Re: [PATCH] RDMA/rtrs-srv: Replace device_register with device_initialize and device_add

[Haris Iqbal <haris.iqbal@cloud.ionos.com>]

On Tue, Aug 11, 2020 at 2:58 PM Md Haris Iqbal
<haris.iqbal@cloud.ionos.com> wrote:
>
> There are error cases when we will call free_srv before device kobject is
> initialized; in such cases calling put_device generates the following
> warning,
>
> kobject: '(null)' (000000009f5445ed): is not initialized, yet
> kobject_put() is being called.
>
> It was suggested by Jason to call device_initialize() sooner.
>
> So call device_initialize() only once when the server is allocated. If we
> end up calling put_srv() and subsequently free_srv(), our call to
> put_device() would result in deletion of the obj. Call device_add() later
> when we actually have a connection. Correspondingly, call device_del()
> instead of device_unregister() when srv->dev_ref falls to 0.
>
> Fixes: 9cb837480424 ("RDMA/rtrs: server: main functionality")
> Signed-off-by: Md Haris Iqbal <haris.iqbal@cloud.ionos.com>
> Reviewed-by: Jack Wang <jinpu.wang@cloud.ionos.com>
> ---
>  drivers/infiniband/ulp/rtrs/rtrs-srv-sysfs.c | 8 ++++----
>  drivers/infiniband/ulp/rtrs/rtrs-srv.c       | 1 +
>  2 files changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/infiniband/ulp/rtrs/rtrs-srv-sysfs.c b/drivers/infiniband/ulp/rtrs/rtrs-srv-sysfs.c
> index 3d7877534bcc..2f981ae97076 100644
> --- a/drivers/infiniband/ulp/rtrs/rtrs-srv-sysfs.c
> +++ b/drivers/infiniband/ulp/rtrs/rtrs-srv-sysfs.c
> @@ -182,16 +182,16 @@ static int rtrs_srv_create_once_sysfs_root_folders(struct rtrs_srv_sess *sess)
>          * sysfs files are created
>          */
>         dev_set_uevent_suppress(&srv->dev, true);
> -       err = device_register(&srv->dev);
> +       err = device_add(&srv->dev);
>         if (err) {
> -               pr_err("device_register(): %d\n", err);
> +               pr_err("device_add(): %d\n", err);
>                 goto put;
>         }
>         srv->kobj_paths = kobject_create_and_add("paths", &srv->dev.kobj);
>         if (!srv->kobj_paths) {
>                 err = -ENOMEM;
>                 pr_err("kobject_create_and_add(): %d\n", err);
> -               device_unregister(&srv->dev);
> +               device_del(&srv->dev);
>                 goto unlock;
>         }
>         dev_set_uevent_suppress(&srv->dev, false);
> @@ -216,7 +216,7 @@ rtrs_srv_destroy_once_sysfs_root_folders(struct rtrs_srv_sess *sess)
>                 kobject_del(srv->kobj_paths);
>                 kobject_put(srv->kobj_paths);
>                 mutex_unlock(&srv->paths_mutex);
> -               device_unregister(&srv->dev);
> +               device_del(&srv->dev);
>         } else {
>                 mutex_unlock(&srv->paths_mutex);
>         }
> diff --git a/drivers/infiniband/ulp/rtrs/rtrs-srv.c b/drivers/infiniband/ulp/rtrs/rtrs-srv.c
> index a219bd1bdbc2..b61a18e57aeb 100644
> --- a/drivers/infiniband/ulp/rtrs/rtrs-srv.c
> +++ b/drivers/infiniband/ulp/rtrs/rtrs-srv.c
> @@ -1336,6 +1336,7 @@ static struct rtrs_srv *__alloc_srv(struct rtrs_srv_ctx *ctx,
>         uuid_copy(&srv->paths_uuid, paths_uuid);
>         srv->queue_depth = sess_queue_depth;
>         srv->ctx = ctx;
> +       device_initialize(&srv->dev);
>
>         srv->chunks = kcalloc(srv->queue_depth, sizeof(*srv->chunks),
>                               GFP_KERNEL);
> --
> 2.25.1
>
Ping! Hi Jason, can you take this in your queue.

-- 

Regards
-Haris