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review.evervolv.com / android_kernel_lge_hammerhead / 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 / . / drivers / char / ftape / zftape / zftape-vtbl.h
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Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame^]1#ifndef _ZFTAPE_VTBL_H
2#define _ZFTAPE_VTBL_H
3
4/*
5 * Copyright (c) 1995-1997 Claus-Justus Heine
6
7 This program is free software; you can redistribute it and/or
8 modify it under the terms of the GNU General Public License as
9 published by the Free Software Foundation; either version 2, or (at
10 your option) any later version.
11
12 This program is distributed in the hope that it will be useful, but
13 WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 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,
20 USA.
21
22 *
23 * $Source: /homes/cvs/ftape-stacked/ftape/zftape/zftape-vtbl.h,v $
24 * $Revision: 1.3 $
25 * $Date: 1997/10/28 14:30:09 $
26 *
27 * This file defines a volume table as defined in the QIC-80
28 * development standards.
29 */
30
31#include <linux/list.h>
32
33#include "../lowlevel/ftape-tracing.h"
34
35#include "../zftape/zftape-eof.h"
36#include "../zftape/zftape-ctl.h"
37#include "../zftape/zftape-rw.h"
38
39#define VTBL_SIZE 128 /* bytes */
40
41/* The following are offsets in the vtbl. */
42#define VTBL_SIG 0
43#define VTBL_START 4
44#define VTBL_END 6
45#define VTBL_DESC 8
46#define VTBL_DATE 52
47#define VTBL_FLAGS 56
48#define VTBL_FL_VENDOR_SPECIFIC (1<<0)
49#define VTBL_FL_MUTLI_CARTRIDGE (1<<1)
50#define VTBL_FL_NOT_VERIFIED (1<<2)
51#define VTBL_FL_REDIR_INHIBIT (1<<3)
52#define VTBL_FL_SEG_SPANNING (1<<4)
53#define VTBL_FL_DIRECTORY_LAST (1<<5)
54#define VTBL_FL_RESERVED_6 (1<<6)
55#define VTBL_FL_RESERVED_7 (1<<7)
56#define VTBL_M_NO 57
57#define VTBL_EXT 58
58#define EXT_ZFTAPE_SIG 0
59#define EXT_ZFTAPE_BLKSZ 10
60#define EXT_ZFTAPE_CMAP 12
61#define EXT_ZFTAPE_QIC113 13
62#define VTBL_PWD 84
63#define VTBL_DIR_SIZE 92
64#define VTBL_DATA_SIZE 96
65#define VTBL_OS_VERSION 104
66#define VTBL_SRC_DRIVE 106
67#define VTBL_DEV 122
68#define VTBL_RESERVED_1 123
69#define VTBL_CMPR 124
70#define VTBL_CMPR_UNREG 0x3f
71#define VTBL_CMPR_USED 0x80
72#define VTBL_FMT 125
73#define VTBL_RESERVED_2 126
74#define VTBL_RESERVED_3 127
75/* compatibility with pre revision K */
76#define VTBL_K_CMPR 120
77
78/* the next is used by QIC-3020 tapes with format code 6 (>2^16
79 * segments) It is specified in QIC-113, Rev. G, Section 5 (SCSI
80 * volume table). The difference is simply, that we only store the
81 * number of segments used, not the starting segment.
82 */
83#define VTBL_SCSI_SEGS 4 /* is a 4 byte value */
84
85/* one vtbl is 128 bytes, that results in a maximum number of
86 * 29*1024/128 = 232 volumes.
87 */
88#define ZFT_MAX_VOLUMES (FT_SEGMENT_SIZE/VTBL_SIZE)
89#define VTBL_ID "VTBL"
90#define VTBL_IDS { VTBL_ID, "XTBL", "UTID", "EXVT" } /* other valid ids */
91#define ZFT_VOL_NAME "zftape volume" /* volume label used by me */
92#define ZFTAPE_SIG "LINUX ZFT"
93
94/* global variables
95 */
96typedef struct zft_internal_vtbl
97{
98 struct list_head node;
99 int count;
100 unsigned int start_seg; /* 32 bits are enough for now */
101 unsigned int end_seg; /* 32 bits are enough for now */
102 __s64 size; /* uncompressed size */
103 unsigned int blk_sz; /* block size for this volume */
104 unsigned int zft_volume :1; /* zftape created this volume */
105 unsigned int use_compression:1; /* compressed volume */
106 unsigned int qic113 :1; /* layout of compressed block
107 * info and vtbl conforms to
108 * QIC-113, Rev. G
109 */
110 unsigned int new_volume :1; /* it was created by us, this
111 * run. this allows the
112 * fields that aren't really
113 * used by zftape to be filled
114 * in by some user level
115 * program.
116 */
117 unsigned int open :1; /* just in progress of being
118 * written
119 */
120} zft_volinfo;
121
122extern struct list_head zft_vtbl;
123#define zft_head_vtbl list_entry(zft_vtbl.next, zft_volinfo, node)
124#define zft_eom_vtbl list_entry(zft_vtbl.prev, zft_volinfo, node)
125#define zft_last_vtbl list_entry(zft_eom_vtbl->node.prev, zft_volinfo, node)
126#define zft_first_vtbl list_entry(zft_head_vtbl->node.next, zft_volinfo, node)
127#define zft_vtbl_empty (zft_eom_vtbl->node.prev == &zft_head_vtbl->node)
128
129#define DUMP_VOLINFO(level, desc, info) \
130{ \
131 char tmp[21]; \
132 strlcpy(tmp, desc, sizeof(tmp)); \
133 TRACE(level, "Volume %d:\n" \
134 KERN_INFO "description : %s\n" \
135 KERN_INFO "first segment: %d\n" \
136 KERN_INFO "last segment: %d\n" \
137 KERN_INFO "size : " LL_X "\n" \
138 KERN_INFO "block size : %d\n" \
139 KERN_INFO "compression : %d\n" \
140 KERN_INFO "zftape volume: %d\n" \
141 KERN_INFO "QIC-113 conf.: %d", \
142 (info)->count, tmp, (info)->start_seg, (info)->end_seg, \
143 LL((info)->size), (info)->blk_sz, \
144 (info)->use_compression != 0, (info)->zft_volume != 0, \
145 (info)->qic113 != 0); \
146}
147
148extern int zft_qic_mode;
149extern int zft_old_ftape;
150extern int zft_volume_table_changed;
151
152/* exported functions */
153extern void zft_init_vtbl (void);
154extern void zft_free_vtbl (void);
155extern int zft_extract_volume_headers(__u8 *buffer);
156extern int zft_update_volume_table (unsigned int segment);
157extern int zft_open_volume (zft_position *pos,
158 int blk_sz, int use_compression);
159extern int zft_close_volume (zft_position *pos);
160extern const zft_volinfo *zft_find_volume(unsigned int seg_pos);
161extern int zft_skip_volumes (int count, zft_position *pos);
162extern __s64 zft_get_eom_pos (void);
163extern void zft_skip_to_eom (zft_position *pos);
164extern int zft_fake_volume_headers (eof_mark_union *eof_map,
165 int num_failed_sectors);
166extern int zft_weof (unsigned int count, zft_position *pos);
167extern void zft_move_past_eof (zft_position *pos);
168
169static inline int zft_tape_at_eod (const zft_position *pos);
170static inline int zft_tape_at_lbot (const zft_position *pos);
171static inline void zft_position_before_eof (zft_position *pos,
172 const zft_volinfo *volume);
173static inline __s64 zft_check_for_eof(const zft_volinfo *vtbl,
174 const zft_position *pos);
175
176/* this function decrements the zft_seg_pos counter if we are right
177 * at the beginning of a segment. This is to handle fsfm/bsfm -- we
178 * need to position before the eof mark. NOTE: zft_tape_pos is not
179 * changed
180 */
181static inline void zft_position_before_eof(zft_position *pos,
182 const zft_volinfo *volume)
183{
184 TRACE_FUN(ft_t_flow);
185
186 if (pos->seg_pos == volume->end_seg + 1 && pos->seg_byte_pos == 0) {
187 pos->seg_pos --;
188 pos->seg_byte_pos = zft_get_seg_sz(pos->seg_pos);
189 }
190 TRACE_EXIT;
191}
192
193/* Mmmh. Is the position at the end of the last volume, that is right
194 * before the last EOF mark also logical an EOD condition?
195 */
196static inline int zft_tape_at_eod(const zft_position *pos)
197{
198 TRACE_FUN(ft_t_any);
199
200 if (zft_qic_mode) {
201 TRACE_EXIT (pos->seg_pos >= zft_eom_vtbl->start_seg ||
202 zft_last_vtbl->open);
203 } else {
204 TRACE_EXIT pos->seg_pos > ft_last_data_segment;
205 }
206}
207
208static inline int zft_tape_at_lbot(const zft_position *pos)
209{
210 if (zft_qic_mode) {
211 return (pos->seg_pos <= zft_first_vtbl->start_seg &&
212 pos->volume_pos == 0);
213 } else {
214 return (pos->seg_pos <= ft_first_data_segment &&
215 pos->volume_pos == 0);
216 }
217}
218
219/* This one checks for EOF. return remaing space (may be negative)
220 */
221static inline __s64 zft_check_for_eof(const zft_volinfo *vtbl,
222 const zft_position *pos)
223{
224 return (__s64)(vtbl->size - pos->volume_pos);
225}
226
227#endif /* _ZFTAPE_VTBL_H */