linux_dsm_epyc7002/drivers/s390/scsi/zfcp_ccw.c

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/*
* zfcp device driver
*
* Registration and callback for the s390 common I/O layer.
*
* Copyright IBM Corporation 2002, 2010
*/
#define KMSG_COMPONENT "zfcp"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
#include "zfcp_ext.h"
#include "zfcp_reqlist.h"
#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_activate(struct ccw_device *cdev)
{
struct zfcp_adapter *adapter = zfcp_ccw_adapter_by_cdev(cdev);
if (!adapter)
return 0;
zfcp_erp_set_adapter_status(adapter, ZFCP_STATUS_COMMON_RUNNING);
zfcp_erp_adapter_reopen(adapter, ZFCP_STATUS_COMMON_ERP_FAILED,
"ccresu2");
zfcp_erp_wait(adapter);
flush_work(&adapter->scan_work);
zfcp_ccw_adapter_put(adapter);
return 0;
}
static struct ccw_device_id zfcp_ccw_device_id[] = {
{ CCW_DEVICE_DEVTYPE(0x1731, 0x3, 0x1732, 0x3) },
{ CCW_DEVICE_DEVTYPE(0x1731, 0x3, 0x1732, ZFCP_MODEL_PRIV) },
{},
};
MODULE_DEVICE_TABLE(ccw, zfcp_ccw_device_id);
/**
* zfcp_ccw_priv_sch - check if subchannel is privileged
* @adapter: Adapter/Subchannel to check
*/
int zfcp_ccw_priv_sch(struct zfcp_adapter *adapter)
{
return adapter->ccw_device->id.dev_model == ZFCP_MODEL_PRIV;
}
/**
* zfcp_ccw_probe - probe function of zfcp driver
* @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 *cdev)
{
return 0;
}
/**
* zfcp_ccw_remove - remove function of zfcp driver
* @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 *cdev)
{
struct zfcp_adapter *adapter;
struct zfcp_port *port, *p;
struct zfcp_unit *unit, *u;
LIST_HEAD(unit_remove_lh);
LIST_HEAD(port_remove_lh);
ccw_device_set_offline(cdev);
[SCSI] zfcp: Fix lockdep warning when offlining device with offline chpid ======================================================= [ INFO: possible circular locking dependency detected ] 2.6.31-39.x.20090917-s390xdefault #1 ------------------------------------------------------- kslowcrw/83 is trying to acquire lock: (&adapter->scan_work){+.+.+.}, at: [<0000000000169c5c>] __cancel_work_timer+0x64/0x3d4 but task is already holding lock: (&zfcp_data.config_mutex){+.+.+.}, at: [<00000000004671ea>] zfcp_ccw_remove+0x66/0x384 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&zfcp_data.config_mutex){+.+.+.}: [<0000000000189962>] __lock_acquire+0xe26/0x1834 [<000000000018a4b6>] lock_acquire+0x146/0x178 [<000000000058cb5a>] mutex_lock_nested+0x82/0x3ec [<0000000000477170>] zfcp_fc_scan_ports+0x3ec/0x728 [<0000000000168e34>] worker_thread+0x278/0x3a8 [<000000000016ff08>] kthread+0x9c/0xa4 [<0000000000109ebe>] kernel_thread_starter+0x6/0xc [<0000000000109eb8>] kernel_thread_starter+0x0/0xc -> #0 (&adapter->scan_work){+.+.+.}: [<0000000000189e60>] __lock_acquire+0x1324/0x1834 [<000000000018a4b6>] lock_acquire+0x146/0x178 [<0000000000169c9a>] __cancel_work_timer+0xa2/0x3d4 [<0000000000465cb2>] zfcp_adapter_dequeue+0x32/0x14c [<00000000004673e4>] zfcp_ccw_remove+0x260/0x384 [<00000000004250f6>] ccw_device_remove+0x42/0x1ac [<00000000003cb6be>] __device_release_driver+0x9a/0x10c [<00000000003cb856>] device_release_driver+0x3a/0x4c [<00000000003ca94c>] bus_remove_device+0xcc/0x114 [<00000000003c8506>] device_del+0x162/0x21c [<0000000000425ff2>] ccw_device_unregister+0x5e/0x7c [<000000000042607e>] io_subchannel_remove+0x6e/0x9c [<000000000041ff9a>] css_remove+0x3e/0x7c [<00000000003cb6be>] __device_release_driver+0x9a/0x10c [<00000000003cb856>] device_release_driver+0x3a/0x4c [<00000000003ca94c>] bus_remove_device+0xcc/0x114 [<00000000003c8506>] device_del+0x162/0x21c [<00000000003c85e8>] device_unregister+0x28/0x38 [<0000000000420152>] css_sch_device_unregister+0x46/0x58 [<00000000004276a6>] io_subchannel_sch_event+0x28e/0x794 [<0000000000420442>] css_evaluate_known_subchannel+0x46/0xd0 [<0000000000420ebc>] slow_eval_known_fn+0x88/0xa0 [<00000000003caffa>] bus_for_each_dev+0x7e/0xd0 [<000000000042188c>] for_each_subchannel_staged+0x6c/0xd4 [<0000000000421a00>] css_slow_path_func+0x54/0xd8 [<0000000000168e34>] worker_thread+0x278/0x3a8 [<000000000016ff08>] kthread+0x9c/0xa4 [<0000000000109ebe>] kernel_thread_starter+0x6/0xc [<0000000000109eb8>] kernel_thread_starter+0x0/0xc cancel_work_sync is called while holding the config_mutex. But the work that is being cancelled or flushed also uses the config_mutex. Fix the resulting deadlock possibility by calling cancel_work_sync earlier without holding the mutex. The best place to do is is after offlining the device. No new port scan work will be scheduled for the offline device, so this is a safe place to call cancel_work_sync. Reviewed-by: Felix Beck <felix.beck@de.ibm.com> Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com> Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2009-09-24 15:23:24 +07:00
adapter = zfcp_ccw_adapter_by_cdev(cdev);
if (!adapter)
return;
write_lock_irq(&adapter->port_list_lock);
list_for_each_entry_safe(port, p, &adapter->port_list, list) {
write_lock(&port->unit_list_lock);
list_for_each_entry_safe(unit, u, &port->unit_list, list)
list_move(&unit->list, &unit_remove_lh);
write_unlock(&port->unit_list_lock);
list_move(&port->list, &port_remove_lh);
}
write_unlock_irq(&adapter->port_list_lock);
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->dev, &zfcp_sysfs_unit_attrs);
list_for_each_entry_safe(port, p, &port_remove_lh, list)
zfcp_device_unregister(&port->dev, &zfcp_sysfs_port_attrs);
zfcp_adapter_unregister(adapter);
}
/**
* zfcp_ccw_set_online - set_online function of zfcp driver
* @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
* 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 *cdev)
{
struct zfcp_adapter *adapter = zfcp_ccw_adapter_by_cdev(cdev);
if (!adapter) {
adapter = zfcp_adapter_enqueue(cdev);
if (IS_ERR(adapter)) {
dev_err(&cdev->dev,
"Setting up data structures for the "
"FCP adapter failed\n");
return PTR_ERR(adapter);
}
kref_get(&adapter->ref);
}
/* initialize request counter */
BUG_ON(!zfcp_reqlist_isempty(adapter->req_list));
adapter->req_no = 0;
zfcp_ccw_activate(cdev);
zfcp_ccw_adapter_put(adapter);
return 0;
}
/**
* zfcp_ccw_set_offline - set_offline function of zfcp driver
* @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 *cdev)
{
struct zfcp_adapter *adapter = zfcp_ccw_adapter_by_cdev(cdev);
if (!adapter)
return 0;
zfcp_erp_adapter_shutdown(adapter, 0, "ccsoff1");
zfcp_erp_wait(adapter);
zfcp_ccw_adapter_put(adapter);
return 0;
}
/**
* zfcp_ccw_notify - ccw notify function
* @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 *cdev, int event)
{
struct zfcp_adapter *adapter = zfcp_ccw_adapter_by_cdev(cdev);
if (!adapter)
return 1;
switch (event) {
case CIO_GONE:
dev_warn(&cdev->dev, "The FCP device has been detached\n");
zfcp_erp_adapter_shutdown(adapter, 0, "ccnoti1");
break;
case CIO_NO_PATH:
dev_warn(&cdev->dev,
"The CHPID for the FCP device is offline\n");
zfcp_erp_adapter_shutdown(adapter, 0, "ccnoti2");
break;
case CIO_OPER:
dev_info(&cdev->dev, "The FCP device is operational again\n");
zfcp_erp_set_adapter_status(adapter,
ZFCP_STATUS_COMMON_RUNNING);
zfcp_erp_adapter_reopen(adapter, ZFCP_STATUS_COMMON_ERP_FAILED,
"ccnoti4");
break;
case CIO_BOXED:
dev_warn(&cdev->dev, "The FCP device did not respond within "
"the specified time\n");
zfcp_erp_adapter_shutdown(adapter, 0, "ccnoti5");
break;
}
zfcp_ccw_adapter_put(adapter);
return 1;
}
/**
* zfcp_ccw_shutdown - handle shutdown from cio
* @cdev: device for adapter to shutdown.
*/
static void zfcp_ccw_shutdown(struct ccw_device *cdev)
{
struct zfcp_adapter *adapter = zfcp_ccw_adapter_by_cdev(cdev);
if (!adapter)
return;
zfcp_erp_adapter_shutdown(adapter, 0, "ccshut1");
zfcp_erp_wait(adapter);
zfcp_erp_thread_kill(adapter);
zfcp_ccw_adapter_put(adapter);
}
struct ccw_driver zfcp_ccw_driver = {
.driver = {
.owner = THIS_MODULE,
.name = "zfcp",
},
.ids = zfcp_ccw_device_id,
.probe = zfcp_ccw_probe,
.remove = zfcp_ccw_remove,
.set_online = zfcp_ccw_set_online,
.set_offline = zfcp_ccw_set_offline,
.notify = zfcp_ccw_notify,
.shutdown = zfcp_ccw_shutdown,
.freeze = zfcp_ccw_set_offline,
.thaw = zfcp_ccw_activate,
.restore = zfcp_ccw_activate,
};