From: Stefano Stabellini <sstabellini@kernel.org>
Date: Fri, 21 Dec 2018 23:06:29 +0000 (-0800)
Subject: pvcalls-front: read all data before closing the connection
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=b79470b64fa9266948d1ce8d825ced94c4f63293;p=linux.git

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>
---

diff --git a/drivers/xen/pvcalls-front.c b/drivers/xen/pvcalls-front.c
index 77224d8f3e6fe..e5d95aab2cb80 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;