pvcalls-front: read all data before closing the connection

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 <stefanos@xilinx.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

1 files changed, 1 insertions, 3 deletions

diff --git a/drivers/xen/pvcalls-front.c b/drivers/xen/pvcalls-front.c
index 77224d8f3e6f..e5d95aab2cb8 100644
--- 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;