1 files changed, 1 insertions, 2 deletions

diff --git a/drivers/md/bitmap.h b/drivers/md/bitmap.h
index e196e6a560e8..55ca5aec84e4 100644
--- a/drivers/md/bitmap.h
+++ b/drivers/md/bitmap.h
@@ -103,7 +103,6 @@ typedef __u16 bitmap_counter_t;
 
 /* how many blocks per chunk? (this is variable) */
 #define CHUNK_BLOCK_RATIO(bitmap) ((bitmap)->mddev->bitmap_info.chunksize >> BITMAP_BLOCK_SHIFT)
-#define CHUNK_BLOCK_SHIFT(bitmap) ((bitmap)->chunkshift - BITMAP_BLOCK_SHIFT)
 
 #endif
 
@@ -178,7 +177,7 @@ struct bitmap {
         struct mddev *mddev; /* the md device that the bitmap is for */
 
         /* bitmap chunksize -- how much data does each bit represent? */
-        unsigned long chunkshift; /* chunksize = 2^chunkshift (for bitops) */
+        unsigned long chunkshift; /* chunksize = 2^(chunkshift+9) (for bitops) */
         unsigned long chunks; /* total number of data chunks for the array */
 
         __u64   events_cleared;