diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 52b0530..5a60eec 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -4550,7 +4550,8 @@
 				&EXT4_SB(sb)->s_freeinodes_counter));
 	BUFFER_TRACE(sbh, "marking dirty");
 	ext4_superblock_csum_set(sb);
-	lock_buffer(sbh);
+	if (sync)
+		lock_buffer(sbh);
 	if (buffer_write_io_error(sbh)) {
 		/*
 		 * Oh, dear.  A previous attempt to write the
@@ -4566,8 +4567,8 @@
 		set_buffer_uptodate(sbh);
 	}
 	mark_buffer_dirty(sbh);
-	unlock_buffer(sbh);
 	if (sync) {
+		unlock_buffer(sbh);
 		error = __sync_dirty_buffer(sbh,
 			test_opt(sb, BARRIER) ? WRITE_FUA : WRITE_SYNC);
 		if (error)