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From:   Dinghao Liu <dinghao.liu@zju.edu.cn>
To:     dinghao.liu@zju.edu.cn, kjlu@umn.edu
Cc:     pakki001@umn.edu, Chris Mason <clm@fb.com>,
        Josef Bacik <josef@toxicpanda.com>,
        David Sterba <dsterba@suse.com>, linux-btrfs@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH] fs: Fix a missing check bug
Date:   Sat,  7 Dec 2019 22:41:25 +0800
Message-Id: <20191207144126.14320-1-dinghao.liu@zju.edu.cn>
MIME-Version: 1.0
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Sender: linux-kernel-owner@vger.kernel.org
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The return value of link_free_space(ctl, info) is checked out-sync. Only one branch of an if statement checks this return value after WARN_ON(ret).

Since this path pair is similar in semantic, there might be a missing check bug.

Fix this by simply adding a check on ret.

Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn>
---
 fs/btrfs/free-space-cache.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index 3283da419200..acbb3a59d344 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -2437,6 +2437,8 @@ int btrfs_remove_free_space(struct btrfs_block_group *block_group,
 			if (info->bytes) {
 				ret = link_free_space(ctl, info);
 				WARN_ON(ret);
+				if (ret)
+					goto out_lock;
 			} else {
 				kmem_cache_free(btrfs_free_space_cachep, info);
 			}
-- 
2.21.0 (Apple Git-122)