On Thu, Jun 13, 2013 at 09:10:51AM -0700, Robert Love wrote:
> fcoe_xmit was coded such that it would skip the vlan net device/layer
> and instead set some vlan flags and transmit on the real net device.
> The real net device has code that would add the vlan tag for fcoe skbs.
> This avoids some extra processing for data frames and provides a small
> performance improvement.
>
> Since fcoe_xmit was not using the vlan net device, __vlan_put_tag
> within the real net device's xmit routine was ultimately being
> called to set the vlan tag.
>
> With the below change the behavior of __vlan_put_tag changed slightly,
> it now sets the skb->protocol = vlan_proto. vlan_proto was not a field
> being set by fcoe_xmit, so the skb->protocol is now not being set to
> ETH_P_8021Q, as it should be.
>
> This patch converts fcoe_xmit to use the vlan_put_tag routine which
> will tag the skb and fcoe will continue to transmit fcoe skbs on the
> real net device.
>
> For reference, the below change was the one that altered the
> __vlan_put_tag behavior.
>
> commit 86a9bad3ab6b6f858fd4443b48738cabbb6d094c
> Author: Patrick McHardy <[email protected]>
> Date: Fri Apr 19 02:04:30 2013 +0000
>
> net: vlan: add protocol argument to packet tagging functions
>
> Add a protocol argument to the VLAN packet tagging functions. In case
> of HW
> tagging, we need that protocol available in the ndo_start_xmit
> functions,
> so it is stored in a new field in the skb. The new field fits into a
> hole
> (on 64 bit) and doesn't increase the sks's size.
>
> Signed-off-by: Robert Love <[email protected]>
> ---
> drivers/scsi/fcoe/fcoe.c | 12 +++++-------
> 1 file changed, 5 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/scsi/fcoe/fcoe.c b/drivers/scsi/fcoe/fcoe.c
> index fc7bb1f..cb7ac9c 100644
> --- a/drivers/scsi/fcoe/fcoe.c
> +++ b/drivers/scsi/fcoe/fcoe.c
> @@ -1658,13 +1658,11 @@ static int fcoe_xmit(struct fc_lport *lport, struct
> fc_frame *fp)
> skb->protocol = htons(ETH_P_FCOE);
> skb->priority = fcoe->priority;
>
> - if (fcoe->netdev->priv_flags & IFF_802_1Q_VLAN &&
> - fcoe->realdev->features & NETIF_F_HW_VLAN_CTAG_TX) {
> - skb->vlan_tci = VLAN_TAG_PRESENT |
> - vlan_dev_vlan_id(fcoe->netdev);
> - skb->dev = fcoe->realdev;
> - } else
> - skb->dev = fcoe->netdev;
> + /* must set skb->dev before calling vlan_put_tag */
> + skb->dev = fcoe->realdev;
> + skb = vlan_put_tag(skb, htons(ETH_P_8021Q),
> vlan_dev_vlan_id(fcoe->netdev));
> + if (!skb)
> + return -ENOMEM;
>
> /* fill up mac and fcoe headers */
> eh = eth_hdr(skb);
>
> _______________________________________________
> fcoe-devel mailing list
> [email protected]
> http://lists.open-fcoe.org/mailman/listinfo/fcoe-devel
>
Acked-by: Neil Horman <[email protected]>
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