consume_skb() instead of kfree_skb() in tun/macvtap_do_read()
Related show

Commit Message

Jason Wang Nov. 26, 2014, 6:08 a.m. UTC
To be more friendly with drop monitor, we should use comsume_skb() instead
of kfree_skb() in tun/macvtap_do_read(). Otherwise, the packets will be
marked as dropped.

Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 drivers/net/macvtap.c | 2 +-
 drivers/net/tun.c     | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

Comments

Eric Dumazet Nov. 26, 2014, 6:26 a.m. UTC | #1
On Wed, 2014-11-26 at 14:08 +0800, Jason Wang wrote:
> To be more friendly with drop monitor, we should use comsume_skb() instead
> of kfree_skb() in tun/macvtap_do_read(). Otherwise, the packets will be
> marked as dropped.
> 
> Signed-off-by: Jason Wang <jasowang@redhat.com>
> ---
>  drivers/net/macvtap.c | 2 +-
>  drivers/net/tun.c     | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
> index 42a80d3..74d1b23 100644
> --- a/drivers/net/macvtap.c
> +++ b/drivers/net/macvtap.c
> @@ -862,7 +862,7 @@ static ssize_t macvtap_do_read(struct macvtap_queue *q,
>  		}
>  		iov_iter_init(&iter, READ, iv, segs, len);
>  		ret = macvtap_put_user(q, skb, &iter);
> -		kfree_skb(skb);
> +		consume_skb(skb);
>  		break;
>  	}
>  
> diff --git a/drivers/net/tun.c b/drivers/net/tun.c
> index ac53a73..d7edeaf 100644
> --- a/drivers/net/tun.c
> +++ b/drivers/net/tun.c
> @@ -1363,7 +1363,7 @@ static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile,
>  
>  	iov_iter_init(&iter, READ, iv, segs, len);
>  	ret = tun_put_user(tun, tfile, skb, &iter);
> -	kfree_skb(skb);
> +	consume_skb(skb);
>  
>  	return ret;
>  }


These patches keep going on, but they are wrong.

If you care about drop monitor, then you want to not hide drops but
precisely report them.

Surely tun_put_user() can return an error, and then packet _is_ dropped.



--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/
Jason Wang Nov. 26, 2014, 6:41 a.m. UTC | #2
On 11/26/2014 02:26 PM, Eric Dumazet wrote:
> On Wed, 2014-11-26 at 14:08 +0800, Jason Wang wrote:
>> To be more friendly with drop monitor, we should use comsume_skb() instead
>> of kfree_skb() in tun/macvtap_do_read(). Otherwise, the packets will be
>> marked as dropped.
>>
>> Signed-off-by: Jason Wang <jasowang@redhat.com>
>> ---
>>  drivers/net/macvtap.c | 2 +-
>>  drivers/net/tun.c     | 2 +-
>>  2 files changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
>> index 42a80d3..74d1b23 100644
>> --- a/drivers/net/macvtap.c
>> +++ b/drivers/net/macvtap.c
>> @@ -862,7 +862,7 @@ static ssize_t macvtap_do_read(struct macvtap_queue *q,
>>  		}
>>  		iov_iter_init(&iter, READ, iv, segs, len);
>>  		ret = macvtap_put_user(q, skb, &iter);
>> -		kfree_skb(skb);
>> +		consume_skb(skb);
>>  		break;
>>  	}
>>  
>> diff --git a/drivers/net/tun.c b/drivers/net/tun.c
>> index ac53a73..d7edeaf 100644
>> --- a/drivers/net/tun.c
>> +++ b/drivers/net/tun.c
>> @@ -1363,7 +1363,7 @@ static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile,
>>  
>>  	iov_iter_init(&iter, READ, iv, segs, len);
>>  	ret = tun_put_user(tun, tfile, skb, &iter);
>> -	kfree_skb(skb);
>> +	consume_skb(skb);
>>  
>>  	return ret;
>>  }
>
> These patches keep going on, but they are wrong.
>
> If you care about drop monitor, then you want to not hide drops but
> precisely report them.
>
> Surely tun_put_user() can return an error, and then packet _is_ dropped.

True, I miss this. Will post V2. Thanks

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Patch
diff mbox series

diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
index 42a80d3..74d1b23 100644
--- a/drivers/net/macvtap.c
+++ b/drivers/net/macvtap.c
@@ -862,7 +862,7 @@  static ssize_t macvtap_do_read(struct macvtap_queue *q,
 		}
 		iov_iter_init(&iter, READ, iv, segs, len);
 		ret = macvtap_put_user(q, skb, &iter);
-		kfree_skb(skb);
+		consume_skb(skb);
 		break;
 	}
 
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index ac53a73..d7edeaf 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1363,7 +1363,7 @@  static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile,
 
 	iov_iter_init(&iter, READ, iv, segs, len);
 	ret = tun_put_user(tun, tfile, skb, &iter);
-	kfree_skb(skb);
+	consume_skb(skb);
 
 	return ret;
 }