1/*
2 * V9FS definitions.
3 *
4 *  Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
5 *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
6 *
7 *  This program is free software; you can redistribute it and/or modify
8 *  it under the terms of the GNU General Public License version 2
9 *  as published by the Free Software Foundation.
10 *
11 *  This program is distributed in the hope that it will be useful,
12 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
13 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 *  GNU General Public License for more details.
15 *
16 *  You should have received a copy of the GNU General Public License
17 *  along with this program; if not, write to:
18 *  Free Software Foundation
19 *  51 Franklin Street, Fifth Floor
20 *  Boston, MA  02111-1301  USA
21 *
22 */
23#ifndef FS_9P_V9FS_H
24#define FS_9P_V9FS_H
25
26#include <linux/backing-dev.h>
27
28/**
29 * enum p9_session_flags - option flags for each 9P session
30 * @V9FS_PROTO_2000U: whether or not to use 9P2000.u extensions
31 * @V9FS_PROTO_2000L: whether or not to use 9P2000.l extensions
32 * @V9FS_ACCESS_SINGLE: only the mounting user can access the hierarchy
33 * @V9FS_ACCESS_USER: a new attach will be issued for every user (default)
34 * @V9FS_ACCESS_CLIENT: Just like user, but access check is performed on client.
35 * @V9FS_ACCESS_ANY: use a single attach for all users
36 * @V9FS_ACCESS_MASK: bit mask of different ACCESS options
37 * @V9FS_POSIX_ACL: POSIX ACLs are enforced
38 *
39 * Session flags reflect options selected by users at mount time
40 */
41#define	V9FS_ACCESS_ANY (V9FS_ACCESS_SINGLE | \
42			 V9FS_ACCESS_USER |   \
43			 V9FS_ACCESS_CLIENT)
44#define V9FS_ACCESS_MASK V9FS_ACCESS_ANY
45#define V9FS_ACL_MASK V9FS_POSIX_ACL
46
47enum p9_session_flags {
48	V9FS_PROTO_2000U	= 0x01,
49	V9FS_PROTO_2000L	= 0x02,
50	V9FS_ACCESS_SINGLE	= 0x04,
51	V9FS_ACCESS_USER	= 0x08,
52	V9FS_ACCESS_CLIENT	= 0x10,
53	V9FS_POSIX_ACL		= 0x20
54};
55
56/* possible values of ->cache */
57/**
58 * enum p9_cache_modes - user specified cache preferences
59 * @CACHE_NONE: do not cache data, dentries, or directory contents (default)
60 * @CACHE_LOOSE: cache data, dentries, and directory contents w/no consistency
61 *
62 * eventually support loose, tight, time, session, default always none
63 */
64
65enum p9_cache_modes {
66	CACHE_NONE,
67	CACHE_MMAP,
68	CACHE_LOOSE,
69	CACHE_FSCACHE,
70};
71
72/**
73 * struct v9fs_session_info - per-instance session information
74 * @flags: session options of type &p9_session_flags
75 * @nodev: set to 1 to disable device mapping
76 * @debug: debug level
77 * @afid: authentication handle
78 * @cache: cache mode of type &p9_cache_modes
79 * @cachetag: the tag of the cache associated with this session
80 * @fscache: session cookie associated with FS-Cache
81 * @uname: string user name to mount hierarchy as
82 * @aname: mount specifier for remote hierarchy
83 * @maxdata: maximum data to be sent/recvd per protocol message
84 * @dfltuid: default numeric userid to mount hierarchy as
85 * @dfltgid: default numeric groupid to mount hierarchy as
86 * @uid: if %V9FS_ACCESS_SINGLE, the numeric uid which mounted the hierarchy
87 * @clnt: reference to 9P network client instantiated for this session
88 * @slist: reference to list of registered 9p sessions
89 *
90 * This structure holds state for each session instance established during
91 * a sys_mount() .
92 *
93 * Bugs: there seems to be a lot of state which could be condensed and/or
94 * removed.
95 */
96
97struct v9fs_session_info {
98	/* options */
99	unsigned char flags;
100	unsigned char nodev;
101	unsigned short debug;
102	unsigned int afid;
103	unsigned int cache;
104#ifdef CONFIG_9P_FSCACHE
105	char *cachetag;
106	struct fscache_cookie *fscache;
107#endif
108
109	char *uname;		/* user name to mount as */
110	char *aname;		/* name of remote hierarchy being mounted */
111	unsigned int maxdata;	/* max data for client interface */
112	kuid_t dfltuid;		/* default uid/muid for legacy support */
113	kgid_t dfltgid;		/* default gid for legacy support */
114	kuid_t uid;		/* if ACCESS_SINGLE, the uid that has access */
115	struct p9_client *clnt;	/* 9p client */
116	struct list_head slist; /* list of sessions registered with v9fs */
117	struct backing_dev_info bdi;
118	struct rw_semaphore rename_sem;
119};
120
121/* cache_validity flags */
122#define V9FS_INO_INVALID_ATTR 0x01
123
124struct v9fs_inode {
125#ifdef CONFIG_9P_FSCACHE
126	spinlock_t fscache_lock;
127	struct fscache_cookie *fscache;
128#endif
129	struct p9_qid qid;
130	unsigned int cache_validity;
131	struct p9_fid *writeback_fid;
132	struct mutex v_mutex;
133	struct inode vfs_inode;
134};
135
136static inline struct v9fs_inode *V9FS_I(const struct inode *inode)
137{
138	return container_of(inode, struct v9fs_inode, vfs_inode);
139}
140
141struct p9_fid *v9fs_session_init(struct v9fs_session_info *, const char *,
142									char *);
143extern void v9fs_session_close(struct v9fs_session_info *v9ses);
144extern void v9fs_session_cancel(struct v9fs_session_info *v9ses);
145extern void v9fs_session_begin_cancel(struct v9fs_session_info *v9ses);
146extern struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
147			unsigned int flags);
148extern int v9fs_vfs_unlink(struct inode *i, struct dentry *d);
149extern int v9fs_vfs_rmdir(struct inode *i, struct dentry *d);
150extern int v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
151			struct inode *new_dir, struct dentry *new_dentry);
152extern void v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd,
153			void *p);
154extern struct inode *v9fs_inode_from_fid(struct v9fs_session_info *v9ses,
155					 struct p9_fid *fid,
156					 struct super_block *sb, int new);
157extern const struct inode_operations v9fs_dir_inode_operations_dotl;
158extern const struct inode_operations v9fs_file_inode_operations_dotl;
159extern const struct inode_operations v9fs_symlink_inode_operations_dotl;
160extern struct inode *v9fs_inode_from_fid_dotl(struct v9fs_session_info *v9ses,
161					      struct p9_fid *fid,
162					      struct super_block *sb, int new);
163
164/* other default globals */
165#define V9FS_PORT	564
166#define V9FS_DEFUSER	"nobody"
167#define V9FS_DEFANAME	""
168#define V9FS_DEFUID	KUIDT_INIT(-2)
169#define V9FS_DEFGID	KGIDT_INIT(-2)
170
171static inline struct v9fs_session_info *v9fs_inode2v9ses(struct inode *inode)
172{
173	return (inode->i_sb->s_fs_info);
174}
175
176static inline struct v9fs_session_info *v9fs_dentry2v9ses(struct dentry *dentry)
177{
178	return dentry->d_sb->s_fs_info;
179}
180
181static inline int v9fs_proto_dotu(struct v9fs_session_info *v9ses)
182{
183	return v9ses->flags & V9FS_PROTO_2000U;
184}
185
186static inline int v9fs_proto_dotl(struct v9fs_session_info *v9ses)
187{
188	return v9ses->flags & V9FS_PROTO_2000L;
189}
190
191/**
192 * v9fs_get_inode_from_fid - Helper routine to populate an inode by
193 * issuing a attribute request
194 * @v9ses: session information
195 * @fid: fid to issue attribute request for
196 * @sb: superblock on which to create inode
197 *
198 */
199static inline struct inode *
200v9fs_get_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
201			struct super_block *sb)
202{
203	if (v9fs_proto_dotl(v9ses))
204		return v9fs_inode_from_fid_dotl(v9ses, fid, sb, 0);
205	else
206		return v9fs_inode_from_fid(v9ses, fid, sb, 0);
207}
208
209/**
210 * v9fs_get_new_inode_from_fid - Helper routine to populate an inode by
211 * issuing a attribute request
212 * @v9ses: session information
213 * @fid: fid to issue attribute request for
214 * @sb: superblock on which to create inode
215 *
216 */
217static inline struct inode *
218v9fs_get_new_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
219			    struct super_block *sb)
220{
221	if (v9fs_proto_dotl(v9ses))
222		return v9fs_inode_from_fid_dotl(v9ses, fid, sb, 1);
223	else
224		return v9fs_inode_from_fid(v9ses, fid, sb, 1);
225}
226
227#endif
228