mm: save soft-dirty bits on swapped pages

[karo-tx-linux.git] / fs / proc / task_mmu.c

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index dbf61f6174f0f473d3d9a19311a09170f8dab9f3..e2d9bdce5e7ef7b5adb12c623f0a22e95fd10d07 100644 (file)
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -730,8 +730,14 @@ static inline void clear_soft_dirty(struct vm_area_struct *vma,
         * of how soft-dirty works.
         */
        pte_t ptent = *pte;
-       ptent = pte_wrprotect(ptent);
-       ptent = pte_clear_flags(ptent, _PAGE_SOFT_DIRTY);
+
+       if (pte_present(ptent)) {
+               ptent = pte_wrprotect(ptent);
+               ptent = pte_clear_flags(ptent, _PAGE_SOFT_DIRTY);
+       } else if (is_swap_pte(ptent)) {
+               ptent = pte_swp_clear_soft_dirty(ptent);
+       }
+
        set_pte_at(vma->vm_mm, addr, pte, ptent);
 #endif
 }
@@ -752,14 +758,15 @@ static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr,
        pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
        for (; addr != end; pte++, addr += PAGE_SIZE) {
                ptent = *pte;
-               if (!pte_present(ptent))
-                       continue;
 
                if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
                        clear_soft_dirty(vma, addr, pte);
                        continue;
                }
 
+               if (!pte_present(ptent))
+                       continue;
+
                page = vm_normal_page(vma, addr, ptent);
                if (!page)
                        continue;
@@ -930,8 +937,10 @@ static void pte_to_pagemap_entry(pagemap_entry_t *pme, struct pagemapread *pm,
                flags = PM_PRESENT;
                page = vm_normal_page(vma, addr, pte);
        } else if (is_swap_pte(pte)) {
-               swp_entry_t entry = pte_to_swp_entry(pte);
-
+               swp_entry_t entry;
+               if (pte_swp_soft_dirty(pte))
+                       flags2 |= __PM_SOFT_DIRTY;
+               entry = pte_to_swp_entry(pte);
                frame = swp_type(entry) |
                        (swp_offset(entry) << MAX_SWAPFILES_SHIFT);
                flags = PM_SWAP;