Commit b218a0d8 authored by Darrick J. Wong's avatar Darrick J. Wong Committed by James Bottomley
Browse files

[SCSI] libsas: Don't give scsi_cmnds to the EH if they never made it to the... 


[SCSI] libsas: Don't give scsi_cmnds to the EH if they never made it to the SAS LLDD or have already returned

On a system with many SAS targets, it appears possible that a scsi_cmnd
can time out without ever making it to the SAS LLDD or at the same time
that a completion is occurring.  In both of these cases, telling the
LLDD to abort the sas_task makes no sense because the LLDD won't know
about the sas_task; what we really want to do is to increase the timer.
Note that this involves creating another sas_task bit to indicate
whether or not the task has been sent to the LLDD; I could have
implemented this by slightly redefining SAS_TASK_STATE_PENDING, but
this way seems cleaner.

This second version amends the aic94xx portion to set the
TASK_AT_INITIATOR flag for all sas_tasks that were passed to
lldd_execute_task.

Signed-off-by: default avatarDarrick J. Wong <djwong@us.ibm.com>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@SteelEye.com>
parent bf451207

drivers/scsi/aic94xx/aic94xx_task.c

+9 −0
Original line number Diff line number Diff line
@@ -349,6 +349,7 @@ Again: 


	spin_lock_irqsave(&task->task_state_lock, flags);

	task->task_state_flags &= ~SAS_TASK_STATE_PENDING;

	task->task_state_flags &= ~SAS_TASK_AT_INITIATOR;

	task->task_state_flags |= SAS_TASK_STATE_DONE;

	if (unlikely((task->task_state_flags & SAS_TASK_STATE_ABORTED))) {

		spin_unlock_irqrestore(&task->task_state_lock, flags);
@@ -557,6 +558,7 @@ int asd_execute_task(struct sas_task *task, const int num, 
	struct sas_task *t = task;

	struct asd_ascb *ascb = NULL, *a;

	struct asd_ha_struct *asd_ha = task->dev->port->ha->lldd_ha;

	unsigned long flags;



	res = asd_can_queue(asd_ha, num);

	if (res)
@@ -599,6 +601,10 @@ int asd_execute_task(struct sas_task *task, const int num, 
		}

		if (res)

			goto out_err_unmap;



		spin_lock_irqsave(&t->task_state_lock, flags);

		t->task_state_flags |= SAS_TASK_AT_INITIATOR;

		spin_unlock_irqrestore(&t->task_state_lock, flags);

	}

	list_del_init(&alist);
@@ -617,6 +623,9 @@ out_err_unmap: 
			if (a == b)

				break;

			t = a->uldd_task;

			spin_lock_irqsave(&t->task_state_lock, flags);

			t->task_state_flags &= ~SAS_TASK_AT_INITIATOR;

			spin_unlock_irqrestore(&t->task_state_lock, flags);

			switch (t->task_proto) {

			case SATA_PROTO:

			case SAS_PROTO_STP:

drivers/scsi/libsas/sas_scsi_host.c

+7 −0
Original line number Diff line number Diff line
@@ -542,6 +542,13 @@ enum scsi_eh_timer_return sas_scsi_timed_out(struct scsi_cmnd *cmd) 
			    cmd, task);

		return 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: "

			    "EH_RESET_TIMER\n",

			    cmd, task);

		return EH_RESET_TIMER;

	}

	task->task_state_flags |= SAS_TASK_STATE_ABORTED;

	spin_unlock_irqrestore(&task->task_state_lock, flags);

include/scsi/libsas.h

+1 −0
Original line number Diff line number Diff line
@@ -554,6 +554,7 @@ struct sas_task { 
#define SAS_TASK_STATE_DONE         2

#define SAS_TASK_STATE_ABORTED      4

#define SAS_TASK_INITIATOR_ABORTED  8

#define SAS_TASK_AT_INITIATOR       16



static inline struct sas_task *sas_alloc_task(gfp_t flags)

{

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