On Mon, Apr 22, 2019 at 6:35 PM Eric Dumazet <eduma...@google.com> wrote:
>
> Instead of using atomic_inc(), prefer fib6_info_hold()
> so that upcoming refcount_t conversion is simpler.
>
> Only fib6_info_alloc() is using atomic_set() since we
> just allocated a new object.
>
> Signed-off-by: Eric Dumazet <eduma...@google.com>
> Cc: Wei Wang <wei...@google.com>
> ---
Acked-by: Wei Wang <wei...@google.com>
> net/ipv6/ip6_fib.c | 16 ++++++++--------
> 1 file changed, 8 insertions(+), 8 deletions(-)
>
> diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
> index
> 55193859152969794dab3df02637217a7f21016f..a5e83593e0e45c2762eca85d04757f9d8e118e0f
> 100644
> --- a/net/ipv6/ip6_fib.c
> +++ b/net/ipv6/ip6_fib.c
> @@ -162,7 +162,7 @@ struct fib6_info *fib6_info_alloc(gfp_t gfp_flags)
> }
>
> INIT_LIST_HEAD(&f6i->fib6_siblings);
> - atomic_inc(&f6i->fib6_ref);
> + atomic_set(&f6i->fib6_ref, 1);
>
> return f6i;
> }
> @@ -846,8 +846,8 @@ static struct fib6_node *fib6_add_1(struct net *net,
>
> RCU_INIT_POINTER(in->parent, pn);
> in->leaf = fn->leaf;
> - atomic_inc(&rcu_dereference_protected(in->leaf,
> - lockdep_is_held(&table->tb6_lock))->fib6_ref);
> + fib6_info_hold(rcu_dereference_protected(in->leaf,
> + lockdep_is_held(&table->tb6_lock)));
>
> /* update parent pointer */
> if (dir)
> @@ -942,7 +942,7 @@ static void fib6_purge_rt(struct fib6_info *rt, struct
> fib6_node *fn,
> struct fib6_info *new_leaf;
> if (!(fn->fn_flags & RTN_RTINFO) && leaf == rt) {
> new_leaf = fib6_find_prefix(net, table, fn);
> - atomic_inc(&new_leaf->fib6_ref);
> + fib6_info_hold(new_leaf);
>
> rcu_assign_pointer(fn->leaf, new_leaf);
> fib6_info_release(rt);
> @@ -1108,7 +1108,7 @@ static int fib6_add_rt2node(struct fib6_node *fn,
> struct fib6_info *rt,
> return err;
>
> rcu_assign_pointer(rt->fib6_next, iter);
> - atomic_inc(&rt->fib6_ref);
> + fib6_info_hold(rt);
> rcu_assign_pointer(rt->fib6_node, fn);
> rcu_assign_pointer(*ins, rt);
> if (!info->skip_notify)
> @@ -1136,7 +1136,7 @@ static int fib6_add_rt2node(struct fib6_node *fn,
> struct fib6_info *rt,
> if (err)
> return err;
>
> - atomic_inc(&rt->fib6_ref);
> + fib6_info_hold(rt);
> rcu_assign_pointer(rt->fib6_node, fn);
> rt->fib6_next = iter->fib6_next;
> rcu_assign_pointer(*ins, rt);
> @@ -1278,7 +1278,7 @@ int fib6_add(struct fib6_node *root, struct fib6_info
> *rt,
> if (!sfn)
> goto failure;
>
> -
> atomic_inc(&info->nl_net->ipv6.fib6_null_entry->fib6_ref);
> + fib6_info_hold(info->nl_net->ipv6.fib6_null_entry);
> rcu_assign_pointer(sfn->leaf,
>
> info->nl_net->ipv6.fib6_null_entry);
> sfn->fn_flags = RTN_ROOT;
> @@ -1321,7 +1321,7 @@ int fib6_add(struct fib6_node *root, struct fib6_info
> *rt,
> rcu_assign_pointer(fn->leaf,
>
> info->nl_net->ipv6.fib6_null_entry);
> } else {
> - atomic_inc(&rt->fib6_ref);
> + fib6_info_hold(rt);
> rcu_assign_pointer(fn->leaf, rt);
> }
> }
> --
> 2.21.0.593.g511ec345e18-goog
>
