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/*

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 *

 */

#ifndef __MSDOS_H__

#define __MSDOS_H__

#include "dentry.h"

#include "inode.h"

#include "super.h"

#include "dentryop.h"

#include "inodeop.h"

#include "superop.h"

extern struct dentry_operations msdos_dentry_operations;

extern struct inode_operations  msdos_inode_ro_operations;

extern struct file_operations   msdos_file_ro_operations;

extern struct super_operations  msdos_super_operations;

extern struct inode_operations  msdos_inode_rw_operations;

extern struct file_operations   msdos_file_rw_operations;

/*

 * directory entry

 */

#define ATTR_RDONLY 0x01

#define ATTR_HIDDEN 0x02

#define ATTR_SYSTEM 0x04

#define ATTR_VOLUME 0x08

#define ATTR_DIR    0x10

#define ATTR_ARCH   0x20

struct directoryentry {

  __uint8_t  name[8];

  __uint8_t  ext[3];

  __uint8_t  attribute;

  __uint8_t  reserved[10];

  __uint16_t time;

  __uint16_t date;

  __uint16_t cluster;

  __uint32_t size;

} __attribute__ ((packed));

/* for debugging */

extern void msdos_dump_direntry(struct directoryentry *ptr);

/* directory entry types */

#define LASTENTRYCHAR   0x00

#define ERASEDENTRYCHAR 0xe5

extern __inline__ int msdos_islastentry(struct directoryentry *de)

{

  return (*((de)->name)==LASTENTRYCHAR);

}

extern __inline__ int msdos_isfreeentry(struct directoryentry *de)

{

  return (*((de)->name)==LASTENTRYCHAR||

          *((de)->name)==ERASEDENTRYCHAR);

}

extern __inline__ int msdos_isunvalidentry(struct directoryentry *de)

{

  return (*((de)->name)==ERASEDENTRYCHAR)||

    ((de)->attribute&ATTR_VOLUME)||

    (msdos_islastentry(de));

}

extern __inline__ void msdos_markentrybusy(struct directoryentry *de)

{

  *((de)->name)='~';

}

extern __inline__ void msdos_markentryfree(struct directoryentry *de)

{

  *((de)->name)=ERASEDENTRYCHAR;

}

/* */

extern int msdos_formatname(struct directoryentry *de, struct qstr *str);

/*

 * constants

 */

#define CLUSTER_MASK    0xffff0000

#define CLUSTER_SHIFT   16

#define DENTRY_MASK     0x0000ffff

#define DENTRY_SHIFT    0

#define ROOT_CLUSTER    0x0000

#define SPECIAL_CLUSTER 0x0001

#define FREE_CLUSTER    0xfffe

#define NO_CLUSTER      0xffff

#define DIRENTRYSIZE    32

#define SECTORSIZE      512

/* first cluster of a msdos volume */

#define STARTCLUSTER    2

/* these on msdos directory structure */

#define FREECLUSTER 0x0000

#define LASTCLUSTER 0xffff

#define BADCLUSTER  0xfff7

/* max numbers of fats for volume (that must be supported) */

#define MAXFATS         4

/*

 * 0x01230008 e' la 8' entry del 123 cluster

 * 0x00000000 e' la root dir (non ha entry)

 * 0x00010005 e' la 5' entry nella root

 */

#define CLUOFF2INODE(cluster,deoffs) ((((__uint32_t)cluster)<<CLUSTER_SHIFT)|\

                                       ((deoffs)&DENTRY_MASK)\

                                       )

#define INODE2CLUSTER(inode) ((__uint16_t)((inode)>>CLUSTER_SHIFT))

#define INODE2DEOFFS(inode)  ((__uint16_t)((inode)&DENTRY_MASK))

#define ROOT_INODE      CLUOFF2INODE(ROOT_CLUSTER,0)

/*

 *

 */

/* what is the logical sector of a cluster */

extern __inline__ __uint32_t msdos_cluster2sector(struct inode *in,

                                                  __uint16_t cluster)

{

  if (cluster==NO_CLUSTER||

      cluster==SPECIAL_CLUSTER||

      cluster==FREE_CLUSTER) return (__uint32_t)(-1);

  if (cluster==ROOT_CLUSTER) return MSDOS_SB(in->i_sb).lroot;

  return (cluster-2)*MSDOS_SB(in->i_sb).spc+MSDOS_SB(in->i_sb).ldata;  

}

/*

#define msdos_cluster2sector(in,cl) \

( \

 ((cl)==NO_CLUSTER||(cl)==SPECIAL_CLUSTER||(cl)==FREE_CLUSTER)? \

 (-1): \

 ( \

  ((cl)==ROOT_CLUSTER?) \

  MSDOS_SB((in-)>i_sb).lroot: \

  ((cl)-2)*MSDOS_SB((in)->i_sb).spc+MSDOS_SB((in)->i_sb).ldata \

 ) \

)

*/

__uint32_t msdos_cluster2sector(struct inode *in, __uint16_t cluster);

__uint16_t msdos_nextcluster(struct super_block *sb, __uint16_t cluster);

void msdos_freecluster(struct super_block *sb, __uint16_t cluster);

void msdos_lastcluster(struct super_block *sb, __uint16_t cluster);

__uint16_t msdos_addcluster(struct super_block *sb, __uint16_t lacluster);

void msdos_freeclusterchain(struct super_block *sb, __uint16_t cluster);

#endif