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
Link: https://lore.kernel.org/r/Ylf0dewci8myLvoW@hirez.programming.kicks-ass.net
Suggested-by: Peter 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: Ira Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/165055520896.3745911.8021255583475547548.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

diff --git a/drivers/nvdimm/btt_devs.c b/drivers/nvdimm/btt_devs.c
index e5a5852..1208217 100644 (file)
--- a/drivers/nvdimm/btt_devs.c
+++ b/drivers/nvdimm/btt_devs.c
@@ -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;
 }

diff --git a/drivers/nvdimm/bus.c b/drivers/nvdimm/bus.c
index 7b0d144..85ffa04 100644 (file)
--- a/drivers/nvdimm/bus.c
+++ b/drivers/nvdimm/bus.c
@@ -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;

diff --git a/drivers/nvdimm/dax_devs.c b/drivers/nvdimm/dax_devs.c
index 9996507..7f4a9d2 100644 (file)
--- a/drivers/nvdimm/dax_devs.c
+++ b/drivers/nvdimm/dax_devs.c
@@ -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;
 }

diff --git a/drivers/nvdimm/dimm_devs.c b/drivers/nvdimm/dimm_devs.c
index ee507ee..27b8f8c 100644 (file)
--- a/drivers/nvdimm/dimm_devs.c
+++ b/drivers/nvdimm/dimm_devs.c
@@ -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;

diff --git a/drivers/nvdimm/namespace_devs.c b/drivers/nvdimm/namespace_devs.c
index 62b83b2..5197a81 100644 (file)
--- a/drivers/nvdimm/namespace_devs.c
+++ b/drivers/nvdimm/namespace_devs.c
@@ -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));
@@ -1845,8 +1847,12 @@ 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)

diff --git a/drivers/nvdimm/nd-core.h b/drivers/nvdimm/nd-core.h
index 448f9dc..99b0410 100644 (file)
--- a/drivers/nvdimm/nd-core.h
+++ b/drivers/nvdimm/nd-core.h
@@ -106,7 +106,7 @@ void nd_region_create_dax_seed(struct nd_region *nd_region);
 int nvdimm_bus_create_ndctl(struct nvdimm_bus *nvdimm_bus);
 void nvdimm_bus_destroy_ndctl(struct nvdimm_bus *nvdimm_bus);
 void nd_synchronize(void);
-void __nd_device_register(struct device *dev);
+void nd_device_register(struct device *dev);
 struct nd_label_id;
 char *nd_label_gen_id(struct nd_label_id *label_id, const uuid_t *uuid,
                      u32 flags);

diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c
index c31e184..0cd396d 100644 (file)
--- a/drivers/nvdimm/pfn_devs.c
+++ b/drivers/nvdimm/pfn_devs.c
@@ -291,6 +291,8 @@ bool is_nd_pfn(struct device *dev)
 }
 EXPORT_SYMBOL(is_nd_pfn);
 
+static struct lock_class_key nvdimm_pfn_key;
+
 struct device *nd_pfn_devinit(struct nd_pfn *nd_pfn,
                struct nd_namespace_common *ndns)
 {
@@ -303,6 +305,7 @@ struct device *nd_pfn_devinit(struct nd_pfn *nd_pfn,
        nd_pfn->align = nd_pfn_default_alignment();
        dev = &nd_pfn->dev;
        device_initialize(&nd_pfn->dev);
+       lockdep_set_class(&nd_pfn->dev.mutex, &nvdimm_pfn_key);
        if (ndns && !__nd_attach_ndns(&nd_pfn->dev, ndns, &nd_pfn->ndns)) {
                dev_dbg(&ndns->dev, "failed, already claimed by %s\n",
                                dev_name(ndns->claim));
@@ -346,7 +349,7 @@ struct device *nd_pfn_create(struct nd_region *nd_region)
        nd_pfn = nd_pfn_alloc(nd_region);
        dev = nd_pfn_devinit(nd_pfn, NULL);
 
-       __nd_device_register(dev);
+       nd_device_register(dev);
        return dev;
 }
 
@@ -643,7 +646,7 @@ int nd_pfn_probe(struct device *dev, struct nd_namespace_common *ndns)
                nd_detach_ndns(pfn_dev, &nd_pfn->ndns);
                put_device(pfn_dev);
        } else
-               __nd_device_register(pfn_dev);
+               nd_device_register(pfn_dev);
 
        return rc;
 }

diff --git a/drivers/nvdimm/region_devs.c b/drivers/nvdimm/region_devs.c
index 0cb274c..8650e8d 100644 (file)
--- a/drivers/nvdimm/region_devs.c
+++ b/drivers/nvdimm/region_devs.c
@@ -949,6 +949,8 @@ static unsigned long default_align(struct nd_region *nd_region)
        return align;
 }
 
+static struct lock_class_key nvdimm_region_key;
+
 static struct nd_region *nd_region_create(struct nvdimm_bus *nvdimm_bus,
                struct nd_region_desc *ndr_desc,
                const struct device_type *dev_type, const char *caller)
@@ -1035,6 +1037,8 @@ static struct nd_region *nd_region_create(struct nvdimm_bus *nvdimm_bus,
        else
                nd_region->flush = NULL;
 
+       device_initialize(dev);
+       lockdep_set_class(&dev->mutex, &nvdimm_region_key);
        nd_device_register(dev);
 
        return nd_region;