Commit 355afaeb authored by Jens Axboe's avatar Jens Axboe
Browse files

io_uring: no read/write-retry on -EAGAIN error and O_NONBLOCK marked file 



Actually two things that need fixing up here:

- The io_rw_reissue() -EAGAIN retry is explicit to block devices and
  regular files, so don't ever attempt to do that on other types of
  files.

- If we hit -EAGAIN on a nonblock marked file, don't arm poll handler for
  it. It should just complete with -EAGAIN.

Cc: stable@vger.kernel.org
Reported-by: default avatarNorman Maurer <norman.maurer@googlemail.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 95d1c8e5

fs/io_uring.c

+10 −0
Original line number Diff line number Diff line
@@ -2300,8 +2300,11 @@ end_req: 
static bool io_rw_reissue(struct io_kiocb *req, long res)

{

#ifdef CONFIG_BLOCK

	umode_t mode = file_inode(req->file)->i_mode;

	int ret;



	if (!S_ISBLK(mode) && !S_ISREG(mode))

		return false;

	if ((res != -EAGAIN && res != -EOPNOTSUPP) || io_wq_current_is_worker())

		return false;
@@ -3146,6 +3149,9 @@ static int io_read(struct io_kiocb *req, bool force_nonblock, 
		/* IOPOLL retry should happen for io-wq threads */

		if (!force_nonblock && !(req->ctx->flags & IORING_SETUP_IOPOLL))

			goto done;

		/* no retry on NONBLOCK marked file */

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

			goto done;

		/* some cases will consume bytes even on error returns */

		iov_iter_revert(iter, iov_count - iov_iter_count(iter));

		ret = io_setup_async_rw(req, iovec, inline_vecs, iter, false);
@@ -3287,10 +3293,14 @@ static int io_write(struct io_kiocb *req, bool force_nonblock, 
	 */

	if (ret2 == -EOPNOTSUPP && (kiocb->ki_flags & IOCB_NOWAIT))

		ret2 = -EAGAIN;

	/* no retry on NONBLOCK marked file */

	if (ret2 == -EAGAIN && (req->file->f_flags & O_NONBLOCK))

		goto done;

	if (!force_nonblock || ret2 != -EAGAIN) {

		/* IOPOLL retry should happen for io-wq threads */

		if ((req->ctx->flags & IORING_SETUP_IOPOLL) && ret2 == -EAGAIN)

			goto copy_iov;

done:

		kiocb_done(kiocb, ret2, cs);

	} else {

copy_iov:

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