src/t_dir_offset2.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2011 Gražvydas Ignotas
   4  */
   5
   6 /*
   7  * This test checks if no duplicate d_off values are returned and
   8  * that these offsets are seekable to entry with the right inode.
   9  */
  10
  11 #include <fcntl.h>
  12 #include <stdio.h>
  13 #include <unistd.h>
  14 #include <stdint.h>
  15 #include <stdlib.h>
  16 #include <sys/stat.h>
  17 #include <sys/syscall.h>
  18
  19 struct linux_dirent64 {
  20         uint64_t        d_ino;
  21         uint64_t        d_off;
  22         unsigned short  d_reclen;
  23         unsigned char   d_type;
  24         char            d_name[0];
  25 };
  26
  27 #define BUF_SIZE 4096
  28 #define HISTORY_LEN 1024
  29
  30 static uint64_t d_off_history[HISTORY_LEN];
  31 static uint64_t d_ino_history[HISTORY_LEN];
  32
  33 int
  34 main(int argc, char *argv[])
  35 {
  36         int fd, nread;
  37         char buf[BUF_SIZE];
  38         struct linux_dirent64 *d;
  39         int bpos, total, i;
  40         off_t lret;
  41         int retval = EXIT_SUCCESS;
  42
  43         fd = open(argv[1], O_RDONLY | O_DIRECTORY);
  44         if (fd < 0) {
  45                 perror("open");
  46                 exit(EXIT_FAILURE);
  47         }
  48
  49         total = 0;
  50         for ( ; ; ) {
  51                 nread = syscall(SYS_getdents64, fd, buf, BUF_SIZE);
  52                 if (nread == -1) {
  53                         perror("getdents");
  54                         exit(EXIT_FAILURE);
  55                 }
  56
  57                 if (nread == 0)
  58                         break;
  59
  60                 for (bpos = 0; bpos < nread; total++) {
  61                         d = (struct linux_dirent64 *) (buf + bpos);
  62
  63                         if (total >= HISTORY_LEN) {
  64                                 fprintf(stderr, "too many files\n");
  65                                 break;
  66                         }
  67
  68                         for (i = 0; i < total; i++)
  69                         {
  70                                 if (d_off_history[i] == d->d_off) {
  71                                         fprintf(stderr, "entries %d and %d have duplicate d_off %lld\n",
  72                                                 i, total, (long long int)d->d_off);
  73                                         retval = EXIT_FAILURE;
  74                                 }
  75                         }
  76                         d_off_history[total] = d->d_off;
  77                         d_ino_history[total] = d->d_ino;
  78                         bpos += d->d_reclen;
  79                 }
  80         }
  81
  82         /* check if seek works correctly */
  83         d = (struct linux_dirent64 *)buf;
  84         for (i = total - 1; i >= 0; i--)
  85         {
  86                 lret = lseek(fd, i > 0 ? d_off_history[i - 1] : 0, SEEK_SET);
  87                 if (lret == -1) {
  88                         perror("lseek");
  89                         exit(EXIT_FAILURE);
  90                 }
  91
  92                 nread = syscall(SYS_getdents64, fd, buf, BUF_SIZE);
  93                 if (nread == -1) {
  94                         perror("getdents");
  95                         exit(EXIT_FAILURE);
  96                 }
  97
  98                 if (nread == 0) {
  99                         fprintf(stderr, "getdents returned 0 on entry %d\n", i);
 100                         retval = EXIT_FAILURE;
 101                 }
 102
 103                 if (d->d_ino != d_ino_history[i]) {
 104                         fprintf(stderr, "entry %d has inode %lld, expected %lld\n",
 105                                 i, (long long int)d->d_ino, (long long int)d_ino_history[i]);
 106                         retval = EXIT_FAILURE;
 107                 }
 108         }
 109
 110         close(fd);
 111         exit(retval);
 112 }