linux/drivers/infiniband
Roland Dreier c761611811 IB/cm: Fix sleeping in atomic when RoCE is used
A couple of places in the CM do

    spin_lock_irq(&cm_id_priv->lock);
    ...
    if (cm_alloc_response_msg(work->port, work->mad_recv_wc, &msg))

However when the underlying transport is RoCE, this leads to a sleeping function
being called with the lock held - the callchain is

    cm_alloc_response_msg() ->
      ib_create_ah_from_wc() ->
        ib_init_ah_from_wc() ->
          rdma_addr_find_l2_eth_by_grh() ->
            rdma_resolve_ip()

and rdma_resolve_ip() starts out by doing

    req = kzalloc(sizeof *req, GFP_KERNEL);

not to mention rdma_addr_find_l2_eth_by_grh() doing

    wait_for_completion(&ctx.comp);

to wait for the task that rdma_resolve_ip() queues up.

Fix this by moving the AH creation out of the lock.

Signed-off-by: Roland Dreier <roland@purestorage.com>
Reviewed-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
2017-08-31 08:35:07 -04:00
..
core IB/cm: Fix sleeping in atomic when RoCE is used 2017-08-31 08:35:07 -04:00
hw IB/mlx5: Support IB_SRQT_TM 2017-08-29 08:30:20 -04:00
sw IB/rxe: Handle NETDEV_CHANGE events 2017-08-28 19:12:36 -04:00
ulp Merge branch 'mellanox' into k.o/for-next 2017-08-24 20:25:15 -04:00
Kconfig IB/opa-vnic: Virtual Network Interface Controller (VNIC) netdev 2017-04-20 12:01:38 -04:00
Makefile IB/rdmavt: Create module framework and handle driver registration 2016-03-10 20:37:04 -05:00