lib/raid6: drop RAID6_USE_EMPTY_ZERO_PAGE

RAID6_USE_EMPTY_ZERO_PAGE is unused and hardcoded to 0, so let's drop it.
Signed-off-by: NGiulio Benetti <giulio.benetti@benettiengineering.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NSong Liu <song@kernel.org>

include/linux/raid/pq.h

@@ -10,17 +10,9 @@
 
 #ifdef __KERNEL__
 
-/* Set to 1 to use kernel-wide empty_zero_page */
-#define RAID6_USE_EMPTY_ZERO_PAGE 0
 #include <linux/blkdev.h>
 
-/* We need a pre-zeroed page... if we don't want to use the kernel-provided
-   one define it here */
-#if RAID6_USE_EMPTY_ZERO_PAGE
-# define raid6_empty_zero_page empty_zero_page
-#else
 extern const char raid6_empty_zero_page[PAGE_SIZE];
-#endif
 
 #else /* ! __KERNEL__ */
 /* Used for testing in user space */

lib/raid6/algos.c

@@ -18,12 +18,10 @@
 #else
 #include <linux/module.h>
 #include <linux/gfp.h>
-#if !RAID6_USE_EMPTY_ZERO_PAGE
 /* In .bss so it's zeroed */
 const char raid6_empty_zero_page[PAGE_SIZE] __attribute__((aligned(256)));
 EXPORT_SYMBOL(raid6_empty_zero_page);
 #endif
-#endif
 
 struct raid6_calls raid6_call;
 EXPORT_SYMBOL_GPL(raid6_call);