ext4_sync_file    668 fs/ext4/dir.c  	.fsync		= ext4_sync_file,
ext4_sync_file   2520 fs/ext4/ext4.h extern int ext4_sync_file(struct file *, loff_t, loff_t, int);
ext4_sync_file    526 fs/ext4/file.c 	.fsync		= ext4_sync_file,