[PATCH net-next 0/5] netconsole: Add support for msgid in sysdata

[Gustavo Luiz Duarte <gustavold@gmail.com>]

This patch series introduces a new feature to netconsole which allows
appending a message ID to the userdata dictionary.

If the msgid feature is enabled, the message ID is built from a per-target 32
bit counter that is incremented and appended to every message sent to the target.

Example::
  echo 1 > "/sys/kernel/config/netconsole/cmdline0/userdata/msgid_enabled"
  echo "This is message #1" > /dev/kmsg
  echo "This is message #2" > /dev/kmsg
  13,434,54928466,-;This is message #1
   msgid=1
  13,435,54934019,-;This is message #2
   msgid=2

This feature can be used by the target to detect if messages were dropped or
reordered before reaching the target. This allows system administrators to
assess the reliability of their netconsole pipeline and detect loss of messages
due to network contention or temporary unavailability.

Suggested-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Gustavo Luiz Duarte <gustavold@gmail.com>

Note to maintainer:
This will conflict with a fix I sent recently to net:

c85bf1975108 netconsole: fix appending sysdata when sysdata_fields ==
SYSDATA_RELEASE

Please let me know if I should rebase at some point and send a v2.

---
Gustavo Luiz Duarte (5):
      netconsole: introduce 'msgid' as a new sysdata field
      netconsole: implement configfs for msgid_enabled
      netconsole: append msgid to sysdata
      selftests: netconsole: Add tests for 'msgid' feature in sysdata
      docs: netconsole: document msgid feature

 Documentation/networking/netconsole.rst            | 22 +++++++
 drivers/net/netconsole.c                           | 67 +++++++++++++++++++++-
 .../selftests/drivers/net/netcons_sysdata.sh       | 30 ++++++++++
 3 files changed, 118 insertions(+), 1 deletion(-)
---
base-commit: 0097c4195b1d0ca57d15979626c769c74747b5a0
change-id: 20250609-netconsole-msgid-b93c6f8e9c60

Best regards,
-- 
Gustavo Luiz Duarte <gustavold@gmail.com>