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, "") >= \
