kernel/drivers/target/iscsi/iscsi_target_transport.c

   1 #include <linux/spinlock.h>
   2 #include <linux/list.h>
   3 #include <target/iscsi/iscsi_transport.h>
   4
   5 static LIST_HEAD(g_transport_list);
   6 static DEFINE_MUTEX(transport_mutex);
   7
   8 struct iscsit_transport *iscsit_get_transport(int type)
   9 {
  10         struct iscsit_transport *t;
  11
  12         mutex_lock(&transport_mutex);
  13         list_for_each_entry(t, &g_transport_list, t_node) {
  14                 if (t->transport_type == type) {
  15                         if (t->owner && !try_module_get(t->owner)) {
  16                                 t = NULL;
  17                         }
  18                         mutex_unlock(&transport_mutex);
  19                         return t;
  20                 }
  21         }
  22         mutex_unlock(&transport_mutex);
  23
  24         return NULL;
  25 }
  26
  27 void iscsit_put_transport(struct iscsit_transport *t)
  28 {
  29         module_put(t->owner);
  30 }
  31
  32 int iscsit_register_transport(struct iscsit_transport *t)
  33 {
  34         INIT_LIST_HEAD(&t->t_node);
  35
  36         mutex_lock(&transport_mutex);
  37         list_add_tail(&t->t_node, &g_transport_list);
  38         mutex_unlock(&transport_mutex);
  39
  40         pr_debug("Registered iSCSI transport: %s\n", t->name);
  41
  42         return 0;
  43 }
  44 EXPORT_SYMBOL(iscsit_register_transport);
  45
  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);