fsal_unlink.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>

extern fsal_status_t gpfsfsal_xstat_2_fsal_attributes(gpfsfsal_xstat_t *p_buffxstat,
                                                      fsal_attrib_list_t *p_fsalattr_out);

fsal_status_t GPFSFSAL_unlink(fsal_handle_t * p_parent_directory_handle,    /* IN */
                          fsal_name_t * p_object_name,  /* IN */
                          fsal_op_context_t * p_context,        /* IN */
                          fsal_attrib_list_t * p_parent_directory_attributes    /* [IN/OUT ] */
    )
{

  fsal_status_t status;
  gpfsfsal_xstat_t buffxstat;
  fsal_accessflags_t access_mask = 0;
  fsal_attrib_list_t parent_dir_attrs;

  /* sanity checks. */
  if(!p_parent_directory_handle || !p_context || !p_object_name)
    Return(ERR_FSAL_FAULT, 0, INDEX_FSAL_unlink);

  /* get directory metadata */
  parent_dir_attrs.asked_attributes = GPFS_SUPPORTED_ATTRIBUTES;
  status = GPFSFSAL_getattrs(p_parent_directory_handle, p_context, &parent_dir_attrs);
  if(FSAL_IS_ERROR(status))
    ReturnStatus(status, INDEX_FSAL_unlink);

  /* build the child path */

  /* get file metadata */
  TakeTokenFSCall();
  status = fsal_internal_stat_name(p_context, p_parent_directory_handle,
                                   p_object_name, &buffxstat.buffstat);
  ReleaseTokenFSCall();
  if(FSAL_IS_ERROR(status))
    ReturnStatus(status, INDEX_FSAL_unlink);

  /* check access rights */

  /* Sticky bit on the directory => the user who wants to delete the file must own it or its parent dir */
  if((fsal2unix_mode(parent_dir_attrs.mode) & S_ISVTX)
     && parent_dir_attrs.owner != p_context->credential.user
     && buffxstat.buffstat.st_uid != p_context->credential.user
     && p_context->credential.user != 0)
    {
      Return(ERR_FSAL_ACCESS, 0, INDEX_FSAL_unlink);
    }

  /* client must be able to lookup the parent directory and modify it */

  /* Set both mode and ace4 mask */
  access_mask = FSAL_MODE_MASK_SET(FSAL_W_OK  | FSAL_X_OK) |
                FSAL_ACE4_MASK_SET(FSAL_ACE_PERM_DELETE_CHILD);

  if(!p_context->export_context->fe_static_fs_info->accesscheck_support)
  status = fsal_internal_testAccess(p_context, access_mask, NULL, &parent_dir_attrs);
  else
    status = fsal_internal_access(p_context, p_parent_directory_handle, access_mask,
                                  &parent_dir_attrs);
  if(FSAL_IS_ERROR(status))
    ReturnStatus(status, INDEX_FSAL_unlink);

  /******************************
   * DELETE FROM THE FILESYSTEM *
   ******************************/
  TakeTokenFSCall();
  status = fsal_internal_unlink(p_context, p_parent_directory_handle,
                                p_object_name, &buffxstat.buffstat);
  ReleaseTokenFSCall();

  if(FSAL_IS_ERROR(status))
    ReturnStatus(status, INDEX_FSAL_unlink);

  /***********************
   * FILL THE ATTRIBUTES *
   ***********************/

  if(p_parent_directory_attributes)
    {
      buffxstat.attr_valid = XATTR_STAT;
      status = gpfsfsal_xstat_2_fsal_attributes(&buffxstat,
                                                p_parent_directory_attributes);
      if(FSAL_IS_ERROR(status))
        {
          FSAL_CLEAR_MASK(p_parent_directory_attributes->asked_attributes);
          FSAL_SET_MASK(p_parent_directory_attributes->asked_attributes,
                        FSAL_ATTR_RDATTR_ERR);
        }
    }
  /* OK */
  Return(ERR_FSAL_NO_ERROR, 0, INDEX_FSAL_unlink);

}