iscsi-target: Initial traditional TCP conversion to iscsit_transport

This patch performs the initial conversion of existing traditional iscsi
to use iscsit_transport API callers.  This includes:

- iscsi-np cleanups for iscsit_transport_type
- Add iscsi-np transport calls w/ ->iscsit_setup_up() and ->iscsit_free_np()
- Convert login thread process context to use ->iscsit_accept_np() for
  connections with pre-allocated struct iscsi_conn
- Convert existing socket accept code to iscsit_accept_np()
- Convert login RX/TX callers to use ->iscsit_get_login_rx() and
  ->iscsit_put_login_tx() to exchange request/response PDUs
- Convert existing socket login RX/TX calls into iscsit_get_login_rx()
  and iscsit_put_login_tx()
- Change iscsit_close_connection() to invoke ->iscsit_free_conn() +
  iscsit_put_transport() calls.
- Add iscsit_register_transport() + iscsit_unregister_transport() calls
  to module init/exit

v4 changes:

- Add missing iscsit_put_transport() call in iscsi_target_setup_login_socket()
  failure case

v2 changes:

- Update module init/exit to use register_transport() + unregister_transport()

Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

1 files changed, 28 insertions, 7 deletions

diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c
index 7ea246a07731..8203bf3de848 100644
--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -49,6 +49,8 @@
 #include "iscsi_target_device.h"
 #include "iscsi_target_stat.h"
 
+#include <target/iscsi/iscsi_transport.h>
+
 static LIST_HEAD(g_tiqn_list);
 static LIST_HEAD(g_np_list);
 static DEFINE_SPINLOCK(tiqn_lock);
@@ -401,8 +403,7 @@ struct iscsi_np *iscsit_add_np(
         spin_unlock_bh(&np_lock);
 
         pr_debug("CORE[0] - Added Network Portal: %s:%hu on %s\n",
-                np->np_ip, np->np_port, (np->np_network_transport == ISCSI_TCP) ?
-                "TCP" : "SCTP");
+                np->np_ip, np->np_port, np->np_transport->name);
 
         return np;
 }
@@ -441,11 +442,10 @@ int iscsit_reset_np_thread(
         return 0;
 }
 
-static int iscsit_del_np_comm(struct iscsi_np *np)
+static void iscsit_free_np(struct iscsi_np *np)
 {
         if (np->np_socket)
                 sock_release(np->np_socket);
-        return 0;
 }
 
 int iscsit_del_np(struct iscsi_np *np)
@@ -467,20 +467,32 @@ int iscsit_del_np(struct iscsi_np *np)
                 send_sig(SIGINT, np->np_thread, 1);
                 kthread_stop(np->np_thread);
         }
-        iscsit_del_np_comm(np);
+
+        np->np_transport->iscsit_free_np(np);
 
         spin_lock_bh(&np_lock);
         list_del(&np->np_list);
         spin_unlock_bh(&np_lock);
 
         pr_debug("CORE[0] - Removed Network Portal: %s:%hu on %s\n",
-                np->np_ip, np->np_port, (np->np_network_transport == ISCSI_TCP) ?
-                "TCP" : "SCTP");
+                np->np_ip, np->np_port, np->np_transport->name);
 
+        iscsit_put_transport(np->np_transport);
         kfree(np);
         return 0;
 }
 
+static struct iscsit_transport iscsi_target_transport = {
+        .name                   = "iSCSI/TCP",
+        .transport_type         = ISCSI_TCP,
+        .owner                  = NULL,
+        .iscsit_setup_np        = iscsit_setup_np,
+        .iscsit_accept_np       = iscsit_accept_np,
+        .iscsit_free_np         = iscsit_free_np,
+        .iscsit_get_login_rx    = iscsit_get_login_rx,
+        .iscsit_put_login_tx    = iscsit_put_login_tx,
+};
+
 static int __init iscsi_target_init_module(void)
 {
         int ret = 0;
@@ -557,6 +569,8 @@ static int __init iscsi_target_init_module(void)
                 goto ooo_out;
         }
 
+        iscsit_register_transport(&iscsi_target_transport);
+
         if (iscsit_load_discovery_tpg() < 0)
                 goto r2t_out;
 
@@ -587,6 +601,7 @@ static void __exit iscsi_target_cleanup_module(void)
         iscsi_deallocate_thread_sets();
         iscsi_thread_set_free();
         iscsit_release_discovery_tpg();
+        iscsit_unregister_transport(&iscsi_target_transport);
         kmem_cache_destroy(lio_cmd_cache);
         kmem_cache_destroy(lio_qr_cache);
         kmem_cache_destroy(lio_dr_cache);
@@ -4053,6 +4068,12 @@ int iscsit_close_connection(
 
         if (conn->sock)
                 sock_release(conn->sock);
+
+        if (conn->conn_transport->iscsit_free_conn)
+                conn->conn_transport->iscsit_free_conn(conn);
+
+        iscsit_put_transport(conn->conn_transport);
+
         conn->thread_set = NULL;
 
         pr_debug("Moving to TARG_CONN_STATE_FREE.\n");