On Thu, Mar 10, 2022 at 04:00:52PM +0100, Hans Schultz wrote:
> >> + brport = dsa_port_to_bridge_port(dp);
> >
> > Since this is threaded interrupt context, I suppose it could race with
> > dsa_port_bridge_leave(). So it is best to check whether "brport" is NULL
> > or not.
> >
> Would something like:
> if (dsa_is_unused_port(chip->ds, port))
> return -ENODATA;
>
> be appropriate and sufficient for that?
static inline
struct net_device *dsa_port_to_bridge_port(const struct dsa_port *dp)
{
if (!dp->bridge)
return NULL;
if (dp->lag)
return dp->lag->dev;
else if (dp->hsr_dev)
return dp->hsr_dev;
return dp->slave;
}
Notice the "dp->bridge" check. The assignments are in dsa_port_bridge_create()
and in dsa_port_bridge_destroy(). These functions assume rtnl_mutex protection.
The question was how do you serialize with that, and why do you assume
that dsa_port_to_bridge_port() returns non-NULL.
So no, dsa_is_unused_port() would do absolutely nothing to help.
