[RFC PATCH v2 07/12] fs/btrfs/extent_io: update usage of address zone modifiers

[Huaisheng HS1 Ye]

Use __GFP_ZONE_MASK to replace (__GFP_DMA32 | __GFP_HIGHMEM).

In function alloc_extent_state, it is obvious that __GFP_DMA is not 
the expecting zone type.

___GFP_DMA, ___GFP_HIGHMEM and ___GFP_DMA32 have been deleted from GFP 
bitmasks, the bottom three bits of GFP mask is reserved for storing
encoded zone number.
__GFP_DMA, __GFP_HIGHMEM and __GFP_DMA32 should not be operated with
each others by OR. 

Signed-off-by: Huaisheng Ye <yehs1@xxxxxxxxxx>
Cc: Chris Mason <clm@xxxxxx>
Cc: Josef Bacik <jbacik@xxxxxx>
Cc: David Sterba <dsterba@xxxxxxxx>
---
 fs/btrfs/extent_io.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index dfeb74a..6653e9a 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -220,7 +220,7 @@ static struct extent_state *alloc_extent_state(gfp_t mask)
         * The given mask might be not appropriate for the slab allocator,
         * drop the unsupported bits
         */
-       mask &= ~(__GFP_DMA32|__GFP_HIGHMEM);
+       mask &= ~__GFP_ZONE_MASK;
        state = kmem_cache_alloc(extent_state_cache, mask);
        if (!state)
                return state;
-- 
1.8.3.1