Re: [PATCH] IB/rdmavt: add missing locks in rvt_ruc_loopback

From: Jason Gunthorpe
Date: Fri Apr 08 2022 - 12:31:38 EST


On Mon, Feb 28, 2022 at 08:51:44PM +0100, Niels Dossche wrote:
> The documentation of the function rvt_error_qp says both r_lock and
> s_lock need to be held when calling that function.
> It also asserts using lockdep that both of those locks are held.
> rvt_error_qp is called form rvt_send_cq, which is called from
> rvt_qp_complete_swqe, which is called from rvt_send_complete, which is
> called from rvt_ruc_loopback in two places. Both of these places do not
> hold r_lock. Fix this by acquiring a spin_lock of r_lock in both of
> these places.
> The r_lock acquiring cannot be added in rvt_qp_complete_swqe because
> some of its other callers already have r_lock acquired.
>
> Signed-off-by: Niels Dossche <dossche.niels@xxxxxxxxx>
> ---
> drivers/infiniband/sw/rdmavt/qp.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)

Applied to for-next, thanks

Jason