Xen balloon: fix totalram_pages counting.

Change totalram_pages when a single page is added/removed to the
ballooned list. This avoid totalram_pages to be set erroneously to
max_pfn at boot.

Signed-off-by: Gianluca Guida <gianluca.guida@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stable Kernel <stable@kernel.org>

1 files changed, 4 insertions, 3 deletions

diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
index d31505b6f7a4..6eb62654410a 100644
--- a/drivers/xen/balloon.c
+++ b/drivers/xen/balloon.c
@@ -136,6 +136,8 @@ static void balloon_append(struct page *page)
                 list_add(&page->lru, &ballooned_pages);
                 balloon_stats.balloon_low++;
         }
+
+        totalram_pages--;
 }
 
 /* balloon_retrieve: rescue a page from the balloon, if it is not empty. */
@@ -156,6 +158,8 @@ static struct page *balloon_retrieve(void)
         else
                 balloon_stats.balloon_low--;
 
+        totalram_pages++;
+
         return page;
 }
 
@@ -260,7 +264,6 @@ static int increase_reservation(unsigned long nr_pages)
         }
 
         balloon_stats.current_pages += nr_pages;
-        totalram_pages = balloon_stats.current_pages;
 
  out:
         spin_unlock_irqrestore(&balloon_lock, flags);
@@ -323,7 +326,6 @@ static int decrease_reservation(unsigned long nr_pages)
         BUG_ON(ret != nr_pages);
 
         balloon_stats.current_pages -= nr_pages;
-        totalram_pages = balloon_stats.current_pages;
 
         spin_unlock_irqrestore(&balloon_lock, flags);
 
@@ -422,7 +424,6 @@ static int __init balloon_init(void)
         pr_info("xen_balloon: Initialising balloon driver.\n");
 
         balloon_stats.current_pages = min(xen_start_info->nr_pages, max_pfn);
-        totalram_pages   = balloon_stats.current_pages;
         balloon_stats.target_pages  = balloon_stats.current_pages;
         balloon_stats.balloon_low   = 0;
         balloon_stats.balloon_high  = 0;