diff --git a/lib/ext2fs/alloc_sb.c b/lib/ext2fs/alloc_sb.c
index 09786a7..2e32389 100644
--- a/lib/ext2fs/alloc_sb.c
+++ b/lib/ext2fs/alloc_sb.c
@@ -74,15 +74,7 @@ int ext2fs_reserve_super_and_bgd(ext2_filsys fs,
 	if (new_desc_blk)
 		ext2fs_mark_block_bitmap2(bmap, new_desc_blk);
 
-	if (group == fs->group_desc_count-1) {
-		num_blocks = (ext2fs_blocks_count(fs->super) -
-			     fs->super->s_first_data_block) %
-			fs->super->s_blocks_per_group;
-		if (!num_blocks)
-			num_blocks = fs->super->s_blocks_per_group;
-	} else
-		num_blocks = fs->super->s_blocks_per_group;
-
+	num_blocks = ext2fs_group_blocks_count(fs, group);
 	num_blocks -= 2 + fs->inode_blocks_per_group + used_blks;
 
 	return num_blocks  ;
diff --git a/lib/ext2fs/blknum.c b/lib/ext2fs/blknum.c
index b3e6dca..f1bbe9b 100644
--- a/lib/ext2fs/blknum.c
+++ b/lib/ext2fs/blknum.c
@@ -43,6 +43,25 @@ blk64_t ext2fs_group_last_block2(ext2_filsys fs, dgrp_t group)
 }
 
 /*
+ * Return the number of blocks in a group
+ */
+int ext2fs_group_blocks_count(ext2_filsys fs, dgrp_t group)
+{
+	int num_blocks;
+
+	if (group == fs->group_desc_count-1) {
+		num_blocks = (ext2fs_blocks_count(fs->super) -
+				fs->super->s_first_data_block) %
+			      fs->super->s_blocks_per_group;
+		if (!num_blocks)
+			num_blocks = fs->super->s_blocks_per_group;
+	} else
+		num_blocks = fs->super->s_blocks_per_group;
+
+	return num_blocks;
+}
+
+/*
  * Return the inode data block count
  */
 blk64_t ext2fs_inode_data_blocks2(ext2_filsys fs,
diff --git a/lib/ext2fs/closefs.c b/lib/ext2fs/closefs.c
index 952f496..51ef63c 100644
--- a/lib/ext2fs/closefs.c
+++ b/lib/ext2fs/closefs.c
@@ -152,14 +152,7 @@ int ext2fs_super_and_bgd_loc(ext2_filsys fs,
 					&ret_new_desc_blk2,
 					&ret_used_blks);
 
-	if (group == fs->group_desc_count-1) {
-		numblocks = (ext2fs_blocks_count(fs->super) -
-			     (blk64_t) fs->super->s_first_data_block) %
-			(blk64_t) fs->super->s_blocks_per_group;
-		if (!numblocks)
-			numblocks = fs->super->s_blocks_per_group;
-	} else
-		numblocks = fs->super->s_blocks_per_group;
+	numblocks = ext2fs_group_blocks_count(fs, group);
 
 	if (ret_super_blk)
 		*ret_super_blk = (blk_t)ret_super_blk2;
diff --git a/lib/ext2fs/ext2fs.h b/lib/ext2fs/ext2fs.h
index dc83fb0..60a903a 100644
--- a/lib/ext2fs/ext2fs.h
+++ b/lib/ext2fs/ext2fs.h
@@ -757,6 +757,7 @@ extern errcode_t ext2fs_get_block_bitmap_range2(ext2fs_block_bitmap bmap,
 extern dgrp_t ext2fs_group_of_blk2(ext2_filsys fs, blk64_t);
 extern blk64_t ext2fs_group_first_block2(ext2_filsys fs, dgrp_t group);
 extern blk64_t ext2fs_group_last_block2(ext2_filsys fs, dgrp_t group);
+extern int ext2fs_group_blocks_count(ext2_filsys fs, dgrp_t group);
 extern blk64_t ext2fs_inode_data_blocks2(ext2_filsys fs,
 					 struct ext2_inode *inode);
 extern blk64_t ext2fs_inode_i_blocks(ext2_filsys fs,
diff --git a/resize/online.c b/resize/online.c
index 1d8d4ec..c2b98c6 100644
--- a/resize/online.c
+++ b/resize/online.c
@@ -135,12 +135,7 @@ errcode_t online_resize_fs(ext2_filsys fs, const char *mtpt,
 		input.block_bitmap = ext2fs_block_bitmap_loc(new_fs, i);
 		input.inode_bitmap = ext2fs_inode_bitmap_loc(new_fs, i);
 		input.inode_table = ext2fs_inode_table_loc(new_fs, i);
-		input.blocks_count = sb->s_blocks_per_group;
-		if (i == new_fs->group_desc_count-1) {
-			input.blocks_count = ext2fs_blocks_count(new_fs->super) -
-				sb->s_first_data_block -
-				(i * sb->s_blocks_per_group);
-		}
+		input.blocks_count = ext2fs_group_blocks_count(new_fs, i);
 		input.reserved_blocks = (blk_t) (percent * input.blocks_count
 						 / 100.0);
 
diff --git a/resize/resize2fs.c b/resize/resize2fs.c
index 45ea5f4..a8e7d51 100644
--- a/resize/resize2fs.c
+++ b/resize/resize2fs.c
@@ -499,18 +499,8 @@ retry:
 		ext2fs_bg_flags_zap(fs, i);
 		if (csum_flag)
 			ext2fs_bg_flags_set(fs, i, EXT2_BG_INODE_UNINIT | EXT2_BG_INODE_ZEROED);
-		if (i == fs->group_desc_count-1) {
-			numblocks = (ext2fs_blocks_count(fs->super) -
-				     fs->super->s_first_data_block) %
-					     fs->super->s_blocks_per_group;
-			if (!numblocks)
-				numblocks = fs->super->s_blocks_per_group;
-		} else {
-			numblocks = fs->super->s_blocks_per_group;
-			if (csum_flag)
-				ext2fs_bg_flags_set(fs, i,
-						    EXT2_BG_BLOCK_UNINIT);
-		}
+
+		numblocks = ext2fs_group_blocks_count(fs, i);
 
 		has_super = ext2fs_bg_has_super(fs, i);
 		if (has_super) {
