mm: mempolicy: skip inaccessible VMAs when setting MPOL_MF_LAZY

PROT_NUMA VMAs are skipped to avoid problems distinguishing between
present, prot_none and special entries.  MPOL_MF_LAZY is not visible from
userspace since commit a720094 ("mm: mempolicy: Hide MPOL_NOOP and
MPOL_MF_LAZY from userspace for now") but it should still skip VMAs the
same way task_numa_work does.

Signed-off-by: Mel Gorman <[email protected]>
Acked-by: Rik van Riel <[email protected]>
Acked-by: Hugh Dickins <[email protected]>
Acked-by: Peter Zijlstra <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

Author: Mel Gorman

mm/mempolicy.c

@@ -681,7 +681,9 @@ queue_pages_range(struct mm_struct *mm, unsigned long start, unsigned long end,
 		}
 
 		if (flags & MPOL_MF_LAZY) {
-			change_prot_numa(vma, start, endvma);
+			/* Similar to task_numa_work, skip inaccessible VMAs */
+			if (vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE))
+				change_prot_numa(vma, start, endvma);
 			goto next;
 		}