sys/pcfs/pcfsmount.h

/*
 *  Written by Paul Popelka (paulp@uts.amdahl.com)
 *
 *  You can do anything you want with this software,
 *    just don't say you wrote it,
 *    and don't remove this notice.
 *
 *  This software is provided "as is".
 *
 *  The author supplies this software to be publicly
 *  redistributed on the understanding that the author
 *  is not responsible for the correct functioning of
 *  this software in any circumstances and is not liable
 *  for any damages caused by this software.
 *
 *  October 1992
 *
 *      $Id$
 */

/*
 *  Layout of the mount control block for a msdos
 *  file system.
 */
struct pcfsmount {
        struct mount *pm_mountp;        /* vfs mount struct for this fs */
        dev_t pm_dev;                   /* block special device mounted */
        struct vnode *pm_devvp;         /* vnode for block device mntd  */
        struct bpb50 pm_bpb;            /* BIOS parameter blk for this fs */
        u_long pm_fatblk;               /* block # of first FAT         */
        u_long pm_rootdirblk;           /* block # of root directory    */
        u_long pm_rootdirsize;          /* size in blocks (not clusters) */
        u_long pm_firstcluster;         /* block number of first cluster */
        u_long pm_nmbrofclusters;       /* # of clusters in filesystem  */
        u_long pm_maxcluster;           /* maximum cluster number       */
        u_long pm_freeclustercount;     /* number of free clusters      */
        u_long pm_lookhere;             /* start free cluster search here */
        u_long pm_bnshift;              /* shift file offset right this
                                         *  amount to get a block number */
        u_long pm_brbomask;             /* and a file offset with this
                                         *  mask to get block rel offset */
        u_long pm_cnshift;              /* shift file offset right this
                                         *  amount to get a cluster number */
        u_long pm_crbomask;             /* and a file offset with this
                                         *  mask to get cluster rel offset */
        u_long pm_bpcluster;            /* bytes per cluster            */
        u_long pm_depclust;             /* directory entries per cluster */
        u_long pm_fmod;                 /* ~0 if fs is modified, this can
                                         * rollover to 0                */
        u_long pm_fatblocksize;         /* size of fat blocks in bytes */
        u_long pm_fatblocksec;          /* size of fat blocks in sectors */
        u_long pm_fatsize;              /* size of fat in bytes */
        u_char *pm_inusemap;            /* ptr to bitmap of in-use clusters */
        char pm_ronly;                  /* read only if non-zero        */
        char pm_waitonfat;              /* wait for writes of the fat to complt,
                                         * when 0 use bdwrite, else use bwrite */
};
/*
 *  How to compute pm_cnshift and pm_crbomask.
 *
 *  pm_crbomask = (pm_SectPerClust * pm_BytesPerSect) - 1
 *  if (bytesperclust == 0) return EBADBLKSZ;
 *  bit = 1;
 *  for (i = 0; i < 32; i++) {
 *    if (bit & bytesperclust) {
 *      if (bit ^ bytesperclust) return EBADBLKSZ;
 *      pm_cnshift = i;
 *      break;
 *    }
 *    bit <<= 1;
 * }
 */

/*
 *  Shorthand for fields in the bpb contained in
 *  the pcfsmount structure.
 */
#define pm_BytesPerSec  pm_bpb.bpbBytesPerSec
#define pm_SectPerClust pm_bpb.bpbSecPerClust
#define pm_ResSectors   pm_bpb.bpbResSectors
#define pm_FATs         pm_bpb.bpbFATs
#define pm_RootDirEnts  pm_bpb.bpbRootDirEnts
#define pm_Sectors      pm_bpb.bpbSectors
#define pm_Media        pm_bpb.bpbMedia
#define pm_FATsecs      pm_bpb.bpbFATsecs
#define pm_SecPerTrack  pm_bpb.bpbSecPerTrack
#define pm_Heads        pm_bpb.bpbHeads
#define pm_HiddenSects  pm_bpb.bpbHiddenSecs
#define pm_HugeSectors  pm_bpb.bpbHugeSectors

/*
 *  Map a cluster number into a filesystem relative
 *  block number.
 */
#define cntobn(pmp, cn) \
        ((((cn)-CLUST_FIRST) * (pmp)->pm_SectPerClust) + (pmp)->pm_firstcluster)

/*
 *  Map a filesystem relative block number back into
 *  a cluster number.
 */
#define bntocn(pmp, bn) \
        ((((bn) - pmp->pm_firstcluster)/ (pmp)->pm_SectPerClust) + CLUST_FIRST)

/*
 * Calculate block number for directory entry in root dir, offset dirofs
 */
#define roottobn(pmp, dirofs) \
        (((dirofs) / (pmp)->pm_depclust) * (pmp)->pm_SectPerClust \
        + (pmp)->pm_rootdirblk)

/*
 * Calculate block number for directory entry at cluster dirclu, offset dirofs
 */
#define detobn(pmp, dirclu, dirofs) \
        ((dirclu) == PCFSROOT \
         ? roottobn((pmp), (dirofs)) \
         : cntobn((pmp), (dirclu)))

/*
 * Convert pointer to buffer -> pointer to direntry
 */
#define bptoep(pmp, bp, dirofs) \
        ((struct direntry *)((bp)->b_un.b_addr) \
         + (dirofs) % (pmp)->pm_depclust)


/*
 * Prototypes for PCFS virtual filesystem operations
 */
int pcfs_mount __P((struct mount *mp, char *path, caddr_t data,
        struct nameidata *ndp, struct proc *p));
int pcfs_start __P((struct mount *mp, int flags, struct proc *p));
int pcfs_unmount __P((struct mount *mp, int mntflags, struct proc *p));
int pcfs_root __P((struct mount *mp, struct vnode **vpp));
int pcfs_quotactl __P((struct mount *mp, int cmds, int uid, /* should be uid_t */
        caddr_t arg, struct proc *p));
int pcfs_statfs __P((struct mount *mp, struct statfs *sbp, struct proc *p));
int pcfs_sync __P((struct mount *mp, int waitfor));
int pcfs_fhtovp __P((struct mount *mp, struct fid *fhp, struct vnode **vpp));
int pcfs_vptofh __P((struct vnode *vp, struct fid *fhp));
int pcfs_init __P(());