| Message ID | 1399540537-19262-1-git-send-email-pch@ordbogen.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
From: Peter Christensen <pch@ordbogen.com> Date: Thu, 8 May 2014 11:15:37 +0200 > Clearing the IFF_ALLMULTI flag on a down interface could cause an allmulti > overflow on the underlying interface. > > Attempting the set IFF_ALLMULTI on the underlying interface would cause an > error and the log message: > > "allmulti touches root, set allmulti failed." > > Signed-off-by: Peter Christensen <pch@ordbogen.com> Hmmm, but won't we lose this event once the interface is brought back up? -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, 09 May 2014 16:02:25 -0400 (EDT) David Miller <davem@davemloft.net> wrote: > From: Peter Christensen <pch@ordbogen.com> > Date: Thu, 8 May 2014 11:15:37 +0200 > > > Clearing the IFF_ALLMULTI flag on a down interface could cause an > > allmulti overflow on the underlying interface. > > > > Attempting the set IFF_ALLMULTI on the underlying interface would > > cause an error and the log message: > > > > "allmulti touches root, set allmulti failed." > > > > Signed-off-by: Peter Christensen <pch@ordbogen.com> > > Hmmm, but won't we lose this event once the interface is brought > back up? No, macvlan_open and macvlan_stop already takes care of that (which is part of the reason the allmulti counter overflowed). Either macvlan_open and macvlan_close shouldn't touch the flag on the underlying interface, or macvlan_change_rx_flags shouldn't touch the underlying interface if the MACVLAN interface is down. I though that it was probably better to make MACVLAN as non-intrusive to the underlying interface when the MACVLAN interface is down, so I opted for this solution. Apparently the 802.1Q VLAN driver behaves exactly like that, and back in 2011 it got a patch similar to this one (commit deede2fabe24e00bd7e246eb81cd5767dc6fcfc7). -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From: Peter Christensen <pch@ordbogen.com> Date: Mon, 12 May 2014 09:59:53 +0200 > On Fri, 09 May 2014 16:02:25 -0400 (EDT) > David Miller <davem@davemloft.net> wrote: > >> From: Peter Christensen <pch@ordbogen.com> >> Date: Thu, 8 May 2014 11:15:37 +0200 >> >> > Clearing the IFF_ALLMULTI flag on a down interface could cause an >> > allmulti overflow on the underlying interface. >> > >> > Attempting the set IFF_ALLMULTI on the underlying interface would >> > cause an error and the log message: >> > >> > "allmulti touches root, set allmulti failed." >> > >> > Signed-off-by: Peter Christensen <pch@ordbogen.com> >> >> Hmmm, but won't we lose this event once the interface is brought >> back up? > > No, macvlan_open and macvlan_stop already takes care of that (which is > part of the reason the allmulti counter overflowed). Either > macvlan_open and macvlan_close shouldn't touch the flag on the > underlying interface, or > macvlan_change_rx_flags shouldn't touch the underlying interface if the > MACVLAN interface is down. > > I though that it was probably better to make MACVLAN as non-intrusive > to the underlying interface when the MACVLAN interface is down, so I > opted for this solution. > > Apparently the 802.1Q VLAN driver behaves > exactly like that, and back in 2011 it got a patch similar to this one > (commit deede2fabe24e00bd7e246eb81cd5767dc6fcfc7). Thanks for the detailed explanation, applied and queued up for -stable, thanks! -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c index b0e2865..c5fb9cf 100644 --- a/drivers/net/macvlan.c +++ b/drivers/net/macvlan.c @@ -458,8 +458,10 @@ static void macvlan_change_rx_flags(struct net_device *dev, int change) struct macvlan_dev *vlan = netdev_priv(dev); struct net_device *lowerdev = vlan->lowerdev; - if (change & IFF_ALLMULTI) - dev_set_allmulti(lowerdev, dev->flags & IFF_ALLMULTI ? 1 : -1); + if (dev->flags & IFF_UP) { + if (change & IFF_ALLMULTI) + dev_set_allmulti(lowerdev, dev->flags & IFF_ALLMULTI ? 1 : -1); + } } static void macvlan_set_mac_lists(struct net_device *dev)
Clearing the IFF_ALLMULTI flag on a down interface could cause an allmulti overflow on the underlying interface. Attempting the set IFF_ALLMULTI on the underlying interface would cause an error and the log message: "allmulti touches root, set allmulti failed." Signed-off-by: Peter Christensen <pch@ordbogen.com> --- drivers/net/macvlan.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)