[PATCH rdma-next 00/14] Cleanup locking and events in ucma

[PATCH rdma-next 00/14] Cleanup locking and events in ucma

[Leon Romanovsky]

From: Leon Romanovsky <leonro@nvidia.com>

From Jason:

Rework how the uevents for new connections are handled so all the locking
ends up simpler and a work queue can be removed. This should also speed up
destruction of ucma_context's as a flush_workqueue() was replaced with
cancel_work_sync().

The simpler locking comes from narrowing what file->mut covers and moving
other data to other locks, particularly by injecting the handler_mutex
from the RDMA CM core as a construct available to ULPs. The handler_mutex
directly prevents handlers from running without creating any ABBA locking
problems.

Fix various error cases and data races caused by missing locking.

Thanks

Jason Gunthorpe (14):
  RDMA/ucma: Fix refcount 0 incr in ucma_get_ctx()
  RDMA/ucma: Remove unnecessary locking of file->ctx_list in close
  RDMA/ucma: Consolidate the two destroy flows
  RDMA/ucma: Fix error cases around ucma_alloc_ctx()
  RDMA/ucma: Remove mc_list and rely on xarray
  RDMA/cma: Add missing locking to rdma_accept()
  RDMA/ucma: Do not use file->mut to lock destroying
  RDMA/ucma: Fix the locking of ctx->file
  RDMA/ucma: Fix locking for ctx->events_reported
  RDMA/ucma: Add missing locking around rdma_leave_multicast()
  RDMA/ucma: Change backlog into an atomic
  RDMA/ucma: Narrow file->mut in ucma_event_handler()
  RDMA/ucma: Rework how new connections are passed through event
    delivery
  RDMA/ucma: Remove closing and the close_wq

 drivers/infiniband/core/cma.c  |  25 +-
 drivers/infiniband/core/ucma.c | 444 +++++++++++++++------------------
 include/rdma/rdma_cm.h         |   5 +
 3 files changed, 226 insertions(+), 248 deletions(-)

--
2.26.2

Re: [PATCH rdma-next 00/14] Cleanup locking and events in ucma

[Jason Gunthorpe]

On Tue, Aug 18, 2020 at 03:05:12PM +0300, Leon Romanovsky wrote:
> From: Leon Romanovsky <leonro@nvidia.com>
> 
> >From Jason:
> 
> Rework how the uevents for new connections are handled so all the locking
> ends up simpler and a work queue can be removed. This should also speed up
> destruction of ucma_context's as a flush_workqueue() was replaced with
> cancel_work_sync().
> 
> The simpler locking comes from narrowing what file->mut covers and moving
> other data to other locks, particularly by injecting the handler_mutex
> from the RDMA CM core as a construct available to ULPs. The handler_mutex
> directly prevents handlers from running without creating any ABBA locking
> problems.
> 
> Fix various error cases and data races caused by missing locking.
> 
> Thanks
> 
> Jason Gunthorpe (14):
>   RDMA/ucma: Fix refcount 0 incr in ucma_get_ctx()
>   RDMA/ucma: Remove unnecessary locking of file->ctx_list in close
>   RDMA/ucma: Consolidate the two destroy flows
>   RDMA/ucma: Fix error cases around ucma_alloc_ctx()
>   RDMA/ucma: Remove mc_list and rely on xarray
>   RDMA/cma: Add missing locking to rdma_accept()
>   RDMA/ucma: Do not use file->mut to lock destroying
>   RDMA/ucma: Fix the locking of ctx->file
>   RDMA/ucma: Fix locking for ctx->events_reported
>   RDMA/ucma: Add missing locking around rdma_leave_multicast()
>   RDMA/ucma: Change backlog into an atomic
>   RDMA/ucma: Narrow file->mut in ucma_event_handler()
>   RDMA/ucma: Rework how new connections are passed through event
>     delivery
>   RDMA/ucma: Remove closing and the close_wq

Applied to for-next

Jason