From 15ae1375ea91ae2dee6f12d71a79d8c0a10a30bf Mon Sep 17 00:00:00 2001 From: Bob Pearson Date: Fri, 4 Jun 2021 18:05:59 -0500 Subject: [PATCH] RDMA/rxe: Fix qp reference counting for atomic ops Currently the rdma_rxe driver attempts to protect atomic responder resources by taking a reference to the qp which is only freed when the resource is recycled for a new read or atomic operation. This means that in normal circumstances there is almost always an extra qp reference once an atomic operation has been executed which prevents cleaning up the qp and associated pd and cqs when the qp is destroyed. This patch removes the call to rxe_add_ref() in send_atomic_ack() and the call to rxe_drop_ref() in free_rd_atomic_resource(). If the qp is destroyed while a peer is retrying an atomic op it will cause the operation to fail which is acceptable. Link: https://lore.kernel.org/r/20210604230558.4812-1-rpearsonhpe@gmail.com Reported-by: Zhu Yanjun Fixes: 86af61764151 ("IB/rxe: remove unnecessary skb_clone") Signed-off-by: Bob Pearson Signed-off-by: Jason Gunthorpe --- drivers/infiniband/sw/rxe/rxe_qp.c | 1 - drivers/infiniband/sw/rxe/rxe_resp.c | 2 -- 2 files changed, 3 deletions(-) diff --git a/drivers/infiniband/sw/rxe/rxe_qp.c b/drivers/infiniband/sw/rxe/rxe_qp.c index a925686..3dd9e96 100644 --- a/drivers/infiniband/sw/rxe/rxe_qp.c +++ b/drivers/infiniband/sw/rxe/rxe_qp.c @@ -136,7 +136,6 @@ static void free_rd_atomic_resources(struct rxe_qp *qp) void free_rd_atomic_resource(struct rxe_qp *qp, struct resp_res *res) { if (res->type == RXE_ATOMIC_MASK) { - rxe_drop_ref(qp); kfree_skb(res->atomic.skb); } else if (res->type == RXE_READ_MASK) { if (res->read.mr) diff --git a/drivers/infiniband/sw/rxe/rxe_resp.c b/drivers/infiniband/sw/rxe/rxe_resp.c index 08f0422..9c0ce1a 100644 --- a/drivers/infiniband/sw/rxe/rxe_resp.c +++ b/drivers/infiniband/sw/rxe/rxe_resp.c @@ -989,8 +989,6 @@ static int send_atomic_ack(struct rxe_qp *qp, struct rxe_pkt_info *pkt, goto out; } - rxe_add_ref(qp); - res = &qp->resp.resources[qp->resp.res_head]; free_rd_atomic_resource(qp, res); rxe_advance_resp_resource(qp); -- 2.7.4