From 1fa73be6be65028a7543bba8f14474b42e064a1b Mon Sep 17 00:00:00 2001
From: "K. Y. Srinivasan" <ksrinivasan@novell.com>
Date: Thu, 11 Mar 2010 13:42:26 -0800
Subject: [PATCH] xen/front: Propagate changed size of VBDs

Support dynamic resizing of virtual block devices. This patch supports
both file backed block devices as well as physical devices that can be
dynamically resized on the host side.

Signed-off-by: K. Y. Srinivasan <ksrinivasan@novell.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
---
 drivers/block/xen-blkfront.c | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 60006b730872..f47b0961fab1 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -930,9 +930,24 @@ static void blkfront_connect(struct blkfront_info *info)
 	unsigned int binfo;
 	int err;
 
-	if ((info->connected == BLKIF_STATE_CONNECTED) ||
-	    (info->connected == BLKIF_STATE_SUSPENDED) )
+	switch (info->connected) {
+	case BLKIF_STATE_CONNECTED:
+		/*
+		 * Potentially, the back-end may be signalling
+		 * a capacity change; update the capacity.
+		 */
+		err = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
+				   "sectors", "%Lu", &sectors);
+		if (XENBUS_EXIST_ERR(err))
+			return;
+		printk(KERN_INFO "Setting capacity to %Lu\n",
+		       sectors);
+		set_capacity(info->gd, sectors);
+
+		/* fall through */
+	case BLKIF_STATE_SUSPENDED:
 		return;
+	}
 
 	dev_dbg(&info->xbdev->dev, "%s:%s.\n",
 		__func__, info->xbdev->otherend);