fs(4)

#define FS_MAGIC 0x011954 #define FS_MAGIC_LFN 0x095014 #define FS_CLEAN 0x17 #define FS_OK 0x53 #define FS_NOTOK 0x31 struct fs { struct fs *fs_link; /* linked list of file systems */ struct fs *fs_rlink; /* used for incore super blocks */ daddr_t fs_sblkno; /* addr of super-block in filesys */ daddr_t fs_cblkno; /* offset of cyl-block in filesys */ daddr_t fs_iblkno; /* offset of inode-blocks in filesys*/ daddr_t fs_dblkno; /* offset of first data after cg */ long fs_cgoffset; /* cylinder group offset in cylinder*/ long fs_cgmask; /* used to calc mod fs_ntrak */ time_t fs_time; /* last time written */ long fs_size; /* number of blocks in fs */ long fs_dsize; /* number of data blocks in fs */ long fs_ncg; /* number of cylinder groups */ long fs_bsize; /* size of basic blocks in fs */ long fs_fsize; /* size of frag blocks in fs */ long fs_frag; /* number of frags in a block in fs*/ /* these are configuration parameters */ long fs_minfree; /* minimum percentage of free blocks*/ long fs_rotdelay; /* num of ms for optimal next block */ long fs_rps; /* disk revolutions per second */ /* these fields can be computed from the others */ long fs_bmask; /* ``blkoff'' calc of blk offsets */ long fs_fmask; /* ``fragoff'' calc of frag offsets */ long fs_bshift; /* ``lblkno'' calc of logical blkno */ long fs_fshift; /* ``numfrags'' calc number of frags*/ /* these are configuration parameters */ long fs_maxcontig; /* max number of contiguous blks */ long fs_maxbpg; /* max number of blks per cyl group */ /* these fields can be computed from the others */ long fs_fragshift; /* block to frag shift */ long fs_fsbtodb; /* fsbtodb and dbtofsb shift constant*/ long fs_sbsize; /* actual size of super block */ long fs_csmask; /* csum block offset */ long fs_csshift; /* csum block number */ long fs_nindir; /* value of NINDIR */ long fs_inopb; /* value of INOPB */ long fs_nspf; /* value of NSPF */ long fs_sparecon[6]; /* reserved for future constants */ /* sizes determined by number of cylinder groups and their sizes */ daddr_t fs_csaddr; /* blk addr of cyl grp summary area */ long fs_cssize; /* size of cyl grp summary area */ long fs_cgsize; /* cylinder group size */ /* these fields should be derived from the hardware */ long fs_ntrak; /* tracks per cylinder */ long fs_nsect; /* sectors per track */ long fs_spc; /* sectors per cylinder */ /* this comes from the disk driver partitioning */ long fs_ncyl; /* cylinders in file system */ /* these fields can be computed from the others */ long fs_cpg; /* cylinders per group */ long fs_ipg; /* inodes per group */ long fs_fpg; /* blocks per group * fs_frag */ /* this data must be re-computed after crashes */ struct csum fs_cstotal; /* cylinder summary information */ /* these fields are cleared at mount time */ char fs_fmod; /* super block modified flag */ char fs_clean; /* file system is clean flag */ char fs_ronly; /* mounted read-only flag */ char fs_flags; /* currently unused flag */ char fs_fsmnt[MAXMNTLEN];/* name mounted on */ /* these fields retain the current block allocation info */ long fs_cgrotor; /* last cg searched */ struct csum *fs_csp[MAXCSBUFS]; /* list of fs_cs info buffers */ long fs_cpc; /* cyl per cycle in postbl */ short fs_postbl[MAXCPG][NRPOS];/*head of blocks per rotation */ long fs_magic; /* magic number */ char fs_fname[6]; /* name of file system */ char fs_fpack[6]; /* pack name of file system */ u_char fs_rotbl[1]; /* list of blocks for each rotation */ /* actually longer */ };