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

Documentation/target/tcm_mod_builder.py

@@ -294,7 +294,6 @@ def tcm_mod_build_configfs(proto_ident, fabric_mod_dir_var, fabric_mod_name):
 	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"
@@ -467,13 +466,6 @@ def tcm_mod_dump_fabric_ops(proto_ident, fabric_mod_dir_var, fabric_mod_name):
 			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"
 			buf += "{\n"

drivers/infiniband/ulp/srpt/ib_srpt.c

@@ -1960,14 +1960,6 @@ static void __srpt_close_all_ch(struct srpt_device *sdev)
 	}
 }
 
-/**
- * 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);
@@ -3287,7 +3279,6 @@ static const struct target_core_fabric_ops srpt_template = {
 	.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

@@ -601,11 +601,6 @@ static int tcm_loop_get_cmd_state(struct se_cmd *se_cmd)
 	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;
@@ -1243,7 +1238,6 @@ static const struct target_core_fabric_ops loop_ops = {
 	.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

@@ -1726,11 +1726,6 @@ static void sbp_release_cmd(struct se_cmd *se_cmd)
 	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;
@@ -2349,7 +2344,6 @@ static const struct target_core_fabric_ops sbp_ops = {
 	.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

@@ -385,10 +385,6 @@ static int target_fabric_tf_ops_check(const struct target_core_fabric_ops *tfo)
 		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

@@ -353,7 +353,10 @@ static void target_shutdown_sessions(struct se_node_acl *acl)
 		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

@@ -139,7 +139,6 @@ extern unsigned int ft_debug_logging;
  * 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

@@ -442,7 +442,6 @@ static const struct target_core_fabric_ops ft_fabric_ops = {
 	.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

@@ -302,18 +302,6 @@ static void ft_sess_delete_all(struct ft_tport *tport)
  * TCM ops for sessions.
  */
 
-/*
- * 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

@@ -1290,11 +1290,6 @@ static void usbg_release_cmd(struct se_cmd *se_cmd)
 	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)
 {
 }
@@ -1735,7 +1730,6 @@ static const struct target_core_fabric_ops usbg_ops = {
 	.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

@@ -333,11 +333,6 @@ static void vhost_scsi_release_cmd(struct se_cmd *se_cmd)
 	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;
@@ -2114,7 +2109,6 @@ static struct target_core_fabric_ops vhost_scsi_ops = {
 	.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

@@ -1399,11 +1399,6 @@ static void scsiback_release_cmd(struct se_cmd *se_cmd)
 	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)
 {
 }
@@ -1841,7 +1836,6 @@ static const struct target_core_fabric_ops scsiback_ops = {
 	.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,