fs/aufs/hfsplus.c

   1 /*
   2  * Copyright (C) 2010-2016 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  * special support for filesystems which aqucires an inode mutex
  20  * at final closing a file, eg, hfsplus.
  21  *
  22  * This trick is very simple and stupid, just to open the file before really
  23  * neceeary open to tell hfsplus that this is not the final closing.
  24  * The caller should call au_h_open_pre() after acquiring the inode mutex,
  25  * and au_h_open_post() after releasing it.
  26  */
  27
  28 #include "aufs.h"
  29
  30 struct file *au_h_open_pre(struct dentry *dentry, aufs_bindex_t bindex,
  31                            int force_wr)
  32 {
  33         struct file *h_file;
  34         struct dentry *h_dentry;
  35
  36         h_dentry = au_h_dptr(dentry, bindex);
  37         AuDebugOn(!h_dentry);
  38         AuDebugOn(d_is_negative(h_dentry));
  39
  40         h_file = NULL;
  41         if (au_test_hfsplus(h_dentry->d_sb)
  42             && d_is_reg(h_dentry))
  43                 h_file = au_h_open(dentry, bindex,
  44                                    O_RDONLY | O_NOATIME | O_LARGEFILE,
  45                                    /*file*/NULL, force_wr);
  46         return h_file;
  47 }
  48
  49 void au_h_open_post(struct dentry *dentry, aufs_bindex_t bindex,
  50                     struct file *h_file)
  51 {
  52         if (h_file) {
  53                 fput(h_file);
  54                 au_sbr_put(dentry->d_sb, bindex);
  55         }
  56 }