When we're effectively deflating the balloon while migrating a page
because inflating the new page failed, we're not adjusting
BALLOON_DEFLATE.

Let's do that. This is a preparation for factoring out this handling to
the core code, making it work in a similar way first.

As this (deflating while migrating because of inflation error) is a
corner case that I don't really expect to happen in practice
and the stats are not that crucial, this likely doesn't classify as a fix.

Reviewed-by: SeongJae Park <sj@kernel.org>
Reviewed-by: Lorenzo Stoakes <redacted>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David Hildenbrand (Red Hat) <david@kernel.org>
---
 drivers/misc/vmw_balloon.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/misc/vmw_balloon.c b/drivers/misc/vmw_balloon.c
index cc1d18b3df5ca..2cc34c4968fac 100644
--- a/drivers/misc/vmw_balloon.c
+++ b/drivers/misc/vmw_balloon.c

@@ -1818,6 +1818,8 @@ static int vmballoon_migratepage(struct balloon_dev_info *b_dev_info,
 	if (status == VMW_BALLOON_SUCCESS) {
 		balloon_page_insert(&b->b_dev_info, newpage);
 		__count_vm_event(BALLOON_MIGRATE);
+	} else {
+		__count_vm_event(BALLOON_DEFLATE);
 	}
 
 	/*

-- 
2.52.0