xref: /linux/drivers/target/iscsi/iscsi_target_transport.c (revision 4b4193256c8d3bc3a5397b5cd9494c2ad386317d) 
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/spinlock.h>
3 #include <linux/list.h>
4 #include <linux/module.h>
5 #include <target/iscsi/iscsi_transport.h>
6 
7 static LIST_HEAD(g_transport_list);
8 static DEFINE_MUTEX(transport_mutex);
9 
iscsit_get_transport(int type)10 struct iscsit_transport *iscsit_get_transport(int type)
11 {
12 	struct iscsit_transport *t;
13 
14 	mutex_lock(&transport_mutex);
15 	list_for_each_entry(t, &g_transport_list, t_node) {
16 		if (t->transport_type == type) {
17 			if (t->owner && !try_module_get(t->owner)) {
18 				t = NULL;
19 			}
20 			mutex_unlock(&transport_mutex);
21 			return t;
22 		}
23 	}
24 	mutex_unlock(&transport_mutex);
25 
26 	return NULL;
27 }
28 
iscsit_put_transport(struct iscsit_transport * t)29 void iscsit_put_transport(struct iscsit_transport *t)
30 {
31 	module_put(t->owner);
32 }
33 
iscsit_register_transport(struct iscsit_transport * t)34 void iscsit_register_transport(struct iscsit_transport *t)
35 {
36 	INIT_LIST_HEAD(&t->t_node);
37 
38 	mutex_lock(&transport_mutex);
39 	list_add_tail(&t->t_node, &g_transport_list);
40 	mutex_unlock(&transport_mutex);
41 
42 	pr_debug("Registered iSCSI transport: %s\n", t->name);
43 }
44 EXPORT_SYMBOL(iscsit_register_transport);
45 
iscsit_unregister_transport(struct iscsit_transport * t)46 void iscsit_unregister_transport(struct iscsit_transport *t)
47 {
48 	mutex_lock(&transport_mutex);
49 	list_del(&t->t_node);
50 	mutex_unlock(&transport_mutex);
51 
52 	pr_debug("Unregistered iSCSI transport: %s\n", t->name);
53 }
54 EXPORT_SYMBOL(iscsit_unregister_transport);
55