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#include <linux/fs_parser.h>
14#include <net/9p/client.h>
15#include <net/9p/transport.h>
16
17/**
18 * enum p9_session_flags - option flags for each 9P session
19 * @V9FS_PROTO_2000U: whether or not to use 9P2000.u extensions
20 * @V9FS_PROTO_2000L: whether or not to use 9P2000.l extensions
21 * @V9FS_ACCESS_SINGLE: only the mounting user can access the hierarchy
22 * @V9FS_ACCESS_USER: a new attach will be issued for every user (default)
23 * @V9FS_ACCESS_CLIENT: Just like user, but access check is performed on client.
24 * @V9FS_ACCESS_ANY: use a single attach for all users
25 * @V9FS_ACCESS_MASK: bit mask of different ACCESS options
26 * @V9FS_POSIX_ACL: POSIX ACLs are enforced
27 *
28 * Session flags reflect options selected by users at mount time
29 */
30#define V9FS_ACCESS_ANY (V9FS_ACCESS_SINGLE | \
31 V9FS_ACCESS_USER | \
32 V9FS_ACCESS_CLIENT)
33#define V9FS_ACCESS_MASK V9FS_ACCESS_ANY
34#define V9FS_ACL_MASK V9FS_POSIX_ACL
35
36enum p9_session_flags {
37 V9FS_PROTO_2000U = 0x01,
38 V9FS_PROTO_2000L = 0x02,
39 V9FS_ACCESS_SINGLE = 0x04,
40 V9FS_ACCESS_USER = 0x08,
41 V9FS_ACCESS_CLIENT = 0x10,
42 V9FS_POSIX_ACL = 0x20,
43 V9FS_NO_XATTR = 0x40,
44 V9FS_IGNORE_QV = 0x80, /* ignore qid.version for cache hints */
45 V9FS_DIRECT_IO = 0x100,
46 V9FS_SYNC = 0x200
47};
48
49/**
50 * enum p9_cache_shortcuts - human readable cache preferences
51 * @CACHE_SC_NONE: disable all caches
52 * @CACHE_SC_READAHEAD: only provide caching for readahead
53 * @CACHE_SC_MMAP: provide caching to enable mmap
54 * @CACHE_SC_LOOSE: non-coherent caching for files and meta data
55 * @CACHE_SC_FSCACHE: persistent non-coherent caching for files and meta-data
56 *
57 */
58
59enum p9_cache_shortcuts {
60 CACHE_SC_NONE = 0b00000000,
61 CACHE_SC_READAHEAD = 0b00000001,
62 CACHE_SC_MMAP = 0b00000101,
63 CACHE_SC_LOOSE = 0b00001111,
64 CACHE_SC_FSCACHE = 0b10001111,
65};
66
67/**
68 * enum p9_cache_bits - possible values of ->cache
69 * @CACHE_NONE: caches disabled
70 * @CACHE_FILE: file caching (open to close)
71 * @CACHE_META: meta-data and directory caching
72 * @CACHE_WRITEBACK: write-back caching for files
73 * @CACHE_LOOSE: don't check cache consistency
74 * @CACHE_FSCACHE: local persistent caches
75 *
76 */
77
78enum p9_cache_bits {
79 CACHE_NONE = 0b00000000,
80 CACHE_FILE = 0b00000001,
81 CACHE_META = 0b00000010,
82 CACHE_WRITEBACK = 0b00000100,
83 CACHE_LOOSE = 0b00001000,
84 CACHE_FSCACHE = 0b10000000,
85};
86
87/**
88 * struct v9fs_session_info - per-instance session information
89 * @flags: session options of type &p9_session_flags
90 * @nodev: set to 1 to disable device mapping
91 * @debug: debug level
92 * @afid: authentication handle
93 * @cache: cache mode of type &p9_cache_bits
94 * @cachetag: the tag of the cache associated with this session
95 * @fscache: session cookie associated with FS-Cache
96 * @uname: string user name to mount hierarchy as
97 * @aname: mount specifier for remote hierarchy
98 * @maxdata: maximum data to be sent/recvd per protocol message
99 * @dfltuid: default numeric userid to mount hierarchy as
100 * @dfltgid: default numeric groupid to mount hierarchy as
101 * @uid: if %V9FS_ACCESS_SINGLE, the numeric uid which mounted the hierarchy
102 * @clnt: reference to 9P network client instantiated for this session
103 * @slist: reference to list of registered 9p sessions
104 *
105 * This structure holds state for each session instance established during
106 * a sys_mount() .
107 *
108 * Bugs: there seems to be a lot of state which could be condensed and/or
109 * removed.
110 */
111
112struct v9fs_session_info {
113 /* options */
114 unsigned int flags;
115 unsigned char nodev;
116 unsigned short debug;
117 unsigned int afid;
118 unsigned int cache;
119#ifdef CONFIG_9P_FSCACHE
120 char *cachetag;
121 struct fscache_volume *fscache;
122#endif
123
124 char *uname; /* user name to mount as */
125 char *aname; /* name of remote hierarchy being mounted */
126 unsigned int maxdata; /* max data for client interface */
127 kuid_t dfltuid; /* default uid/muid for legacy support */
128 kgid_t dfltgid; /* default gid for legacy support */
129 kuid_t uid; /* if ACCESS_SINGLE, the uid that has access */
130 struct p9_client *clnt; /* 9p client */
131 struct list_head slist; /* list of sessions registered with v9fs */
132 struct rw_semaphore rename_sem;
133 long session_lock_timeout; /* retry interval for blocking locks */
134};
135
136/* cache_validity flags */
137#define V9FS_INO_INVALID_ATTR 0x01
138
139struct v9fs_inode {
140 struct netfs_inode netfs; /* Netfslib context and vfs inode */
141 struct p9_qid qid;
142 unsigned int cache_validity;
143 struct mutex v_mutex;
144};
145
146static inline struct v9fs_inode *V9FS_I(const struct inode *inode)
147{
148 return container_of(inode, struct v9fs_inode, netfs.inode);
149}
150
151static inline struct fscache_cookie *v9fs_inode_cookie(struct v9fs_inode *v9inode)
152{
153#ifdef CONFIG_9P_FSCACHE
154 return netfs_i_cookie(ctx: &v9inode->netfs);
155#else
156 return NULL;
157#endif
158}
159
160static inline struct fscache_volume *v9fs_session_cache(struct v9fs_session_info *v9ses)
161{
162#ifdef CONFIG_9P_FSCACHE
163 return v9ses->fscache;
164#else
165 return NULL;
166#endif
167}
168
169extern const struct fs_parameter_spec v9fs_param_spec[];
170
171extern int v9fs_parse_param(struct fs_context *fc, struct fs_parameter *param);
172extern int v9fs_show_options(struct seq_file *m, struct dentry *root);
173
174struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
175 struct fs_context *fc);
176extern void v9fs_session_close(struct v9fs_session_info *v9ses);
177extern void v9fs_session_cancel(struct v9fs_session_info *v9ses);
178extern void v9fs_session_begin_cancel(struct v9fs_session_info *v9ses);
179extern struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
180 unsigned int flags);
181extern int v9fs_vfs_unlink(struct inode *i, struct dentry *d);
182extern int v9fs_vfs_rmdir(struct inode *i, struct dentry *d);
183extern int v9fs_vfs_rename(struct mnt_idmap *idmap,
184 struct inode *old_dir, struct dentry *old_dentry,
185 struct inode *new_dir, struct dentry *new_dentry,
186 unsigned int flags);
187extern struct inode *v9fs_inode_from_fid(struct v9fs_session_info *v9ses,
188 struct p9_fid *fid,
189 struct super_block *sb, int new);
190extern const struct inode_operations v9fs_dir_inode_operations_dotl;
191extern const struct inode_operations v9fs_file_inode_operations_dotl;
192extern const struct inode_operations v9fs_symlink_inode_operations_dotl;
193extern const struct netfs_request_ops v9fs_req_ops;
194extern struct inode *v9fs_inode_from_fid_dotl(struct v9fs_session_info *v9ses,
195 struct p9_fid *fid,
196 struct super_block *sb, int new);
197
198/* other default globals */
199#define V9FS_PORT 564
200#define V9FS_DEFUSER "nobody"
201#define V9FS_DEFANAME ""
202#define V9FS_DEFUID KUIDT_INIT(-2)
203#define V9FS_DEFGID KGIDT_INIT(-2)
204
205static inline struct v9fs_session_info *v9fs_inode2v9ses(struct inode *inode)
206{
207 return inode->i_sb->s_fs_info;
208}
209
210static inline struct v9fs_session_info *v9fs_dentry2v9ses(const struct dentry *dentry)
211{
212 return dentry->d_sb->s_fs_info;
213}
214
215static inline int v9fs_proto_dotu(struct v9fs_session_info *v9ses)
216{
217 return v9ses->flags & V9FS_PROTO_2000U;
218}
219
220static inline int v9fs_proto_dotl(struct v9fs_session_info *v9ses)
221{
222 return v9ses->flags & V9FS_PROTO_2000L;
223}
224
225/**
226 * v9fs_get_inode_from_fid - Helper routine to populate an inode by
227 * issuing a attribute request
228 * @v9ses: session information
229 * @fid: fid to issue attribute request for
230 * @sb: superblock on which to create inode
231 *
232 */
233static inline struct inode *
234v9fs_get_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
235 struct super_block *sb)
236{
237 if (v9fs_proto_dotl(v9ses))
238 return v9fs_inode_from_fid_dotl(v9ses, fid, sb, new: 0);
239 else
240 return v9fs_inode_from_fid(v9ses, fid, sb, new: 0);
241}
242
243/**
244 * v9fs_get_new_inode_from_fid - Helper routine to populate an inode by
245 * issuing a attribute request
246 * @v9ses: session information
247 * @fid: fid to issue attribute request for
248 * @sb: superblock on which to create inode
249 *
250 */
251static inline struct inode *
252v9fs_get_new_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
253 struct super_block *sb)
254{
255 if (v9fs_proto_dotl(v9ses))
256 return v9fs_inode_from_fid_dotl(v9ses, fid, sb, new: 1);
257 else
258 return v9fs_inode_from_fid(v9ses, fid, sb, new: 1);
259}
260
261#endif
262

source code of linux/fs/9p/v9fs.h