fs/fat/fat_write.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * fat_write.c
   4  *
   5  * R/W (V)FAT 12/16/32 filesystem implementation by Donggeun Kim
   6  */
   7
   8 #include <common.h>
   9 #include <command.h>
  10 #include <config.h>
  11 #include <fat.h>
  12 #include <malloc.h>
  13 #include <asm/byteorder.h>
  14 #include <part.h>
  15 #include <linux/ctype.h>
  16 #include <div64.h>
  17 #include <linux/math64.h>
  18 #include "fat.c"
  19
  20 static void uppercase(char *str, int len)
  21 {
  22         int i;
  23
  24         for (i = 0; i < len; i++) {
  25                 *str = toupper(*str);
  26                 str++;
  27         }
  28 }
  29
  30 static int total_sector;
  31 static int disk_write(__u32 block, __u32 nr_blocks, void *buf)
  32 {
  33         ulong ret;
  34
  35         if (!cur_dev)
  36                 return -1;
  37
  38         if (cur_part_info.start + block + nr_blocks >
  39                 cur_part_info.start + total_sector) {
  40                 printf("error: overflow occurs\n");
  41                 return -1;
  42         }
  43
  44         ret = blk_dwrite(cur_dev, cur_part_info.start + block, nr_blocks, buf);
  45         if (nr_blocks && ret == 0)
  46                 return -1;
  47
  48         return ret;
  49 }
  50
  51 /*
  52  * Set short name in directory entry
  53  */
  54 static void set_name(dir_entry *dirent, const char *filename)
  55 {
  56         char s_name[VFAT_MAXLEN_BYTES];
  57         char *period;
  58         int period_location, len, i, ext_num;
  59
  60         if (filename == NULL)
  61                 return;
  62
  63         len = strlen(filename);
  64         if (len == 0)
  65                 return;
  66
  67         strcpy(s_name, filename);
  68         uppercase(s_name, len);
  69
  70         period = strchr(s_name, '.');
  71         if (period == NULL) {
  72                 period_location = len;
  73                 ext_num = 0;
  74         } else {
  75                 period_location = period - s_name;
  76                 ext_num = len - period_location - 1;
  77         }
  78
  79         /* Pad spaces when the length of file name is shorter than eight */
  80         if (period_location < 8) {
  81                 memcpy(dirent->name, s_name, period_location);
  82                 for (i = period_location; i < 8; i++)
  83                         dirent->name[i] = ' ';
  84         } else if (period_location == 8) {
  85                 memcpy(dirent->name, s_name, period_location);
  86         } else {
  87                 memcpy(dirent->name, s_name, 6);
  88                 dirent->name[6] = '~';
  89                 dirent->name[7] = '1';
  90         }
  91
  92         if (ext_num < 3) {
  93                 memcpy(dirent->ext, s_name + period_location + 1, ext_num);
  94                 for (i = ext_num; i < 3; i++)
  95                         dirent->ext[i] = ' ';
  96         } else
  97                 memcpy(dirent->ext, s_name + period_location + 1, 3);
  98
  99         debug("name : %s\n", dirent->name);
 100         debug("ext : %s\n", dirent->ext);
 101 }
 102
 103 /*
 104  * Write fat buffer into block device
 105  */
 106 static int flush_dirty_fat_buffer(fsdata *mydata)
 107 {
 108         int getsize = FATBUFBLOCKS;
 109         __u32 fatlength = mydata->fatlength;
 110         __u8 *bufptr = mydata->fatbuf;
 111         __u32 startblock = mydata->fatbufnum * FATBUFBLOCKS;
 112
 113         debug("debug: evicting %d, dirty: %d\n", mydata->fatbufnum,
 114               (int)mydata->fat_dirty);
 115
 116         if ((!mydata->fat_dirty) || (mydata->fatbufnum == -1))
 117                 return 0;
 118
 119         /* Cap length if fatlength is not a multiple of FATBUFBLOCKS */
 120         if (startblock + getsize > fatlength)
 121                 getsize = fatlength - startblock;
 122
 123         startblock += mydata->fat_sect;
 124
 125         /* Write FAT buf */
 126         if (disk_write(startblock, getsize, bufptr) < 0) {
 127                 debug("error: writing FAT blocks\n");
 128                 return -1;
 129         }
 130
 131         if (mydata->fats == 2) {
 132                 /* Update corresponding second FAT blocks */
 133                 startblock += mydata->fatlength;
 134                 if (disk_write(startblock, getsize, bufptr) < 0) {
 135                         debug("error: writing second FAT blocks\n");
 136                         return -1;
 137                 }
 138         }
 139         mydata->fat_dirty = 0;
 140
 141         return 0;
 142 }
 143
 144 /*
 145  * Set the file name information from 'name' into 'slotptr',
 146  */
 147 static int str2slot(dir_slot *slotptr, const char *name, int *idx)
 148 {
 149         int j, end_idx = 0;
 150
 151         for (j = 0; j <= 8; j += 2) {
 152                 if (name[*idx] == 0x00) {
 153                         slotptr->name0_4[j] = 0;
 154                         slotptr->name0_4[j + 1] = 0;
 155                         end_idx++;
 156                         goto name0_4;
 157                 }
 158                 slotptr->name0_4[j] = name[*idx];
 159                 (*idx)++;
 160                 end_idx++;
 161         }
 162         for (j = 0; j <= 10; j += 2) {
 163                 if (name[*idx] == 0x00) {
 164                         slotptr->name5_10[j] = 0;
 165                         slotptr->name5_10[j + 1] = 0;
 166                         end_idx++;
 167                         goto name5_10;
 168                 }
 169                 slotptr->name5_10[j] = name[*idx];
 170                 (*idx)++;
 171                 end_idx++;
 172         }
 173         for (j = 0; j <= 2; j += 2) {
 174                 if (name[*idx] == 0x00) {
 175                         slotptr->name11_12[j] = 0;
 176                         slotptr->name11_12[j + 1] = 0;
 177                         end_idx++;
 178                         goto name11_12;
 179                 }
 180                 slotptr->name11_12[j] = name[*idx];
 181                 (*idx)++;
 182                 end_idx++;
 183         }
 184
 185         if (name[*idx] == 0x00)
 186                 return 1;
 187
 188         return 0;
 189 /* Not used characters are filled with 0xff 0xff */
 190 name0_4:
 191         for (; end_idx < 5; end_idx++) {
 192                 slotptr->name0_4[end_idx * 2] = 0xff;
 193                 slotptr->name0_4[end_idx * 2 + 1] = 0xff;
 194         }
 195         end_idx = 5;
 196 name5_10:
 197         end_idx -= 5;
 198         for (; end_idx < 6; end_idx++) {
 199                 slotptr->name5_10[end_idx * 2] = 0xff;
 200                 slotptr->name5_10[end_idx * 2 + 1] = 0xff;
 201         }
 202         end_idx = 11;
 203 name11_12:
 204         end_idx -= 11;
 205         for (; end_idx < 2; end_idx++) {
 206                 slotptr->name11_12[end_idx * 2] = 0xff;
 207                 slotptr->name11_12[end_idx * 2 + 1] = 0xff;
 208         }
 209
 210         return 1;
 211 }
 212
 213 static int new_dir_table(fat_itr *itr);
 214 static int flush_dir(fat_itr *itr);
 215
 216 /*
 217  * Fill dir_slot entries with appropriate name, id, and attr
 218  * 'itr' will point to a next entry
 219  */
 220 static int
 221 fill_dir_slot(fat_itr *itr, const char *l_name)
 222 {
 223         __u8 temp_dir_slot_buffer[MAX_LFN_SLOT * sizeof(dir_slot)];
 224         dir_slot *slotptr = (dir_slot *)temp_dir_slot_buffer;
 225         __u8 counter = 0, checksum;
 226         int idx = 0, ret;
 227
 228         /* Get short file name checksum value */
 229         checksum = mkcksum(itr->dent->name, itr->dent->ext);
 230
 231         do {
 232                 memset(slotptr, 0x00, sizeof(dir_slot));
 233                 ret = str2slot(slotptr, l_name, &idx);
 234                 slotptr->id = ++counter;
 235                 slotptr->attr = ATTR_VFAT;
 236                 slotptr->alias_checksum = checksum;
 237                 slotptr++;
 238         } while (ret == 0);
 239
 240         slotptr--;
 241         slotptr->id |= LAST_LONG_ENTRY_MASK;
 242
 243         while (counter >= 1) {
 244                 memcpy(itr->dent, slotptr, sizeof(dir_slot));
 245                 slotptr--;
 246                 counter--;
 247
 248                 if (itr->remaining == 0)
 249                         flush_dir(itr);
 250
 251                 /* allocate a cluster for more entries */
 252                 if (!fat_itr_next(itr))
 253                         if (!itr->dent &&
 254                             (!itr->is_root || itr->fsdata->fatsize == 32) &&
 255                             new_dir_table(itr))
 256                                 return -1;
 257         }
 258
 259         return 0;
 260 }
 261
 262 /*
 263  * Set the entry at index 'entry' in a FAT (12/16/32) table.
 264  */
 265 static int set_fatent_value(fsdata *mydata, __u32 entry, __u32 entry_value)
 266 {
 267         __u32 bufnum, offset, off16;
 268         __u16 val1, val2;
 269
 270         switch (mydata->fatsize) {
 271         case 32:
 272                 bufnum = entry / FAT32BUFSIZE;
 273                 offset = entry - bufnum * FAT32BUFSIZE;
 274                 break;
 275         case 16:
 276                 bufnum = entry / FAT16BUFSIZE;
 277                 offset = entry - bufnum * FAT16BUFSIZE;
 278                 break;
 279         case 12:
 280                 bufnum = entry / FAT12BUFSIZE;
 281                 offset = entry - bufnum * FAT12BUFSIZE;
 282                 break;
 283         default:
 284                 /* Unsupported FAT size */
 285                 return -1;
 286         }
 287
 288         /* Read a new block of FAT entries into the cache. */
 289         if (bufnum != mydata->fatbufnum) {
 290                 int getsize = FATBUFBLOCKS;
 291                 __u8 *bufptr = mydata->fatbuf;
 292                 __u32 fatlength = mydata->fatlength;
 293                 __u32 startblock = bufnum * FATBUFBLOCKS;
 294
 295                 /* Cap length if fatlength is not a multiple of FATBUFBLOCKS */
 296                 if (startblock + getsize > fatlength)
 297                         getsize = fatlength - startblock;
 298
 299                 if (flush_dirty_fat_buffer(mydata) < 0)
 300                         return -1;
 301
 302                 startblock += mydata->fat_sect;
 303
 304                 if (disk_read(startblock, getsize, bufptr) < 0) {
 305                         debug("Error reading FAT blocks\n");
 306                         return -1;
 307                 }
 308                 mydata->fatbufnum = bufnum;
 309         }
 310
 311         /* Mark as dirty */
 312         mydata->fat_dirty = 1;
 313
 314         /* Set the actual entry */
 315         switch (mydata->fatsize) {
 316         case 32:
 317                 ((__u32 *) mydata->fatbuf)[offset] = cpu_to_le32(entry_value);
 318                 break;
 319         case 16:
 320                 ((__u16 *) mydata->fatbuf)[offset] = cpu_to_le16(entry_value);
 321                 break;
 322         case 12:
 323                 off16 = (offset * 3) / 4;
 324
 325                 switch (offset & 0x3) {
 326                 case 0:
 327                         val1 = cpu_to_le16(entry_value) & 0xfff;
 328                         ((__u16 *)mydata->fatbuf)[off16] &= ~0xfff;
 329                         ((__u16 *)mydata->fatbuf)[off16] |= val1;
 330                         break;
 331                 case 1:
 332                         val1 = cpu_to_le16(entry_value) & 0xf;
 333                         val2 = (cpu_to_le16(entry_value) >> 4) & 0xff;
 334
 335                         ((__u16 *)mydata->fatbuf)[off16] &= ~0xf000;
 336                         ((__u16 *)mydata->fatbuf)[off16] |= (val1 << 12);
 337
 338                         ((__u16 *)mydata->fatbuf)[off16 + 1] &= ~0xff;
 339                         ((__u16 *)mydata->fatbuf)[off16 + 1] |= val2;
 340                         break;
 341                 case 2:
 342                         val1 = cpu_to_le16(entry_value) & 0xff;
 343                         val2 = (cpu_to_le16(entry_value) >> 8) & 0xf;
 344
 345                         ((__u16 *)mydata->fatbuf)[off16] &= ~0xff00;
 346                         ((__u16 *)mydata->fatbuf)[off16] |= (val1 << 8);
 347
 348                         ((__u16 *)mydata->fatbuf)[off16 + 1] &= ~0xf;
 349                         ((__u16 *)mydata->fatbuf)[off16 + 1] |= val2;
 350                         break;
 351                 case 3:
 352                         val1 = cpu_to_le16(entry_value) & 0xfff;
 353                         ((__u16 *)mydata->fatbuf)[off16] &= ~0xfff0;
 354                         ((__u16 *)mydata->fatbuf)[off16] |= (val1 << 4);
 355                         break;
 356                 default:
 357                         break;
 358                 }
 359
 360                 break;
 361         default:
 362                 return -1;
 363         }
 364
 365         return 0;
 366 }
 367
 368 /*
 369  * Determine the next free cluster after 'entry' in a FAT (12/16/32) table
 370  * and link it to 'entry'. EOC marker is not set on returned entry.
 371  */
 372 static __u32 determine_fatent(fsdata *mydata, __u32 entry)
 373 {
 374         __u32 next_fat, next_entry = entry + 1;
 375
 376         while (1) {
 377                 next_fat = get_fatent(mydata, next_entry);
 378                 if (next_fat == 0) {
 379                         /* found free entry, link to entry */
 380                         set_fatent_value(mydata, entry, next_entry);
 381                         break;
 382                 }
 383                 next_entry++;
 384         }
 385         debug("FAT%d: entry: %08x, entry_value: %04x\n",
 386                mydata->fatsize, entry, next_entry);
 387
 388         return next_entry;
 389 }
 390
 391 /**
 392  * set_sectors() - write data to sectors
 393  *
 394  * Write 'size' bytes from 'buffer' into the specified sector.
 395  *
 396  * @mydata:     data to be written
 397  * @startsect:  sector to be written to
 398  * @buffer:     data to be written
 399  * @size:       bytes to be written (but not more than the size of a cluster)
 400  * Return:      0 on success, -1 otherwise
 401  */
 402 static int
 403 set_sectors(fsdata *mydata, u32 startsect, u8 *buffer, u32 size)
 404 {
 405         u32 nsects = 0;
 406         int ret;
 407
 408         debug("startsect: %d\n", startsect);
 409
 410         if ((unsigned long)buffer & (ARCH_DMA_MINALIGN - 1)) {
 411                 ALLOC_CACHE_ALIGN_BUFFER(__u8, tmpbuf, mydata->sect_size);
 412
 413                 debug("FAT: Misaligned buffer address (%p)\n", buffer);
 414
 415                 while (size >= mydata->sect_size) {
 416                         memcpy(tmpbuf, buffer, mydata->sect_size);
 417                         ret = disk_write(startsect++, 1, tmpbuf);
 418                         if (ret != 1) {
 419                                 debug("Error writing data (got %d)\n", ret);
 420                                 return -1;
 421                         }
 422
 423                         buffer += mydata->sect_size;
 424                         size -= mydata->sect_size;
 425                 }
 426         } else if (size >= mydata->sect_size) {
 427                 nsects = size / mydata->sect_size;
 428                 ret = disk_write(startsect, nsects, buffer);
 429                 if (ret != nsects) {
 430                         debug("Error writing data (got %d)\n", ret);
 431                         return -1;
 432                 }
 433
 434                 startsect += nsects;
 435                 buffer += nsects * mydata->sect_size;
 436                 size -= nsects * mydata->sect_size;
 437         }
 438
 439         if (size) {
 440                 ALLOC_CACHE_ALIGN_BUFFER(__u8, tmpbuf, mydata->sect_size);
 441                 /* Do not leak content of stack */
 442                 memset(tmpbuf, 0, mydata->sect_size);
 443                 memcpy(tmpbuf, buffer, size);
 444                 ret = disk_write(startsect, 1, tmpbuf);
 445                 if (ret != 1) {
 446                         debug("Error writing data (got %d)\n", ret);
 447                         return -1;
 448                 }
 449         }
 450
 451         return 0;
 452 }
 453
 454 /**
 455  * set_cluster() - write data to cluster
 456  *
 457  * Write 'size' bytes from 'buffer' into the specified cluster.
 458  *
 459  * @mydata:     data to be written
 460  * @clustnum:   cluster to be written to
 461  * @buffer:     data to be written
 462  * @size:       bytes to be written (but not more than the size of a cluster)
 463  * Return:      0 on success, -1 otherwise
 464  */
 465 static int
 466 set_cluster(fsdata *mydata, u32 clustnum, u8 *buffer, u32 size)
 467 {
 468         return set_sectors(mydata, clust_to_sect(mydata, clustnum),
 469                            buffer, size);
 470 }
 471
 472 static int
 473 flush_dir(fat_itr *itr)
 474 {
 475         fsdata *mydata = itr->fsdata;
 476         u32 startsect, sect_offset, nsects;
 477
 478         if (!itr->is_root || mydata->fatsize == 32)
 479                 return set_cluster(mydata, itr->clust, itr->block,
 480                                    mydata->clust_size * mydata->sect_size);
 481
 482         sect_offset = itr->clust * mydata->clust_size;
 483         startsect = mydata->rootdir_sect + sect_offset;
 484         /* do not write past the end of rootdir */
 485         nsects = min_t(u32, mydata->clust_size,
 486                        mydata->rootdir_size - sect_offset);
 487
 488         return set_sectors(mydata, startsect, itr->block,
 489                            nsects * mydata->sect_size);
 490 }
 491
 492 static __u8 tmpbuf_cluster[MAX_CLUSTSIZE] __aligned(ARCH_DMA_MINALIGN);
 493
 494 /*
 495  * Read and modify data on existing and consecutive cluster blocks
 496  */
 497 static int
 498 get_set_cluster(fsdata *mydata, __u32 clustnum, loff_t pos, __u8 *buffer,
 499                 loff_t size, loff_t *gotsize)
 500 {
 501         unsigned int bytesperclust = mydata->clust_size * mydata->sect_size;
 502         __u32 startsect;
 503         loff_t wsize;
 504         int clustcount, i, ret;
 505
 506         *gotsize = 0;
 507         if (!size)
 508                 return 0;
 509
 510         assert(pos < bytesperclust);
 511         startsect = clust_to_sect(mydata, clustnum);
 512
 513         debug("clustnum: %d, startsect: %d, pos: %lld\n",
 514               clustnum, startsect, pos);
 515
 516         /* partial write at beginning */
 517         if (pos) {
 518                 wsize = min(bytesperclust - pos, size);
 519                 ret = disk_read(startsect, mydata->clust_size, tmpbuf_cluster);
 520                 if (ret != mydata->clust_size) {
 521                         debug("Error reading data (got %d)\n", ret);
 522                         return -1;
 523                 }
 524
 525                 memcpy(tmpbuf_cluster + pos, buffer, wsize);
 526                 ret = disk_write(startsect, mydata->clust_size, tmpbuf_cluster);
 527                 if (ret != mydata->clust_size) {
 528                         debug("Error writing data (got %d)\n", ret);
 529                         return -1;
 530                 }
 531
 532                 size -= wsize;
 533                 buffer += wsize;
 534                 *gotsize += wsize;
 535
 536                 startsect += mydata->clust_size;
 537
 538                 if (!size)
 539                         return 0;
 540         }
 541
 542         /* full-cluster write */
 543         if (size >= bytesperclust) {
 544                 clustcount = lldiv(size, bytesperclust);
 545
 546                 if (!((unsigned long)buffer & (ARCH_DMA_MINALIGN - 1))) {
 547                         wsize = clustcount * bytesperclust;
 548                         ret = disk_write(startsect,
 549                                          clustcount * mydata->clust_size,
 550                                          buffer);
 551                         if (ret != clustcount * mydata->clust_size) {
 552                                 debug("Error writing data (got %d)\n", ret);
 553                                 return -1;
 554                         }
 555
 556                         size -= wsize;
 557                         buffer += wsize;
 558                         *gotsize += wsize;
 559
 560                         startsect += clustcount * mydata->clust_size;
 561                 } else {
 562                         for (i = 0; i < clustcount; i++) {
 563                                 memcpy(tmpbuf_cluster, buffer, bytesperclust);
 564                                 ret = disk_write(startsect,
 565                                                  mydata->clust_size,
 566                                                  tmpbuf_cluster);
 567                                 if (ret != mydata->clust_size) {
 568                                         debug("Error writing data (got %d)\n",
 569                                               ret);
 570                                         return -1;
 571                                 }
 572
 573                                 size -= bytesperclust;
 574                                 buffer += bytesperclust;
 575                                 *gotsize += bytesperclust;
 576
 577                                 startsect += mydata->clust_size;
 578                         }
 579                 }
 580         }
 581
 582         /* partial write at end */
 583         if (size) {
 584                 wsize = size;
 585                 ret = disk_read(startsect, mydata->clust_size, tmpbuf_cluster);
 586                 if (ret != mydata->clust_size) {
 587                         debug("Error reading data (got %d)\n", ret);
 588                         return -1;
 589                 }
 590                 memcpy(tmpbuf_cluster, buffer, wsize);
 591                 ret = disk_write(startsect, mydata->clust_size, tmpbuf_cluster);
 592                 if (ret != mydata->clust_size) {
 593                         debug("Error writing data (got %d)\n", ret);
 594                         return -1;
 595                 }
 596
 597                 size -= wsize;
 598                 buffer += wsize;
 599                 *gotsize += wsize;
 600         }
 601
 602         assert(!size);
 603
 604         return 0;
 605 }
 606
 607 /*
 608  * Find the first empty cluster
 609  */
 610 static int find_empty_cluster(fsdata *mydata)
 611 {
 612         __u32 fat_val, entry = 3;
 613
 614         while (1) {
 615                 fat_val = get_fatent(mydata, entry);
 616                 if (fat_val == 0)
 617                         break;
 618                 entry++;
 619         }
 620
 621         return entry;
 622 }
 623
 624 /*
 625  * Allocate a cluster for additional directory entries
 626  */
 627 static int new_dir_table(fat_itr *itr)
 628 {
 629         fsdata *mydata = itr->fsdata;
 630         int dir_newclust = 0;
 631         unsigned int bytesperclust = mydata->clust_size * mydata->sect_size;
 632
 633         dir_newclust = find_empty_cluster(mydata);
 634         set_fatent_value(mydata, itr->clust, dir_newclust);
 635         if (mydata->fatsize == 32)
 636                 set_fatent_value(mydata, dir_newclust, 0xffffff8);
 637         else if (mydata->fatsize == 16)
 638                 set_fatent_value(mydata, dir_newclust, 0xfff8);
 639         else if (mydata->fatsize == 12)
 640                 set_fatent_value(mydata, dir_newclust, 0xff8);
 641
 642         itr->clust = dir_newclust;
 643         itr->next_clust = dir_newclust;
 644
 645         if (flush_dirty_fat_buffer(mydata) < 0)
 646                 return -1;
 647
 648         memset(itr->block, 0x00, bytesperclust);
 649
 650         itr->dent = (dir_entry *)itr->block;
 651         itr->last_cluster = 1;
 652         itr->remaining = bytesperclust / sizeof(dir_entry) - 1;
 653
 654         return 0;
 655 }
 656
 657 /*
 658  * Set empty cluster from 'entry' to the end of a file
 659  */
 660 static int clear_fatent(fsdata *mydata, __u32 entry)
 661 {
 662         __u32 fat_val;
 663
 664         while (!CHECK_CLUST(entry, mydata->fatsize)) {
 665                 fat_val = get_fatent(mydata, entry);
 666                 if (fat_val != 0)
 667                         set_fatent_value(mydata, entry, 0);
 668                 else
 669                         break;
 670
 671                 entry = fat_val;
 672         }
 673
 674         /* Flush fat buffer */
 675         if (flush_dirty_fat_buffer(mydata) < 0)
 676                 return -1;
 677
 678         return 0;
 679 }
 680
 681 /*
 682  * Set start cluster in directory entry
 683  */
 684 static void set_start_cluster(const fsdata *mydata, dir_entry *dentptr,
 685                               __u32 start_cluster)
 686 {
 687         if (mydata->fatsize == 32)
 688                 dentptr->starthi =
 689                         cpu_to_le16((start_cluster & 0xffff0000) >> 16);
 690         dentptr->start = cpu_to_le16(start_cluster & 0xffff);
 691 }
 692
 693 /*
 694  * Check whether adding a file makes the file system to
 695  * exceed the size of the block device
 696  * Return -1 when overflow occurs, otherwise return 0
 697  */
 698 static int check_overflow(fsdata *mydata, __u32 clustnum, loff_t size)
 699 {
 700         __u32 startsect, sect_num, offset;
 701
 702         if (clustnum > 0)
 703                 startsect = clust_to_sect(mydata, clustnum);
 704         else
 705                 startsect = mydata->rootdir_sect;
 706
 707         sect_num = div_u64_rem(size, mydata->sect_size, &offset);
 708
 709         if (offset != 0)
 710                 sect_num++;
 711
 712         if (startsect + sect_num > total_sector)
 713                 return -1;
 714         return 0;
 715 }
 716
 717 /*
 718  * Write at most 'maxsize' bytes from 'buffer' into
 719  * the file associated with 'dentptr'
 720  * Update the number of bytes written in *gotsize and return 0
 721  * or return -1 on fatal errors.
 722  */
 723 static int
 724 set_contents(fsdata *mydata, dir_entry *dentptr, loff_t pos, __u8 *buffer,
 725              loff_t maxsize, loff_t *gotsize)
 726 {
 727         unsigned int bytesperclust = mydata->clust_size * mydata->sect_size;
 728         __u32 curclust = START(dentptr);
 729         __u32 endclust = 0, newclust = 0;
 730         u64 cur_pos, filesize;
 731         loff_t offset, actsize, wsize;
 732
 733         *gotsize = 0;
 734         filesize = pos + maxsize;
 735
 736         debug("%llu bytes\n", filesize);
 737
 738         if (!filesize) {
 739                 if (!curclust)
 740                         return 0;
 741                 if (!CHECK_CLUST(curclust, mydata->fatsize) ||
 742                     IS_LAST_CLUST(curclust, mydata->fatsize)) {
 743                         clear_fatent(mydata, curclust);
 744                         set_start_cluster(mydata, dentptr, 0);
 745                         return 0;
 746                 }
 747                 debug("curclust: 0x%x\n", curclust);
 748                 debug("Invalid FAT entry\n");
 749                 return -1;
 750         }
 751
 752         if (!curclust) {
 753                 assert(pos == 0);
 754                 goto set_clusters;
 755         }
 756
 757         /* go to cluster at pos */
 758         cur_pos = bytesperclust;
 759         while (1) {
 760                 if (pos <= cur_pos)
 761                         break;
 762                 if (IS_LAST_CLUST(curclust, mydata->fatsize))
 763                         break;
 764
 765                 newclust = get_fatent(mydata, curclust);
 766                 if (!IS_LAST_CLUST(newclust, mydata->fatsize) &&
 767                     CHECK_CLUST(newclust, mydata->fatsize)) {
 768                         debug("curclust: 0x%x\n", curclust);
 769                         debug("Invalid FAT entry\n");
 770                         return -1;
 771                 }
 772
 773                 cur_pos += bytesperclust;
 774                 curclust = newclust;
 775         }
 776         if (IS_LAST_CLUST(curclust, mydata->fatsize)) {
 777                 assert(pos == cur_pos);
 778                 goto set_clusters;
 779         }
 780
 781         assert(pos < cur_pos);
 782         cur_pos -= bytesperclust;
 783
 784         /* overwrite */
 785         assert(IS_LAST_CLUST(curclust, mydata->fatsize) ||
 786                !CHECK_CLUST(curclust, mydata->fatsize));
 787
 788         while (1) {
 789                 /* search for allocated consecutive clusters */
 790                 actsize = bytesperclust;
 791                 endclust = curclust;
 792                 while (1) {
 793                         if (filesize <= (cur_pos + actsize))
 794                                 break;
 795
 796                         newclust = get_fatent(mydata, endclust);
 797
 798                         if (newclust != endclust + 1)
 799                                 break;
 800                         if (IS_LAST_CLUST(newclust, mydata->fatsize))
 801                                 break;
 802                         if (CHECK_CLUST(newclust, mydata->fatsize)) {
 803                                 debug("curclust: 0x%x\n", curclust);
 804                                 debug("Invalid FAT entry\n");
 805                                 return -1;
 806                         }
 807
 808                         actsize += bytesperclust;
 809                         endclust = newclust;
 810                 }
 811
 812                 /* overwrite to <curclust..endclust> */
 813                 if (pos < cur_pos)
 814                         offset = 0;
 815                 else
 816                         offset = pos - cur_pos;
 817                 wsize = min_t(unsigned long long, actsize, filesize - cur_pos);
 818                 wsize -= offset;
 819
 820                 if (get_set_cluster(mydata, curclust, offset,
 821                                     buffer, wsize, &actsize)) {
 822                         printf("Error get-and-setting cluster\n");
 823                         return -1;
 824                 }
 825                 buffer += wsize;
 826                 *gotsize += wsize;
 827                 cur_pos += offset + wsize;
 828
 829                 if (filesize <= cur_pos)
 830                         break;
 831
 832                 if (IS_LAST_CLUST(newclust, mydata->fatsize))
 833                         /* no more clusters */
 834                         break;
 835
 836                 curclust = newclust;
 837         }
 838
 839         if (filesize <= cur_pos) {
 840                 /* no more write */
 841                 newclust = get_fatent(mydata, endclust);
 842                 if (!IS_LAST_CLUST(newclust, mydata->fatsize)) {
 843                         /* truncate the rest */
 844                         clear_fatent(mydata, newclust);
 845
 846                         /* Mark end of file in FAT */
 847                         if (mydata->fatsize == 12)
 848                                 newclust = 0xfff;
 849                         else if (mydata->fatsize == 16)
 850                                 newclust = 0xffff;
 851                         else if (mydata->fatsize == 32)
 852                                 newclust = 0xfffffff;
 853                         set_fatent_value(mydata, endclust, newclust);
 854                 }
 855
 856                 return 0;
 857         }
 858
 859         curclust = endclust;
 860         filesize -= cur_pos;
 861         assert(!do_div(cur_pos, bytesperclust));
 862
 863 set_clusters:
 864         /* allocate and write */
 865         assert(!pos);
 866
 867         /* Assure that curclust is valid */
 868         if (!curclust) {
 869                 curclust = find_empty_cluster(mydata);
 870                 set_start_cluster(mydata, dentptr, curclust);
 871         } else {
 872                 newclust = get_fatent(mydata, curclust);
 873
 874                 if (IS_LAST_CLUST(newclust, mydata->fatsize)) {
 875                         newclust = determine_fatent(mydata, curclust);
 876                         set_fatent_value(mydata, curclust, newclust);
 877                         curclust = newclust;
 878                 } else {
 879                         debug("error: something wrong\n");
 880                         return -1;
 881                 }
 882         }
 883
 884         /* TODO: already partially written */
 885         if (check_overflow(mydata, curclust, filesize)) {
 886                 printf("Error: no space left: %llu\n", filesize);
 887                 return -1;
 888         }
 889
 890         actsize = bytesperclust;
 891         endclust = curclust;
 892         do {
 893                 /* search for consecutive clusters */
 894                 while (actsize < filesize) {
 895                         newclust = determine_fatent(mydata, endclust);
 896
 897                         if ((newclust - 1) != endclust)
 898                                 /* write to <curclust..endclust> */
 899                                 goto getit;
 900
 901                         if (CHECK_CLUST(newclust, mydata->fatsize)) {
 902                                 debug("newclust: 0x%x\n", newclust);
 903                                 debug("Invalid FAT entry\n");
 904                                 return 0;
 905                         }
 906                         endclust = newclust;
 907                         actsize += bytesperclust;
 908                 }
 909
 910                 /* set remaining bytes */
 911                 actsize = filesize;
 912                 if (set_cluster(mydata, curclust, buffer, (u32)actsize) != 0) {
 913                         debug("error: writing cluster\n");
 914                         return -1;
 915                 }
 916                 *gotsize += actsize;
 917
 918                 /* Mark end of file in FAT */
 919                 if (mydata->fatsize == 12)
 920                         newclust = 0xfff;
 921                 else if (mydata->fatsize == 16)
 922                         newclust = 0xffff;
 923                 else if (mydata->fatsize == 32)
 924                         newclust = 0xfffffff;
 925                 set_fatent_value(mydata, endclust, newclust);
 926
 927                 return 0;
 928 getit:
 929                 if (set_cluster(mydata, curclust, buffer, (u32)actsize) != 0) {
 930                         debug("error: writing cluster\n");
 931                         return -1;
 932                 }
 933                 *gotsize += actsize;
 934                 filesize -= actsize;
 935                 buffer += actsize;
 936
 937                 if (CHECK_CLUST(newclust, mydata->fatsize)) {
 938                         debug("newclust: 0x%x\n", newclust);
 939                         debug("Invalid FAT entry\n");
 940                         return 0;
 941                 }
 942                 actsize = bytesperclust;
 943                 curclust = endclust = newclust;
 944         } while (1);
 945
 946         return 0;
 947 }
 948
 949 /*
 950  * Fill dir_entry
 951  */
 952 static void fill_dentry(fsdata *mydata, dir_entry *dentptr,
 953         const char *filename, __u32 start_cluster, __u32 size, __u8 attr)
 954 {
 955         set_start_cluster(mydata, dentptr, start_cluster);
 956         dentptr->size = cpu_to_le32(size);
 957
 958         dentptr->attr = attr;
 959
 960         set_name(dentptr, filename);
 961 }
 962
 963 /*
 964  * Find a directory entry based on filename or start cluster number
 965  * If the directory entry is not found,
 966  * the new position for writing a directory entry will be returned
 967  */
 968 static dir_entry *find_directory_entry(fat_itr *itr, char *filename)
 969 {
 970         int match = 0;
 971
 972         while (fat_itr_next(itr)) {
 973                 /* check both long and short name: */
 974                 if (!strcasecmp(filename, itr->name))
 975                         match = 1;
 976                 else if (itr->name != itr->s_name &&
 977                          !strcasecmp(filename, itr->s_name))
 978                         match = 1;
 979
 980                 if (!match)
 981                         continue;
 982
 983                 if (itr->dent->name[0] == '\0')
 984                         return NULL;
 985                 else
 986                         return itr->dent;
 987         }
 988
 989         /* allocate a cluster for more entries */
 990         if (!itr->dent &&
 991             (!itr->is_root || itr->fsdata->fatsize == 32) &&
 992             new_dir_table(itr))
 993                 /* indicate that allocating dent failed */
 994                 itr->dent = NULL;
 995
 996         return NULL;
 997 }
 998
 999 static int split_filename(char *filename, char **dirname, char **basename)
1000 {
1001         char *p, *last_slash, *last_slash_cont;
1002
1003 again:
1004         p = filename;
1005         last_slash = NULL;
1006         last_slash_cont = NULL;
1007         while (*p) {
1008                 if (ISDIRDELIM(*p)) {
1009                         last_slash = p;
1010                         last_slash_cont = p;
1011                         /* continuous slashes */
1012                         while (ISDIRDELIM(*p))
1013                                 last_slash_cont = p++;
1014                         if (!*p)
1015                                 break;
1016                 }
1017                 p++;
1018         }
1019
1020         if (last_slash) {
1021                 if (last_slash_cont == (filename + strlen(filename) - 1)) {
1022                         /* remove trailing slashes */
1023                         *last_slash = '\0';
1024                         goto again;
1025                 }
1026
1027                 if (last_slash == filename) {
1028                         /* avoid ""(null) directory */
1029                         *dirname = "/";
1030                 } else {
1031                         *last_slash = '\0';
1032                         *dirname = filename;
1033                 }
1034
1035                 *last_slash_cont = '\0';
1036                 *basename = last_slash_cont + 1;
1037         } else {
1038                 *dirname = "/"; /* root by default */
1039                 *basename = filename;
1040         }
1041
1042         return 0;
1043 }
1044
1045 /**
1046  * normalize_longname() - check long file name and convert to lower case
1047  *
1048  * We assume here that the FAT file system is using an 8bit code page.
1049  * Linux typically uses CP437, EDK2 assumes CP1250.
1050  *
1051  * @l_filename: preallocated buffer receiving the normalized name
1052  * @filename:   filename to normalize
1053  * Return:      0 on success, -1 on failure
1054  */
1055 static int normalize_longname(char *l_filename, const char *filename)
1056 {
1057         const char *p, illegal[] = "<>:\"/\\|?*";
1058
1059         if (strlen(filename) >= VFAT_MAXLEN_BYTES)
1060                 return -1;
1061
1062         for (p = filename; *p; ++p) {
1063                 if ((unsigned char)*p < 0x20)
1064                         return -1;
1065                 if (strchr(illegal, *p))
1066                         return -1;
1067         }
1068
1069         strcpy(l_filename, filename);
1070         downcase(l_filename, VFAT_MAXLEN_BYTES);
1071
1072         return 0;
1073 }
1074
1075 int file_fat_write_at(const char *filename, loff_t pos, void *buffer,
1076                       loff_t size, loff_t *actwrite)
1077 {
1078         dir_entry *retdent;
1079         fsdata datablock = { .fatbuf = NULL, };
1080         fsdata *mydata = &datablock;
1081         fat_itr *itr = NULL;
1082         int ret = -1;
1083         char *filename_copy, *parent, *basename;
1084         char l_filename[VFAT_MAXLEN_BYTES];
1085
1086         debug("writing %s\n", filename);
1087
1088         filename_copy = strdup(filename);
1089         if (!filename_copy)
1090                 return -ENOMEM;
1091
1092         split_filename(filename_copy, &parent, &basename);
1093         if (!strlen(basename)) {
1094                 ret = -EINVAL;
1095                 goto exit;
1096         }
1097
1098         filename = basename;
1099         if (normalize_longname(l_filename, filename)) {
1100                 printf("FAT: illegal filename (%s)\n", filename);
1101                 ret = -EINVAL;
1102                 goto exit;
1103         }
1104
1105         itr = malloc_cache_aligned(sizeof(fat_itr));
1106         if (!itr) {
1107                 ret = -ENOMEM;
1108                 goto exit;
1109         }
1110
1111         ret = fat_itr_root(itr, &datablock);
1112         if (ret)
1113                 goto exit;
1114
1115         total_sector = datablock.total_sect;
1116
1117         ret = fat_itr_resolve(itr, parent, TYPE_DIR);
1118         if (ret) {
1119                 printf("%s: doesn't exist (%d)\n", parent, ret);
1120                 goto exit;
1121         }
1122
1123         retdent = find_directory_entry(itr, l_filename);
1124
1125         if (retdent) {
1126                 if (fat_itr_isdir(itr)) {
1127                         ret = -EISDIR;
1128                         goto exit;
1129                 }
1130
1131                 /* A file exists */
1132                 if (pos == -1)
1133                         /* Append to the end */
1134                         pos = FAT2CPU32(retdent->size);
1135                 if (pos > retdent->size) {
1136                         /* No hole allowed */
1137                         ret = -EINVAL;
1138                         goto exit;
1139                 }
1140
1141                 /* Update file size in a directory entry */
1142                 retdent->size = cpu_to_le32(pos + size);
1143         } else {
1144                 /* Create a new file */
1145
1146                 if (itr->is_root) {
1147                         /* root dir cannot have "." or ".." */
1148                         if (!strcmp(l_filename, ".") ||
1149                             !strcmp(l_filename, "..")) {
1150                                 ret = -EINVAL;
1151                                 goto exit;
1152                         }
1153                 }
1154
1155                 if (!itr->dent) {
1156                         printf("Error: allocating new dir entry\n");
1157                         ret = -EIO;
1158                         goto exit;
1159                 }
1160
1161                 if (pos) {
1162                         /* No hole allowed */
1163                         ret = -EINVAL;
1164                         goto exit;
1165                 }
1166
1167                 memset(itr->dent, 0, sizeof(*itr->dent));
1168
1169                 /* Calculate checksum for short name */
1170                 set_name(itr->dent, filename);
1171
1172                 /* Set long name entries */
1173                 if (fill_dir_slot(itr, filename)) {
1174                         ret = -EIO;
1175                         goto exit;
1176                 }
1177
1178                 /* Set short name entry */
1179                 fill_dentry(itr->fsdata, itr->dent, filename, 0, size, 0x20);
1180
1181                 retdent = itr->dent;
1182         }
1183
1184         ret = set_contents(mydata, retdent, pos, buffer, size, actwrite);
1185         if (ret < 0) {
1186                 printf("Error: writing contents\n");
1187                 ret = -EIO;
1188                 goto exit;
1189         }
1190         debug("attempt to write 0x%llx bytes\n", *actwrite);
1191
1192         /* Flush fat buffer */
1193         ret = flush_dirty_fat_buffer(mydata);
1194         if (ret) {
1195                 printf("Error: flush fat buffer\n");
1196                 ret = -EIO;
1197                 goto exit;
1198         }
1199
1200         /* Write directory table to device */
1201         ret = flush_dir(itr);
1202         if (ret) {
1203                 printf("Error: writing directory entry\n");
1204                 ret = -EIO;
1205         }
1206
1207 exit:
1208         free(filename_copy);
1209         free(mydata->fatbuf);
1210         free(itr);
1211         return ret;
1212 }
1213
1214 int file_fat_write(const char *filename, void *buffer, loff_t offset,
1215                    loff_t maxsize, loff_t *actwrite)
1216 {
1217         return file_fat_write_at(filename, offset, buffer, maxsize, actwrite);
1218 }
1219
1220 static int fat_dir_entries(fat_itr *itr)
1221 {
1222         fat_itr *dirs;
1223         fsdata fsdata = { .fatbuf = NULL, }, *mydata = &fsdata;
1224                                                 /* for FATBUFSIZE */
1225         int count;
1226
1227         dirs = malloc_cache_aligned(sizeof(fat_itr));
1228         if (!dirs) {
1229                 debug("Error: allocating memory\n");
1230                 count = -ENOMEM;
1231                 goto exit;
1232         }
1233
1234         /* duplicate fsdata */
1235         fat_itr_child(dirs, itr);
1236         fsdata = *dirs->fsdata;
1237
1238         /* allocate local fat buffer */
1239         fsdata.fatbuf = malloc_cache_aligned(FATBUFSIZE);
1240         if (!fsdata.fatbuf) {
1241                 debug("Error: allocating memory\n");
1242                 count = -ENOMEM;
1243                 goto exit;
1244         }
1245         fsdata.fatbufnum = -1;
1246         dirs->fsdata = &fsdata;
1247
1248         for (count = 0; fat_itr_next(dirs); count++)
1249                 ;
1250
1251 exit:
1252         free(fsdata.fatbuf);
1253         free(dirs);
1254         return count;
1255 }
1256
1257 static int delete_dentry(fat_itr *itr)
1258 {
1259         fsdata *mydata = itr->fsdata;
1260         dir_entry *dentptr = itr->dent;
1261
1262         /* free cluster blocks */
1263         clear_fatent(mydata, START(dentptr));
1264         if (flush_dirty_fat_buffer(mydata) < 0) {
1265                 printf("Error: flush fat buffer\n");
1266                 return -EIO;
1267         }
1268
1269         /*
1270          * update a directory entry
1271          * TODO:
1272          *  - long file name support
1273          *  - find and mark the "new" first invalid entry as name[0]=0x00
1274          */
1275         memset(dentptr, 0, sizeof(*dentptr));
1276         dentptr->name[0] = 0xe5;
1277
1278         if (flush_dir(itr)) {
1279                 printf("error: writing directory entry\n");
1280                 return -EIO;
1281         }
1282
1283         return 0;
1284 }
1285
1286 int fat_unlink(const char *filename)
1287 {
1288         fsdata fsdata = { .fatbuf = NULL, };
1289         fat_itr *itr = NULL;
1290         int n_entries, ret;
1291         char *filename_copy, *dirname, *basename;
1292
1293         filename_copy = strdup(filename);
1294         if (!filename_copy) {
1295                 printf("Error: allocating memory\n");
1296                 ret = -ENOMEM;
1297                 goto exit;
1298         }
1299         split_filename(filename_copy, &dirname, &basename);
1300
1301         if (!strcmp(dirname, "/") && !strcmp(basename, "")) {
1302                 printf("Error: cannot remove root\n");
1303                 ret = -EINVAL;
1304                 goto exit;
1305         }
1306
1307         itr = malloc_cache_aligned(sizeof(fat_itr));
1308         if (!itr) {
1309                 printf("Error: allocating memory\n");
1310                 ret = -ENOMEM;
1311                 goto exit;
1312         }
1313
1314         ret = fat_itr_root(itr, &fsdata);
1315         if (ret)
1316                 goto exit;
1317
1318         total_sector = fsdata.total_sect;
1319
1320         ret = fat_itr_resolve(itr, dirname, TYPE_DIR);
1321         if (ret) {
1322                 printf("%s: doesn't exist (%d)\n", dirname, ret);
1323                 ret = -ENOENT;
1324                 goto exit;
1325         }
1326
1327         if (!find_directory_entry(itr, basename)) {
1328                 printf("%s: doesn't exist\n", basename);
1329                 ret = -ENOENT;
1330                 goto exit;
1331         }
1332
1333         if (fat_itr_isdir(itr)) {
1334                 n_entries = fat_dir_entries(itr);
1335                 if (n_entries < 0) {
1336                         ret = n_entries;
1337                         goto exit;
1338                 }
1339                 if (n_entries > 2) {
1340                         printf("Error: directory is not empty: %d\n",
1341                                n_entries);
1342                         ret = -EINVAL;
1343                         goto exit;
1344                 }
1345         }
1346
1347         ret = delete_dentry(itr);
1348
1349 exit:
1350         free(fsdata.fatbuf);
1351         free(itr);
1352         free(filename_copy);
1353
1354         return ret;
1355 }
1356
1357 int fat_mkdir(const char *new_dirname)
1358 {
1359         dir_entry *retdent;
1360         fsdata datablock = { .fatbuf = NULL, };
1361         fsdata *mydata = &datablock;
1362         fat_itr *itr = NULL;
1363         char *dirname_copy, *parent, *dirname;
1364         char l_dirname[VFAT_MAXLEN_BYTES];
1365         int ret = -1;
1366         loff_t actwrite;
1367         unsigned int bytesperclust;
1368         dir_entry *dotdent = NULL;
1369
1370         dirname_copy = strdup(new_dirname);
1371         if (!dirname_copy)
1372                 goto exit;
1373
1374         split_filename(dirname_copy, &parent, &dirname);
1375         if (!strlen(dirname)) {
1376                 ret = -EINVAL;
1377                 goto exit;
1378         }
1379
1380         if (normalize_longname(l_dirname, dirname)) {
1381                 printf("FAT: illegal filename (%s)\n", dirname);
1382                 ret = -EINVAL;
1383                 goto exit;
1384         }
1385
1386         itr = malloc_cache_aligned(sizeof(fat_itr));
1387         if (!itr) {
1388                 ret = -ENOMEM;
1389                 goto exit;
1390         }
1391
1392         ret = fat_itr_root(itr, &datablock);
1393         if (ret)
1394                 goto exit;
1395
1396         total_sector = datablock.total_sect;
1397
1398         ret = fat_itr_resolve(itr, parent, TYPE_DIR);
1399         if (ret) {
1400                 printf("%s: doesn't exist (%d)\n", parent, ret);
1401                 goto exit;
1402         }
1403
1404         retdent = find_directory_entry(itr, l_dirname);
1405
1406         if (retdent) {
1407                 printf("%s: already exists\n", l_dirname);
1408                 ret = -EEXIST;
1409                 goto exit;
1410         } else {
1411                 if (itr->is_root) {
1412                         /* root dir cannot have "." or ".." */
1413                         if (!strcmp(l_dirname, ".") ||
1414                             !strcmp(l_dirname, "..")) {
1415                                 ret = -EINVAL;
1416                                 goto exit;
1417                         }
1418                 }
1419
1420                 if (!itr->dent) {
1421                         printf("Error: allocating new dir entry\n");
1422                         ret = -EIO;
1423                         goto exit;
1424                 }
1425
1426                 memset(itr->dent, 0, sizeof(*itr->dent));
1427
1428                 /* Set short name to set alias checksum field in dir_slot */
1429                 set_name(itr->dent, dirname);
1430                 fill_dir_slot(itr, dirname);
1431
1432                 /* Set attribute as archive for regular file */
1433                 fill_dentry(itr->fsdata, itr->dent, dirname, 0, 0,
1434                             ATTR_DIR | ATTR_ARCH);
1435
1436                 retdent = itr->dent;
1437         }
1438
1439         /* Default entries */
1440         bytesperclust = mydata->clust_size * mydata->sect_size;
1441         dotdent = malloc_cache_aligned(bytesperclust);
1442         if (!dotdent) {
1443                 ret = -ENOMEM;
1444                 goto exit;
1445         }
1446         memset(dotdent, 0, bytesperclust);
1447
1448         memcpy(dotdent[0].name, ".       ", 8);
1449         memcpy(dotdent[0].ext, "   ", 3);
1450         dotdent[0].attr = ATTR_DIR | ATTR_ARCH;
1451
1452         memcpy(dotdent[1].name, "..      ", 8);
1453         memcpy(dotdent[1].ext, "   ", 3);
1454         dotdent[1].attr = ATTR_DIR | ATTR_ARCH;
1455         set_start_cluster(mydata, &dotdent[1], itr->start_clust);
1456
1457         ret = set_contents(mydata, retdent, 0, (__u8 *)dotdent,
1458                            bytesperclust, &actwrite);
1459         if (ret < 0) {
1460                 printf("Error: writing contents\n");
1461                 goto exit;
1462         }
1463         /* Write twice for "." */
1464         set_start_cluster(mydata, &dotdent[0], START(retdent));
1465         ret = set_contents(mydata, retdent, 0, (__u8 *)dotdent,
1466                            bytesperclust, &actwrite);
1467         if (ret < 0) {
1468                 printf("Error: writing contents\n");
1469                 goto exit;
1470         }
1471
1472         /* Flush fat buffer */
1473         ret = flush_dirty_fat_buffer(mydata);
1474         if (ret) {
1475                 printf("Error: flush fat buffer\n");
1476                 goto exit;
1477         }
1478
1479         /* Write directory table to device */
1480         ret = flush_dir(itr);
1481         if (ret)
1482                 printf("Error: writing directory entry\n");
1483
1484 exit:
1485         free(dirname_copy);
1486         free(mydata->fatbuf);
1487         free(itr);
1488         free(dotdent);
1489         return ret;
1490 }