[Devel] [PATCH RHEL7 COMMIT] ms/target: Fix TAS handling for multi-session se_node_acls

[Konstantin Khorenko]

The commit is pushed to "branch-rh7-3.10.0-693.21.1.vz7.46.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh7-3.10.0-693.21.1.vz7.46.2
------>
commit e0712c21dd35bcc357848ef9c2388e3ff6e88f42
Author: Nicholas Bellinger <nab at linux-iscsi.org>
Date:   Mon Apr 2 17:28:28 2018 +0300

    ms/target: Fix TAS handling for multi-session se_node_acls
    
    ML: ebde1ca5a908b10312db4ecd7553e3ba039319ab
    
    This patch fixes a bug in TMR task aborted status (TAS)
    handling when multiple sessions are connected to the
    same target WWPN endpoint and se_node_acl descriptor,
    resulting in TASK_ABORTED status to not be generated
    for aborted se_cmds on the remote port.
    
    This is due to core_tmr_handle_tas_abort() incorrectly
    comparing se_node_acl instead of se_session, for which
    the multi-session case is expected to be sharing the
    same se_node_acl.
    
    Instead, go ahead and update core_tmr_handle_tas_abort()
    to compare tmr_sess + cmd->se_sess in order to determine
    if the LUN_RESET was received on a different I_T nexus,
    and TASK_ABORTED status response needs to be generated.
    
    Reviewed-by: Christoph Hellwig <hch at lst.de>
    Cc: Quinn Tran <quinn.tran at qlogic.com>
    Cc: Himanshu Madhani <himanshu.madhani at qlogic.com>
    Cc: Sagi Grimberg <sagig at mellanox.com>
    Cc: Hannes Reinecke <hare at suse.de>
    Cc: Andy Grover <agrover at redhat.com>
    Cc: Mike Christie <mchristi at redhat.com>
    Cc: stable at vger.kernel.org # 3.10+
    Signed-off-by: Nicholas Bellinger <nab at linux-iscsi.org>
    Signed-off-by: Andrei Vagin <avagin at openvz.org>
---
 drivers/target/target_core_tmr.c | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/drivers/target/target_core_tmr.c b/drivers/target/target_core_tmr.c
index 99bc3d4db737..8f935fb2734d 100644
--- a/drivers/target/target_core_tmr.c
+++ b/drivers/target/target_core_tmr.c
@@ -79,7 +79,7 @@ void core_tmr_release_req(struct se_tmr_req *tmr)
 }
 
 static void core_tmr_handle_tas_abort(
-	struct se_node_acl *tmr_nacl,
+	struct se_session *tmr_sess,
 	struct se_cmd *cmd,
 	int tas)
 {
@@ -87,7 +87,7 @@ static void core_tmr_handle_tas_abort(
 	/*
 	 * TASK ABORTED status (TAS) bit support
 	 */
-	if ((tmr_nacl && (tmr_nacl != cmd->se_sess->se_node_acl)) && tas) {
+	if (tmr_sess && tmr_sess != cmd->se_sess && tas) {
 		remove = false;
 		transport_send_task_abort(cmd);
 	}
@@ -281,7 +281,7 @@ static void core_tmr_drain_tmr_list(
 static void core_tmr_drain_state_list(
 	struct se_device *dev,
 	struct se_cmd *prout_cmd,
-	struct se_node_acl *tmr_nacl,
+	struct se_session *tmr_sess,
 	int tas,
 	struct list_head *preempt_and_abort_list)
 {
@@ -372,7 +372,7 @@ static void core_tmr_drain_state_list(
 		cancel_work_sync(&cmd->work);
 		transport_wait_for_tasks(cmd);
 
-		core_tmr_handle_tas_abort(tmr_nacl, cmd, tas);
+		core_tmr_handle_tas_abort(tmr_sess, cmd, tas);
 		target_put_sess_cmd(cmd);
 	}
 }
@@ -385,6 +385,7 @@ int core_tmr_lun_reset(
 {
 	struct se_node_acl *tmr_nacl = NULL;
 	struct se_portal_group *tmr_tpg = NULL;
+	struct se_session *tmr_sess = NULL;
 	int tas;
         /*
 	 * TASK_ABORTED status bit, this is configurable via ConfigFS
@@ -403,8 +404,9 @@ int core_tmr_lun_reset(
 	 * or struct se_device passthrough..
 	 */
 	if (tmr && tmr->task_cmd && tmr->task_cmd->se_sess) {
-		tmr_nacl = tmr->task_cmd->se_sess->se_node_acl;
-		tmr_tpg = tmr->task_cmd->se_sess->se_tpg;
+		tmr_sess = tmr->task_cmd->se_sess;
+		tmr_nacl = tmr_sess->se_node_acl;
+		tmr_tpg = tmr_sess->se_tpg;
 		if (tmr_nacl && tmr_tpg) {
 			pr_debug("LUN_RESET: TMR caller fabric: %s"
 				" initiator port %s\n",
@@ -417,7 +419,7 @@ int core_tmr_lun_reset(
 		dev->transport->name, tas);
 
 	core_tmr_drain_tmr_list(dev, tmr, preempt_and_abort_list);
-	core_tmr_drain_state_list(dev, prout_cmd, tmr_nacl, tas,
+	core_tmr_drain_state_list(dev, prout_cmd, tmr_sess, tas,
 				preempt_and_abort_list);
 
 	/*