From: wangxuewen <18810879172@163.com>
Date: Wed, 13 May 2026 07:52:14 +0000 (+0800)
Subject: mm/shrinker: simplify shrinker_memcg_alloc() using guard()
X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=12ccf2bef35c4f42f7bf433f7ab699ec103e7f53;p=thirdparty%2Flinux.git

mm/shrinker: simplify shrinker_memcg_alloc() using guard()

Use guard(mutex) to automatically handle shrinker_mutex locking and
unlocking in shrinker_memcg_alloc().  This removes the explicit
mutex_unlock() call, the goto-based error path, and the redundant ret
variable, resulting in cleaner and more concise code.

Link: https://lore.kernel.org/20260513075214.2655710-1-18810879172@163.com
Signed-off-by: wangxuewen <wangxuewen@kylinos.cn>
Acked-by: Muchun Song <muchun.song@linux.dev>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Xuewen Wang <wangxuewen@kylinos.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

diff --git a/mm/shrinker.c b/mm/shrinker.c
index 49256f81199f..7082d01c8c9d 100644
--- a/mm/shrinker.c
+++ b/mm/shrinker.c
@@ -216,29 +216,26 @@ static DEFINE_IDR(shrinker_idr);
 
 static int shrinker_memcg_alloc(struct shrinker *shrinker)
 {
-	int id, ret = -ENOMEM;
+	int id;
 
 	if (mem_cgroup_disabled())
 		return -ENOSYS;
 	if (mem_cgroup_kmem_disabled() && !(shrinker->flags & SHRINKER_NONSLAB))
 		return -ENOSYS;
 
-	mutex_lock(&shrinker_mutex);
+	guard(mutex)(&shrinker_mutex);
 	id = idr_alloc(&shrinker_idr, shrinker, 0, 0, GFP_KERNEL);
 	if (id < 0)
-		goto unlock;
+		return id;
 
 	if (id >= shrinker_nr_max) {
 		if (expand_shrinker_info(id)) {
 			idr_remove(&shrinker_idr, id);
-			goto unlock;
+			return -ENOMEM;
 		}
 	}
 	shrinker->id = id;
-	ret = 0;
-unlock:
-	mutex_unlock(&shrinker_mutex);
-	return ret;
+	return 0;
 }
 
 static void shrinker_memcg_remove(struct shrinker *shrinker)