Re: [PATCH] macvlan.c: schedule port->bc_work even if error

From: David Miller
Date: Mon Nov 25 2019 - 01:58:39 EST


From: Menglong Dong <dong.menglong@xxxxxxxxxx>
Date: Mon, 25 Nov 2019 14:59:03 +0800

> While enqueueing a broadcast skb to port->bc_queue, schedule_work()
> is called to add port->bc_work, which processes the skbs in
> bc_queue, to "events" work queue. If port->bc_queue is full, the
> skb will be discarded and schedule_work(&port->bc_work) won't be
> called. However, if port->bc_queue is full and port->bc_work is not
> running or pending, port->bc_queue will keep full and schedule_work()
> won't be called any more, and all broadcast skbs to macvlan will be
> discarded. This case can happen:
>
> macvlan_process_broadcast() is the pending function of port->bc_work,
> it moves all the skbs in port->bc_queue to the queue "list", and
> processes the skbs in "list". During this, new skbs will keep being
> added to port->bc_queue in macvlan_broadcast_enqueue(), and
> port->bc_queue may already full when macvlan_process_broadcast()
> return. This may happen, especially when there are a lot of real-time
> threads and the process is preempted.
>
> Fix this by calling schedule_work(&port->bc_work) even if
> port->bc_work is full in macvlan_broadcast_enqueue()
>
> Signed-off-by: Menglong Dong <dong.menglong@xxxxxxxxxx>

The subsystem prefix in your Subject line should not be a source
file, but the name of the module or area you are making changes
to.

Therefore this should be "macvlan: " not "macvlan.c: "

You must also provide an appropriate Fixes: tag when fixing a problem
like this.

Thank you.