fs/aufs/dynop.h

   1 /*
   2  * Copyright (C) 2010-2017 Junjiro R. Okajima
   3  *
   4  * This program, aufs is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program 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
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 /*
  19  * dynamically customizable operations (for regular files only)
  20  */
  21
  22 #ifndef __AUFS_DYNOP_H__
  23 #define __AUFS_DYNOP_H__
  24
  25 #ifdef __KERNEL__
  26
  27 #include <linux/fs.h>
  28 #include <linux/kref.h>
  29
  30 enum {AuDy_AOP, AuDyLast};
  31
  32 struct au_dynop {
  33         int                                             dy_type;
  34         union {
  35                 const void                              *dy_hop;
  36                 const struct address_space_operations   *dy_haop;
  37         };
  38 };
  39
  40 struct au_dykey {
  41         union {
  42                 struct hlist_node       dk_hnode;
  43                 struct rcu_head         dk_rcu;
  44         };
  45         struct au_dynop         dk_op;
  46
  47         /*
  48          * during I am in the branch local array, kref is gotten. when the
  49          * branch is removed, kref is put.
  50          */
  51         struct kref             dk_kref;
  52 };
  53
  54 /* stop unioning since their sizes are very different from each other */
  55 struct au_dyaop {
  56         struct au_dykey                 da_key;
  57         struct address_space_operations da_op; /* not const */
  58 };
  59
  60 /* ---------------------------------------------------------------------- */
  61
  62 /* dynop.c */
  63 struct au_branch;
  64 void au_dy_put(struct au_dykey *key);
  65 int au_dy_iaop(struct inode *inode, aufs_bindex_t bindex,
  66                 struct inode *h_inode);
  67 int au_dy_irefresh(struct inode *inode);
  68 void au_dy_arefresh(int do_dio);
  69
  70 void __init au_dy_init(void);
  71 void au_dy_fin(void);
  72
  73 #endif /* __KERNEL__ */
  74 #endif /* __AUFS_DYNOP_H__ */