We need to pass 'end - 1' to ida_alloc_max after switch from ida_simple_get to ida_alloc_max. And smatch warns. drivers/block/rnbd/rnbd-clt.c:1460 init_dev() error: Calling ida_alloc_max() with a 'max' argument which is a power of 2. -1 missing? Fixes: 24afc15dbe21 ("block/rnbd: Remove a useless mutex") Reported-by: kernel test robot <lkp@xxxxxxxxx> Reported-by: Dan Carpenter <error27@xxxxxxxxx> Signed-off-by: Guoqing Jiang <guoqing.jiang@xxxxxxxxx> --- drivers/block/rnbd/rnbd-clt.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/block/rnbd/rnbd-clt.c b/drivers/block/rnbd/rnbd-clt.c index 78334da74d8b..8cdecec89d74 100644 --- a/drivers/block/rnbd/rnbd-clt.c +++ b/drivers/block/rnbd/rnbd-clt.c @@ -1440,7 +1440,7 @@ static struct rnbd_clt_dev *init_dev(struct rnbd_clt_session *sess, goto out_alloc; } - ret = ida_alloc_max(&index_ida, 1 << (MINORBITS - RNBD_PART_BITS), + ret = ida_alloc_max(&index_ida, 1 << (MINORBITS - RNBD_PART_BITS) - 1, GFP_KERNEL); if (ret < 0) { pr_err("Failed to initialize device '%s' from session %s, allocating idr failed, err: %d\n", -- 2.35.3