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Commit 18515942 authored by Dan Williams's avatar Dan Williams
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libnvdimm: register nvdimm_bus devices with an nd_bus driver 

A recent effort to add a new nvdimm bus provider attribute highlighted a
race between interrogating nvdimm_bus->nd_desc and nvdimm_bus tear down.
The typical way to handle these races is to take the device_lock() in
the attribute method and validate that the device is still active.  In
order for a device to be 'active' it needs to be associated with a
driver.  So, we create the small boilerplate for a driver and register
nvdimm_bus devices on the 'nvdimm_bus_type' bus.

A result of this change is that ndbusX devices now appear under
/sys/bus/nd/devices.  In fact this makes /sys/class/nd somewhat
redundant, but removing that will need to take a long deprecation period
given its use by ndctl binaries in the field.

This change naturally pulls code from drivers/nvdimm/core.c to
drivers/nvdimm/bus.c, so it is a nice code organization clean-up as
well.

Cc: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent 5bf0b6e1
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Showing with 181 additions and 134 deletions
drivers/nvdimm/bus.c
View file @ 18515942
......@@ -31,6 +31,7 @@
int nvdimm_major;
static int nvdimm_bus_major;
static struct class *nd_class;
static DEFINE_IDA(nd_ida);
static int to_nd_device_type(struct device *dev)
{
......@@ -60,13 +61,6 @@ static int nvdimm_bus_uevent(struct device *dev, struct kobj_uevent_env *env)
to_nd_device_type(dev));
}
static int nvdimm_bus_match(struct device *dev, struct device_driver *drv)
{
struct nd_device_driver *nd_drv = to_nd_device_driver(drv);
return !!test_bit(to_nd_device_type(dev), &nd_drv->type);
}
static struct module *to_bus_provider(struct device *dev)
{
/* pin bus providers while regions are enabled */
......@@ -223,6 +217,8 @@ long nvdimm_clear_poison(struct device *dev, phys_addr_t phys,
}
EXPORT_SYMBOL_GPL(nvdimm_clear_poison);
static int nvdimm_bus_match(struct device *dev, struct device_driver *drv);
static struct bus_type nvdimm_bus_type = {
.name = "nd",
.uevent = nvdimm_bus_uevent,
......@@ -232,6 +228,176 @@ static struct bus_type nvdimm_bus_type = {
.shutdown = nvdimm_bus_shutdown,
};
static void nvdimm_bus_release(struct device *dev)
{
struct nvdimm_bus *nvdimm_bus;
nvdimm_bus = container_of(dev, struct nvdimm_bus, dev);
ida_simple_remove(&nd_ida, nvdimm_bus->id);
kfree(nvdimm_bus);
}
static bool is_nvdimm_bus(struct device *dev)
{
return dev->release == nvdimm_bus_release;
}
struct nvdimm_bus *walk_to_nvdimm_bus(struct device *nd_dev)
{
struct device *dev;
for (dev = nd_dev; dev; dev = dev->parent)
if (is_nvdimm_bus(dev))
break;
dev_WARN_ONCE(nd_dev, !dev, "invalid dev, not on nd bus\n");
if (dev)
return to_nvdimm_bus(dev);
return NULL;
}
struct nvdimm_bus *to_nvdimm_bus(struct device *dev)
{
struct nvdimm_bus *nvdimm_bus;
nvdimm_bus = container_of(dev, struct nvdimm_bus, dev);
WARN_ON(!is_nvdimm_bus(dev));
return nvdimm_bus;
}
EXPORT_SYMBOL_GPL(to_nvdimm_bus);
struct nvdimm_bus *nvdimm_bus_register(struct device *parent,
struct nvdimm_bus_descriptor *nd_desc)
{
struct nvdimm_bus *nvdimm_bus;
int rc;
nvdimm_bus = kzalloc(sizeof(*nvdimm_bus), GFP_KERNEL);
if (!nvdimm_bus)
return NULL;
INIT_LIST_HEAD(&nvdimm_bus->list);
INIT_LIST_HEAD(&nvdimm_bus->mapping_list);
INIT_LIST_HEAD(&nvdimm_bus->poison_list);
init_waitqueue_head(&nvdimm_bus->probe_wait);
nvdimm_bus->id = ida_simple_get(&nd_ida, 0, 0, GFP_KERNEL);
mutex_init(&nvdimm_bus->reconfig_mutex);
if (nvdimm_bus->id < 0) {
kfree(nvdimm_bus);
return NULL;
}
nvdimm_bus->nd_desc = nd_desc;
nvdimm_bus->dev.parent = parent;
nvdimm_bus->dev.release = nvdimm_bus_release;
nvdimm_bus->dev.groups = nd_desc->attr_groups;
nvdimm_bus->dev.bus = &nvdimm_bus_type;
dev_set_name(&nvdimm_bus->dev, "ndbus%d", nvdimm_bus->id);
rc = device_register(&nvdimm_bus->dev);
if (rc) {
dev_dbg(&nvdimm_bus->dev, "registration failed: %d\n", rc);
goto err;
}
return nvdimm_bus;
err:
put_device(&nvdimm_bus->dev);
return NULL;
}
EXPORT_SYMBOL_GPL(nvdimm_bus_register);
void nvdimm_bus_unregister(struct nvdimm_bus *nvdimm_bus)
{
if (!nvdimm_bus)
return;
device_unregister(&nvdimm_bus->dev);
}
EXPORT_SYMBOL_GPL(nvdimm_bus_unregister);
static int child_unregister(struct device *dev, void *data)
{
/*
* the singular ndctl class device per bus needs to be
* "device_destroy"ed, so skip it here
*
* i.e. remove classless children
*/
if (dev->class)
/* pass */;
else
nd_device_unregister(dev, ND_SYNC);
return 0;
}
static void free_poison_list(struct list_head *poison_list)
{
struct nd_poison *pl, *next;
list_for_each_entry_safe(pl, next, poison_list, list) {
list_del(&pl->list);
kfree(pl);
}
list_del_init(poison_list);
}
static int nd_bus_remove(struct device *dev)
{
struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
mutex_lock(&nvdimm_bus_list_mutex);
list_del_init(&nvdimm_bus->list);
mutex_unlock(&nvdimm_bus_list_mutex);
nd_synchronize();
device_for_each_child(&nvdimm_bus->dev, NULL, child_unregister);
nvdimm_bus_lock(&nvdimm_bus->dev);
free_poison_list(&nvdimm_bus->poison_list);
nvdimm_bus_unlock(&nvdimm_bus->dev);
nvdimm_bus_destroy_ndctl(nvdimm_bus);
return 0;
}
static int nd_bus_probe(struct device *dev)
{
struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
int rc;
rc = nvdimm_bus_create_ndctl(nvdimm_bus);
if (rc)
return rc;
mutex_lock(&nvdimm_bus_list_mutex);
list_add_tail(&nvdimm_bus->list, &nvdimm_bus_list);
mutex_unlock(&nvdimm_bus_list_mutex);
/* enable bus provider attributes to look up their local context */
dev_set_drvdata(dev, nvdimm_bus->nd_desc);
return 0;
}
static struct nd_device_driver nd_bus_driver = {
.probe = nd_bus_probe,
.remove = nd_bus_remove,
.drv = {
.name = "nd_bus",
.suppress_bind_attrs = true,
.bus = &nvdimm_bus_type,
.owner = THIS_MODULE,
.mod_name = KBUILD_MODNAME,
},
};
static int nvdimm_bus_match(struct device *dev, struct device_driver *drv)
{
struct nd_device_driver *nd_drv = to_nd_device_driver(drv);
if (is_nvdimm_bus(dev) && nd_drv == &nd_bus_driver)
return true;
return !!test_bit(to_nd_device_type(dev), &nd_drv->type);
}
static ASYNC_DOMAIN_EXCLUSIVE(nd_async_domain);
void nd_synchronize(void)
......@@ -864,8 +1030,14 @@ int __init nvdimm_bus_init(void)
goto err_class;
}
rc = driver_register(&nd_bus_driver.drv);
if (rc)
goto err_nd_bus;
return 0;
err_nd_bus:
class_destroy(nd_class);
err_class:
unregister_chrdev(nvdimm_major, "dimmctl");
err_dimm_chrdev:
......@@ -878,8 +1050,10 @@ int __init nvdimm_bus_init(void)
void nvdimm_bus_exit(void)
{
driver_unregister(&nd_bus_driver.drv);
class_destroy(nd_class);
unregister_chrdev(nvdimm_bus_major, "ndctl");
unregister_chrdev(nvdimm_major, "dimmctl");
bus_unregister(&nvdimm_bus_type);
ida_destroy(&nd_ida);
}
drivers/nvdimm/core.c
View file @ 18515942
......@@ -26,7 +26,6 @@
LIST_HEAD(nvdimm_bus_list);
DEFINE_MUTEX(nvdimm_bus_list_mutex);
static DEFINE_IDA(nd_ida);
void nvdimm_bus_lock(struct device *dev)
{
......@@ -195,25 +194,6 @@ u64 nd_fletcher64(void *addr, size_t len, bool le)
}
EXPORT_SYMBOL_GPL(nd_fletcher64);
static void nvdimm_bus_release(struct device *dev)
{
struct nvdimm_bus *nvdimm_bus;
nvdimm_bus = container_of(dev, struct nvdimm_bus, dev);
ida_simple_remove(&nd_ida, nvdimm_bus->id);
kfree(nvdimm_bus);
}
struct nvdimm_bus *to_nvdimm_bus(struct device *dev)
{
struct nvdimm_bus *nvdimm_bus;
nvdimm_bus = container_of(dev, struct nvdimm_bus, dev);
WARN_ON(nvdimm_bus->dev.release != nvdimm_bus_release);
return nvdimm_bus;
}
EXPORT_SYMBOL_GPL(to_nvdimm_bus);
struct nvdimm_bus_descriptor *to_nd_desc(struct nvdimm_bus *nvdimm_bus)
{
/* struct nvdimm_bus definition is private to libnvdimm */
......@@ -221,19 +201,6 @@ struct nvdimm_bus_descriptor *to_nd_desc(struct nvdimm_bus *nvdimm_bus)
}
EXPORT_SYMBOL_GPL(to_nd_desc);
struct nvdimm_bus *walk_to_nvdimm_bus(struct device *nd_dev)
{
struct device *dev;
for (dev = nd_dev; dev; dev = dev->parent)
if (dev->release == nvdimm_bus_release)
break;
dev_WARN_ONCE(nd_dev, !dev, "invalid dev, not on nd bus\n");
if (dev)
return to_nvdimm_bus(dev);
return NULL;
}
static bool is_uuid_sep(char sep)
{
if (sep == '\n' || sep == '-' || sep == ':' || sep == '\0')
......@@ -447,51 +414,6 @@ struct attribute_group nvdimm_bus_attribute_group = {
};
EXPORT_SYMBOL_GPL(nvdimm_bus_attribute_group);
struct nvdimm_bus *nvdimm_bus_register(struct device *parent,
struct nvdimm_bus_descriptor *nd_desc)
{
struct nvdimm_bus *nvdimm_bus;
int rc;
nvdimm_bus = kzalloc(sizeof(*nvdimm_bus), GFP_KERNEL);
if (!nvdimm_bus)
return NULL;
INIT_LIST_HEAD(&nvdimm_bus->list);
INIT_LIST_HEAD(&nvdimm_bus->mapping_list);
INIT_LIST_HEAD(&nvdimm_bus->poison_list);
init_waitqueue_head(&nvdimm_bus->probe_wait);
nvdimm_bus->id = ida_simple_get(&nd_ida, 0, 0, GFP_KERNEL);
mutex_init(&nvdimm_bus->reconfig_mutex);
if (nvdimm_bus->id < 0) {
kfree(nvdimm_bus);
return NULL;
}
nvdimm_bus->nd_desc = nd_desc;
nvdimm_bus->dev.parent = parent;
nvdimm_bus->dev.release = nvdimm_bus_release;
nvdimm_bus->dev.groups = nd_desc->attr_groups;
dev_set_name(&nvdimm_bus->dev, "ndbus%d", nvdimm_bus->id);
rc = device_register(&nvdimm_bus->dev);
if (rc) {
dev_dbg(&nvdimm_bus->dev, "registration failed: %d\n", rc);
goto err;
}
rc = nvdimm_bus_create_ndctl(nvdimm_bus);
if (rc)
goto err;
mutex_lock(&nvdimm_bus_list_mutex);
list_add_tail(&nvdimm_bus->list, &nvdimm_bus_list);
mutex_unlock(&nvdimm_bus_list_mutex);
return nvdimm_bus;
err:
put_device(&nvdimm_bus->dev);
return NULL;
}
EXPORT_SYMBOL_GPL(nvdimm_bus_register);
static void set_badblock(struct badblocks *bb, sector_t s, int num)
{
dev_dbg(bb->dev, "Found a poison range (0x%llx, 0x%llx)\n",
......@@ -667,54 +589,6 @@ int nvdimm_bus_add_poison(struct nvdimm_bus *nvdimm_bus, u64 addr, u64 length)
}
EXPORT_SYMBOL_GPL(nvdimm_bus_add_poison);
static void free_poison_list(struct list_head *poison_list)
{
struct nd_poison *pl, *next;
list_for_each_entry_safe(pl, next, poison_list, list) {
list_del(&pl->list);
kfree(pl);
}
list_del_init(poison_list);
}
static int child_unregister(struct device *dev, void *data)
{
/*
* the singular ndctl class device per bus needs to be
* "device_destroy"ed, so skip it here
*
* i.e. remove classless children
*/
if (dev->class)
/* pass */;
else
nd_device_unregister(dev, ND_SYNC);
return 0;
}
void nvdimm_bus_unregister(struct nvdimm_bus *nvdimm_bus)
{
if (!nvdimm_bus)
return;
mutex_lock(&nvdimm_bus_list_mutex);
list_del_init(&nvdimm_bus->list);
mutex_unlock(&nvdimm_bus_list_mutex);
nd_synchronize();
device_for_each_child(&nvdimm_bus->dev, NULL, child_unregister);
nvdimm_bus_lock(&nvdimm_bus->dev);
free_poison_list(&nvdimm_bus->poison_list);
nvdimm_bus_unlock(&nvdimm_bus->dev);
nvdimm_bus_destroy_ndctl(nvdimm_bus);
device_unregister(&nvdimm_bus->dev);
}
EXPORT_SYMBOL_GPL(nvdimm_bus_unregister);
#ifdef CONFIG_BLK_DEV_INTEGRITY
int nd_integrity_init(struct gendisk *disk, unsigned long meta_size)
{
......@@ -773,7 +647,6 @@ static __exit void libnvdimm_exit(void)
nvdimm_bus_exit();
nd_region_devs_exit();
nvdimm_devs_exit();
ida_destroy(&nd_ida);
}
MODULE_LICENSE("GPL v2");
......
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