anchor.diff:          :with file-name := (file-name pathname)
           :for directory :in (rest (pathname-directory pathname))
           :do (block do-files
  -              (do-files (block offset) disk superblock bgdt inode
  +              (do-files (block offset) disk superblock inode
                   (error 'simple-file-error
                          :pathname pathname
                          :format-control "Directory ~A not found. ~S"
  
positive.code:                             :host host
                              :direction direction
                              :file-inode file-inode
                              :block-size (bytes-per-block (file-host-mount-device host) (superblock host))
                              :position file-position
                              :length file-length
                              :abort-action abort-action))
  
negative.code:                             superblock
                              (+ (block-group-descriptor-inode-table bgds)
                                 (floor (/ (offset inode-n superblock)
                                           (bytes-per-block superblock))))
                              n-blocks))
           (offset (mod (offset inode-n superblock) (bytes-per-block superblock))))
      (make-inode :mode (sys.int::ub16ref/le block (+ 0 offset))
                  :uid (sys.int::ub16ref/le block (+ 2 offset))
                  :size (sys.int::ub32ref/le block (+ 4 offset))
  