text: /****************************************************************************
   * include/nuttx/fs/unionfs.h
   *
   *   Copyright (C) 2015 Gregory Nutt. All rights reserved.
   *   Author: Gregory Nutt <gnutt@nuttx.org>
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   *
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in
   *    the documentation and/or other materials provided with the
   *    distribution.
   * 3. Neither the name NuttX nor the names of its contributors may be
   *    used to endorse or promote products derived from this software
   *    without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
   * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
   * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
   * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
   * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
   * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
   * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
   * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   * POSSIBILITY OF SUCH DAMAGE.
   *
   ****************************************************************************/
  
  #ifndef __INCLUDE_NUTTX_FS_UNIONFS_H
  #define __INCLUDE_NUTTX_FS_UNIONFS_H
  
  /****************************************************************************
   * Included Files
   ****************************************************************************/
  
  #include <nuttx/config.h>
  
  #ifdef CONFIG_FS_UNIONFS
  
  /****************************************************************************
   * Pre-processor Definitions
   ****************************************************************************/
  
  /****************************************************************************
   * Type Definitions
   ****************************************************************************/
  
  /****************************************************************************
   * Public Data
   ****************************************************************************/
  
  #ifdef __cplusplus
  #define EXTERN extern "C"
  extern "C"
  {
  #else
  #define EXTERN extern
  #endif
  
  /****************************************************************************
   * Public Function Prototypes
   ****************************************************************************/
  
  /****************************************************************************
   * Name: unionfs_mount
   *
   * Description:
   *   Create and mount a union file system
   *
   * Input Parameters:
   *   fspath1 - The full path to the first file system mountpoint
   *   prefix1 - An optiona prefix that may be applied to make the first
   *             file system appear a some path below the unionfs mountpoint,
   *   fspath2 - The full path to the second file system mountpoint
   *   prefix2 - An optiona prefix that may be applied to make the first
   *             file system appear a some path below the unionfs mountpoint,
   *   mountpt - The full path to the mountpoint for the union file system
   *
   * Returned value:
   *   Zero (OK) is returned if the union file system was correctly created and
   *   mounted.  On any failure, a negated error value will be returned to
   *   indicate the nature of the failure.
   *
   ****************************************************************************/
  
  int unionfs_mount(FAR const char *fspath1, FAR const char *prefix1,
                    FAR const char *fspath2, FAR const char *prefix2,
                    FAR const char *mountpt);
  
  #undef EXTERN
  #ifdef __cplusplus
  }
  #endif
  
  #endif /* CONFIG_FS_UNIONFS */
  #endif /* __INCLUDE_NUTTX_FS_UNIONFS_H */
  