Commit 92d5193b authored by Swen Schillig's avatar Swen Schillig Committed by James Bottomley
Browse files

[SCSI] zfcp: Dont block zfcp_wq with scan 



When running the scsi_scan from the zfcp workqueue and the target
device does not respond, the zfcp workqueue can block until the
scsi_scan hits a timeout. Move the work to the scsi host workqueue,
since this one is also used for the scan from the SCSI midlayer.

Signed-off-by: default avatarSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: default avatarChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@HansenPartnership.com>
parent ada81b74

drivers/s390/scsi/zfcp_aux.c

+2 −3
Original line number Diff line number Diff line
@@ -97,9 +97,7 @@ static void __init zfcp_init_device_configure(char *busid, u64 wwpn, u64 lun) 
	ccw_device_set_online(adapter->ccw_device);



	zfcp_erp_wait(adapter);

	wait_event(adapter->erp_done_wqh,

		   !(atomic_read(&unit->status) &

				ZFCP_STATUS_UNIT_SCSI_WORK_PENDING));

	flush_work(&unit->scsi_work);



	down(&zfcp_data.config_sema);

	zfcp_unit_put(unit);
@@ -279,6 +277,7 @@ struct zfcp_unit *zfcp_unit_enqueue(struct zfcp_port *port, u64 fcp_lun) 


	atomic_set(&unit->refcount, 0);

	init_waitqueue_head(&unit->remove_wq);

	INIT_WORK(&unit->scsi_work, zfcp_scsi_scan);



	unit->port = port;

	unit->fcp_lun = fcp_lun;

drivers/s390/scsi/zfcp_def.h

+1 −1
Original line number Diff line number Diff line
@@ -255,7 +255,6 @@ enum zfcp_wka_status { 
/* logical unit status */

#define ZFCP_STATUS_UNIT_SHARED			0x00000004

#define ZFCP_STATUS_UNIT_READONLY		0x00000008

#define ZFCP_STATUS_UNIT_SCSI_WORK_PENDING	0x00000020



/* FSF request status (this does not have a common part) */

#define ZFCP_STATUS_FSFREQ_TASK_MANAGEMENT	0x00000002
@@ -530,6 +529,7 @@ struct zfcp_unit { 
	struct zfcp_erp_action erp_action;     /* pending error recovery */

        atomic_t               erp_counter;

	struct zfcp_latencies	latencies;

	struct work_struct	scsi_work;

};



/* FSF request */

drivers/s390/scsi/zfcp_erp.c

+4 −46
Original line number Diff line number Diff line
@@ -1176,48 +1176,6 @@ static void zfcp_erp_action_dequeue(struct zfcp_erp_action *erp_action) 
	}

}



struct zfcp_erp_add_work {

	struct zfcp_unit  *unit;

	struct work_struct work;

};



static void zfcp_erp_scsi_scan(struct work_struct *work)

{

	struct zfcp_erp_add_work *p =

		container_of(work, struct zfcp_erp_add_work, work);

	struct zfcp_unit *unit = p->unit;

	struct fc_rport *rport = unit->port->rport;



	if (rport && rport->port_state == FC_PORTSTATE_ONLINE)

		scsi_scan_target(&rport->dev, 0, rport->scsi_target_id,

			 scsilun_to_int((struct scsi_lun *)&unit->fcp_lun), 0);

	atomic_clear_mask(ZFCP_STATUS_UNIT_SCSI_WORK_PENDING, &unit->status);

	zfcp_unit_put(unit);

	wake_up(&unit->port->adapter->erp_done_wqh);

	kfree(p);

}



static void zfcp_erp_schedule_work(struct zfcp_unit *unit)

{

	struct zfcp_erp_add_work *p;



	p = kzalloc(sizeof(*p), GFP_KERNEL);

	if (!p) {

		dev_err(&unit->port->adapter->ccw_device->dev,

			"Registering unit 0x%016Lx on port 0x%016Lx failed\n",

			(unsigned long long)unit->fcp_lun,

			(unsigned long long)unit->port->wwpn);

		return;

	}



	zfcp_unit_get(unit);

	atomic_set_mask(ZFCP_STATUS_UNIT_SCSI_WORK_PENDING, &unit->status);

	INIT_WORK(&p->work, zfcp_erp_scsi_scan);

	p->unit = unit;

	if (!queue_work(zfcp_data.work_queue, &p->work))

		zfcp_unit_put(unit);

}



static void zfcp_erp_action_cleanup(struct zfcp_erp_action *act, int result)

{

	struct zfcp_adapter *adapter = act->adapter;
@@ -1226,11 +1184,11 @@ static void zfcp_erp_action_cleanup(struct zfcp_erp_action *act, int result) 


	switch (act->action) {

	case ZFCP_ERP_ACTION_REOPEN_UNIT:

		flush_work(&port->rport_work);

		if ((result == ZFCP_ERP_SUCCEEDED) && !unit->device) {

			if (!(atomic_read(&unit->status) &

			      ZFCP_STATUS_UNIT_SCSI_WORK_PENDING))

				zfcp_erp_schedule_work(unit);

			zfcp_unit_get(unit);

			if (scsi_queue_work(unit->port->adapter->scsi_host,

					    &unit->scsi_work) <= 0)

				zfcp_unit_put(unit);

		}

		zfcp_unit_put(unit);

		break;

drivers/s390/scsi/zfcp_ext.h

+1 −0
Original line number Diff line number Diff line
@@ -158,6 +158,7 @@ extern void zfcp_scsi_rport_work(struct work_struct *); 
extern void zfcp_scsi_schedule_rport_register(struct zfcp_port *);

extern void zfcp_scsi_schedule_rport_block(struct zfcp_port *);

extern void zfcp_scsi_schedule_rports_block(struct zfcp_adapter *);

extern void zfcp_scsi_scan(struct work_struct *);



/* zfcp_sysfs.c */

extern struct attribute_group zfcp_sysfs_unit_attrs;

drivers/s390/scsi/zfcp_scsi.c

+17 −0
Original line number Diff line number Diff line
@@ -583,6 +583,23 @@ void zfcp_scsi_rport_work(struct work_struct *work) 
}





void zfcp_scsi_scan(struct work_struct *work)

{

	struct zfcp_unit *unit = container_of(work, struct zfcp_unit,

					      scsi_work);

	struct fc_rport *rport;



	flush_work(&unit->port->rport_work);

	rport = unit->port->rport;



	if (rport && rport->port_state == FC_PORTSTATE_ONLINE)

		scsi_scan_target(&rport->dev, 0, rport->scsi_target_id,

				 scsilun_to_int((struct scsi_lun *)

						&unit->fcp_lun), 0);



	zfcp_unit_put(unit);

}



struct fc_function_template zfcp_transport_functions = {

	.show_starget_port_id = 1,

	.show_starget_port_name = 1,

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