From: Bob Pearson <rpearsonhpe@gmail.com>
Date: Wed, 20 Apr 2022 20:40:36 -0500
Subject: RDMA/rxe: Check rxe_get() return value
Patch-mainline: v5.19-rc1
Git-commit: 4e05a4b329e9416e5aded022feacde4385148f21
References: jsc#PED-1111
In the tasklets (completer, responder, and requester) check the return
value from rxe_get() to detect failures to get a reference. This only
occurs if the qp has had its reference count drop to zero which indicates
that it no longer should be used.
The ref is never 0 today because the tasklets are flushed before the ref
is dropped. The next patch changes this so that the ref is dropped then
the tasklets are flushed.
Link: https://lore.kernel.org/r/20220421014042.26985-4-rpearsonhpe@gmail.com
Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
drivers/infiniband/sw/rxe/rxe_comp.c | 3 ++-
drivers/infiniband/sw/rxe/rxe_req.c | 3 ++-
drivers/infiniband/sw/rxe/rxe_resp.c | 3 ++-
3 files changed, 6 insertions(+), 3 deletions(-)
--- a/drivers/infiniband/sw/rxe/rxe_comp.c
+++ b/drivers/infiniband/sw/rxe/rxe_comp.c
@@ -562,7 +562,8 @@ int rxe_completer(void *arg)
enum comp_state state;
int ret = 0;
- rxe_get(qp);
+ if (!rxe_get(qp))
+ return -EAGAIN;
if (!qp->valid || qp->req.state == QP_STATE_ERROR ||
qp->req.state == QP_STATE_RESET) {
--- a/drivers/infiniband/sw/rxe/rxe_req.c
+++ b/drivers/infiniband/sw/rxe/rxe_req.c
@@ -606,7 +606,8 @@ int rxe_requester(void *arg)
struct rxe_ah *ah;
struct rxe_av *av;
- rxe_get(qp);
+ if (!rxe_get(qp))
+ return -EAGAIN;
next_wqe:
if (unlikely(!qp->valid || qp->req.state == QP_STATE_ERROR))
--- a/drivers/infiniband/sw/rxe/rxe_resp.c
+++ b/drivers/infiniband/sw/rxe/rxe_resp.c
@@ -1262,7 +1262,8 @@ int rxe_responder(void *arg)
struct rxe_pkt_info *pkt = NULL;
int ret = 0;
- rxe_get(qp);
+ if (!rxe_get(qp))
+ return -EAGAIN;
qp->resp.aeth_syndrome = AETH_ACK_UNLIMITED;