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1 | #ifndef _ZFTAPE_RW_H |
2 | #define _ZFTAPE_RW_H | |
3 | ||
4 | /* | |
5 | * Copyright (C) 1996, 1997 Claus-Justus Heine. | |
6 | ||
7 | This program is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
9 | the Free Software Foundation; either version 2, or (at your option) | |
10 | any later version. | |
11 | ||
12 | This program is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with this program; see the file COPYING. If not, write to | |
19 | the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. | |
20 | ||
21 | * | |
22 | * $Source: /homes/cvs/ftape-stacked/ftape/zftape/zftape-rw.h,v $ | |
23 | * $Revision: 1.2 $ | |
24 | * $Date: 1997/10/05 19:19:09 $ | |
25 | * | |
26 | * This file contains the definitions for the read and write | |
27 | * functions for the QIC-117 floppy-tape driver for Linux. | |
28 | * | |
29 | */ | |
30 | ||
31 | #include <linux/config.h> /* for CONFIG_ZFT_DFLT_BLK_SZ */ | |
32 | #include "../zftape/zftape-buffers.h" | |
33 | ||
34 | #define SEGMENTS_PER_TAPE (ft_segments_per_track * ft_tracks_per_tape) | |
35 | ||
36 | /* QIC-113 Rev. G says that `a maximum of 63488 raw bytes may be | |
37 | * compressed into a single frame'. | |
38 | * Maybe we should stick to 32kb to make it more `beautiful' | |
39 | */ | |
40 | #define ZFT_MAX_BLK_SZ (62*1024) /* bytes */ | |
41 | #if !defined(CONFIG_ZFT_DFLT_BLK_SZ) | |
42 | # define CONFIG_ZFT_DFLT_BLK_SZ (10*1024) /* bytes, default of gnu tar */ | |
43 | #elif CONFIG_ZFT_DFLT_BLK_SZ == 0 | |
44 | # undef CONFIG_ZFT_DFLT_BLK_SZ | |
45 | # define CONFIG_ZFT_DFLT_BLK_SZ 1 | |
46 | #elif (CONFIG_ZFT_DFLT_BLK_SZ % 1024) != 0 | |
47 | # error CONFIG_ZFT_DFLT_BLK_SZ must be 1 or a multiple of 1024 | |
48 | #endif | |
49 | /* The *optional* compression routines need some overhead per tape | |
50 | * block for their purposes. Instead of asking the actual compression | |
51 | * implementation how much it needs, we restrict this overhead to be | |
52 | * maximal of ZFT_CMPT_OVERHEAD size. We need this for EOT | |
53 | * conditions. The tape is assumed to be logical at EOT when the | |
54 | * distance from the physical EOT is less than | |
55 | * one tape block + ZFT_CMPR_OVERHEAD | |
56 | */ | |
57 | #define ZFT_CMPR_OVERHEAD 16 /* bytes */ | |
58 | ||
59 | typedef enum | |
60 | { | |
61 | zft_idle = 0, | |
62 | zft_reading, | |
63 | zft_writing, | |
64 | } zft_status_enum; | |
65 | ||
66 | typedef struct /* all values measured in bytes */ | |
67 | { | |
68 | int seg_pos; /* segment currently positioned at */ | |
69 | int seg_byte_pos; /* offset in current segment */ | |
70 | __s64 tape_pos; /* real offset from BOT */ | |
71 | __s64 volume_pos; /* pos. in uncompressed data stream in | |
72 | * current volume | |
73 | */ | |
74 | } zft_position; | |
75 | ||
76 | extern zft_position zft_pos; | |
77 | extern __u8 *zft_deblock_buf; | |
78 | extern __u8 *zft_hseg_buf; | |
79 | extern int zft_deblock_segment; | |
80 | extern zft_status_enum zft_io_state; | |
81 | extern int zft_header_changed; | |
82 | extern int zft_qic113; /* conform to old specs. and old zftape */ | |
83 | extern int zft_use_compression; | |
84 | extern unsigned int zft_blk_sz; | |
85 | extern __s64 zft_capacity; | |
86 | extern unsigned int zft_written_segments; | |
87 | extern int zft_label_changed; | |
88 | ||
89 | /* zftape-rw.c exported functions | |
90 | */ | |
91 | extern unsigned int zft_get_seg_sz(unsigned int segment); | |
92 | extern void zft_set_flags(unsigned int minor_unit); | |
93 | extern int zft_calc_seg_byte_coord(int *seg_byte_pos, __s64 tape_pos); | |
94 | extern __s64 zft_calc_tape_pos(int segment); | |
95 | extern __s64 zft_get_capacity(void); | |
96 | extern void zft_update_label(__u8 *buffer); | |
97 | extern int zft_erase(void); | |
98 | extern int zft_verify_write_segments(unsigned int segment, | |
99 | __u8 *data, size_t size, __u8 *buffer); | |
100 | extern unsigned int zft_get_time(void); | |
101 | #endif /* _ZFTAPE_RW_H */ | |
102 |