lightnvm: pblk: add lock protection to list operations

Protect the list_add on the pblk_line_init_bb() error
path in case this code is used for some other purpose
in the future.
Signed-off-by: Hua Su <suhua.tanke@gmail.com>
Reviewed-by: Javier González <javier@cnexlabs.com>
Signed-off-by: Matias Bjørling <mb@lightnvm.io>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/lightnvm/pblk-core.c

@@ -1295,15 +1295,22 @@ int pblk_line_recov_alloc(struct pblk *pblk, struct pblk_line *line)
 
 	ret = pblk_line_alloc_bitmaps(pblk, line);
 	if (ret)
-		return ret;
+		goto fail;
 
 	if (!pblk_line_init_bb(pblk, line, 0)) {
-		list_add(&line->list, &l_mg->free_list);
-		return -EINTR;
+		ret = -EINTR;
+		goto fail;
 	}
 
 	pblk_rl_free_lines_dec(&pblk->rl, line, true);
 	return 0;
+
+fail:
+	spin_lock(&l_mg->free_lock);
+	list_add(&line->list, &l_mg->free_list);
+	spin_unlock(&l_mg->free_lock);
+
+	return ret;
 }
 
 void pblk_line_recov_close(struct pblk *pblk, struct pblk_line *line)