f2fs_sync_file   1058 fs/f2fs/dir.c  	.fsync		= f2fs_sync_file,
f2fs_sync_file   2925 fs/f2fs/f2fs.h int f2fs_sync_file(struct file *file, loff_t start, loff_t end, int datasync);
f2fs_sync_file   3466 fs/f2fs/file.c 	.fsync		= f2fs_sync_file,