LXR linux/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 */
  41struct v9fs_dentry {
  42        spinlock_t lock; /* protect fidlist */
  43        struct list_head fidlist;
  44};
  45
  46struct p9_fid *v9fs_fid_lookup(struct dentry *dentry);
  47struct p9_fid *v9fs_fid_clone(struct dentry *dentry);
  48int v9fs_fid_add(struct dentry *dentry, struct p9_fid *fid);
  49struct p9_fid *v9fs_writeback_fid(struct dentry *dentry);
  50#endif
  51