Re: [PATCH for-next v12 1/6] RDMA/rxe: Add code to cleanup mcast memory

[Jason Gunthorpe <jgg@nvidia.com>]

On Thu, Feb 17, 2022 at 06:35:39PM -0600, Bob Pearson wrote:
> Well behaved applications will free all memory allocated by multicast.
> If this fails rdma-core will detach all qp's from multicast groups when
> an application terminates. This patch prints a warning and cleans out
> memory allocated by multicast if both of these fail to occur.
> 
> Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
>  drivers/infiniband/sw/rxe/rxe.c       |  2 ++
>  drivers/infiniband/sw/rxe/rxe_loc.h   |  1 +
>  drivers/infiniband/sw/rxe/rxe_mcast.c | 38 +++++++++++++++++++++++++++
>  3 files changed, 41 insertions(+)
> 
> diff --git a/drivers/infiniband/sw/rxe/rxe.c b/drivers/infiniband/sw/rxe/rxe.c
> index 3520eb2db685..603b0156f889 100644
> +++ b/drivers/infiniband/sw/rxe/rxe.c
> @@ -29,6 +29,8 @@ void rxe_dealloc(struct ib_device *ib_dev)
>  	rxe_pool_cleanup(&rxe->mr_pool);
>  	rxe_pool_cleanup(&rxe->mw_pool);
>  
> +	rxe_cleanup_mcast(rxe);

Lets just put

WARN_ON(!RB_EMPTY_ROOT(&rxe->mcg_tree));

Righ here and forget about there rest. Leaking memory if the kernel is
buggy is OK.

Jason