1 files changed, 17 insertions, 4 deletions

diff --git a/mm/madvise.c b/mm/madvise.c
index ae0ae3ea299a..af3d573b0141 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -22,16 +22,23 @@ static long madvise_behavior(struct vm_area_struct * vma,
         struct mm_struct * mm = vma->vm_mm;
         int error = 0;
         pgoff_t pgoff;
-        int new_flags = vma->vm_flags & ~VM_READHINTMASK;
+        int new_flags = vma->vm_flags;
 
         switch (behavior) {
+        case MADV_NORMAL:
+                new_flags = new_flags & ~VM_RAND_READ & ~VM_SEQ_READ;
+                break;
         case MADV_SEQUENTIAL:
-                new_flags |= VM_SEQ_READ;
+                new_flags = (new_flags & ~VM_RAND_READ) | VM_SEQ_READ;
                 break;
         case MADV_RANDOM:
-                new_flags |= VM_RAND_READ;
+                new_flags = (new_flags & ~VM_SEQ_READ) | VM_RAND_READ;
                 break;
-        default:
+        case MADV_DONTFORK:
+                new_flags |= VM_DONTCOPY;
+                break;
+        case MADV_DOFORK:
+                new_flags &= ~VM_DONTCOPY;
                 break;
         }
 
@@ -177,6 +184,12 @@ madvise_vma(struct vm_area_struct *vma, struct vm_area_struct **prev,
         long error;
 
         switch (behavior) {
+        case MADV_DOFORK:
+                if (vma->vm_flags & VM_IO) {
+                        error = -EINVAL;
+                        break;
+                }
+        case MADV_DONTFORK:
         case MADV_NORMAL:
         case MADV_SEQUENTIAL:
         case MADV_RANDOM: