Commit 3a089881 authored by Jens Axboe's avatar Jens Axboe
Browse files

io_uring/net: only retry recv bundle for a full transfer 

If a shorter than assumed transfer was seen, a partial buffer will have
been filled. For that case it isn't sane to attempt to fill more into
the bundle before posting a completion, as that will cause a gap in
the received data.

Check if the iterator has hit zero and only allow to continue a bundle
operation if that is the case.

Also ensure that for putting finished buffers, only the current transfer
is accounted. Otherwise too many buffers may be put for a short transfer.

Link: https://github.com/axboe/liburing/issues/1409


Cc: stable@vger.kernel.org
Fixes: 7c71a0af ("io_uring/net: improve recv bundles")
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent a7d755ed

io_uring/net.c

+10 −4
Original line number Diff line number Diff line
@@ -827,18 +827,24 @@ static inline bool io_recv_finish(struct io_kiocb *req, int *ret, 
		cflags |= IORING_CQE_F_SOCK_NONEMPTY;



	if (sr->flags & IORING_RECVSEND_BUNDLE) {

		cflags |= io_put_kbufs(req, *ret, io_bundle_nbufs(kmsg, *ret),

		size_t this_ret = *ret - sr->done_io;



		cflags |= io_put_kbufs(req, *ret, io_bundle_nbufs(kmsg, this_ret),

				      issue_flags);

		if (sr->retry)

			cflags = req->cqe.flags | (cflags & CQE_F_MASK);

		/* bundle with no more immediate buffers, we're done */

		if (req->flags & REQ_F_BL_EMPTY)

			goto finish;

		/* if more is available, retry and append to this one */

		if (!sr->retry && kmsg->msg.msg_inq > 0 && *ret > 0) {

		/*

		 * If more is available AND it was a full transfer, retry and

		 * append to this one

		 */

		if (!sr->retry && kmsg->msg.msg_inq > 0 && this_ret > 0 &&

		    !iov_iter_count(&kmsg->msg.msg_iter)) {

			req->cqe.flags = cflags & ~CQE_F_MASK;

			sr->len = kmsg->msg.msg_inq;

			sr->done_io += *ret;

			sr->done_io += this_ret;

			sr->retry = true;

			return false;

		}