[PATCH] cgroup: remove redundant check in cgroup_ino()

[Zefan Li <lizefan@huawei.com>]

After we implemented default unified hierarchy, cgrp->kn can never
be NULL.

Signed-off-by: Zefan Li <lizefan@huawei.com>
---
 include/linux/cgroup.h | 7 ++-----
 mm/memory-failure.c    | 2 +-
 2 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index 77a1d37..818a81f 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -532,13 +532,10 @@ static inline bool cgroup_has_tasks(struct cgroup *cgrp)
 	return !list_empty(&cgrp->cset_links);
 }
 
-/* returns ino associated with a cgroup, 0 indicates unmounted root */
+/* returns ino associated with a cgroup */
 static inline ino_t cgroup_ino(struct cgroup *cgrp)
 {
-	if (cgrp->kn)
-		return cgrp->kn->ino;
-	else
-		return 0;
+	return cgrp->kn->ino;
 }
 
 /* cft/css accessors for cftype->write() operation */
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 44c6bd2..8639f6b 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -148,7 +148,7 @@ static int hwpoison_filter_task(struct page *p)
 	ino = cgroup_ino(css->cgroup);
 	css_put(css);
 
-	if (!ino || ino != hwpoison_filter_memcg)
+	if (ino != hwpoison_filter_memcg)
 		return -EINVAL;
 
 	return 0;
-- 
1.8.0.2