dbg_dump_csum
dbg_dump_csum("internal old_cstotal", &sb->fs_old_cstotal);
dbg_dump_csum("internal cs", &cgr->cg_cs);
void dbg_dump_csum(const char *, struct csum *);
#define DBG_DUMP_CSUM(F,C,M) dbg_dump_csum((C),(M))