fsck/repair.c

   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   2 /*
   3  *  Copyright (C) 2020 Hyunchul Lee <hyc.lee@gmail.com>
   4  */
   5 #include <stdio.h>
   6 #include <string.h>
   7
   8 #include "exfat_ondisk.h"
   9 #include "libexfat.h"
  10 #include "fsck.h"
  11 #include "repair.h"
  12
  13 struct exfat_repair_problem {
  14         er_problem_code_t       prcode;
  15         const char              *description;
  16         bool (*fix_problem)(struct exfat *exfat,
  17                         union exfat_repair_context *rctx);
  18 };
  19
  20 static bool fix_bs_checksum(struct exfat *exfat,
  21                         union exfat_repair_context *rctx)
  22 {
  23         unsigned int size;
  24         unsigned int i;
  25
  26         size = EXFAT_SECTOR_SIZE(exfat->bs);
  27         for (i = 0; i < size/sizeof(__le32); i++) {
  28                 ((__le32 *)rctx->bs_checksum.checksum_sect)[i] =
  29                                 rctx->bs_checksum.checksum;
  30         }
  31
  32         if (exfat_write(exfat->blk_dev->dev_fd,
  33                         rctx->bs_checksum.checksum_sect,
  34                         size, size * 11) != size) {
  35                 exfat_err("failed to write checksum sector\n");
  36                 return false;
  37         }
  38
  39         return true;
  40 }
  41
  42 static struct exfat_repair_problem problems[] = {
  43         {ER_BS_CHECKSUM,
  44                 "the checksum of boot sector is not correct",
  45                 fix_bs_checksum},
  46 };
  47
  48 static struct exfat_repair_problem *find_problem(er_problem_code_t prcode)
  49 {
  50         unsigned int i;
  51
  52         for (i = 0; i < sizeof(problems)/sizeof(problems[0]); i++) {
  53                 if (problems[i].prcode == prcode) {
  54                         return &problems[i];
  55                 }
  56         }
  57         return NULL;
  58 }
  59
  60 static bool ask_repair(struct exfat *exfat, struct exfat_repair_problem *pr)
  61 {
  62         char answer[8];
  63
  64         switch (exfat->options & FSCK_OPTS_REPAIR) {
  65         case FSCK_OPTS_REPAIR_ASK:
  66                 do {
  67                         printf("%s: Fix (y/N)?", pr->description);
  68                         fflush(stdout);
  69
  70                         if (fgets(answer, sizeof(answer), stdin)) {
  71                                 if (strcasecmp(answer, "Y\n") == 0)
  72                                         return true;
  73                                 else if (strcasecmp(answer, "\n") == 0 ||
  74                                         strcasecmp(answer, "N\n") == 0)
  75                                         return false;
  76                         }
  77                 } while (1);
  78                 return false;
  79         case FSCK_OPTS_REPAIR_YES:
  80                 return true;
  81         case FSCK_OPTS_REPAIR_NO:
  82         case 0:
  83         default:
  84                 return false;
  85         }
  86         return false;
  87 }
  88
  89 bool exfat_repair(struct exfat *exfat, er_problem_code_t prcode,
  90                         union exfat_repair_context *rctx)
  91 {
  92         struct exfat_repair_problem *pr = NULL;
  93         int need_repair;
  94
  95         need_repair = ask_repair(exfat, pr);
  96         if (!need_repair)
  97                 return false;
  98
  99         pr = find_problem(prcode);
 100         if (!pr) {
 101                 exfat_err("unknown problem code. %#x\n", prcode);
 102                 return false;
 103         }
 104
 105         return pr->fix_problem(exfat, rctx);
 106 }