swap_info: swap count continuations

[safe/jmp/linux-2.6] / mm / memory.c

diff --git a/mm/memory.c b/mm/memory.c
index 6ab19dd..543c446 100644 (file)
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -572,7 +572,7 @@ out:
  * covered by this vma.
  */
 
-static inline void
+static inline unsigned long
 copy_one_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm,
                pte_t *dst_pte, pte_t *src_pte, struct vm_area_struct *vma,
                unsigned long addr, int *rss)
@@ -586,7 +586,9 @@ copy_one_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm,
                if (!pte_file(pte)) {
                        swp_entry_t entry = pte_to_swp_entry(pte);
 
-                       swap_duplicate(entry);
+                       if (swap_duplicate(entry) < 0)
+                               return entry.val;
+
                        /* make sure dst_mm is on swapoff's mmlist. */
                        if (unlikely(list_empty(&dst_mm->mmlist))) {
                                spin_lock(&mmlist_lock);
@@ -635,6 +637,7 @@ copy_one_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm,
 
 out_set_pte:
        set_pte_at(dst_mm, addr, dst_pte, pte);
+       return 0;
 }
 
 static int copy_pte_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
@@ -646,6 +649,7 @@ static int copy_pte_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
        spinlock_t *src_ptl, *dst_ptl;
        int progress = 0;
        int rss[2];
+       swp_entry_t entry = (swp_entry_t){0};
 
 again:
        rss[1] = rss[0] = 0;
@@ -674,7 +678,10 @@ again:
                        progress++;
                        continue;
                }
-               copy_one_pte(dst_mm, src_mm, dst_pte, src_pte, vma, addr, rss);
+               entry.val = copy_one_pte(dst_mm, src_mm, dst_pte, src_pte,
+                                                       vma, addr, rss);
+               if (entry.val)
+                       break;
                progress += 8;
        } while (dst_pte++, src_pte++, addr += PAGE_SIZE, addr != end);
 
@@ -684,6 +691,12 @@ again:
        add_mm_rss(dst_mm, rss[0], rss[1]);
        pte_unmap_unlock(orig_dst_pte, dst_ptl);
        cond_resched();
+
+       if (entry.val) {
+               if (add_swap_count_continuation(entry, GFP_KERNEL) < 0)
+                       return -ENOMEM;
+               progress = 0;
+       }
        if (addr != end)
                goto again;
        return 0;