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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
28
29#include <linux/module.h>
30#include <linux/errno.h>
31#include <linux/sched.h>
32#include <linux/moduleparam.h>
33#include <net/9p/9p.h>
34#include <linux/fs.h>
35#include <linux/parser.h>
36#include <net/9p/client.h>
37#include <net/9p/transport.h>
38#include <linux/list.h>
39#include <linux/spinlock.h>
40
41#ifdef CONFIG_NET_9P_DEBUG
42unsigned int p9_debug_level = 0;	/* feature-rific global debug level  */
43EXPORT_SYMBOL(p9_debug_level);
44module_param_named(debug, p9_debug_level, uint, 0);
45MODULE_PARM_DESC(debug, "9P debugging level");
46
47void _p9_debug(enum p9_debug_flags level, const char *func,
48		const char *fmt, ...)
49{
50	struct va_format vaf;
51	va_list args;
52
53	if ((p9_debug_level & level) != level)
54		return;
55
56	va_start(args, fmt);
57
58	vaf.fmt = fmt;
59	vaf.va = &args;
60
61	if (level == P9_DEBUG_9P)
62		pr_notice("(%8.8d) %pV", task_pid_nr(current), &vaf);
63	else
64		pr_notice("-- %s (%d): %pV", func, task_pid_nr(current), &vaf);
65
66	va_end(args);
67}
68EXPORT_SYMBOL(_p9_debug);
69#endif
70
71/*
72 * Dynamic Transport Registration Routines
73 *
74 */
75
76static DEFINE_SPINLOCK(v9fs_trans_lock);
77static LIST_HEAD(v9fs_trans_list);
78
79/**
80 * v9fs_register_trans - register a new transport with 9p
81 * @m: structure describing the transport module and entry points
82 *
83 */
84void v9fs_register_trans(struct p9_trans_module *m)
85{
86	spin_lock(&v9fs_trans_lock);
87	list_add_tail(&m->list, &v9fs_trans_list);
88	spin_unlock(&v9fs_trans_lock);
89}
90EXPORT_SYMBOL(v9fs_register_trans);
91
92/**
93 * v9fs_unregister_trans - unregister a 9p transport
94 * @m: the transport to remove
95 *
96 */
97void v9fs_unregister_trans(struct p9_trans_module *m)
98{
99	spin_lock(&v9fs_trans_lock);
100	list_del_init(&m->list);
101	spin_unlock(&v9fs_trans_lock);
102}
103EXPORT_SYMBOL(v9fs_unregister_trans);
104
105/**
106 * v9fs_get_trans_by_name - get transport with the matching name
107 * @name: string identifying transport
108 *
109 */
110struct p9_trans_module *v9fs_get_trans_by_name(char *s)
111{
112	struct p9_trans_module *t, *found = NULL;
113
114	spin_lock(&v9fs_trans_lock);
115
116	list_for_each_entry(t, &v9fs_trans_list, list)
117		if (strcmp(t->name, s) == 0 &&
118		    try_module_get(t->owner)) {
119			found = t;
120			break;
121		}
122
123	spin_unlock(&v9fs_trans_lock);
124	return found;
125}
126EXPORT_SYMBOL(v9fs_get_trans_by_name);
127
128/**
129 * v9fs_get_default_trans - get the default transport
130 *
131 */
132
133struct p9_trans_module *v9fs_get_default_trans(void)
134{
135	struct p9_trans_module *t, *found = NULL;
136
137	spin_lock(&v9fs_trans_lock);
138
139	list_for_each_entry(t, &v9fs_trans_list, list)
140		if (t->def && try_module_get(t->owner)) {
141			found = t;
142			break;
143		}
144
145	if (!found)
146		list_for_each_entry(t, &v9fs_trans_list, list)
147			if (try_module_get(t->owner)) {
148				found = t;
149				break;
150			}
151
152	spin_unlock(&v9fs_trans_lock);
153	return found;
154}
155EXPORT_SYMBOL(v9fs_get_default_trans);
156
157/**
158 * v9fs_put_trans - put trans
159 * @m: transport to put
160 *
161 */
162void v9fs_put_trans(struct p9_trans_module *m)
163{
164	if (m)
165		module_put(m->owner);
166}
167
168/**
169 * init_p9 - Initialize module
170 *
171 */
172static int __init init_p9(void)
173{
174	int ret = 0;
175
176	p9_error_init();
177	pr_info("Installing 9P2000 support\n");
178	p9_trans_fd_init();
179
180	return ret;
181}
182
183/**
184 * exit_p9 - shutdown module
185 *
186 */
187
188static void __exit exit_p9(void)
189{
190	pr_info("Unloading 9P2000 support\n");
191
192	p9_trans_fd_exit();
193}
194
195module_init(init_p9)
196module_exit(exit_p9)
197
198MODULE_AUTHOR("Latchesar Ionkov <lucho@ionkov.net>");
199MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
200MODULE_AUTHOR("Ron Minnich <rminnich@lanl.gov>");
201MODULE_LICENSE("GPL");
202