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 <errno.h>
  12 #include <fcntl.h>
  13 #include <stdio.h>
  14 #include <unistd.h>
  15 #include <stdint.h>
  16 #include <stdlib.h>
  17 #include <string.h>
  18 #include <sys/stat.h>
  19 #include <sys/syscall.h>
  20
  21 struct linux_dirent64 {
  22         uint64_t        d_ino;
  23         uint64_t        d_off;
  24         unsigned short  d_reclen;
  25         unsigned char   d_type;
  26         char            d_name[0];
  27 };
  28
  29 #define BUF_SIZE 4096
  30 #define HISTORY_LEN 1024
  31
  32 static uint64_t d_off_history[HISTORY_LEN];
  33 static uint64_t d_ino_history[HISTORY_LEN];
  34
  35 void usage()
  36 {
  37         fprintf(stderr, "usage: t_dir_offset2: <dir> [[bufsize] <filename> [-v]]\n");
  38         exit(EXIT_FAILURE);
  39 }
  40
  41 int main(int argc, char *argv[])
  42 {
  43         int fd;
  44         char buf[BUF_SIZE];
  45         int nread, bufsize = BUF_SIZE;
  46         struct linux_dirent64 *d;
  47         int bpos, total, i;
  48         off_t lret;
  49         int retval = EXIT_SUCCESS;
  50         const char *filename = NULL;
  51         int exists = 0, found = 0;
  52         int verbose = 0;
  53
  54         if (argc > 2) {
  55                 bufsize = atoi(argv[2]);
  56                 if (!bufsize)
  57                         usage();
  58                 if (bufsize > BUF_SIZE)
  59                         bufsize = BUF_SIZE;
  60
  61                 if (argc > 3) {
  62                         filename = argv[3];
  63                         if (argc > 4 && !strcmp(argv[4], "-v"))
  64                                 verbose = 1;
  65                 }
  66         } else if (argc < 2) {
  67                 usage();
  68         }
  69
  70         fd = open(argv[1], O_RDONLY | O_DIRECTORY);
  71         if (fd < 0) {
  72                 perror("open");
  73                 exit(EXIT_FAILURE);
  74         }
  75
  76         if (filename) {
  77                 exists = !faccessat(fd, filename, F_OK, AT_SYMLINK_NOFOLLOW);
  78                 if (!exists && errno != ENOENT) {
  79                         perror("faccessat");
  80                         exit(EXIT_FAILURE);
  81                 }
  82         }
  83
  84         total = 0;
  85         for ( ; ; ) {
  86                 nread = syscall(SYS_getdents64, fd, buf, bufsize);
  87                 if (nread == -1) {
  88                         perror("getdents");
  89                         exit(EXIT_FAILURE);
  90                 }
  91
  92                 if (nread == 0)
  93                         break;
  94
  95                 for (bpos = 0; bpos < nread; total++) {
  96                         d = (struct linux_dirent64 *) (buf + bpos);
  97
  98                         if (total >= HISTORY_LEN) {
  99                                 fprintf(stderr, "too many files\n");
 100                                 break;
 101                         }
 102
 103                         for (i = 0; i < total; i++)
 104                         {
 105                                 if (d_off_history[i] == d->d_off) {
 106                                         fprintf(stderr, "entries %d and %d have duplicate d_off %lld\n",
 107                                                 i, total, (long long int)d->d_off);
 108                                         retval = EXIT_FAILURE;
 109                                 }
 110                         }
 111                         d_off_history[total] = d->d_off;
 112                         d_ino_history[total] = d->d_ino;
 113                         if (filename) {
 114                                 if (verbose)
 115                                         printf("entry #%d: %s (d_ino=%lld, d_off=%lld)\n",
 116                                                i, d->d_name, (long long int)d->d_ino,
 117                                                (long long int)d->d_off);
 118                                 if (!strcmp(filename, d->d_name))
 119                                         found = 1;
 120                         }
 121                         bpos += d->d_reclen;
 122                 }
 123         }
 124
 125         if (filename) {
 126                 if (exists == found) {
 127                         printf("entry %s %sfound as expected\n", filename, found ? "" : "not ");
 128                 } else {
 129                         fprintf(stderr, "%s entry %s\n",
 130                                 exists ? "missing" : "stale", filename);
 131                         exit(EXIT_FAILURE);
 132                 }
 133         }
 134
 135         /* check if seek works correctly */
 136         d = (struct linux_dirent64 *)buf;
 137         for (i = total - 1; i >= 0; i--)
 138         {
 139                 lret = lseek(fd, i > 0 ? d_off_history[i - 1] : 0, SEEK_SET);
 140                 if (lret == -1) {
 141                         perror("lseek");
 142                         exit(EXIT_FAILURE);
 143                 }
 144
 145                 nread = syscall(SYS_getdents64, fd, buf, bufsize);
 146                 if (nread == -1) {
 147                         perror("getdents");
 148                         exit(EXIT_FAILURE);
 149                 }
 150
 151                 if (nread == 0) {
 152                         fprintf(stderr, "getdents returned 0 on entry %d\n", i);
 153                         retval = EXIT_FAILURE;
 154                 }
 155
 156                 if (d->d_ino != d_ino_history[i]) {
 157                         fprintf(stderr, "entry %d has inode %lld, expected %lld\n",
 158                                 i, (long long int)d->d_ino, (long long int)d_ino_history[i]);
 159                         retval = EXIT_FAILURE;
 160                 }
 161         }
 162
 163         close(fd);
 164         exit(retval);
 165 }