From: Steven Smith <ssmith@weybridge.uk.xensource.com>
Date: Thu, 28 May 2009 10:54:19 +0000 (+0100)
Subject: patch CA-9002-blktap-plug
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=652b52d2c10a3eaae1e13ea66aec6ad3f11a75f6;p=people%2Fssmith%2Fnc2-2.6.27.bak%2F.git

patch CA-9002-blktap-plug
---

diff --git a/drivers/xen/blktap/xenbus.c b/drivers/xen/blktap/xenbus.c
index 1291d557..6b25526a 100644
--- a/drivers/xen/blktap/xenbus.c
+++ b/drivers/xen/blktap/xenbus.c
@@ -415,6 +415,10 @@ static void blktap_reconnect(struct backend_info *be)
 	be->shutdown_signalled = 0;
 
 	xenbus_switch_state(dev, XenbusStateInitWait);
+
+	err = xenbus_write(XBT_NIL, be->nodename, "start-tapdisk", "");
+	if (err)
+		xenbus_dev_fatal(be->dev, err, "restarting tapdisk");
 }
 
 static void tap_update_blkif_status(blkif_t *blkif)
@@ -517,6 +521,11 @@ static int blktap_probe(struct xenbus_device *dev,
 	err = xenbus_switch_state(dev, XenbusStateInitWait);
 	if (err)
 		goto fail;
+
+	err = xenbus_write(XBT_NIL, dev->nodename, "start-tapdisk", "");
+	if (err)
+		goto fail;
+
 	return 0;
 
 fail:
@@ -554,6 +563,12 @@ static void tap_backend_changed(struct xenbus_watch *watch,
 		return;
 	}
 
+	if (dev->state != XenbusStateInitWait) {
+		WPRINTK("%s: tapdisk ready, but blktap at %s\n",
+			__func__, xenbus_strstate(dev->state));
+		return;
+	}
+
 	err = xenbus_gather(XBT_NIL, dev->nodename, "sectors", "%llu", 
 			    &be->blkif->sectors, NULL);
 	if (err) {