Commit 4a0079bc authored by Dan Williams's avatar Dan Williams
Browse files

nvdimm: Replace lockdep_mutex with local lock classes 

In response to an attempt to expand dev->lockdep_mutex for device_lock()
validation [1], Peter points out [2] that the lockdep API already has
the ability to assign a dedicated lock class per subsystem device-type.

Use lockdep_set_class() to override the default device_lock()
'__lockdep_no_validate__' class for each NVDIMM subsystem device-type. This
enables lockdep to detect deadlocks and recursive locking within the
device-driver core and the subsystem.

Link: https://lore.kernel.org/r/164982968798.684294.15817853329823976469.stgit@dwillia2-desk3.amr.corp.intel.com [1]
Link: https://lore.kernel.org/r/Ylf0dewci8myLvoW@hirez.programming.kicks-ass.net

 [2]
Suggested-by: default avatarPeter Zijlstra <peterz@infradead.org>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: default avatarIra Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/165055520896.3745911.8021255583475547548.stgit@dwillia2-desk3.amr.corp.intel.com


Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent 38a34e10

drivers/nvdimm/btt_devs.c

+5 −2
Original line number Diff line number Diff line
@@ -178,6 +178,8 @@ bool is_nd_btt(struct device *dev) 
}

EXPORT_SYMBOL(is_nd_btt);



static struct lock_class_key nvdimm_btt_key;



static struct device *__nd_btt_create(struct nd_region *nd_region,

				      unsigned long lbasize, uuid_t *uuid,

				      struct nd_namespace_common *ndns)
@@ -205,6 +207,7 @@ static struct device *__nd_btt_create(struct nd_region *nd_region, 
	dev->parent = &nd_region->dev;

	dev->type = &nd_btt_device_type;

	device_initialize(&nd_btt->dev);

	lockdep_set_class(&nd_btt->dev.mutex, &nvdimm_btt_key);

	if (ndns && !__nd_attach_ndns(&nd_btt->dev, ndns, &nd_btt->ndns)) {

		dev_dbg(&ndns->dev, "failed, already claimed by %s\n",

				dev_name(ndns->claim));
@@ -225,7 +228,7 @@ struct device *nd_btt_create(struct nd_region *nd_region) 
{

	struct device *dev = __nd_btt_create(nd_region, 0, NULL, NULL);



	__nd_device_register(dev);

	nd_device_register(dev);

	return dev;

}
@@ -324,7 +327,7 @@ static int __nd_btt_probe(struct nd_btt *nd_btt, 
	if (!nd_btt->uuid)

		return -ENOMEM;



	__nd_device_register(&nd_btt->dev);

	nd_device_register(&nd_btt->dev);



	return 0;

}

drivers/nvdimm/bus.c

+7 −7
Original line number Diff line number Diff line
@@ -334,6 +334,8 @@ struct nvdimm_bus *nvdimm_to_bus(struct nvdimm *nvdimm) 
}

EXPORT_SYMBOL_GPL(nvdimm_to_bus);



static struct lock_class_key nvdimm_bus_key;



struct nvdimm_bus *nvdimm_bus_register(struct device *parent,

		struct nvdimm_bus_descriptor *nd_desc)

{
@@ -360,6 +362,7 @@ struct nvdimm_bus *nvdimm_bus_register(struct device *parent, 
	nvdimm_bus->dev.bus = &nvdimm_bus_type;

	nvdimm_bus->dev.of_node = nd_desc->of_node;

	device_initialize(&nvdimm_bus->dev);

	lockdep_set_class(&nvdimm_bus->dev.mutex, &nvdimm_bus_key);

	device_set_pm_not_required(&nvdimm_bus->dev);

	rc = dev_set_name(&nvdimm_bus->dev, "ndbus%d", nvdimm_bus->id);

	if (rc)
@@ -511,7 +514,7 @@ static void nd_async_device_unregister(void *d, async_cookie_t cookie) 
	put_device(dev);

}



void __nd_device_register(struct device *dev)

void nd_device_register(struct device *dev)

{

	if (!dev)

		return;
@@ -537,12 +540,6 @@ void __nd_device_register(struct device *dev) 
	async_schedule_dev_domain(nd_async_device_register, dev,

				  &nd_async_domain);

}



void nd_device_register(struct device *dev)

{

	device_initialize(dev);

	__nd_device_register(dev);

}

EXPORT_SYMBOL(nd_device_register);



void nd_device_unregister(struct device *dev, enum nd_async_mode mode)
@@ -724,6 +721,8 @@ static void ndctl_release(struct device *dev) 
	kfree(dev);

}



static struct lock_class_key nvdimm_ndctl_key;



int nvdimm_bus_create_ndctl(struct nvdimm_bus *nvdimm_bus)

{

	dev_t devt = MKDEV(nvdimm_bus_major, nvdimm_bus->id);
@@ -734,6 +733,7 @@ int nvdimm_bus_create_ndctl(struct nvdimm_bus *nvdimm_bus) 
	if (!dev)

		return -ENOMEM;

	device_initialize(dev);

	lockdep_set_class(&dev->mutex, &nvdimm_ndctl_key);

	device_set_pm_not_required(dev);

	dev->class = nd_class;

	dev->parent = &nvdimm_bus->dev;

drivers/nvdimm/dax_devs.c

+2 −2
Original line number Diff line number Diff line
@@ -80,7 +80,7 @@ struct device *nd_dax_create(struct nd_region *nd_region) 
	nd_dax = nd_dax_alloc(nd_region);

	if (nd_dax)

		dev = nd_pfn_devinit(&nd_dax->nd_pfn, NULL);

	__nd_device_register(dev);

	nd_device_register(dev);

	return dev;

}
@@ -119,7 +119,7 @@ int nd_dax_probe(struct device *dev, struct nd_namespace_common *ndns) 
		nd_detach_ndns(dax_dev, &nd_pfn->ndns);

		put_device(dax_dev);

	} else

		__nd_device_register(dax_dev);

		nd_device_register(dax_dev);



	return rc;

}

drivers/nvdimm/dimm_devs.c

+4 −0
Original line number Diff line number Diff line
@@ -570,6 +570,8 @@ bool is_nvdimm(struct device *dev) 
	return dev->type == &nvdimm_device_type;

}



static struct lock_class_key nvdimm_key;



struct nvdimm *__nvdimm_create(struct nvdimm_bus *nvdimm_bus,

		void *provider_data, const struct attribute_group **groups,

		unsigned long flags, unsigned long cmd_mask, int num_flush,
@@ -613,6 +615,8 @@ struct nvdimm *__nvdimm_create(struct nvdimm_bus *nvdimm_bus, 
	/* get security state and extended (master) state */

	nvdimm->sec.flags = nvdimm_security_flags(nvdimm, NVDIMM_USER);

	nvdimm->sec.ext_flags = nvdimm_security_flags(nvdimm, NVDIMM_MASTER);

	device_initialize(dev);

	lockdep_set_class(&dev->mutex, &nvdimm_key);

	nd_device_register(dev);



	return nvdimm;

drivers/nvdimm/namespace_devs.c

+9 −1
Original line number Diff line number Diff line
@@ -1830,6 +1830,8 @@ static struct device *nd_namespace_pmem_create(struct nd_region *nd_region) 
	return dev;

}



static struct lock_class_key nvdimm_namespace_key;



void nd_region_create_ns_seed(struct nd_region *nd_region)

{

	WARN_ON(!is_nvdimm_bus_locked(&nd_region->dev));
@@ -1845,9 +1847,13 @@ void nd_region_create_ns_seed(struct nd_region *nd_region) 
	 */

	if (!nd_region->ns_seed)

		dev_err(&nd_region->dev, "failed to create namespace\n");

	else

	else {

		device_initialize(nd_region->ns_seed);

		lockdep_set_class(&nd_region->ns_seed->mutex,

				  &nvdimm_namespace_key);

		nd_device_register(nd_region->ns_seed);

	}

}



void nd_region_create_dax_seed(struct nd_region *nd_region)

{
@@ -2200,6 +2206,8 @@ int nd_region_register_namespaces(struct nd_region *nd_region, int *err) 
		if (id < 0)

			break;

		dev_set_name(dev, "namespace%d.%d", nd_region->id, id);

		device_initialize(dev);

		lockdep_set_class(&dev->mutex, &nvdimm_namespace_key);

		nd_device_register(dev);

	}

	if (i)