72029fe85d
9p trans modules aren't refcounted nor were they unregistered properly. Fix it. * Add 9p_trans_module->owner and reference the module on each trans instance creation and put it on destruction. * Protect v9fs_trans_list with a spinlock. This isn't strictly necessary as the list is manipulated only during module loading / unloading but it's a good idea to make the API safe. * Unregister trans modules when the corresponding module is being unloaded. * While at it, kill unnecessary EXPORT_SYMBOL on p9_trans_fd_init(). Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
173 lines
3.8 KiB
C
173 lines
3.8 KiB
C
/*
|
|
* net/9p/9p.c
|
|
*
|
|
* 9P entry point
|
|
*
|
|
* Copyright (C) 2007 by Latchesar Ionkov <lucho@ionkov.net>
|
|
* Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
|
|
* Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2
|
|
* as published by the Free Software Foundation.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to:
|
|
* Free Software Foundation
|
|
* 51 Franklin Street, Fifth Floor
|
|
* Boston, MA 02111-1301 USA
|
|
*
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/moduleparam.h>
|
|
#include <net/9p/9p.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/parser.h>
|
|
#include <net/9p/transport.h>
|
|
#include <linux/list.h>
|
|
#include <linux/spinlock.h>
|
|
|
|
#ifdef CONFIG_NET_9P_DEBUG
|
|
unsigned int p9_debug_level = 0; /* feature-rific global debug level */
|
|
EXPORT_SYMBOL(p9_debug_level);
|
|
module_param_named(debug, p9_debug_level, uint, 0);
|
|
MODULE_PARM_DESC(debug, "9P debugging level");
|
|
#endif
|
|
|
|
/*
|
|
* Dynamic Transport Registration Routines
|
|
*
|
|
*/
|
|
|
|
static DEFINE_SPINLOCK(v9fs_trans_lock);
|
|
static LIST_HEAD(v9fs_trans_list);
|
|
|
|
/**
|
|
* v9fs_register_trans - register a new transport with 9p
|
|
* @m: structure describing the transport module and entry points
|
|
*
|
|
*/
|
|
void v9fs_register_trans(struct p9_trans_module *m)
|
|
{
|
|
spin_lock(&v9fs_trans_lock);
|
|
list_add_tail(&m->list, &v9fs_trans_list);
|
|
spin_unlock(&v9fs_trans_lock);
|
|
}
|
|
EXPORT_SYMBOL(v9fs_register_trans);
|
|
|
|
/**
|
|
* v9fs_unregister_trans - unregister a 9p transport
|
|
* @m: the transport to remove
|
|
*
|
|
*/
|
|
void v9fs_unregister_trans(struct p9_trans_module *m)
|
|
{
|
|
spin_lock(&v9fs_trans_lock);
|
|
list_del_init(&m->list);
|
|
spin_unlock(&v9fs_trans_lock);
|
|
}
|
|
EXPORT_SYMBOL(v9fs_unregister_trans);
|
|
|
|
/**
|
|
* v9fs_get_trans_by_name - get transport with the matching name
|
|
* @name: string identifying transport
|
|
*
|
|
*/
|
|
struct p9_trans_module *v9fs_get_trans_by_name(const substring_t *name)
|
|
{
|
|
struct p9_trans_module *t, *found = NULL;
|
|
|
|
spin_lock(&v9fs_trans_lock);
|
|
|
|
list_for_each_entry(t, &v9fs_trans_list, list)
|
|
if (strncmp(t->name, name->from, name->to-name->from) == 0 &&
|
|
try_module_get(t->owner)) {
|
|
found = t;
|
|
break;
|
|
}
|
|
|
|
spin_unlock(&v9fs_trans_lock);
|
|
return found;
|
|
}
|
|
EXPORT_SYMBOL(v9fs_get_trans_by_name);
|
|
|
|
/**
|
|
* v9fs_get_default_trans - get the default transport
|
|
*
|
|
*/
|
|
|
|
struct p9_trans_module *v9fs_get_default_trans(void)
|
|
{
|
|
struct p9_trans_module *t, *found = NULL;
|
|
|
|
spin_lock(&v9fs_trans_lock);
|
|
|
|
list_for_each_entry(t, &v9fs_trans_list, list)
|
|
if (t->def && try_module_get(t->owner)) {
|
|
found = t;
|
|
break;
|
|
}
|
|
|
|
if (!found)
|
|
list_for_each_entry(t, &v9fs_trans_list, list)
|
|
if (try_module_get(t->owner)) {
|
|
found = t;
|
|
break;
|
|
}
|
|
|
|
spin_unlock(&v9fs_trans_lock);
|
|
return found;
|
|
}
|
|
EXPORT_SYMBOL(v9fs_get_default_trans);
|
|
|
|
/**
|
|
* v9fs_put_trans - put trans
|
|
* @m: transport to put
|
|
*
|
|
*/
|
|
void v9fs_put_trans(struct p9_trans_module *m)
|
|
{
|
|
if (m)
|
|
module_put(m->owner);
|
|
}
|
|
|
|
/**
|
|
* v9fs_init - Initialize module
|
|
*
|
|
*/
|
|
static int __init init_p9(void)
|
|
{
|
|
int ret = 0;
|
|
|
|
p9_error_init();
|
|
printk(KERN_INFO "Installing 9P2000 support\n");
|
|
p9_trans_fd_init();
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* v9fs_init - shutdown module
|
|
*
|
|
*/
|
|
|
|
static void __exit exit_p9(void)
|
|
{
|
|
printk(KERN_INFO "Unloading 9P2000 support\n");
|
|
|
|
p9_trans_fd_exit();
|
|
}
|
|
|
|
module_init(init_p9)
|
|
module_exit(exit_p9)
|
|
|
|
MODULE_AUTHOR("Latchesar Ionkov <lucho@ionkov.net>");
|
|
MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
|
|
MODULE_AUTHOR("Ron Minnich <rminnich@lanl.gov>");
|
|
MODULE_LICENSE("GPL");
|