From: Chris Lalancette <clalance@redhat.com>
Date: Thu, 5 Mar 2009 14:11:37 +0100
Subject: [xen] only recover connected devices on resume
Message-id: 49AFCF89.3000104@redhat.com
O-Subject: [RHEL5.4 PATCH 1/2]: Only recover connected devices on resume
Bugzilla: 396621
RH-Acked-by: Don Dutile <ddutile@redhat.com>
RH-Acked-by: Rik van Riel <riel@redhat.com>

This patch is strictly a bugfix in the save/resume path, noticed while testing
this patch series.  What was happening was that I was getting a panic on resume
for an FV guest that had PV-on-HVM drivers loaded, but not in use.  This is
because on the resume path we were freeing an info structure that never existed
in the first place.  This patch is just a re-diff of upstream xen-unstable c/s
12526, and fixes the problem in testing.

diff --git a/drivers/xen/blkfront/blkfront.c b/drivers/xen/blkfront/blkfront.c
index 0798ad7..f8cba8f 100644
--- a/drivers/xen/blkfront/blkfront.c
+++ b/drivers/xen/blkfront/blkfront.c
@@ -144,10 +144,10 @@ static int blkfront_resume(struct xenbus_device *dev)
 
 	DPRINTK("blkfront_resume: %s\n", dev->nodename);
 
-	blkif_free(info, 1);
+	blkif_free(info, info->connected == BLKIF_STATE_CONNECTED);
 
 	err = talk_to_backend(dev, info);
-	if (!err)
+	if (info->connected == BLKIF_STATE_SUSPENDED && !err)
 		blkif_recover(info);
 
 	return err;