[PATCH -next v3 3/5] ext4: get buffer head before read_mmp_block

[Ye Bin <yebin10@huawei.com>]

There is only pass NULL 'bh' in ext4_multi_mount_protect,
So just call sb_getblk get buffer head fisrt, and we will
simplify read_mmp_block function.

Signed-off-by: Ye Bin <yebin10@huawei.com>
---
 fs/ext4/mmp.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/fs/ext4/mmp.c b/fs/ext4/mmp.c
index 4af8b99ade84..6ac6aacd8fa5 100644
--- a/fs/ext4/mmp.c
+++ b/fs/ext4/mmp.c
@@ -295,6 +295,10 @@ int ext4_multi_mount_protect(struct super_block *sb,
 		goto failed;
 	}
 
+	bh = sb_getblk(sb, mmp_block);
+	if (bh)
+		goto failed;
+
 	retval = read_mmp_block(sb, &bh, mmp_block);
 	if (retval)
 		goto failed;
-- 
2.31.1