mm: mbind: add hugepage migration code to mbind()

Extend do_mbind() to handle vma with VM_HUGETLB set.  We will be able to
migrate hugepage with mbind(2) after applying the enablement patch which
comes later in this series.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Acked-by: Hillf Danton <dhillf@gmail.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Rik van Riel <riel@redhat.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 14 insertions, 0 deletions

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index e51723866fb1..d37b3b95c439 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1207,6 +1207,20 @@ static struct page *alloc_huge_page(struct vm_area_struct *vma,
         return page;
 }
 
+/*
+ * alloc_huge_page()'s wrapper which simply returns the page if allocation
+ * succeeds, otherwise NULL. This function is called from new_vma_page(),
+ * where no ERR_VALUE is expected to be returned.
+ */
+struct page *alloc_huge_page_noerr(struct vm_area_struct *vma,
+                                unsigned long addr, int avoid_reserve)
+{
+        struct page *page = alloc_huge_page(vma, addr, avoid_reserve);
+        if (IS_ERR(page))
+                page = NULL;
+        return page;
+}
+
 int __weak alloc_bootmem_huge_page(struct hstate *h)
 {
         struct huge_bootmem_page *m;