From 143bb6bfe36d20618d8bf667915fe14d14b8ae2f Mon Sep 17 00:00:00 2001 From: Christof Schmitt Date: Tue, 18 Aug 2009 15:43:27 +0200 Subject: [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: Swen Schillig Signed-off-by: Christof Schmitt Signed-off-by: James Bottomley --- drivers/s390/scsi/zfcp_ccw.c | 74 +++++++++++++++++++++++++------------------- 1 file changed, 43 insertions(+), 31 deletions(-) (limited to 'drivers/s390/scsi/zfcp_ccw.c') diff --git a/drivers/s390/scsi/zfcp_ccw.c b/drivers/s390/scsi/zfcp_ccw.c index d9da5c42ccbe..82ae6ed7ef83 100644 --- a/drivers/s390/scsi/zfcp_ccw.c +++ b/drivers/s390/scsi/zfcp_ccw.c @@ -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) - goto out; + 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); +out: 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); } -- cgit v1.2.1