Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc

[cascardo/linux.git] / arch / powerpc / mm / hugetlbpage.c

diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index 48b65be..5964371 100644 (file)
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -614,7 +614,7 @@ static noinline int gup_hugepte(pte_t *ptep, unsigned long sz, unsigned long add
 {
        unsigned long mask;
        unsigned long pte_end;
-       struct page *head, *page;
+       struct page *head, *page, *tail;
        pte_t pte;
        int refs;
 
@@ -637,6 +637,7 @@ static noinline int gup_hugepte(pte_t *ptep, unsigned long sz, unsigned long add
        head = pte_page(pte);
 
        page = head + ((addr & (sz-1)) >> PAGE_SHIFT);
+       tail = page;
        do {
                VM_BUG_ON(compound_head(page) != head);
                pages[*nr] = page;
@@ -652,10 +653,20 @@ static noinline int gup_hugepte(pte_t *ptep, unsigned long sz, unsigned long add
 
        if (unlikely(pte_val(pte) != pte_val(*ptep))) {
                /* Could be optimized better */
-               while (*nr) {
-                       put_page(page);
-                       (*nr)--;
-               }
+               *nr -= refs;
+               while (refs--)
+                       put_page(head);
+               return 0;
+       }
+
+       /*
+        * Any tail page need their mapcount reference taken before we
+        * return.
+        */
+       while (refs--) {
+               if (PageTail(tail))
+                       get_huge_page_tail(tail);
+               tail++;
        }
 
        return 1;