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 V9FS_NO_XATTR = 0x40,
41 V9FS_IGNORE_QV = 0x80, /* ignore qid.version for cache hints */
42 V9FS_DIRECT_IO = 0x100,
43 V9FS_SYNC = 0x200
44 };
45
46 /**
47 * enum p9_cache_shortcuts - human readable cache preferences
48 * @CACHE_SC_NONE: disable all caches
49 * @CACHE_SC_READAHEAD: only provide caching for readahead
50 * @CACHE_SC_MMAP: provide caching to enable mmap
51 * @CACHE_SC_LOOSE: non-coherent caching for files and meta data
52 * @CACHE_SC_FSCACHE: persistent non-coherent caching for files and meta-data
53 *
54 */
55
56 enum p9_cache_shortcuts {
57 CACHE_SC_NONE = 0b00000000,
58 CACHE_SC_READAHEAD = 0b00000001,
59 CACHE_SC_MMAP = 0b00000101,
60 CACHE_SC_LOOSE = 0b00001111,
61 CACHE_SC_FSCACHE = 0b10001111,
62 };
63
64 /**
65 * enum p9_cache_bits - possible values of ->cache
66 * @CACHE_NONE: caches disabled
67 * @CACHE_FILE: file caching (open to close)
68 * @CACHE_META: meta-data and directory caching
69 * @CACHE_WRITEBACK: write-back caching for files
70 * @CACHE_LOOSE: don't check cache consistency
71 * @CACHE_FSCACHE: local persistent caches
72 *
73 */
74
75 enum p9_cache_bits {
76 CACHE_NONE = 0b00000000,
77 CACHE_FILE = 0b00000001,
78 CACHE_META = 0b00000010,
79 CACHE_WRITEBACK = 0b00000100,
80 CACHE_LOOSE = 0b00001000,
81 CACHE_FSCACHE = 0b10000000,
82 };
83
84 /**
85 * struct v9fs_session_info - per-instance session information
86 * @flags: session options of type &p9_session_flags
87 * @nodev: set to 1 to disable device mapping
88 * @debug: debug level
89 * @afid: authentication handle
90 * @cache: cache mode of type &p9_cache_bits
91 * @cachetag: the tag of the cache associated with this session
92 * @fscache: session cookie associated with FS-Cache
93 * @uname: string user name to mount hierarchy as
94 * @aname: mount specifier for remote hierarchy
95 * @maxdata: maximum data to be sent/recvd per protocol message
96 * @dfltuid: default numeric userid to mount hierarchy as
97 * @dfltgid: default numeric groupid to mount hierarchy as
98 * @uid: if %V9FS_ACCESS_SINGLE, the numeric uid which mounted the hierarchy
99 * @clnt: reference to 9P network client instantiated for this session
100 * @slist: reference to list of registered 9p sessions
101 *
102 * This structure holds state for each session instance established during
103 * a sys_mount() .
104 *
105 * Bugs: there seems to be a lot of state which could be condensed and/or
106 * removed.
107 */
108
109 struct v9fs_session_info {
110 /* options */
111 unsigned int flags;
112 unsigned char nodev;
113 unsigned short debug;
114 unsigned int afid;
115 unsigned int cache;
116 #ifdef CONFIG_9P_FSCACHE
117 char *cachetag;
118 struct fscache_volume *fscache;
119 #endif
120
121 char *uname; /* user name to mount as */
122 char *aname; /* name of remote hierarchy being mounted */
123 unsigned int maxdata; /* max data for client interface */
124 kuid_t dfltuid; /* default uid/muid for legacy support */
125 kgid_t dfltgid; /* default gid for legacy support */
126 kuid_t uid; /* if ACCESS_SINGLE, the uid that has access */
127 struct p9_client *clnt; /* 9p client */
128 struct list_head slist; /* list of sessions registered with v9fs */
129 struct rw_semaphore rename_sem;
130 long session_lock_timeout; /* retry interval for blocking locks */
131 };
132
133 /* cache_validity flags */
134 #define V9FS_INO_INVALID_ATTR 0x01
135
136 struct v9fs_inode {
137 struct netfs_inode netfs; /* Netfslib context and vfs inode */
138 struct p9_qid qid;
139 unsigned int cache_validity;
140 struct mutex v_mutex;
141 };
142
143 static inline struct v9fs_inode *V9FS_I(const struct inode *inode)
144 {
145 return container_of(inode, struct v9fs_inode, netfs.inode);
146 }
147
148 static inline struct fscache_cookie *v9fs_inode_cookie(struct v9fs_inode *v9inode)
149 {
150 #ifdef CONFIG_9P_FSCACHE
151 return netfs_i_cookie(&v9inode->netfs);
152 #else
153 return NULL;
154 #endif
155 }
156
157 static inline struct fscache_volume *v9fs_session_cache(struct v9fs_session_info *v9ses)
158 {
159 #ifdef CONFIG_9P_FSCACHE
160 return v9ses->fscache;
161 #else
162 return NULL;
163 #endif
164 }
165
166
167 extern int v9fs_show_options(struct seq_file *m, struct dentry *root);
168
169 struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
170 const char *dev_name, char *data);
171 extern void v9fs_session_close(struct v9fs_session_info *v9ses);
172 extern void v9fs_session_cancel(struct v9fs_session_info *v9ses);
173 extern void v9fs_session_begin_cancel(struct v9fs_session_info *v9ses);
174 extern struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
175 unsigned int flags);
176 extern int v9fs_vfs_unlink(struct inode *i, struct dentry *d);
177 extern int v9fs_vfs_rmdir(struct inode *i, struct dentry *d);
178 extern int v9fs_vfs_rename(struct mnt_idmap *idmap,
179 struct inode *old_dir, struct dentry *old_dentry,
180 struct inode *new_dir, struct dentry *new_dentry,
181 unsigned int flags);
182 extern struct inode *v9fs_fid_iget(struct super_block *sb, struct p9_fid *fid,
183 bool new);
184 extern const struct inode_operations v9fs_dir_inode_operations_dotl;
185 extern const struct inode_operations v9fs_file_inode_operations_dotl;
186 extern const struct inode_operations v9fs_symlink_inode_operations_dotl;
187 extern const struct netfs_request_ops v9fs_req_ops;
188 extern struct inode *v9fs_fid_iget_dotl(struct super_block *sb,
189 struct p9_fid *fid, bool new);
190
191 /* other default globals */
192 #define V9FS_PORT 564
193 #define V9FS_DEFUSER "nobody"
194 #define V9FS_DEFANAME ""
195 #define V9FS_DEFUID KUIDT_INIT(-2)
196 #define V9FS_DEFGID KGIDT_INIT(-2)
197
198 static inline struct v9fs_session_info *v9fs_inode2v9ses(struct inode *inode)
199 {
200 return inode->i_sb->s_fs_info;
201 }
202
203 static inline struct v9fs_session_info *v9fs_dentry2v9ses(struct dentry *dentry)
204 {
205 return dentry->d_sb->s_fs_info;
206 }
207
208 static inline int v9fs_proto_dotu(struct v9fs_session_info *v9ses)
209 {
210 return v9ses->flags & V9FS_PROTO_2000U;
211 }
212
213 static inline int v9fs_proto_dotl(struct v9fs_session_info *v9ses)
214 {
215 return v9ses->flags & V9FS_PROTO_2000L;
216 }
217
218 /**
219 * v9fs_get_inode_from_fid - Helper routine to populate an inode by
220 * issuing a attribute request
221 * @v9ses: session information
222 * @fid: fid to issue attribute request for
223 * @sb: superblock on which to create inode
224 *
225 */
226 static inline struct inode *
227 v9fs_get_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
228 struct super_block *sb, bool new)
229 {
230 if (v9fs_proto_dotl(v9ses))
231 return v9fs_fid_iget_dotl(sb, fid, new);
232 else
233 return v9fs_fid_iget(sb, fid, new);
234 }
235
236 #endif
237
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