pvcalls-front: read all data before closing the connection

sstabellini · Boris Ostrovsky · commit b79470b64fa9 · 2019-01-02T10:59:48.000-05:00
When a connection is closing in_error is set to ENOTCONN. There could
still be outstanding data on the ring left by the backend. Before
closing the connection on the frontend side, drain the ring.

Signed-off-by: Stefano Stabellini &lt;stefanos@xilinx.com&gt;
Reviewed-by: Boris Ostrovsky &lt;boris.ostrovsky@oracle.com&gt;
Signed-off-by: Boris Ostrovsky &lt;boris.ostrovsky@oracle.com&gt;
diff --git a/drivers/xen/pvcalls-front.c b/drivers/xen/pvcalls-front.c
@@ -560,15 +560,13 @@ static int __read_ring(struct pvcalls_data_intf *intf,
 	error = intf->in_error;
 	/* get pointers before reading from the ring */
 	virt_rmb();
-	if (error < 0)
-		return error;
 
 	size = pvcalls_queued(prod, cons, array_size);
 	masked_prod = pvcalls_mask(prod, array_size);
 	masked_cons = pvcalls_mask(cons, array_size);
 
 	if (size == 0)
-		return 0;
+		return error ?: size;
 
 	if (len > size)
 		len = size;
