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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#ifndef FS_9P_V9FS_H
24#define FS_9P_V9FS_H
25
26#include <linux/backing-dev.h>
27
28/**
29 * enum p9_session_flags - option flags for each 9P session
30 * @V9FS_PROTO_2000U: whether or not to use 9P2000.u extensions
31 * @V9FS_PROTO_2000L: whether or not to use 9P2000.l extensions
32 * @V9FS_ACCESS_SINGLE: only the mounting user can access the hierarchy
33 * @V9FS_ACCESS_USER: a new attach will be issued for every user (default)
34 * @V9FS_ACCESS_CLIENT: Just like user, but access check is performed on client.
35 * @V9FS_ACCESS_ANY: use a single attach for all users
36 * @V9FS_ACCESS_MASK: bit mask of different ACCESS options
37 * @V9FS_POSIX_ACL: POSIX ACLs are enforced
38 *
39 * Session flags reflect options selected by users at mount time
40 */
41#define V9FS_ACCESS_ANY (V9FS_ACCESS_SINGLE | \
42 V9FS_ACCESS_USER | \
43 V9FS_ACCESS_CLIENT)
44#define V9FS_ACCESS_MASK V9FS_ACCESS_ANY
45#define V9FS_ACL_MASK V9FS_POSIX_ACL
46
47enum p9_session_flags {
48 V9FS_PROTO_2000U = 0x01,
49 V9FS_PROTO_2000L = 0x02,
50 V9FS_ACCESS_SINGLE = 0x04,
51 V9FS_ACCESS_USER = 0x08,
52 V9FS_ACCESS_CLIENT = 0x10,
53 V9FS_POSIX_ACL = 0x20
54};
55
56/* possible values of ->cache */
57/**
58 * enum p9_cache_modes - user specified cache preferences
59 * @CACHE_NONE: do not cache data, dentries, or directory contents (default)
60 * @CACHE_LOOSE: cache data, dentries, and directory contents w/no consistency
61 *
62 * eventually support loose, tight, time, session, default always none
63 */
64
65enum p9_cache_modes {
66 CACHE_NONE,
67 CACHE_MMAP,
68 CACHE_LOOSE,
69 CACHE_FSCACHE,
70};
71
72/**
73 * struct v9fs_session_info - per-instance session information
74 * @flags: session options of type &p9_session_flags
75 * @nodev: set to 1 to disable device mapping
76 * @debug: debug level
77 * @afid: authentication handle
78 * @cache: cache mode of type &p9_cache_modes
79 * @cachetag: the tag of the cache associated with this session
80 * @fscache: session cookie associated with FS-Cache
81 * @options: copy of options string given by user
82 * @uname: string user name to mount hierarchy as
83 * @aname: mount specifier for remote hierarchy
84 * @maxdata: maximum data to be sent/recvd per protocol message
85 * @dfltuid: default numeric userid to mount hierarchy as
86 * @dfltgid: default numeric groupid to mount hierarchy as
87 * @uid: if %V9FS_ACCESS_SINGLE, the numeric uid which mounted the hierarchy
88 * @clnt: reference to 9P network client instantiated for this session
89 * @slist: reference to list of registered 9p sessions
90 *
91 * This structure holds state for each session instance established during
92 * a sys_mount() .
93 *
94 * Bugs: there seems to be a lot of state which could be condensed and/or
95 * removed.
96 */
97
98struct v9fs_session_info {
99 /* options */
100 unsigned char flags;
101 unsigned char nodev;
102 unsigned short debug;
103 unsigned int afid;
104 unsigned int cache;
105#ifdef CONFIG_9P_FSCACHE
106 char *cachetag;
107 struct fscache_cookie *fscache;
108#endif
109
110 char *uname; /* user name to mount as */
111 char *aname; /* name of remote hierarchy being mounted */
112 unsigned int maxdata; /* max data for client interface */
113 kuid_t dfltuid; /* default uid/muid for legacy support */
114 kgid_t dfltgid; /* default gid for legacy support */
115 kuid_t uid; /* if ACCESS_SINGLE, the uid that has access */
116 struct p9_client *clnt; /* 9p client */
117 struct list_head slist; /* list of sessions registered with v9fs */
118 struct backing_dev_info bdi;
119 struct rw_semaphore rename_sem;
120};
121
122/* cache_validity flags */
123#define V9FS_INO_INVALID_ATTR 0x01
124
125struct v9fs_inode {
126#ifdef CONFIG_9P_FSCACHE
127 spinlock_t fscache_lock;
128 struct fscache_cookie *fscache;
129#endif
130 struct p9_qid qid;
131 unsigned int cache_validity;
132 struct p9_fid *writeback_fid;
133 struct mutex v_mutex;
134 struct inode vfs_inode;
135};
136
137static inline struct v9fs_inode *V9FS_I(const struct inode *inode)
138{
139 return container_of(inode, struct v9fs_inode, vfs_inode);
140}
141
142struct p9_fid *v9fs_session_init(struct v9fs_session_info *, const char *,
143 char *);
144extern void v9fs_session_close(struct v9fs_session_info *v9ses);
145extern void v9fs_session_cancel(struct v9fs_session_info *v9ses);
146extern void v9fs_session_begin_cancel(struct v9fs_session_info *v9ses);
147extern struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
148 unsigned int flags);
149extern int v9fs_vfs_unlink(struct inode *i, struct dentry *d);
150extern int v9fs_vfs_rmdir(struct inode *i, struct dentry *d);
151extern int v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
152 struct inode *new_dir, struct dentry *new_dentry);
153extern void v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd,
154 void *p);
155extern struct inode *v9fs_inode_from_fid(struct v9fs_session_info *v9ses,
156 struct p9_fid *fid,
157 struct super_block *sb, int new);
158extern const struct inode_operations v9fs_dir_inode_operations_dotl;
159extern const struct inode_operations v9fs_file_inode_operations_dotl;
160extern const struct inode_operations v9fs_symlink_inode_operations_dotl;
161extern struct inode *v9fs_inode_from_fid_dotl(struct v9fs_session_info *v9ses,
162 struct p9_fid *fid,
163 struct super_block *sb, int new);
164
165/* other default globals */
166#define V9FS_PORT 564
167#define V9FS_DEFUSER "nobody"
168#define V9FS_DEFANAME ""
169#define V9FS_DEFUID KUIDT_INIT(-2)
170#define V9FS_DEFGID KGIDT_INIT(-2)
171
172static inline struct v9fs_session_info *v9fs_inode2v9ses(struct inode *inode)
173{
174 return (inode->i_sb->s_fs_info);
175}
176
177static inline struct v9fs_session_info *v9fs_dentry2v9ses(struct dentry *dentry)
178{
179 return dentry->d_sb->s_fs_info;
180}
181
182static inline int v9fs_proto_dotu(struct v9fs_session_info *v9ses)
183{
184 return v9ses->flags & V9FS_PROTO_2000U;
185}
186
187static inline int v9fs_proto_dotl(struct v9fs_session_info *v9ses)
188{
189 return v9ses->flags & V9FS_PROTO_2000L;
190}
191
192/**
193 * v9fs_get_inode_from_fid - Helper routine to populate an inode by
194 * issuing a attribute request
195 * @v9ses: session information
196 * @fid: fid to issue attribute request for
197 * @sb: superblock on which to create inode
198 *
199 */
200static inline struct inode *
201v9fs_get_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
202 struct super_block *sb)
203{
204 if (v9fs_proto_dotl(v9ses))
205 return v9fs_inode_from_fid_dotl(v9ses, fid, sb, 0);
206 else
207 return v9fs_inode_from_fid(v9ses, fid, sb, 0);
208}
209
210/**
211 * v9fs_get_new_inode_from_fid - Helper routine to populate an inode by
212 * issuing a attribute request
213 * @v9ses: session information
214 * @fid: fid to issue attribute request for
215 * @sb: superblock on which to create inode
216 *
217 */
218static inline struct inode *
219v9fs_get_new_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
220 struct super_block *sb)
221{
222 if (v9fs_proto_dotl(v9ses))
223 return v9fs_inode_from_fid_dotl(v9ses, fid, sb, 1);
224 else
225 return v9fs_inode_from_fid(v9ses, fid, sb, 1);
226}
227
228#endif