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
_p9_debug(enum p9_debug_flags level,const char * func,const char * fmt,...)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 */
v9fs_register_trans(struct p9_trans_module * m)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 */
v9fs_unregister_trans(struct p9_trans_module * m)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 */
v9fs_get_trans_by_name(char * s)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
v9fs_get_default_trans(void)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 */
v9fs_put_trans(struct p9_trans_module * m)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 */
init_p9(void)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
exit_p9(void)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");
202