From aa539cb38f4f1365ad52fed6a857b25f8b4dc06c Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 14 May 2013 13:52:31 -0700 Subject: blkcg: implement blkg_for_each_descendant_post() This will be used by blk-throttle hierarchy support. Signed-off-by: Tejun Heo Acked-by: Vivek Goyal --- block/blk-cgroup.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h index 11f5b92d9a47..e15f731d2cdd 100644 --- a/block/blk-cgroup.h +++ b/block/blk-cgroup.h @@ -302,6 +302,20 @@ struct blkcg_gq *__blkg_lookup(struct blkcg *blkcg, struct request_queue *q, if (((d_blkg) = __blkg_lookup(cgroup_to_blkcg(pos_cgrp), \ (p_blkg)->q, false))) +/** + * blkg_for_each_descendant_post - post-order walk of a blkg's descendants + * @d_blkg: loop cursor pointing to the current descendant + * @pos_cgrp: used for iteration + * @p_blkg: target blkg to walk descendants of + * + * Similar to blkg_for_each_descendant_pre() but performs post-order + * traversal instead. Synchronization rules are the same. + */ +#define blkg_for_each_descendant_post(d_blkg, pos_cgrp, p_blkg) \ + cgroup_for_each_descendant_post((pos_cgrp), (p_blkg)->blkcg->css.cgroup) \ + if (((d_blkg) = __blkg_lookup(cgroup_to_blkcg(pos_cgrp), \ + (p_blkg)->q, false))) + /** * blk_get_rl - get request_list to use * @q: request_queue of interest -- cgit v1.2.3