Fix VM_FAULT flags conversion for hugetlb

It seems a simple mistake was made when converting follow_hugetlb_page()
over to the VM_FAULT flags bitmasks (in "mm: fault feedback #2", commit
83c54070ee1a2d05c89793884bea1a03f2851ed4).

By using the wrong bitmask, hugetlb_fault() failures are not being
recognized.  This results in an infinite loop whenever follow_hugetlb_page
is involved in a failed fault.

Signed-off-by: Adam Litke <agl@us.ibm.com>
Acked-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index d7ca59d..de4cf45 100644 (file)
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -643,7 +643,7 @@ int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
                        spin_unlock(&mm->page_table_lock);
                        ret = hugetlb_fault(mm, vma, vaddr, 0);
                        spin_lock(&mm->page_table_lock);
-                       if (!(ret & VM_FAULT_MAJOR))
+                       if (!(ret & VM_FAULT_ERROR))
                                continue;
 
                        remainder = 0;