netdev at kapio-technology.com
2023-Feb-02 16:38 UTC
[Bridge] [PATCH net-next 1/5] net: bridge: add dynamic flag to switchdev notifier
On 2023-02-02 17:11, Ido Schimmel wrote:> On Thu, Feb 02, 2023 at 08:28:36AM +0100, netdev at kapio-technology.com > wrote: >> On 2023-02-01 19:10, Ido Schimmel wrote: >> > On Mon, Jan 30, 2023 at 06:34:25PM +0100, Hans J. Schultz wrote: >> > > To be able to add dynamic FDB entries to drivers from userspace, the >> > > dynamic flag must be added when sending RTM_NEWNEIGH events down. >> > > >> > > Signed-off-by: Hans J. Schultz <netdev at kapio-technology.com> >> > > --- >> > > include/net/switchdev.h | 1 + >> > > net/bridge/br_switchdev.c | 2 ++ >> > > 2 files changed, 3 insertions(+) >> > > >> > > diff --git a/include/net/switchdev.h b/include/net/switchdev.h >> > > index ca0312b78294..aaf918d4ba67 100644 >> > > --- a/include/net/switchdev.h >> > > +++ b/include/net/switchdev.h >> > > @@ -249,6 +249,7 @@ struct switchdev_notifier_fdb_info { >> > > u8 added_by_user:1, >> > > is_local:1, >> > > locked:1, >> > > + is_dyn:1, >> > > offloaded:1; >> > > }; >> > > >> > > diff --git a/net/bridge/br_switchdev.c b/net/bridge/br_switchdev.c >> > > index 7eb6fd5bb917..4420fcbbfdb2 100644 >> > > --- a/net/bridge/br_switchdev.c >> > > +++ b/net/bridge/br_switchdev.c >> > > @@ -136,6 +136,8 @@ static void br_switchdev_fdb_populate(struct >> > > net_bridge *br, >> > > item->added_by_user = test_bit(BR_FDB_ADDED_BY_USER, &fdb->flags); >> > > item->offloaded = test_bit(BR_FDB_OFFLOADED, &fdb->flags); >> > > item->is_local = test_bit(BR_FDB_LOCAL, &fdb->flags); >> > > + item->is_dyn = !test_bit(BR_FDB_STATIC, &fdb->flags) && >> > >> > Why not 'is_static' and be consistent with the bridge flag like all the >> > other fields? >> > >> > Regardless of how you name this field, it is irrelevant for >> > 'SWITCHDEV_FDB_ADD_TO_BRIDGE' notifications that all add FDB entries >> > with the 'BR_FDB_ADDED_BY_EXT_LEARN' flag set, which makes >> > 'BR_FDB_STATIC' irrelevant. >> > >> > > + item->added_by_user; >> > >> > Unclear why this is needed... >> > >> >> The answer to those two questions lies in my earlier correspondences >> (with >> Oltean) on the RFC version. > > It is not up to me as a reviewer to dig up old versions of the patch > and > find out what was changed and why. It is up to you as the submitter of > the patch to provide all this information in the patch posting. Please > read: > https://www.kernel.org/doc/html/latest/process/submitting-patches.html > > Specifically: > > "Review comments or questions that do not lead to a code change should > almost certainly bring about a comment or changelog entry so that the > next reviewer better understands what is going on." > > And: > > "Other comments relevant only to the moment or the maintainer, not > suitable for the permanent changelog, should also go here. A good > example of such comments might be patch changelogs which describe what > has changed between the v1 and v2 version of the patch. > > Please put this information after the --- line which separates the > changelog from the rest of the patch. The version information is not > part of the changelog which gets committed to the git tree. It is > additional information for the reviewers." > > ThanksSorry about that. I thought it would be easily found... On the first question please look here: https://lore.kernel.org/netdev/20230119134045.fqdt6zrna5x3iavt at skbuf/ On the second question it is what Oltean pointed out to me here... https://lore.kernel.org/netdev/20230118230135.szu6a7kvt2mjb3i5 at skbuf/ Oltean says there: "This is not true, because it assumes that DSA never called port_fdb_add() up until now for bridge FDB entries with the BR_FDB_STATIC flag unset, which is incorrect (it did)." Though as I see it, if it is only from the DSA layer on, the new is_dynamic flag would not be set anyway in the case he references. And as can be seen the change is in the bridge layer, as the rest is just propagating the flag, but it ensures that to set this flag that it comes from the user adding an FDB entry.
Ido Schimmel
2023-Feb-03 16:14 UTC
[Bridge] [PATCH net-next 1/5] net: bridge: add dynamic flag to switchdev notifier
On Thu, Feb 02, 2023 at 05:38:06PM +0100, netdev at kapio-technology.com wrote:> On the first question please look here: > https://lore.kernel.org/netdev/20230119134045.fqdt6zrna5x3iavt at skbuf/It seems Vladimir also wants the new field to be named 'is_static' instead of 'is_dyn'. In your reason you mention 'SWITCHDEV_FDB_ADD_TO_BRIDGE', but this is not the interesting case for the field. This event is used for devices to notify the bridge on new learned entries. The bridge marks them as "extern_learn" which means that "dynamic" / "static" flags are irrelevant. The interesting case for the new field is the bridge to device direction ('SWITCHDEV_FDB_ADD_TO_DEVICE'). Drivers need to be patched to take the new field into account when deciding the policy to program the entry with. They can do it just as well if you name the new field 'is_static' instead of 'is_dyn'.> On the second question it is what Oltean pointed out to me here... > https://lore.kernel.org/netdev/20230118230135.szu6a7kvt2mjb3i5 at skbuf/ > > Oltean says there: > "This is not true, because it assumes that DSA never called port_fdb_add() > up until now for bridge FDB entries with the BR_FDB_STATIC flag unset, > which is incorrect (it did)." > > Though as I see it, if it is only from the DSA layer on, the new is_dynamic > flag would not be set anyway in the case he references. And as can be seen > the change is in the bridge layer, as the rest is just propagating the flag, > but it ensures that to set this flag that it comes from the user adding an > FDB entry.OK, so can't this hunk: ``` if (fdb_info->is_dyn) fdb_flags |= DSA_FDB_FLAG_DYNAMIC; ``` Become: ``` if (fdb_info->is_dyn && !fdb_info->added_by_user) fdb_flags |= DSA_FDB_FLAG_DYNAMIC; ``` ? Then there is no need to fold 'added_by_user' into 'is_dyn' in the bridge driver. I *think* this is the change Vladimir asked you to do.