diff --git a/drivers/dax/dax.c b/drivers/dax/dax.c index ef93aa84622b..5e8302d3a89c 100644 --- a/drivers/dax/dax.c +++ b/drivers/dax/dax.c @@ -36,36 +36,27 @@ static struct kmem_cache *dax_cache __read_mostly; static struct super_block *dax_superblock __read_mostly; MODULE_PARM_DESC(nr_dax, "max number of device-dax instances"); +/* + * Rely on the fact that drvdata is set before the attributes are + * registered, and that the attributes are unregistered before drvdata + * is cleared to assume that drvdata is always valid. + */ static ssize_t id_show(struct device *dev, struct device_attribute *attr, char *buf) { - struct dax_region *dax_region; - ssize_t rc = -ENXIO; + struct dax_region *dax_region = dev_get_drvdata(dev); - device_lock(dev); - dax_region = dev_get_drvdata(dev); - if (dax_region) - rc = sprintf(buf, "%d\n", dax_region->id); - device_unlock(dev); - - return rc; + return sprintf(buf, "%d\n", dax_region->id); } static DEVICE_ATTR_RO(id); static ssize_t region_size_show(struct device *dev, struct device_attribute *attr, char *buf) { - struct dax_region *dax_region; - ssize_t rc = -ENXIO; + struct dax_region *dax_region = dev_get_drvdata(dev); - device_lock(dev); - dax_region = dev_get_drvdata(dev); - if (dax_region) - rc = sprintf(buf, "%llu\n", (unsigned long long) - resource_size(&dax_region->res)); - device_unlock(dev); - - return rc; + return sprintf(buf, "%llu\n", (unsigned long long) + resource_size(&dax_region->res)); } static struct device_attribute dev_attr_region_size = __ATTR(size, 0444, region_size_show, NULL); @@ -73,16 +64,9 @@ static struct device_attribute dev_attr_region_size = __ATTR(size, 0444, static ssize_t align_show(struct device *dev, struct device_attribute *attr, char *buf) { - struct dax_region *dax_region; - ssize_t rc = -ENXIO; + struct dax_region *dax_region = dev_get_drvdata(dev); - device_lock(dev); - dax_region = dev_get_drvdata(dev); - if (dax_region) - rc = sprintf(buf, "%u\n", dax_region->align); - device_unlock(dev); - - return rc; + return sprintf(buf, "%u\n", dax_region->align); } static DEVICE_ATTR_RO(align);