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 void usage()
  34 {
  35         fprintf(stderr, "usage: t_dir_offset2: <dir> [bufsize]\n");
  36         exit(EXIT_FAILURE);
  37 }
  38
  39 int main(int argc, char *argv[])
  40 {
  41         int fd;
  42         char buf[BUF_SIZE];
  43         int nread, bufsize = BUF_SIZE;
  44         struct linux_dirent64 *d;
  45         int bpos, total, i;
  46         off_t lret;
  47         int retval = EXIT_SUCCESS;
  48
  49         if (argc > 2) {
  50                 bufsize = atoi(argv[2]);
  51                 if (!bufsize)
  52                         usage();
  53                 if (bufsize > BUF_SIZE)
  54                         bufsize = BUF_SIZE;
  55         } else if (argc < 2) {
  56                 usage();
  57         }
  58
  59         fd = open(argv[1], O_RDONLY | O_DIRECTORY);
  60         if (fd < 0) {
  61                 perror("open");
  62                 exit(EXIT_FAILURE);
  63         }
  64
  65         total = 0;
  66         for ( ; ; ) {
  67                 nread = syscall(SYS_getdents64, fd, buf, bufsize);
  68                 if (nread == -1) {
  69                         perror("getdents");
  70                         exit(EXIT_FAILURE);
  71                 }
  72
  73                 if (nread == 0)
  74                         break;
  75
  76                 for (bpos = 0; bpos < nread; total++) {
  77                         d = (struct linux_dirent64 *) (buf + bpos);
  78
  79                         if (total >= HISTORY_LEN) {
  80                                 fprintf(stderr, "too many files\n");
  81                                 break;
  82                         }
  83
  84                         for (i = 0; i < total; i++)
  85                         {
  86                                 if (d_off_history[i] == d->d_off) {
  87                                         fprintf(stderr, "entries %d and %d have duplicate d_off %lld\n",
  88                                                 i, total, (long long int)d->d_off);
  89                                         retval = EXIT_FAILURE;
  90                                 }
  91                         }
  92                         d_off_history[total] = d->d_off;
  93                         d_ino_history[total] = d->d_ino;
  94                         bpos += d->d_reclen;
  95                 }
  96         }
  97
  98         /* check if seek works correctly */
  99         d = (struct linux_dirent64 *)buf;
 100         for (i = total - 1; i >= 0; i--)
 101         {
 102                 lret = lseek(fd, i > 0 ? d_off_history[i - 1] : 0, SEEK_SET);
 103                 if (lret == -1) {
 104                         perror("lseek");
 105                         exit(EXIT_FAILURE);
 106                 }
 107
 108                 nread = syscall(SYS_getdents64, fd, buf, bufsize);
 109                 if (nread == -1) {
 110                         perror("getdents");
 111                         exit(EXIT_FAILURE);
 112                 }
 113
 114                 if (nread == 0) {
 115                         fprintf(stderr, "getdents returned 0 on entry %d\n", i);
 116                         retval = EXIT_FAILURE;
 117                 }
 118
 119                 if (d->d_ino != d_ino_history[i]) {
 120                         fprintf(stderr, "entry %d has inode %lld, expected %lld\n",
 121                                 i, (long long int)d->d_ino, (long long int)d_ino_history[i]);
 122                         retval = EXIT_FAILURE;
 123                 }
 124         }
 125
 126         close(fd);
 127         exit(retval);
 128 }