On Mon, Feb 7, 2022 at 9:48 PM Christophe JAILLET
<christophe.jaillet@xxxxxxxxxx> wrote:
>
> According to lib/idr.c,
> The IDA handles its own locking. It is safe to call any of the IDA
> functions without synchronisation in your code.
>
> so the 'ida_lock' mutex can just be removed.
> It is here only to protect some ida_simple_get()/ida_simple_remove() calls.
>
> While at it, switch to ida_alloc_XXX()/ida_free() instead to
> ida_simple_get()/ida_simple_remove().
> The latter is deprecated and more verbose.
>
> Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
Acked-by: Jack Wang <jinpu.wang@xxxxxxxxx>
Thanks!
> ---
> drivers/block/rnbd/rnbd-clt.c | 11 +++--------
> 1 file changed, 3 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/block/rnbd/rnbd-clt.c b/drivers/block/rnbd/rnbd-clt.c
> index 9a880d559ab8..1f63f308eb39 100644
> --- a/drivers/block/rnbd/rnbd-clt.c
> +++ b/drivers/block/rnbd/rnbd-clt.c
> @@ -23,7 +23,6 @@ MODULE_LICENSE("GPL");
>
> static int rnbd_client_major;
> static DEFINE_IDA(index_ida);
> -static DEFINE_MUTEX(ida_lock);
> static DEFINE_MUTEX(sess_lock);
> static LIST_HEAD(sess_list);
>
> @@ -55,9 +54,7 @@ static void rnbd_clt_put_dev(struct rnbd_clt_dev *dev)
> if (!refcount_dec_and_test(&dev->refcount))
> return;
>
> - mutex_lock(&ida_lock);
> - ida_simple_remove(&index_ida, dev->clt_device_id);
> - mutex_unlock(&ida_lock);
> + ida_free(&index_ida, dev->clt_device_id);
> kfree(dev->hw_queues);
> kfree(dev->pathname);
> rnbd_clt_put_sess(dev->sess);
> @@ -1460,10 +1457,8 @@ static struct rnbd_clt_dev *init_dev(struct rnbd_clt_session *sess,
> goto out_alloc;
> }
>
> - mutex_lock(&ida_lock);
> - ret = ida_simple_get(&index_ida, 0, 1 << (MINORBITS - RNBD_PART_BITS),
> - GFP_KERNEL);
> - mutex_unlock(&ida_lock);
> + ret = ida_alloc_max(&index_ida, 1 << (MINORBITS - RNBD_PART_BITS),
> + GFP_KERNEL);
> if (ret < 0) {
> pr_err("Failed to initialize device '%s' from session %s, allocating idr failed, err: %d\n",
> pathname, sess->sessname, ret);
> --
> 2.32.0
>
