This is a note to let you know that I've just added the patch titled RDMA/cma: Remove dead code for kernel rdmacm multicast to the 4.19-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: rdma-cma-remove-dead-code-for-kernel-rdmacm-multicas.patch and it can be found in the queue-4.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 7d5efa58e36ee7c2a4c5d468ec0f8d7b70bb8bf1 Author: Jason Gunthorpe <jgg@xxxxxxxxxx> Date: Wed Sep 2 11:11:20 2020 +0300 RDMA/cma: Remove dead code for kernel rdmacm multicast [ Upstream commit 1bb5091def706732c749df9aae45fbca003696f2 ] There is no kernel user of RDMA CM multicast so this code managing the multicast subscription of the kernel-only internal QP is dead. Remove it. This makes the bug fixes in the next patches much simpler. Link: https://lore.kernel.org/r/20200902081122.745412-7-leon@xxxxxxxxxx Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxx> Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c index 1f14cd4ce3db5..65c15114cbe7a 100644 --- a/drivers/infiniband/core/cma.c +++ b/drivers/infiniband/core/cma.c @@ -4020,16 +4020,6 @@ static int cma_ib_mc_handler(int status, struct ib_sa_multicast *multicast) else pr_debug_ratelimited("RDMA CM: MULTICAST_ERROR: failed to join multicast. status %d\n", status); - mutex_lock(&id_priv->qp_mutex); - if (!status && id_priv->id.qp) { - status = ib_attach_mcast(id_priv->id.qp, &multicast->rec.mgid, - be16_to_cpu(multicast->rec.mlid)); - if (status) - pr_debug_ratelimited("RDMA CM: MULTICAST_ERROR: failed to attach QP. status %d\n", - status); - } - mutex_unlock(&id_priv->qp_mutex); - event.status = status; event.param.ud.private_data = mc->context; if (!status) { @@ -4283,6 +4273,10 @@ int rdma_join_multicast(struct rdma_cm_id *id, struct sockaddr *addr, struct cma_multicast *mc; int ret; + /* Not supported for kernel QPs */ + if (WARN_ON(id->qp)) + return -EINVAL; + if (!id->device) return -EINVAL; @@ -4337,11 +4331,6 @@ void rdma_leave_multicast(struct rdma_cm_id *id, struct sockaddr *addr) list_del(&mc->list); spin_unlock_irq(&id_priv->lock); - if (id->qp) - ib_detach_mcast(id->qp, - &mc->multicast.ib->rec.mgid, - be16_to_cpu(mc->multicast.ib->rec.mlid)); - BUG_ON(id_priv->cma_dev->device != id->device); if (rdma_cap_ib_mcast(id->device, id->port_num)) {