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