cgroup: remove sane_behavior support on non-default hierarchies

sane_behavior has been used as a development vehicle for the default
unified hierarchy.  Now that the default hierarchy is in place, the
flag became redundant and confusing as its usage is allowed on all
hierarchies.  There are gonna be either the default hierarchy or
legacy ones.  Let's make that clear by removing sane_behavior support
on non-default hierarchies.

This patch replaces cgroup_sane_behavior() with cgroup_on_dfl().  The
comment on top of CGRP_ROOT_SANE_BEHAVIOR is moved to on top of
cgroup_on_dfl() with sane_behavior specific part dropped.

On the default and legacy hierarchies w/o sane_behavior, this
shouldn't cause any behavior differences.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Acked-by: Li Zefan <lizefan@huawei.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>

1 files changed, 3 insertions, 3 deletions

diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index 3fdb21a390c1..9273d0969ebd 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -412,13 +412,13 @@ static void throtl_pd_init(struct blkcg_gq *blkg)
         int rw;
 
         /*
-         * If sane_hierarchy is enabled, we switch to properly hierarchical
+         * If on the default hierarchy, we switch to properly hierarchical
          * behavior where limits on a given throtl_grp are applied to the
          * whole subtree rather than just the group itself.  e.g. If 16M
          * read_bps limit is set on the root group, the whole system can't
          * exceed 16M for the device.
          *
-         * If sane_hierarchy is not enabled, the broken flat hierarchy
+         * If not on the default hierarchy, the broken flat hierarchy
          * behavior is retained where all throtl_grps are treated as if
          * they're all separate root groups right below throtl_data.
          * Limits of a group don't interact with limits of other groups
@@ -426,7 +426,7 @@ static void throtl_pd_init(struct blkcg_gq *blkg)
          */
         parent_sq = &td->service_queue;
 
-        if (cgroup_sane_behavior(blkg->blkcg->css.cgroup) && blkg->parent)
+        if (cgroup_on_dfl(blkg->blkcg->css.cgroup) && blkg->parent)
                 parent_sq = &blkg_to_tg(blkg->parent)->service_queue;
 
         throtl_service_queue_init(&tg->service_queue, parent_sq);