aboutsummaryrefslogtreecommitdiff
path: root/fs/9p/v9fs.h
blob: 21bd803a3cc0e84c541e85de037c670c38902718 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
/*
 * V9FS definitions.
 *
 *  Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
 *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2
 *  as published by the Free Software Foundation.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to:
 *  Free Software Foundation
 *  51 Franklin Street, Fifth Floor
 *  Boston, MA  02111-1301  USA
 *
 */
#include <linux/backing-dev.h>

/**
 * enum p9_session_flags - option flags for each 9P session
 * @V9FS_PROTO_2000U: whether or not to use 9P2000.u extensions
 * @V9FS_PROTO_2000L: whether or not to use 9P2000.l extensions
 * @V9FS_ACCESS_SINGLE: only the mounting user can access the hierarchy
 * @V9FS_ACCESS_USER: a new attach will be issued for every user (default)
 * @V9FS_ACCESS_CLIENT: Just like user, but access check is performed on client.
 * @V9FS_ACCESS_ANY: use a single attach for all users
 * @V9FS_ACCESS_MASK: bit mask of different ACCESS options
 * @V9FS_POSIX_ACL: POSIX ACLs are enforced
 *
 * Session flags reflect options selected by users at mount time
 */
#define	V9FS_ACCESS_ANY (V9FS_ACCESS_SINGLE | \
			 V9FS_ACCESS_USER |   \
			 V9FS_ACCESS_CLIENT)
#define V9FS_ACCESS_MASK V9FS_ACCESS_ANY
#define V9FS_ACL_MASK V9FS_POSIX_ACL

enum p9_session_flags {
	V9FS_PROTO_2000U	= 0x01,
	V9FS_PROTO_2000L	= 0x02,
	V9FS_ACCESS_SINGLE	= 0x04,
	V9FS_ACCESS_USER	= 0x08,
	V9FS_ACCESS_CLIENT	= 0x10,
	V9FS_POSIX_ACL		= 0x20
};

/* possible values of ->cache */
/**
 * enum p9_cache_modes - user specified cache preferences
 * @CACHE_NONE: do not cache data, dentries, or directory contents (default)
 * @CACHE_LOOSE: cache data, dentries, and directory contents w/no consistency
 *
 * eventually support loose, tight, time, session, default always none
 */

enum p9_cache_modes {
	CACHE_NONE,
	CACHE_LOOSE,
	CACHE_FSCACHE,
};

/**
 * struct v9fs_session_info - per-instance session information
 * @flags: session options of type &p9_session_flags
 * @nodev: set to 1 to disable device mapping
 * @debug: debug level
 * @afid: authentication handle
 * @cache: cache mode of type &p9_cache_modes
 * @cachetag: the tag of the cache associated with this session
 * @fscache: session cookie associated with FS-Cache
 * @options: copy of options string given by user
 * @uname: string user name to mount hierarchy as
 * @aname: mount specifier for remote hierarchy
 * @maxdata: maximum data to be sent/recvd per protocol message
 * @dfltuid: default numeric userid to mount hierarchy as
 * @dfltgid: default numeric groupid to mount hierarchy as
 * @uid: if %V9FS_ACCESS_SINGLE, the numeric uid which mounted the hierarchy
 * @clnt: reference to 9P network client instantiated for this session
 * @slist: reference to list of registered 9p sessions
 *
 * This structure holds state for each session instance established during
 * a sys_mount() .
 *
 * Bugs: there seems to be a lot of state which could be condensed and/or
 * removed.
 */

struct v9fs_session_info {
	/* options */
	unsigned char flags;
	unsigned char nodev;
	unsigned short debug;
	unsigned int afid;
	unsigned int cache;
#ifdef CONFIG_9P_FSCACHE
	char *cachetag;
	struct fscache_cookie *fscache;
#endif

	char *uname;		/* user name to mount as */
	char *aname;		/* name of remote hierarchy being mounted */
	unsigned int maxdata;	/* max data for client interface */
	unsigned int dfltuid;	/* default uid/muid for legacy support */
	unsigned int dfltgid;	/* default gid for legacy support */
	u32 uid;		/* if ACCESS_SINGLE, the uid that has access */
	struct p9_client *clnt;	/* 9p client */
	struct list_head slist; /* list of sessions registered with v9fs */
	struct backing_dev_info bdi;
	struct rw_semaphore rename_sem;
	struct p9_fid *root_fid; /* Used for file system sync */
};

struct p9_fid *v9fs_session_init(struct v9fs_session_info *, const char *,
									char *);
extern void v9fs_session_close(struct v9fs_session_info *v9ses);
extern void v9fs_session_cancel(struct v9fs_session_info *v9ses);
extern void v9fs_session_begin_cancel(struct v9fs_session_info *v9ses);
extern struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
			struct nameidata *nameidata);
extern int v9fs_vfs_unlink(struct inode *i, struct dentry *d);
extern int v9fs_vfs_rmdir(struct inode *i, struct dentry *d);
extern int v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
			struct inode *new_dir, struct dentry *new_dentry);
extern void v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd,
			void *p);
extern struct inode *v9fs_inode(struct v9fs_session_info *v9ses,
			struct p9_fid *fid,
			struct super_block *sb);

extern const struct inode_operations v9fs_dir_inode_operations_dotl;
extern const struct inode_operations v9fs_file_inode_operations_dotl;
extern const struct inode_operations v9fs_symlink_inode_operations_dotl;
extern struct inode *v9fs_inode_dotl(struct v9fs_session_info *v9ses,
			struct p9_fid *fid,
			struct super_block *sb);

/* other default globals */
#define V9FS_PORT	564
#define V9FS_DEFUSER	"nobody"
#define V9FS_DEFANAME	""
#define V9FS_DEFUID	(-2)
#define V9FS_DEFGID	(-2)

static inline struct v9fs_session_info *v9fs_inode2v9ses(struct inode *inode)
{
	return (inode->i_sb->s_fs_info);
}

static inline int v9fs_proto_dotu(struct v9fs_session_info *v9ses)
{
	return v9ses->flags & V9FS_PROTO_2000U;
}

static inline int v9fs_proto_dotl(struct v9fs_session_info *v9ses)
{
	return v9ses->flags & V9FS_PROTO_2000L;
}

/**
 * v9fs_inode_from_fid - Helper routine to populate an inode by
 * issuing a attribute request
 * @v9ses: session information
 * @fid: fid to issue attribute request for
 * @sb: superblock on which to create inode
 *
 */
static inline struct inode *
v9fs_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
				struct super_block *sb)
{
	if (v9fs_proto_dotl(v9ses))
		return v9fs_inode_dotl(v9ses, fid, sb);
	else
		return v9fs_inode(v9ses, fid, sb);
}