io_uring: short circuit -EAGAIN for blocking read attempt

One case was missed in the short IO retry handling, and that's hitting
-EAGAIN on a blocking attempt read (eg from io-wq context). This is a
problem on sockets that are marked as non-blocking when created, they
don't carry any REQ_F_NOWAIT information to help us terminate them
instead of perpetually retrying.

Fixes: 227c0c9673 ("io_uring: internally retry short reads")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Jens Axboe 2020-08-15 15:58:42 -07:00
parent d4e7cd36a9
commit f91daf565b

View File

@ -3186,6 +3186,8 @@ static int io_read(struct io_kiocb *req, bool force_nonblock,
ret = 0;
goto out_free;
} else if (ret == -EAGAIN) {
if (!force_nonblock)
goto done;
ret = io_setup_async_rw(req, iovec, inline_vecs, iter, false);
if (ret)
goto out_free;
@ -3195,7 +3197,8 @@ static int io_read(struct io_kiocb *req, bool force_nonblock,
}
/* read it all, or we did blocking attempt. no retry. */
if (!iov_iter_count(iter) || !force_nonblock)
if (!iov_iter_count(iter) || !force_nonblock ||
(req->file->f_flags & O_NONBLOCK))
goto done;
io_size -= ret;