From 730926c3b0998943654019f00296cf8e3b02277e Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Sun, 16 Jul 2017 13:51:53 -0700 Subject: device-dax: Add /sys/class/dax backwards compatibility On the expectation that some environments may not upgrade libdaxctl (userspace component that depends on the /sys/class/dax hierarchy), provide a default / legacy dax_pmem_compat driver. The dax_pmem_compat driver implements the original /sys/class/dax sysfs layout rather than /sys/bus/dax. When userspace is upgraded it can blacklist this module and switch to the dax_pmem driver going forward. CONFIG_DEV_DAX_PMEM_COMPAT and supporting code will be deleted according to the dax_pmem entry in Documentation/ABI/obsolete/. Signed-off-by: Dan Williams --- drivers/dax/bus.c | 29 ++++++++++++++++++++++++----- 1 file changed, 24 insertions(+), 5 deletions(-) (limited to 'drivers/dax/bus.c') diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c index 17af6fbc3be5..568168500217 100644 --- a/drivers/dax/bus.c +++ b/drivers/dax/bus.c @@ -9,6 +9,8 @@ #include "dax-private.h" #include "bus.h" +static struct class *dax_class; + static DEFINE_MUTEX(dax_bus_lock); #define DAX_NAME_LEN 30 @@ -310,8 +312,8 @@ static void unregister_dev_dax(void *dev) put_device(dev); } -struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region, int id, - struct dev_pagemap *pgmap) +struct dev_dax *__devm_create_dev_dax(struct dax_region *dax_region, int id, + struct dev_pagemap *pgmap, enum dev_dax_subsys subsys) { struct device *parent = dax_region->dev; struct dax_device *dax_dev; @@ -350,7 +352,10 @@ struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region, int id, inode = dax_inode(dax_dev); dev->devt = inode->i_rdev; - dev->bus = &dax_bus_type; + if (subsys == DEV_DAX_BUS) + dev->bus = &dax_bus_type; + else + dev->class = dax_class; dev->parent = parent; dev->groups = dax_attribute_groups; dev->release = dev_dax_release; @@ -374,7 +379,7 @@ struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region, int id, return ERR_PTR(rc); } -EXPORT_SYMBOL_GPL(devm_create_dev_dax); +EXPORT_SYMBOL_GPL(__devm_create_dev_dax); static int match_always_count; @@ -407,6 +412,7 @@ EXPORT_SYMBOL_GPL(__dax_driver_register); void dax_driver_unregister(struct dax_device_driver *dax_drv) { + struct device_driver *drv = &dax_drv->drv; struct dax_id *dax_id, *_id; mutex_lock(&dax_bus_lock); @@ -416,15 +422,28 @@ void dax_driver_unregister(struct dax_device_driver *dax_drv) kfree(dax_id); } mutex_unlock(&dax_bus_lock); + driver_unregister(drv); } EXPORT_SYMBOL_GPL(dax_driver_unregister); int __init dax_bus_init(void) { - return bus_register(&dax_bus_type); + int rc; + + if (IS_ENABLED(CONFIG_DEV_DAX_PMEM_COMPAT)) { + dax_class = class_create(THIS_MODULE, "dax"); + if (IS_ERR(dax_class)) + return PTR_ERR(dax_class); + } + + rc = bus_register(&dax_bus_type); + if (rc) + class_destroy(dax_class); + return rc; } void __exit dax_bus_exit(void) { bus_unregister(&dax_bus_type); + class_destroy(dax_class); } -- cgit v1.2.3