On Fri, Aug 14, 2020 at 9:20 AM linmiaohe <linmia...@huawei.com> wrote: > > Willem de Bruijn <willemdebruijn.ker...@gmail.com> wrote: > >On Thu, Aug 13, 2020 at 2:16 PM Miaohe Lin <linmia...@huawei.com> wrote: > >> > >> If the skb is zcopied, we should increase the skb_uarg refcount before > >> we involve skb_release_data(). See pskb_expand_head() as a reference. > > > >Did you manage to observe a bug through this datapath in practice? > > > >pskb_carve_inside_header is called > > from pskb_carve > > from pskb_extract > > from rds_tcp_data_recv > > > >That receive path should not see any packets with zerocopy state associated. > > > > This works fine yet as its caller is limited. But we should take care of the > skb_uarg refcount for future use.
If a new application of this interface is proposed, the author will have to make sure that it is exercised correctly. > On the other hand, because this codepath should not see any packets with > zerocopy state associated, then we > should not call skb_orphan_frags here. I'm also not convinced that the skb_orphan_frags here are needed, given the only path is from tcp_read_sock.
