diff --git a/drivers/md/md-bitmap.c b/drivers/md/md-bitmap.c
index b28302836..91bc764a8 100755
--- a/drivers/md/md-bitmap.c
+++ b/drivers/md/md-bitmap.c
@@ -1355,7 +1355,7 @@ __acquires(bitmap->lock)
 	sector_t chunk = offset >> bitmap->chunkshift;
 	unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
 	unsigned long pageoff = (chunk & PAGE_COUNTER_MASK) << COUNTER_BYTE_SHIFT;
-	sector_t csize;
+	sector_t csize = ((sector_t)1) << bitmap->chunkshift;
 	int err;
 
 	if (page >= bitmap->pages) {
@@ -1364,6 +1364,7 @@ __acquires(bitmap->lock)
 		 * End-of-device while looking for a whole page or
 		 * user set a huge number to sysfs bitmap_set_bits.
 		 */
+		*blocks = csize - (offset & (csize - 1));
 		return NULL;
 	}
 	err = md_bitmap_checkpage(bitmap, page, create, 0);
@@ -1372,8 +1373,7 @@ __acquires(bitmap->lock)
 	    bitmap->bp[page].map == NULL)
 		csize = ((sector_t)1) << (bitmap->chunkshift +
 					  PAGE_COUNTER_SHIFT);
-	else
-		csize = ((sector_t)1) << bitmap->chunkshift;
+
 	*blocks = csize - (offset & (csize - 1));
 
 	if (err < 0)