Commit ab673c1b authored by Jens Axboe's avatar Jens Axboe
Browse files

io_uring/waitid: use io_waitid_remove_wq() consistently 



Use it everywhere that the wait_queue_entry is removed from the head,
and be a bit more cautious in zeroing out iw->head whenever the entry is
removed from the list.

Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent a48c0cbf

io_uring/waitid.c

+11 −4
Original line number Diff line number Diff line
@@ -179,18 +179,18 @@ bool io_waitid_remove_all(struct io_ring_ctx *ctx, struct io_uring_task *tctx, 
static inline bool io_waitid_drop_issue_ref(struct io_kiocb *req)

{

	struct io_waitid *iw = io_kiocb_to_cmd(req, struct io_waitid);

	struct io_waitid_async *iwa = req->async_data;



	if (!atomic_sub_return(1, &iw->refs))

		return false;



	io_waitid_remove_wq(req);



	/*

	 * Wakeup triggered, racing with us. It was prevented from

	 * completing because of that, queue up the tw to do that.

	 */

	req->io_task_work.func = io_waitid_cb;

	io_req_task_work_add(req);

	remove_wait_queue(iw->head, &iwa->wo.child_wait);

	return true;

}
@@ -245,6 +245,7 @@ static int io_waitid_wait(struct wait_queue_entry *wait, unsigned mode, 
		return 0;



	list_del_init(&wait->entry);

	iw->head = NULL;



	/* cancel is in progress */

	if (atomic_fetch_inc(&iw->refs) & IO_WAITID_REF_MASK)
@@ -271,6 +272,7 @@ int io_waitid_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) 
	iw->which = READ_ONCE(sqe->len);

	iw->upid = READ_ONCE(sqe->fd);

	iw->options = READ_ONCE(sqe->file_index);

	iw->head = NULL;

	iw->infop = u64_to_user_ptr(READ_ONCE(sqe->addr2));

	return 0;

}
@@ -301,11 +303,16 @@ int io_waitid(struct io_kiocb *req, unsigned int issue_flags) 
	 * callback.

	 */

	io_ring_submit_lock(ctx, issue_flags);



	/*

	 * iw->head is valid under the ring lock, and as long as the request

	 * is on the waitid_list where cancelations may find it.

	 */

	iw->head = &current->signal->wait_chldexit;

	hlist_add_head(&req->hash_node, &ctx->waitid_list);



	init_waitqueue_func_entry(&iwa->wo.child_wait, io_waitid_wait);

	iwa->wo.child_wait.private = req->tctx->task;

	iw->head = &current->signal->wait_chldexit;

	add_wait_queue(iw->head, &iwa->wo.child_wait);



	ret = __do_wait(&iwa->wo);
@@ -328,7 +335,7 @@ int io_waitid(struct io_kiocb *req, unsigned int issue_flags) 
	}



	hlist_del_init(&req->hash_node);

	remove_wait_queue(iw->head, &iwa->wo.child_wait);

	io_waitid_remove_wq(req);

	ret = io_waitid_finish(req, ret);



	io_ring_submit_unlock(ctx, issue_flags);