+Andrew, Vivien, On Mon, Mar 15, 2021 at 02:53:26PM +0100, gregkh@xxxxxxxxxxxxxxxxxxx wrote: > From: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> > > From: Vladimir Oltean <vladimir.oltean@xxxxxxx> > > [ Upstream commit a3b0b6479700a5b0af2c631cb2ec0fb7a0d978f2 ] > > At the moment, taggers are left with the task of ensuring that the skb > headers are writable (which they aren't, if the frames were cloned for > TX timestamping, for flooding by the bridge, etc), and that there is > enough space in the skb data area for the DSA tag to be pushed. > > Moreover, the life of tail taggers is even harder, because they need to > ensure that short frames have enough padding, a problem that normal > taggers don't have. > > The principle of the DSA framework is that everything except for the > most intimate hardware specifics (like in this case, the actual packing > of the DSA tag bits) should be done inside the core, to avoid having > code paths that are very rarely tested. > > So provide a TX reallocation procedure that should cover the known needs > of DSA today. > > Note that this patch also gives the network stack a good hint about the > headroom/tailroom it's going to need. Up till now it wasn't doing that. > So the reallocation procedure should really be there only for the > exceptional cases, and for cloned packets which need to be unshared. > > Signed-off-by: Vladimir Oltean <vladimir.oltean@xxxxxxx> > Tested-by: Christian Eggers <ceggers@xxxxxxx> # For tail taggers only > Tested-by: Kurt Kanzenbach <kurt@xxxxxxxxxxxxx> > Reviewed-by: Florian Fainelli <f.fainelli@xxxxxxxxx> > Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> > Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> > --- For context, Sasha explains here: https://www.spinics.net/lists/stable-commits/msg190151.html (the conversation is somewhat truncated, unfortunately, because stable-commits@xxxxxxxxxxxxxxx ate my replies) that 13 patches were backported to get the unrelated commit 9200f515c41f ("net: dsa: tag_mtk: fix 802.1ad VLAN egress") to apply cleanly with git-am. I am not strictly against this, even though I would have liked to know that the maintainers were explicitly informed about it. Greg, could you make your stable backporting emails include the output of ./get_maintainer.pl into the list of recipients? Thanks.
