On Monday, June 13, 2016 07:41:32 Sven Eckelmann wrote:
> The kobject_put is only removing the sysfs entry and corresponding entries
> when its reference counter becomes zero. This tends to lead to collisions
> when a device is moved between two different network namespaces because
> some of the sysfs files have to be removed first and then added again to
> the already moved sysfs entry.
> 
>     WARNING: CPU: 0 PID: 290 at lib/kobject.c:240
> kobject_add_internal+0x5ec/0x8a0 kobject_add_internal failed for batman_adv
> with -EEXIST, don't try to register things with the same name in the same
> directory.
> 
> But the caller of kobject_put can already remove the sysfs entry before it
> does the kobject_put. This removal is done even when the reference counter
> is not yet zero and thus avoids the problem.
> 
> Signed-off-by: Sven Eckelmann <sven@narfation.org>
> ---
> v5:
>  - rebase on top of current master
> v4:
>  - rebase on top of current master
>  - avoid deletes of vlan->kobj when it is a pointer to bat_priv->mesh_obj
>    (happens for untagged vlan and can cause some kernfs warnings)
> v3:
>  - rebased on top of current master to fix conflicts with newest patches
> v2:
>  - rebased on top of current master to fix conflicts with newest patches
> ---
>  net/batman-adv/sysfs.c | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)

Applied in revision bebf178.

Thanks,
Marek