git.sur5r.net Git - u-boot/blob - fs/fat/fat_write.c

   1 /*
   2  * fat_write.c
   3  *
   4  * R/W (V)FAT 12/16/32 filesystem implementation by Donggeun Kim
   5  *
   6  * See file CREDITS for list of people who contributed to this
   7  * project.
   8  *
   9  * This program is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU General Public License as
  11  * published by the Free Software Foundation; either version 2 of
  12  * the License, or (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  22  * MA 02111-1307 USA
  23  */
  24
  25 #include <common.h>
  26 #include <command.h>
  27 #include <config.h>
  28 #include <fat.h>
  29 #include <asm/byteorder.h>
  30 #include <part.h>
  31 #include <linux/ctype.h>
  32 #include "fat.c"
  33
  34 static void uppercase(char *str, int len)
  35 {
  36         int i;
  37
  38         for (i = 0; i < len; i++) {
  39                 *str = toupper(*str);
  40                 str++;
  41         }
  42 }
  43
  44 static int total_sector;
  45 static int disk_write(__u32 block, __u32 nr_blocks, void *buf)
  46 {
  47         if (!cur_dev || !cur_dev->block_write)
  48                 return -1;
  49
  50         if (cur_part_info.start + block + nr_blocks >
  51                 cur_part_info.start + total_sector) {
  52                 printf("error: overflow occurs\n");
  53                 return -1;
  54         }
  55
  56         return cur_dev->block_write(cur_dev->dev,
  57                         cur_part_info.start + block, nr_blocks, buf);
  58 }
  59
  60 /*
  61  * Set short name in directory entry
  62  */
  63 static void set_name(dir_entry *dirent, const char *filename)
  64 {
  65         char s_name[VFAT_MAXLEN_BYTES];
  66         char *period;
  67         int period_location, len, i, ext_num;
  68
  69         if (filename == NULL)
  70                 return;
  71
  72         len = strlen(filename);
  73         if (len == 0)
  74                 return;
  75
  76         memcpy(s_name, filename, len);
  77         uppercase(s_name, len);
  78
  79         period = strchr(s_name, '.');
  80         if (period == NULL) {
  81                 period_location = len;
  82                 ext_num = 0;
  83         } else {
  84                 period_location = period - s_name;
  85                 ext_num = len - period_location - 1;
  86         }
  87
  88         /* Pad spaces when the length of file name is shorter than eight */
  89         if (period_location < 8) {
  90                 memcpy(dirent->name, s_name, period_location);
  91                 for (i = period_location; i < 8; i++)
  92                         dirent->name[i] = ' ';
  93         } else if (period_location == 8) {
  94                 memcpy(dirent->name, s_name, period_location);
  95         } else {
  96                 memcpy(dirent->name, s_name, 6);
  97                 dirent->name[6] = '~';
  98                 dirent->name[7] = '1';
  99         }
 100
 101         if (ext_num < 3) {
 102                 memcpy(dirent->ext, s_name + period_location + 1, ext_num);
 103                 for (i = ext_num; i < 3; i++)
 104                         dirent->ext[i] = ' ';
 105         } else
 106                 memcpy(dirent->ext, s_name + period_location + 1, 3);
 107
 108         debug("name : %s\n", dirent->name);
 109         debug("ext : %s\n", dirent->ext);
 110 }
 111
 112 static __u8 num_of_fats;
 113 /*
 114  * Write fat buffer into block device
 115  */
 116 static int flush_fat_buffer(fsdata *mydata)
 117 {
 118         int getsize = FATBUFBLOCKS;
 119         __u32 fatlength = mydata->fatlength;
 120         __u8 *bufptr = mydata->fatbuf;
 121         __u32 startblock = mydata->fatbufnum * FATBUFBLOCKS;
 122
 123         fatlength *= mydata->sect_size;
 124         startblock += mydata->fat_sect;
 125
 126         if (getsize > fatlength)
 127                 getsize = fatlength;
 128
 129         /* Write FAT buf */
 130         if (disk_write(startblock, getsize, bufptr) < 0) {
 131                 debug("error: writing FAT blocks\n");
 132                 return -1;
 133         }
 134
 135         if (num_of_fats == 2) {
 136                 /* Update corresponding second FAT blocks */
 137                 startblock += mydata->fatlength;
 138                 if (disk_write(startblock, getsize, bufptr) < 0) {
 139                         debug("error: writing second FAT blocks\n");
 140                         return -1;
 141                 }
 142         }
 143
 144         return 0;
 145 }
 146
 147 /*
 148  * Get the entry at index 'entry' in a FAT (12/16/32) table.
 149  * On failure 0x00 is returned.
 150  * When bufnum is changed, write back the previous fatbuf to the disk.
 151  */
 152 static __u32 get_fatent_value(fsdata *mydata, __u32 entry)
 153 {
 154         __u32 bufnum;
 155         __u32 off16, offset;
 156         __u32 ret = 0x00;
 157         __u16 val1, val2;
 158
 159         switch (mydata->fatsize) {
 160         case 32:
 161                 bufnum = entry / FAT32BUFSIZE;
 162                 offset = entry - bufnum * FAT32BUFSIZE;
 163                 break;
 164         case 16:
 165                 bufnum = entry / FAT16BUFSIZE;
 166                 offset = entry - bufnum * FAT16BUFSIZE;
 167                 break;
 168         case 12:
 169                 bufnum = entry / FAT12BUFSIZE;
 170                 offset = entry - bufnum * FAT12BUFSIZE;
 171                 break;
 172
 173         default:
 174                 /* Unsupported FAT size */
 175                 return ret;
 176         }
 177
 178         debug("FAT%d: entry: 0x%04x = %d, offset: 0x%04x = %d\n",
 179                mydata->fatsize, entry, entry, offset, offset);
 180
 181         /* Read a new block of FAT entries into the cache. */
 182         if (bufnum != mydata->fatbufnum) {
 183                 int getsize = FATBUFBLOCKS;
 184                 __u8 *bufptr = mydata->fatbuf;
 185                 __u32 fatlength = mydata->fatlength;
 186                 __u32 startblock = bufnum * FATBUFBLOCKS;
 187
 188                 if (getsize > fatlength)
 189                         getsize = fatlength;
 190
 191                 fatlength *= mydata->sect_size; /* We want it in bytes now */
 192                 startblock += mydata->fat_sect; /* Offset from start of disk */
 193
 194                 /* Write back the fatbuf to the disk */
 195                 if (mydata->fatbufnum != -1) {
 196                         if (flush_fat_buffer(mydata) < 0)
 197                                 return -1;
 198                 }
 199
 200                 if (disk_read(startblock, getsize, bufptr) < 0) {
 201                         debug("Error reading FAT blocks\n");
 202                         return ret;
 203                 }
 204                 mydata->fatbufnum = bufnum;
 205         }
 206
 207         /* Get the actual entry from the table */
 208         switch (mydata->fatsize) {
 209         case 32:
 210                 ret = FAT2CPU32(((__u32 *) mydata->fatbuf)[offset]);
 211                 break;
 212         case 16:
 213                 ret = FAT2CPU16(((__u16 *) mydata->fatbuf)[offset]);
 214                 break;
 215         case 12:
 216                 off16 = (offset * 3) / 4;
 217
 218                 switch (offset & 0x3) {
 219                 case 0:
 220                         ret = FAT2CPU16(((__u16 *) mydata->fatbuf)[off16]);
 221                         ret &= 0xfff;
 222                         break;
 223                 case 1:
 224                         val1 = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16]);
 225                         val1 &= 0xf000;
 226                         val2 = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16 + 1]);
 227                         val2 &= 0x00ff;
 228                         ret = (val2 << 4) | (val1 >> 12);
 229                         break;
 230                 case 2:
 231                         val1 = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16]);
 232                         val1 &= 0xff00;
 233                         val2 = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16 + 1]);
 234                         val2 &= 0x000f;
 235                         ret = (val2 << 8) | (val1 >> 8);
 236                         break;
 237                 case 3:
 238                         ret = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16]);
 239                         ret = (ret & 0xfff0) >> 4;
 240                         break;
 241                 default:
 242                         break;
 243                 }
 244                 break;
 245         }
 246         debug("FAT%d: ret: %08x, entry: %08x, offset: %04x\n",
 247                mydata->fatsize, ret, entry, offset);
 248
 249         return ret;
 250 }
 251
 252 /*
 253  * Set the file name information from 'name' into 'slotptr',
 254  */
 255 static int str2slot(dir_slot *slotptr, const char *name, int *idx)
 256 {
 257         int j, end_idx = 0;
 258
 259         for (j = 0; j <= 8; j += 2) {
 260                 if (name[*idx] == 0x00) {
 261                         slotptr->name0_4[j] = 0;
 262                         slotptr->name0_4[j + 1] = 0;
 263                         end_idx++;
 264                         goto name0_4;
 265                 }
 266                 slotptr->name0_4[j] = name[*idx];
 267                 (*idx)++;
 268                 end_idx++;
 269         }
 270         for (j = 0; j <= 10; j += 2) {
 271                 if (name[*idx] == 0x00) {
 272                         slotptr->name5_10[j] = 0;
 273                         slotptr->name5_10[j + 1] = 0;
 274                         end_idx++;
 275                         goto name5_10;
 276                 }
 277                 slotptr->name5_10[j] = name[*idx];
 278                 (*idx)++;
 279                 end_idx++;
 280         }
 281         for (j = 0; j <= 2; j += 2) {
 282                 if (name[*idx] == 0x00) {
 283                         slotptr->name11_12[j] = 0;
 284                         slotptr->name11_12[j + 1] = 0;
 285                         end_idx++;
 286                         goto name11_12;
 287                 }
 288                 slotptr->name11_12[j] = name[*idx];
 289                 (*idx)++;
 290                 end_idx++;
 291         }
 292
 293         if (name[*idx] == 0x00)
 294                 return 1;
 295
 296         return 0;
 297 /* Not used characters are filled with 0xff 0xff */
 298 name0_4:
 299         for (; end_idx < 5; end_idx++) {
 300                 slotptr->name0_4[end_idx * 2] = 0xff;
 301                 slotptr->name0_4[end_idx * 2 + 1] = 0xff;
 302         }
 303         end_idx = 5;
 304 name5_10:
 305         end_idx -= 5;
 306         for (; end_idx < 6; end_idx++) {
 307                 slotptr->name5_10[end_idx * 2] = 0xff;
 308                 slotptr->name5_10[end_idx * 2 + 1] = 0xff;
 309         }
 310         end_idx = 11;
 311 name11_12:
 312         end_idx -= 11;
 313         for (; end_idx < 2; end_idx++) {
 314                 slotptr->name11_12[end_idx * 2] = 0xff;
 315                 slotptr->name11_12[end_idx * 2 + 1] = 0xff;
 316         }
 317
 318         return 1;
 319 }
 320
 321 static int is_next_clust(fsdata *mydata, dir_entry *dentptr);
 322 static void flush_dir_table(fsdata *mydata, dir_entry **dentptr);
 323
 324 /*
 325  * Fill dir_slot entries with appropriate name, id, and attr
 326  * The real directory entry is returned by 'dentptr'
 327  */
 328 static void
 329 fill_dir_slot(fsdata *mydata, dir_entry **dentptr, const char *l_name)
 330 {
 331         dir_slot *slotptr = (dir_slot *)get_contents_vfatname_block;
 332         __u8 counter = 0, checksum;
 333         int idx = 0, ret;
 334         char s_name[16];
 335
 336         /* Get short file name and checksum value */
 337         strncpy(s_name, (*dentptr)->name, 16);
 338         checksum = mkcksum((*dentptr)->name, (*dentptr)->ext);
 339
 340         do {
 341                 memset(slotptr, 0x00, sizeof(dir_slot));
 342                 ret = str2slot(slotptr, l_name, &idx);
 343                 slotptr->id = ++counter;
 344                 slotptr->attr = ATTR_VFAT;
 345                 slotptr->alias_checksum = checksum;
 346                 slotptr++;
 347         } while (ret == 0);
 348
 349         slotptr--;
 350         slotptr->id |= LAST_LONG_ENTRY_MASK;
 351
 352         while (counter >= 1) {
 353                 if (is_next_clust(mydata, *dentptr)) {
 354                         /* A new cluster is allocated for directory table */
 355                         flush_dir_table(mydata, dentptr);
 356                 }
 357                 memcpy(*dentptr, slotptr, sizeof(dir_slot));
 358                 (*dentptr)++;
 359                 slotptr--;
 360                 counter--;
 361         }
 362
 363         if (is_next_clust(mydata, *dentptr)) {
 364                 /* A new cluster is allocated for directory table */
 365                 flush_dir_table(mydata, dentptr);
 366         }
 367 }
 368
 369 static __u32 dir_curclust;
 370
 371 /*
 372  * Extract the full long filename starting at 'retdent' (which is really
 373  * a slot) into 'l_name'. If successful also copy the real directory entry
 374  * into 'retdent'
 375  * If additional adjacent cluster for directory entries is read into memory,
 376  * then 'get_contents_vfatname_block' is copied into 'get_dentfromdir_block' and
 377  * the location of the real directory entry is returned by 'retdent'
 378  * Return 0 on success, -1 otherwise.
 379  */
 380 static int
 381 get_long_file_name(fsdata *mydata, int curclust, __u8 *cluster,
 382               dir_entry **retdent, char *l_name)
 383 {
 384         dir_entry *realdent;
 385         dir_slot *slotptr = (dir_slot *)(*retdent);
 386         dir_slot *slotptr2 = NULL;
 387         __u8 *buflimit = cluster + mydata->sect_size * ((curclust == 0) ?
 388                                                         PREFETCH_BLOCKS :
 389                                                         mydata->clust_size);
 390         __u8 counter = (slotptr->id & ~LAST_LONG_ENTRY_MASK) & 0xff;
 391         int idx = 0, cur_position = 0;
 392
 393         if (counter > VFAT_MAXSEQ) {
 394                 debug("Error: VFAT name is too long\n");
 395                 return -1;
 396         }
 397
 398         while ((__u8 *)slotptr < buflimit) {
 399                 if (counter == 0)
 400                         break;
 401                 if (((slotptr->id & ~LAST_LONG_ENTRY_MASK) & 0xff) != counter)
 402                         return -1;
 403                 slotptr++;
 404                 counter--;
 405         }
 406
 407         if ((__u8 *)slotptr >= buflimit) {
 408                 if (curclust == 0)
 409                         return -1;
 410                 curclust = get_fatent_value(mydata, dir_curclust);
 411                 if (CHECK_CLUST(curclust, mydata->fatsize)) {
 412                         debug("curclust: 0x%x\n", curclust);
 413                         printf("Invalid FAT entry\n");
 414                         return -1;
 415                 }
 416
 417                 dir_curclust = curclust;
 418
 419                 if (get_cluster(mydata, curclust, get_contents_vfatname_block,
 420                                 mydata->clust_size * mydata->sect_size) != 0) {
 421                         debug("Error: reading directory block\n");
 422                         return -1;
 423                 }
 424
 425                 slotptr2 = (dir_slot *)get_contents_vfatname_block;
 426                 while (counter > 0) {
 427                         if (((slotptr2->id & ~LAST_LONG_ENTRY_MASK)
 428                             & 0xff) != counter)
 429                                 return -1;
 430                         slotptr2++;
 431                         counter--;
 432                 }
 433
 434                 /* Save the real directory entry */
 435                 realdent = (dir_entry *)slotptr2;
 436                 while ((__u8 *)slotptr2 > get_contents_vfatname_block) {
 437                         slotptr2--;
 438                         slot2str(slotptr2, l_name, &idx);
 439                 }
 440         } else {
 441                 /* Save the real directory entry */
 442                 realdent = (dir_entry *)slotptr;
 443         }
 444
 445         do {
 446                 slotptr--;
 447                 if (slot2str(slotptr, l_name, &idx))
 448                         break;
 449         } while (!(slotptr->id & LAST_LONG_ENTRY_MASK));
 450
 451         l_name[idx] = '\0';
 452         if (*l_name == DELETED_FLAG)
 453                 *l_name = '\0';
 454         else if (*l_name == aRING)
 455                 *l_name = DELETED_FLAG;
 456         downcase(l_name);
 457
 458         /* Return the real directory entry */
 459         *retdent = realdent;
 460
 461         if (slotptr2) {
 462                 memcpy(get_dentfromdir_block, get_contents_vfatname_block,
 463                         mydata->clust_size * mydata->sect_size);
 464                 cur_position = (__u8 *)realdent - get_contents_vfatname_block;
 465                 *retdent = (dir_entry *) &get_dentfromdir_block[cur_position];
 466         }
 467
 468         return 0;
 469 }
 470
 471 /*
 472  * Set the entry at index 'entry' in a FAT (16/32) table.
 473  */
 474 static int set_fatent_value(fsdata *mydata, __u32 entry, __u32 entry_value)
 475 {
 476         __u32 bufnum, offset;
 477
 478         switch (mydata->fatsize) {
 479         case 32:
 480                 bufnum = entry / FAT32BUFSIZE;
 481                 offset = entry - bufnum * FAT32BUFSIZE;
 482                 break;
 483         case 16:
 484                 bufnum = entry / FAT16BUFSIZE;
 485                 offset = entry - bufnum * FAT16BUFSIZE;
 486                 break;
 487         default:
 488                 /* Unsupported FAT size */
 489                 return -1;
 490         }
 491
 492         /* Read a new block of FAT entries into the cache. */
 493         if (bufnum != mydata->fatbufnum) {
 494                 int getsize = FATBUFBLOCKS;
 495                 __u8 *bufptr = mydata->fatbuf;
 496                 __u32 fatlength = mydata->fatlength;
 497                 __u32 startblock = bufnum * FATBUFBLOCKS;
 498
 499                 fatlength *= mydata->sect_size;
 500                 startblock += mydata->fat_sect;
 501
 502                 if (getsize > fatlength)
 503                         getsize = fatlength;
 504
 505                 if (mydata->fatbufnum != -1) {
 506                         if (flush_fat_buffer(mydata) < 0)
 507                                 return -1;
 508                 }
 509
 510                 if (disk_read(startblock, getsize, bufptr) < 0) {
 511                         debug("Error reading FAT blocks\n");
 512                         return -1;
 513                 }
 514                 mydata->fatbufnum = bufnum;
 515         }
 516
 517         /* Set the actual entry */
 518         switch (mydata->fatsize) {
 519         case 32:
 520                 ((__u32 *) mydata->fatbuf)[offset] = cpu_to_le32(entry_value);
 521                 break;
 522         case 16:
 523                 ((__u16 *) mydata->fatbuf)[offset] = cpu_to_le16(entry_value);
 524                 break;
 525         default:
 526                 return -1;
 527         }
 528
 529         return 0;
 530 }
 531
 532 /*
 533  * Determine the entry value at index 'entry' in a FAT (16/32) table
 534  */
 535 static __u32 determine_fatent(fsdata *mydata, __u32 entry)
 536 {
 537         __u32 next_fat, next_entry = entry + 1;
 538
 539         while (1) {
 540                 next_fat = get_fatent_value(mydata, next_entry);
 541                 if (next_fat == 0) {
 542                         set_fatent_value(mydata, entry, next_entry);
 543                         break;
 544                 }
 545                 next_entry++;
 546         }
 547         debug("FAT%d: entry: %08x, entry_value: %04x\n",
 548                mydata->fatsize, entry, next_entry);
 549
 550         return next_entry;
 551 }
 552
 553 /*
 554  * Write at most 'size' bytes from 'buffer' into the specified cluster.
 555  * Return 0 on success, -1 otherwise.
 556  */
 557 static int
 558 set_cluster(fsdata *mydata, __u32 clustnum, __u8 *buffer,
 559              unsigned long size)
 560 {
 561         int idx = 0;
 562         __u32 startsect;
 563
 564         if (clustnum > 0)
 565                 startsect = mydata->data_begin +
 566                                 clustnum * mydata->clust_size;
 567         else
 568                 startsect = mydata->rootdir_sect;
 569
 570         debug("clustnum: %d, startsect: %d\n", clustnum, startsect);
 571
 572         if (disk_write(startsect, size / mydata->sect_size, buffer) < 0) {
 573                 debug("Error writing data\n");
 574                 return -1;
 575         }
 576
 577         if (size % mydata->sect_size) {
 578                 __u8 tmpbuf[mydata->sect_size];
 579
 580                 idx = size / mydata->sect_size;
 581                 buffer += idx * mydata->sect_size;
 582                 memcpy(tmpbuf, buffer, size % mydata->sect_size);
 583
 584                 if (disk_write(startsect + idx, 1, tmpbuf) < 0) {
 585                         debug("Error writing data\n");
 586                         return -1;
 587                 }
 588
 589                 return 0;
 590         }
 591
 592         return 0;
 593 }
 594
 595 /*
 596  * Find the first empty cluster
 597  */
 598 static int find_empty_cluster(fsdata *mydata)
 599 {
 600         __u32 fat_val, entry = 3;
 601
 602         while (1) {
 603                 fat_val = get_fatent_value(mydata, entry);
 604                 if (fat_val == 0)
 605                         break;
 606                 entry++;
 607         }
 608
 609         return entry;
 610 }
 611
 612 /*
 613  * Write directory entries in 'get_dentfromdir_block' to block device
 614  */
 615 static void flush_dir_table(fsdata *mydata, dir_entry **dentptr)
 616 {
 617         int dir_newclust = 0;
 618
 619         if (set_cluster(mydata, dir_curclust,
 620                     get_dentfromdir_block,
 621                     mydata->clust_size * mydata->sect_size) != 0) {
 622                 printf("error: wrinting directory entry\n");
 623                 return;
 624         }
 625         dir_newclust = find_empty_cluster(mydata);
 626         set_fatent_value(mydata, dir_curclust, dir_newclust);
 627         if (mydata->fatsize == 32)
 628                 set_fatent_value(mydata, dir_newclust, 0xffffff8);
 629         else if (mydata->fatsize == 16)
 630                 set_fatent_value(mydata, dir_newclust, 0xfff8);
 631
 632         dir_curclust = dir_newclust;
 633
 634         if (flush_fat_buffer(mydata) < 0)
 635                 return;
 636
 637         memset(get_dentfromdir_block, 0x00,
 638                 mydata->clust_size * mydata->sect_size);
 639
 640         *dentptr = (dir_entry *) get_dentfromdir_block;
 641 }
 642
 643 /*
 644  * Set empty cluster from 'entry' to the end of a file
 645  */
 646 static int clear_fatent(fsdata *mydata, __u32 entry)
 647 {
 648         __u32 fat_val;
 649
 650         while (1) {
 651                 fat_val = get_fatent_value(mydata, entry);
 652                 if (fat_val != 0)
 653                         set_fatent_value(mydata, entry, 0);
 654                 else
 655                         break;
 656
 657                 if (fat_val == 0xfffffff || fat_val == 0xffff)
 658                         break;
 659
 660                 entry = fat_val;
 661         }
 662
 663         /* Flush fat buffer */
 664         if (flush_fat_buffer(mydata) < 0)
 665                 return -1;
 666
 667         return 0;
 668 }
 669
 670 /*
 671  * Write at most 'maxsize' bytes from 'buffer' into
 672  * the file associated with 'dentptr'
 673  * Return the number of bytes read or -1 on fatal errors.
 674  */
 675 static int
 676 set_contents(fsdata *mydata, dir_entry *dentptr, __u8 *buffer,
 677               unsigned long maxsize)
 678 {
 679         unsigned long filesize = FAT2CPU32(dentptr->size), gotsize = 0;
 680         unsigned int bytesperclust = mydata->clust_size * mydata->sect_size;
 681         __u32 curclust = START(dentptr);
 682         __u32 endclust = 0, newclust = 0;
 683         unsigned long actsize;
 684
 685         debug("Filesize: %ld bytes\n", filesize);
 686
 687         if (maxsize > 0 && filesize > maxsize)
 688                 filesize = maxsize;
 689
 690         debug("%ld bytes\n", filesize);
 691
 692         actsize = bytesperclust;
 693         endclust = curclust;
 694         do {
 695                 /* search for consecutive clusters */
 696                 while (actsize < filesize) {
 697                         newclust = determine_fatent(mydata, endclust);
 698
 699                         if ((newclust - 1) != endclust)
 700                                 goto getit;
 701
 702                         if (CHECK_CLUST(newclust, mydata->fatsize)) {
 703                                 debug("curclust: 0x%x\n", newclust);
 704                                 debug("Invalid FAT entry\n");
 705                                 return gotsize;
 706                         }
 707                         endclust = newclust;
 708                         actsize += bytesperclust;
 709                 }
 710                 /* actsize >= file size */
 711                 actsize -= bytesperclust;
 712                 /* set remaining clusters */
 713                 if (set_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
 714                         debug("error: writing cluster\n");
 715                         return -1;
 716                 }
 717
 718                 /* set remaining bytes */
 719                 gotsize += (int)actsize;
 720                 filesize -= actsize;
 721                 buffer += actsize;
 722                 actsize = filesize;
 723
 724                 if (set_cluster(mydata, endclust, buffer, (int)actsize) != 0) {
 725                         debug("error: writing cluster\n");
 726                         return -1;
 727                 }
 728                 gotsize += actsize;
 729
 730                 /* Mark end of file in FAT */
 731                 if (mydata->fatsize == 16)
 732                         newclust = 0xffff;
 733                 else if (mydata->fatsize == 32)
 734                         newclust = 0xfffffff;
 735                 set_fatent_value(mydata, endclust, newclust);
 736
 737                 return gotsize;
 738 getit:
 739                 if (set_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
 740                         debug("error: writing cluster\n");
 741                         return -1;
 742                 }
 743                 gotsize += (int)actsize;
 744                 filesize -= actsize;
 745                 buffer += actsize;
 746
 747                 if (CHECK_CLUST(curclust, mydata->fatsize)) {
 748                         debug("curclust: 0x%x\n", curclust);
 749                         debug("Invalid FAT entry\n");
 750                         return gotsize;
 751                 }
 752                 actsize = bytesperclust;
 753                 curclust = endclust = newclust;
 754         } while (1);
 755 }
 756
 757 /*
 758  * Fill dir_entry
 759  */
 760 static void fill_dentry(fsdata *mydata, dir_entry *dentptr,
 761         const char *filename, __u32 start_cluster, __u32 size, __u8 attr)
 762 {
 763         if (mydata->fatsize == 32)
 764                 dentptr->starthi =
 765                         cpu_to_le16((start_cluster & 0xffff0000) >> 16);
 766         dentptr->start = cpu_to_le16(start_cluster & 0xffff);
 767         dentptr->size = cpu_to_le32(size);
 768
 769         dentptr->attr = attr;
 770
 771         set_name(dentptr, filename);
 772 }
 773
 774 /*
 775  * Check whether adding a file makes the file system to
 776  * exceed the size of the block device
 777  * Return -1 when overflow occurs, otherwise return 0
 778  */
 779 static int check_overflow(fsdata *mydata, __u32 clustnum, unsigned long size)
 780 {
 781         __u32 startsect, sect_num;
 782
 783         if (clustnum > 0) {
 784                 startsect = mydata->data_begin +
 785                                 clustnum * mydata->clust_size;
 786         } else {
 787                 startsect = mydata->rootdir_sect;
 788         }
 789
 790         sect_num = size / mydata->sect_size;
 791         if (size % mydata->sect_size)
 792                 sect_num++;
 793
 794         if (startsect + sect_num > cur_part_info.start + total_sector)
 795                 return -1;
 796
 797         return 0;
 798 }
 799
 800 /*
 801  * Check if adding several entries exceed one cluster boundary
 802  */
 803 static int is_next_clust(fsdata *mydata, dir_entry *dentptr)
 804 {
 805         int cur_position;
 806
 807         cur_position = (__u8 *)dentptr - get_dentfromdir_block;
 808
 809         if (cur_position >= mydata->clust_size * mydata->sect_size)
 810                 return 1;
 811         else
 812                 return 0;
 813 }
 814
 815 static dir_entry *empty_dentptr;
 816 /*
 817  * Find a directory entry based on filename or start cluster number
 818  * If the directory entry is not found,
 819  * the new position for writing a directory entry will be returned
 820  */
 821 static dir_entry *find_directory_entry(fsdata *mydata, int startsect,
 822         char *filename, dir_entry *retdent, __u32 start)
 823 {
 824         __u32 curclust = (startsect - mydata->data_begin) / mydata->clust_size;
 825
 826         debug("get_dentfromdir: %s\n", filename);
 827
 828         while (1) {
 829                 dir_entry *dentptr;
 830
 831                 int i;
 832
 833                 if (get_cluster(mydata, curclust, get_dentfromdir_block,
 834                             mydata->clust_size * mydata->sect_size) != 0) {
 835                         printf("Error: reading directory block\n");
 836                         return NULL;
 837                 }
 838
 839                 dentptr = (dir_entry *)get_dentfromdir_block;
 840
 841                 dir_curclust = curclust;
 842
 843                 for (i = 0; i < DIRENTSPERCLUST; i++) {
 844                         char s_name[14], l_name[VFAT_MAXLEN_BYTES];
 845
 846                         l_name[0] = '\0';
 847                         if (dentptr->name[0] == DELETED_FLAG) {
 848                                 dentptr++;
 849                                 if (is_next_clust(mydata, dentptr))
 850                                         break;
 851                                 continue;
 852                         }
 853                         if ((dentptr->attr & ATTR_VOLUME)) {
 854                                 if (vfat_enabled &&
 855                                     (dentptr->attr & ATTR_VFAT) &&
 856                                     (dentptr->name[0] & LAST_LONG_ENTRY_MASK)) {
 857                                         get_long_file_name(mydata, curclust,
 858                                                      get_dentfromdir_block,
 859                                                      &dentptr, l_name);
 860                                         debug("vfatname: |%s|\n", l_name);
 861                                 } else {
 862                                         /* Volume label or VFAT entry */
 863                                         dentptr++;
 864                                         if (is_next_clust(mydata, dentptr))
 865                                                 break;
 866                                         continue;
 867                                 }
 868                         }
 869                         if (dentptr->name[0] == 0) {
 870                                 debug("Dentname == NULL - %d\n", i);
 871                                 empty_dentptr = dentptr;
 872                                 return NULL;
 873                         }
 874
 875                         get_name(dentptr, s_name);
 876
 877                         if (strcmp(filename, s_name)
 878                             && strcmp(filename, l_name)) {
 879                                 debug("Mismatch: |%s|%s|\n",
 880                                         s_name, l_name);
 881                                 dentptr++;
 882                                 if (is_next_clust(mydata, dentptr))
 883                                         break;
 884                                 continue;
 885                         }
 886
 887                         memcpy(retdent, dentptr, sizeof(dir_entry));
 888
 889                         debug("DentName: %s", s_name);
 890                         debug(", start: 0x%x", START(dentptr));
 891                         debug(", size:  0x%x %s\n",
 892                               FAT2CPU32(dentptr->size),
 893                               (dentptr->attr & ATTR_DIR) ?
 894                               "(DIR)" : "");
 895
 896                         return dentptr;
 897                 }
 898
 899                 curclust = get_fatent_value(mydata, dir_curclust);
 900                 if ((curclust >= 0xffffff8) || (curclust >= 0xfff8)) {
 901                         empty_dentptr = dentptr;
 902                         return NULL;
 903                 }
 904                 if (CHECK_CLUST(curclust, mydata->fatsize)) {
 905                         debug("curclust: 0x%x\n", curclust);
 906                         debug("Invalid FAT entry\n");
 907                         return NULL;
 908                 }
 909         }
 910
 911         return NULL;
 912 }
 913
 914 static int do_fat_write(const char *filename, void *buffer,
 915         unsigned long size)
 916 {
 917         dir_entry *dentptr, *retdent;
 918         __u32 startsect;
 919         __u32 start_cluster;
 920         boot_sector bs;
 921         volume_info volinfo;
 922         fsdata datablock;
 923         fsdata *mydata = &datablock;
 924         int cursect;
 925         int ret = -1, name_len;
 926         char l_filename[VFAT_MAXLEN_BYTES];
 927         int write_size = size;
 928
 929         dir_curclust = 0;
 930
 931         if (read_bootsectandvi(&bs, &volinfo, &mydata->fatsize)) {
 932                 debug("error: reading boot sector\n");
 933                 return -1;
 934         }
 935
 936         total_sector = bs.total_sect;
 937         if (total_sector == 0)
 938                 total_sector = cur_part_info.size;
 939
 940         if (mydata->fatsize == 32)
 941                 mydata->fatlength = bs.fat32_length;
 942         else
 943                 mydata->fatlength = bs.fat_length;
 944
 945         mydata->fat_sect = bs.reserved;
 946
 947         cursect = mydata->rootdir_sect
 948                 = mydata->fat_sect + mydata->fatlength * bs.fats;
 949         num_of_fats = bs.fats;
 950
 951         mydata->sect_size = (bs.sector_size[1] << 8) + bs.sector_size[0];
 952         mydata->clust_size = bs.cluster_size;
 953
 954         if (mydata->fatsize == 32) {
 955                 mydata->data_begin = mydata->rootdir_sect -
 956                                         (mydata->clust_size * 2);
 957         } else {
 958                 int rootdir_size;
 959
 960                 rootdir_size = ((bs.dir_entries[1]  * (int)256 +
 961                                  bs.dir_entries[0]) *
 962                                  sizeof(dir_entry)) /
 963                                  mydata->sect_size;
 964                 mydata->data_begin = mydata->rootdir_sect +
 965                                         rootdir_size -
 966                                         (mydata->clust_size * 2);
 967         }
 968
 969         mydata->fatbufnum = -1;
 970         mydata->fatbuf = malloc(FATBUFSIZE);
 971         if (mydata->fatbuf == NULL) {
 972                 debug("Error: allocating memory\n");
 973                 return -1;
 974         }
 975
 976         if (disk_read(cursect,
 977                 (mydata->fatsize == 32) ?
 978                 (mydata->clust_size) :
 979                 PREFETCH_BLOCKS, do_fat_read_at_block) < 0) {
 980                 debug("Error: reading rootdir block\n");
 981                 goto exit;
 982         }
 983         dentptr = (dir_entry *) do_fat_read_at_block;
 984
 985         name_len = strlen(filename);
 986         if (name_len >= VFAT_MAXLEN_BYTES)
 987                 name_len = VFAT_MAXLEN_BYTES - 1;
 988
 989         memcpy(l_filename, filename, name_len);
 990         l_filename[name_len] = 0; /* terminate the string */
 991         downcase(l_filename);
 992
 993         startsect = mydata->rootdir_sect;
 994         retdent = find_directory_entry(mydata, startsect,
 995                                 l_filename, dentptr, 0);
 996         if (retdent) {
 997                 /* Update file size and start_cluster in a directory entry */
 998                 retdent->size = cpu_to_le32(size);
 999                 start_cluster = FAT2CPU16(retdent->start);
1000                 if (mydata->fatsize == 32)
1001                         start_cluster |=
1002                                 (FAT2CPU16(retdent->starthi) << 16);
1003
1004                 ret = check_overflow(mydata, start_cluster, size);
1005                 if (ret) {
1006                         printf("Error: %ld overflow\n", size);
1007                         goto exit;
1008                 }
1009
1010                 ret = clear_fatent(mydata, start_cluster);
1011                 if (ret) {
1012                         printf("Error: clearing FAT entries\n");
1013                         goto exit;
1014                 }
1015
1016                 ret = set_contents(mydata, retdent, buffer, size);
1017                 if (ret < 0) {
1018                         printf("Error: writing contents\n");
1019                         goto exit;
1020                 }
1021                 write_size = ret;
1022                 debug("attempt to write 0x%x bytes\n", write_size);
1023
1024                 /* Flush fat buffer */
1025                 ret = flush_fat_buffer(mydata);
1026                 if (ret) {
1027                         printf("Error: flush fat buffer\n");
1028                         goto exit;
1029                 }
1030
1031                 /* Write directory table to device */
1032                 ret = set_cluster(mydata, dir_curclust,
1033                             get_dentfromdir_block,
1034                             mydata->clust_size * mydata->sect_size);
1035                 if (ret) {
1036                         printf("Error: writing directory entry\n");
1037                         goto exit;
1038                 }
1039         } else {
1040                 /* Set short name to set alias checksum field in dir_slot */
1041                 set_name(empty_dentptr, filename);
1042                 fill_dir_slot(mydata, &empty_dentptr, filename);
1043
1044                 ret = start_cluster = find_empty_cluster(mydata);
1045                 if (ret < 0) {
1046                         printf("Error: finding empty cluster\n");
1047                         goto exit;
1048                 }
1049
1050                 ret = check_overflow(mydata, start_cluster, size);
1051                 if (ret) {
1052                         printf("Error: %ld overflow\n", size);
1053                         goto exit;
1054                 }
1055
1056                 /* Set attribute as archieve for regular file */
1057                 fill_dentry(mydata, empty_dentptr, filename,
1058                         start_cluster, size, 0x20);
1059
1060                 ret = set_contents(mydata, empty_dentptr, buffer, size);
1061                 if (ret < 0) {
1062                         printf("Error: writing contents\n");
1063                         goto exit;
1064                 }
1065                 write_size = ret;
1066                 debug("attempt to write 0x%x bytes\n", write_size);
1067
1068                 /* Flush fat buffer */
1069                 ret = flush_fat_buffer(mydata);
1070                 if (ret) {
1071                         printf("Error: flush fat buffer\n");
1072                         goto exit;
1073                 }
1074
1075                 /* Write directory table to device */
1076                 ret = set_cluster(mydata, dir_curclust,
1077                             get_dentfromdir_block,
1078                             mydata->clust_size * mydata->sect_size);
1079                 if (ret) {
1080                         printf("Error: writing directory entry\n");
1081                         goto exit;
1082                 }
1083         }
1084
1085 exit:
1086         free(mydata->fatbuf);
1087         return ret < 0 ? ret : write_size;
1088 }
1089
1090 int file_fat_write(const char *filename, void *buffer, unsigned long maxsize)
1091 {
1092         printf("writing %s\n", filename);
1093         return do_fat_write(filename, buffer, maxsize);
1094 }