PM/Hibernate: use pfn_to_online_page()

Let's use pfn_to_online_page() instead of pfn_to_page() when checking
for saveable pages to not save/restore offline memory sections.

Link: http://lkml.kernel.org/r/20181119101616.8901-8-david@redhat.comSigned-off-by: David Hildenbrand <david@redhat.com>
Suggested-by: Michal Hocko <mhocko@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Christian Hansen <chansen3@cisco.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Juergen Gross <jgross@suse.com>
Cc: Julien Freche <jfreche@vmware.com>
Cc: Kairui Song <kasong@redhat.com>
Cc: Kazuhito Hagio <k-hagio@ab.jp.nec.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Lianbo Jiang <lijiang@redhat.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Miles Chen <miles.chen@mediatek.com>
Cc: Nadav Amit <namit@vmware.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Omar Sandoval <osandov@fb.com>
Cc: Pankaj gupta <pagupta@redhat.com>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/power/snapshot.c

@@ -1215,8 +1215,8 @@ static struct page *saveable_highmem_page(struct zone *zone, unsigned long pfn)
 	if (!pfn_valid(pfn))
 		return NULL;
 
-	page = pfn_to_page(pfn);
-	if (page_zone(page) != zone)
+	page = pfn_to_online_page(pfn);
+	if (!page || page_zone(page) != zone)
 		return NULL;
 
 	BUG_ON(!PageHighMem(page));
@@ -1277,8 +1277,8 @@ static struct page *saveable_page(struct zone *zone, unsigned long pfn)
 	if (!pfn_valid(pfn))
 		return NULL;
 
-	page = pfn_to_page(pfn);
-	if (page_zone(page) != zone)
+	page = pfn_to_online_page(pfn);
+	if (!page || page_zone(page) != zone)
 		return NULL;
 
 	BUG_ON(PageHighMem(page));