ipv4: fix redirect handling
[linux-2.6.git] / net / 9p / mod.c
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
38 unsigned int p9_debug_level = 0;        /* feature-rific global debug level  */
39 EXPORT_SYMBOL(p9_debug_level);
40 module_param_named(debug, p9_debug_level, uint, 0);
41 MODULE_PARM_DESC(debug, "9P debugging level");
42 #endif
43
44 /*
45  * Dynamic Transport Registration Routines
46  *
47  */
48
49 static DEFINE_SPINLOCK(v9fs_trans_lock);
50 static 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  */
57 void 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 }
63 EXPORT_SYMBOL(v9fs_register_trans);
64
65 /**
66  * v9fs_unregister_trans - unregister a 9p transport
67  * @m: the transport to remove
68  *
69  */
70 void 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 }
76 EXPORT_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  */
83 struct p9_trans_module *v9fs_get_trans_by_name(char *s)
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 (strcmp(t->name, s) == 0 &&
91                     try_module_get(t->owner)) {
92                         found = t;
93                         break;
94                 }
95
96         spin_unlock(&v9fs_trans_lock);
97         return found;
98 }
99 EXPORT_SYMBOL(v9fs_get_trans_by_name);
100
101 /**
102  * v9fs_get_default_trans - get the default transport
103  *
104  */
105
106 struct 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 }
128 EXPORT_SYMBOL(v9fs_get_default_trans);
129
130 /**
131  * v9fs_put_trans - put trans
132  * @m: transport to put
133  *
134  */
135 void v9fs_put_trans(struct p9_trans_module *m)
136 {
137         if (m)
138                 module_put(m->owner);
139 }
140
141 /**
142  * init_p9 - Initialize module
143  *
144  */
145 static 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  * exit_p9 - shutdown module
158  *
159  */
160
161 static void __exit exit_p9(void)
162 {
163         printk(KERN_INFO "Unloading 9P2000 support\n");
164
165         p9_trans_fd_exit();
166 }
167
168 module_init(init_p9)
169 module_exit(exit_p9)
170
171 MODULE_AUTHOR("Latchesar Ionkov <lucho@ionkov.net>");
172 MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
173 MODULE_AUTHOR("Ron Minnich <rminnich@lanl.gov>");
174 MODULE_LICENSE("GPL");