fs(4BFS)                       (BFS)                        fs(4BFS)


       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 bfs_bdsuphead
             {
               long   bh_bfsmagic;   /* Magic number */
               off_t  bh_start;      /* Filesystem data start offset */
               off_t  bh_end;        /* Filesystem data end offset */
             };
             /*
              * The sanity structure is used to promote sanity in compaction.  Used
              * correctly, a crash at any point during compaction is recoverable.
              */
             struct bfs_sanity
             {
               daddr_t fromblock;    /* "From" block of current transfer */
               daddr_t toblock;      /* "To" block of current transfer */
               daddr_t bfromblock;   /* Backup of "from" block */
               daddr_t btoblock;     /* Backup of "to" block */
             };
             struct bdsuper
             {
               struct bfs_bdsuphead bdsup_head;  /* Header info */
               struct bfs_sanity bdsup_sane;     /* Crash recovery info whilst
                                                          compacting */
               char    bdsup_fsname[6];          /* file system name */
               char    bdsup_volume[6];          /* file system volume name */
               long    bdsup_filler[118];        /* Padding */
             };
             #define BFS_MAGIC   0xBADFACE         /* bfs magic number */

             The sanity structure is used to promote sanity during
             compaction.  It is used by fsck(1M) to recover from a system
             crash at any point during compaction.

       REFERENCES
             bfs-specific inode(4BFS)




                           Copyright 1994 Novell, Inc.               Page 1