ipvlan: Convert ipvl_port.count to refcount_t.

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struct ipvl_port is shared between a lower device and its upper
ipvlan devices.

While each upper device can always access ipvl_port safely via
ipvlan_dev.port, the lower device relies on RTNL to access it
via net_device.rx_handler_data.

Once RTNL is removed, the lower device cannot read ipvl_port safely
in ipvlan_device_event() because the port could be freed concurrently
and net_device.rx_handler_data is set to NULL if the last ipvlan
device in another namespace is unregistered.

Let's convert ipvl_port.count to refcount_t and use RCU along with
refcount_inc_not_zero() in ipvlan_device_event().

netdev_put() in ipvlan_port_destroy() is also moved down after
cancel_work_sync(), which is the last user of port->dev.

Note that ipvlan->port is now set in ipvlan_init() so that it can
be used in ipvlan_uninit(), instead of ipvlan_port_get_rtnl()
(rtnl_dereference()).

Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260703001009.1572444-12-kuniyu@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

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This commit is contained in:

Kuniyuki Iwashima 2026-07-03 00:09:22 +00:00 • committed by Paolo Abeni

parent f1de92507a

commit acb351b5a8

2 changed files with 52 additions and 25 deletions

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2

drivers/net/ipvlan/ipvlan.h

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75

drivers/net/ipvlan/ipvlan_main.c

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