Messages in this thread | | | Date | Wed, 25 Oct 2023 15:40:23 -0700 | From | Jakub Kicinski <> | Subject | Re: [PATCH net-next v8 4/7] net: macsec: introduce mdo_insert_tx_tag |
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On Mon, 23 Oct 2023 12:43:24 +0300 Radu Pirea (NXP OSS) wrote: > + if (unlikely(skb_headroom(skb) < ops->needed_headroom || > + skb_tailroom(skb) < ops->needed_tailroom)) {
This sort of "if head / tail room is to small, realloc" helper would be more widely applicable, we should factor it out.
> + struct sk_buff *nskb = skb_copy_expand(skb,
And this should perhaps be pskb_expand_head().
> + ops->needed_headroom, > + ops->needed_tailroom, > + GFP_ATOMIC); > + if (likely(nskb)) { > + consume_skb(skb); > + skb = nskb; > + } else { > + err = -ENOMEM; > + goto cleanup; > + } > + } else { > + skb = skb_unshare(skb, GFP_ATOMIC);
You don't need to unshare if tailroom is 0, you just need to call skb_cow_head().
I think we have this sort of code in DSA already, IIRC Vladimir wrote it. dsa_realloc_skb() ? Can we factor out / reuse that?
> + if (!skb) > + return ERR_PTR(-ENOMEM); > + } > + > + err = ops->mdo_insert_tx_tag(phydev, skb); > + if (unlikely(err)) > + goto cleanup; > + > + if (unlikely(skb->len - ETH_HLEN > macsec_priv(dev)->real_dev->mtu)) {
You can check that first, if the packet is going to be dropped no point doing the expansions.
> + err = -EINVAL; > + goto cleanup; > + }
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