workbench/fs/fat/fat_fs.h

   1 /*
   2  * fat.handler - FAT12/16/32 filesystem handler
   3  *
   4  * Copyright © 2006 Marek Szyprowski
   5  * Copyright © 2007 The AROS Development Team
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the same terms as AROS itself.
   9  *
  10  * $Id$
  11  */
  12
  13 #ifndef FAT_HANDLER_H
  14 #define FAT_HANDLER_H
  15
  16 #define DEBUG_DIRENTRY      0
  17 #define DEBUG_FILE          0
  18 #define DEBUG_DUMP          0
  19 #define DEBUG_LOCK          0
  20 #define DEBUG_NAMES         0
  21 #define DEBUG_NOTIFY        0
  22 #define DEBUG_OPS           0
  23 #define DEBUG_PACKETS       0
  24 #define DEBUG_CACHESTATS    0
  25 #define DEBUG_MISC          0
  26
  27 #include <aros/libcall.h>
  28 #include <devices/trackdisk.h>
  29
  30 #include "fat_struct.h"
  31
  32 #include "cache.h"
  33
  34 /* filesystem structures */
  35
  36 #define ID_FAT_DISK 0x46415400UL
  37
  38 #define ID_FAT12_DISK 0x46415400UL
  39 #define ID_FAT16_DISK 0x46415401UL
  40 #define ID_FAT32_DISK 0x46415402UL
  41
  42 #define ACTION_VOLUME_ADD 16000
  43 #define ACTION_VOLUME_REMOVE 16001
  44
  45 extern struct Globals *glob;
  46
  47 #define DEF_POOL_SIZE 65536
  48 #define DEF_POOL_THRESHOLD DEF_POOL_SIZE
  49 #define DEF_BUFF_LINES 128
  50 #define DEF_READ_AHEAD 16*1024
  51
  52
  53 /* a handle on something, file or directory */
  54 struct IOHandle {
  55     struct FSSuper      *sb;            /* filesystem data */
  56
  57     ULONG               first_cluster;  /* first cluster of this file */
  58     ULONG               cur_cluster;    /* cluster that the current sector is within */
  59
  60     ULONG               cluster_offset; /* cluster number of this cluster within the current file */
  61
  62     ULONG               first_sector;   /* first sector in the first cluster, for fat12/16 root dir */
  63     ULONG               cur_sector;     /* sector number our block is currently in */
  64
  65     ULONG               sector_offset;  /* current sector as an offset in the current cluster
  66                                            ie cur = sector(cur_cluster) + offset */
  67
  68     struct cache_block  *block;         /* current block from the cache */
  69 };
  70
  71 /* a handle on a directory */
  72 struct DirHandle {
  73     struct IOHandle     ioh;
  74
  75     ULONG               cur_index;      /* last entry returned, for GetNextDirEntry */
  76 };
  77
  78 /* single directory entry */
  79 struct DirEntry {
  80     struct FSSuper      *sb;            /* filesystem data */
  81
  82     ULONG               cluster;        /* cluster the containing directory starts at */
  83     ULONG               index;          /* index of this entry */
  84
  85     ULONG               pos;            /* byte offset within directory that the entry came from */
  86
  87     union {
  88         struct FATDirEntry      entry;
  89         struct FATLongDirEntry  long_entry;
  90     } e;
  91 };
  92
  93 #define FAT_ROOTDIR_MARK    0xFFFFFFFFlu
  94
  95 struct GlobalLock;
  96
  97 struct ExtFileLock {
  98     /* struct FileLock */
  99     BPTR                fl_Link;
 100     LONG                fl_Key;
 101     LONG                fl_Access;
 102     struct MsgPort *    fl_Task;
 103     BPTR                fl_Volume;
 104
 105     ULONG               magic;          /* we set this to ID_FAT_DISK so we can tell
 106                                            our locks from those of other filesystems */
 107
 108     struct MinNode      node;           /* node in the list of locks attached to the global lock */
 109     struct GlobalLock   *gl;            /* pointer to the global lock for this file */
 110
 111     struct IOHandle     ioh;            /* handle for reads and writes */
 112     ULONG               pos;            /* current seek position within the file */
 113
 114     BOOL                do_notify;      /* if set, send notification on file close (ACTION_END) */
 115 };
 116
 117 struct GlobalLock {
 118     struct MinNode      node;
 119
 120     ULONG               dir_cluster;    /* first cluster of the directory we're in */
 121     ULONG               dir_entry;      /* this is our dir entry within dir_cluster */
 122
 123     LONG                access;         /* access mode, shared or exclusive */
 124
 125     ULONG               first_cluster;  /* first data cluster */
 126
 127     ULONG               attr;           /* file attributes, from the dir entry */
 128     ULONG               size;           /* file size, from the dir entry */
 129
 130     UBYTE               name[108];      /* copy of the name (bstr) */
 131
 132     struct MinList      locks;          /* list of ExtFileLocks opened on this file */
 133 };
 134
 135 /* a node in the list of notification requests */
 136 struct NotifyNode {
 137     struct MinNode          node;
 138
 139     struct GlobalLock       *gl;        /* pointer to global lock if this file is
 140                                            locked. if its not, this is NULL */
 141
 142     struct NotifyRequest    *nr;        /* the request that DOS passed us */
 143 };
 144
 145 struct VolumeInfo {
 146     UBYTE               name[32];     /* BCPL string */
 147     struct DateStamp    create_time;
 148 };
 149
 150 struct FSSuper {
 151     struct FSSuper *next;
 152     struct DosList *doslist;
 153
 154     struct cache *cache;
 155     ULONG        first_device_sector;
 156
 157     ULONG sectorsize;
 158     ULONG sectorsize_bits;
 159
 160     ULONG cluster_sectors;
 161     ULONG clustersize;
 162     ULONG clustersize_bits;
 163     ULONG cluster_sectors_bits;
 164
 165     ULONG first_fat_sector;
 166     ULONG first_data_sector;
 167     ULONG first_rootdir_sector;
 168
 169     ULONG rootdir_sectors;
 170     ULONG total_sectors;
 171     ULONG data_sectors;
 172     ULONG clusters_count;
 173     ULONG fat_size;
 174
 175     ULONG free_clusters;
 176
 177     ULONG volume_id;
 178     ULONG type;
 179     ULONG eoc_mark;
 180
 181     struct cache_block  **fat_blocks;
 182     ULONG               fat_blocks_count;
 183
 184     ULONG fat_cachesize;
 185     ULONG fat_cachesize_bits;
 186     ULONG fat_cache_block;
 187
 188     ULONG rootdir_cluster;
 189     ULONG rootdir_sector;
 190
 191     struct VolumeInfo volume;
 192
 193     struct MinList locks;
 194     struct GlobalLock root_lock;
 195
 196     struct MinList notifies;
 197
 198     /* function table */
 199     ULONG (*func_get_fat_entry)(struct FSSuper *sb, ULONG n);
 200     void  (*func_set_fat_entry)(struct FSSuper *sb, ULONG n, ULONG val);
 201     /* ... */
 202 };
 203
 204 struct Globals {
 205     /* mem/task */
 206     struct Task *ourtask;
 207     struct MsgPort *ourport;
 208     APTR mempool;
 209
 210     struct MsgPort *notifyport;
 211
 212     /* fs */
 213     struct DosList *devnode;
 214     struct FileSysStartupMsg *fssm;
 215     LONG quit;
 216     BOOL autodetect;
 217
 218     /* io */
 219     struct IOExtTD *diskioreq;
 220     struct IOExtTD *diskchgreq;
 221     struct MsgPort *diskport;
 222
 223     /* volumes */
 224     struct FSSuper *sb;    /* current sb */
 225     struct FSSuper *sblist;   /* list of sbs with outstanding locks */
 226
 227     /* disk status */
 228     LONG disk_inserted;
 229     LONG disk_inhibited;
 230 };
 231
 232 #include "support.h"
 233
 234 /* new definitions as we refactor the code */
 235
 236 /* get the first sector of a cluster */
 237 #define SECTOR_FROM_CLUSTER(sb,cl) ((ULONG) (((cl-2) << sb->cluster_sectors_bits) + sb->first_data_sector))
 238
 239 #define FIRST_FILE_CLUSTER(de)                                       \
 240     (AROS_LE2WORD((de)->e.entry.first_cluster_lo) |                  \
 241      (((ULONG) AROS_LE2WORD((de)->e.entry.first_cluster_hi)) << 16))
 242
 243 #define RESET_HANDLE(ioh)                                          \
 244     do {                                                           \
 245         (ioh)->cluster_offset = (ioh)->sector_offset = 0xffffffff; \
 246         if ((ioh)->block != NULL) {                                \
 247             cache_put_block((ioh)->sb->cache, (ioh)->block, 0);    \
 248             (ioh)->block = NULL;                                   \
 249         }                                                          \
 250     } while (0);
 251
 252 #define GET_NEXT_CLUSTER(sb,cl)     (sb->func_get_fat_entry(sb,cl))
 253 #define SET_NEXT_CLUSTER(sb,cl,val) (sb->func_set_fat_entry(sb,cl,val))
 254
 255 #define CALC_SHORT_NAME_CHECKSUM(name,checksum)                                 \
 256     do {                                                                        \
 257         ULONG i;                                                                \
 258         checksum = 0;                                                           \
 259         for (i = 0; i < 11; i++)                                                \
 260             checksum = ((checksum & 1) ? 0x80 : 0) + (checksum >> 1) + name[i]; \
 261     } while(0);
 262
 263 #endif