Re: [PATCH net] net: expect instance lock in netdev_queue_get_dma_dev()

On Thu, Aug 06, 2026 at 03:56:26PM -0700, Jakub Kicinski wrote:
> netdev_queue_get_dma_dev() uses "compat" locking assert which wants
> either the rtnl_lock or netdev instance lock. This is not right,
> the callers are taking the instance lock unconditionally. All entry
> points for queue config are purely instance locked.
> 
> In other words the callers use netdev_get_by_index_lock(), not
> netdev_get_by_index_lock_ops_compat(). All the state we will
> access is effectively instance lock protected (it's const for
> devices which are not ops-locked).
> 
> Update the assert to avoid false positive warnings.
> 
> Cc: [email protected]
> Fixes: b6c5f9454ef34 ("io_uring/zcrx: call netdev_queue_get_dma_dev() under instance lock")
> Reported-by: [email protected]
> Signed-off-by: Jakub Kicinski <[email protected]>

Reviewed-by: Simon Horman <[email protected]>