mm/hugetlb: add migration/hwpoisoned entry check in hugetlb_change_protection

[linux-2.6-block.git] / mm / hugetlb.c

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 385c3a1aced78f7dcd83f97597100816049bd9bc..c2970e7eb5271bab137692e3f53989313c9d34b1 100644 (file)
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -3384,7 +3384,26 @@ unsigned long hugetlb_change_protection(struct vm_area_struct *vma,
                        spin_unlock(ptl);
                        continue;
                }
-               if (!huge_pte_none(huge_ptep_get(ptep))) {
+               pte = huge_ptep_get(ptep);
+               if (unlikely(is_hugetlb_entry_hwpoisoned(pte))) {
+                       spin_unlock(ptl);
+                       continue;
+               }
+               if (unlikely(is_hugetlb_entry_migration(pte))) {
+                       swp_entry_t entry = pte_to_swp_entry(pte);
+
+                       if (is_write_migration_entry(entry)) {
+                               pte_t newpte;
+
+                               make_migration_entry_read(&entry);
+                               newpte = swp_entry_to_pte(entry);
+                               set_huge_pte_at(mm, address, ptep, newpte);
+                               pages++;
+                       }
+                       spin_unlock(ptl);
+                       continue;
+               }
+               if (!huge_pte_none(pte)) {
                        pte = huge_ptep_get_and_clear(mm, address, ptep);
                        pte = pte_mkhuge(huge_pte_modify(pte, newprot));
                        pte = arch_make_huge_pte(pte, vma, NULL, 0);