From: kaf24@localhost.localdomain <kaf24@localhost.localdomain>
Date: Sat, 19 Aug 2006 09:20:08 +0000 (+0100)
Subject: [NET/BLK] back: Change the netback and blkback device drivers to allow
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~15710^2~36
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=7d0aeaacea0ac1a7855fa2cb17f8cfe3a99e0c08;p=xen.git

[NET/BLK] back: Change the netback and blkback device drivers to allow
and handle frontend state transition from "Closing" to "Initialising".
Instead of destroying the backend device then they wait for a
reconnect from the frontend.  Needed for domU kexec support, to hand over
devices from one kernel instance to the next.

Signed-off-by: Gerd Hoffmann <kraxel@suse.de>
---

diff --git a/linux-2.6-xen-sparse/drivers/xen/blkback/xenbus.c b/linux-2.6-xen-sparse/drivers/xen/blkback/xenbus.c
index ca01d15595..0f268c9e33 100644
--- a/linux-2.6-xen-sparse/drivers/xen/blkback/xenbus.c
+++ b/linux-2.6-xen-sparse/drivers/xen/blkback/xenbus.c
@@ -305,6 +305,11 @@ static void frontend_changed(struct xenbus_device *dev,
 
 	switch (frontend_state) {
 	case XenbusStateInitialising:
+		if (dev->state == XenbusStateClosing) {
+			printk("%s: %s: prepare for reconnect\n",
+			       __FUNCTION__, dev->nodename);
+			xenbus_switch_state(dev, XenbusStateInitWait);
+		}
 		break;
 
 	case XenbusStateInitialised:
diff --git a/linux-2.6-xen-sparse/drivers/xen/netback/xenbus.c b/linux-2.6-xen-sparse/drivers/xen/netback/xenbus.c
index 6bb87a636e..a0e3961234 100644
--- a/linux-2.6-xen-sparse/drivers/xen/netback/xenbus.c
+++ b/linux-2.6-xen-sparse/drivers/xen/netback/xenbus.c
@@ -234,10 +234,25 @@ static void frontend_changed(struct xenbus_device *dev,
 
 	switch (frontend_state) {
 	case XenbusStateInitialising:
+		if (dev->state == XenbusStateClosing) {
+			printk("%s: %s: prepare for reconnect\n",
+			       __FUNCTION__, dev->nodename);
+			if (be->netif) {
+				netif_disconnect(be->netif);
+				be->netif = NULL;
+			}
+			xenbus_switch_state(dev, XenbusStateInitWait);
+		}
+		break;
+
 	case XenbusStateInitialised:
 		break;
 
 	case XenbusStateConnected:
+		if (!be->netif) {
+			/* reconnect: setup be->netif */
+			backend_changed(&be->backend_watch, NULL, 0);
+		}
 		maybe_connect(be);
 		break;