Index: uspace/lib/ext4/libext4_filesystem.c
===================================================================
--- uspace/lib/ext4/libext4_filesystem.c	(revision d76973c2bfdc27bfc941ad522218564772836ded)
+++ uspace/lib/ext4/libext4_filesystem.c	(revision 60c409cdbe62c51e3a0b05c6d20abcdf673b9a77)
@@ -261,6 +261,7 @@
 {
 	uint32_t blocks_per_group = ext4_superblock_get_blocks_per_group(sb);
-
-	return b / blocks_per_group;
+	uint32_t first_block = ext4_superblock_get_first_data_block(sb);
+
+	return (b - first_block) / blocks_per_group;
 }