From: Dan Williams <dan.j.williams@intel.com> mainline inclusion from mainline-v5.1-rc1 commit 664525b2d84abca1074c9546654ae9689de8a818 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I47H3V CVE: NA -------------------------------- commit 664525b2d84abca1074c9546654ae9689de8a818 upstream. The typical 'new_id' attribute behavior is to immediately attach a device to its driver after a new device-id is added. Implement this behavior for the dax bus. Reported-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> Reported-by: Brice Goglin <Brice.Goglin@inria.fr> Cc: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Fan Du <fan.du@intel.com> Signed-off-by: Jackie Liu <liuyun01@kylinos.cn> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> Reviewed-by: Xie XiuQi <xiexiuqi@huawei.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- drivers/dax/bus.c | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-) diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c index c620ad52d7e5c..a410154d75fb9 100644 --- a/drivers/dax/bus.c +++ b/drivers/dax/bus.c @@ -57,8 +57,13 @@ static int dax_match_id(struct dax_device_driver *dax_drv, struct device *dev) return match; } +enum id_action { + ID_REMOVE, + ID_ADD, +}; + static ssize_t do_id_store(struct device_driver *drv, const char *buf, - size_t count, bool add) + size_t count, enum id_action action) { struct dax_device_driver *dax_drv = to_dax_drv(drv); unsigned int region_id, id; @@ -77,7 +82,7 @@ static ssize_t do_id_store(struct device_driver *drv, const char *buf, mutex_lock(&dax_bus_lock); dax_id = __dax_match_id(dax_drv, buf); if (!dax_id) { - if (add) { + if (action == ID_ADD) { dax_id = kzalloc(sizeof(*dax_id), GFP_KERNEL); if (dax_id) { strncpy(dax_id->dev_name, buf, DAX_NAME_LEN); @@ -86,26 +91,33 @@ static ssize_t do_id_store(struct device_driver *drv, const char *buf, rc = -ENOMEM; } else /* nothing to remove */; - } else if (!add) { + } else if (action == ID_REMOVE) { list_del(&dax_id->list); kfree(dax_id); } else /* dax_id already added */; mutex_unlock(&dax_bus_lock); - return rc; + + if (rc < 0) + return rc; + if (action == ID_ADD) + rc = driver_attach(drv); + if (rc) + return rc; + return count; } static ssize_t new_id_store(struct device_driver *drv, const char *buf, size_t count) { - return do_id_store(drv, buf, count, true); + return do_id_store(drv, buf, count, ID_ADD); } static DRIVER_ATTR_WO(new_id); static ssize_t remove_id_store(struct device_driver *drv, const char *buf, size_t count) { - return do_id_store(drv, buf, count, false); + return do_id_store(drv, buf, count, ID_REMOVE); } static DRIVER_ATTR_WO(remove_id); -- 2.25.1