md/bitmap: remove unused fields from struct bitmap

Get rid of ->syncchunk and ->counter_bits since they're never used.

Also discard COUNTER_BYTE_RATIO which is unused.
Signed-off-by: NNamhyung Kim <namhyung@gmail.com>
Signed-off-by: NNeilBrown <neilb@suse.de>

drivers/md/bitmap.c

@@ -1837,9 +1837,6 @@ int bitmap_create(mddev_t *mddev)
 	bitmap->chunks = chunks;
 	bitmap->pages = pages;
 	bitmap->missing_pages = pages;
-	bitmap->counter_bits = COUNTER_BITS;
-
-	bitmap->syncchunk = ~0UL;
 
 #ifdef INJECT_FATAL_FAULT_1
 	bitmap->bp = NULL;

drivers/md/bitmap.h

@@ -85,7 +85,6 @@
 typedef __u16 bitmap_counter_t;
 #define COUNTER_BITS 16
 #define COUNTER_BIT_SHIFT 4
-#define COUNTER_BYTE_RATIO (COUNTER_BITS / 8)
 #define COUNTER_BYTE_SHIFT (COUNTER_BIT_SHIFT - 3)
 
 #define NEEDED_MASK ((bitmap_counter_t) (1 << (COUNTER_BITS - 1)))
@@ -196,19 +195,10 @@ struct bitmap {
 
 	mddev_t *mddev; /* the md device that the bitmap is for */
 
-	int counter_bits; /* how many bits per block counter */
-
 	/* bitmap chunksize -- how much data does each bit represent? */
 	unsigned long chunkshift; /* chunksize = 2^chunkshift (for bitops) */
 	unsigned long chunks; /* total number of data chunks for the array */
 
-	/* We hold a count on the chunk currently being synced, and drop
-	 * it when the last block is started.  If the resync is aborted
-	 * midway, we need to be able to drop that count, so we remember
-	 * the counted chunk..
-	 */
-	unsigned long syncchunk;
-
 	__u64	events_cleared;
 	int need_sync;