commit 1fa73be6be65028a7543bba8f14474b42e064a1b
author K. Y. Srinivasan <ksrinivasan@novell.com> Thu Mar 11 13:42:26 2010 -0800
committer Jens Axboe <jaxboe@fusionio.com> Sat Aug 07 18:31:27 2010 +0200
tree 1bd0e5a44c99231afefe53e447bddc4b73d091cb
parent 5d7ed20e822ef82117a4d9928b030fa0247b789d

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

diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 60006b7..f47b096 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -930,9 +930,24 @@
 	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);