Commit 2ba69707 authored by Dylan Yudaken's avatar Dylan Yudaken Committed by Jens Axboe
Browse files

io_uring: clean up io_poll_check_events return values 



The values returned are a bit confusing, where 0 and 1 have implied
meaning, so add some definitions for them.

Signed-off-by: default avatarDylan Yudaken <dylany@fb.com>
Link: https://lore.kernel.org/r/20220630091231.1456789-6-dylany@fb.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent d4e097da

io_uring/poll.c

+16 −11
Original line number Diff line number Diff line
@@ -192,13 +192,18 @@ static void io_poll_remove_entries(struct io_kiocb *req) 
	rcu_read_unlock();

}



enum {

	IOU_POLL_DONE = 0,

	IOU_POLL_NO_ACTION = 1,

};



/*

 * All poll tw should go through this. Checks for poll events, manages

 * references, does rewait, etc.

 *

 * Returns a negative error on failure. >0 when no action require, which is

 * either spurious wakeup or multishot CQE is served. 0 when it's done with

 * the request, then the mask is stored in req->cqe.res.

 * Returns a negative error on failure. IOU_POLL_NO_ACTION when no action require,

 * which is either spurious wakeup or multishot CQE is served.

 * IOU_POLL_DONE when it's done with the request, then the mask is stored in req->cqe.res.

 */

static int io_poll_check_events(struct io_kiocb *req, bool *locked)

{
@@ -214,10 +219,11 @@ static int io_poll_check_events(struct io_kiocb *req, bool *locked) 


		/* tw handler should be the owner, and so have some references */

		if (WARN_ON_ONCE(!(v & IO_POLL_REF_MASK)))

			return 0;

			return IOU_POLL_DONE;

		if (v & IO_POLL_CANCEL_FLAG)

			return -ECANCELED;



		/* the mask was stashed in __io_poll_execute */

		if (!req->cqe.res) {

			struct poll_table_struct pt = { ._key = req->apoll_events };

			req->cqe.res = vfs_poll(req->file, &pt) & req->apoll_events;
@@ -226,7 +232,7 @@ static int io_poll_check_events(struct io_kiocb *req, bool *locked) 
		if ((unlikely(!req->cqe.res)))

			continue;

		if (req->apoll_events & EPOLLONESHOT)

			return 0;

			return IOU_POLL_DONE;



		/* multishot, just fill a CQE and proceed */

		if (!(req->flags & REQ_F_APOLL_MULTISHOT)) {
@@ -238,7 +244,7 @@ static int io_poll_check_events(struct io_kiocb *req, bool *locked) 
				return -ECANCELED;

		} else {

			ret = io_poll_issue(req, locked);

			if (ret)

			if (ret < 0)

				return ret;

		}
@@ -248,7 +254,7 @@ static int io_poll_check_events(struct io_kiocb *req, bool *locked) 
		 */

	} while (atomic_sub_return(v & IO_POLL_REF_MASK, &req->poll_refs));



	return 1;

	return IOU_POLL_NO_ACTION;

}



static void io_poll_task_func(struct io_kiocb *req, bool *locked)
@@ -256,12 +262,11 @@ static void io_poll_task_func(struct io_kiocb *req, bool *locked) 
	int ret;



	ret = io_poll_check_events(req, locked);

	if (ret > 0)

	if (ret == IOU_POLL_NO_ACTION)

		return;



	if (!ret) {

	if (ret == IOU_POLL_DONE) {

		struct io_poll *poll = io_kiocb_to_cmd(req);



		req->cqe.res = mangle_poll(req->cqe.res & poll->events);

	} else {

		req->cqe.res = ret;
@@ -280,7 +285,7 @@ static void io_apoll_task_func(struct io_kiocb *req, bool *locked) 
	int ret;



	ret = io_poll_check_events(req, locked);

	if (ret > 0)

	if (ret == IOU_POLL_NO_ACTION)

		return;



	io_poll_remove_entries(req);