[PATCH 5.1 035/122] brd: re-enable __GFP_HIGHMEM in brd_insert_page()

Greg Kroah-Hartman
2019-05-23T19:27:11Z

From: Hou Tao <houtao1@huawei.com>

commit f6b50160a06d4a0d6a3999ab0c5aec4f52dba248 upstream.

__GFP_HIGHMEM is disabled if dax is enabled on brd, however
dax support for brd has been removed since commit (7a862fbbdec6
"brd: remove dax support"), so restore __GFP_HIGHMEM in
brd_insert_page().

Also remove the no longer applicable comments about DAX and highmem.

Cc: stable@vger.kernel.org
Fixes: 7a862fbbdec6 ("brd: remove dax support")
Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/block/brd.c | 7 +------
1 file changed, 1 insertion(+), 6 deletions(-)

--- a/drivers/block/brd.c
+++ b/drivers/block/brd.c
@@ -96,13 +96,8 @@ static struct page *brd_insert_page(stru
/*
* Must use NOIO because we don't want to recurse back into the
* block or filesystem layers from page reclaim.
- *
- * Cannot support DAX and highmem, because our ->direct_access
- * routine for DAX must return memory that is always addressable.
- * If DAX was reworked to use pfns and kmap throughout, this
- * restriction might be able to be lifted.
*/
- gfp_flags = GFP_NOIO | __GFP_ZERO;
+ gfp_flags = GFP_NOIO | __GFP_ZERO | __GFP_HIGHMEM;
page = alloc_page(gfp_flags);
if (!page)
return NULL;