superblock         10 kernel/defs.h  struct superblock;
superblock         68 kernel/defs.h  void            initlog(int, struct superblock*);
superblock         27 kernel/fs.c    struct superblock sb; 
superblock         31 kernel/fs.c    readsb(int dev, struct superblock *sb)
superblock         55 kernel/log.c   initlog(int dev, struct superblock *sb)
superblock         30 mkfs/mkfs.c    struct superblock sb;