drivers/char/ftape/zftape/zftape-vtbl.h

   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  */
  96 typedef 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
 122 extern 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
 148 extern int zft_qic_mode;
 149 extern int zft_old_ftape;
 150 extern int zft_volume_table_changed;
 151
 152 /* exported functions */
 153 extern void  zft_init_vtbl             (void);
 154 extern void  zft_free_vtbl             (void);
 155 extern int   zft_extract_volume_headers(__u8 *buffer);
 156 extern int   zft_update_volume_table   (unsigned int segment);
 157 extern int   zft_open_volume           (zft_position *pos,
 158                                         int blk_sz, int use_compression);
 159 extern int   zft_close_volume          (zft_position *pos);
 160 extern const zft_volinfo *zft_find_volume(unsigned int seg_pos);
 161 extern int   zft_skip_volumes          (int count, zft_position *pos);
 162 extern __s64 zft_get_eom_pos           (void);
 163 extern void  zft_skip_to_eom           (zft_position *pos);
 164 extern int   zft_fake_volume_headers   (eof_mark_union *eof_map,
 165                                         int num_failed_sectors);
 166 extern int   zft_weof                  (unsigned int count, zft_position *pos);
 167 extern void  zft_move_past_eof         (zft_position *pos);
 168
 169 static inline int   zft_tape_at_eod         (const zft_position *pos);
 170 static inline int   zft_tape_at_lbot        (const zft_position *pos);
 171 static inline void  zft_position_before_eof (zft_position *pos,
 172                                              const zft_volinfo *volume);
 173 static 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  */
 181 static 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  */
 196 static 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
 208 static 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  */
 221 static 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 */