From: Cong Wang <xiyou.wangc...@gmail.com> Date: Sun, 19 Aug 2018 12:22:12 -0700
> The only time we need to take tcfa_lock is when adding > a new metainfo to an existing ife->metalist. We don't need > to take tcfa_lock so early and so broadly in tcf_ife_init(). > > This means we can always take ife_mod_lock first, avoid the > reverse locking ordering warning as reported by Vlad. > > Reported-by: Vlad Buslov <vla...@mellanox.com> > Tested-by: Vlad Buslov <vla...@mellanox.com> > Cc: Vlad Buslov <vla...@mellanox.com> > Cc: Jamal Hadi Salim <j...@mojatatu.com> > Signed-off-by: Cong Wang <xiyou.wangc...@gmail.com> After this change we no longer call populate_metalist() in an atomic context via tcf_ife_init(), and populate_metalist passes 'exists' down to add_metainfo() as an 'atomic' indicator. It doesn't have this meaning if you aren't holding the tcfa_lock in the callers with BH disabled. Therefore, add_metainfo()'s 'atomic' indication is inaccurate in this call chain and will use GFP_ATOMIC unnecessarily. Probably the thing to just is just pass 'false' down to add_metainfo() in populate_metalist().
