hv_balloon: mark inflated pages PG_offline

Mark inflated and never onlined pages PG_offline, to tell the world that
the content is stale and should not be dumped.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: David Hildenbrand <[email protected]>
Acked-by: Pankaj gupta <[email protected]>
Cc: "K. Y. Srinivasan" <[email protected]>
Cc: Haiyang Zhang <[email protected]>
Cc: Stephen Hemminger <[email protected]>
Cc: Kairui Song <[email protected]>
Cc: Vitaly Kuznetsov <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: "Michael S. Tsirkin" <[email protected]>
Cc: Alexander Duyck <[email protected]>
Cc: Alexey Dobriyan <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Baoquan He <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Boris Ostrovsky <[email protected]>
Cc: Christian Hansen <[email protected]>
Cc: Dave Young <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Juergen Gross <[email protected]>
Cc: Julien Freche <[email protected]>
Cc: Kazuhito Hagio <[email protected]>
Cc: "Kirill A. Shutemov" <[email protected]>
Cc: Konstantin Khlebnikov <[email protected]>
Cc: Len Brown <[email protected]>
Cc: Lianbo Jiang <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Miles Chen <[email protected]>
Cc: Nadav Amit <[email protected]>
Cc: Naoya Horiguchi <[email protected]>
Cc: Omar Sandoval <[email protected]>
Cc: Pavel Machek <[email protected]>
Cc: Pavel Tatashin <[email protected]>
Cc: Rafael J. Wysocki <[email protected]>
Cc: "Rafael J. Wysocki" <[email protected]>
Cc: Stefano Stabellini <[email protected]>
Cc: Stephen Rothwell <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Xavier Deguillard <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

1 files changed, 12 insertions, 2 deletions

diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c
index a50b7624b2a3..dd475f3bcc8a 100644
--- a/drivers/hv/hv_balloon.c
+++ b/drivers/hv/hv_balloon.c
@@ -681,8 +681,13 @@ static struct notifier_block hv_memory_nb = {
 /* Check if the particular page is backed and can be onlined and online it. */
 static void hv_page_online_one(struct hv_hotadd_state *has, struct page *pg)
 {
-	if (!has_pfn_is_backed(has, page_to_pfn(pg)))
+	if (!has_pfn_is_backed(has, page_to_pfn(pg))) {
+		if (!PageOffline(pg))
+			__SetPageOffline(pg);
 		return;
+	}
+	if (PageOffline(pg))
+		__ClearPageOffline(pg);
 
 	/* This frame is currently backed; online the page. */
 	__online_page_set_limits(pg);
@@ -1202,6 +1207,7 @@ static void free_balloon_pages(struct hv_dynmem_device *dm,
 
 	for (i = 0; i < num_pages; i++) {
 		pg = pfn_to_page(i + start_frame);
+		__ClearPageOffline(pg);
 		__free_page(pg);
 		dm->num_pages_ballooned--;
 	}
@@ -1214,7 +1220,7 @@ static unsigned int alloc_balloon_pages(struct hv_dynmem_device *dm,
 					struct dm_balloon_response *bl_resp,
 					int alloc_unit)
 {
-	unsigned int i = 0;
+	unsigned int i, j;
 	struct page *pg;
 
 	if (num_pages < alloc_unit)
@@ -1246,6 +1252,10 @@ static unsigned int alloc_balloon_pages(struct hv_dynmem_device *dm,
 		if (alloc_unit != 1)
 			split_page(pg, get_order(alloc_unit << PAGE_SHIFT));
 
+		/* mark all pages offline */
+		for (j = 0; j < (1 << get_order(alloc_unit << PAGE_SHIFT)); j++)
+			__SetPageOffline(pg + j);
+
 		bl_resp->range_count++;
 		bl_resp->range_array[i].finfo.start_page =
 			page_to_pfn(pg);