103 lines
3.6 KiB
C
103 lines
3.6 KiB
C
#ifndef _ZFTAPE_RW_H
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#define _ZFTAPE_RW_H
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/*
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* Copyright (C) 1996, 1997 Claus-Justus Heine.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; see the file COPYING. If not, write to
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the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
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*
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* $Source: /homes/cvs/ftape-stacked/ftape/zftape/zftape-rw.h,v $
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* $Revision: 1.2 $
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* $Date: 1997/10/05 19:19:09 $
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*
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* This file contains the definitions for the read and write
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* functions for the QIC-117 floppy-tape driver for Linux.
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*
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*/
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#include <linux/config.h> /* for CONFIG_ZFT_DFLT_BLK_SZ */
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#include "../zftape/zftape-buffers.h"
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#define SEGMENTS_PER_TAPE (ft_segments_per_track * ft_tracks_per_tape)
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/* QIC-113 Rev. G says that `a maximum of 63488 raw bytes may be
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* compressed into a single frame'.
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* Maybe we should stick to 32kb to make it more `beautiful'
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*/
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#define ZFT_MAX_BLK_SZ (62*1024) /* bytes */
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#if !defined(CONFIG_ZFT_DFLT_BLK_SZ)
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# define CONFIG_ZFT_DFLT_BLK_SZ (10*1024) /* bytes, default of gnu tar */
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#elif CONFIG_ZFT_DFLT_BLK_SZ == 0
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# undef CONFIG_ZFT_DFLT_BLK_SZ
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# define CONFIG_ZFT_DFLT_BLK_SZ 1
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#elif (CONFIG_ZFT_DFLT_BLK_SZ % 1024) != 0
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# error CONFIG_ZFT_DFLT_BLK_SZ must be 1 or a multiple of 1024
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#endif
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/* The *optional* compression routines need some overhead per tape
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* block for their purposes. Instead of asking the actual compression
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* implementation how much it needs, we restrict this overhead to be
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* maximal of ZFT_CMPT_OVERHEAD size. We need this for EOT
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* conditions. The tape is assumed to be logical at EOT when the
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* distance from the physical EOT is less than
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* one tape block + ZFT_CMPR_OVERHEAD
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*/
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#define ZFT_CMPR_OVERHEAD 16 /* bytes */
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typedef enum
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{
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zft_idle = 0,
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zft_reading,
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zft_writing,
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} zft_status_enum;
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typedef struct /* all values measured in bytes */
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{
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int seg_pos; /* segment currently positioned at */
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int seg_byte_pos; /* offset in current segment */
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__s64 tape_pos; /* real offset from BOT */
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__s64 volume_pos; /* pos. in uncompressed data stream in
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* current volume
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*/
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} zft_position;
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extern zft_position zft_pos;
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extern __u8 *zft_deblock_buf;
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extern __u8 *zft_hseg_buf;
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extern int zft_deblock_segment;
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extern zft_status_enum zft_io_state;
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extern int zft_header_changed;
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extern int zft_qic113; /* conform to old specs. and old zftape */
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extern int zft_use_compression;
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extern unsigned int zft_blk_sz;
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extern __s64 zft_capacity;
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extern unsigned int zft_written_segments;
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extern int zft_label_changed;
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/* zftape-rw.c exported functions
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*/
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extern unsigned int zft_get_seg_sz(unsigned int segment);
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extern void zft_set_flags(unsigned int minor_unit);
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extern int zft_calc_seg_byte_coord(int *seg_byte_pos, __s64 tape_pos);
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extern __s64 zft_calc_tape_pos(int segment);
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extern __s64 zft_get_capacity(void);
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extern void zft_update_label(__u8 *buffer);
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extern int zft_erase(void);
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extern int zft_verify_write_segments(unsigned int segment,
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__u8 *data, size_t size, __u8 *buffer);
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extern unsigned int zft_get_time(void);
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#endif /* _ZFTAPE_RW_H */
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