This patchset introduces target resume capability to netconsole allowing
it to recover targets when underlying low-level interface comes back
online.
The patchset starts by refactoring netconsole state representation in
order to allow representing deactivated targets (targets that are
disabled due to interfaces unregister).
It then modifies netconsole to handle NETDEV_REGISTER events for such
targets, setups netpoll and forces the device UP. Targets are matched with
incoming interfaces depending on how they were bound in netconsole
(by mac or interface name). For these reasons, we also attempt resuming
on NETDEV_CHANGENAME.
The patchset includes a selftest that validates netconsole target state
transitions and that target is functional after resumed.
Signed-off-by: Andre Carvalho <asantostc@gmail.com>
---
Changes in v9:
- Hold dynamic_netconsole_mutex on process_resume_target.
- Cleanup dev_name as part of netconsole_process_cleanups_core to ensure
we correctly resume by mac (for targets bound by mac)
- Link to v8: https://lore.kernel.org/r/20251128-netcons-retrigger-v8-0-0bccbf4c6385@gmail.com
Changes in v8:
- Handle NETDEV_REGISTER/CHANGENAME instead of NETDEV_UP (and force the device
UP), to increase the chances of succesfully resuming a target. This
requires using a workqueue instead of inline in the event notifier as
we can't UP the device otherwise.
- Link to v7: https://lore.kernel.org/r/20251126-netcons-retrigger-v7-0-1d86dba83b1c@gmail.com
Changes in v7:
- selftest: use ${EXIT_STATUS} instead of ${ksft_pass} to avoid
shellcheck warning
- Link to v6: https://lore.kernel.org/r/20251121-netcons-retrigger-v6-0-9c03f5a2bd6f@gmail.com
Changes in v6:
- Rebase on top of net-next to resolve conflicts, no functional changes.
- Link to v5: https://lore.kernel.org/r/20251119-netcons-retrigger-v5-0-2c7dda6055d6@gmail.com
Changes in v5:
- patch 3: Set (de)enslaved target as DISABLED instead of DEACTIVATED to prevent
resuming it.
- selftest: Fix test cleanup by moving trap line to outside of loop and remove
unneeded 'local' keyword
- Rename maybe_resume_target to resume_target, add netconsole_ prefix to
process_resumable_targets.
- Hold device reference before calling __netpoll_setup.
- Link to v4: https://lore.kernel.org/r/20251116-netcons-retrigger-v4-0-5290b5f140c2@gmail.com
Changes in v4:
- Simplify selftest cleanup, removing trap setup in loop.
- Drop netpoll helper (__setup_netpoll_hold) and manage reference inside
netconsole.
- Move resume_list processing logic to separate function.
- Link to v3: https://lore.kernel.org/r/20251109-netcons-retrigger-v3-0-1654c280bbe6@gmail.com
Changes in v3:
- Resume by mac or interface name depending on how target was created.
- Attempt to resume target without holding target list lock, by moving
the target to a temporary list. This is required as netpoll may
attempt to allocate memory.
- Link to v2: https://lore.kernel.org/r/20250921-netcons-retrigger-v2-0-a0e84006237f@gmail.com
Changes in v2:
- Attempt to resume target in the same thread, instead of using
workqueue .
- Add wrapper around __netpoll_setup (patch 4).
- Renamed resume_target to maybe_resume_target and moved conditionals to
inside its implementation, keeping code more clear.
- Verify that device addr matches target mac address when target was
setup using mac.
- Update selftest to cover targets bound by mac and interface name.
- Fix typo in selftest comment and sort tests alphabetically in
Makefile.
- Link to v1:
https://lore.kernel.org/r/20250909-netcons-retrigger-v1-0-3aea904926cf@gmail.com
---
Andre Carvalho (4):
netconsole: convert 'enabled' flag to enum for clearer state management
netconsole: clear dev_name for devices bound by mac
netconsole: resume previously deactivated target
selftests: netconsole: validate target resume
Breno Leitao (2):
netconsole: add target_state enum
netconsole: add STATE_DEACTIVATED to track targets disabled by low level
drivers/net/netconsole.c | 171 +++++++++++++++++----
tools/testing/selftests/drivers/net/Makefile | 1 +
.../selftests/drivers/net/lib/sh/lib_netcons.sh | 35 ++++-
.../selftests/drivers/net/netcons_resume.sh | 97 ++++++++++++
4 files changed, 270 insertions(+), 34 deletions(-)
---
base-commit: dbf8fe85a16a33d6b6bd01f2bc606fc017771465
change-id: 20250816-netcons-retrigger-a4f547bfc867
Best regards,
--
Andre Carvalho <asantostc@gmail.com>