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
51