Devesh Sharma <Devesh.Sharma@xxxxxxxxxx> reports that after a
disconnect, his HCA is failing to create a fresh QP, leaving
ia_ri->ri_id->qp set to NULL. But xprtrdma still allows RPCs to
wake up and post LOCAL_INV as they exit, causing an oops.
rpcrdma_ep_connect() is allowing the wake-up by leaking the QP
creation error code (-EPERM in this case) to the RPC client's
generic layer. xprt_connect_status() does not recognize -EPERM, so
it kills pending RPC tasks immediately rather than retrying the
connect.
Re-arrange the QP creation logic so that when it fails on reconnect,
it leaves ->qp with the old QP rather than NULL. If pending RPC
tasks wake and exit, LOCAL_INV work requests will flush rather than
oops.
On initial connect, leaving ->qp == NULL is OK, since there are no
pending RPCs that might use ->qp. But be sure not to try to destroy
a NULL QP when rpcrdma_ep_connect() is retried.
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
Hi-
I tested with fault injection, but I've probably missed a corner
case or two. Please test and review. Thanks!
net/sunrpc/xprtrdma/verbs.c | 29 ++++++++++++++++++++---------
1 files changed, 20 insertions(+), 9 deletions(-)
diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index 85d4987..0f3ec65 100644
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -867,6 +867,7 @@ rpcrdma_ep_connect(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
if (ep->rep_connected != 0) {
struct rpcrdma_xprt *xprt;
retry:
+ dprintk("RPC: %s: reconnecting...\n", __func__);
rc = rpcrdma_ep_disconnect(ep, ia);
if (rc && rc != -ENOTCONN)
dprintk("RPC: %s: rpcrdma_ep_disconnect"
@@ -879,7 +880,7 @@ retry:
id = rpcrdma_create_id(xprt, ia,
(struct sockaddr *)&xprt->rx_data.addr);
if (IS_ERR(id)) {
- rc = PTR_ERR(id);
+ rc = -EHOSTUNREACH;
goto out;
}
/* TEMP TEMP TEMP - fail if new device:
@@ -893,20 +894,30 @@ retry:
printk("RPC: %s: can't reconnect on "
"different device!\n", __func__);
rdma_destroy_id(id);
- rc = -ENETDOWN;
+ rc = -ENETUNREACH;
goto out;
}
/* END TEMP */
+ rc = rdma_create_qp(id, ia->ri_pd, &ep->rep_attr);
+ if (rc) {
+ dprintk("RPC: %s: rdma_create_qp failed %i\n",
+ __func__, rc);
+ rdma_destroy_id(id);
+ rc = -ENETUNREACH;
+ goto out;
+ }
rdma_destroy_qp(ia->ri_id);
rdma_destroy_id(ia->ri_id);
ia->ri_id = id;
- }
-
- rc = rdma_create_qp(ia->ri_id, ia->ri_pd, &ep->rep_attr);
- if (rc) {
- dprintk("RPC: %s: rdma_create_qp failed %i\n",
- __func__, rc);
- goto out;
+ } else {
+ dprintk("RPC: %s: connecting...\n", __func__);
+ rc = rdma_create_qp(ia->ri_id, ia->ri_pd, &ep->rep_attr);
+ if (rc) {
+ dprintk("RPC: %s: rdma_create_qp failed %i\n",
+ __func__, rc);
+ /* do not update ep->rep_connected */
+ return -ENETUNREACH;
+ }
}
/* XXX Tavor device performs badly with 2K MTU! */
--
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