xprtrdma: Ensure ia->ri_id->qp is not NULL when reconnecting (ec62f40d) · Commits · 戴 / test

Devesh Sharma <Devesh.Sharma@Emulex.Com> 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@oracle.com> Signed-off-by:

Anna Schumaker <Anna.Schumaker@Netapp.com>

net/sunrpc/xprtrdma/verbs.c

+20 −9

Original line number	Diff line number	Diff line
		@@ -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;
		}

		} 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);
		goto out;
		/* do not update ep->rep_connected */
		return -ENETUNREACH;
		}
		}

		/* XXX Tavor device performs badly with 2K MTU! */

Admin message