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From:   Qi Zheng <zhengqi.arch@bytedance.com>
To:     dan.carpenter@linaro.org, akpm@linux-foundation.org
Cc:     david@fromorbit.com, tkhai@ya.ru, vbabka@suse.cz,
        roman.gushchin@linux.dev, djwong@kernel.org, brauner@kernel.org,
        paulmck@kernel.org, tytso@mit.edu, steven.price@arm.com,
        cel@kernel.org, senozhatsky@chromium.org, yujie.liu@intel.com,
        gregkh@linuxfoundation.org, muchun.song@linux.dev,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        linux-fsdevel@vger.kernel.org,
        Qi Zheng <zhengqi.arch@bytedance.com>
Subject: [PATCH] fixup: mm: shrinker: add a secondary array for shrinker_info::{map, nr_deferred}
Date:   Thu, 28 Sep 2023 22:15:17 +0800
Message-Id: <20230928141517.12164-1-zhengqi.arch@bytedance.com>
In-Reply-To: <20230911094444.68966-41-zhengqi.arch@bytedance.com>
References: <20230911094444.68966-41-zhengqi.arch@bytedance.com>
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Dan Carpenter reported the following bug:

```
The patch b6884b5f15cf: "mm: shrinker: add a secondary array for
shrinker_info::{map, nr_deferred}" from Sep 11, 2023 (linux-next),
leads to the following Smatch static checker warning:

	mm/shrinker.c:100 alloc_shrinker_info()
	warn: inconsistent returns '&shrinker_mutex'.
```

To fix it, unlock the &shrinker_rwsem before the call to
free_shrinker_info().

Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/linux-mm/f960ae49-078c-4c00-9516-da31fc1a17d6@moroto.mountain/
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
---
 mm/shrinker.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/mm/shrinker.c b/mm/shrinker.c
index 893079806553..e9644cda80b5 100644
--- a/mm/shrinker.c
+++ b/mm/shrinker.c
@@ -95,6 +95,7 @@ int alloc_shrinker_info(struct mem_cgroup *memcg)
 	return ret;
 
 err:
+	up_write(&shrinker_rwsem);
 	free_shrinker_info(memcg);
 	return -ENOMEM;
 }
-- 
2.30.2