fs(4)                         UNIX System V(bfs)                          fs(4)


NAME
      fs (bfs) - format of the bfs file system volume

SYNOPSIS
      #include <sys/types.h>
      #include <sys/fs/bfs.h>

DESCRIPTION
      The bfs superblock is stored on sector 0. Its format is:

         struct bdsuper
         {
             long bdsupbfsmagic;/* Magic number */
             offt bdsupstart;/* Filesystem data start offset */
             offt bdsupend;/* Filesystem data end offset */

             /*
              * Sanity words
              */
             daddrt bdcpfromblock;/* "From" block of current transfer */
             daddrt bdcptoblock;/* "To" block of current transfer */
             daddrt bdcpbfromblock;/* Backup of "from" block */
             daddrt bdcpbtoblock;/* Backup of "to" block */
         };

         #define BFSMAGIC   0xBADFACE/* bfs magic number */

      The sanity words are  used to promote sanity during compaction.  They are
      used by fsck(1M) to recover from a system crash at any point during
      compaction.  See "Storage Blocks under bfs" in the "The bfs File System"
      section of chapter 5 in the System Administratror's Guide for a
      description of compaction.

SEE ALSO
      bfs-specific inode(4)



















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