diff --git a/[refs] b/[refs]
index 876da2ba0927..3278c591f072 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 1031be7a5fafd3a858dfaabb74d98f9ca20744a8
+refs/heads/master: f49d5e62d9352d33b30c9befbaf0fd9c88265ec1
diff --git a/trunk/drivers/md/bitmap.c b/trunk/drivers/md/bitmap.c
index 5432d07c074d..11108165e264 100644
--- a/trunk/drivers/md/bitmap.c
+++ b/trunk/drivers/md/bitmap.c
@@ -479,9 +479,12 @@ static int bitmap_read_sb(struct bitmap *bitmap)
 	int err = -EINVAL;
 
 	/* page 0 is the superblock, read it... */
-	if (bitmap->file)
-		bitmap->sb_page = read_page(bitmap->file, 0, bitmap, PAGE_SIZE);
-	else {
+	if (bitmap->file) {
+		loff_t isize = i_size_read(bitmap->file->f_mapping->host);
+		int bytes = isize > PAGE_SIZE ? PAGE_SIZE : isize;
+
+		bitmap->sb_page = read_page(bitmap->file, 0, bitmap, bytes);
+	} else {
 		bitmap->sb_page = read_sb_page(bitmap->mddev, bitmap->offset, 0);
 	}
 	if (IS_ERR(bitmap->sb_page)) {
@@ -877,7 +880,8 @@ static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
 			int count;
 			/* unmap the old page, we're done with it */
 			if (index == num_pages-1)
-				count = bytes - index * PAGE_SIZE;
+				count = bytes + sizeof(bitmap_super_t)
+					- index * PAGE_SIZE;
 			else
 				count = PAGE_SIZE;
 			if (index == 0) {