Merge tag 'nfs-rdma-for-5.7-2' of git://git.linux-nfs.org/projects/anna/linux-nfs

NFSoRDMA Client Fixes for Linux 5.7

Bugfixes:
- Restore wake-up-all to rpcrdma_cm_event_handler()
  - Otherwise the client won't respond to server disconnect requests
- Fix tracepoint use-after-free race
- Fix usage of xdr_stream_encode_item_{present, absent}
  - These functions return a size on success, and not 0

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

Author: Trond Myklebust

include/trace/events/rpcrdma.h

@@ -692,11 +692,10 @@ TRACE_EVENT(xprtrdma_prepsend_failed,
 
 TRACE_EVENT(xprtrdma_post_send,
 	TP_PROTO(
-		const struct rpcrdma_req *req,
-		int status
+		const struct rpcrdma_req *req
 	),
 
-	TP_ARGS(req, status),
+	TP_ARGS(req),
 
 	TP_STRUCT__entry(
 		__field(const void *, req)
@@ -705,7 +704,6 @@ TRACE_EVENT(xprtrdma_post_send,
 		__field(unsigned int, client_id)
 		__field(int, num_sge)
 		__field(int, signaled)
-		__field(int, status)
 	),
 
 	TP_fast_assign(
@@ -718,15 +716,13 @@ TRACE_EVENT(xprtrdma_post_send,
 		__entry->sc = req->rl_sendctx;
 		__entry->num_sge = req->rl_wr.num_sge;
 		__entry->signaled = req->rl_wr.send_flags & IB_SEND_SIGNALED;
-		__entry->status = status;
 	),
 
-	TP_printk("task:%u@%u req=%p sc=%p (%d SGE%s) %sstatus=%d",
+	TP_printk("task:%u@%u req=%p sc=%p (%d SGE%s) %s",
 		__entry->task_id, __entry->client_id,
 		__entry->req, __entry->sc, __entry->num_sge,
 		(__entry->num_sge == 1 ? "" : "s"),
-		(__entry->signaled ? "signaled " : ""),
-		__entry->status
+		(__entry->signaled ? "signaled" : "")
 	)
 );
 

net/sunrpc/xprtrdma/rpc_rdma.c

@@ -388,7 +388,9 @@ static int rpcrdma_encode_read_list(struct rpcrdma_xprt *r_xprt,
 	} while (nsegs);
 
 done:
-	return xdr_stream_encode_item_absent(xdr);
+	if (xdr_stream_encode_item_absent(xdr) < 0)
+		return -EMSGSIZE;
+	return 0;
 }
 
 /* Register and XDR encode the Write list. Supports encoding a list
@@ -454,7 +456,9 @@ static int rpcrdma_encode_write_list(struct rpcrdma_xprt *r_xprt,
 	*segcount = cpu_to_be32(nchunks);
 
 done:
-	return xdr_stream_encode_item_absent(xdr);
+	if (xdr_stream_encode_item_absent(xdr) < 0)
+		return -EMSGSIZE;
+	return 0;
 }
 
 /* Register and XDR encode the Reply chunk. Supports encoding an array
@@ -480,8 +484,11 @@ static int rpcrdma_encode_reply_chunk(struct rpcrdma_xprt *r_xprt,
 	int nsegs, nchunks;
 	__be32 *segcount;
 
-	if (wtype != rpcrdma_replych)
-		return xdr_stream_encode_item_absent(xdr);
+	if (wtype != rpcrdma_replych) {
+		if (xdr_stream_encode_item_absent(xdr) < 0)
+			return -EMSGSIZE;
+		return 0;
+	}
 
 	seg = req->rl_segments;
 	nsegs = rpcrdma_convert_iovs(r_xprt, &rqst->rq_rcv_buf, 0, wtype, seg);

net/sunrpc/xprtrdma/verbs.c

@@ -289,6 +289,7 @@ rpcrdma_cm_event_handler(struct rdma_cm_id *id, struct rdma_cm_event *event)
 	case RDMA_CM_EVENT_DISCONNECTED:
 		ep->re_connect_status = -ECONNABORTED;
 disconnected:
+		xprt_force_disconnect(xprt);
 		return rpcrdma_ep_destroy(ep);
 	default:
 		break;
@@ -1355,8 +1356,8 @@ int rpcrdma_post_sends(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req)
 		--ep->re_send_count;
 	}
 
+	trace_xprtrdma_post_send(req);
 	rc = frwr_send(r_xprt, req);
-	trace_xprtrdma_post_send(req, rc);
 	if (rc)
 		return -ENOTCONN;
 	return 0;