From: t_jeang <devnull@localhost>
Date: Tue, 6 Jan 2009 12:06:01 +0000 (+0000)
Subject: Close block devices when the pv drivers take over and flush the buffer cache.
X-Git-Tag: CA-15999-blkback-pause-unpause
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=9067dfe9d2f8632940d387b175803d5f6dbe075c;p=xenclient%2Fkernel.git

Close block devices when the pv drivers take over and flush the buffer cache.
- close and free the block devices in qemu when we switch to pv drivers in
  the guest
- use BLKFLSBUF to flush the buffer cache, both in qemu and in blkback
---

diff --git a/drivers/xen/blkback/vbd.c b/drivers/xen/blkback/vbd.c
index 8729176f..8aa6b672 100644
--- a/drivers/xen/blkback/vbd.c
+++ b/drivers/xen/blkback/vbd.c
@@ -31,6 +31,8 @@
  */
 
 #include "common.h"
+#include <linux/fs.h>
+#include <linux/buffer_head.h>
 
 #define vbd_sz(_v)   ((_v)->bdev->bd_part ?				\
 	(_v)->bdev->bd_part->nr_sects : (_v)->bdev->bd_disk->capacity)
@@ -93,6 +95,13 @@ int vbd_create(blkif_t *blkif, blkif_vdev_t handle, unsigned major,
 
 void vbd_free(struct vbd *vbd)
 {
+	if (vbd->bdev) {
+		/* BLKFLSBUF */
+		lock_kernel();
+		fsync_bdev(vbd->bdev);
+		invalidate_bdev(vbd->bdev, 0);
+		unlock_kernel();
+	}
 	if (vbd->bdev)
 		blkdev_put(vbd->bdev);
 	vbd->bdev = NULL;