From 5417c98c12f6eeb1252130bcea3b943f5e273be7 Mon Sep 17 00:00:00 2001
From: Wang Xiaojun <wangxiaojun11@huawei.com>
Date: Fri, 9 Jul 2021 16:34:53 +0800
Subject: [PATCH] f2fs: avoid to create an empty string as the extension_list

When creating a file, we need to set the temperature based on
extension_list. If the empty string is a valid extension_list,
the is_extension_exist will always returns true,
which affects the separation of hot and cold.

Signed-off-by: Wang Xiaojun <wangxiaojun11@huawei.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---
 fs/f2fs/sysfs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
index 15fe30d3aeb5c..b1725620c07d9 100644
--- a/fs/f2fs/sysfs.c
+++ b/fs/f2fs/sysfs.c
@@ -351,7 +351,7 @@ static ssize_t __sbi_store(struct f2fs_attr *a,
 			set = false;
 		}
 
-		if (strlen(name) >= F2FS_EXTENSION_LEN)
+		if (!strlen(name) || strlen(name) >= F2FS_EXTENSION_LEN)
 			return -EINVAL;
 
 		down_write(&sbi->sb_lock);