text: /* SPDX-License-Identifier: GPL-2.0 */
  /*
   * Copyright (C) 2010-2020 Junjiro R. Okajima
   *
   * This program, aufs is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; either version 2 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 General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program.  If not, see <http://www.gnu.org/licenses/>.
   */
  
  /*
   * dynamically customizable operations (for regular files only)
   */
  
  #ifndef __AUFS_DYNOP_H__
  #define __AUFS_DYNOP_H__
  
  #ifdef __KERNEL__
  
  #include <linux/fs.h>
  #include <linux/kref.h>
  
  enum {AuDy_AOP, AuDyLast};
  
  struct au_dynop {
  	int						dy_type;
  	union {
  		const void				*dy_hop;
  		const struct address_space_operations	*dy_haop;
  	};
  };
  
  struct au_dykey {
  	union {
  		struct hlist_bl_node	dk_hnode;
  		struct rcu_head		dk_rcu;
  	};
  	struct au_dynop		dk_op;
  
  	/*
  	 * during I am in the branch local array, kref is gotten. when the
  	 * branch is removed, kref is put.
  	 */
  	struct kref		dk_kref;
  };
  
  /* stop unioning since their sizes are very different from each other */
  struct au_dyaop {
  	struct au_dykey			da_key;
  	struct address_space_operations	da_op; /* not const */
  };
  /* make sure that 'struct au_dykey *' can be any type */
  static_assert(!offsetof(struct au_dyaop, da_key));
  
  /* ---------------------------------------------------------------------- */
  
  /* dynop.c */
  struct au_branch;
  void au_dy_put(struct au_dykey *key);
  int au_dy_iaop(struct inode *inode, aufs_bindex_t bindex,
  		struct inode *h_inode);
  int au_dy_irefresh(struct inode *inode);
  void au_dy_arefresh(int do_dio);
  
  void __init au_dy_init(void);
  void au_dy_fin(void);
  
  #endif /* __KERNEL__ */
  #endif /* __AUFS_DYNOP_H__ */
  