Merge tag 'cgroup-for-6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

Pull cgroup updates from Tejun Heo:

 - cpuset now support isolated cpus.partition type, which will enable
   dynamic CPU isolation

 - pids.peak added to remember the max number of pids used

 - holes in cgroup namespace plugged

 - internal cleanups

* tag 'cgroup-for-6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (25 commits)
  cgroup: use strscpy() is more robust and safer
  iocost_monitor: reorder BlkgIterator
  cgroup: simplify code in cgroup_apply_control
  cgroup: Make cgroup_get_from_id() prettier
  cgroup/cpuset: remove unreachable code
  cgroup: Remove CFTYPE_PRESSURE
  cgroup: Improve cftype add/rm error handling
  kselftest/cgroup: Add cpuset v2 partition root state test
  cgroup/cpuset: Update description of cpuset.cpus.partition in cgroup-v2.rst
  cgroup/cpuset: Make partition invalid if cpumask change violates exclusivity rule
  cgroup/cpuset: Relocate a code block in validate_change()
  cgroup/cpuset: Show invalid partition reason string
  cgroup/cpuset: Add a new isolated cpus.partition type
  cgroup/cpuset: Relax constraints to partition & cpus changes
  cgroup/cpuset: Allow no-task partition to have empty cpuset.cpus.effective
  cgroup/cpuset: Miscellaneous cleanups & add helper functions
  cgroup/cpuset: Enable update_tasks_cpumask() on top_cpuset
  cgroup: add pids.peak interface for pids controller
  cgroup: Remove data-race around cgrp_dfl_visible
  cgroup: Fix build failure when CONFIG_SHRINKER_DEBUG
  ...

1 files changed, 3 insertions, 10 deletions

diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index b0914aa26506..398f0bce7c21 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -575,7 +575,7 @@ static inline bool cgroup_is_descendant(struct cgroup *cgrp,
 {
 	if (cgrp->root != ancestor->root || cgrp->level < ancestor->level)
 		return false;
-	return cgrp->ancestor_ids[ancestor->level] == cgroup_id(ancestor);
+	return cgrp->ancestors[ancestor->level] == ancestor;
 }
 
 /**
@@ -592,11 +592,9 @@ static inline bool cgroup_is_descendant(struct cgroup *cgrp,
 static inline struct cgroup *cgroup_ancestor(struct cgroup *cgrp,
 					     int ancestor_level)
 {
-	if (cgrp->level < ancestor_level)
+	if (ancestor_level < 0 || ancestor_level > cgrp->level)
 		return NULL;
-	while (cgrp && cgrp->level > ancestor_level)
-		cgrp = cgroup_parent(cgrp);
-	return cgrp;
+	return cgrp->ancestors[ancestor_level];
 }
 
 /**
@@ -748,11 +746,6 @@ static inline bool task_under_cgroup_hierarchy(struct task_struct *task,
 
 static inline void cgroup_path_from_kernfs_id(u64 id, char *buf, size_t buflen)
 {}
-
-static inline struct cgroup *cgroup_get_from_id(u64 id)
-{
-	return NULL;
-}
 #endif /* !CONFIG_CGROUPS */
 
 #ifdef CONFIG_CGROUPS