sysdeps/mach/hurd/readdir64_r.c

   1 /* Copyright (C) 2001,02 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, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #include <dirent.h>
  20 #include <stddef.h>
  21 #include <string.h>
  22 #include <hurd.h>
  23 #include <hurd/fs.h>
  24 #include <hurd/fd.h>
  25 #include "dirstream.h"
  26
  27 /* Read a directory entry from DIRP.  */
  28 int
  29 __readdir64_r (DIR *dirp, struct dirent64 *entry, struct dirent64 **result)
  30 {
  31   struct dirent64 *dp;
  32   error_t err = 0;
  33
  34   if (dirp == NULL)
  35     {
  36       errno = EINVAL;
  37       return errno;
  38     }
  39
  40   __libc_lock_lock (dirp->__lock);
  41
  42   do
  43     {
  44       if (dirp->__ptr - dirp->__data >= dirp->__size)
  45         {
  46           /* We've emptied out our buffer.  Refill it.  */
  47
  48           char *data = dirp->__data;
  49           int nentries;
  50
  51           if (err = HURD_FD_PORT_USE (dirp->__fd,
  52                                       __dir_readdir (port,
  53                                                      &data, &dirp->__size,
  54                                                      dirp->__entry_ptr,
  55                                                      -1, 0, &nentries)))
  56             {
  57               __hurd_fail (err);
  58               dp = NULL;
  59               break;
  60             }
  61
  62           /* DATA now corresponds to entry index DIRP->__entry_ptr.  */
  63           dirp->__entry_data = dirp->__entry_ptr;
  64
  65           if (data != dirp->__data)
  66             {
  67               /* The data was passed out of line, so our old buffer is no
  68                  longer useful.  Deallocate the old buffer and reset our
  69                  information for the new buffer.  */
  70               __vm_deallocate (__mach_task_self (),
  71                                (vm_address_t) dirp->__data,
  72                                dirp->__allocation);
  73               dirp->__data = data;
  74               dirp->__allocation = round_page (dirp->__size);
  75             }
  76
  77           /* Reset the pointer into the buffer.  */
  78           dirp->__ptr = dirp->__data;
  79
  80           if (nentries == 0)
  81             {
  82               /* End of file.  */
  83               dp = NULL;
  84               break;
  85             }
  86
  87           /* We trust the filesystem to return correct data and so we
  88              ignore NENTRIES.  */
  89         }
  90
  91       dp = (struct dirent64 *) dirp->__ptr;
  92       dirp->__ptr += dp->d_reclen;
  93       ++dirp->__entry_ptr;
  94
  95       /* Loop to ignore deleted files.  */
  96     } while (dp->d_fileno == 0);
  97
  98   if (dp)
  99     {
 100       *entry = *dp;
 101       memcpy (entry->d_name, dp->d_name, dp->d_namlen + 1);
 102       *result = entry;
 103     }
 104   else
 105     *result = NULL;
 106
 107   __libc_lock_unlock (dirp->__lock);
 108
 109   return dp ? 0 : err ? errno : 0;
 110 }
 111
 112 weak_alias (__readdir64_r, readdir64_r)