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
33enum 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
56enum 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
75enum 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
109struct 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
136struct 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
143static inline struct v9fs_inode *V9FS_I(const struct inode *inode)
144{
145	return container_of(inode, struct v9fs_inode, netfs.inode);
146}
147
148static 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
157static 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
167extern int v9fs_show_options(struct seq_file *m, struct dentry *root);
168
169struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
170				 const char *dev_name, char *data);
171extern void v9fs_session_close(struct v9fs_session_info *v9ses);
172extern void v9fs_session_cancel(struct v9fs_session_info *v9ses);
173extern void v9fs_session_begin_cancel(struct v9fs_session_info *v9ses);
174extern struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
175				      unsigned int flags);
176extern int v9fs_vfs_unlink(struct inode *i, struct dentry *d);
177extern int v9fs_vfs_rmdir(struct inode *i, struct dentry *d);
178extern 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);
182extern struct inode *v9fs_fid_iget(struct super_block *sb, struct p9_fid *fid,
183						bool new);
184extern const struct inode_operations v9fs_dir_inode_operations_dotl;
185extern const struct inode_operations v9fs_file_inode_operations_dotl;
186extern const struct inode_operations v9fs_symlink_inode_operations_dotl;
187extern const struct netfs_request_ops v9fs_req_ops;
188extern 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
198static inline struct v9fs_session_info *v9fs_inode2v9ses(struct inode *inode)
199{
200	return inode->i_sb->s_fs_info;
201}
202
203static inline struct v9fs_session_info *v9fs_dentry2v9ses(struct dentry *dentry)
204{
205	return dentry->d_sb->s_fs_info;
206}
207
208static inline int v9fs_proto_dotu(struct v9fs_session_info *v9ses)
209{
210	return v9ses->flags & V9FS_PROTO_2000U;
211}
212
213static 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 */
226static inline struct inode *
227v9fs_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