sysdeps/mach/hurd/readdir64.c

   1 /* Copyright (C) 2001-2016 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 #include <dirent.h>
  19 #include <stddef.h>
  20 #include <hurd.h>
  21 #include <hurd/fs.h>
  22 #include <hurd/fd.h>
  23 #include "dirstream.h"
  24
  25 /* Read a directory entry from DIRP.  */
  26 struct dirent64 *
  27 __readdir64 (DIR *dirp)
  28 {
  29   struct dirent64 *dp;
  30
  31   if (dirp == NULL)
  32     {
  33       errno = EINVAL;
  34       return NULL;
  35     }
  36
  37   __libc_lock_lock (dirp->__lock);
  38
  39   do
  40     {
  41       if (dirp->__ptr - dirp->__data >= dirp->__size)
  42         {
  43           /* We've emptied out our buffer.  Refill it.  */
  44
  45           char *data = dirp->__data;
  46           int nentries;
  47           error_t err;
  48
  49           if (err = HURD_FD_PORT_USE (dirp->__fd,
  50                                       __dir_readdir (port,
  51                                                      &data, &dirp->__size,
  52                                                      dirp->__entry_ptr,
  53                                                      -1, 0, &nentries)))
  54             {
  55               __hurd_fail (err);
  56               dp = NULL;
  57               break;
  58             }
  59
  60           /* DATA now corresponds to entry index DIRP->__entry_ptr.  */
  61           dirp->__entry_data = dirp->__entry_ptr;
  62
  63           if (data != dirp->__data)
  64             {
  65               /* The data was passed out of line, so our old buffer is no
  66                  longer useful.  Deallocate the old buffer and reset our
  67                  information for the new buffer.  */
  68               __vm_deallocate (__mach_task_self (),
  69                                (vm_address_t) dirp->__data,
  70                                dirp->__allocation);
  71               dirp->__data = data;
  72               dirp->__allocation = round_page (dirp->__size);
  73             }
  74
  75           /* Reset the pointer into the buffer.  */
  76           dirp->__ptr = dirp->__data;
  77
  78           if (nentries == 0)
  79             {
  80               /* End of file.  */
  81               dp = NULL;
  82               break;
  83             }
  84
  85           /* We trust the filesystem to return correct data and so we
  86              ignore NENTRIES.  */
  87         }
  88
  89       dp = (struct dirent64 *) dirp->__ptr;
  90       dirp->__ptr += dp->d_reclen;
  91       ++dirp->__entry_ptr;
  92
  93       /* Loop to ignore deleted files.  */
  94     } while (dp->d_fileno == 0);
  95
  96   __libc_lock_unlock (dirp->__lock);
  97
  98   return dp;
  99 }
 100
 101 weak_alias (__readdir64, readdir64)