root/usr.sbin/makefs/msdos/msdosfsmount.h
/*      $OpenBSD: msdosfsmount.h,v 1.1 2016/10/18 17:05:30 natano Exp $ */
/*      $NetBSD: msdosfsmount.h,v 1.21 2016/01/30 09:59:27 mlelstv Exp $        */

/*-
 * Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank.
 * Copyright (C) 1994, 1995, 1997 TooLs GmbH.
 * All rights reserved.
 * Original code by Paul Popelka (paulp@uts.amdahl.com) (see below).
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by TooLs GmbH.
 * 4. The name of TooLs GmbH may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
/*
 * 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
 */

#ifndef _MSDOSFS_MSDOSFSMOUNT_H_
#define _MSDOSFS_MSDOSFSMOUNT_H_


/*
 * Msdosfs mount options:
 */
#define MSDOSFSMNT_SHORTNAME    1       /* Force old DOS short names only */
#define MSDOSFSMNT_LONGNAME     2       /* Force Win'95 long names */
#define MSDOSFSMNT_NOWIN95      4       /* Completely ignore Win95 entries */
#define MSDOSFSMNT_VERSIONED    16      /* Struct is versioned */

/* All flags above: */
#define MSDOSFSMNT_MNTOPT \
        (MSDOSFSMNT_SHORTNAME|MSDOSFSMNT_LONGNAME|MSDOSFSMNT_NOWIN95 \
         |MSDOSFSMNT_VERSIONED)

#define MSDOSFSMNT_RONLY        0x80000000      /* mounted read-only    */
#define MSDOSFSMNT_WAITONFAT    0x40000000      /* mounted synchronous  */
#define MSDOSFS_FATMIRROR       0x20000000      /* FAT is mirrored */


/*
 * Layout of the mount control block for a MSDOSFS file system.
 */
struct msdosfsmount {
        struct mount *pm_mountp;/* vfs mount struct for this fs */
        dev_t pm_dev;           /* block special device mounted */
        uid_t pm_uid;           /* uid to set as owner of the files */
        gid_t pm_gid;           /* gid to set as owner of the files */
        mode_t pm_mask;         /* mask to and with file protection bits
                                   for files */
        mode_t pm_dirmask;      /* mask to and with file protection bits
                                   for directories */
        int pm_minuteswest;     /* of Greenwitch */
        struct mkfsvnode *pm_devvp;     /* mkfsvnode for block device mntd */
        struct bpb50 pm_bpb;    /* BIOS parameter blk for this fs */
        u_long pm_FATsecs;      /* actual number of FAT sectors */
        u_long pm_fatblk;       /* sector # of first FAT */
        u_long pm_rootdirblk;   /* sector # (cluster # for FAT32) of root directory number */
        u_long pm_rootdirsize;  /* size in sectors (not clusters) */
        u_long pm_firstcluster; /* sector 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_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_bnshift;      /* shift file offset right this amount to get a sector number */
        u_long pm_bpcluster;    /* bytes 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_long pm_fatmask;      /* mask to use for FAT numbers */
        u_long pm_fsinfo;       /* fsinfo block number */
        u_long pm_nxtfree;      /* next free cluster in fsinfo block */
        u_int pm_fatmult;       /* these 2 values are used in FAT */
        u_int pm_fatdiv;        /*      offset computation */
        u_int pm_curfat;        /* current FAT for FAT32 (0 otherwise) */
        u_int *pm_inusemap;     /* ptr to bitmap of in-use clusters */
        u_int pm_flags;         /* see below */
};
/* Byte offset in FAT on filesystem pmp, cluster cn */
#define FATOFS(pmp, cn) ((cn) * (pmp)->pm_fatmult / (pmp)->pm_fatdiv)

#define VFSTOMSDOSFS(mp)        ((struct msdosfsmount *)mp->mnt_data)

/* Number of bits in one pm_inusemap item: */
#define N_INUSEBITS     (8 * sizeof(u_int))

/*
 * Shorthand for fields in the bpb contained in the msdosfsmount structure.
 */
#define pm_BytesPerSec  pm_bpb.bpbBytesPerSec
#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_SecPerTrack  pm_bpb.bpbSecPerTrack
#define pm_Heads        pm_bpb.bpbHeads
#define pm_HiddenSects  pm_bpb.bpbHiddenSecs
#define pm_HugeSectors  pm_bpb.bpbHugeSectors

/*
 * Convert pointer to buffer -> pointer to direntry
 */
#define bptoep(pmp, bp, dirofs) \
        ((struct direntry *)(((char *)(bp)->b_data)     \
         + ((dirofs) & (pmp)->pm_crbomask)))

/*
 * Convert sector number to cluster number
 */
#define de_bn2cn(pmp, bn) \
        ((bn) >> ((pmp)->pm_cnshift - (pmp)->pm_bnshift))

/*
 * Convert cluster number to sector number
 */
#define de_cn2bn(pmp, cn) \
        ((cn) << ((pmp)->pm_cnshift - (pmp)->pm_bnshift))

/*
 * Convert sector number to kernel block number
 */
#define de_bn2kb(pmp, bn) \
        ((bn) << ((pmp)->pm_bnshift - DEV_BSHIFT))

/*
 * Convert kernel block number to sector number
 */
#define de_kb2bn(pmp, kb) \
        ((kb) >> ((pmp)->pm_bnshift - DEV_BSHIFT))

/*
 * Convert file offset to cluster number
 */
#define de_cluster(pmp, off) \
        ((off) >> (pmp)->pm_cnshift)

/*
 * Clusters required to hold size bytes
 */
#define de_clcount(pmp, size) \
        (((size) + (pmp)->pm_bpcluster - 1) >> (pmp)->pm_cnshift)

/*
 * Convert file offset to sector number
 */
#define de_blk(pmp, off) \
        (de_cn2bn(pmp, de_cluster((pmp), (off))))

/*
 * Convert cluster number to file offset
 */
#define de_cn2off(pmp, cn) \
        ((cn) << (pmp)->pm_cnshift)

/*
 * Convert sector number to file offset
 */
#define de_bn2off(pmp, bn) \
        ((bn) << (pmp)->pm_bnshift)
/*
 * Map a cluster number into a filesystem relative sector number.
 */
#define cntobn(pmp, cn) \
        (de_cn2bn((pmp), (cn)-CLUST_FIRST) + (pmp)->pm_firstcluster)

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

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

/*
 * Prototypes for MSDOSFS virtual filesystem operations
 */
void msdosfs_init(void);
void msdosfs_reinit(void);
void msdosfs_done(void);


#endif /* _MSDOSFS_MSDOSFSMOUNT_H_ */