lightnvm: pblk: start gc if needed during init

Start GC if needed, directly after init, as we might
need to garbage collect in order to make room for user writes.

Create a helper function that allows to kick GC without exposing the
internals of the GC/rate-limiter interaction.

Signed-off-by: Hans Holmberg <hans.holmberg@cnexlabs.com>
Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/lightnvm/pblk-init.c

@@ -1025,6 +1025,10 @@ static void *pblk_init(struct nvm_tgt_dev *dev, struct gendisk *tdisk,
 			pblk->rwb.nr_entries);
 
 	wake_up_process(pblk->writer_ts);
+
+	/* Check if we need to start GC */
+	pblk_gc_should_kick(pblk);
+
 	return pblk;
 
 fail_stop_writer: