[SCSI] zfcp: Remove global config_mutex
The global config_mutex was required for the serialization of a
configuration change within the zfcp driver. This global locking is
now obsolete and can be removed. The requirement of serializing the
access to a zfcp_adapter reference via a ccw_device is realized wth a
static spinlock.
Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
diff --git a/drivers/s390/scsi/zfcp_ccw.c b/drivers/s390/scsi/zfcp_ccw.c
index c89dbe2..2433eac 100644
--- a/drivers/s390/scsi/zfcp_ccw.c
+++ b/drivers/s390/scsi/zfcp_ccw.c
@@ -13,20 +13,42 @@
#define ZFCP_MODEL_PRIV 0x4
+static DEFINE_SPINLOCK(zfcp_ccw_adapter_ref_lock);
+
+struct zfcp_adapter *zfcp_ccw_adapter_by_cdev(struct ccw_device *cdev)
+{
+ struct zfcp_adapter *adapter;
+ unsigned long flags;
+
+ spin_lock_irqsave(&zfcp_ccw_adapter_ref_lock, flags);
+ adapter = dev_get_drvdata(&cdev->dev);
+ if (adapter)
+ kref_get(&adapter->ref);
+ spin_unlock_irqrestore(&zfcp_ccw_adapter_ref_lock, flags);
+ return adapter;
+}
+
+void zfcp_ccw_adapter_put(struct zfcp_adapter *adapter)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&zfcp_ccw_adapter_ref_lock, flags);
+ kref_put(&adapter->ref, zfcp_adapter_release);
+ spin_unlock_irqrestore(&zfcp_ccw_adapter_ref_lock, flags);
+}
+
static int zfcp_ccw_suspend(struct ccw_device *cdev)
{
- struct zfcp_adapter *adapter = dev_get_drvdata(&cdev->dev);
+ struct zfcp_adapter *adapter = zfcp_ccw_adapter_by_cdev(cdev);
if (!adapter)
return 0;
- mutex_lock(&zfcp_data.config_mutex);
-
zfcp_erp_adapter_shutdown(adapter, 0, "ccsusp1", NULL);
zfcp_erp_wait(adapter);
- mutex_unlock(&zfcp_data.config_mutex);
+ zfcp_ccw_adapter_put(adapter);
return 0;
}
@@ -34,7 +56,7 @@
static int zfcp_ccw_activate(struct ccw_device *cdev)
{
- struct zfcp_adapter *adapter = dev_get_drvdata(&cdev->dev);
+ struct zfcp_adapter *adapter = zfcp_ccw_adapter_by_cdev(cdev);
if (!adapter)
return 0;
@@ -46,6 +68,8 @@
zfcp_erp_wait(adapter);
flush_work(&adapter->scan_work);
+ zfcp_ccw_adapter_put(adapter);
+
return 0;
}
@@ -67,28 +91,28 @@
/**
* zfcp_ccw_probe - probe function of zfcp driver
- * @ccw_device: pointer to belonging ccw device
+ * @cdev: pointer to belonging ccw device
*
* 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)
+static int zfcp_ccw_probe(struct ccw_device *cdev)
{
return 0;
}
/**
* zfcp_ccw_remove - remove function of zfcp driver
- * @ccw_device: pointer to belonging ccw device
+ * @cdev: pointer to belonging ccw device
*
* This function gets called by the common i/o layer and removes an adapter
* from the system. Task of this function is to get rid of all units and
* ports that belong to this adapter. And in addition all resources of this
* adapter will be freed too.
*/
-static void zfcp_ccw_remove(struct ccw_device *ccw_device)
+static void zfcp_ccw_remove(struct ccw_device *cdev)
{
struct zfcp_adapter *adapter;
struct zfcp_port *port, *p;
@@ -96,22 +120,12 @@
LIST_HEAD(unit_remove_lh);
LIST_HEAD(port_remove_lh);
- ccw_device_set_offline(ccw_device);
+ ccw_device_set_offline(cdev);
- mutex_lock(&zfcp_data.config_mutex);
- adapter = dev_get_drvdata(&ccw_device->dev);
- mutex_unlock(&zfcp_data.config_mutex);
-
+ adapter = zfcp_ccw_adapter_by_cdev(cdev);
if (!adapter)
return;
- cancel_work_sync(&adapter->scan_work);
-
- mutex_lock(&zfcp_data.config_mutex);
-
- /* this also removes the scsi devices, so call it first */
- zfcp_adapter_scsi_unregister(adapter);
-
write_lock_irq(&adapter->port_list_lock);
list_for_each_entry_safe(port, p, &adapter->port_list, list) {
write_lock(&port->unit_list_lock);
@@ -126,7 +140,7 @@
}
atomic_set_mask(ZFCP_STATUS_COMMON_REMOVE, &adapter->status);
write_unlock_irq(&adapter->port_list_lock);
- mutex_unlock(&zfcp_data.config_mutex);
+ zfcp_ccw_adapter_put(adapter); /* put from zfcp_ccw_adapter_by_cdev */
list_for_each_entry_safe(unit, u, &unit_remove_lh, list)
zfcp_device_unregister(&unit->sysfs_device,
@@ -136,12 +150,12 @@
zfcp_device_unregister(&port->sysfs_device,
&zfcp_sysfs_port_attrs);
- kref_put(&adapter->ref, zfcp_adapter_release);
+ zfcp_adapter_unregister(adapter);
}
/**
* zfcp_ccw_set_online - set_online function of zfcp driver
- * @ccw_device: pointer to belonging ccw device
+ * @cdev: pointer to belonging ccw device
*
* This function gets called by the common i/o layer and sets an
* adapter into state online. The first call will allocate all
@@ -152,23 +166,20 @@
* 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)
+static int zfcp_ccw_set_online(struct ccw_device *cdev)
{
- struct zfcp_adapter *adapter;
- int ret = 0;
-
- mutex_lock(&zfcp_data.config_mutex);
- adapter = dev_get_drvdata(&ccw_device->dev);
+ struct zfcp_adapter *adapter = zfcp_ccw_adapter_by_cdev(cdev);
if (!adapter) {
- ret = zfcp_adapter_enqueue(ccw_device);
- if (ret) {
- dev_err(&ccw_device->dev,
+ adapter = zfcp_adapter_enqueue(cdev);
+
+ if (IS_ERR(adapter)) {
+ dev_err(&cdev->dev,
"Setting up data structures for the "
"FCP adapter failed\n");
- goto out;
+ return PTR_ERR(adapter);
}
- adapter = dev_get_drvdata(&ccw_device->dev);
+ kref_get(&adapter->ref);
}
/* initialize request counter */
@@ -180,58 +191,61 @@
zfcp_erp_adapter_reopen(adapter, ZFCP_STATUS_COMMON_ERP_FAILED,
"ccsonl2", NULL);
zfcp_erp_wait(adapter);
-out:
- mutex_unlock(&zfcp_data.config_mutex);
- if (!ret)
- flush_work(&adapter->scan_work);
- return ret;
+
+ flush_work(&adapter->scan_work);
+
+ zfcp_ccw_adapter_put(adapter);
+ return 0;
}
/**
* zfcp_ccw_set_offline - set_offline function of zfcp driver
- * @ccw_device: pointer to belonging ccw device
+ * @cdev: pointer to belonging ccw device
*
* This function gets called by the common i/o layer and sets an adapter
* into state offline.
*/
-static int zfcp_ccw_set_offline(struct ccw_device *ccw_device)
+static int zfcp_ccw_set_offline(struct ccw_device *cdev)
{
- struct zfcp_adapter *adapter;
+ struct zfcp_adapter *adapter = zfcp_ccw_adapter_by_cdev(cdev);
- mutex_lock(&zfcp_data.config_mutex);
- adapter = dev_get_drvdata(&ccw_device->dev);
+ if (!adapter)
+ return 0;
+
zfcp_erp_adapter_shutdown(adapter, 0, "ccsoff1", NULL);
zfcp_erp_wait(adapter);
- mutex_unlock(&zfcp_data.config_mutex);
+
+ zfcp_ccw_adapter_put(adapter);
return 0;
}
/**
* zfcp_ccw_notify - ccw notify function
- * @ccw_device: pointer to belonging ccw device
+ * @cdev: pointer to belonging ccw device
* @event: indicates if adapter was detached or attached
*
* This function gets called by the common i/o layer if an adapter has gone
* or reappeared.
*/
-static int zfcp_ccw_notify(struct ccw_device *ccw_device, int event)
+static int zfcp_ccw_notify(struct ccw_device *cdev, int event)
{
- struct zfcp_adapter *adapter = dev_get_drvdata(&ccw_device->dev);
+ struct zfcp_adapter *adapter = zfcp_ccw_adapter_by_cdev(cdev);
+
+ if (!adapter)
+ return 1;
switch (event) {
case CIO_GONE:
- dev_warn(&adapter->ccw_device->dev,
- "The FCP device has been detached\n");
+ dev_warn(&cdev->dev, "The FCP device has been detached\n");
zfcp_erp_adapter_shutdown(adapter, 0, "ccnoti1", NULL);
break;
case CIO_NO_PATH:
- dev_warn(&adapter->ccw_device->dev,
+ dev_warn(&cdev->dev,
"The CHPID for the FCP device is offline\n");
zfcp_erp_adapter_shutdown(adapter, 0, "ccnoti2", NULL);
break;
case CIO_OPER:
- dev_info(&adapter->ccw_device->dev,
- "The FCP device is operational again\n");
+ dev_info(&cdev->dev, "The FCP device is operational again\n");
zfcp_erp_modify_adapter_status(adapter, "ccnoti3", NULL,
ZFCP_STATUS_COMMON_RUNNING,
ZFCP_SET);
@@ -239,11 +253,13 @@
"ccnoti4", NULL);
break;
case CIO_BOXED:
- dev_warn(&adapter->ccw_device->dev, "The FCP device "
- "did not respond within the specified time\n");
+ dev_warn(&cdev->dev, "The FCP device did not respond within "
+ "the specified time\n");
zfcp_erp_adapter_shutdown(adapter, 0, "ccnoti5", NULL);
break;
}
+
+ zfcp_ccw_adapter_put(adapter);
return 1;
}
@@ -253,18 +269,16 @@
*/
static void zfcp_ccw_shutdown(struct ccw_device *cdev)
{
- struct zfcp_adapter *adapter;
+ struct zfcp_adapter *adapter = zfcp_ccw_adapter_by_cdev(cdev);
- mutex_lock(&zfcp_data.config_mutex);
- adapter = dev_get_drvdata(&cdev->dev);
if (!adapter)
- goto out;
+ return;
zfcp_erp_adapter_shutdown(adapter, 0, "ccshut1", NULL);
zfcp_erp_wait(adapter);
zfcp_erp_thread_kill(adapter);
-out:
- mutex_unlock(&zfcp_data.config_mutex);
+
+ zfcp_ccw_adapter_put(adapter);
}
struct ccw_driver zfcp_ccw_driver = {