1 files changed, 50 insertions, 4 deletions

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 421aee99b84a..6058b53dcb89 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -354,11 +354,26 @@ static int vma_has_reserves(struct vm_area_struct *vma)
         return 0;
 }
 
+static void clear_gigantic_page(struct page *page,
+                        unsigned long addr, unsigned long sz)
+{
+        int i;
+        struct page *p = page;
+
+        might_sleep();
+        for (i = 0; i < sz/PAGE_SIZE; i++, p = mem_map_next(p, page, i)) {
+                cond_resched();
+                clear_user_highpage(p, addr + i * PAGE_SIZE);
+        }
+}
 static void clear_huge_page(struct page *page,
                         unsigned long addr, unsigned long sz)
 {
         int i;
 
+        if (unlikely(sz > MAX_ORDER_NR_PAGES))
+                return clear_gigantic_page(page, addr, sz);
+
         might_sleep();
         for (i = 0; i < sz/PAGE_SIZE; i++) {
                 cond_resched();
@@ -366,12 +381,32 @@ static void clear_huge_page(struct page *page,
         }
 }
 
+static void copy_gigantic_page(struct page *dst, struct page *src,
+                           unsigned long addr, struct vm_area_struct *vma)
+{
+        int i;
+        struct hstate *h = hstate_vma(vma);
+        struct page *dst_base = dst;
+        struct page *src_base = src;
+        might_sleep();
+        for (i = 0; i < pages_per_huge_page(h); ) {
+                cond_resched();
+                copy_user_highpage(dst, src, addr + i*PAGE_SIZE, vma);
+
+                i++;
+                dst = mem_map_next(dst, dst_base, i);
+                src = mem_map_next(src, src_base, i);
+        }
+}
 static void copy_huge_page(struct page *dst, struct page *src,
                            unsigned long addr, struct vm_area_struct *vma)
 {
         int i;
         struct hstate *h = hstate_vma(vma);
 
+        if (unlikely(pages_per_huge_page(h) > MAX_ORDER_NR_PAGES))
+                return copy_gigantic_page(dst, src, addr, vma);
+
         might_sleep();
         for (i = 0; i < pages_per_huge_page(h); i++) {
                 cond_resched();
@@ -456,6 +491,8 @@ static void update_and_free_page(struct hstate *h, struct page *page)
 {
         int i;
 
+        VM_BUG_ON(h->order >= MAX_ORDER);
+
         h->nr_huge_pages--;
         h->nr_huge_pages_node[page_to_nid(page)]--;
         for (i = 0; i < pages_per_huge_page(h); i++) {
@@ -970,6 +1007,14 @@ found:
         return 1;
 }
 
+static void prep_compound_huge_page(struct page *page, int order)
+{
+        if (unlikely(order > (MAX_ORDER - 1)))
+                prep_compound_gigantic_page(page, order);
+        else
+                prep_compound_page(page, order);
+}
+
 /* Put bootmem huge pages into the standard lists after mem_map is up */
 static void __init gather_bootmem_prealloc(void)
 {
@@ -980,7 +1025,7 @@ static void __init gather_bootmem_prealloc(void)
                 struct hstate *h = m->hstate;
                 __ClearPageReserved(page);
                 WARN_ON(page_count(page) != 1);
-                prep_compound_page(page, h->order);
+                prep_compound_huge_page(page, h->order);
                 prep_new_huge_page(h, page, page_to_nid(page));
         }
 }
@@ -1751,6 +1796,7 @@ void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start,
 static int unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma,
                                 struct page *page, unsigned long address)
 {
+        struct hstate *h = hstate_vma(vma);
         struct vm_area_struct *iter_vma;
         struct address_space *mapping;
         struct prio_tree_iter iter;
@@ -1760,7 +1806,7 @@ static int unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma,
          * vm_pgoff is in PAGE_SIZE units, hence the different calculation
          * from page cache lookup which is in HPAGE_SIZE units.
          */
-        address = address & huge_page_mask(hstate_vma(vma));
+        address = address & huge_page_mask(h);
         pgoff = ((address - vma->vm_start) >> PAGE_SHIFT)
                 + (vma->vm_pgoff >> PAGE_SHIFT);
         mapping = (struct address_space *)page_private(page);
@@ -1779,7 +1825,7 @@ static int unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma,
                  */
                 if (!is_vma_resv_set(iter_vma, HPAGE_RESV_OWNER))
                         unmap_hugepage_range(iter_vma,
-                                address, address + HPAGE_SIZE,
+                                address, address + huge_page_size(h),
                                 page);
         }
 
@@ -2130,7 +2176,7 @@ same_page:
                         if (zeropage_ok)
                                 pages[i] = ZERO_PAGE(0);
                         else
-                                pages[i] = page + pfn_offset;
+                                pages[i] = mem_map_offset(page, pfn_offset);
                         get_page(pages[i]);
                 }