From: Vlad Buslov <vla...@mellanox.com>
Date: Wed, 24 Apr 2019 09:53:31 +0300
> Recent changes that introduced unlocked flower did not properly account for
> case when reoffload is initiated concurrently with filter updates. To fix
> the issue, extend flower with 'hw_filters' list that is used to store
> filters that don't have 'skip_hw' flag set. Filter is added to the list
> when it is inserted to hardware and only removed from it after being
> unoffloaded from all drivers that parent block is attached to. This ensures
> that concurrent reoffload can still access filter that is being deleted and
> prevents race condition when driver callback can be removed when filter is
> no longer accessible trough idr, but is still present in hardware.
>
> Refactor fl_change() to respect new filter reference counter and to release
> filter reference with __fl_put() in case of error, instead of directly
> deallocating filter memory. This allows for concurrent access to filter
> from fl_reoffload() and protects it with reference counting. Refactor
> fl_reoffload() to iterate over hw_filters list instead of idr. Implement
> fl_get_next_hw_filter() helper function that is used to iterate over
> hw_filters list with reference counting and skips filters that are being
> concurrently deleted.
>
> Fixes: 92149190067d ("net: sched: flower: set unlocked flag for flower proto
> ops")
> Signed-off-by: Vlad Buslov <vla...@mellanox.com>
Applied, thank you.
