vtoycli/fat_io_lib/release/fat_write.c

   1 //-----------------------------------------------------------------------------
   2 //-----------------------------------------------------------------------------
   3 //                            FAT16/32 File IO Library
   4 //                                    V2.6
   5 //                              Ultra-Embedded.com
   6 //                            Copyright 2003 - 2012
   7 //
   8 //                         Email: admin@ultra-embedded.com
   9 //
  10 //                                License: GPL
  11 //   If you would like a version with a more permissive license for use in
  12 //   closed source commercial applications please contact me for details.
  13 //-----------------------------------------------------------------------------
  14 //
  15 // This file is part of FAT File IO Library.
  16 //
  17 // FAT File IO Library is free software; you can redistribute it and/or modify
  18 // it under the terms of the GNU General Public License as published by
  19 // the Free Software Foundation; either version 2 of the License, or
  20 // (at your option) any later version.
  21 //
  22 // FAT File IO Library is distributed in the hope that it will be useful,
  23 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  24 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  25 // GNU General Public License for more details.
  26 //
  27 // You should have received a copy of the GNU General Public License
  28 // along with FAT File IO Library; if not, write to the Free Software
  29 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  30 //-----------------------------------------------------------------------------
  31 //-----------------------------------------------------------------------------
  32 #include <string.h>
  33 #include "fat_defs.h"
  34 #include "fat_access.h"
  35 #include "fat_table.h"
  36 #include "fat_write.h"
  37 #include "fat_string.h"
  38 #include "fat_misc.h"
  39
  40 #if FATFS_INC_WRITE_SUPPORT
  41 //-----------------------------------------------------------------------------
  42 // fatfs_add_free_space: Allocate another cluster of free space to the end
  43 // of a files cluster chain.
  44 //-----------------------------------------------------------------------------
  45 int fatfs_add_free_space(struct fatfs *fs, uint32 *startCluster, uint32 clusters)
  46 {
  47     uint32 i;
  48     uint32 nextcluster;
  49     uint32 start = *startCluster;
  50
  51     // Set the next free cluster hint to unknown
  52     if (fs->next_free_cluster != FAT32_LAST_CLUSTER)
  53         fatfs_set_fs_info_next_free_cluster(fs, FAT32_LAST_CLUSTER);
  54
  55     for (i=0;i<clusters;i++)
  56     {
  57         // Start looking for free clusters from the beginning
  58         if (fatfs_find_blank_cluster(fs, fs->rootdir_first_cluster, &nextcluster))
  59         {
  60             // Point last to this
  61             fatfs_fat_set_cluster(fs, start, nextcluster);
  62
  63             // Point this to end of file
  64             fatfs_fat_set_cluster(fs, nextcluster, FAT32_LAST_CLUSTER);
  65
  66             // Adjust argument reference
  67             start = nextcluster;
  68             if (i == 0)
  69                 *startCluster = nextcluster;
  70         }
  71         else
  72             return 0;
  73     }
  74
  75     return 1;
  76 }
  77 //-----------------------------------------------------------------------------
  78 // fatfs_allocate_free_space: Add an ammount of free space to a file either from
  79 // 'startCluster' if newFile = false, or allocating a new start to the chain if
  80 // newFile = true.
  81 //-----------------------------------------------------------------------------
  82 int fatfs_allocate_free_space(struct fatfs *fs, int newFile, uint32 *startCluster, uint32 size)
  83 {
  84     uint32 clusterSize;
  85     uint32 clusterCount;
  86     uint32 nextcluster;
  87
  88     if (size==0)
  89         return 0;
  90
  91     // Set the next free cluster hint to unknown
  92     if (fs->next_free_cluster != FAT32_LAST_CLUSTER)
  93         fatfs_set_fs_info_next_free_cluster(fs, FAT32_LAST_CLUSTER);
  94
  95     // Work out size and clusters
  96     clusterSize = fs->sectors_per_cluster * FAT_SECTOR_SIZE;
  97     clusterCount = (size / clusterSize);
  98
  99     // If any left over
 100     if (size-(clusterSize*clusterCount))
 101         clusterCount++;
 102
 103     // Allocated first link in the chain if a new file
 104     if (newFile)
 105     {
 106         if (!fatfs_find_blank_cluster(fs, fs->rootdir_first_cluster, &nextcluster))
 107             return 0;
 108
 109         // If this is all that is needed then all done
 110         if (clusterCount==1)
 111         {
 112             fatfs_fat_set_cluster(fs, nextcluster, FAT32_LAST_CLUSTER);
 113             *startCluster = nextcluster;
 114             return 1;
 115         }
 116     }
 117     // Allocate from end of current chain (startCluster is end of chain)
 118     else
 119         nextcluster = *startCluster;
 120
 121     if (!fatfs_add_free_space(fs, &nextcluster, clusterCount))
 122             return 0;
 123
 124     return 1;
 125 }
 126 //-----------------------------------------------------------------------------
 127 // fatfs_find_free_dir_offset: Find a free space in the directory for a new entry
 128 // which takes up 'entryCount' blocks (or allocate some more)
 129 //-----------------------------------------------------------------------------
 130 static int fatfs_find_free_dir_offset(struct fatfs *fs, uint32 dirCluster, int entryCount, uint32 *pSector, uint8 *pOffset)
 131 {
 132     struct fat_dir_entry *directoryEntry;
 133     uint8 item=0;
 134     uint16 recordoffset = 0;
 135     uint8 i=0;
 136     int x=0;
 137     int possible_spaces = 0;
 138     int start_recorded = 0;
 139
 140     // No entries required?
 141     if (entryCount == 0)
 142         return 0;
 143
 144     // Main cluster following loop
 145     while (1)
 146     {
 147         // Read sector
 148         if (fatfs_sector_reader(fs, dirCluster, x++, 0))
 149         {
 150             // Analyse Sector
 151             for (item = 0; item < FAT_DIR_ENTRIES_PER_SECTOR; item++)
 152             {
 153                 // Create the multiplier for sector access
 154                 recordoffset = FAT_DIR_ENTRY_SIZE * item;
 155
 156                 // Overlay directory entry over buffer
 157                 directoryEntry = (struct fat_dir_entry*)(fs->currentsector.sector+recordoffset);
 158
 159                 // LFN Entry
 160                 if (fatfs_entry_lfn_text(directoryEntry))
 161                 {
 162                     // First entry?
 163                     if (possible_spaces == 0)
 164                     {
 165                         // Store start
 166                         *pSector = x-1;
 167                         *pOffset = item;
 168                         start_recorded = 1;
 169                     }
 170
 171                     // Increment the count in-case the file turns
 172                     // out to be deleted...
 173                     possible_spaces++;
 174                 }
 175                 // SFN Entry
 176                 else
 177                 {
 178                     // Has file been deleted?
 179                     if (fs->currentsector.sector[recordoffset] == FILE_HEADER_DELETED)
 180                     {
 181                         // First entry?
 182                         if (possible_spaces == 0)
 183                         {
 184                             // Store start
 185                             *pSector = x-1;
 186                             *pOffset = item;
 187                             start_recorded = 1;
 188                         }
 189
 190                         possible_spaces++;
 191
 192                         // We have found enough space?
 193                         if (possible_spaces >= entryCount)
 194                             return 1;
 195
 196                         // Else continue counting until we find a valid entry!
 197                     }
 198                     // Is the file entry empty?
 199                     else if (fs->currentsector.sector[recordoffset] == FILE_HEADER_BLANK)
 200                     {
 201                         // First entry?
 202                         if (possible_spaces == 0)
 203                         {
 204                             // Store start
 205                             *pSector = x-1;
 206                             *pOffset = item;
 207                             start_recorded = 1;
 208                         }
 209
 210                         // Increment the blank entries count
 211                         possible_spaces++;
 212
 213                         // We have found enough space?
 214                         if (possible_spaces >= entryCount)
 215                             return 1;
 216                     }
 217                     // File entry is valid
 218                     else
 219                     {
 220                         // Reset all flags
 221                         possible_spaces = 0;
 222                         start_recorded = 0;
 223                     }
 224                 }
 225             } // End of for
 226         } // End of if
 227         // Run out of free space in the directory, allocate some more
 228         else
 229         {
 230             uint32 newCluster;
 231
 232             // Get a new cluster for directory
 233             if (!fatfs_find_blank_cluster(fs, fs->rootdir_first_cluster, &newCluster))
 234                 return 0;
 235
 236             // Add cluster to end of directory tree
 237             if (!fatfs_fat_add_cluster_to_chain(fs, dirCluster, newCluster))
 238                 return 0;
 239
 240             // Erase new directory cluster
 241             memset(fs->currentsector.sector, 0x00, FAT_SECTOR_SIZE);
 242             for (i=0;i<fs->sectors_per_cluster;i++)
 243             {
 244                 if (!fatfs_write_sector(fs, newCluster, i, 0))
 245                     return 0;
 246             }
 247
 248             // If non of the name fitted on previous sectors
 249             if (!start_recorded)
 250             {
 251                 // Store start
 252                 *pSector = (x-1);
 253                 *pOffset = 0;
 254                 start_recorded = 1;
 255             }
 256
 257             return 1;
 258         }
 259     } // End of while loop
 260
 261     return 0;
 262 }
 263 //-----------------------------------------------------------------------------
 264 // fatfs_add_file_entry: Add a directory entry to a location found by FindFreeOffset
 265 //-----------------------------------------------------------------------------
 266 int fatfs_add_file_entry(struct fatfs *fs, uint32 dirCluster, char *filename, char *shortfilename, uint32 startCluster, uint32 size, int dir)
 267 {
 268     uint8 item=0;
 269     uint16 recordoffset = 0;
 270     uint8 i=0;
 271     uint32 x=0;
 272     int entryCount;
 273     struct fat_dir_entry shortEntry;
 274     int dirtySector = 0;
 275
 276     uint32 dirSector = 0;
 277     uint8 dirOffset = 0;
 278     int foundEnd = 0;
 279
 280     uint8 checksum;
 281     uint8 *pSname;
 282
 283     // No write access?
 284     if (!fs->disk_io.write_media)
 285         return 0;
 286
 287 #if FATFS_INC_LFN_SUPPORT
 288     // How many LFN entries are required?
 289     // NOTE: We always request one LFN even if it would fit in a SFN!
 290     entryCount = fatfs_lfn_entries_required(filename);
 291     if (!entryCount)
 292         return 0;
 293 #else
 294     entryCount = 0;
 295 #endif
 296
 297     // Find space in the directory for this filename (or allocate some more)
 298     // NOTE: We need to find space for at least the LFN + SFN (or just the SFN if LFNs not supported).
 299     if (!fatfs_find_free_dir_offset(fs, dirCluster, entryCount + 1, &dirSector, &dirOffset))
 300         return 0;
 301
 302     // Generate checksum of short filename
 303     pSname = (uint8*)shortfilename;
 304     checksum = 0;
 305     for (i=11; i!=0; i--) checksum = ((checksum & 1) ? 0x80 : 0) + (checksum >> 1) + *pSname++;
 306
 307     // Start from current sector where space was found!
 308     x = dirSector;
 309
 310     // Main cluster following loop
 311     while (1)
 312     {
 313         // Read sector
 314         if (fatfs_sector_reader(fs, dirCluster, x++, 0))
 315         {
 316             // Analyse Sector
 317             for (item = 0; item < FAT_DIR_ENTRIES_PER_SECTOR; item++)
 318             {
 319                 // Create the multiplier for sector access
 320                 recordoffset = FAT_DIR_ENTRY_SIZE * item;
 321
 322                 // If the start position for the entry has been found
 323                 if (foundEnd==0)
 324                     if ( (dirSector==(x-1)) && (dirOffset==item) )
 325                         foundEnd = 1;
 326
 327                 // Start adding filename
 328                 if (foundEnd)
 329                 {
 330                     if (entryCount==0)
 331                     {
 332                         // Short filename
 333                         fatfs_sfn_create_entry(shortfilename, size, startCluster, &shortEntry, dir);
 334
 335 #if FATFS_INC_TIME_DATE_SUPPORT
 336                         // Update create, access & modify time & date
 337                         fatfs_update_timestamps(&shortEntry, 1, 1, 1);
 338 #endif
 339
 340                         memcpy(&fs->currentsector.sector[recordoffset], &shortEntry, sizeof(shortEntry));
 341
 342                         // Writeback
 343                         return fs->disk_io.write_media(fs->currentsector.address, fs->currentsector.sector, 1);
 344                     }
 345 #if FATFS_INC_LFN_SUPPORT
 346                     else
 347                     {
 348                         entryCount--;
 349
 350                         // Copy entry to directory buffer
 351                         fatfs_filename_to_lfn(filename, &fs->currentsector.sector[recordoffset], entryCount, checksum);
 352                         dirtySector = 1;
 353                     }
 354 #endif
 355                 }
 356             } // End of if
 357
 358             // Write back to disk before loading another sector
 359             if (dirtySector)
 360             {
 361                 if (!fs->disk_io.write_media(fs->currentsector.address, fs->currentsector.sector, 1))
 362                     return 0;
 363
 364                 dirtySector = 0;
 365             }
 366         }
 367         else
 368             return 0;
 369     } // End of while loop
 370
 371     return 0;
 372 }
 373 #endif