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_cluster() - write data to cluster
 392  *
 393  * Write 'size' bytes from 'buffer' into the specified cluster.
 394  *
 395  * @mydata:     data to be written
 396  * @clustnum:   cluster 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_cluster(fsdata *mydata, u32 clustnum, u8 *buffer, u32 size)
 403 {
 404         u32 idx = 0;
 405         u32 startsect;
 406         int ret;
 407
 408         if (clustnum > 0)
 409                 startsect = clust_to_sect(mydata, clustnum);
 410         else
 411                 startsect = mydata->rootdir_sect;
 412
 413         debug("clustnum: %d, startsect: %d\n", clustnum, startsect);
 414
 415         if ((unsigned long)buffer & (ARCH_DMA_MINALIGN - 1)) {
 416                 ALLOC_CACHE_ALIGN_BUFFER(__u8, tmpbuf, mydata->sect_size);
 417
 418                 debug("FAT: Misaligned buffer address (%p)\n", buffer);
 419
 420                 while (size >= mydata->sect_size) {
 421                         memcpy(tmpbuf, buffer, mydata->sect_size);
 422                         ret = disk_write(startsect++, 1, tmpbuf);
 423                         if (ret != 1) {
 424                                 debug("Error writing data (got %d)\n", ret);
 425                                 return -1;
 426                         }
 427
 428                         buffer += mydata->sect_size;
 429                         size -= mydata->sect_size;
 430                 }
 431         } else if (size >= mydata->sect_size) {
 432                 idx = size / mydata->sect_size;
 433                 ret = disk_write(startsect, idx, buffer);
 434                 if (ret != idx) {
 435                         debug("Error writing data (got %d)\n", ret);
 436                         return -1;
 437                 }
 438
 439                 startsect += idx;
 440                 idx *= mydata->sect_size;
 441                 buffer += idx;
 442                 size -= idx;
 443         }
 444
 445         if (size) {
 446                 ALLOC_CACHE_ALIGN_BUFFER(__u8, tmpbuf, mydata->sect_size);
 447                 /* Do not leak content of stack */
 448                 memset(tmpbuf, 0, mydata->sect_size);
 449                 memcpy(tmpbuf, buffer, size);
 450                 ret = disk_write(startsect, 1, tmpbuf);
 451                 if (ret != 1) {
 452                         debug("Error writing data (got %d)\n", ret);
 453                         return -1;
 454                 }
 455         }
 456
 457         return 0;
 458 }
 459
 460 static __u8 tmpbuf_cluster[MAX_CLUSTSIZE] __aligned(ARCH_DMA_MINALIGN);
 461
 462 /*
 463  * Read and modify data on existing and consecutive cluster blocks
 464  */
 465 static int
 466 get_set_cluster(fsdata *mydata, __u32 clustnum, loff_t pos, __u8 *buffer,
 467                 loff_t size, loff_t *gotsize)
 468 {
 469         unsigned int bytesperclust = mydata->clust_size * mydata->sect_size;
 470         __u32 startsect;
 471         loff_t wsize;
 472         int clustcount, i, ret;
 473
 474         *gotsize = 0;
 475         if (!size)
 476                 return 0;
 477
 478         assert(pos < bytesperclust);
 479         startsect = clust_to_sect(mydata, clustnum);
 480
 481         debug("clustnum: %d, startsect: %d, pos: %lld\n",
 482               clustnum, startsect, pos);
 483
 484         /* partial write at beginning */
 485         if (pos) {
 486                 wsize = min(bytesperclust - pos, size);
 487                 ret = disk_read(startsect, mydata->clust_size, tmpbuf_cluster);
 488                 if (ret != mydata->clust_size) {
 489                         debug("Error reading data (got %d)\n", ret);
 490                         return -1;
 491                 }
 492
 493                 memcpy(tmpbuf_cluster + pos, buffer, wsize);
 494                 ret = disk_write(startsect, mydata->clust_size, tmpbuf_cluster);
 495                 if (ret != mydata->clust_size) {
 496                         debug("Error writing data (got %d)\n", ret);
 497                         return -1;
 498                 }
 499
 500                 size -= wsize;
 501                 buffer += wsize;
 502                 *gotsize += wsize;
 503
 504                 startsect += mydata->clust_size;
 505
 506                 if (!size)
 507                         return 0;
 508         }
 509
 510         /* full-cluster write */
 511         if (size >= bytesperclust) {
 512                 clustcount = lldiv(size, bytesperclust);
 513
 514                 if (!((unsigned long)buffer & (ARCH_DMA_MINALIGN - 1))) {
 515                         wsize = clustcount * bytesperclust;
 516                         ret = disk_write(startsect,
 517                                          clustcount * mydata->clust_size,
 518                                          buffer);
 519                         if (ret != clustcount * mydata->clust_size) {
 520                                 debug("Error writing data (got %d)\n", ret);
 521                                 return -1;
 522                         }
 523
 524                         size -= wsize;
 525                         buffer += wsize;
 526                         *gotsize += wsize;
 527
 528                         startsect += clustcount * mydata->clust_size;
 529                 } else {
 530                         for (i = 0; i < clustcount; i++) {
 531                                 memcpy(tmpbuf_cluster, buffer, bytesperclust);
 532                                 ret = disk_write(startsect,
 533                                                  mydata->clust_size,
 534                                                  tmpbuf_cluster);
 535                                 if (ret != mydata->clust_size) {
 536                                         debug("Error writing data (got %d)\n",
 537                                               ret);
 538                                         return -1;
 539                                 }
 540
 541                                 size -= bytesperclust;
 542                                 buffer += bytesperclust;
 543                                 *gotsize += bytesperclust;
 544
 545                                 startsect += mydata->clust_size;
 546                         }
 547                 }
 548         }
 549
 550         /* partial write at end */
 551         if (size) {
 552                 wsize = size;
 553                 ret = disk_read(startsect, mydata->clust_size, tmpbuf_cluster);
 554                 if (ret != mydata->clust_size) {
 555                         debug("Error reading data (got %d)\n", ret);
 556                         return -1;
 557                 }
 558                 memcpy(tmpbuf_cluster, buffer, wsize);
 559                 ret = disk_write(startsect, mydata->clust_size, tmpbuf_cluster);
 560                 if (ret != mydata->clust_size) {
 561                         debug("Error writing data (got %d)\n", ret);
 562                         return -1;
 563                 }
 564
 565                 size -= wsize;
 566                 buffer += wsize;
 567                 *gotsize += wsize;
 568         }
 569
 570         assert(!size);
 571
 572         return 0;
 573 }
 574
 575 /*
 576  * Find the first empty cluster
 577  */
 578 static int find_empty_cluster(fsdata *mydata)
 579 {
 580         __u32 fat_val, entry = 3;
 581
 582         while (1) {
 583                 fat_val = get_fatent(mydata, entry);
 584                 if (fat_val == 0)
 585                         break;
 586                 entry++;
 587         }
 588
 589         return entry;
 590 }
 591
 592 /*
 593  * Write directory entries in itr's buffer to block device
 594  */
 595 static int flush_dir_table(fat_itr *itr)
 596 {
 597         fsdata *mydata = itr->fsdata;
 598         int dir_newclust = 0;
 599         unsigned int bytesperclust = mydata->clust_size * mydata->sect_size;
 600
 601         if (set_cluster(mydata, itr->clust, itr->block, bytesperclust) != 0) {
 602                 printf("error: writing directory entry\n");
 603                 return -1;
 604         }
 605         dir_newclust = find_empty_cluster(mydata);
 606         set_fatent_value(mydata, itr->clust, dir_newclust);
 607         if (mydata->fatsize == 32)
 608                 set_fatent_value(mydata, dir_newclust, 0xffffff8);
 609         else if (mydata->fatsize == 16)
 610                 set_fatent_value(mydata, dir_newclust, 0xfff8);
 611         else if (mydata->fatsize == 12)
 612                 set_fatent_value(mydata, dir_newclust, 0xff8);
 613
 614         itr->clust = dir_newclust;
 615         itr->next_clust = dir_newclust;
 616
 617         if (flush_dirty_fat_buffer(mydata) < 0)
 618                 return -1;
 619
 620         memset(itr->block, 0x00, bytesperclust);
 621
 622         itr->dent = (dir_entry *)itr->block;
 623         itr->last_cluster = 1;
 624         itr->remaining = bytesperclust / sizeof(dir_entry) - 1;
 625
 626         return 0;
 627 }
 628
 629 /*
 630  * Set empty cluster from 'entry' to the end of a file
 631  */
 632 static int clear_fatent(fsdata *mydata, __u32 entry)
 633 {
 634         __u32 fat_val;
 635
 636         while (!CHECK_CLUST(entry, mydata->fatsize)) {
 637                 fat_val = get_fatent(mydata, entry);
 638                 if (fat_val != 0)
 639                         set_fatent_value(mydata, entry, 0);
 640                 else
 641                         break;
 642
 643                 entry = fat_val;
 644         }
 645
 646         /* Flush fat buffer */
 647         if (flush_dirty_fat_buffer(mydata) < 0)
 648                 return -1;
 649
 650         return 0;
 651 }
 652
 653 /*
 654  * Set start cluster in directory entry
 655  */
 656 static void set_start_cluster(const fsdata *mydata, dir_entry *dentptr,
 657                               __u32 start_cluster)
 658 {
 659         if (mydata->fatsize == 32)
 660                 dentptr->starthi =
 661                         cpu_to_le16((start_cluster & 0xffff0000) >> 16);
 662         dentptr->start = cpu_to_le16(start_cluster & 0xffff);
 663 }
 664
 665 /*
 666  * Check whether adding a file makes the file system to
 667  * exceed the size of the block device
 668  * Return -1 when overflow occurs, otherwise return 0
 669  */
 670 static int check_overflow(fsdata *mydata, __u32 clustnum, loff_t size)
 671 {
 672         __u32 startsect, sect_num, offset;
 673
 674         if (clustnum > 0)
 675                 startsect = clust_to_sect(mydata, clustnum);
 676         else
 677                 startsect = mydata->rootdir_sect;
 678
 679         sect_num = div_u64_rem(size, mydata->sect_size, &offset);
 680
 681         if (offset != 0)
 682                 sect_num++;
 683
 684         if (startsect + sect_num > total_sector)
 685                 return -1;
 686         return 0;
 687 }
 688
 689 /*
 690  * Write at most 'maxsize' bytes from 'buffer' into
 691  * the file associated with 'dentptr'
 692  * Update the number of bytes written in *gotsize and return 0
 693  * or return -1 on fatal errors.
 694  */
 695 static int
 696 set_contents(fsdata *mydata, dir_entry *dentptr, loff_t pos, __u8 *buffer,
 697              loff_t maxsize, loff_t *gotsize)
 698 {
 699         unsigned int bytesperclust = mydata->clust_size * mydata->sect_size;
 700         __u32 curclust = START(dentptr);
 701         __u32 endclust = 0, newclust = 0;
 702         u64 cur_pos, filesize;
 703         loff_t offset, actsize, wsize;
 704
 705         *gotsize = 0;
 706         filesize = pos + maxsize;
 707
 708         debug("%llu bytes\n", filesize);
 709
 710         if (!filesize) {
 711                 if (!curclust)
 712                         return 0;
 713                 if (!CHECK_CLUST(curclust, mydata->fatsize) ||
 714                     IS_LAST_CLUST(curclust, mydata->fatsize)) {
 715                         clear_fatent(mydata, curclust);
 716                         set_start_cluster(mydata, dentptr, 0);
 717                         return 0;
 718                 }
 719                 debug("curclust: 0x%x\n", curclust);
 720                 debug("Invalid FAT entry\n");
 721                 return -1;
 722         }
 723
 724         if (!curclust) {
 725                 assert(pos == 0);
 726                 goto set_clusters;
 727         }
 728
 729         /* go to cluster at pos */
 730         cur_pos = bytesperclust;
 731         while (1) {
 732                 if (pos <= cur_pos)
 733                         break;
 734                 if (IS_LAST_CLUST(curclust, mydata->fatsize))
 735                         break;
 736
 737                 newclust = get_fatent(mydata, curclust);
 738                 if (!IS_LAST_CLUST(newclust, mydata->fatsize) &&
 739                     CHECK_CLUST(newclust, mydata->fatsize)) {
 740                         debug("curclust: 0x%x\n", curclust);
 741                         debug("Invalid FAT entry\n");
 742                         return -1;
 743                 }
 744
 745                 cur_pos += bytesperclust;
 746                 curclust = newclust;
 747         }
 748         if (IS_LAST_CLUST(curclust, mydata->fatsize)) {
 749                 assert(pos == cur_pos);
 750                 goto set_clusters;
 751         }
 752
 753         assert(pos < cur_pos);
 754         cur_pos -= bytesperclust;
 755
 756         /* overwrite */
 757         assert(IS_LAST_CLUST(curclust, mydata->fatsize) ||
 758                !CHECK_CLUST(curclust, mydata->fatsize));
 759
 760         while (1) {
 761                 /* search for allocated consecutive clusters */
 762                 actsize = bytesperclust;
 763                 endclust = curclust;
 764                 while (1) {
 765                         if (filesize <= (cur_pos + actsize))
 766                                 break;
 767
 768                         newclust = get_fatent(mydata, endclust);
 769
 770                         if (IS_LAST_CLUST(newclust, mydata->fatsize))
 771                                 break;
 772                         if (CHECK_CLUST(newclust, mydata->fatsize)) {
 773                                 debug("curclust: 0x%x\n", curclust);
 774                                 debug("Invalid FAT entry\n");
 775                                 return -1;
 776                         }
 777
 778                         actsize += bytesperclust;
 779                         endclust = newclust;
 780                 }
 781
 782                 /* overwrite to <curclust..endclust> */
 783                 if (pos < cur_pos)
 784                         offset = 0;
 785                 else
 786                         offset = pos - cur_pos;
 787                 wsize = min(cur_pos + actsize, filesize) - pos;
 788                 if (get_set_cluster(mydata, curclust, offset,
 789                                     buffer, wsize, &actsize)) {
 790                         printf("Error get-and-setting cluster\n");
 791                         return -1;
 792                 }
 793                 buffer += wsize;
 794                 *gotsize += wsize;
 795                 cur_pos += offset + wsize;
 796
 797                 if (filesize <= cur_pos)
 798                         break;
 799
 800                 /* CHECK: newclust = get_fatent(mydata, endclust); */
 801
 802                 if (IS_LAST_CLUST(newclust, mydata->fatsize))
 803                         /* no more clusters */
 804                         break;
 805
 806                 curclust = newclust;
 807         }
 808
 809         if (filesize <= cur_pos) {
 810                 /* no more write */
 811                 newclust = get_fatent(mydata, endclust);
 812                 if (!IS_LAST_CLUST(newclust, mydata->fatsize)) {
 813                         /* truncate the rest */
 814                         clear_fatent(mydata, newclust);
 815
 816                         /* Mark end of file in FAT */
 817                         if (mydata->fatsize == 12)
 818                                 newclust = 0xfff;
 819                         else if (mydata->fatsize == 16)
 820                                 newclust = 0xffff;
 821                         else if (mydata->fatsize == 32)
 822                                 newclust = 0xfffffff;
 823                         set_fatent_value(mydata, endclust, newclust);
 824                 }
 825
 826                 return 0;
 827         }
 828
 829         curclust = endclust;
 830         filesize -= cur_pos;
 831         assert(!do_div(cur_pos, bytesperclust));
 832
 833 set_clusters:
 834         /* allocate and write */
 835         assert(!pos);
 836
 837         /* Assure that curclust is valid */
 838         if (!curclust) {
 839                 curclust = find_empty_cluster(mydata);
 840                 set_start_cluster(mydata, dentptr, curclust);
 841         } else {
 842                 newclust = get_fatent(mydata, curclust);
 843
 844                 if (IS_LAST_CLUST(newclust, mydata->fatsize)) {
 845                         newclust = determine_fatent(mydata, curclust);
 846                         set_fatent_value(mydata, curclust, newclust);
 847                         curclust = newclust;
 848                 } else {
 849                         debug("error: something wrong\n");
 850                         return -1;
 851                 }
 852         }
 853
 854         /* TODO: already partially written */
 855         if (check_overflow(mydata, curclust, filesize)) {
 856                 printf("Error: no space left: %llu\n", filesize);
 857                 return -1;
 858         }
 859
 860         actsize = bytesperclust;
 861         endclust = curclust;
 862         do {
 863                 /* search for consecutive clusters */
 864                 while (actsize < filesize) {
 865                         newclust = determine_fatent(mydata, endclust);
 866
 867                         if ((newclust - 1) != endclust)
 868                                 /* write to <curclust..endclust> */
 869                                 goto getit;
 870
 871                         if (CHECK_CLUST(newclust, mydata->fatsize)) {
 872                                 debug("newclust: 0x%x\n", newclust);
 873                                 debug("Invalid FAT entry\n");
 874                                 return 0;
 875                         }
 876                         endclust = newclust;
 877                         actsize += bytesperclust;
 878                 }
 879
 880                 /* set remaining bytes */
 881                 actsize = filesize;
 882                 if (set_cluster(mydata, curclust, buffer, (u32)actsize) != 0) {
 883                         debug("error: writing cluster\n");
 884                         return -1;
 885                 }
 886                 *gotsize += actsize;
 887
 888                 /* Mark end of file in FAT */
 889                 if (mydata->fatsize == 12)
 890                         newclust = 0xfff;
 891                 else if (mydata->fatsize == 16)
 892                         newclust = 0xffff;
 893                 else if (mydata->fatsize == 32)
 894                         newclust = 0xfffffff;
 895                 set_fatent_value(mydata, endclust, newclust);
 896
 897                 return 0;
 898 getit:
 899                 if (set_cluster(mydata, curclust, buffer, (u32)actsize) != 0) {
 900                         debug("error: writing cluster\n");
 901                         return -1;
 902                 }
 903                 *gotsize += actsize;
 904                 filesize -= actsize;
 905                 buffer += actsize;
 906
 907                 if (CHECK_CLUST(newclust, mydata->fatsize)) {
 908                         debug("newclust: 0x%x\n", newclust);
 909                         debug("Invalid FAT entry\n");
 910                         return 0;
 911                 }
 912                 actsize = bytesperclust;
 913                 curclust = endclust = newclust;
 914         } while (1);
 915
 916         return 0;
 917 }
 918
 919 /*
 920  * Fill dir_entry
 921  */
 922 static void fill_dentry(fsdata *mydata, dir_entry *dentptr,
 923         const char *filename, __u32 start_cluster, __u32 size, __u8 attr)
 924 {
 925         set_start_cluster(mydata, dentptr, start_cluster);
 926         dentptr->size = cpu_to_le32(size);
 927
 928         dentptr->attr = attr;
 929
 930         set_name(dentptr, filename);
 931 }
 932
 933 /*
 934  * Find a directory entry based on filename or start cluster number
 935  * If the directory entry is not found,
 936  * the new position for writing a directory entry will be returned
 937  */
 938 static dir_entry *find_directory_entry(fat_itr *itr, char *filename)
 939 {
 940         int match = 0;
 941
 942         while (fat_itr_next(itr)) {
 943                 /* check both long and short name: */
 944                 if (!strcasecmp(filename, itr->name))
 945                         match = 1;
 946                 else if (itr->name != itr->s_name &&
 947                          !strcasecmp(filename, itr->s_name))
 948                         match = 1;
 949
 950                 if (!match)
 951                         continue;
 952
 953                 if (itr->dent->name[0] == '\0')
 954                         return NULL;
 955                 else
 956                         return itr->dent;
 957         }
 958
 959         if (!itr->dent && !itr->is_root && flush_dir_table(itr))
 960                 /* indicate that allocating dent failed */
 961                 itr->dent = NULL;
 962
 963         return NULL;
 964 }
 965
 966 static int split_filename(char *filename, char **dirname, char **basename)
 967 {
 968         char *p, *last_slash, *last_slash_cont;
 969
 970 again:
 971         p = filename;
 972         last_slash = NULL;
 973         last_slash_cont = NULL;
 974         while (*p) {
 975                 if (ISDIRDELIM(*p)) {
 976                         last_slash = p;
 977                         last_slash_cont = p;
 978                         /* continuous slashes */
 979                         while (ISDIRDELIM(*p))
 980                                 last_slash_cont = p++;
 981                         if (!*p)
 982                                 break;
 983                 }
 984                 p++;
 985         }
 986
 987         if (last_slash) {
 988                 if (last_slash_cont == (filename + strlen(filename) - 1)) {
 989                         /* remove trailing slashes */
 990                         *last_slash = '\0';
 991                         goto again;
 992                 }
 993
 994                 if (last_slash == filename) {
 995                         /* avoid ""(null) directory */
 996                         *dirname = "/";
 997                 } else {
 998                         *last_slash = '\0';
 999                         *dirname = filename;
1000                 }
1001
1002                 *last_slash_cont = '\0';
1003                 *basename = last_slash_cont + 1;
1004         } else {
1005                 *dirname = "/"; /* root by default */
1006                 *basename = filename;
1007         }
1008
1009         return 0;
1010 }
1011
1012 /**
1013  * normalize_longname() - check long file name and convert to lower case
1014  *
1015  * We assume here that the FAT file system is using an 8bit code page.
1016  * Linux typically uses CP437, EDK2 assumes CP1250.
1017  *
1018  * @l_filename: preallocated buffer receiving the normalized name
1019  * @filename:   filename to normalize
1020  * Return:      0 on success, -1 on failure
1021  */
1022 static int normalize_longname(char *l_filename, const char *filename)
1023 {
1024         const char *p, illegal[] = "<>:\"/\\|?*";
1025
1026         if (strlen(filename) >= VFAT_MAXLEN_BYTES)
1027                 return -1;
1028
1029         for (p = filename; *p; ++p) {
1030                 if ((unsigned char)*p < 0x20)
1031                         return -1;
1032                 if (strchr(illegal, *p))
1033                         return -1;
1034         }
1035
1036         strcpy(l_filename, filename);
1037         downcase(l_filename, VFAT_MAXLEN_BYTES);
1038
1039         return 0;
1040 }
1041
1042 int file_fat_write_at(const char *filename, loff_t pos, void *buffer,
1043                       loff_t size, loff_t *actwrite)
1044 {
1045         dir_entry *retdent;
1046         fsdata datablock = { .fatbuf = NULL, };
1047         fsdata *mydata = &datablock;
1048         fat_itr *itr = NULL;
1049         int ret = -1;
1050         char *filename_copy, *parent, *basename;
1051         char l_filename[VFAT_MAXLEN_BYTES];
1052
1053         debug("writing %s\n", filename);
1054
1055         filename_copy = strdup(filename);
1056         if (!filename_copy)
1057                 return -ENOMEM;
1058
1059         split_filename(filename_copy, &parent, &basename);
1060         if (!strlen(basename)) {
1061                 ret = -EINVAL;
1062                 goto exit;
1063         }
1064
1065         filename = basename;
1066         if (normalize_longname(l_filename, filename)) {
1067                 printf("FAT: illegal filename (%s)\n", filename);
1068                 ret = -EINVAL;
1069                 goto exit;
1070         }
1071
1072         itr = malloc_cache_aligned(sizeof(fat_itr));
1073         if (!itr) {
1074                 ret = -ENOMEM;
1075                 goto exit;
1076         }
1077
1078         ret = fat_itr_root(itr, &datablock);
1079         if (ret)
1080                 goto exit;
1081
1082         total_sector = datablock.total_sect;
1083
1084         ret = fat_itr_resolve(itr, parent, TYPE_DIR);
1085         if (ret) {
1086                 printf("%s: doesn't exist (%d)\n", parent, ret);
1087                 goto exit;
1088         }
1089
1090         retdent = find_directory_entry(itr, l_filename);
1091
1092         if (retdent) {
1093                 if (fat_itr_isdir(itr)) {
1094                         ret = -EISDIR;
1095                         goto exit;
1096                 }
1097
1098                 /* A file exists */
1099                 if (pos == -1)
1100                         /* Append to the end */
1101                         pos = FAT2CPU32(retdent->size);
1102                 if (pos > retdent->size) {
1103                         /* No hole allowed */
1104                         ret = -EINVAL;
1105                         goto exit;
1106                 }
1107
1108                 /* Update file size in a directory entry */
1109                 retdent->size = cpu_to_le32(pos + size);
1110         } else {
1111                 /* Create a new file */
1112
1113                 if (itr->is_root) {
1114                         /* root dir cannot have "." or ".." */
1115                         if (!strcmp(l_filename, ".") ||
1116                             !strcmp(l_filename, "..")) {
1117                                 ret = -EINVAL;
1118                                 goto exit;
1119                         }
1120                 }
1121
1122                 if (!itr->dent) {
1123                         printf("Error: allocating new dir entry\n");
1124                         ret = -EIO;
1125                         goto exit;
1126                 }
1127
1128                 if (pos) {
1129                         /* No hole allowed */
1130                         ret = -EINVAL;
1131                         goto exit;
1132                 }
1133
1134                 memset(itr->dent, 0, sizeof(*itr->dent));
1135
1136                 /* Set short name to set alias checksum field in dir_slot */
1137                 set_name(itr->dent, filename);
1138                 if (fill_dir_slot(itr, filename)) {
1139                         ret = -EIO;
1140                         goto exit;
1141                 }
1142
1143                 /* Set attribute as archive for regular file */
1144                 fill_dentry(itr->fsdata, itr->dent, filename, 0, size, 0x20);
1145
1146                 retdent = itr->dent;
1147         }
1148
1149         ret = set_contents(mydata, retdent, pos, buffer, size, actwrite);
1150         if (ret < 0) {
1151                 printf("Error: writing contents\n");
1152                 ret = -EIO;
1153                 goto exit;
1154         }
1155         debug("attempt to write 0x%llx bytes\n", *actwrite);
1156
1157         /* Flush fat buffer */
1158         ret = flush_dirty_fat_buffer(mydata);
1159         if (ret) {
1160                 printf("Error: flush fat buffer\n");
1161                 ret = -EIO;
1162                 goto exit;
1163         }
1164
1165         /* Write directory table to device */
1166         ret = set_cluster(mydata, itr->clust, itr->block,
1167                           mydata->clust_size * mydata->sect_size);
1168         if (ret) {
1169                 printf("Error: writing directory entry\n");
1170                 ret = -EIO;
1171         }
1172
1173 exit:
1174         free(filename_copy);
1175         free(mydata->fatbuf);
1176         free(itr);
1177         return ret;
1178 }
1179
1180 int file_fat_write(const char *filename, void *buffer, loff_t offset,
1181                    loff_t maxsize, loff_t *actwrite)
1182 {
1183         return file_fat_write_at(filename, offset, buffer, maxsize, actwrite);
1184 }
1185
1186 static int fat_dir_entries(fat_itr *itr)
1187 {
1188         fat_itr *dirs;
1189         fsdata fsdata = { .fatbuf = NULL, }, *mydata = &fsdata;
1190                                                 /* for FATBUFSIZE */
1191         int count;
1192
1193         dirs = malloc_cache_aligned(sizeof(fat_itr));
1194         if (!dirs) {
1195                 debug("Error: allocating memory\n");
1196                 count = -ENOMEM;
1197                 goto exit;
1198         }
1199
1200         /* duplicate fsdata */
1201         fat_itr_child(dirs, itr);
1202         fsdata = *dirs->fsdata;
1203
1204         /* allocate local fat buffer */
1205         fsdata.fatbuf = malloc_cache_aligned(FATBUFSIZE);
1206         if (!fsdata.fatbuf) {
1207                 debug("Error: allocating memory\n");
1208                 count = -ENOMEM;
1209                 goto exit;
1210         }
1211         fsdata.fatbufnum = -1;
1212         dirs->fsdata = &fsdata;
1213
1214         for (count = 0; fat_itr_next(dirs); count++)
1215                 ;
1216
1217 exit:
1218         free(fsdata.fatbuf);
1219         free(dirs);
1220         return count;
1221 }
1222
1223 static int delete_dentry(fat_itr *itr)
1224 {
1225         fsdata *mydata = itr->fsdata;
1226         dir_entry *dentptr = itr->dent;
1227
1228         /* free cluster blocks */
1229         clear_fatent(mydata, START(dentptr));
1230         if (flush_dirty_fat_buffer(mydata) < 0) {
1231                 printf("Error: flush fat buffer\n");
1232                 return -EIO;
1233         }
1234
1235         /*
1236          * update a directory entry
1237          * TODO:
1238          *  - long file name support
1239          *  - find and mark the "new" first invalid entry as name[0]=0x00
1240          */
1241         memset(dentptr, 0, sizeof(*dentptr));
1242         dentptr->name[0] = 0xe5;
1243
1244         if (set_cluster(mydata, itr->clust, itr->block,
1245                         mydata->clust_size * mydata->sect_size) != 0) {
1246                 printf("error: writing directory entry\n");
1247                 return -EIO;
1248         }
1249
1250         return 0;
1251 }
1252
1253 int fat_unlink(const char *filename)
1254 {
1255         fsdata fsdata = { .fatbuf = NULL, };
1256         fat_itr *itr = NULL;
1257         int n_entries, ret;
1258         char *filename_copy, *dirname, *basename;
1259
1260         filename_copy = strdup(filename);
1261         if (!filename_copy) {
1262                 printf("Error: allocating memory\n");
1263                 ret = -ENOMEM;
1264                 goto exit;
1265         }
1266         split_filename(filename_copy, &dirname, &basename);
1267
1268         if (!strcmp(dirname, "/") && !strcmp(basename, "")) {
1269                 printf("Error: cannot remove root\n");
1270                 ret = -EINVAL;
1271                 goto exit;
1272         }
1273
1274         itr = malloc_cache_aligned(sizeof(fat_itr));
1275         if (!itr) {
1276                 printf("Error: allocating memory\n");
1277                 ret = -ENOMEM;
1278                 goto exit;
1279         }
1280
1281         ret = fat_itr_root(itr, &fsdata);
1282         if (ret)
1283                 goto exit;
1284
1285         total_sector = fsdata.total_sect;
1286
1287         ret = fat_itr_resolve(itr, dirname, TYPE_DIR);
1288         if (ret) {
1289                 printf("%s: doesn't exist (%d)\n", dirname, ret);
1290                 ret = -ENOENT;
1291                 goto exit;
1292         }
1293
1294         if (!find_directory_entry(itr, basename)) {
1295                 printf("%s: doesn't exist\n", basename);
1296                 ret = -ENOENT;
1297                 goto exit;
1298         }
1299
1300         if (fat_itr_isdir(itr)) {
1301                 n_entries = fat_dir_entries(itr);
1302                 if (n_entries < 0) {
1303                         ret = n_entries;
1304                         goto exit;
1305                 }
1306                 if (n_entries > 2) {
1307                         printf("Error: directory is not empty: %d\n",
1308                                n_entries);
1309                         ret = -EINVAL;
1310                         goto exit;
1311                 }
1312         }
1313
1314         ret = delete_dentry(itr);
1315
1316 exit:
1317         free(fsdata.fatbuf);
1318         free(itr);
1319         free(filename_copy);
1320
1321         return ret;
1322 }
1323
1324 int fat_mkdir(const char *new_dirname)
1325 {
1326         dir_entry *retdent;
1327         fsdata datablock = { .fatbuf = NULL, };
1328         fsdata *mydata = &datablock;
1329         fat_itr *itr = NULL;
1330         char *dirname_copy, *parent, *dirname;
1331         char l_dirname[VFAT_MAXLEN_BYTES];
1332         int ret = -1;
1333         loff_t actwrite;
1334         unsigned int bytesperclust;
1335         dir_entry *dotdent = NULL;
1336
1337         dirname_copy = strdup(new_dirname);
1338         if (!dirname_copy)
1339                 goto exit;
1340
1341         split_filename(dirname_copy, &parent, &dirname);
1342         if (!strlen(dirname)) {
1343                 ret = -EINVAL;
1344                 goto exit;
1345         }
1346
1347         if (normalize_longname(l_dirname, dirname)) {
1348                 printf("FAT: illegal filename (%s)\n", dirname);
1349                 ret = -EINVAL;
1350                 goto exit;
1351         }
1352
1353         itr = malloc_cache_aligned(sizeof(fat_itr));
1354         if (!itr) {
1355                 ret = -ENOMEM;
1356                 goto exit;
1357         }
1358
1359         ret = fat_itr_root(itr, &datablock);
1360         if (ret)
1361                 goto exit;
1362
1363         total_sector = datablock.total_sect;
1364
1365         ret = fat_itr_resolve(itr, parent, TYPE_DIR);
1366         if (ret) {
1367                 printf("%s: doesn't exist (%d)\n", parent, ret);
1368                 goto exit;
1369         }
1370
1371         retdent = find_directory_entry(itr, l_dirname);
1372
1373         if (retdent) {
1374                 printf("%s: already exists\n", l_dirname);
1375                 ret = -EEXIST;
1376                 goto exit;
1377         } else {
1378                 if (itr->is_root) {
1379                         /* root dir cannot have "." or ".." */
1380                         if (!strcmp(l_dirname, ".") ||
1381                             !strcmp(l_dirname, "..")) {
1382                                 ret = -EINVAL;
1383                                 goto exit;
1384                         }
1385                 }
1386
1387                 if (!itr->dent) {
1388                         printf("Error: allocating new dir entry\n");
1389                         ret = -EIO;
1390                         goto exit;
1391                 }
1392
1393                 memset(itr->dent, 0, sizeof(*itr->dent));
1394
1395                 /* Set short name to set alias checksum field in dir_slot */
1396                 set_name(itr->dent, dirname);
1397                 fill_dir_slot(itr, dirname);
1398
1399                 /* Set attribute as archive for regular file */
1400                 fill_dentry(itr->fsdata, itr->dent, dirname, 0, 0,
1401                             ATTR_DIR | ATTR_ARCH);
1402
1403                 retdent = itr->dent;
1404         }
1405
1406         /* Default entries */
1407         bytesperclust = mydata->clust_size * mydata->sect_size;
1408         dotdent = malloc_cache_aligned(bytesperclust);
1409         if (!dotdent) {
1410                 ret = -ENOMEM;
1411                 goto exit;
1412         }
1413         memset(dotdent, 0, bytesperclust);
1414
1415         memcpy(dotdent[0].name, ".       ", 8);
1416         memcpy(dotdent[0].ext, "   ", 3);
1417         dotdent[0].attr = ATTR_DIR | ATTR_ARCH;
1418
1419         memcpy(dotdent[1].name, "..      ", 8);
1420         memcpy(dotdent[1].ext, "   ", 3);
1421         dotdent[1].attr = ATTR_DIR | ATTR_ARCH;
1422         set_start_cluster(mydata, &dotdent[1], itr->start_clust);
1423
1424         ret = set_contents(mydata, retdent, 0, (__u8 *)dotdent,
1425                            bytesperclust, &actwrite);
1426         if (ret < 0) {
1427                 printf("Error: writing contents\n");
1428                 goto exit;
1429         }
1430         /* Write twice for "." */
1431         set_start_cluster(mydata, &dotdent[0], START(retdent));
1432         ret = set_contents(mydata, retdent, 0, (__u8 *)dotdent,
1433                            bytesperclust, &actwrite);
1434         if (ret < 0) {
1435                 printf("Error: writing contents\n");
1436                 goto exit;
1437         }
1438
1439         /* Flush fat buffer */
1440         ret = flush_dirty_fat_buffer(mydata);
1441         if (ret) {
1442                 printf("Error: flush fat buffer\n");
1443                 goto exit;
1444         }
1445
1446         /* Write directory table to device */
1447         ret = set_cluster(mydata, itr->clust, itr->block,
1448                           mydata->clust_size * mydata->sect_size);
1449         if (ret)
1450                 printf("Error: writing directory entry\n");
1451
1452 exit:
1453         free(dirname_copy);
1454         free(mydata->fatbuf);
1455         free(itr);
1456         free(dotdent);
1457         return ret;
1458 }