Re: [PATCH -next] RDMA/hns: Fix return in hns_roce_rereg_user_mr()

[Jason Gunthorpe]

On Thu, Aug 05, 2021 at 01:58:53PM +0300, Leon Romanovsky wrote:

> > IMO, if ibv_rereg_mr failed, the mr is in undefined state, user
> > needs to call ibv_dereg_mr in order to release it, so there no
> > need to recover the original state.
> 
> The thing is that it undefined state in the kernel.  What will be if
> user will change access_flags and try to use that "broken" MR
> anyway? Will you catch it?

rereg is not atomic, if the rereg fails in the middle the mr should be
left in some safe state.

Jason