fsck/fsck.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *   Copyright (C) 2019 Namjae Jeon <linkinjeon@kernel.org>
   4  *   Copyright (C) 2020 Hyunchul Lee <hyc.lee@gmail.com>
   5  */
   6
   7 #include <unistd.h>
   8 #include <stdlib.h>
   9 #include <stdio.h>
  10 #include <getopt.h>
  11 #include <inttypes.h>
  12 #include <string.h>
  13 #include <errno.h>
  14 #include <locale.h>
  15
  16 #include "exfat_ondisk.h"
  17 #include "libexfat.h"
  18 #include "fsck.h"
  19 #include "repair.h"
  20
  21 struct fsck_user_input {
  22         struct exfat_user_input         ei;
  23         enum fsck_ui_options            options;
  24 };
  25
  26 #define EXFAT_MAX_UPCASE_CHARS  0x10000
  27
  28 #ifdef WORDS_BIGENDIAN
  29 typedef __u8    bitmap_t;
  30 #else
  31 typedef __u32   bitmap_t;
  32 #endif
  33
  34 #define BITS_PER        (sizeof(bitmap_t) * 8)
  35 #define BIT_MASK(__c)   (1 << ((__c) % BITS_PER))
  36 #define BIT_ENTRY(__c)  ((__c) / BITS_PER)
  37
  38 #define EXFAT_BITMAP_SIZE(__c_count)    \
  39         (DIV_ROUND_UP(__c_count, BITS_PER) * sizeof(bitmap_t))
  40 #define EXFAT_BITMAP_GET(__bmap, __c)   \
  41                         (((bitmap_t *)(__bmap))[BIT_ENTRY(__c)] & BIT_MASK(__c))
  42 #define EXFAT_BITMAP_SET(__bmap, __c)   \
  43                         (((bitmap_t *)(__bmap))[BIT_ENTRY(__c)] |= \
  44                          BIT_MASK(__c))
  45
  46 #define FSCK_EXIT_NO_ERRORS             0x00
  47 #define FSCK_EXIT_CORRECTED             0x01
  48 #define FSCK_EXIT_NEED_REBOOT           0x02
  49 #define FSCK_EXIT_ERRORS_LEFT           0x04
  50 #define FSCK_EXIT_OPERATION_ERROR       0x08
  51 #define FSCK_EXIT_SYNTAX_ERROR          0x10
  52 #define FSCK_EXIT_USER_CANCEL           0x20
  53 #define FSCK_EXIT_LIBRARY_ERROR         0x80
  54
  55 struct exfat_stat {
  56         long            dir_count;
  57         long            file_count;
  58         long            error_count;
  59         long            fixed_count;
  60 };
  61
  62 struct path_resolve_ctx {
  63         struct exfat_inode      *ancestors[255];
  64         __le16                  utf16_path[PATH_MAX + 2];
  65         char                    local_path[PATH_MAX * MB_LEN_MAX + 1];
  66 };
  67
  68 struct exfat_stat exfat_stat;
  69 struct path_resolve_ctx path_resolve_ctx;
  70
  71 static struct option opts[] = {
  72         {"repair",      no_argument,    NULL,   'r' },
  73         {"repair-yes",  no_argument,    NULL,   'y' },
  74         {"repair-no",   no_argument,    NULL,   'n' },
  75         {"repair-auto", no_argument,    NULL,   'p' },
  76         {"version",     no_argument,    NULL,   'V' },
  77         {"verbose",     no_argument,    NULL,   'v' },
  78         {"help",        no_argument,    NULL,   'h' },
  79         {"?",           no_argument,    NULL,   '?' },
  80         {NULL,          0,              NULL,    0  }
  81 };
  82
  83 static void usage(char *name)
  84 {
  85         fprintf(stderr, "Usage: %s\n", name);
  86         fprintf(stderr, "\t-r | --repair        Repair interactively\n");
  87         fprintf(stderr, "\t-y | --repair-yes    Repair without ask\n");
  88         fprintf(stderr, "\t-n | --repair-no     No repair\n");
  89         fprintf(stderr, "\t-p | --repair-auto   Repair automatically\n");
  90         fprintf(stderr, "\t-a                   Repair automatically\n");
  91         fprintf(stderr, "\t-V | --version       Show version\n");
  92         fprintf(stderr, "\t-v | --verbose       Print debug\n");
  93         fprintf(stderr, "\t-h | --help          Show help\n");
  94
  95         exit(FSCK_EXIT_SYNTAX_ERROR);
  96 }
  97
  98 #define fsck_err(parent, inode, fmt, ...)               \
  99 ({                                                      \
 100                 resolve_path_parent(&path_resolve_ctx,  \
 101                         parent, inode);                 \
 102                 exfat_err("ERROR: %s: " fmt,            \
 103                         path_resolve_ctx.local_path,    \
 104                         ##__VA_ARGS__);                 \
 105 })
 106
 107 static struct exfat_inode *alloc_exfat_inode(__u16 attr)
 108 {
 109         struct exfat_inode *node;
 110         int size;
 111
 112         size = offsetof(struct exfat_inode, name) + NAME_BUFFER_SIZE;
 113         node = (struct exfat_inode *)calloc(1, size);
 114         if (!node) {
 115                 exfat_err("failed to allocate exfat_node\n");
 116                 return NULL;
 117         }
 118
 119         node->parent = NULL;
 120         INIT_LIST_HEAD(&node->children);
 121         INIT_LIST_HEAD(&node->sibling);
 122         INIT_LIST_HEAD(&node->list);
 123
 124         node->last_pclus = EXFAT_EOF_CLUSTER;
 125         node->attr = attr;
 126         if (attr & ATTR_SUBDIR)
 127                 exfat_stat.dir_count++;
 128         else
 129                 exfat_stat.file_count++;
 130         return node;
 131 }
 132
 133 static void free_exfat_inode(struct exfat_inode *node)
 134 {
 135         free(node);
 136 }
 137
 138 static void inode_free_children(struct exfat_inode *dir, bool file_only)
 139 {
 140         struct exfat_inode *node, *i;
 141
 142         list_for_each_entry_safe(node, i, &dir->children, sibling) {
 143                 if (file_only) {
 144                         if (!(node->attr & ATTR_SUBDIR)) {
 145                                 list_del(&node->sibling);
 146                                 free_exfat_inode(node);
 147                         }
 148                 } else {
 149                         list_del(&node->sibling);
 150                         list_del(&node->list);
 151                         free_exfat_inode(node);
 152                 }
 153         }
 154 }
 155
 156 static void inode_free_file_children(struct exfat_inode *dir)
 157 {
 158         inode_free_children(dir, true);
 159 }
 160
 161 /* delete @child and all ancestors that does not have
 162  * children
 163  */
 164 static void inode_free_ancestors(struct exfat_inode *child)
 165 {
 166         struct exfat_inode *parent;
 167
 168         if (!list_empty(&child->children))
 169                 return;
 170
 171         do {
 172                 if (!(child->attr & ATTR_SUBDIR)) {
 173                         exfat_err("not directory.\n");
 174                         return;
 175                 }
 176
 177                 parent = child->parent;
 178                 list_del(&child->sibling);
 179                 free_exfat_inode(child);
 180
 181                 child = parent;
 182         } while (child && list_empty(&child->children));
 183
 184         return;
 185 }
 186
 187 static void free_exfat(struct exfat *exfat)
 188 {
 189         int i;
 190
 191         if (exfat) {
 192                 if (exfat->bs)
 193                         free(exfat->bs);
 194                 if (exfat->alloc_bitmap)
 195                         free(exfat->alloc_bitmap);
 196                 if (exfat->disk_bitmap)
 197                         free(exfat->disk_bitmap);
 198                 for (i = 0; i < 2; i++) {
 199                         if (exfat->buffer_desc[i].buffer)
 200                                 free(exfat->buffer_desc[i].buffer);
 201                         if (exfat->buffer_desc[i].dirty)
 202                                 free(exfat->buffer_desc[i].dirty);
 203                 }
 204                 free(exfat);
 205         }
 206 }
 207
 208 static int init_exfat(struct exfat *exfat, struct pbr *bs)
 209 {
 210         int i;
 211
 212         INIT_LIST_HEAD(&exfat->dir_list);
 213         exfat->bs = bs;
 214         exfat->clus_count = le32_to_cpu(bs->bsx.clu_count);
 215         exfat->clus_size = EXFAT_CLUSTER_SIZE(bs);
 216         exfat->sect_size = EXFAT_SECTOR_SIZE(bs);
 217
 218         /* TODO: bitmap could be very large. */
 219         exfat->alloc_bitmap = (char *)calloc(1,
 220                         EXFAT_BITMAP_SIZE(exfat->clus_count));
 221         if (!exfat->alloc_bitmap) {
 222                 exfat_err("failed to allocate bitmap\n");
 223                 goto err;
 224         }
 225
 226         exfat->disk_bitmap = (char *)malloc(
 227                                 EXFAT_BITMAP_SIZE(exfat->clus_count));
 228         if (!exfat->disk_bitmap) {
 229                 exfat_err("failed to allocate bitmap\n");
 230                 goto err;
 231         }
 232
 233         /* allocate cluster buffers */
 234         for (i = 0; i < 2; i++) {
 235                 exfat->buffer_desc[i].buffer =
 236                         (char *)malloc(exfat->clus_size);
 237                 if (!exfat->buffer_desc[i].buffer)
 238                         goto err;
 239                 exfat->buffer_desc[i].dirty =
 240                         (char *)calloc(
 241                         (exfat->clus_size / exfat->sect_size), 1);
 242                 if (!exfat->buffer_desc[i].dirty)
 243                         goto err;
 244         }
 245         return 0;
 246 err:
 247         free_exfat(exfat);
 248         return -ENOMEM;
 249 }
 250
 251 static void exfat_free_dir_list(struct exfat *exfat)
 252 {
 253         struct exfat_inode *dir, *i;
 254
 255         list_for_each_entry_safe(dir, i, &exfat->dir_list, list) {
 256                 inode_free_file_children(dir);
 257                 list_del(&dir->list);
 258                 free_exfat_inode(dir);
 259         }
 260 }
 261
 262 /*
 263  * get references of ancestors that include @child until the count of
 264  * ancesters is not larger than @count and the count of characters of
 265  * their names is not larger than @max_char_len.
 266  * return true if root is reached.
 267  */
 268 bool get_ancestors(struct exfat_inode *child,
 269                 struct exfat_inode **ancestors, int count,
 270                 int max_char_len,
 271                 int *ancestor_count)
 272 {
 273         struct exfat_inode *dir;
 274         int name_len, char_len;
 275         int root_depth, depth, i;
 276
 277         root_depth = 0;
 278         char_len = 0;
 279         max_char_len += 1;
 280
 281         dir = child;
 282         while (dir) {
 283                 name_len = exfat_utf16_len(dir->name, NAME_BUFFER_SIZE);
 284                 if (char_len + name_len > max_char_len)
 285                         break;
 286
 287                 /* include '/' */
 288                 char_len += name_len + 1;
 289                 root_depth++;
 290
 291                 dir = dir->parent;
 292         }
 293
 294         depth = MIN(root_depth, count);
 295
 296         for (dir = child, i = depth - 1; i >= 0; dir = dir->parent, i--)
 297                 ancestors[i] = dir;
 298
 299         *ancestor_count = depth;
 300         return dir == NULL;
 301 }
 302
 303 static int resolve_path(struct path_resolve_ctx *ctx, struct exfat_inode *child)
 304 {
 305         int depth, i;
 306         int name_len;
 307         __le16 *utf16_path;
 308         static const __le16 utf16_slash = cpu_to_le16(0x002F);
 309         static const __le16 utf16_null = cpu_to_le16(0x0000);
 310         size_t in_size;
 311
 312         ctx->local_path[0] = '\0';
 313
 314         get_ancestors(child,
 315                         ctx->ancestors,
 316                         sizeof(ctx->ancestors) / sizeof(ctx->ancestors[0]),
 317                         PATH_MAX,
 318                         &depth);
 319
 320         utf16_path = ctx->utf16_path;
 321         for (i = 0; i < depth; i++) {
 322                 name_len = exfat_utf16_len(ctx->ancestors[i]->name,
 323                                 NAME_BUFFER_SIZE);
 324                 memcpy((char *)utf16_path, (char *)ctx->ancestors[i]->name,
 325                                 name_len * 2);
 326                 utf16_path += name_len;
 327                 memcpy((char *)utf16_path, &utf16_slash, sizeof(utf16_slash));
 328                 utf16_path++;
 329         }
 330
 331         if (depth > 0)
 332                 utf16_path--;
 333         memcpy((char *)utf16_path, &utf16_null, sizeof(utf16_null));
 334         utf16_path++;
 335
 336         in_size = (utf16_path - ctx->utf16_path) * sizeof(__le16);
 337         return exfat_utf16_dec(ctx->utf16_path, in_size,
 338                                 ctx->local_path, sizeof(ctx->local_path));
 339 }
 340
 341 static int resolve_path_parent(struct path_resolve_ctx *ctx,
 342                         struct exfat_inode *parent, struct exfat_inode *child)
 343 {
 344         int ret;
 345         struct exfat_inode *old;
 346
 347         old = child->parent;
 348         child->parent = parent;
 349
 350         ret = resolve_path(ctx, child);
 351         child->parent = old;
 352         return ret;
 353 }
 354
 355 #define repair_file_ask(iter, inode, code, fmt, ...)    \
 356 ({                                                      \
 357                 resolve_path_parent(&path_resolve_ctx,  \
 358                                 (iter)->parent, inode); \
 359                 exfat_repair_ask((iter)->exfat, code,   \
 360                         "ERROR: %s: " fmt,              \
 361                         path_resolve_ctx.local_path,    \
 362                         ##__VA_ARGS__);                 \
 363 })
 364
 365 static inline bool heap_clus(struct exfat *exfat, clus_t clus)
 366 {
 367         return clus >= EXFAT_FIRST_CLUSTER &&
 368                 (clus - EXFAT_FIRST_CLUSTER) < exfat->clus_count;
 369 }
 370
 371 int get_next_clus(struct exfat *exfat, struct exfat_inode *node,
 372                                 clus_t clus, clus_t *next)
 373 {
 374         off_t offset;
 375
 376         *next = EXFAT_EOF_CLUSTER;
 377
 378         if (!heap_clus(exfat, clus))
 379                 return -EINVAL;
 380
 381         if (node->is_contiguous) {
 382                 *next = clus + 1;
 383                 return 0;
 384         }
 385
 386         offset = (off_t)le32_to_cpu(exfat->bs->bsx.fat_offset) <<
 387                                 exfat->bs->bsx.sect_size_bits;
 388         offset += sizeof(clus_t) * clus;
 389
 390         if (exfat_read(exfat->blk_dev->dev_fd, next, sizeof(*next), offset)
 391                         != sizeof(*next))
 392                 return -EIO;
 393         *next = le32_to_cpu(*next);
 394         return 0;
 395 }
 396
 397 static int set_fat(struct exfat *exfat, clus_t clus, clus_t next_clus)
 398 {
 399         off_t offset;
 400
 401         offset = le32_to_cpu(exfat->bs->bsx.fat_offset) <<
 402                 exfat->bs->bsx.sect_size_bits;
 403         offset += sizeof(clus_t) * clus;
 404
 405         if (exfat_write(exfat->blk_dev->dev_fd, &next_clus, sizeof(next_clus),
 406                         offset) != sizeof(next_clus))
 407                 return -EIO;
 408         return 0;
 409 }
 410
 411 static int check_clus_chain(struct exfat *exfat, struct exfat_inode *node)
 412 {
 413         struct exfat_dentry *stream_de;
 414         clus_t clus, prev, next;
 415         uint64_t count, max_count;
 416
 417         clus = node->first_clus;
 418         prev = EXFAT_EOF_CLUSTER;
 419         count = 0;
 420         max_count = DIV_ROUND_UP(node->size, exfat->clus_size);
 421
 422         if (node->size == 0 && node->first_clus == EXFAT_FREE_CLUSTER)
 423                 return 0;
 424
 425         /* the first cluster is wrong */
 426         if ((node->size == 0 && node->first_clus != EXFAT_FREE_CLUSTER) ||
 427                 (node->size > 0 && !heap_clus(exfat, node->first_clus))) {
 428                 if (repair_file_ask(&exfat->de_iter, node,
 429                         ER_FILE_FIRST_CLUS, "first cluster is wrong"))
 430                         goto truncate_file;
 431                 else
 432                         return -EINVAL;
 433         }
 434
 435         while (clus != EXFAT_EOF_CLUSTER) {
 436                 if (count >= max_count) {
 437                         if (node->is_contiguous)
 438                                 break;
 439                         if (repair_file_ask(&exfat->de_iter, node,
 440                                         ER_FILE_SMALLER_SIZE,
 441                                         "more clusters are allocated. "
 442                                         "truncate to %" PRIu64 " bytes",
 443                                         count * exfat->clus_size))
 444                                 goto truncate_file;
 445                         else
 446                                 return -EINVAL;
 447                 }
 448
 449                 /*
 450                  * This cluster is already allocated. it may be shared with
 451                  * the other file, or there is a loop in cluster chain.
 452                  */
 453                 if (EXFAT_BITMAP_GET(exfat->alloc_bitmap,
 454                                 clus - EXFAT_FIRST_CLUSTER)) {
 455                         if (repair_file_ask(&exfat->de_iter, node,
 456                                         ER_FILE_DUPLICATED_CLUS,
 457                                         "cluster is already allocated for "
 458                                         "the other file. truncated to %"
 459                                         PRIu64 " bytes",
 460                                         count * exfat->clus_size))
 461                                 goto truncate_file;
 462                         else
 463                                 return -EINVAL;
 464                 }
 465
 466                 if (!EXFAT_BITMAP_GET(exfat->disk_bitmap,
 467                                 clus - EXFAT_FIRST_CLUSTER)) {
 468                         if (repair_file_ask(&exfat->de_iter, node,
 469                                         ER_FILE_INVALID_CLUS,
 470                                         "cluster is marked as free. truncate to %" PRIu64 " bytes",
 471                                         count * exfat->clus_size))
 472                                 goto truncate_file;
 473
 474                         else
 475                                 return -EINVAL;
 476                 }
 477
 478                 /* This cluster is allocated or not */
 479                 if (get_next_clus(exfat, node, clus, &next))
 480                         goto truncate_file;
 481                 if (!node->is_contiguous) {
 482                         if (!heap_clus(exfat, next) &&
 483                                         next != EXFAT_EOF_CLUSTER) {
 484                                 if (repair_file_ask(&exfat->de_iter, node,
 485                                                 ER_FILE_INVALID_CLUS,
 486                                                 "broken cluster chain. "
 487                                                 "truncate to %"
 488                                                 PRIu64 " bytes",
 489                                                 count * exfat->clus_size))
 490                                         goto truncate_file;
 491
 492                                 else
 493                                         return -EINVAL;
 494                         }
 495                 }
 496
 497                 count++;
 498                 EXFAT_BITMAP_SET(exfat->alloc_bitmap,
 499                                 clus - EXFAT_FIRST_CLUSTER);
 500                 prev = clus;
 501                 clus = next;
 502         }
 503
 504         if (count < max_count) {
 505                 if (repair_file_ask(&exfat->de_iter, node,
 506                         ER_FILE_LARGER_SIZE, "less clusters are allocated. "
 507                         "truncates to %" PRIu64 " bytes",
 508                         count * exfat->clus_size))
 509                         goto truncate_file;
 510                 else
 511                         return -EINVAL;
 512         }
 513
 514         return 0;
 515 truncate_file:
 516         node->size = count * exfat->clus_size;
 517         if (!heap_clus(exfat, prev))
 518                 node->first_clus = EXFAT_FREE_CLUSTER;
 519
 520         exfat_de_iter_get_dirty(&exfat->de_iter, 1, &stream_de);
 521         if (count * exfat->clus_size <
 522                         le64_to_cpu(stream_de->stream_valid_size))
 523                 stream_de->stream_valid_size = cpu_to_le64(
 524                                 count * exfat->clus_size);
 525         if (!heap_clus(exfat, prev))
 526                 stream_de->stream_start_clu = EXFAT_FREE_CLUSTER;
 527         stream_de->stream_size = cpu_to_le64(
 528                         count * exfat->clus_size);
 529
 530         /* remaining clusters will be freed while FAT is compared with
 531          * alloc_bitmap.
 532          */
 533         if (!node->is_contiguous && heap_clus(exfat, prev))
 534                 return set_fat(exfat, prev, EXFAT_EOF_CLUSTER);
 535         return 1;
 536 }
 537
 538 static bool root_get_clus_count(struct exfat *exfat, struct exfat_inode *node,
 539                                                         clus_t *clus_count)
 540 {
 541         clus_t clus;
 542
 543         clus = node->first_clus;
 544         *clus_count = 0;
 545
 546         do {
 547                 if (!heap_clus(exfat, clus)) {
 548                         exfat_err("/: bad cluster. 0x%x\n", clus);
 549                         return false;
 550                 }
 551
 552                 if (EXFAT_BITMAP_GET(exfat->alloc_bitmap,
 553                                 clus - EXFAT_FIRST_CLUSTER)) {
 554                         exfat_err("/: cluster is already allocated, or "
 555                                 "there is a loop in cluster chain\n");
 556                         return false;
 557                 }
 558
 559                 EXFAT_BITMAP_SET(exfat->alloc_bitmap,
 560                                 clus - EXFAT_FIRST_CLUSTER);
 561
 562                 if (get_next_clus(exfat, node, clus, &clus) != 0) {
 563                         exfat_err("/: broken cluster chain\n");
 564                         return false;
 565                 }
 566
 567                 (*clus_count)++;
 568         } while (clus != EXFAT_EOF_CLUSTER);
 569         return true;
 570 }
 571
 572 static off_t exfat_s2o(struct exfat *exfat, off_t sect)
 573 {
 574         return sect << exfat->bs->bsx.sect_size_bits;
 575 }
 576
 577 off_t exfat_c2o(struct exfat *exfat, unsigned int clus)
 578 {
 579         if (clus < EXFAT_FIRST_CLUSTER)
 580                 return ~0L;
 581
 582         return exfat_s2o(exfat, le32_to_cpu(exfat->bs->bsx.clu_offset) +
 583                                 ((off_t)(clus - EXFAT_FIRST_CLUSTER) <<
 584                                  exfat->bs->bsx.sect_per_clus_bits));
 585 }
 586
 587 static int boot_region_checksum(struct exfat_blk_dev *bd, int bs_offset)
 588 {
 589         void *sect;
 590         unsigned int i;
 591         uint32_t checksum;
 592         int ret = 0;
 593         unsigned int size;
 594
 595         size = bd->sector_size;
 596         sect = malloc(size);
 597         if (!sect)
 598                 return -ENOMEM;
 599
 600         checksum = 0;
 601         for (i = 0; i < 11; i++) {
 602                 if (exfat_read(bd->dev_fd, sect, size,
 603                                 bs_offset * size + i * size) !=
 604                                 (ssize_t)size) {
 605                         exfat_err("failed to read boot region\n");
 606                         ret = -EIO;
 607                         goto out;
 608                 }
 609                 boot_calc_checksum(sect, size, i == 0, &checksum);
 610         }
 611
 612         if (exfat_read(bd->dev_fd, sect, size,
 613                         bs_offset * size + 11 * size) !=
 614                         (ssize_t)size) {
 615                 exfat_err("failed to read a boot checksum sector\n");
 616                 ret = -EIO;
 617                 goto out;
 618         }
 619
 620         for (i = 0; i < size/sizeof(checksum); i++) {
 621                 if (le32_to_cpu(((__le32 *)sect)[i]) != checksum) {
 622                         exfat_err("checksum of boot region is not correct. %#x, but expected %#x\n",
 623                                 le32_to_cpu(((__le32 *)sect)[i]), checksum);
 624                         ret = -EINVAL;
 625                         goto out;
 626                 }
 627         }
 628 out:
 629         free(sect);
 630         return ret;
 631 }
 632
 633 static int exfat_mark_volume_dirty(struct exfat *exfat, bool dirty)
 634 {
 635         uint16_t flags;
 636
 637         if (!(exfat->options & FSCK_OPTS_REPAIR_WRITE))
 638                 return 0;
 639
 640         flags = le16_to_cpu(exfat->bs->bsx.vol_flags);
 641         if (dirty)
 642                 flags |= 0x02;
 643         else
 644                 flags &= ~0x02;
 645
 646         exfat->bs->bsx.vol_flags = cpu_to_le16(flags);
 647         if (exfat_write(exfat->blk_dev->dev_fd, exfat->bs,
 648                         sizeof(struct pbr), 0) != (ssize_t)sizeof(struct pbr)) {
 649                 exfat_err("failed to set VolumeDirty\n");
 650                 return -EIO;
 651         }
 652
 653         if (fsync(exfat->blk_dev->dev_fd) != 0) {
 654                 exfat_err("failed to set VolumeDirty\n");
 655                 return -EIO;
 656         }
 657         return 0;
 658 }
 659
 660 static int read_boot_region(struct exfat_blk_dev *bd, struct pbr **pbr,
 661                 int bs_offset)
 662 {
 663         struct pbr *bs;
 664         int ret = -EINVAL;
 665
 666         *pbr = NULL;
 667         bs = (struct pbr *)malloc(sizeof(struct pbr));
 668         if (!bs) {
 669                 exfat_err("failed to allocate memory\n");
 670                 return -ENOMEM;
 671         }
 672
 673         if (exfat_read(bd->dev_fd, bs, sizeof(*bs),
 674                         bs_offset * bd->sector_size) != (ssize_t)sizeof(*bs)) {
 675                 exfat_err("failed to read a boot sector\n");
 676                 ret = -EIO;
 677                 goto err;
 678         }
 679
 680         if (memcmp(bs->bpb.oem_name, "EXFAT   ", 8) != 0) {
 681                 exfat_err("failed to find exfat file system.\n");
 682                 goto err;
 683         }
 684
 685         ret = boot_region_checksum(bd, bs_offset);
 686         if (ret < 0)
 687                 goto err;
 688
 689         ret = -EINVAL;
 690         if (EXFAT_SECTOR_SIZE(bs) < 512 || EXFAT_SECTOR_SIZE(bs) > 4 * KB) {
 691                 exfat_err("too small or big sector size: %d\n",
 692                                 EXFAT_SECTOR_SIZE(bs));
 693                 goto err;
 694         }
 695
 696         if (EXFAT_CLUSTER_SIZE(bs) > 32 * MB) {
 697                 exfat_err("too big cluster size: %d\n", EXFAT_CLUSTER_SIZE(bs));
 698                 goto err;
 699         }
 700
 701         if (bs->bsx.fs_version[1] != 1 || bs->bsx.fs_version[0] != 0) {
 702                 exfat_err("unsupported exfat version: %d.%d\n",
 703                                 bs->bsx.fs_version[1], bs->bsx.fs_version[0]);
 704                 goto err;
 705         }
 706
 707         if (bs->bsx.num_fats != 1) {
 708                 exfat_err("unsupported FAT count: %d\n", bs->bsx.num_fats);
 709                 goto err;
 710         }
 711
 712         if (le64_to_cpu(bs->bsx.vol_length) * EXFAT_SECTOR_SIZE(bs) >
 713                         bd->size) {
 714                 exfat_err("too large sector count: %" PRIu64 ", expected: %llu\n",
 715                                 le64_to_cpu(bs->bsx.vol_length),
 716                                 bd->num_sectors);
 717                 goto err;
 718         }
 719
 720         if (le32_to_cpu(bs->bsx.clu_count) * EXFAT_CLUSTER_SIZE(bs) >
 721                         bd->size) {
 722                 exfat_err("too large cluster count: %u, expected: %u\n",
 723                                 le32_to_cpu(bs->bsx.clu_count),
 724                                 bd->num_clusters);
 725                 goto err;
 726         }
 727
 728         *pbr = bs;
 729         return 0;
 730 err:
 731         free(bs);
 732         return ret;
 733 }
 734
 735 static int restore_boot_region(struct exfat_blk_dev *bd)
 736 {
 737         int i;
 738         char *sector;
 739         int ret;
 740
 741         sector = malloc(bd->sector_size);
 742         if (!sector)
 743                 return -ENOMEM;
 744
 745         for (i = 0; i < 12; i++) {
 746                 if (exfat_read(bd->dev_fd, sector, bd->sector_size,
 747                                 BACKUP_BOOT_SEC_IDX * bd->sector_size +
 748                                 i * bd->sector_size) !=
 749                                 (ssize_t)bd->sector_size) {
 750                         ret = -EIO;
 751                         goto free_sector;
 752                 }
 753                 if (i == 0)
 754                         ((struct pbr *)sector)->bsx.perc_in_use = 0xff;
 755
 756                 if (exfat_write(bd->dev_fd, sector, bd->sector_size,
 757                                 BOOT_SEC_IDX * bd->sector_size +
 758                                 i * bd->sector_size) !=
 759                                 (ssize_t)bd->sector_size) {
 760                         ret = -EIO;
 761                         goto free_sector;
 762                 }
 763         }
 764
 765         if (fsync(bd->dev_fd)) {
 766                 ret = -EIO;
 767                 goto free_sector;
 768         }
 769         ret = 0;
 770
 771 free_sector:
 772         free(sector);
 773         return ret;
 774 }
 775
 776 static int exfat_boot_region_check(struct exfat *exfat, struct pbr **bs)
 777 {
 778         int ret;
 779
 780         ret = read_boot_region(exfat->blk_dev, bs, BOOT_SEC_IDX);
 781         if (ret == -EINVAL && exfat_repair_ask(exfat, ER_BS_BOOT_REGION,
 782                                 "boot region is corrupted. try to restore the region from backup"
 783                                 )) {
 784                 ret = read_boot_region(exfat->blk_dev, bs, BACKUP_BOOT_SEC_IDX);
 785                 if (ret < 0) {
 786                         exfat_err("backup boot region is also corrupted\n");
 787                         return ret;
 788                 }
 789                 ret = restore_boot_region(exfat->blk_dev);
 790                 if (ret < 0) {
 791                         exfat_err("failed to restore boot region from backup\n");
 792                         free(*bs);
 793                         *bs = NULL;
 794                         return ret;
 795                 }
 796         }
 797         return ret;
 798 }
 799
 800 static void dentry_calc_checksum(struct exfat_dentry *dentry,
 801                                 __le16 *checksum, bool primary)
 802 {
 803         unsigned int i;
 804         uint8_t *bytes;
 805
 806         bytes = (uint8_t *)dentry;
 807
 808         *checksum = ((*checksum << 15) | (*checksum >> 1)) + bytes[0];
 809         *checksum = ((*checksum << 15) | (*checksum >> 1)) + bytes[1];
 810
 811         i = primary ? 4 : 2;
 812         for (; i < sizeof(*dentry); i++) {
 813                 *checksum = ((*checksum << 15) | (*checksum >> 1)) + bytes[i];
 814         }
 815 }
 816
 817 static __le16 file_calc_checksum(struct exfat_de_iter *iter)
 818 {
 819         __le16 checksum;
 820         struct exfat_dentry *file_de, *de;
 821         int i;
 822
 823         checksum = 0;
 824         exfat_de_iter_get(iter, 0, &file_de);
 825
 826         dentry_calc_checksum(file_de, &checksum, true);
 827         for (i = 1; i <= file_de->file_num_ext; i++) {
 828                 exfat_de_iter_get(iter, i, &de);
 829                 dentry_calc_checksum(de, &checksum, false);
 830         }
 831
 832         return checksum;
 833 }
 834
 835 /*
 836  * return 0 if there are no errors, or 1 if errors are fixed, or
 837  * an error code
 838  */
 839 static int check_inode(struct exfat_de_iter *iter, struct exfat_inode *node)
 840 {
 841         struct exfat *exfat = iter->exfat;
 842         struct exfat_dentry *dentry;
 843         int ret = 0;
 844         uint16_t checksum;
 845         bool valid = true;
 846
 847         ret = check_clus_chain(exfat, node);
 848         if (ret < 0)
 849                 return ret;
 850
 851         if (node->size > le32_to_cpu(exfat->bs->bsx.clu_count) *
 852                                 (uint64_t)exfat->clus_size) {
 853                 fsck_err(iter->parent, node,
 854                         "size %" PRIu64 " is greater than cluster heap\n",
 855                         node->size);
 856                 valid = false;
 857         }
 858
 859         if (node->size == 0 && node->is_contiguous) {
 860                 if (repair_file_ask(iter, node, ER_FILE_ZERO_NOFAT,
 861                                 "empty, but has no Fat chain\n")) {
 862                         exfat_de_iter_get_dirty(iter, 1, &dentry);
 863                         dentry->stream_flags &= ~EXFAT_SF_CONTIGUOUS;
 864                         ret = 1;
 865                 } else
 866                         valid = false;
 867         }
 868
 869         if ((node->attr & ATTR_SUBDIR) &&
 870                         node->size % exfat->clus_size != 0) {
 871                 fsck_err(iter->parent, node,
 872                         "directory size %" PRIu64 " is not divisible by %d\n",
 873                         node->size, exfat->clus_size);
 874                 valid = false;
 875         }
 876
 877         checksum = file_calc_checksum(iter);
 878         exfat_de_iter_get(iter, 0, &dentry);
 879         if (checksum != le16_to_cpu(dentry->file_checksum)) {
 880                 if (repair_file_ask(iter, node, ER_DE_CHECKSUM,
 881                                 "the checksum of a file is wrong")) {
 882                         exfat_de_iter_get_dirty(iter, 0, &dentry);
 883                         dentry->file_checksum = cpu_to_le16(checksum);
 884                         ret = 1;
 885                 } else
 886                         valid = false;
 887         }
 888
 889         return valid ? ret : -EINVAL;
 890 }
 891
 892 static int read_file_dentries(struct exfat_de_iter *iter,
 893                         struct exfat_inode **new_node, int *skip_dentries)
 894 {
 895         struct exfat_dentry *file_de, *stream_de, *name_de;
 896         struct exfat_inode *node;
 897         int i, ret;
 898
 899         /* TODO: mtime, atime, ... */
 900
 901         ret = exfat_de_iter_get(iter, 0, &file_de);
 902         if (ret || file_de->type != EXFAT_FILE) {
 903                 exfat_err("failed to get file dentry. %d\n", ret);
 904                 return -EINVAL;
 905         }
 906         ret = exfat_de_iter_get(iter, 1, &stream_de);
 907         if (ret || stream_de->type != EXFAT_STREAM) {
 908                 exfat_err("failed to get stream dentry. %d\n", ret);
 909                 return -EINVAL;
 910         }
 911
 912         *new_node = NULL;
 913         node = alloc_exfat_inode(le16_to_cpu(file_de->file_attr));
 914         if (!node)
 915                 return -ENOMEM;
 916
 917         if (file_de->file_num_ext < 2) {
 918                 exfat_err("too few secondary count. %d\n",
 919                                 file_de->file_num_ext);
 920                 free_exfat_inode(node);
 921                 return -EINVAL;
 922         }
 923
 924         for (i = 2; i <= file_de->file_num_ext; i++) {
 925                 ret = exfat_de_iter_get(iter, i, &name_de);
 926                 if (ret || name_de->type != EXFAT_NAME) {
 927                         exfat_err("failed to get name dentry. %d\n", ret);
 928                         ret = -EINVAL;
 929                         goto err;
 930                 }
 931
 932                 memcpy(node->name +
 933                         (i-2) * ENTRY_NAME_MAX, name_de->name_unicode,
 934                         sizeof(name_de->name_unicode));
 935         }
 936
 937         node->first_clus = le32_to_cpu(stream_de->stream_start_clu);
 938         node->is_contiguous =
 939                 ((stream_de->stream_flags & EXFAT_SF_CONTIGUOUS) != 0);
 940         node->size = le64_to_cpu(stream_de->stream_size);
 941
 942         if (node->size < le64_to_cpu(stream_de->stream_valid_size)) {
 943                 if (repair_file_ask(iter, node, ER_FILE_VALID_SIZE,
 944                         "valid size %" PRIu64 " greater than size %" PRIu64,
 945                         le64_to_cpu(stream_de->stream_valid_size),
 946                         node->size)) {
 947                         exfat_de_iter_get_dirty(iter, 1, &stream_de);
 948                         stream_de->stream_valid_size =
 949                                         stream_de->stream_size;
 950                 } else {
 951                         ret = -EINVAL;
 952                         goto err;
 953                 }
 954         }
 955
 956         *skip_dentries = (file_de->file_num_ext + 1);
 957         *new_node = node;
 958         return 0;
 959 err:
 960         *skip_dentries = 0;
 961         *new_node = NULL;
 962         free_exfat_inode(node);
 963         return ret;
 964 }
 965
 966 static int read_file(struct exfat_de_iter *de_iter,
 967                 struct exfat_inode **new_node, int *dentry_count)
 968 {
 969         struct exfat_inode *node;
 970         int ret;
 971
 972         *new_node = NULL;
 973
 974         ret = read_file_dentries(de_iter, &node, dentry_count);
 975         if (ret)
 976                 return ret;
 977
 978         ret = check_inode(de_iter, node);
 979         if (ret < 0) {
 980                 free_exfat_inode(node);
 981                 return -EINVAL;
 982         }
 983
 984         *new_node = node;
 985         return ret;
 986 }
 987
 988 static bool read_volume_label(struct exfat_de_iter *iter)
 989 {
 990         struct exfat *exfat;
 991         struct exfat_dentry *dentry;
 992         __le16 disk_label[VOLUME_LABEL_MAX_LEN];
 993
 994         exfat = iter->exfat;
 995         if (exfat_de_iter_get(iter, 0, &dentry))
 996                 return false;
 997
 998         if (dentry->vol_char_cnt == 0)
 999                 return true;
1000
1001         if (dentry->vol_char_cnt > VOLUME_LABEL_MAX_LEN) {
1002                 exfat_err("too long label. %d\n", dentry->vol_char_cnt);
1003                 return false;
1004         }
1005
1006         memcpy(disk_label, dentry->vol_label, sizeof(disk_label));
1007         if (exfat_utf16_dec(disk_label, dentry->vol_char_cnt*2,
1008                 exfat->volume_label, sizeof(exfat->volume_label)) < 0) {
1009                 exfat_err("failed to decode volume label\n");
1010                 return false;
1011         }
1012
1013         exfat_info("volume label [%s]\n", exfat->volume_label);
1014         return true;
1015 }
1016
1017 static void exfat_bitmap_set_range(struct exfat *exfat,
1018                         clus_t start_clus, clus_t count)
1019 {
1020         clus_t clus;
1021
1022         if (!heap_clus(exfat, start_clus) ||
1023                 !heap_clus(exfat, start_clus + count))
1024                 return;
1025
1026         clus = start_clus;
1027         while (clus < start_clus + count) {
1028                 EXFAT_BITMAP_SET(exfat->alloc_bitmap,
1029                                 clus - EXFAT_FIRST_CLUSTER);
1030                 clus++;
1031         }
1032 }
1033
1034 static bool read_bitmap(struct exfat_de_iter *iter)
1035 {
1036         struct exfat_dentry *dentry;
1037         struct exfat *exfat;
1038
1039         exfat = iter->exfat;
1040         if (exfat_de_iter_get(iter, 0, &dentry))
1041                 return false;
1042
1043         exfat_debug("start cluster %#x, size %#" PRIx64 "\n",
1044                         le32_to_cpu(dentry->bitmap_start_clu),
1045                         le64_to_cpu(dentry->bitmap_size));
1046
1047         if (le64_to_cpu(dentry->bitmap_size) <
1048                         DIV_ROUND_UP(exfat->clus_count, 8)) {
1049                 exfat_err("invalid size of allocation bitmap. 0x%" PRIx64 "\n",
1050                                 le64_to_cpu(dentry->bitmap_size));
1051                 return false;
1052         }
1053         if (!heap_clus(exfat, le32_to_cpu(dentry->bitmap_start_clu))) {
1054                 exfat_err("invalid start cluster of allocate bitmap. 0x%x\n",
1055                                 le32_to_cpu(dentry->bitmap_start_clu));
1056                 return false;
1057         }
1058
1059         exfat->disk_bitmap_clus = le32_to_cpu(dentry->bitmap_start_clu);
1060         exfat->disk_bitmap_size = DIV_ROUND_UP(exfat->clus_count, 8);
1061
1062         exfat_bitmap_set_range(exfat, le64_to_cpu(dentry->bitmap_start_clu),
1063                         DIV_ROUND_UP(exfat->disk_bitmap_size,
1064                         exfat->clus_size));
1065
1066         if (exfat_read(exfat->blk_dev->dev_fd, exfat->disk_bitmap,
1067                         exfat->disk_bitmap_size,
1068                         exfat_c2o(exfat, exfat->disk_bitmap_clus)) !=
1069                         (ssize_t)exfat->disk_bitmap_size)
1070                 return false;
1071
1072         return true;
1073 }
1074
1075 static bool read_upcase_table(struct exfat_de_iter *iter)
1076 {
1077         struct exfat_dentry *dentry;
1078         struct exfat *exfat;
1079         ssize_t size;
1080         __le16 *upcase;
1081         __le32 checksum;
1082
1083         exfat = iter->exfat;
1084
1085         if (exfat_de_iter_get(iter, 0, &dentry))
1086                 return false;
1087
1088         if (!heap_clus(exfat, le32_to_cpu(dentry->upcase_start_clu))) {
1089                 exfat_err("invalid start cluster of upcase table. 0x%x\n",
1090                         le32_to_cpu(dentry->upcase_start_clu));
1091                 return false;
1092         }
1093
1094         size = (ssize_t)le64_to_cpu(dentry->upcase_size);
1095         if (size > (ssize_t)(EXFAT_MAX_UPCASE_CHARS * sizeof(__le16)) ||
1096                         size == 0 || size % sizeof(__le16)) {
1097                 exfat_err("invalid size of upcase table. 0x%" PRIx64 "\n",
1098                         le64_to_cpu(dentry->upcase_size));
1099                 return false;
1100         }
1101
1102         upcase = (__le16 *)malloc(size);
1103         if (!upcase) {
1104                 exfat_err("failed to allocate upcase table\n");
1105                 return false;
1106         }
1107
1108         if (exfat_read(exfat->blk_dev->dev_fd, upcase, size,
1109                         exfat_c2o(exfat,
1110                         le32_to_cpu(dentry->upcase_start_clu))) != size) {
1111                 exfat_err("failed to read upcase table\n");
1112                 free(upcase);
1113                 return false;
1114         }
1115
1116         checksum = 0;
1117         boot_calc_checksum((unsigned char *)upcase, size, false, &checksum);
1118         if (le32_to_cpu(dentry->upcase_checksum) != checksum) {
1119                 exfat_err("corrupted upcase table %#x (expected: %#x)\n",
1120                         checksum, le32_to_cpu(dentry->upcase_checksum));
1121                 free(upcase);
1122                 return false;
1123         }
1124
1125         exfat_bitmap_set_range(exfat, le32_to_cpu(dentry->upcase_start_clu),
1126                         DIV_ROUND_UP(le64_to_cpu(dentry->upcase_size),
1127                         exfat->clus_size));
1128
1129         free(upcase);
1130         return true;
1131 }
1132
1133 static int read_children(struct exfat *exfat, struct exfat_inode *dir)
1134 {
1135         int ret;
1136         struct exfat_inode *node = NULL;
1137         struct exfat_dentry *dentry;
1138         int dentry_count;
1139         struct exfat_de_iter *de_iter;
1140
1141         de_iter = &exfat->de_iter;
1142         ret = exfat_de_iter_init(de_iter, exfat, dir);
1143         if (ret == EOF)
1144                 return 0;
1145         else if (ret)
1146                 return ret;
1147
1148         while (1) {
1149                 ret = exfat_de_iter_get(de_iter, 0, &dentry);
1150                 if (ret == EOF) {
1151                         break;
1152                 } else if (ret) {
1153                         fsck_err(dir->parent, dir,
1154                                 "failed to get a dentry. %d\n", ret);
1155                         goto err;
1156                 }
1157
1158                 dentry_count = 1;
1159
1160                 switch (dentry->type) {
1161                 case EXFAT_FILE:
1162                         ret = read_file(de_iter, &node, &dentry_count);
1163                         if (ret < 0) {
1164                                 exfat_stat.error_count++;
1165                                 goto err;
1166                         } else if (ret) {
1167                                 exfat_stat.error_count++;
1168                                 exfat_stat.fixed_count++;
1169                         }
1170
1171                         if ((node->attr & ATTR_SUBDIR) && node->size) {
1172                                 node->parent = dir;
1173                                 list_add_tail(&node->sibling, &dir->children);
1174                                 list_add_tail(&node->list, &exfat->dir_list);
1175                         } else
1176                                 free_exfat_inode(node);
1177                         break;
1178                 case EXFAT_VOLUME:
1179                         if (!read_volume_label(de_iter)) {
1180                                 exfat_err("failed to verify volume label\n");
1181                                 ret = -EINVAL;
1182                                 goto err;
1183                         }
1184                         break;
1185                 case EXFAT_BITMAP:
1186                         if (!read_bitmap(de_iter)) {
1187                                 exfat_err(
1188                                         "failed to verify allocation bitmap\n");
1189                                 ret = -EINVAL;
1190                                 goto err;
1191                         }
1192                         break;
1193                 case EXFAT_UPCASE:
1194                         if (!read_upcase_table(de_iter)) {
1195                                 exfat_err(
1196                                         "failed to verify upcase table\n");
1197                                 ret = -EINVAL;
1198                                 goto err;
1199                         }
1200                         break;
1201                 case EXFAT_LAST:
1202                         goto out;
1203                 default:
1204                         if (IS_EXFAT_DELETED(dentry->type))
1205                                 break;
1206                         exfat_err("unknown entry type. 0x%x\n", dentry->type);
1207                         ret = -EINVAL;
1208                         goto err;
1209                 }
1210
1211                 exfat_de_iter_advance(de_iter, dentry_count);
1212         }
1213 out:
1214         exfat_de_iter_flush(de_iter);
1215         return 0;
1216 err:
1217         inode_free_children(dir, false);
1218         INIT_LIST_HEAD(&dir->children);
1219         exfat_de_iter_flush(de_iter);
1220         return ret;
1221 }
1222
1223 static int write_dirty_fat(struct exfat *exfat)
1224 {
1225         struct buffer_desc *bd;
1226         off_t offset;
1227         ssize_t len;
1228         size_t read_size, write_size;
1229         clus_t clus, last_clus, clus_count, i;
1230         unsigned int idx;
1231
1232         clus = 0;
1233         last_clus = le32_to_cpu(exfat->bs->bsx.clu_count) + 2;
1234         bd = exfat->buffer_desc;
1235         idx = 0;
1236         offset = le32_to_cpu(exfat->bs->bsx.fat_offset) *
1237                 exfat->sect_size;
1238         read_size = exfat->clus_size;
1239         write_size = exfat->sect_size;
1240
1241         while (clus < last_clus) {
1242                 clus_count = MIN(read_size / sizeof(clus_t), last_clus - clus);
1243                 len = exfat_read(exfat->blk_dev->dev_fd, bd[idx].buffer,
1244                                 clus_count * sizeof(clus_t), offset);
1245                 if (len != (ssize_t)(sizeof(clus_t) * clus_count)) {
1246                         exfat_err("failed to read fat entries, %zd\n", len);
1247                         return -EIO;
1248                 }
1249
1250                 /* TODO: read ahead */
1251
1252                 for (i = clus ? clus : EXFAT_FIRST_CLUSTER;
1253                                 i < clus + clus_count; i++) {
1254                         if (!EXFAT_BITMAP_GET(exfat->alloc_bitmap,
1255                                         i - EXFAT_FIRST_CLUSTER) &&
1256                                         ((clus_t *)bd[idx].buffer)[i - clus] !=
1257                                         EXFAT_FREE_CLUSTER) {
1258                                 ((clus_t *)bd[idx].buffer)[i - clus] =
1259                                         EXFAT_FREE_CLUSTER;
1260                                 bd[idx].dirty[(i - clus) /
1261                                         (write_size / sizeof(clus_t))] = true;
1262                         }
1263                 }
1264
1265                 for (i = 0; i < read_size; i += write_size) {
1266                         if (bd[idx].dirty[i / write_size]) {
1267                                 if (exfat_write(exfat->blk_dev->dev_fd,
1268                                                 &bd[idx].buffer[i], write_size,
1269                                                 offset + i) !=
1270                                                 (ssize_t)write_size) {
1271                                         exfat_err("failed to write "
1272                                                 "fat entries\n");
1273                                         return -EIO;
1274
1275                                 }
1276                                 bd[idx].dirty[i / write_size] = false;
1277                         }
1278                 }
1279
1280                 idx ^= 0x01;
1281                 clus = clus + clus_count;
1282                 offset += len;
1283         }
1284         return 0;
1285 }
1286
1287 static int write_dirty_bitmap(struct exfat *exfat)
1288 {
1289         struct buffer_desc *bd;
1290         off_t offset, last_offset, bitmap_offset;
1291         ssize_t len;
1292         ssize_t read_size, write_size, i, size;
1293         int idx;
1294
1295         offset = exfat_c2o(exfat, exfat->disk_bitmap_clus);
1296         last_offset = offset + exfat->disk_bitmap_size;
1297         bitmap_offset = 0;
1298         read_size = exfat->clus_size;
1299         write_size = exfat->sect_size;
1300
1301         bd = exfat->buffer_desc;
1302         idx = 0;
1303
1304         while (offset < last_offset) {
1305                 len = MIN(read_size, last_offset - offset);
1306                 if (exfat_read(exfat->blk_dev->dev_fd, bd[idx].buffer,
1307                                 len, offset) != (ssize_t)len)
1308                         return -EIO;
1309
1310                 /* TODO: read-ahead */
1311
1312                 for (i = 0; i < len; i += write_size) {
1313                         size = MIN(write_size, len - i);
1314                         if (memcmp(&bd[idx].buffer[i],
1315                                         exfat->alloc_bitmap + bitmap_offset + i,
1316                                         size)) {
1317                                 if (exfat_write(exfat->blk_dev->dev_fd,
1318                                         exfat->alloc_bitmap + bitmap_offset + i,
1319                                         size, offset + i) != size)
1320                                         return -EIO;
1321                         }
1322                 }
1323
1324                 idx ^= 0x01;
1325                 offset += len;
1326                 bitmap_offset += len;
1327         }
1328         return 0;
1329 }
1330
1331 static int reclaim_free_clusters(struct exfat *exfat)
1332 {
1333         if (write_dirty_fat(exfat)) {
1334                 exfat_err("failed to write fat entries\n");
1335                 return -EIO;
1336         }
1337         if (write_dirty_bitmap(exfat)) {
1338                 exfat_err("failed to write bitmap\n");
1339                 return -EIO;
1340         }
1341         return 0;
1342 }
1343
1344 /*
1345  * for each directory in @dir_list.
1346  * 1. read all dentries and allocate exfat_nodes for files and directories.
1347  *    and append directory exfat_nodes to the head of @dir_list
1348  * 2. free all of file exfat_nodes.
1349  * 3. if the directory does not have children, free its exfat_node.
1350  */
1351 static int exfat_filesystem_check(struct exfat *exfat)
1352 {
1353         struct exfat_inode *dir;
1354         int ret = 0, dir_errors;
1355
1356         if (!exfat->root) {
1357                 exfat_err("root is NULL\n");
1358                 return -ENOENT;
1359         }
1360
1361         list_add(&exfat->root->list, &exfat->dir_list);
1362
1363         while (!list_empty(&exfat->dir_list)) {
1364                 dir = list_entry(exfat->dir_list.next, struct exfat_inode, list);
1365
1366                 if (!(dir->attr & ATTR_SUBDIR)) {
1367                         fsck_err(dir->parent, dir,
1368                                 "failed to travel directories. "
1369                                 "the node is not directory\n");
1370                         ret = -EINVAL;
1371                         goto out;
1372                 }
1373
1374                 dir_errors = read_children(exfat, dir);
1375                 if (dir_errors) {
1376                         resolve_path(&path_resolve_ctx, dir);
1377                         exfat_debug("failed to check dentries: %s\n",
1378                                         path_resolve_ctx.local_path);
1379                         ret = dir_errors;
1380                 }
1381
1382                 list_del(&dir->list);
1383                 inode_free_file_children(dir);
1384                 inode_free_ancestors(dir);
1385         }
1386 out:
1387         exfat_free_dir_list(exfat);
1388         exfat->root = NULL;
1389         if (exfat->dirty_fat && reclaim_free_clusters(exfat))
1390                 return -EIO;
1391         return ret;
1392 }
1393
1394 static int exfat_root_dir_check(struct exfat *exfat)
1395 {
1396         struct exfat_inode *root;
1397         clus_t clus_count;
1398
1399         root = alloc_exfat_inode(ATTR_SUBDIR);
1400         if (!root) {
1401                 exfat_err("failed to allocate memory\n");
1402                 return -ENOMEM;
1403         }
1404
1405         root->first_clus = le32_to_cpu(exfat->bs->bsx.root_cluster);
1406         if (!root_get_clus_count(exfat, root, &clus_count)) {
1407                 exfat_err("failed to follow the cluster chain of root\n");
1408                 free_exfat_inode(root);
1409                 return -EINVAL;
1410         }
1411         root->size = clus_count * exfat->clus_size;
1412
1413         exfat->root = root;
1414         exfat_debug("root directory: start cluster[0x%x] size[0x%" PRIx64 "]\n",
1415                 root->first_clus, root->size);
1416         return 0;
1417 }
1418
1419 static char *bytes_to_human_readable(size_t bytes)
1420 {
1421         static const char * const units[] = {"B", "KB", "MB", "GB", "TB", "PB"};
1422         static char buf[15*4];
1423         unsigned int i, shift, quoti, remain;
1424
1425         shift = 0;
1426         for (i = 0; i < sizeof(units)/sizeof(units[0]); i++) {
1427                 if (bytes / (1ULL << (shift + 10)) == 0)
1428                         break;
1429                 shift += 10;
1430         }
1431
1432         quoti = (unsigned int)(bytes / (1ULL << shift));
1433         remain = 0;
1434         if (shift > 0) {
1435                 remain = (unsigned int)
1436                         ((bytes & ((1ULL << shift) - 1)) >> (shift - 10));
1437                 remain = (remain * 100) / 1024;
1438         }
1439
1440         snprintf(buf, sizeof(buf), "%u.%02u %s", quoti, remain, units[i]);
1441         return buf;
1442 }
1443
1444 static void exfat_show_info(struct exfat *exfat, const char *dev_name,
1445                         int errors)
1446 {
1447         exfat_info("sector size:  %s\n",
1448                 bytes_to_human_readable(1 << exfat->bs->bsx.sect_size_bits));
1449         exfat_info("cluster size: %s\n",
1450                 bytes_to_human_readable(exfat->clus_size));
1451         exfat_info("volume size:  %s\n",
1452                 bytes_to_human_readable(exfat->blk_dev->size));
1453
1454         printf("%s: %s. directories %ld, files %ld\n", dev_name,
1455                         errors ? "checking stopped" : "clean",
1456                         exfat_stat.dir_count, exfat_stat.file_count);
1457         if (errors || exfat->dirty)
1458                 printf("%s: files corrupted %ld, files fixed %ld\n", dev_name,
1459                         exfat_stat.error_count, exfat_stat.fixed_count);
1460 }
1461
1462 int main(int argc, char * const argv[])
1463 {
1464         struct fsck_user_input ui;
1465         struct exfat_blk_dev bd;
1466         struct exfat *exfat = NULL;
1467         struct pbr *bs = NULL;
1468         int c, ret, exit_code;
1469         bool version_only = false;
1470
1471         memset(&ui, 0, sizeof(ui));
1472         memset(&bd, 0, sizeof(bd));
1473
1474         print_level = EXFAT_ERROR;
1475
1476         if (!setlocale(LC_CTYPE, ""))
1477                 exfat_err("failed to init locale/codeset\n");
1478
1479         opterr = 0;
1480         while ((c = getopt_long(argc, argv, "arynpVvh", opts, NULL)) != EOF) {
1481                 switch (c) {
1482                 case 'n':
1483                         if (ui.options & FSCK_OPTS_REPAIR_ALL)
1484                                 usage(argv[0]);
1485                         ui.options |= FSCK_OPTS_REPAIR_NO;
1486                         break;
1487                 case 'r':
1488                         if (ui.options & FSCK_OPTS_REPAIR_ALL)
1489                                 usage(argv[0]);
1490                         ui.options |= FSCK_OPTS_REPAIR_ASK;
1491                         break;
1492                 case 'y':
1493                         if (ui.options & FSCK_OPTS_REPAIR_ALL)
1494                                 usage(argv[0]);
1495                         ui.options |= FSCK_OPTS_REPAIR_YES;
1496                         break;
1497                 case 'a':
1498                 case 'p':
1499                         if (ui.options & FSCK_OPTS_REPAIR_ALL)
1500                                 usage(argv[0]);
1501                         ui.options |= FSCK_OPTS_REPAIR_AUTO;
1502                         break;
1503                 case 'V':
1504                         version_only = true;
1505                         break;
1506                 case 'v':
1507                         if (print_level < EXFAT_DEBUG)
1508                                 print_level++;
1509                         break;
1510                 case '?':
1511                 case 'h':
1512                 default:
1513                         usage(argv[0]);
1514                 }
1515         }
1516
1517         show_version();
1518         if (optind != argc - 1)
1519                 usage(argv[0]);
1520
1521         if (version_only)
1522                 exit(FSCK_EXIT_SYNTAX_ERROR);
1523         if (ui.options & FSCK_OPTS_REPAIR_WRITE)
1524                 ui.ei.writeable = true;
1525         else {
1526                 ui.options |= FSCK_OPTS_REPAIR_NO;
1527                 ui.ei.writeable = false;
1528         }
1529
1530         snprintf(ui.ei.dev_name, sizeof(ui.ei.dev_name), "%s", argv[optind]);
1531         ret = exfat_get_blk_dev_info(&ui.ei, &bd);
1532         if (ret < 0) {
1533                 exfat_err("failed to open %s. %d\n", ui.ei.dev_name, ret);
1534                 return FSCK_EXIT_OPERATION_ERROR;
1535         }
1536
1537         exfat = (struct exfat *)calloc(1, sizeof(*exfat));
1538         if (!exfat) {
1539                 exfat_err("failed to allocate exfat\n");
1540                 ret = -ENOMEM;
1541                 goto err;
1542         }
1543         exfat->blk_dev = &bd;
1544         exfat->options = ui.options;
1545
1546         ret = exfat_boot_region_check(exfat, &bs);
1547         if (ret)
1548                 goto err;
1549
1550         ret = init_exfat(exfat, bs);
1551         if (ret)
1552                 goto err;
1553
1554         if (exfat_mark_volume_dirty(exfat, true)) {
1555                 ret = -EIO;
1556                 goto err;
1557         }
1558
1559         exfat_debug("verifying root directory...\n");
1560         ret = exfat_root_dir_check(exfat);
1561         if (ret) {
1562                 exfat_err("failed to verify root directory.\n");
1563                 goto out;
1564         }
1565
1566         exfat_debug("verifying directory entries...\n");
1567         ret = exfat_filesystem_check(exfat);
1568         if (ret)
1569                 goto out;
1570
1571         if (ui.ei.writeable && fsync(bd.dev_fd)) {
1572                 exfat_err("failed to sync\n");
1573                 ret = -EIO;
1574                 goto out;
1575         }
1576         exfat_mark_volume_dirty(exfat, false);
1577
1578 out:
1579         exfat_show_info(exfat, ui.ei.dev_name, ret);
1580 err:
1581         if (ret == -EINVAL)
1582                 exit_code = FSCK_EXIT_ERRORS_LEFT;
1583         else if (ret)
1584                 exit_code = FSCK_EXIT_OPERATION_ERROR;
1585         else if (exfat->dirty)
1586                 exit_code = FSCK_EXIT_CORRECTED;
1587         else
1588                 exit_code = FSCK_EXIT_NO_ERRORS;
1589
1590         free_exfat(exfat);
1591         close(bd.dev_fd);
1592         return exit_code;
1593 }