[Devel] [PATCH RHEL7 COMMIT] ms/target: Fix target_release_cmd_kref shutdown comp leak

[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 60377be1b944ab89acaa627e4a19327c810151f9
Author: Himanshu Madhani <himanshu.madhani at qlogic.com>
Date:   Mon Apr 2 17:28:29 2018 +0300

    ms/target: Fix target_release_cmd_kref shutdown comp leak
    
    ML: 5e47f1985d7107331c3f64fb3ec83d66fd73577e
    
    This patch fixes an active I/O shutdown bug for fabric
    drivers using target_wait_for_sess_cmds(), where se_cmd
    descriptor shutdown would result in hung tasks waiting
    indefinitely for se_cmd->cmd_wait_comp to complete().
    
    To address this bug, drop the incorrect list_del_init()
    usage in target_wait_for_sess_cmds() and always complete()
    during se_cmd target_release_cmd_kref() put, in order to
    let caller invoke the final fabric release callback
    into se_cmd->se_tfo->release_cmd() code.
    
    Reported-by: Himanshu Madhani <himanshu.madhani at qlogic.com>
    Tested-by: Himanshu Madhani <himanshu.madhani at qlogic.com>
    Signed-off-by: Himanshu Madhani <himanshu.madhani at qlogic.com>
    Cc: stable at vger.kernel.org
    Signed-off-by: Nicholas Bellinger <nab at linux-iscsi.org>
    Signed-off-by: Andrei Vagin <avagin at openvz.org>
---
 drivers/target/target_core_transport.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index dc10e162ef93..9b187cf1c5b0 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -2607,8 +2607,6 @@ void target_wait_for_sess_cmds(struct se_session *se_sess)
 
 	list_for_each_entry_safe(se_cmd, tmp_cmd,
 				&se_sess->sess_wait_list, se_cmd_list) {
-		list_del_init(&se_cmd->se_cmd_list);
-
 		pr_debug("Waiting for se_cmd: %p t_state: %d, fabric state:"
 			" %d\n", se_cmd, se_cmd->t_state,
 			se_cmd->se_tfo->get_cmd_state(se_cmd));