lkml.org 
[lkml]   [2018]   [May]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH net] tuntap: raise EPOLLOUT on device up
Date
We return -EIO on device down but can not raise EPOLLOUT after it was
up. This may confuse user like vhost which expects tuntap to raise
EPOLLOUT to re-enable its TX routine after tuntap is down. This could
be easily reproduced by transmitting packets from VM while down and up
the tap device. Fixing this by set SOCKWQ_ASYNC_NOSPACE on -EIO.

Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Cc: Eric Dumazet <edumazet@google.com>
Fixes: 1bd4978a88ac2 ("tun: honor IFF_UP in tun_get_user()")
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
drivers/net/tun.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index d45ac37..1b29761 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1734,8 +1734,10 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
int skb_xdp = 1;
bool frags = tun_napi_frags_enabled(tun);

- if (!(tun->dev->flags & IFF_UP))
+ if (!(tun->dev->flags & IFF_UP)) {
+ set_bit(SOCKWQ_ASYNC_NOSPACE, &tfile->socket.flags);
return -EIO;
+ }

if (!(tun->flags & IFF_NO_PI)) {
if (len < sizeof(pi))
--
2.7.4
\
 
 \ /
  Last update: 2018-05-18 15:01    [W:0.114 / U:1.372 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site