3 files changed, 65 insertions, 75 deletions

diff --git a/drivers/scsi/libsas/sas_ata.c b/drivers/scsi/libsas/sas_ata.c
index 903bb441b9f9..4c2a1402373c 100644
--- a/drivers/scsi/libsas/sas_ata.c
+++ b/drivers/scsi/libsas/sas_ata.c
@@ -93,21 +93,30 @@ static enum ata_completion_errors sas_to_ata_err(struct task_status_struct *ts)
 static void sas_ata_task_done(struct sas_task *task)
 {
 	struct ata_queued_cmd *qc = task->uldd_task;
-	struct domain_device *dev;
+	struct domain_device *dev = task->dev;
 	struct task_status_struct *stat = &task->task_status;
 	struct ata_task_resp *resp = (struct ata_task_resp *)stat->buf;
-	struct sas_ha_struct *sas_ha;
+	struct sas_ha_struct *sas_ha = dev->port->ha;
 	enum ata_completion_errors ac;
 	unsigned long flags;
 	struct ata_link *link;
 	struct ata_port *ap;
 
+	spin_lock_irqsave(&dev->done_lock, flags);
+	if (test_bit(SAS_HA_FROZEN, &sas_ha->state))
+		task = NULL;
+	else if (qc && qc->scsicmd)
+		ASSIGN_SAS_TASK(qc->scsicmd, NULL);
+	spin_unlock_irqrestore(&dev->done_lock, flags);
+
+	/* check if libsas-eh got to the task before us */
+	if (unlikely(!task))
+		return;
+
 	if (!qc)
 		goto qc_already_gone;
 
 	ap = qc->ap;
-	dev = ap->private_data;
-	sas_ha = dev->port->ha;
 	link = &ap->link;
 
 	spin_lock_irqsave(ap->lock, flags);
@@ -156,8 +165,6 @@ static void sas_ata_task_done(struct sas_task *task)
 	}
 
 	qc->lldd_task = NULL;
-	if (qc->scsicmd)
-		ASSIGN_SAS_TASK(qc->scsicmd, NULL);
 	ata_qc_complete(qc);
 	spin_unlock_irqrestore(ap->lock, flags);
 
@@ -633,22 +640,6 @@ void sas_ata_strategy_handler(struct Scsi_Host *shost)
 	sas_enable_revalidation(sas_ha);
 }
 
-int sas_ata_timed_out(struct scsi_cmnd *cmd, struct sas_task *task,
-		      enum blk_eh_timer_return *rtn)
-{
-	struct domain_device *ddev = cmd_to_domain_dev(cmd);
-
-	if (!dev_is_sata(ddev) || task)
-		return 0;
-
-	/* we're a sata device with no task, so this must be a libata
-	 * eh timeout.  Ideally should hook into libata timeout
-	 * handling, but there's no point, it just wants to activate
-	 * the eh thread */
-	*rtn = BLK_EH_NOT_HANDLED;
-	return 1;
-}
-
 int sas_ata_eh(struct Scsi_Host *shost, struct list_head *work_q,
 	       struct list_head *done_q)
 {
diff --git a/drivers/scsi/libsas/sas_internal.h b/drivers/scsi/libsas/sas_internal.h
index ebe9b81ddef5..662ffcba99d2 100644
--- a/drivers/scsi/libsas/sas_internal.h
+++ b/drivers/scsi/libsas/sas_internal.h
@@ -142,6 +142,7 @@ static inline struct domain_device *sas_alloc_device(void)
 		INIT_LIST_HEAD(&dev->dev_list_node);
 		INIT_LIST_HEAD(&dev->disco_list_node);
 		kref_init(&dev->kref);
+		spin_lock_init(&dev->done_lock);
 	}
 	return dev;
 }
diff --git a/drivers/scsi/libsas/sas_scsi_host.c b/drivers/scsi/libsas/sas_scsi_host.c
index 50db8f971a06..0e3fdba7b510 100644
--- a/drivers/scsi/libsas/sas_scsi_host.c
+++ b/drivers/scsi/libsas/sas_scsi_host.c
@@ -119,9 +119,19 @@ static void sas_end_task(struct scsi_cmnd *sc, struct sas_task *task)
 static void sas_scsi_task_done(struct sas_task *task)
 {
 	struct scsi_cmnd *sc = task->uldd_task;
+	struct domain_device *dev = task->dev;
+	struct sas_ha_struct *ha = dev->port->ha;
+	unsigned long flags;
+
+	spin_lock_irqsave(&dev->done_lock, flags);
+	if (test_bit(SAS_HA_FROZEN, &ha->state))
+		task = NULL;
+	else
+		ASSIGN_SAS_TASK(sc, NULL);
+	spin_unlock_irqrestore(&dev->done_lock, flags);
 
-	if (unlikely(task->task_state_flags & SAS_TASK_STATE_ABORTED)) {
-		/* Aborted tasks will be completed by the error handler */
+	if (unlikely(!task)) {
+		/* task will be completed by the error handler */
 		SAS_DPRINTK("task done but aborted\n");
 		return;
 	}
@@ -133,7 +143,6 @@ static void sas_scsi_task_done(struct sas_task *task)
 		return;
 	}
 
-	ASSIGN_SAS_TASK(sc, NULL);
 	sas_end_task(sc, task);
 	sc->scsi_done(sc);
 }
@@ -298,6 +307,7 @@ enum task_disposition {
 	TASK_IS_DONE,
 	TASK_IS_ABORTED,
 	TASK_IS_AT_LU,
+	TASK_IS_NOT_AT_HA,
 	TASK_IS_NOT_AT_LU,
 	TASK_ABORT_FAILED,
 };
@@ -314,19 +324,18 @@ static enum task_disposition sas_scsi_find_task(struct sas_task *task)
 		struct scsi_core *core = &ha->core;
 		struct sas_task *t, *n;
 
+		mutex_lock(&core->task_queue_flush);
 		spin_lock_irqsave(&core->task_queue_lock, flags);
-		list_for_each_entry_safe(t, n, &core->task_queue, list) {
+		list_for_each_entry_safe(t, n, &core->task_queue, list)
 			if (task == t) {
 				list_del_init(&t->list);
-				spin_unlock_irqrestore(&core->task_queue_lock,
-						       flags);
-				SAS_DPRINTK("%s: task 0x%p aborted from "
-					    "task_queue\n",
-					    __func__, task);
-				return TASK_IS_ABORTED;
+				break;
 			}
-		}
 		spin_unlock_irqrestore(&core->task_queue_lock, flags);
+		mutex_unlock(&core->task_queue_flush);
+
+		if (task == t)
+			return TASK_IS_NOT_AT_HA;
 	}
 
 	for (i = 0; i < 5; i++) {
@@ -499,8 +508,7 @@ try_bus_reset:
 }
 
 static int sas_eh_handle_sas_errors(struct Scsi_Host *shost,
-				    struct list_head *work_q,
-				    struct list_head *done_q)
+				    struct list_head *work_q)
 {
 	struct scsi_cmnd *cmd, *n;
 	enum task_disposition res = TASK_IS_DONE;
@@ -511,7 +519,16 @@ static int sas_eh_handle_sas_errors(struct Scsi_Host *shost,
 
 Again:
 	list_for_each_entry_safe(cmd, n, work_q, eh_entry) {
-		struct sas_task *task = TO_SAS_TASK(cmd);
+		struct domain_device *dev = cmd_to_domain_dev(cmd);
+		struct sas_task *task;
+
+		spin_lock_irqsave(&dev->done_lock, flags);
+		/* by this point the lldd has either observed
+		 * SAS_HA_FROZEN and is leaving the task alone, or has
+		 * won the race with eh and decided to complete it
+		 */
+		task = TO_SAS_TASK(cmd);
+		spin_unlock_irqrestore(&dev->done_lock, flags);
 
 		if (!task)
 			continue;
@@ -534,6 +551,14 @@ Again:
 		cmd->eh_eflags = 0;
 
 		switch (res) {
+		case TASK_IS_NOT_AT_HA:
+			SAS_DPRINTK("%s: task 0x%p is not at ha: %s\n",
+				    __func__, task,
+				    cmd->retries ? "retry" : "aborted");
+			if (cmd->retries)
+				cmd->retries--;
+			sas_eh_finish_cmd(cmd);
+			continue;
 		case TASK_IS_DONE:
 			SAS_DPRINTK("%s: task 0x%p is done\n", __func__,
 				    task);
@@ -635,7 +660,8 @@ void sas_scsi_recover_host(struct Scsi_Host *shost)
 	 * Deal with commands that still have SAS tasks (i.e. they didn't
 	 * complete via the normal sas_task completion mechanism)
 	 */
-	if (sas_eh_handle_sas_errors(shost, &eh_work_q, &ha->eh_done_q))
+	set_bit(SAS_HA_FROZEN, &ha->state);
+	if (sas_eh_handle_sas_errors(shost, &eh_work_q))
 		goto out;
 
 	/*
@@ -649,6 +675,10 @@ void sas_scsi_recover_host(struct Scsi_Host *shost)
 			scsi_eh_ready_devs(shost, &eh_work_q, &ha->eh_done_q);
 
 out:
+	clear_bit(SAS_HA_FROZEN, &ha->state);
+	if (ha->lldd_max_execute_num > 1)
+		wake_up_process(ha->core.queue_thread);
+
 	/* now link into libata eh --- if we have any ata devices */
 	sas_ata_strategy_handler(shost);
 
@@ -660,43 +690,7 @@ out:
 
 enum blk_eh_timer_return sas_scsi_timed_out(struct scsi_cmnd *cmd)
 {
-	struct sas_task *task = TO_SAS_TASK(cmd);
-	unsigned long flags;
-	enum blk_eh_timer_return rtn;
-
-	if (sas_ata_timed_out(cmd, task, &rtn))
-		return rtn;
-
-	if (!task) {
-		cmd->request->timeout /= 2;
-		SAS_DPRINTK("command 0x%p, task 0x%p, gone: %s\n",
-			    cmd, task, (cmd->request->timeout ?
-			    "BLK_EH_RESET_TIMER" : "BLK_EH_NOT_HANDLED"));
-		if (!cmd->request->timeout)
-			return BLK_EH_NOT_HANDLED;
-		return BLK_EH_RESET_TIMER;
-	}
-
-	spin_lock_irqsave(&task->task_state_lock, flags);
-	BUG_ON(task->task_state_flags & SAS_TASK_STATE_ABORTED);
-	if (task->task_state_flags & SAS_TASK_STATE_DONE) {
-		spin_unlock_irqrestore(&task->task_state_lock, flags);
-		SAS_DPRINTK("command 0x%p, task 0x%p, timed out: "
-			    "BLK_EH_HANDLED\n", cmd, task);
-		return BLK_EH_HANDLED;
-	}
-	if (!(task->task_state_flags & SAS_TASK_AT_INITIATOR)) {
-		spin_unlock_irqrestore(&task->task_state_lock, flags);
-		SAS_DPRINTK("command 0x%p, task 0x%p, not at initiator: "
-			    "BLK_EH_RESET_TIMER\n",
-			    cmd, task);
-		return BLK_EH_RESET_TIMER;
-	}
-	task->task_state_flags |= SAS_TASK_STATE_ABORTED;
-	spin_unlock_irqrestore(&task->task_state_lock, flags);
-
-	SAS_DPRINTK("command 0x%p, task 0x%p, timed out: BLK_EH_NOT_HANDLED\n",
-		    cmd, task);
+	scmd_printk(KERN_DEBUG, cmd, "command %p timed out\n", cmd);
 
 	return BLK_EH_NOT_HANDLED;
 }
@@ -861,9 +855,11 @@ static void sas_queue(struct sas_ha_struct *sas_ha)
 	int res;
 	struct sas_internal *i = to_sas_internal(core->shost->transportt);
 
+	mutex_lock(&core->task_queue_flush);
 	spin_lock_irqsave(&core->task_queue_lock, flags);
 	while (!kthread_should_stop() &&
-	       !list_empty(&core->task_queue)) {
+	       !list_empty(&core->task_queue) &&
+	       !test_bit(SAS_HA_FROZEN, &sas_ha->state)) {
 
 		can_queue = sas_ha->lldd_queue_size - core->task_queue_size;
 		if (can_queue >= 0) {
@@ -899,6 +895,7 @@ static void sas_queue(struct sas_ha_struct *sas_ha)
 		}
 	}
 	spin_unlock_irqrestore(&core->task_queue_lock, flags);
+	mutex_unlock(&core->task_queue_flush);
 }
 
 /**
@@ -925,6 +922,7 @@ int sas_init_queue(struct sas_ha_struct *sas_ha)
 	struct scsi_core *core = &sas_ha->core;
 
 	spin_lock_init(&core->task_queue_lock);
+	mutex_init(&core->task_queue_flush);
 	core->task_queue_size = 0;
 	INIT_LIST_HEAD(&core->task_queue);