/* PageLocked prevents anyone from starting writeback of a page which is under read I/O (PageWriteback is only ever set against a locked page).  */
static void mark_buffer_async_read(struct buffer_head *bh)
/* PageLocked prevents anyone from starting writeback of a page which is under read I/O (PageWriteback is only ever set against a locked page).  */
static void mark_buffer_async_read(struct buffer_head *bh)
{
	bh->b_end_io = end_buffer_async_read;
	set_buffer_async_read(bh);
}