io_uring/net: don't lose partial send_zc on fail

Partial zc send may end up in io_req_complete_failed(), which not only
would return invalid result but also mask out the notification leading
to lifetime issues.

Cc: stable@vger.kernel.org
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/5673285b5e83e6ceca323727b4ddaa584b5cc91e.1663668091.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

io_uring/net.c

@@ -1103,6 +1103,22 @@ void io_sendrecv_fail(struct io_kiocb *req)
 	io_req_set_res(req, res, req->cqe.flags);
 }
 
+void io_send_zc_fail(struct io_kiocb *req)
+{
+	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
+	int res = req->cqe.res;
+
+	if (req->flags & REQ_F_PARTIAL_IO) {
+		if (req->flags & REQ_F_NEED_CLEANUP) {
+			io_notif_flush(sr->notif);
+			sr->notif = NULL;
+			req->flags &= ~REQ_F_NEED_CLEANUP;
+		}
+		res = sr->done_io;
+	}
+	io_req_set_res(req, res, req->cqe.flags);
+}
+
 int io_accept_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 {
 	struct io_accept *accept = io_kiocb_to_cmd(req, struct io_accept);

io_uring/net.h

@@ -58,6 +58,7 @@ int io_connect(struct io_kiocb *req, unsigned int issue_flags);
 int io_sendzc(struct io_kiocb *req, unsigned int issue_flags);
 int io_sendzc_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe);
 void io_sendzc_cleanup(struct io_kiocb *req);
+void io_send_zc_fail(struct io_kiocb *req);
 
 void io_netmsg_cache_free(struct io_cache_entry *entry);
 #else

io_uring/opdef.c

@@ -497,6 +497,7 @@ const struct io_op_def io_op_defs[] = {
 		.issue			= io_sendzc,
 		.prep_async		= io_sendzc_prep_async,
 		.cleanup		= io_sendzc_cleanup,
+		.fail			= io_send_zc_fail,
 #else
 		.prep			= io_eopnotsupp_prep,
 #endif