From: Lin Feng <linf@wangsu.com>

Date: Thu, 16 Jun 2022 18:38:30 +0800

Subject: cgroup.c: add helper __cset_cgroup_from_root to cleanup duplicated

 codes

Git-commit: e210a89f5b07680fe21d21e846e6817346c5ba3b

Patch-mainline: v6.0-rc1

References: bsc#1203906

No funtionality change, but save us some lines.

Signed-off-by: Lin Feng <linf@wangsu.com>

Acked-by: Mukesh Ojha <quic_mojha@quicinc.com>

Signed-off-by: Tejun Heo <tj@kernel.org>

Acked-by: Michal Koutný <mkoutny@suse.com>

---

 kernel/cgroup/cgroup.c | 58 +++++++++++++++++++++++---------------------------

 1 file changed, 27 insertions(+), 31 deletions(-)

diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c

index 90a654cb8a1e..4b67e6da6bf2 100644

--- a/kernel/cgroup/cgroup.c

+++ b/kernel/cgroup/cgroup.c

@@ -1376,6 +1376,31 @@ static void cgroup_destroy_root(struct cgroup_root *root)

 	cgroup_free_root(root);

 }

+static inline struct cgroup *__cset_cgroup_from_root(struct css_set *cset,

+					    struct cgroup_root *root)

+{

+	struct cgroup *res_cgroup = NULL;

+

+	if (cset == &init_css_set) {

+		res_cgroup = &root->cgrp;

+	} else if (root == &cgrp_dfl_root) {

+		res_cgroup = cset->dfl_cgrp;

+	} else {

+		struct cgrp_cset_link *link;

+

+		list_for_each_entry(link, &cset->cgrp_links, cgrp_link) {

+			struct cgroup *c = link->cgrp;

+

+			if (c->root == root) {

+				res_cgroup = c;

+				break;

+			}

+		}

+	}

+

+	return res_cgroup;

+}

+

 /*

  * look up cgroup associated with current task's cgroup namespace on the

  * specified hierarchy

@@ -1391,22 +1416,8 @@ current_cgns_cgroup_from_root(struct cgroup_root *root)

 	rcu_read_lock();

 	cset = current->nsproxy->cgroup_ns->root_cset;

-	if (cset == &init_css_set) {

-		res = &root->cgrp;

-	} else if (root == &cgrp_dfl_root) {

-		res = cset->dfl_cgrp;

-	} else {

-		struct cgrp_cset_link *link;

-

-		list_for_each_entry(link, &cset->cgrp_links, cgrp_link) {

-			struct cgroup *c = link->cgrp;

+	res = __cset_cgroup_from_root(cset, root);

-			if (c->root == root) {

-				res = c;

-				break;

-			}

-		}

-	}

 	rcu_read_unlock();

 	BUG_ON(!res);

@@ -1422,22 +1433,7 @@ static struct cgroup *cset_cgroup_from_root(struct css_set *cset,

 	lockdep_assert_held(&cgroup_mutex);

 	lockdep_assert_held(&css_set_lock);

-	if (cset == &init_css_set) {

-		res = &root->cgrp;

-	} else if (root == &cgrp_dfl_root) {

-		res = cset->dfl_cgrp;

-	} else {

-		struct cgrp_cset_link *link;

-

-		list_for_each_entry(link, &cset->cgrp_links, cgrp_link) {

-			struct cgroup *c = link->cgrp;

-

-			if (c->root == root) {

-				res = c;

-				break;

-			}

-		}

-	}

+	res = __cset_cgroup_from_root(cset, root);

 	BUG_ON(!res);

 	return res;