io_uring: allow O_NONBLOCK async retry (c5b85625) · Commits · 戴 / test

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: ("io_uring: only force async punt if poll based retry can't handle it") Signed-off-by:

Jens Axboe <axboe@kernel.dk>

fs/io_uring.c

+7 −3

Original line number	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)
		return true;

		/* any ->read/write should understand O_NONBLOCK */
		if (file->f_flags & O_NONBLOCK)
		return true;

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

		/* don't allow async punt if RWF_NOWAIT was requested */
		if ((kiocb->ki_flags & IOCB_NOWAIT) \|\|
		(req->file->f_flags & O_NONBLOCK))
		if (kiocb->ki_flags & IOCB_NOWAIT)
		req->flags \|= REQ_F_NOWAIT;

		if (force_nonblock)
		@@ -2745,7 +2748,8 @@ copy_iov:
		if (ret)
		goto out_free;
		/* 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;
		return -EAGAIN;
		}

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