Re: [PATCH] net: linearizing skb when downgrade gso_size

No need for ternary statement.

Instead of the complex test in skb_is_nonsg, can we just assume that
alignment will be off if having frag_list and changing gso_size.

The same will apply to bpf_skb_net_shrink too.

increase gso_size may be no problem and we can use BPF_F_ADJ_ROOM_FIXED_GSO
to avoid update gso_size when shrink.

Not sure that it is okay to linearize inside a BPF helper function.
Hopefully bpf experts can chime in on that.

Thanks

Fred Li