Commit c5b85625 authored by Jens Axboe's avatar Jens Axboe
Browse files

io_uring: allow O_NONBLOCK async retry 



We can assume that O_NONBLOCK is always honored, even if we don't
have a ->read/write_iter() for the file type. Also unify the read/write
checking for allowing async punt, having the write side factoring in the
REQ_F_NOWAIT flag as well.

Cc: stable@vger.kernel.org
Fixes: 490e8967 ("io_uring: only force async punt if poll based retry can't handle it")
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent f5fa38c5

fs/io_uring.c

+7 −3
Original line number Original line Diff line number Diff line
@@ -2061,6 +2061,10 @@ static bool io_file_supports_async(struct file *file, int rw) 
	if (S_ISREG(mode) && file->f_op != &io_uring_fops)

	if (S_ISREG(mode) && file->f_op != &io_uring_fops)

		return true;

		return true;





	/* any ->read/write should understand O_NONBLOCK */

	if (file->f_flags & O_NONBLOCK)

		return true;



	if (!(file->f_mode & FMODE_NOWAIT))

	if (!(file->f_mode & FMODE_NOWAIT))

		return false;

		return false;
@@ -2103,8 +2107,7 @@ static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe, 
		kiocb->ki_ioprio = get_current_ioprio();

		kiocb->ki_ioprio = get_current_ioprio();





	/* don't allow async punt if RWF_NOWAIT was requested */

	/* don't allow async punt if RWF_NOWAIT was requested */

	if ((kiocb->ki_flags & IOCB_NOWAIT) ||

	if (kiocb->ki_flags & IOCB_NOWAIT)

	    (req->file->f_flags & O_NONBLOCK))

		req->flags |= REQ_F_NOWAIT;

		req->flags |= REQ_F_NOWAIT;





	if (force_nonblock)

	if (force_nonblock)
@@ -2745,7 +2748,8 @@ static int io_write(struct io_kiocb *req, bool force_nonblock) 
			if (ret)

			if (ret)

				goto out_free;

				goto out_free;

			/* any defer here is final, must blocking retry */

			/* any defer here is final, must blocking retry */

			if (!file_can_poll(req->file))

			if (!(req->flags & REQ_F_NOWAIT) &&

			    !file_can_poll(req->file))

				req->flags |= REQ_F_MUST_PUNT;

				req->flags |= REQ_F_MUST_PUNT;

			return -EAGAIN;

			return -EAGAIN;

		}

		}