fs/btrfs/extent_io: update usage of zone modifiers

From: Huaisheng Ye <[email protected]>

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.

Use GFP_NORMAL() to clear bottom 3 bits of GFP bitmaks.

---
 fs/btrfs/extent_io.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

index e99b329..f41fc61 100644
@@ -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_NORMAL(mask);
 	state = kmem_cache_alloc(extent_state_cache, mask);
 	if (!state)
 		return state;

1.8.3.1