David Marchand, Nov 06, 2026 at 09:56:
When a tap interface moves to another namespace, tap_netns_change() calls tap_lsc_intr_handle_set(dev, 1) to recreate the LSC interrupt without first tearing down the old one. The previous LSC netlink socket fd is never closed.Defer the full LSC teardown and re-registration to an alarm callback which runs in the interrupt thread but outside any active source context. The alarm switches to the device's network namespace, tears down the old LSC handle, sets up a new one (opening a fresh netlink socket in the correct namespace), restores the original namespace, and forces carrier state back up. Extract tap_dev_ns_switch/tap_dev_ns_restore helpers to share the namespace switch logic between tap_netns_change and the alarm. Fixes: aae3a38e9e03 ("net/tap: detect namespace change") Cc: [email protected] Signed-off-by: David Marchand <[email protected]> Reviewed-by: Robin Jarry <[email protected]> --- Changes since v1: - moved pmd->if_index clearing before trying to change netns, - moved alarm registration after netns changes succeed, - added second alarm cancel for unregister race with netns change, - ignored ENOENT suggestion from AI review, - added error logs to please AI review, --- drivers/net/tap/rte_eth_tap.c | 99 +++++++++++++++++++++++++---------- 1 file changed, 72 insertions(+), 27 deletions(-)
Tested-by: Robin Jarry <[email protected]>
