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>
1 file changed