queue-4.14/mm-gup-fix-gup_pmd_range-for-dax.patch

   1 From a5f7bbe4a8a35ccf65738311c1eea15c7dd64fe2 Mon Sep 17 00:00:00 2001
   2 From: Yu Zhao <yuzhao@google.com>
   3 Date: Tue, 12 Feb 2019 15:35:58 -0800
   4 Subject: mm/gup: fix gup_pmd_range() for dax
   5
   6 [ Upstream commit 414fd080d125408cb15d04ff4907e1dd8145c8c7 ]
   7
   8 For dax pmd, pmd_trans_huge() returns false but pmd_huge() returns true
   9 on x86.  So the function works as long as hugetlb is configured.
  10 However, dax doesn't depend on hugetlb.
  11
  12 Link: http://lkml.kernel.org/r/20190111034033.601-1-yuzhao@google.com
  13 Signed-off-by: Yu Zhao <yuzhao@google.com>
  14 Reviewed-by: Jan Kara <jack@suse.cz>
  15 Cc: Dan Williams <dan.j.williams@intel.com>
  16 Cc: Huang Ying <ying.huang@intel.com>
  17 Cc: Matthew Wilcox <willy@infradead.org>
  18 Cc: Keith Busch <keith.busch@intel.com>
  19 Cc: "Michael S . Tsirkin" <mst@redhat.com>
  20 Cc: John Hubbard <jhubbard@nvidia.com>
  21 Cc: Wei Yang <richard.weiyang@gmail.com>
  22 Cc: Mike Rapoport <rppt@linux.ibm.com>
  23 Cc: Andrea Arcangeli <aarcange@redhat.com>
  24 Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
  25 Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
  26 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
  27 Signed-off-by: Sasha Levin <sashal@kernel.org>
  28 ---
  29  mm/gup.c | 3 ++-
  30  1 file changed, 2 insertions(+), 1 deletion(-)
  31
  32 diff --git a/mm/gup.c b/mm/gup.c
  33 index 4cc8a6ff0f56..7c0e5b1bbcd4 100644
  34 --- a/mm/gup.c
  35 +++ b/mm/gup.c
  36 @@ -1643,7 +1643,8 @@ static int gup_pmd_range(pud_t pud, unsigned long addr, unsigned long end,
  37                 if (!pmd_present(pmd))
  38                         return 0;
  39
  40 -               if (unlikely(pmd_trans_huge(pmd) || pmd_huge(pmd))) {
  41 +               if (unlikely(pmd_trans_huge(pmd) || pmd_huge(pmd) ||
  42 +                            pmd_devmap(pmd))) {
  43                         /*
  44                          * NUMA hinting faults need to be handled in the GUP
  45                          * slowpath for accounting purposes and so that they
  46 --
  47 2.19.1
  48