Patch "target: fix ALUA transition timeout handling" has been added to the 4.4-stable tree

Patch "target: fix ALUA transition timeout handling" has been added to the 4.4-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    target: fix ALUA transition timeout handling

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     target-fix-alua-transition-timeout-handling.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Mon Dec 18 14:47:43 CET 2017
From: Mike Christie <mchristi@redhat.com>
Date: Thu, 2 Mar 2017 04:59:48 -0600
Subject: target: fix ALUA transition timeout handling

From: Mike Christie <mchristi@redhat.com>


[ Upstream commit d7175373f2745ed4abe5b388d5aabd06304f801e ]

The implicit transition time tells initiators the min time
to wait before timing out a transition. We currently schedule
the transition to occur in tg_pt_gp_implicit_trans_secs
seconds so there is no room for delays. If
core_alua_do_transition_tg_pt_work->core_alua_update_tpg_primary_metadata
needs to write out info to a remote file, then the initiator can
easily time out the operation.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/target/target_core_alua.c |   23 ++++++++---------------
 include/target/target_core_base.h |    2 +-
 2 files changed, 9 insertions(+), 16 deletions(-)

--- a/drivers/target/target_core_alua.c
+++ b/drivers/target/target_core_alua.c
@@ -1010,7 +1010,7 @@ static void core_alua_queue_state_change
 static void core_alua_do_transition_tg_pt_work(struct work_struct *work)
 {
 	struct t10_alua_tg_pt_gp *tg_pt_gp = container_of(work,
-		struct t10_alua_tg_pt_gp, tg_pt_gp_transition_work.work);
+		struct t10_alua_tg_pt_gp, tg_pt_gp_transition_work);
 	struct se_device *dev = tg_pt_gp->tg_pt_gp_dev;
 	bool explicit = (tg_pt_gp->tg_pt_gp_alua_access_status ==
 			 ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG);
@@ -1073,13 +1073,12 @@ static int core_alua_do_transition_tg_pt
 	/*
 	 * Flush any pending transitions
 	 */
-	if (!explicit && tg_pt_gp->tg_pt_gp_implicit_trans_secs &&
-	    atomic_read(&tg_pt_gp->tg_pt_gp_alua_access_state) ==
+	if (!explicit && atomic_read(&tg_pt_gp->tg_pt_gp_alua_access_state) ==
 	    ALUA_ACCESS_STATE_TRANSITION) {
 		/* Just in case */
 		tg_pt_gp->tg_pt_gp_alua_pending_state = new_state;
 		tg_pt_gp->tg_pt_gp_transition_complete = &wait;
-		flush_delayed_work(&tg_pt_gp->tg_pt_gp_transition_work);
+		flush_work(&tg_pt_gp->tg_pt_gp_transition_work);
 		wait_for_completion(&wait);
 		tg_pt_gp->tg_pt_gp_transition_complete = NULL;
 		return 0;
@@ -1114,15 +1113,9 @@ static int core_alua_do_transition_tg_pt
 	atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
 	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
 
-	if (!explicit && tg_pt_gp->tg_pt_gp_implicit_trans_secs) {
-		unsigned long transition_tmo;
-
-		transition_tmo = tg_pt_gp->tg_pt_gp_implicit_trans_secs * HZ;
-		schedule_delayed_work(&tg_pt_gp->tg_pt_gp_transition_work,
-				      transition_tmo);
-	} else {
+	schedule_work(&tg_pt_gp->tg_pt_gp_transition_work);
+	if (explicit) {
 		tg_pt_gp->tg_pt_gp_transition_complete = &wait;
-		schedule_delayed_work(&tg_pt_gp->tg_pt_gp_transition_work, 0);
 		wait_for_completion(&wait);
 		tg_pt_gp->tg_pt_gp_transition_complete = NULL;
 	}
@@ -1690,8 +1683,8 @@ struct t10_alua_tg_pt_gp *core_alua_allo
 	mutex_init(&tg_pt_gp->tg_pt_gp_md_mutex);
 	spin_lock_init(&tg_pt_gp->tg_pt_gp_lock);
 	atomic_set(&tg_pt_gp->tg_pt_gp_ref_cnt, 0);
-	INIT_DELAYED_WORK(&tg_pt_gp->tg_pt_gp_transition_work,
-			  core_alua_do_transition_tg_pt_work);
+	INIT_WORK(&tg_pt_gp->tg_pt_gp_transition_work,
+		  core_alua_do_transition_tg_pt_work);
 	tg_pt_gp->tg_pt_gp_dev = dev;
 	atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state,
 		ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED);
@@ -1799,7 +1792,7 @@ void core_alua_free_tg_pt_gp(
 	dev->t10_alua.alua_tg_pt_gps_counter--;
 	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
 
-	flush_delayed_work(&tg_pt_gp->tg_pt_gp_transition_work);
+	flush_work(&tg_pt_gp->tg_pt_gp_transition_work);
 
 	/*
 	 * Allow a struct t10_alua_tg_pt_gp_member * referenced by
--- a/include/target/target_core_base.h
+++ b/include/target/target_core_base.h
@@ -299,7 +299,7 @@ struct t10_alua_tg_pt_gp {
 	struct list_head tg_pt_gp_lun_list;
 	struct se_lun *tg_pt_gp_alua_lun;
 	struct se_node_acl *tg_pt_gp_alua_nacl;
-	struct delayed_work tg_pt_gp_transition_work;
+	struct work_struct tg_pt_gp_transition_work;
 	struct completion *tg_pt_gp_transition_complete;
 };
 


Patches currently in stable-queue which might be from mchristi@redhat.com are

queue-4.4/target-use-system-workqueue-for-alua-transitions.patch
queue-4.4/target-iscsi-fix-a-race-condition-in-iscsit_add_reject_from_cmd.patch
queue-4.4/target-fix-alua-transition-timeout-handling.patch
queue-4.4/target-fix-race-during-implicit-transition-work-flushes.patch