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