// SPDX-License-Identifier: GPL-2.0-only/* *  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> */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/module.h>#include <linux/kmod.h>#include <linux/errno.h>#include <linux/sched.h>#include <linux/moduleparam.h>#include <net/9p/9p.h>#include <linux/fs.h>#include <net/9p/client.h>#include <net/9p/transport.h>#include <linux/list.h>#include <linux/spinlock.h> #ifdef CONFIG_NET_9P_DEBUGunsigned int p9_debug_level;	/* 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"); void _p9_debug(enum p9_debug_flags level, const char *func,	       const char *fmt, ...){	struct va_format vaf;	va_list args; 	if ((p9_debug_level & level) != level)		return; 	va_start(args, fmt); 	vaf.fmt = fmt;	vaf.va = &args; 	if (level == P9_DEBUG_9P)		pr_notice("(%8.8d) %pV", task_pid_nr(current), &vaf);	else		pr_notice("-- %s (%d): %pV", func, task_pid_nr(current), &vaf); 	va_end(args);}EXPORT_SYMBOL(_p9_debug);#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); static struct p9_trans_module *_p9_get_trans_by_name(const char *s){	struct p9_trans_module *t, *found = NULL; 	spin_lock(&v9fs_trans_lock); 	list_for_each_entry(t, &v9fs_trans_list, list)		if (strcmp(t->name, s) == 0 &&		    try_module_get(t->owner)) {			found = t;			break;		} 	spin_unlock(&v9fs_trans_lock); 	return found;} /** * v9fs_get_trans_by_name - get transport with the matching name * @s: string identifying transport * */struct p9_trans_module *v9fs_get_trans_by_name(const char *s){	struct p9_trans_module *found = NULL; 	found = _p9_get_trans_by_name(s); #ifdef CONFIG_MODULES	if (!found) {		request_module("9p-%s", s);		found = _p9_get_trans_by_name(s);	}#endif 	return found;}EXPORT_SYMBOL(v9fs_get_trans_by_name); static const char * const v9fs_default_transports[] = {	"virtio", "tcp", "fd", "unix", "xen", "rdma",}; /** * v9fs_get_default_trans - get the default transport * */ struct p9_trans_module *v9fs_get_default_trans(void){	struct p9_trans_module *t, *found = NULL;	int i; 	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); 	for (i = 0; !found && i < ARRAY_SIZE(v9fs_default_transports); i++)		found = v9fs_get_trans_by_name(v9fs_default_transports[i]); 	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);}EXPORT_SYMBOL(v9fs_put_trans); /** * init_p9 - Initialize module * */static int __init init_p9(void){	int ret; 	ret = p9_client_init();	if (ret)		return ret; 	p9_error_init();	pr_info("Installing 9P2000 support\n"); 	return ret;} /** * exit_p9 - shutdown module * */ static void __exit exit_p9(void){	pr_info("Unloading 9P2000 support\n"); 	p9_client_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");MODULE_DESCRIPTION("Plan 9 Resource Sharing Support (9P2000)");