Re: [PATCH net] net: make netdev_for_each_lower_dev safe for device removal

[David Ahern <dsa@cumulusnetworks.com>]

On 2/17/16 10:00 AM, Nikolay Aleksandrov wrote:
> From: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
>
> When I used netdev_for_each_lower_dev in commit bad531623253 ("vrf:
> remove slave queue and private slave struct") I thought that it acts
> like netdev_for_each_lower_private and can be used to remove the current
> device from the list while walking, but unfortunately it acts more like
> netdev_for_each_lower_private_rcu and doesn't allow it. The difference
> is where the "iter" points to, right now it points to the current element
> and that makes it impossible to remove it. Change the logic to be
> similar to netdev_for_each_lower_private and make it point to the "next"
> element so we can safely delete the current one. VRF is the only such
> user right now, there's no change for the read-only users.
>

-----8<-----

>
> CC: David Ahern <dsa@cumulusnetworks.com>
> CC: David S. Miller <davem@davemloft.net>
> CC: Roopa Prabhu <roopa@cumulusnetworks.com>
> CC: Vlad Yasevich <vyasevic@redhat.com>
> Fixes: bad531623253 ("vrf: remove slave queue and private slave struct")
> Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
> ---
>   include/linux/netdevice.h | 2 +-
>   net/core/dev.c            | 4 ++--
>   2 files changed, 3 insertions(+), 3 deletions(-)

Solves the problem for me. Thanks for the quick turnaround, Nik.

Reviewed-by / Tested-by: David Ahern <dsa@cumulusnetworks.com>