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Commit f731e5c7 authored by Bart Van Assche's avatar Bart Van Assche Committed by Sasha Levin
Browse files

scsi_transport_srp: Introduce srp_wait_for_queuecommand() 



[ Upstream commit be34c62ddf39d1931780b07a6f4241393e4ba2ee ]

Introduce the helper function srp_wait_for_queuecommand().
Move the definition of scsi_request_fn_active(). Add a comment
above srp_wait_for_queuecommand() that support for scsi-mq needs
to be added.

This patch does not change any functionality. A second call to
srp_wait_for_queuecommand() will be introduced in the next patch.

Signed-off-by: default avatarBart Van Assche <bart.vanassche@sandisk.com>
Cc: James Bottomley <JBottomley@Odin.com>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Sebastian Parschauer <sebastian.riemer@profitbricks.com>
Cc: <stable@vger.kernel.org> #v3.13
Signed-off-by: default avatarDoug Ledford <dledford@redhat.com>
Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
parent ec4dc9ec

drivers/scsi/scsi_transport_srp.c

+31 −23
Original line number Diff line number Diff line
@@ -396,6 +396,36 @@ static void srp_reconnect_work(struct work_struct *work) 
	}

}



/**

 * scsi_request_fn_active() - number of kernel threads inside scsi_request_fn()

 * @shost: SCSI host for which to count the number of scsi_request_fn() callers.

 *

 * To do: add support for scsi-mq in this function.

 */

static int scsi_request_fn_active(struct Scsi_Host *shost)

{

	struct scsi_device *sdev;

	struct request_queue *q;

	int request_fn_active = 0;



	shost_for_each_device(sdev, shost) {

		q = sdev->request_queue;



		spin_lock_irq(q->queue_lock);

		request_fn_active += q->request_fn_active;

		spin_unlock_irq(q->queue_lock);

	}



	return request_fn_active;

}



/* Wait until ongoing shost->hostt->queuecommand() calls have finished. */

static void srp_wait_for_queuecommand(struct Scsi_Host *shost)

{

	while (scsi_request_fn_active(shost))

		msleep(20);

}



static void __rport_fail_io_fast(struct srp_rport *rport)

{

	struct Scsi_Host *shost = rport_to_shost(rport);
@@ -503,27 +533,6 @@ void srp_start_tl_fail_timers(struct srp_rport *rport) 
}

EXPORT_SYMBOL(srp_start_tl_fail_timers);



/**

 * scsi_request_fn_active() - number of kernel threads inside scsi_request_fn()

 * @shost: SCSI host for which to count the number of scsi_request_fn() callers.

 */

static int scsi_request_fn_active(struct Scsi_Host *shost)

{

	struct scsi_device *sdev;

	struct request_queue *q;

	int request_fn_active = 0;



	shost_for_each_device(sdev, shost) {

		q = sdev->request_queue;



		spin_lock_irq(q->queue_lock);

		request_fn_active += q->request_fn_active;

		spin_unlock_irq(q->queue_lock);

	}



	return request_fn_active;

}



/**

 * srp_reconnect_rport() - reconnect to an SRP target port

 * @rport: SRP target port.
@@ -559,8 +568,7 @@ int srp_reconnect_rport(struct srp_rport *rport) 
	if (res)

		goto out;

	scsi_target_block(&shost->shost_gendev);

	while (scsi_request_fn_active(shost))

		msleep(20);

	srp_wait_for_queuecommand(shost);

	res = rport->state != SRP_RPORT_LOST ? i->f->reconnect(rport) : -ENODEV;

	pr_debug("%s (state %d): transport.reconnect() returned %d\n",

		 dev_name(&shost->shost_gendev), rport->state, res);