struct io_poll_table {
struct poll_table_struct pt;
struct io_kiocb *req;
+ int nr_entries;
int error;
};
struct io_kiocb *req = pt->req;
/*
- * If poll->head is already set, it's because the file being polled
- * uses multiple waitqueues for poll handling (eg one for read, one
- * for write). Setup a separate io_poll_iocb if this happens.
+ * The file being polled uses multiple waitqueues for poll handling
+ * (e.g. one for read, one for write). Setup a separate io_poll_iocb
+ * if this happens.
*/
- if (unlikely(poll->head)) {
+ if (unlikely(pt->nr_entries)) {
struct io_poll_iocb *poll_one = poll;
/* already have a 2nd entry, fail a third attempt */
*poll_ptr = poll;
}
- pt->error = 0;
+ pt->nr_entries++;
poll->head = head;
if (poll->events & EPOLLEXCLUSIVE)
ipt->pt._key = mask;
ipt->req = req;
- ipt->error = -EINVAL;
+ ipt->error = 0;
+ ipt->nr_entries = 0;
mask = vfs_poll(req->file, &ipt->pt) & poll->events;
+ if (unlikely(!ipt->nr_entries) && !ipt->error)
+ ipt->error = -EINVAL;
spin_lock_irq(&ctx->completion_lock);
if (likely(poll->head)) {