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Commit 143bb6bf authored by Christof Schmitt's avatar Christof Schmitt Committed by James Bottomley
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[SCSI] zfcp: Defer resource allocation to first ccw_set_online call 



So far, zfcp allocated all resources required for FCP
adapters/subchannels when the device was discovered in the ccw_probe
callback. If there are lots of unused FCP subchannels attached to a
system, this is a waste of resources. To alleviate this, defer the
resource allocation to the first call to ccw_set_online. To avoid
disruptions during possible following calls to ccw_set_offline and
then ccw_set_online, keep the adapter resources until the device is
finally being removed via ccw_remove. While doing this, also manage
the zfcp erp thread together with all other adapter resources in
zfcp_adapter_enqueue/dequeue.

Reviewed-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@suse.de>
parent 98fc4d5c

drivers/s390/scsi/zfcp_aux.c

+6 −0
Original line number Diff line number Diff line
@@ -541,6 +541,9 @@ int zfcp_adapter_enqueue(struct ccw_device *ccw_device) 
	rwlock_init(&adapter->erp_lock);

	rwlock_init(&adapter->abort_lock);



	if (zfcp_erp_thread_setup(adapter))

		goto erp_thread_failed;



	INIT_WORK(&adapter->stat_work, _zfcp_status_read_scheduler);

	INIT_WORK(&adapter->scan_work, _zfcp_fc_scan_ports_later);
@@ -561,6 +564,8 @@ int zfcp_adapter_enqueue(struct ccw_device *ccw_device) 
		return 0;



sysfs_failed:

	zfcp_erp_thread_kill(adapter);

erp_thread_failed:

	zfcp_fc_gs_destroy(adapter);

generic_services_failed:

	zfcp_destroy_adapter_work_queue(adapter);
@@ -602,6 +607,7 @@ void zfcp_adapter_dequeue(struct zfcp_adapter *adapter) 
		return;



	zfcp_fc_gs_destroy(adapter);

	zfcp_erp_thread_kill(adapter);

	zfcp_destroy_adapter_work_queue(adapter);

	zfcp_dbf_adapter_unregister(adapter->dbf);

	zfcp_free_low_mem_buffers(adapter);

drivers/s390/scsi/zfcp_ccw.c

+43 −31
Original line number Diff line number Diff line
@@ -18,6 +18,9 @@ static int zfcp_ccw_suspend(struct ccw_device *cdev) 
{

	struct zfcp_adapter *adapter = dev_get_drvdata(&cdev->dev);



	if (!adapter)

		return 0;



	down(&zfcp_data.config_sema);



	zfcp_erp_adapter_shutdown(adapter, 0, "ccsusp1", NULL);
@@ -33,6 +36,9 @@ static int zfcp_ccw_activate(struct ccw_device *cdev) 
{

	struct zfcp_adapter *adapter = dev_get_drvdata(&cdev->dev);



	if (!adapter)

		return 0;



	zfcp_erp_modify_adapter_status(adapter, "ccresu1", NULL,

				       ZFCP_STATUS_COMMON_RUNNING, ZFCP_SET);

	zfcp_erp_adapter_reopen(adapter, ZFCP_STATUS_COMMON_ERP_FAILED,
@@ -63,25 +69,14 @@ int zfcp_ccw_priv_sch(struct zfcp_adapter *adapter) 
 * zfcp_ccw_probe - probe function of zfcp driver

 * @ccw_device: pointer to belonging ccw device

 *

 * This function gets called by the common i/o layer and sets up the initial

 * data structures for each fcp adapter, which was detected by the system.

 * Also the sysfs files for this adapter will be created by this function.

 * In addition the nameserver port will be added to the ports of the adapter

 * and its sysfs representation will be created too.

 * This function gets called by the common i/o layer for each FCP

 * device found on the current system. This is only a stub to make cio

 * work: To only allocate adapter resources for devices actually used,

 * the allocation is deferred to the first call to ccw_set_online.

 */

static int zfcp_ccw_probe(struct ccw_device *ccw_device)

{

	int retval = 0;



	down(&zfcp_data.config_sema);

	if (zfcp_adapter_enqueue(ccw_device)) {

		dev_err(&ccw_device->dev,

			"Setting up data structures for the "

			"FCP adapter failed\n");

		retval = -EINVAL;

	}

	up(&zfcp_data.config_sema);

	return retval;

	return 0;

}



/**
@@ -102,8 +97,11 @@ static void zfcp_ccw_remove(struct ccw_device *ccw_device) 
	LIST_HEAD(port_remove_lh);



	ccw_device_set_offline(ccw_device);



	down(&zfcp_data.config_sema);

	adapter = dev_get_drvdata(&ccw_device->dev);

	if (!adapter)

		goto out;



	write_lock_irq(&zfcp_data.config_lock);

	list_for_each_entry_safe(port, p, &adapter->port_list_head, list) {
@@ -129,6 +127,7 @@ static void zfcp_ccw_remove(struct ccw_device *ccw_device) 
	wait_event(adapter->remove_wq, atomic_read(&adapter->refcount) == 0);

	zfcp_adapter_dequeue(adapter);



out:

	up(&zfcp_data.config_sema);

}
@@ -136,22 +135,33 @@ static void zfcp_ccw_remove(struct ccw_device *ccw_device) 
 * zfcp_ccw_set_online - set_online function of zfcp driver

 * @ccw_device: pointer to belonging ccw device

 *

 * This function gets called by the common i/o layer and sets an adapter

 * into state online. Setting an fcp device online means that it will be

 * registered with the SCSI stack, that the QDIO queues will be set up

 * and that the adapter will be opened (asynchronously).

 * This function gets called by the common i/o layer and sets an

 * adapter into state online.  The first call will allocate all

 * adapter resources that will be retained until the device is removed

 * via zfcp_ccw_remove.

 *

 * Setting an fcp device online means that it will be registered with

 * the SCSI stack, that the QDIO queues will be set up and that the

 * adapter will be opened.

 */

static int zfcp_ccw_set_online(struct ccw_device *ccw_device)

{

	struct zfcp_adapter *adapter;

	int retval;

	int ret = 0;



	down(&zfcp_data.config_sema);

	adapter = dev_get_drvdata(&ccw_device->dev);



	retval = zfcp_erp_thread_setup(adapter);

	if (retval)

	if (!adapter) {

		ret = zfcp_adapter_enqueue(ccw_device);

		if (ret) {

			dev_err(&ccw_device->dev,

				"Setting up data structures for the "

				"FCP adapter failed\n");

			goto out;

		}

		adapter = dev_get_drvdata(&ccw_device->dev);

	}



	/* initialize request counter */

	BUG_ON(!zfcp_reqlist_isempty(adapter));
@@ -162,13 +172,11 @@ static int zfcp_ccw_set_online(struct ccw_device *ccw_device) 
	zfcp_erp_adapter_reopen(adapter, ZFCP_STATUS_COMMON_ERP_FAILED,

				"ccsonl2", NULL);

	zfcp_erp_wait(adapter);

	up(&zfcp_data.config_sema);

	flush_work(&adapter->scan_work);

	return 0;



out:

	up(&zfcp_data.config_sema);

	return retval;

	if (!ret)

		flush_work(&adapter->scan_work);

	return ret;

}



/**
@@ -184,10 +192,13 @@ static int zfcp_ccw_set_offline(struct ccw_device *ccw_device) 


	down(&zfcp_data.config_sema);

	adapter = dev_get_drvdata(&ccw_device->dev);

	if (!adapter)

		goto out;



	zfcp_erp_adapter_shutdown(adapter, 0, "ccsoff1", NULL);

	zfcp_erp_wait(adapter);

	zfcp_erp_thread_kill(adapter);

	up(&zfcp_data.config_sema);

out:

	return 0;

}
@@ -244,6 +255,7 @@ static void zfcp_ccw_shutdown(struct ccw_device *cdev) 
	adapter = dev_get_drvdata(&cdev->dev);

	zfcp_erp_adapter_shutdown(adapter, 0, "ccshut1", NULL);

	zfcp_erp_wait(adapter);

	zfcp_erp_thread_kill(adapter);

	up(&zfcp_data.config_sema);

}

drivers/s390/scsi/zfcp_erp.c

+5 −0
Original line number Diff line number Diff line
@@ -150,6 +150,9 @@ static int zfcp_erp_required_act(int want, struct zfcp_adapter *adapter, 
		a_status = atomic_read(&adapter->status);

		if (a_status & ZFCP_STATUS_COMMON_ERP_INUSE)

			return 0;

		if (!(a_status & ZFCP_STATUS_COMMON_RUNNING) &&

		    !(a_status & ZFCP_STATUS_COMMON_OPEN))

			return 0; /* shutdown requested for closed adapter */

	}



	return need;
@@ -1349,6 +1352,8 @@ void zfcp_erp_thread_kill(struct zfcp_adapter *adapter) 
{

	kthread_stop(adapter->erp_thread);

	adapter->erp_thread = NULL;

	WARN_ON(!list_empty(&adapter->erp_ready_head));

	WARN_ON(!list_empty(&adapter->erp_running_head));

}



/**