fs/9p/fid.h

   1 /*
   2  * V9FS FID Management
   3  *
   4  *  Copyright (C) 2005 by Eric Van Hensbergen <ericvh@gmail.com>
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License version 2
   8  *  as published by the Free Software Foundation.
   9  *
  10  *  This program is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License
  16  *  along with this program; if not, write to:
  17  *  Free Software Foundation
  18  *  51 Franklin Street, Fifth Floor
  19  *  Boston, MA  02111-1301  USA
  20  *
  21  */
  22 #ifndef FS_9P_FID_H
  23 #define FS_9P_FID_H
  24 #include <linux/list.h>
  25
  26 /**
  27  * struct v9fs_dentry - 9p private data stored in dentry d_fsdata
  28  * @lock: protects the fidlist
  29  * @fidlist: list of FIDs currently associated with this dentry
  30  *
  31  * This structure defines the 9p private data associated with
  32  * a particular dentry.  In particular, this private data is used
  33  * to lookup which 9P FID handle should be used for a particular VFS
  34  * operation.  FID handles are associated with dentries instead of
  35  * inodes in order to more closely map functionality to the Plan 9
  36  * expected behavior for FID reclaimation and tracking.
  37  *
  38  * See Also: Mapping FIDs to Linux VFS model in
  39  * Design and Implementation of the Linux 9P File System documentation
  40  */
  41 struct v9fs_dentry {
  42         spinlock_t lock; /* protect fidlist */
  43         struct list_head fidlist;
  44 };
  45
  46 struct p9_fid *v9fs_fid_lookup(struct dentry *dentry);
  47 struct p9_fid *v9fs_fid_clone(struct dentry *dentry);
  48 int v9fs_fid_add(struct dentry *dentry, struct p9_fid *fid);
  49 struct p9_fid *v9fs_writeback_fid(struct dentry *dentry);
  50 #endif