usr/src/sys/ufs/lfs/lfs.h

/*-
 * Copyright (c) 1991 The Regents of the University of California.
 * All rights reserved.
 *
 * %sccs.include.redist.c%
 *
 *      @(#)lfs.h       5.3 (Berkeley) %G%
 */

#define LFS_LABELPAD    8192            /* LFS label size */
#define LFS_SBPAD       8192            /* LFS superblock size */
#define MAXMNTLEN       512             /* XXX move from fs.h to mount.h */

/* On-disk and in-memory checkpoint segment usage structure. */
typedef struct segusage {
        u_long  su_nbytes;              /* number of live bytes */
        u_long  su_lastmod;             /* last modified timestamp */
#define SEGUSE_DIRTY                    0x1
        u_long  su_flags;
} SEGUSE;

/* On-disk and in-memory super block. */
typedef struct lfs {
#define LFS_MAGIC       0xbedead
        u_long  lfs_magic;              /* magic number */
#define LFS_VERSION     1
        u_long  lfs_version;            /* version number */

        u_long  lfs_size;               /* number of blocks in fs */
        u_long  lfs_ssize;              /* number of blocks per segment */
        u_long  lfs_dsize;              /* number of data blocks in fs */
        u_long  lfs_bsize;              /* size of basic blocks in fs */
        u_long  lfs_fsize;              /* size of frag blocks in fs */
        u_long  lfs_frag;               /* number of frags in a block in fs */

/* Checkpoint region. */
        ino_t   lfs_free;               /* start of the free list */
        u_long  lfs_bfree;              /* number of free blocks */
        u_long  lfs_nfiles;             /* number of allocated inodes */
        daddr_t lfs_idaddr;             /* inode file disk address */
        ino_t   lfs_ifile;              /* inode file inode number */
        daddr_t lfs_lastseg;            /* last segment written */
        daddr_t lfs_nextseg;            /* next segment to write */
        u_long  lfs_tstamp;             /* time stamp */

/* These are configuration parameters. */
        u_long  lfs_minfree;            /* minimum percentage of free blocks */

/* These fields can be computed from the others. */
        u_long  lfs_inopb;              /* inodes per block */
        u_long  lfs_ifpb;               /* IFILE entries per block */
        u_long  lfs_nindir;             /* indirect pointers per block */
        u_long  lfs_nseg;               /* number of segments */
        u_long  lfs_nspf;               /* number of sectors per fragment */
        u_long  lfs_segtabsz;           /* segment table size in blocks */

        u_long  lfs_segmask;            /* calculate offset within a segment */
        u_long  lfs_segshift;           /* fast mult/div for segments */
        u_long  lfs_bmask;              /* calc block offset from file offset */
        u_long  lfs_bshift;             /* calc block number from file offset */
        u_long  lfs_ffmask;             /* calc frag offset from file offset */
        u_long  lfs_ffshift;            /* fast mult/div for frag from file */
        u_long  lfs_fbmask;             /* calc frag offset from block offset */
        u_long  lfs_fbshift;            /* fast mult/div for frag from block */
        u_long  lfs_fsbtodb;            /* fsbtodb and dbtofsb shift constant */

#define LFS_MIN_SBINTERVAL      5       /* minimum superblock segment spacing */
#define LFS_MAXNUMSB            10      /* superblock disk offsets */
        daddr_t lfs_sboffs[LFS_MAXNUMSB];

/* These fields are set at mount time and are meaningless on disk. */
        struct vnode *lfs_ivnode;       /* vnode for the ifile */
        SEGUSE  *lfs_segtab;            /* in-memory segment usage table */
        u_char  lfs_fmod;               /* super block modified flag */
        u_char  lfs_clean;              /* file system is clean flag */
        u_char  lfs_ronly;              /* mounted read-only flag */
        u_char  lfs_flags;              /* currently unused flag */
        u_char  lfs_fsmnt[MAXMNTLEN];   /* name mounted on */
        u_char  pad[3];                 /* long-align */

/* Checksum; valid on disk. */
        u_long  lfs_cksum;              /* checksum for superblock checking */
} LFS;

/*
 * The root inode is the root of the file system.  Inode 0 is the out-of-band
 * inode, and inode 1 is the inode number for the ifile.  Thus the root inode
 * is 2.
 */
#define ROOTINO         ((ino_t)2)
#define LOSTFOUNDINO    ((ino_t)3)

/* Fixed inode numbers. */
#define LFS_UNUSED_INUM 0               /* Out of band inode number. */
#define LFS_IFILE_INUM  1               /* Inode number of the ifile. */
                                        /* First free inode number. */
#define LFS_FIRST_INUM  (LOSTFOUNDINO + 1)

/*
 * Used to access the first spare of the dinode which we use to store
 * the ifile number so we can identify them
 */
#define di_inum di_spare[0]

typedef struct ifile {
        u_long  if_version;             /* inode version number */
#define LFS_UNUSED_DADDR        0       /* out-of-band daddr */
        daddr_t if_daddr;               /* inode disk address */
        union {
                ino_t   nextfree;       /* next-unallocated inode */
                time_t  st_atime;       /* access time */
        } __ifile_u;
#define if_st_atime     __ifile_u.st_atime
#define if_nextfree     __ifile_u.nextfree
} IFILE;

/* Segment table size, in blocks. */
#define SEGTABSIZE(fs) \
        (((fs)->fs_nseg * sizeof(SEGUSE) + \
            ((fs)->fs_bsize - 1)) >> (fs)->fs_bshift)

#define SEGTABSIZE_SU(fs) \
        (((fs)->lfs_nseg * sizeof(SEGUSE) + \
            ((fs)->lfs_bsize - 1)) >> (fs)->lfs_bshift)

/*
 * All summary blocks are the same size, so we can always read a summary
 * block easily from a segment
 */
#define LFS_SUMMARY_SIZE        512

/* On-disk segment summary information */
typedef struct segsum {
        u_long  ss_cksum;               /* check sum */
        daddr_t ss_next;                /* next segment */
        daddr_t ss_prev;                /* next segment */
        daddr_t ss_nextsum;             /* next summary block */
        u_long  ss_create;              /* creation time stamp */
        u_long  ss_nfinfo;              /* number of file info structures */
        u_long  ss_ninos;               /* number of inode blocks */
        /* FINFO's... */
} SEGSUM;

/* On-disk file information.  One per file with data blocks in the segment. */
typedef struct finfo {
        u_long  fi_nblocks;             /* number of blocks */
        u_long  fi_version;             /* version number */
        ino_t   fi_ino;                 /* inode number */
        u_long  fi_blocks[1];           /* array of logical block numbers */
} FINFO;

/* NINDIR is the number of indirects in a file system block. */
#define NINDIR(fs)      ((fs)->lfs_nindir)

/* INOPB is the number of inodes in a secondary storage block. */
#define INOPB(fs)       ((fs)->lfs_inopb)

/* IFPB -- IFILE's per block */
#define IFPB(fs)        ((fs)->lfs_ifpb)

#define blksize(fs)             ((fs)->lfs_bsize)
#define blkoff(fs, loc)         ((loc) & (fs)->lfs_bmask)
#define fsbtodb(fs, b)          ((b) << (fs)->lfs_fsbtodb)
#define lblkno(fs, loc)         ((loc) >> (fs)->lfs_bshift)
#define lblktosize(fs, blk)     ((blk) << (fs)->lfs_bshift)