fsal_truncate.c

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/*
 * vim:expandtab:shiftwidth=8:tabstop=8:
 *
 * Copyright CEA/DAM/DIF  (2008)
 * contributeur : Philippe DENIEL   philippe.deniel@cea.fr
 *                Thomas LEIBOVICI  thomas.leibovici@cea.fr
 *
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 3 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * ------------- 
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "fsal.h"
#include "fsal_internal.h"
#include "fsal_convert.h"

#include <unistd.h>
#include <sys/types.h>

fsal_status_t XFSFSAL_truncate(fsal_handle_t * p_filehandle, /* IN */
                               fsal_op_context_t * p_context,        /* IN */
                               fsal_size_t length,      /* IN */
                               fsal_file_t * file_descriptor,        /* Unused in this FSAL */
                               fsal_attrib_list_t * p_object_attributes /* [ IN/OUT ] */
    )
{

  int rc, errsv;
  int fd;
  fsal_status_t st;

  /* sanity checks.
   * note : object_attributes is optional.
   */
  if(!p_filehandle || !p_context)
    Return(ERR_FSAL_FAULT, 0, INDEX_FSAL_truncate);

  /* get the path of the file and its handle */
  TakeTokenFSCall();
  st = fsal_internal_handle2fd(p_context, p_filehandle, &fd, O_RDWR);
  ReleaseTokenFSCall();

  if(FSAL_IS_ERROR(st))
    ReturnStatus(st, INDEX_FSAL_truncate);

  /* Executes the POSIX truncate operation */

  TakeTokenFSCall();
  rc = ftruncate(fd, length);
  errsv = errno;
  ReleaseTokenFSCall();

  close(fd);

  /* convert return code */
  if(rc)
    {
      if(errsv == ENOENT)
        Return(ERR_FSAL_STALE, errsv, INDEX_FSAL_truncate);
      else
        Return(posix2fsal_error(errsv), errsv, INDEX_FSAL_truncate);
    }

  /* Optionally retrieve attributes */
  if(p_object_attributes)
    {

      fsal_status_t st;

      st = XFSFSAL_getattrs(p_filehandle, p_context, p_object_attributes);

      if(FSAL_IS_ERROR(st))
        {
          FSAL_CLEAR_MASK(p_object_attributes->asked_attributes);
          FSAL_SET_MASK(p_object_attributes->asked_attributes, FSAL_ATTR_RDATTR_ERR);
        }

    }

  /* No error occurred */
  Return(ERR_FSAL_NO_ERROR, 0, INDEX_FSAL_truncate);

}