1/*
2 *  net/9p/9p.c
3 *
4 *  9P entry point
5 *
6 *  Copyright (C) 2007 by Latchesar Ionkov <lucho@ionkov.net>
7 *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
8 *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
9 *
10 *  This program is free software; you can redistribute it and/or modify
11 *  it under the terms of the GNU General Public License version 2
12 *  as published by the Free Software Foundation.
13 *
14 *  This program is distributed in the hope that it will be useful,
15 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
16 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17 *  GNU General Public License for more details.
18 *
19 *  You should have received a copy of the GNU General Public License
20 *  along with this program; if not, write to:
21 *  Free Software Foundation
22 *  51 Franklin Street, Fifth Floor
23 *  Boston, MA  02111-1301  USA
24 *
25 */
26
27#include <linux/module.h>
28#include <linux/moduleparam.h>
29#include <net/9p/9p.h>
30#include <linux/fs.h>
31#include <linux/parser.h>
32#include <net/9p/client.h>
33#include <net/9p/transport.h>
34#include <linux/list.h>
35#include <linux/spinlock.h>
36
37#ifdef CONFIG_NET_9P_DEBUG
38unsigned int p9_debug_level = 0;	/* feature-rific global debug level  */
39EXPORT_SYMBOL(p9_debug_level);
40module_param_named(debug, p9_debug_level, uint, 0);
41MODULE_PARM_DESC(debug, "9P debugging level");
42#endif
43
44/*
45 * Dynamic Transport Registration Routines
46 *
47 */
48
49static DEFINE_SPINLOCK(v9fs_trans_lock);
50static LIST_HEAD(v9fs_trans_list);
51
52/**
53 * v9fs_register_trans - register a new transport with 9p
54 * @m: structure describing the transport module and entry points
55 *
56 */
57void v9fs_register_trans(struct p9_trans_module *m)
58{
59	spin_lock(&v9fs_trans_lock);
60	list_add_tail(&m->list, &v9fs_trans_list);
61	spin_unlock(&v9fs_trans_lock);
62}
63EXPORT_SYMBOL(v9fs_register_trans);
64
65/**
66 * v9fs_unregister_trans - unregister a 9p transport
67 * @m: the transport to remove
68 *
69 */
70void v9fs_unregister_trans(struct p9_trans_module *m)
71{
72	spin_lock(&v9fs_trans_lock);
73	list_del_init(&m->list);
74	spin_unlock(&v9fs_trans_lock);
75}
76EXPORT_SYMBOL(v9fs_unregister_trans);
77
78/**
79 * v9fs_get_trans_by_name - get transport with the matching name
80 * @name: string identifying transport
81 *
82 */
83struct p9_trans_module *v9fs_get_trans_by_name(const substring_t *name)
84{
85	struct p9_trans_module *t, *found = NULL;
86
87	spin_lock(&v9fs_trans_lock);
88
89	list_for_each_entry(t, &v9fs_trans_list, list)
90		if (strncmp(t->name, name->from, name->to-name->from) == 0 &&
91		    try_module_get(t->owner)) {
92			found = t;
93			break;
94		}
95
96	spin_unlock(&v9fs_trans_lock);
97	return found;
98}
99EXPORT_SYMBOL(v9fs_get_trans_by_name);
100
101/**
102 * v9fs_get_default_trans - get the default transport
103 *
104 */
105
106struct p9_trans_module *v9fs_get_default_trans(void)
107{
108	struct p9_trans_module *t, *found = NULL;
109
110	spin_lock(&v9fs_trans_lock);
111
112	list_for_each_entry(t, &v9fs_trans_list, list)
113		if (t->def && try_module_get(t->owner)) {
114			found = t;
115			break;
116		}
117
118	if (!found)
119		list_for_each_entry(t, &v9fs_trans_list, list)
120			if (try_module_get(t->owner)) {
121				found = t;
122				break;
123			}
124
125	spin_unlock(&v9fs_trans_lock);
126	return found;
127}
128EXPORT_SYMBOL(v9fs_get_default_trans);
129
130/**
131 * v9fs_put_trans - put trans
132 * @m: transport to put
133 *
134 */
135void v9fs_put_trans(struct p9_trans_module *m)
136{
137	if (m)
138		module_put(m->owner);
139}
140
141/**
142 * v9fs_init - Initialize module
143 *
144 */
145static int __init init_p9(void)
146{
147	int ret = 0;
148
149	p9_error_init();
150	printk(KERN_INFO "Installing 9P2000 support\n");
151	p9_trans_fd_init();
152
153	return ret;
154}
155
156/**
157 * v9fs_init - shutdown module
158 *
159 */
160
161static void __exit exit_p9(void)
162{
163	printk(KERN_INFO "Unloading 9P2000 support\n");
164
165	p9_trans_fd_exit();
166}
167
168module_init(init_p9)
169module_exit(exit_p9)
170
171MODULE_AUTHOR("Latchesar Ionkov <lucho@ionkov.net>");
172MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
173MODULE_AUTHOR("Ron Minnich <rminnich@lanl.gov>");
174MODULE_LICENSE("GPL");
175