Wed, Aug 09, 2023 at 08:26:38PM CEST, kuba@kernel.org wrote:

One of the biggest (which is not to say only) annoyances with genetlink
handling today is that doit and dumpit need some of the same information,
but it is passed to them in completely different structs.

The implementations commonly end up writing a _fill() method which
populates a message and have to pass at least 6 parameters. 3 of which
are extracted manually from request info.

After a lot of umming and ahing I decided to populate struct genl_info
for dumps, without trying to factor out only the common parts.
This makes the adoption easiest.

In the future we may add a new version of dump which takes
struct genl_info *info as the second argument, instead of

That would be very nice. I'm dreaming about that for quite some time :)

struct netlink_callback *cb. For now developers have to call
genl_info_dump(cb) to get the info.

Typical genetlink families no longer get exposed to netlink protocol
internals like pid and seq numbers.

Jakub Kicinski (10):
 genetlink: use push conditional locking info dumpit/done
 genetlink: make genl_info->nlhdr const
 genetlink: remove userhdr from struct genl_info
 genetlink: add struct genl_info to struct genl_dumpit_info
 genetlink: use attrs from struct genl_info
 genetlink: add a family pointer to struct genl_info
 genetlink: add genlmsg_iput() API
 netdev-genl: use struct genl_info for reply construction
 ethtool: netlink: simplify arguments to ethnl_default_parse()
 ethtool: netlink: always pass genl_info to .prepare_data

drivers/block/drbd/drbd_nl.c    |   9 +--
drivers/net/wireguard/netlink.c |   2 +-
include/net/genetlink.h         |  72 +++++++++++++++++--
net/core/netdev-genl.c          |  15 ++--
net/devlink/health.c            |   2 +-
net/devlink/leftover.c          |   6 +-
net/ethtool/channels.c          |   2 +-
net/ethtool/coalesce.c          |   6 +-
net/ethtool/debug.c             |   2 +-
net/ethtool/eee.c               |   2 +-
net/ethtool/eeprom.c            |   9 ++-
net/ethtool/features.c          |   2 +-
net/ethtool/fec.c               |   2 +-
net/ethtool/linkinfo.c          |   2 +-
net/ethtool/linkmodes.c         |   2 +-
net/ethtool/linkstate.c         |   2 +-
net/ethtool/mm.c                |   2 +-
net/ethtool/module.c            |   5 +-
net/ethtool/netlink.c           |  31 ++++-----
net/ethtool/netlink.h           |   2 +-
net/ethtool/pause.c             |   5 +-
net/ethtool/phc_vclocks.c       |   2 +-
net/ethtool/plca.c              |   4 +-
net/ethtool/privflags.c         |   2 +-
net/ethtool/pse-pd.c            |   6 +-
net/ethtool/rings.c             |   5 +-
net/ethtool/rss.c               |   3 +-
net/ethtool/stats.c             |   5 +-
net/ethtool/strset.c            |   2 +-
net/ethtool/tsinfo.c            |   2 +-
net/ethtool/tunnels.c           |   2 +-
net/ethtool/wol.c               |   5 +-
net/ieee802154/nl802154.c       |   4 +-
net/ncsi/ncsi-netlink.c         |   2 +-
net/ncsi/ncsi-netlink.h         |   2 +-
net/netlink/genetlink.c         | 119 +++++++++++++++-----------------
net/nfc/netlink.c               |   4 +-
net/openvswitch/conntrack.c     |   2 +-
net/openvswitch/datapath.c      |  29 ++++----
net/openvswitch/meter.c         |  10 +--
net/tipc/netlink_compat.c       |   4 +-
net/tipc/node.c                 |   4 +-
net/tipc/socket.c               |   2 +-
net/tipc/udp_media.c            |   2 +-
44 files changed, 226 insertions(+), 178 deletions(-)

-- 
2.41.0