xref: /openbmc/linux/fs/9p/v9fs.h (revision 367b8112)
1 /*
2  * V9FS definitions.
3  *
4  *  Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
5  *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
6  *
7  *  This program is free software; you can redistribute it and/or modify
8  *  it under the terms of the GNU General Public License version 2
9  *  as published by the Free Software Foundation.
10  *
11  *  This program is distributed in the hope that it will be useful,
12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  *  GNU General Public License for more details.
15  *
16  *  You should have received a copy of the GNU General Public License
17  *  along with this program; if not, write to:
18  *  Free Software Foundation
19  *  51 Franklin Street, Fifth Floor
20  *  Boston, MA  02111-1301  USA
21  *
22  */
23 
24 /**
25  * enum p9_session_flags - option flags for each 9P session
26  * @V9FS_EXTENDED: whether or not to use 9P2000.u extensions
27  * @V9FS_ACCESS_SINGLE: only the mounting user can access the hierarchy
28  * @V9FS_ACCESS_USER: a new attach will be issued for every user (default)
29  * @V9FS_ACCESS_ANY: use a single attach for all users
30  * @V9FS_ACCESS_MASK: bit mask of different ACCESS options
31  *
32  * Session flags reflect options selected by users at mount time
33  */
34 enum p9_session_flags {
35 	V9FS_EXTENDED		= 0x01,
36 	V9FS_ACCESS_SINGLE	= 0x02,
37 	V9FS_ACCESS_USER	= 0x04,
38 	V9FS_ACCESS_ANY		= 0x06,
39 	V9FS_ACCESS_MASK	= 0x06,
40 };
41 
42 /* possible values of ->cache */
43 /**
44  * enum p9_cache_modes - user specified cache preferences
45  * @CACHE_NONE: do not cache data, dentries, or directory contents (default)
46  * @CACHE_LOOSE: cache data, dentries, and directory contents w/no consistency
47  *
48  * eventually support loose, tight, time, session, default always none
49  */
50 
51 enum p9_cache_modes {
52 	CACHE_NONE,
53 	CACHE_LOOSE,
54 };
55 
56 /**
57  * struct v9fs_session_info - per-instance session information
58  * @flags: session options of type &p9_session_flags
59  * @nodev: set to 1 to disable device mapping
60  * @debug: debug level
61  * @afid: authentication handle
62  * @cache: cache mode of type &p9_cache_modes
63  * @options: copy of options string given by user
64  * @uname: string user name to mount hierarchy as
65  * @aname: mount specifier for remote hierarchy
66  * @maxdata: maximum data to be sent/recvd per protocol message
67  * @dfltuid: default numeric userid to mount hierarchy as
68  * @dfltgid: default numeric groupid to mount hierarchy as
69  * @uid: if %V9FS_ACCESS_SINGLE, the numeric uid which mounted the hierarchy
70  * @clnt: reference to 9P network client instantiated for this session
71  * @debugfs_dir: reference to debugfs_dir which can be used for add'l debug
72  *
73  * This structure holds state for each session instance established during
74  * a sys_mount() .
75  *
76  * Bugs: there seems to be a lot of state which could be condensed and/or
77  * removed.
78  */
79 
80 struct v9fs_session_info {
81 	/* options */
82 	unsigned char flags;
83 	unsigned char nodev;
84 	unsigned short debug;
85 	unsigned int afid;
86 	unsigned int cache;
87 
88 	char *options;		/* copy of mount options */
89 	char *uname;		/* user name to mount as */
90 	char *aname;		/* name of remote hierarchy being mounted */
91 	unsigned int maxdata;	/* max data for client interface */
92 	unsigned int dfltuid;	/* default uid/muid for legacy support */
93 	unsigned int dfltgid;	/* default gid for legacy support */
94 	u32 uid;		/* if ACCESS_SINGLE, the uid that has access */
95 	struct p9_client *clnt;	/* 9p client */
96 	struct dentry *debugfs_dir;
97 };
98 
99 extern struct dentry *v9fs_debugfs_root;
100 
101 struct p9_fid *v9fs_session_init(struct v9fs_session_info *, const char *,
102 									char *);
103 void v9fs_session_close(struct v9fs_session_info *v9ses);
104 void v9fs_session_cancel(struct v9fs_session_info *v9ses);
105 
106 #define V9FS_MAGIC 0x01021997
107 
108 /* other default globals */
109 #define V9FS_PORT	564
110 #define V9FS_DEFUSER	"nobody"
111 #define V9FS_DEFANAME	""
112 #define V9FS_DEFUID	(-2)
113 #define V9FS_DEFGID	(-2)
114 
115 static inline struct v9fs_session_info *v9fs_inode2v9ses(struct inode *inode)
116 {
117 	return (inode->i_sb->s_fs_info);
118 }
119 
120 static inline int v9fs_extended(struct v9fs_session_info *v9ses)
121 {
122 	return v9ses->flags & V9FS_EXTENDED;
123 }
124