1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * V9FS definitions.
4 *
5 * Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
6 * Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
7 */
8 #ifndef FS_9P_V9FS_H
9 #define FS_9P_V9FS_H
10
11 #include <linux/backing-dev.h>
12
13 /**
14 * enum p9_session_flags - option flags for each 9P session
15 * @V9FS_PROTO_2000U: whether or not to use 9P2000.u extensions
16 * @V9FS_PROTO_2000L: whether or not to use 9P2000.l extensions
17 * @V9FS_ACCESS_SINGLE: only the mounting user can access the hierarchy
18 * @V9FS_ACCESS_USER: a new attach will be issued for every user (default)
19 * @V9FS_ACCESS_CLIENT: Just like user, but access check is performed on client.
20 * @V9FS_ACCESS_ANY: use a single attach for all users
21 * @V9FS_ACCESS_MASK: bit mask of different ACCESS options
22 * @V9FS_POSIX_ACL: POSIX ACLs are enforced
23 *
24 * Session flags reflect options selected by users at mount time
25 */
26 #define V9FS_ACCESS_ANY (V9FS_ACCESS_SINGLE | \
27 V9FS_ACCESS_USER | \
28 V9FS_ACCESS_CLIENT)
29 #define V9FS_ACCESS_MASK V9FS_ACCESS_ANY
30 #define V9FS_ACL_MASK V9FS_POSIX_ACL
31
32 enum p9_session_flags {
33 V9FS_PROTO_2000U = 0x01,
34 V9FS_PROTO_2000L = 0x02,
35 V9FS_ACCESS_SINGLE = 0x04,
36 V9FS_ACCESS_USER = 0x08,
37 V9FS_ACCESS_CLIENT = 0x10,
38 V9FS_POSIX_ACL = 0x20
39 };
40
41 /* possible values of ->cache */
42 /**
43 * enum p9_cache_modes - user specified cache preferences
44 * @CACHE_NONE: do not cache data, dentries, or directory contents (default)
45 * @CACHE_LOOSE: cache data, dentries, and directory contents w/no consistency
46 *
47 * eventually support loose, tight, time, session, default always none
48 */
49
50 enum p9_cache_modes {
51 CACHE_NONE,
52 CACHE_MMAP,
53 CACHE_LOOSE,
54 CACHE_FSCACHE,
55 nr__p9_cache_modes
56 };
57
58 /**
59 * struct v9fs_session_info - per-instance session information
60 * @flags: session options of type &p9_session_flags
61 * @nodev: set to 1 to disable device mapping
62 * @debug: debug level
63 * @afid: authentication handle
64 * @cache: cache mode of type &p9_cache_modes
65 * @cachetag: the tag of the cache associated with this session
66 * @fscache: session cookie associated with FS-Cache
67 * @uname: string user name to mount hierarchy as
68 * @aname: mount specifier for remote hierarchy
69 * @maxdata: maximum data to be sent/recvd per protocol message
70 * @dfltuid: default numeric userid to mount hierarchy as
71 * @dfltgid: default numeric groupid to mount hierarchy as
72 * @uid: if %V9FS_ACCESS_SINGLE, the numeric uid which mounted the hierarchy
73 * @clnt: reference to 9P network client instantiated for this session
74 * @slist: reference to list of registered 9p sessions
75 *
76 * This structure holds state for each session instance established during
77 * a sys_mount() .
78 *
79 * Bugs: there seems to be a lot of state which could be condensed and/or
80 * removed.
81 */
82
83 struct v9fs_session_info {
84 /* options */
85 unsigned char flags;
86 unsigned char nodev;
87 unsigned short debug;
88 unsigned int afid;
89 unsigned int cache;
90 #ifdef CONFIG_9P_FSCACHE
91 char *cachetag;
92 struct fscache_cookie *fscache;
93 #endif
94
95 char *uname; /* user name to mount as */
96 char *aname; /* name of remote hierarchy being mounted */
97 unsigned int maxdata; /* max data for client interface */
98 kuid_t dfltuid; /* default uid/muid for legacy support */
99 kgid_t dfltgid; /* default gid for legacy support */
100 kuid_t uid; /* if ACCESS_SINGLE, the uid that has access */
101 struct p9_client *clnt; /* 9p client */
102 struct list_head slist; /* list of sessions registered with v9fs */
103 struct rw_semaphore rename_sem;
104 long session_lock_timeout; /* retry interval for blocking locks */
105 };
106
107 /* cache_validity flags */
108 #define V9FS_INO_INVALID_ATTR 0x01
109
110 struct v9fs_inode {
111 #ifdef CONFIG_9P_FSCACHE
112 struct mutex fscache_lock;
113 struct fscache_cookie *fscache;
114 #endif
115 struct p9_qid qid;
116 unsigned int cache_validity;
117 struct p9_fid *writeback_fid;
118 struct mutex v_mutex;
119 struct inode vfs_inode;
120 };
121
V9FS_I(const struct inode * inode)122 static inline struct v9fs_inode *V9FS_I(const struct inode *inode)
123 {
124 return container_of(inode, struct v9fs_inode, vfs_inode);
125 }
126
v9fs_inode_cookie(struct v9fs_inode * v9inode)127 static inline struct fscache_cookie *v9fs_inode_cookie(struct v9fs_inode *v9inode)
128 {
129 #ifdef CONFIG_9P_FSCACHE
130 return v9inode->fscache;
131 #else
132 return NULL;
133 #endif
134 }
135
136 extern int v9fs_show_options(struct seq_file *m, struct dentry *root);
137
138 struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
139 const char *dev_name, char *data);
140 extern void v9fs_session_close(struct v9fs_session_info *v9ses);
141 extern void v9fs_session_cancel(struct v9fs_session_info *v9ses);
142 extern void v9fs_session_begin_cancel(struct v9fs_session_info *v9ses);
143 extern struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
144 unsigned int flags);
145 extern int v9fs_vfs_unlink(struct inode *i, struct dentry *d);
146 extern int v9fs_vfs_rmdir(struct inode *i, struct dentry *d);
147 extern int v9fs_vfs_rename(struct user_namespace *mnt_userns,
148 struct inode *old_dir, struct dentry *old_dentry,
149 struct inode *new_dir, struct dentry *new_dentry,
150 unsigned int flags);
151 extern struct inode *v9fs_inode_from_fid(struct v9fs_session_info *v9ses,
152 struct p9_fid *fid,
153 struct super_block *sb, int new);
154 extern const struct inode_operations v9fs_dir_inode_operations_dotl;
155 extern const struct inode_operations v9fs_file_inode_operations_dotl;
156 extern const struct inode_operations v9fs_symlink_inode_operations_dotl;
157 extern struct inode *v9fs_inode_from_fid_dotl(struct v9fs_session_info *v9ses,
158 struct p9_fid *fid,
159 struct super_block *sb, int new);
160
161 /* other default globals */
162 #define V9FS_PORT 564
163 #define V9FS_DEFUSER "nobody"
164 #define V9FS_DEFANAME ""
165 #define V9FS_DEFUID KUIDT_INIT(-2)
166 #define V9FS_DEFGID KGIDT_INIT(-2)
167
v9fs_inode2v9ses(struct inode * inode)168 static inline struct v9fs_session_info *v9fs_inode2v9ses(struct inode *inode)
169 {
170 return inode->i_sb->s_fs_info;
171 }
172
v9fs_dentry2v9ses(struct dentry * dentry)173 static inline struct v9fs_session_info *v9fs_dentry2v9ses(struct dentry *dentry)
174 {
175 return dentry->d_sb->s_fs_info;
176 }
177
v9fs_proto_dotu(struct v9fs_session_info * v9ses)178 static inline int v9fs_proto_dotu(struct v9fs_session_info *v9ses)
179 {
180 return v9ses->flags & V9FS_PROTO_2000U;
181 }
182
v9fs_proto_dotl(struct v9fs_session_info * v9ses)183 static inline int v9fs_proto_dotl(struct v9fs_session_info *v9ses)
184 {
185 return v9ses->flags & V9FS_PROTO_2000L;
186 }
187
188 /**
189 * v9fs_get_inode_from_fid - Helper routine to populate an inode by
190 * issuing a attribute request
191 * @v9ses: session information
192 * @fid: fid to issue attribute request for
193 * @sb: superblock on which to create inode
194 *
195 */
196 static inline struct inode *
v9fs_get_inode_from_fid(struct v9fs_session_info * v9ses,struct p9_fid * fid,struct super_block * sb)197 v9fs_get_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
198 struct super_block *sb)
199 {
200 if (v9fs_proto_dotl(v9ses))
201 return v9fs_inode_from_fid_dotl(v9ses, fid, sb, 0);
202 else
203 return v9fs_inode_from_fid(v9ses, fid, sb, 0);
204 }
205
206 /**
207 * v9fs_get_new_inode_from_fid - Helper routine to populate an inode by
208 * issuing a attribute request
209 * @v9ses: session information
210 * @fid: fid to issue attribute request for
211 * @sb: superblock on which to create inode
212 *
213 */
214 static inline struct inode *
v9fs_get_new_inode_from_fid(struct v9fs_session_info * v9ses,struct p9_fid * fid,struct super_block * sb)215 v9fs_get_new_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
216 struct super_block *sb)
217 {
218 if (v9fs_proto_dotl(v9ses))
219 return v9fs_inode_from_fid_dotl(v9ses, fid, sb, 1);
220 else
221 return v9fs_inode_from_fid(v9ses, fid, sb, 1);
222 }
223
224 #endif
225