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 bdsup_bfsmagic;/* Magic number */
    off_t bdsup_start;/* Filesystem data start offset */
    off_t bdsup_end;/* Filesystem data end offset */

    /*
     * Sanity words
     */
    daddr_t bdcp_fromblock;/* "From" block of current transfer */
    daddr_t bdcp_toblock;/* "To" block of current transfer */
    daddr_t bdcpb_fromblock;/* Backup of "from" block */
    daddr_t bdcpb_toblock;/* Backup of "to" block */
};

#define BFS_MAGIC   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)