Commit 7ba89d2a authored by Jens Axboe's avatar Jens Axboe
Browse files

io_uring: ensure recv and recvmsg handle MSG_WAITALL correctly 



We currently don't attempt to get the full asked for length even if
MSG_WAITALL is set, if we get a partial receive. If we do see a partial
receive, then just note how many bytes we did and return -EAGAIN to
get it retried.

The iov is advanced appropriately for the vector based case, and we
manually bump the buffer and remainder for the non-vector case.

Cc: stable@vger.kernel.org
Reported-by: default avatarConstantine Gavrilov <constantine.gavrilov@gmail.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 4d55f238

fs/io_uring.c

+28 −0
Original line number Diff line number Diff line
@@ -612,6 +612,7 @@ struct io_sr_msg { 
	int				msg_flags;

	int				bgid;

	size_t				len;

	size_t				done_io;

};



struct io_open {
@@ -5417,12 +5418,21 @@ static int io_recvmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) 
	if (req->ctx->compat)

		sr->msg_flags |= MSG_CMSG_COMPAT;

#endif

	sr->done_io = 0;

	return 0;

}



static bool io_net_retry(struct socket *sock, int flags)

{

	if (!(flags & MSG_WAITALL))

		return false;

	return sock->type == SOCK_STREAM || sock->type == SOCK_SEQPACKET;

}



static int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags)

{

	struct io_async_msghdr iomsg, *kmsg;

	struct io_sr_msg *sr = &req->sr_msg;

	struct socket *sock;

	struct io_buffer *kbuf;

	unsigned flags;
@@ -5465,6 +5475,10 @@ static int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags) 
			return io_setup_async_msg(req, kmsg);

		if (ret == -ERESTARTSYS)

			ret = -EINTR;

		if (ret > 0 && io_net_retry(sock, flags)) {

			sr->done_io += ret;

			return io_setup_async_msg(req, kmsg);

		}

		req_set_fail(req);

	} else if ((flags & MSG_WAITALL) && (kmsg->msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))) {

		req_set_fail(req);
@@ -5474,6 +5488,10 @@ static int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags) 
	if (kmsg->free_iov)

		kfree(kmsg->free_iov);

	req->flags &= ~REQ_F_NEED_CLEANUP;

	if (ret >= 0)

		ret += sr->done_io;

	else if (sr->done_io)

		ret = sr->done_io;

	__io_req_complete(req, issue_flags, ret, io_put_kbuf(req, issue_flags));

	return 0;

}
@@ -5524,12 +5542,22 @@ static int io_recv(struct io_kiocb *req, unsigned int issue_flags) 
			return -EAGAIN;

		if (ret == -ERESTARTSYS)

			ret = -EINTR;

		if (ret > 0 && io_net_retry(sock, flags)) {

			sr->len -= ret;

			sr->buf += ret;

			sr->done_io += ret;

			return -EAGAIN;

		}

		req_set_fail(req);

	} else if ((flags & MSG_WAITALL) && (msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))) {

out_free:

		req_set_fail(req);

	}



	if (ret >= 0)

		ret += sr->done_io;

	else if (sr->done_io)

		ret = sr->done_io;

	__io_req_complete(req, issue_flags, ret, io_put_kbuf(req, issue_flags));

	return 0;

}