[PATCH] mm: fix CONFIG_MEMCG build for AS_KERNEL_FILE

[Boris Burkov <boris@xxxxxx>]

this needs to be folded into

mm/filemap: add AS_KERNEL_FILE

for it to build with CONFIG_MEMCG unset. Apologies for the churn.

Signed-off-by: Boris Burkov <boris@xxxxxx>
---
 include/linux/memcontrol.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 9fa3afc90dd5..e693978b2022 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -1059,6 +1059,8 @@ extern int mem_cgroup_init(void);
 
 #define MEM_CGROUP_ID_SHIFT	0
 
+#define root_mem_cgroup		(NULL)
+
 static inline struct mem_cgroup *folio_memcg(struct folio *folio)
 {
 	return NULL;
-- 
2.50.1