null_blk: fix return value from null_add_dev()

The function nullb_device_power_store() returns -ENOMEM when
null_add_dev() fails. null_add_dev() can fail with return value
other than -ENOMEM such as -EINVAL when Zoned Block Device option
is used, see :

nullb_device_power_store()
 null_add_dev()
  null_init_zoned_dev()
	return -EINVAL;

When trying to load the module having -ENOMEM value returned on the
command line creates confusion when pleanty of memory is free on the
machine.

Instead of hardcoding -ENOMEM return the value of null_add_dev()
function.

Signed-off-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220215115951.15945-1-kch@nvidia.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c
index 13004be..90b6bd2 100644 (file)
--- a/drivers/block/null_blk/main.c
+++ b/drivers/block/null_blk/main.c
@@ -431,9 +431,10 @@ static ssize_t nullb_device_power_store(struct config_item *item,
        if (!dev->power && newp) {
                if (test_and_set_bit(NULLB_DEV_FL_UP, &dev->flags))
                        return count;
-               if (null_add_dev(dev)) {
+               ret = null_add_dev(dev);
+               if (ret) {
                        clear_bit(NULLB_DEV_FL_UP, &dev->flags);
-                       return -ENOMEM;
+                       return ret;
                }
 
                set_bit(NULLB_DEV_FL_CONFIGURED, &dev->flags);