On Thu, Jan 03, 2019 at 10:05:59AM +0200, Leon Romanovsky wrote:
> From: Leon Romanovsky <leonro@xxxxxxxxxxxx>
>
> XArray uses internal lock for updates to XArray. This means that our
> external RW lock is not needed anymore and we can delete it.
The xarray lock only protects the array itself - not the things it
points to.
> - down_read(&res->rwsem);
> xa_for_each(&res->xa[type], e, index, ULONG_MAX, XA_PRESENT) {
> if (ns == &init_pid_ns ||
> (!rdma_is_kernel_res(e) &&
So eg here, 'e' is still needs the locking to protect against
concurrent restrack_del causing e to be freed.
Most likely the internal xarray locking doesn't save anything in this
usage..
Jason
