On Thu, Jan 26, 2023 at 12:42:08PM +0200, Leon Romanovsky wrote:
> On Thu, Jan 26, 2023 at 10:45:50AM +0100, Paolo Abeni wrote:
> > On Thu, 2023-01-26 at 09:28 +0200, Leon Romanovsky wrote:
> > > On Wed, Jan 25, 2023 at 11:02:26AM -0800, Jakub Kicinski wrote:
> > > > On Tue, 24 Jan 2023 13:54:57 +0200 Leon Romanovsky wrote:
> > > > > - err = dev->xfrmdev_ops->xdo_dev_policy_add(xp);
> > > > > + err = dev->xfrmdev_ops->xdo_dev_policy_add(xp, extack);
> > > > > if (err) {
> > > > > xdo->dev = NULL;
> > > > > xdo->real_dev = NULL;
> > > > > xdo->type = XFRM_DEV_OFFLOAD_UNSPECIFIED;
> > > > > xdo->dir = 0;
> > > > > netdev_put(dev, &xdo->dev_tracker);
> > > > > - NL_SET_ERR_MSG(extack, "Device failed to offload this policy");
> > > >
> > > > In a handful of places we do:
> > > >
> > > > if (!extack->msg)
> > > > NL_SET_ERR_MSG(extack, "Device failed to offload this policy");
> > > >
> > > > in case the device did not provide the extack.
> > > > Dunno if it's worth doing here.
> > >
> > > Honestly, I followed devlink.c which didn't do that, but looked again
> > > and found that devlink can potentially overwrite messages :)
> > >
> > > For example in this case:
> > > 997 err = ops->port_fn_state_get(port, &state, &opstate, extack);
> > > 998 if (err) {
> > > 999 if (err == -EOPNOTSUPP)
> > > 1000 return 0;
> > > 1001 return err;
> > > 1002 }
> > > 1003 if (!devlink_port_fn_state_valid(state)) {
> > > 1004 WARN_ON_ONCE(1);
> > > 1005 NL_SET_ERR_MSG_MOD(extack, "Invalid state read from driver");
> > > 1006 return -EINVAL;
> > > 1007 }
> > >
> > >
> > > So what do you think about the following change, so we can leave
> > > NL_SET_ERR_MSG_MOD() in devlink and xfrm intact?
> > >
> > > diff --git a/include/linux/netlink.h b/include/linux/netlink.h
> > > index 38f6334f408c..d6f3a958e30b 100644
> > > --- a/include/linux/netlink.h
> > > +++ b/include/linux/netlink.h
> > > @@ -101,7 +101,7 @@ struct netlink_ext_ack {
> > > \
> > > do_trace_netlink_extack(__msg); \
> > > \
> > > - if (__extack) \
> > > + if (__extack && !__extack->msg) \
> > > __extack->_msg = __msg; \
> > > } while (0)
> > >
> > > @@ -111,7 +111,7 @@ struct netlink_ext_ack {
> > > #define NL_SET_ERR_MSG_FMT(extack, fmt, args...) do { \
> > > struct netlink_ext_ack *__extack = (extack); \
> > > \
> > > - if (!__extack) \
> > > + if (!__extack || __extack->msg) \
> > > break; \
> > > if (snprintf(__extack->_msg_buf, NETLINK_MAX_FMTMSG_LEN, \
> > > "%s" fmt "%s", "", ##args, "") >= \
> > >
> >
> > I think it makes sense. With the above patch 3/10 should be updated to
> > preserve the 'catch-all' error message, I guess.
>
> Great, thanks
>
> >
> > Let's see what Jakub thinks ;)
https://lore.kernel.org/netdev/2919eb55e2e9b92265a3ba600afc8137a901ae5f.1674760340.git.leon@xxxxxxxxxx/T/#u
> >
> > Cheers,
> >
> > Paolo
> >
