+/*
+ * The size of a cylinder group is calculated by CGSIZE. The maximum size
+ * is limited by the fact that cylinder groups are at most one block.
+ * Its size is derived from the size of the maps maintained in the
+ * cylinder group and the (struct cg) size.
+ */
+#define CGSIZE(fs) \
+ /* base cg */ (sizeof(struct cg) + sizeof(long) + \
+ /* blktot size */ (fs)->fs_cpg * sizeof(long) + \
+ /* blks size */ (fs)->fs_cpg * (fs)->fs_nrpos * sizeof(short) + \
+ /* inode map */ howmany((fs)->fs_ipg, NBBY) + \
+ /* block map */ howmany((fs)->fs_cpg * (fs)->fs_spc / NSPF(fs), NBBY) +\
+ /* cluster sum */ (fs)->fs_contigsumsize * sizeof(long) + \
+ /* cluster map */ howmany((fs)->fs_cpg * (fs)->fs_spc / NSPB(fs), NBBY))
+