6ab36aea77275ef342b88f8e66e0e5c294086fd0
[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 #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
42 unsigned int p9_debug_level = 0;        /* feature-rific global debug level  */
43 EXPORT_SYMBOL(p9_debug_level);
44 module_param_named(debug, p9_debug_level, uint, 0);
45 MODULE_PARM_DESC(debug, "9P debugging level");
46
47 void _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 }
68 EXPORT_SYMBOL(_p9_debug);
69 #endif
70
71 /*
72  * Dynamic Transport Registration Routines
73  *
74  */
75
76 static DEFINE_SPINLOCK(v9fs_trans_lock);
77 static 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  */
84 void 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 }
90 EXPORT_SYMBOL(v9fs_register_trans);
91
92 /**
93  * v9fs_unregister_trans - unregister a 9p transport
94  * @m: the transport to remove
95  *
96  */
97 void 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 }
103 EXPORT_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  */
110 struct 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 }
126 EXPORT_SYMBOL(v9fs_get_trans_by_name);
127
128 /**
129  * v9fs_get_default_trans - get the default transport
130  *
131  */
132
133 struct 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 }
155 EXPORT_SYMBOL(v9fs_get_default_trans);
156
157 /**
158  * v9fs_put_trans - put trans
159  * @m: transport to put
160  *
161  */
162 void 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  */
172 static 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
188 static void __exit exit_p9(void)
189 {
190         pr_info("Unloading 9P2000 support\n");
191
192         p9_trans_fd_exit();
193 }
194
195 module_init(init_p9)
196 module_exit(exit_p9)
197
198 MODULE_AUTHOR("Latchesar Ionkov <lucho@ionkov.net>");
199 MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
200 MODULE_AUTHOR("Ron Minnich <rminnich@lanl.gov>");
201 MODULE_LICENSE("GPL");