queue-4.19/brd-re-enable-__gfp_highmem-in-brd_insert_page.patch

   1 From f6b50160a06d4a0d6a3999ab0c5aec4f52dba248 Mon Sep 17 00:00:00 2001
   2 From: Hou Tao <houtao1@huawei.com>
   3 Date: Mon, 22 Apr 2019 21:23:21 +0800
   4 Subject: brd: re-enable __GFP_HIGHMEM in brd_insert_page()
   5
   6 From: Hou Tao <houtao1@huawei.com>
   7
   8 commit f6b50160a06d4a0d6a3999ab0c5aec4f52dba248 upstream.
   9
  10 __GFP_HIGHMEM is disabled if dax is enabled on brd, however
  11 dax support for brd has been removed since commit (7a862fbbdec6
  12 "brd: remove dax support"), so restore __GFP_HIGHMEM in
  13 brd_insert_page().
  14
  15 Also remove the no longer applicable comments about DAX and highmem.
  16
  17 Cc: stable@vger.kernel.org
  18 Fixes: 7a862fbbdec6 ("brd: remove dax support")
  19 Signed-off-by: Hou Tao <houtao1@huawei.com>
  20 Signed-off-by: Jens Axboe <axboe@kernel.dk>
  21 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  22
  23 ---
  24  drivers/block/brd.c |    7 +------
  25  1 file changed, 1 insertion(+), 6 deletions(-)
  26
  27 --- a/drivers/block/brd.c
  28 +++ b/drivers/block/brd.c
  29 @@ -96,13 +96,8 @@ static struct page *brd_insert_page(stru
  30         /*
  31          * Must use NOIO because we don't want to recurse back into the
  32          * block or filesystem layers from page reclaim.
  33 -        *
  34 -        * Cannot support DAX and highmem, because our ->direct_access
  35 -        * routine for DAX must return memory that is always addressable.
  36 -        * If DAX was reworked to use pfns and kmap throughout, this
  37 -        * restriction might be able to be lifted.
  38          */
  39 -       gfp_flags = GFP_NOIO | __GFP_ZERO;
  40 +       gfp_flags = GFP_NOIO | __GFP_ZERO | __GFP_HIGHMEM;
  41         page = alloc_page(gfp_flags);
  42         if (!page)
  43                 return NULL;