Currently mbps knob could only be set once before switching power knob to on, after power knob has been set at least once, there is no way to set mbps knob again due to -EBUSY. As nullb is mainly used for testing, in order to make it flexible, this removes the flag NULLB_DEV_FL_CONFIGURED so that mbps knob can be reset when power knob is off, e.g. echo 0 > /config/nullb/a/power echo 40 > /config/nullb/a/mbps echo 1 > /config/nullb/a/power So does other knobs under /config/nullb/a. Signed-off-by: Liu Bo <bo.liu@xxxxxxxxxxxxxxxxx> --- drivers/block/null_blk.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c index 2bdadd7f1454..ec0c49867996 100644 --- a/drivers/block/null_blk.c +++ b/drivers/block/null_blk.c @@ -390,6 +390,7 @@ static ssize_t nullb_device_power_store(struct config_item *item, null_del_dev(dev->nullb); mutex_unlock(&lock); clear_bit(NULLB_DEV_FL_UP, &dev->flags); + clear_bit(NULLB_DEV_FL_CONFIGURED, &dev->flags); } return count; -- 1.8.3.1