target: make ->shutdown_session optional

Turns out the template and thus many drivers got the return value wrong:
0 means the fabrics driver needs to put a session reference, which no
driver except for the iSCSI target drivers did. Fortunately none of these
drivers supports explicit Node ACLs, so the bug was harmless.

Even without that only qla2xxx and iscsi every did real work in
shutdown_session, so get rid of the boilerplate code in all other
drivers.

Signed-off-by: Christoph Hellwig <[e-mail]>
Signed-off-by: Nicholas Bellinger <[e-mail]>

Documentation/target/tcm_mod_builder.py

···
 	buf += "	.tpg_check_prod_mode_write_protect = " + fabric_mod_name + "_check_false,\n"
 	buf += "	.tpg_get_inst_index		= " + fabric_mod_name + "_tpg_get_inst_index,\n"
 	buf += "	.release_cmd			= " + fabric_mod_name + "_release_cmd,\n"
-	buf += "	.shutdown_session		= " + fabric_mod_name + "_shutdown_session,\n"
 	buf += "	.close_session			= " + fabric_mod_name + "_close_session,\n"
 	buf += "	.sess_get_index			= " + fabric_mod_name + "_sess_get_index,\n"
 	buf += "	.sess_get_initiator_sid		= NULL,\n"
···
 			buf += "	return;\n"
 			buf += "}\n\n"
 			bufi += "void " + fabric_mod_name + "_release_cmd(struct se_cmd *);\n"
-
-		if re.search('shutdown_session\)\(', fo):
-			buf += "int " + fabric_mod_name + "_shutdown_session(struct se_session *se_sess)\n"
-			buf += "{\n"
-			buf += "	return 0;\n"
-			buf += "}\n\n"
-			bufi += "int " + fabric_mod_name + "_shutdown_session(struct se_session *);\n"
 
 		if re.search('close_session\)\(', fo):
 			buf += "void " + fabric_mod_name + "_close_session(struct se_session *se_sess)\n"

drivers/infiniband/ulp/srpt/ib_srpt.c

···
 	}
 }
 
-/**
- * srpt_shutdown_session() - Whether or not a session may be shut down.
- */
-static int srpt_shutdown_session(struct se_session *se_sess)
-{
-	return 1;
-}
-
 static void srpt_free_ch(struct kref *kref)
 {
 	struct srpt_rdma_ch *ch = container_of(kref, struct srpt_rdma_ch, kref);
···
 	.tpg_get_inst_index		= srpt_tpg_get_inst_index,
 	.release_cmd			= srpt_release_cmd,
 	.check_stop_free		= srpt_check_stop_free,
-	.shutdown_session		= srpt_shutdown_session,
 	.close_session			= srpt_close_session,
 	.sess_get_index			= srpt_sess_get_index,
 	.sess_get_initiator_sid		= NULL,

drivers/target/loopback/tcm_loop.c

···
 	return tl_cmd->sc_cmd_state;
 }
 
-static int tcm_loop_shutdown_session(struct se_session *se_sess)
-{
-	return 0;
-}
-
 static void tcm_loop_close_session(struct se_session *se_sess)
 {
 	return;
···
 	.tpg_get_inst_index		= tcm_loop_get_inst_index,
 	.check_stop_free		= tcm_loop_check_stop_free,
 	.release_cmd			= tcm_loop_release_cmd,
-	.shutdown_session		= tcm_loop_shutdown_session,
 	.close_session			= tcm_loop_close_session,
 	.sess_get_index			= tcm_loop_sess_get_index,
 	.write_pending			= tcm_loop_write_pending,

drivers/target/sbp/sbp_target.c

···
 	sbp_free_request(req);
 }
 
-static int sbp_shutdown_session(struct se_session *se_sess)
-{
-	return 0;
-}
-
 static void sbp_close_session(struct se_session *se_sess)
 {
 	return;
···
 	.tpg_check_prod_mode_write_protect = sbp_check_false,
 	.tpg_get_inst_index		= sbp_tpg_get_inst_index,
 	.release_cmd			= sbp_release_cmd,
-	.shutdown_session		= sbp_shutdown_session,
 	.close_session			= sbp_close_session,
 	.sess_get_index			= sbp_sess_get_index,
 	.write_pending			= sbp_write_pending,

drivers/target/target_core_configfs.c

···
 		pr_err("Missing tfo->release_cmd()\n");
 		return -EINVAL;
 	}
-	if (!tfo->shutdown_session) {
-		pr_err("Missing tfo->shutdown_session()\n");
-		return -EINVAL;
-	}
 	if (!tfo->close_session) {
 		pr_err("Missing tfo->close_session()\n");
 		return -EINVAL;

drivers/target/target_core_tpg.c

···
 		list_del_init(&sess->sess_acl_list);
 
 		spin_unlock_irqrestore(&acl->nacl_sess_lock, flags);
-		ret = acl->se_tpg->se_tpg_tfo->shutdown_session(sess);
+		if (acl->se_tpg->se_tpg_tfo->shutdown_session)
+			ret = acl->se_tpg->se_tpg_tfo->shutdown_session(sess);
+		else
+			ret = 1;
 		target_put_session(sess);
 		if (ret)
 			target_put_session(sess);

drivers/target/tcm_fc/tcm_fc.h

···
  * Session ops.
  */
 void ft_sess_put(struct ft_sess *);
-int ft_sess_shutdown(struct se_session *);
 void ft_sess_close(struct se_session *);
 u32 ft_sess_get_index(struct se_session *);
 u32 ft_sess_get_port_name(struct se_session *, unsigned char *, u32);

drivers/target/tcm_fc/tfc_conf.c

···
 	.tpg_get_inst_index =		ft_tpg_get_inst_index,
 	.check_stop_free =		ft_check_stop_free,
 	.release_cmd =			ft_release_cmd,
-	.shutdown_session =		ft_sess_shutdown,
 	.close_session =		ft_sess_close,
 	.sess_get_index =		ft_sess_get_index,
 	.sess_get_initiator_sid =	NULL,

drivers/target/tcm_fc/tfc_sess.c

···
  */
 
 /*
- * Determine whether session is allowed to be shutdown in the current context.
- * Returns non-zero if the session should be shutdown.
- */
-int ft_sess_shutdown(struct se_session *se_sess)
-{
-	struct ft_sess *sess = se_sess->fabric_sess_ptr;
-
-	pr_debug("port_id %x\n", sess->port_id);
-	return 1;
-}
-
-/*
  * Remove session and send PRLO.
  * This is called when the ACL is being deleted or queue depth is changing.
  */

drivers/usb/gadget/function/f_tcm.c

···
 	percpu_ida_free(&se_sess->sess_tag_pool, se_cmd->map_tag);
 }
 
-static int usbg_shutdown_session(struct se_session *se_sess)
-{
-	return 0;
-}
-
 static void usbg_close_session(struct se_session *se_sess)
 {
 }
···
 	.tpg_check_prod_mode_write_protect = usbg_check_false,
 	.tpg_get_inst_index		= usbg_tpg_get_inst_index,
 	.release_cmd			= usbg_release_cmd,
-	.shutdown_session		= usbg_shutdown_session,
 	.close_session			= usbg_close_session,
 	.sess_get_index			= usbg_sess_get_index,
 	.sess_get_initiator_sid		= NULL,

drivers/vhost/scsi.c

···
 	percpu_ida_free(&se_sess->sess_tag_pool, se_cmd->map_tag);
 }
 
-static int vhost_scsi_shutdown_session(struct se_session *se_sess)
-{
-	return 0;
-}
-
 static void vhost_scsi_close_session(struct se_session *se_sess)
 {
 	return;
···
 	.tpg_get_inst_index		= vhost_scsi_tpg_get_inst_index,
 	.release_cmd			= vhost_scsi_release_cmd,
 	.check_stop_free		= vhost_scsi_check_stop_free,
-	.shutdown_session		= vhost_scsi_shutdown_session,
 	.close_session			= vhost_scsi_close_session,
 	.sess_get_index			= vhost_scsi_sess_get_index,
 	.sess_get_initiator_sid		= NULL,

drivers/xen/xen-scsiback.c

···
 	percpu_ida_free(&se_sess->sess_tag_pool, se_cmd->map_tag);
 }
 
-static int scsiback_shutdown_session(struct se_session *se_sess)
-{
-	return 0;
-}
-
 static void scsiback_close_session(struct se_session *se_sess)
 {
 }
···
 	.tpg_get_inst_index		= scsiback_tpg_get_inst_index,
 	.check_stop_free		= scsiback_check_stop_free,
 	.release_cmd			= scsiback_release_cmd,
-	.shutdown_session		= scsiback_shutdown_session,
 	.close_session			= scsiback_close_session,
 	.sess_get_index			= scsiback_sess_get_index,
 	.sess_get_initiator_sid		= NULL,