1  /* Check if internal buffer reallocation work for large paths (BZ #28126)
       2     Copyright (C) 2021-2023 Free Software Foundation, Inc.
       3     This file is part of the GNU C Library.
       4  
       5     The GNU C Library is free software; you can redistribute it and/or
       6     modify it under the terms of the GNU Lesser General Public
       7     License as published by the Free Software Foundation; either
       8     version 2.1 of the License, or (at your option) any later version.
       9  
      10     The GNU C Library is distributed in the hope that it will be useful,
      11     but WITHOUT ANY WARRANTY; without even the implied warranty of
      12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      13     Lesser General Public License for more details.
      14  
      15     You should have received a copy of the GNU Lesser General Public
      16     License along with the GNU C Library; if not, see
      17     <https://www.gnu.org/licenses/>.  */
      18  
      19  #include <errno.h>
      20  #include <ftw.h>
      21  #include <limits.h>
      22  #include <string.h>
      23  #include <stdlib.h>
      24  #include <support/check.h>
      25  #include <support/support.h>
      26  #include <support/temp_file.h>
      27  #include <support/xunistd.h>
      28  #include <stdio.h>
      29  
      30  static int
      31  my_func (const char *file, const struct stat *sb, int flag)
      32  {
      33    return 0;
      34  }
      35  
      36  static const char folder[NAME_MAX] = { [0 ... 253] = 'a', [254] = '\0' };
      37  
      38  #define NSUBFOLDERS 16
      39  static int nsubfolders;
      40  
      41  static void
      42  do_cleanup (void)
      43  {
      44    xchdir ("..");
      45    for (int i = 0; i < nsubfolders; i++)
      46      {
      47        remove (folder);
      48        xchdir ("..");
      49      }
      50    remove (folder);
      51  }
      52  #define CLEANUP_HANDLER do_cleanup
      53  
      54  static void
      55  check_mkdir (const char *path)
      56  {
      57    int r = mkdir (path, 0777);
      58    /* Some filesystem such as overlayfs does not support larger path required
      59       to trigger the internal buffer reallocation.  */
      60    if (r != 0)
      61      {
      62        if (errno == ENAMETOOLONG)
      63  	FAIL_UNSUPPORTED ("the filesystem does not support the required"
      64  			  "large path");
      65        else
      66  	FAIL_EXIT1 ("mkdir (\"%s\", 0%o): %m", folder, 0777);
      67      }
      68  }
      69  
      70  static int
      71  do_test (void)
      72  {
      73    char *tempdir = support_create_temp_directory ("tst-bz28126");
      74  
      75    /* Create path with various subfolders to force an internal buffer
      76       reallocation within ntfw.  */
      77    char *path = xasprintf ("%s/%s", tempdir, folder);
      78    check_mkdir (path);
      79    xchdir (path);
      80    free (path);
      81    for (int i = 0; i < NSUBFOLDERS - 1; i++)
      82      {
      83        check_mkdir (folder);
      84        xchdir (folder);
      85        nsubfolders++;
      86      }
      87  
      88    TEST_COMPARE (ftw (tempdir, my_func, 20), 0);
      89  
      90    free (tempdir);
      91  
      92    do_cleanup ();
      93  
      94    return 0;
      95  }
      96  
      97  #include <support/test-driver.c>