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 #include <linux/netfs.h>
13
14 /**
15 * enum p9_session_flags - option flags for each 9P session
16 * @V9FS_PROTO_2000U: whether or not to use 9P2000.u extensions
17 * @V9FS_PROTO_2000L: whether or not to use 9P2000.l extensions
18 * @V9FS_ACCESS_SINGLE: only the mounting user can access the hierarchy
19 * @V9FS_ACCESS_USER: a new attach will be issued for every user (default)
20 * @V9FS_ACCESS_CLIENT: Just like user, but access check is performed on client.
21 * @V9FS_ACCESS_ANY: use a single attach for all users
22 * @V9FS_ACCESS_MASK: bit mask of different ACCESS options
23 * @V9FS_POSIX_ACL: POSIX ACLs are enforced
24 *
25 * Session flags reflect options selected by users at mount time
26 */
27 #define V9FS_ACCESS_ANY (V9FS_ACCESS_SINGLE | \
28 V9FS_ACCESS_USER | \
29 V9FS_ACCESS_CLIENT)
30 #define V9FS_ACCESS_MASK V9FS_ACCESS_ANY
31 #define V9FS_ACL_MASK V9FS_POSIX_ACL
32
33 enum p9_session_flags {
34 V9FS_PROTO_2000U = 0x01,
35 V9FS_PROTO_2000L = 0x02,
36 V9FS_ACCESS_SINGLE = 0x04,
37 V9FS_ACCESS_USER = 0x08,
38 V9FS_ACCESS_CLIENT = 0x10,
39 V9FS_POSIX_ACL = 0x20
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_MMAP,
54 CACHE_LOOSE,
55 CACHE_FSCACHE,
56 nr__p9_cache_modes
57 };
58
59 /**
60 * struct v9fs_session_info - per-instance session information
61 * @flags: session options of type &p9_session_flags
62 * @nodev: set to 1 to disable device mapping
63 * @debug: debug level
64 * @afid: authentication handle
65 * @cache: cache mode of type &p9_cache_modes
66 * @cachetag: the tag of the cache associated with this session
67 * @fscache: session cookie associated with FS-Cache
68 * @uname: string user name to mount hierarchy as
69 * @aname: mount specifier for remote hierarchy
70 * @maxdata: maximum data to be sent/recvd per protocol message
71 * @dfltuid: default numeric userid to mount hierarchy as
72 * @dfltgid: default numeric groupid to mount hierarchy as
73 * @uid: if %V9FS_ACCESS_SINGLE, the numeric uid which mounted the hierarchy
74 * @clnt: reference to 9P network client instantiated for this session
75 * @slist: reference to list of registered 9p sessions
76 *
77 * This structure holds state for each session instance established during
78 * a sys_mount() .
79 *
80 * Bugs: there seems to be a lot of state which could be condensed and/or
81 * removed.
82 */
83
84 struct v9fs_session_info {
85 /* options */
86 unsigned char flags;
87 unsigned char nodev;
88 unsigned short debug;
89 unsigned int afid;
90 unsigned int cache;
91 #ifdef CONFIG_9P_FSCACHE
92 char *cachetag;
93 struct fscache_volume *fscache;
94 #endif
95
96 char *uname; /* user name to mount as */
97 char *aname; /* name of remote hierarchy being mounted */
98 unsigned int maxdata; /* max data for client interface */
99 kuid_t dfltuid; /* default uid/muid for legacy support */
100 kgid_t dfltgid; /* default gid for legacy support */
101 kuid_t uid; /* if ACCESS_SINGLE, the uid that has access */
102 struct p9_client *clnt; /* 9p client */
103 struct list_head slist; /* list of sessions registered with v9fs */
104 struct rw_semaphore rename_sem;
105 long session_lock_timeout; /* retry interval for blocking locks */
106 };
107
108 /* cache_validity flags */
109 #define V9FS_INO_INVALID_ATTR 0x01
110
111 struct v9fs_inode {
112 struct netfs_inode netfs; /* Netfslib context and vfs inode */
113 struct p9_qid qid;
114 unsigned int cache_validity;
115 struct p9_fid *writeback_fid;
116 struct mutex v_mutex;
117 };
118
V9FS_I(const struct inode * inode)119 static inline struct v9fs_inode *V9FS_I(const struct inode *inode)
120 {
121 return container_of(inode, struct v9fs_inode, netfs.inode);
122 }
123
v9fs_inode_cookie(struct v9fs_inode * v9inode)124 static inline struct fscache_cookie *v9fs_inode_cookie(struct v9fs_inode *v9inode)
125 {
126 #ifdef CONFIG_9P_FSCACHE
127 return netfs_i_cookie(&v9inode->netfs);
128 #else
129 return NULL;
130 #endif
131 }
132
v9fs_session_cache(struct v9fs_session_info * v9ses)133 static inline struct fscache_volume *v9fs_session_cache(struct v9fs_session_info *v9ses)
134 {
135 #ifdef CONFIG_9P_FSCACHE
136 return v9ses->fscache;
137 #else
138 return NULL;
139 #endif
140 }
141
142
143 extern int v9fs_show_options(struct seq_file *m, struct dentry *root);
144
145 struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
146 const char *dev_name, char *data);
147 extern void v9fs_session_close(struct v9fs_session_info *v9ses);
148 extern void v9fs_session_cancel(struct v9fs_session_info *v9ses);
149 extern void v9fs_session_begin_cancel(struct v9fs_session_info *v9ses);
150 extern struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
151 unsigned int flags);
152 extern int v9fs_vfs_unlink(struct inode *i, struct dentry *d);
153 extern int v9fs_vfs_rmdir(struct inode *i, struct dentry *d);
154 extern int v9fs_vfs_rename(struct user_namespace *mnt_userns,
155 struct inode *old_dir, struct dentry *old_dentry,
156 struct inode *new_dir, struct dentry *new_dentry,
157 unsigned int flags);
158 extern struct inode *v9fs_inode_from_fid(struct v9fs_session_info *v9ses,
159 struct p9_fid *fid,
160 struct super_block *sb, int new);
161 extern const struct inode_operations v9fs_dir_inode_operations_dotl;
162 extern const struct inode_operations v9fs_file_inode_operations_dotl;
163 extern const struct inode_operations v9fs_symlink_inode_operations_dotl;
164 extern const struct netfs_request_ops v9fs_req_ops;
165 extern struct inode *v9fs_inode_from_fid_dotl(struct v9fs_session_info *v9ses,
166 struct p9_fid *fid,
167 struct super_block *sb, int new);
168
169 /* other default globals */
170 #define V9FS_PORT 564
171 #define V9FS_DEFUSER "nobody"
172 #define V9FS_DEFANAME ""
173 #define V9FS_DEFUID KUIDT_INIT(-2)
174 #define V9FS_DEFGID KGIDT_INIT(-2)
175
v9fs_inode2v9ses(struct inode * inode)176 static inline struct v9fs_session_info *v9fs_inode2v9ses(struct inode *inode)
177 {
178 return inode->i_sb->s_fs_info;
179 }
180
v9fs_dentry2v9ses(struct dentry * dentry)181 static inline struct v9fs_session_info *v9fs_dentry2v9ses(struct dentry *dentry)
182 {
183 return dentry->d_sb->s_fs_info;
184 }
185
v9fs_proto_dotu(struct v9fs_session_info * v9ses)186 static inline int v9fs_proto_dotu(struct v9fs_session_info *v9ses)
187 {
188 return v9ses->flags & V9FS_PROTO_2000U;
189 }
190
v9fs_proto_dotl(struct v9fs_session_info * v9ses)191 static inline int v9fs_proto_dotl(struct v9fs_session_info *v9ses)
192 {
193 return v9ses->flags & V9FS_PROTO_2000L;
194 }
195
196 /**
197 * v9fs_get_inode_from_fid - Helper routine to populate an inode by
198 * issuing a attribute request
199 * @v9ses: session information
200 * @fid: fid to issue attribute request for
201 * @sb: superblock on which to create inode
202 *
203 */
204 static inline struct inode *
v9fs_get_inode_from_fid(struct v9fs_session_info * v9ses,struct p9_fid * fid,struct super_block * sb)205 v9fs_get_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
206 struct super_block *sb)
207 {
208 if (v9fs_proto_dotl(v9ses))
209 return v9fs_inode_from_fid_dotl(v9ses, fid, sb, 0);
210 else
211 return v9fs_inode_from_fid(v9ses, fid, sb, 0);
212 }
213
214 /**
215 * v9fs_get_new_inode_from_fid - Helper routine to populate an inode by
216 * issuing a attribute request
217 * @v9ses: session information
218 * @fid: fid to issue attribute request for
219 * @sb: superblock on which to create inode
220 *
221 */
222 static inline struct inode *
v9fs_get_new_inode_from_fid(struct v9fs_session_info * v9ses,struct p9_fid * fid,struct super_block * sb)223 v9fs_get_new_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
224 struct super_block *sb)
225 {
226 if (v9fs_proto_dotl(v9ses))
227 return v9fs_inode_from_fid_dotl(v9ses, fid, sb, 1);
228 else
229 return v9fs_inode_from_fid(v9ses, fid, sb, 1);
230 }
231
232 #endif
233