Merge tag 'nfs-for-4.7-1' of git://git.linux-nfs.org/projects/anna/linux-nfs

Pull NFS client updates from Anna Schumaker:
 "Highlights include:

  Features:
   - Add support for the NFS v4.2 COPY operation
   - Add support for NFS/RDMA over IPv6

  Bugfixes and cleanups:
   - Avoid race that crashes nfs_init_commit()
   - Fix oops in callback path
   - Fix LOCK/OPEN race when unlinking an open file
   - Choose correct stateids when using delegations in setattr, read and
     write
   - Don't send empty SETATTR after OPEN_CREATE
   - xprtrdma: Prevent server from writing a reply into memory client
     has released
   - xprtrdma: Support using Read list and Reply chunk in one RPC call"

* tag 'nfs-for-4.7-1' of git://git.linux-nfs.org/projects/anna/linux-nfs: (61 commits)
  pnfs: pnfs_update_layout needs to consider if strict iomode checking is on
  nfs/flexfiles: Use the layout segment for reading unless it a IOMODE_RW and reading is disabled
  nfs/flexfiles: Helper function to detect FF_FLAGS_NO_READ_IO
  nfs: avoid race that crashes nfs_init_commit
  NFS: checking for NULL instead of IS_ERR() in nfs_commit_file()
  pnfs: make pnfs_layout_process more robust
  pnfs: rework LAYOUTGET retry handling
  pnfs: lift retry logic from send_layoutget to pnfs_update_layout
  pnfs: fix bad error handling in send_layoutget
  flexfiles: add kerneldoc header to nfs4_ff_layout_prepare_ds
  flexfiles: remove pointless setting of NFS_LAYOUT_RETURN_REQUESTED
  pnfs: only tear down lsegs that precede seqid in LAYOUTRETURN args
  pnfs: keep track of the return sequence number in pnfs_layout_hdr
  pnfs: record sequence in pnfs_layout_segment when it's created
  pnfs: don't merge new ff lsegs with ones that have LAYOUTRETURN bit set
  pNFS/flexfiles: When initing reads or writes, we might have to retry connecting to DSes
  pNFS/flexfiles: When checking for available DSes, conditionally check for MDS io
  pNFS/flexfile: Fix erroneous fall back to read/write through the MDS
  NFS: Reclaim writes via writepage are opportunistic
  NFSv4: Use the right stateid for delegations in setattr, read and write
  ...

1 files changed, 17 insertions, 61 deletions

diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index f5ed9f982cd7..b044d98a1370 100644
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -203,15 +203,6 @@ out_fail:
 	goto out_schedule;
 }
 
-static void
-rpcrdma_flush_cqs(struct rpcrdma_ep *ep)
-{
-	struct ib_wc wc;
-
-	while (ib_poll_cq(ep->rep_attr.recv_cq, 1, &wc) > 0)
-		rpcrdma_receive_wc(NULL, &wc);
-}
-
 static int
 rpcrdma_conn_upcall(struct rdma_cm_id *id, struct rdma_cm_event *event)
 {
@@ -374,23 +365,6 @@ out:
 }
 
 /*
- * Drain any cq, prior to teardown.
- */
-static void
-rpcrdma_clean_cq(struct ib_cq *cq)
-{
-	struct ib_wc wc;
-	int count = 0;
-
-	while (1 == ib_poll_cq(cq, 1, &wc))
-		++count;
-
-	if (count)
-		dprintk("RPC:       %s: flushed %d events (last 0x%x)\n",
-			__func__, count, wc.opcode);
-}
-
-/*
  * Exported functions.
  */
 
@@ -459,7 +433,6 @@ rpcrdma_ia_open(struct rpcrdma_xprt *xprt, struct sockaddr *addr, int memreg)
 	dprintk("RPC:       %s: memory registration strategy is '%s'\n",
 		__func__, ia->ri_ops->ro_displayname);
 
-	rwlock_init(&ia->ri_qplock);
 	return 0;
 
 out3:
@@ -515,7 +488,7 @@ rpcrdma_ep_create(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia,
 			__func__);
 		return -ENOMEM;
 	}
-	max_qp_wr = ia->ri_device->attrs.max_qp_wr - RPCRDMA_BACKWARD_WRS;
+	max_qp_wr = ia->ri_device->attrs.max_qp_wr - RPCRDMA_BACKWARD_WRS - 1;
 
 	/* check provider's send/recv wr limits */
 	if (cdata->max_requests > max_qp_wr)
@@ -526,11 +499,13 @@ rpcrdma_ep_create(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia,
 	ep->rep_attr.srq = NULL;
 	ep->rep_attr.cap.max_send_wr = cdata->max_requests;
 	ep->rep_attr.cap.max_send_wr += RPCRDMA_BACKWARD_WRS;
+	ep->rep_attr.cap.max_send_wr += 1;	/* drain cqe */
 	rc = ia->ri_ops->ro_open(ia, ep, cdata);
 	if (rc)
 		return rc;
 	ep->rep_attr.cap.max_recv_wr = cdata->max_requests;
 	ep->rep_attr.cap.max_recv_wr += RPCRDMA_BACKWARD_WRS;
+	ep->rep_attr.cap.max_recv_wr += 1;	/* drain cqe */
 	ep->rep_attr.cap.max_send_sge = RPCRDMA_MAX_IOVS;
 	ep->rep_attr.cap.max_recv_sge = 1;
 	ep->rep_attr.cap.max_inline_data = 0;
@@ -578,6 +553,7 @@ rpcrdma_ep_create(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia,
 	ep->rep_attr.recv_cq = recvcq;
 
 	/* Initialize cma parameters */
+	memset(&ep->rep_remote_cma, 0, sizeof(ep->rep_remote_cma));
 
 	/* RPC/RDMA does not use private data */
 	ep->rep_remote_cma.private_data = NULL;
@@ -591,7 +567,16 @@ rpcrdma_ep_create(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia,
 		ep->rep_remote_cma.responder_resources =
 						ia->ri_device->attrs.max_qp_rd_atom;
 
-	ep->rep_remote_cma.retry_count = 7;
+	/* Limit transport retries so client can detect server
+	 * GID changes quickly. RPC layer handles re-establishing
+	 * transport connection and retransmission.
+	 */
+	ep->rep_remote_cma.retry_count = 6;
+
+	/* RPC-over-RDMA handles its own flow control. In addition,
+	 * make all RNR NAKs visible so we know that RPC-over-RDMA
+	 * flow control is working correctly (no NAKs should be seen).
+	 */
 	ep->rep_remote_cma.flow_control = 0;
 	ep->rep_remote_cma.rnr_retry_count = 0;
 
@@ -622,13 +607,8 @@ rpcrdma_ep_destroy(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
 
 	cancel_delayed_work_sync(&ep->rep_connect_worker);
 
-	if (ia->ri_id->qp)
-		rpcrdma_ep_disconnect(ep, ia);
-
-	rpcrdma_clean_cq(ep->rep_attr.recv_cq);
-	rpcrdma_clean_cq(ep->rep_attr.send_cq);
-
 	if (ia->ri_id->qp) {
+		rpcrdma_ep_disconnect(ep, ia);
 		rdma_destroy_qp(ia->ri_id);
 		ia->ri_id->qp = NULL;
 	}
@@ -659,7 +639,6 @@ retry:
 		dprintk("RPC:       %s: reconnecting...\n", __func__);
 
 		rpcrdma_ep_disconnect(ep, ia);
-		rpcrdma_flush_cqs(ep);
 
 		xprt = container_of(ia, struct rpcrdma_xprt, rx_ia);
 		id = rpcrdma_create_id(xprt, ia,
@@ -692,10 +671,8 @@ retry:
 			goto out;
 		}
 
-		write_lock(&ia->ri_qplock);
 		old = ia->ri_id;
 		ia->ri_id = id;
-		write_unlock(&ia->ri_qplock);
 
 		rdma_destroy_qp(old);
 		rpcrdma_destroy_id(old);
@@ -785,7 +762,6 @@ rpcrdma_ep_disconnect(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
 {
 	int rc;
 
-	rpcrdma_flush_cqs(ep);
 	rc = rdma_disconnect(ia->ri_id);
 	if (!rc) {
 		/* returns without wait if not connected */
@@ -797,6 +773,8 @@ rpcrdma_ep_disconnect(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
 		dprintk("RPC:       %s: rdma_disconnect %i\n", __func__, rc);
 		ep->rep_connected = rc;
 	}
+
+	ib_drain_qp(ia->ri_id->qp);
 }
 
 struct rpcrdma_req *
@@ -1271,25 +1249,3 @@ out_rc:
 	rpcrdma_recv_buffer_put(rep);
 	return rc;
 }
-
-/* How many chunk list items fit within our inline buffers?
- */
-unsigned int
-rpcrdma_max_segments(struct rpcrdma_xprt *r_xprt)
-{
-	struct rpcrdma_create_data_internal *cdata = &r_xprt->rx_data;
-	int bytes, segments;
-
-	bytes = min_t(unsigned int, cdata->inline_wsize, cdata->inline_rsize);
-	bytes -= RPCRDMA_HDRLEN_MIN;
-	if (bytes < sizeof(struct rpcrdma_segment) * 2) {
-		pr_warn("RPC:       %s: inline threshold too small\n",
-			__func__);
-		return 0;
-	}
-
-	segments = 1 << (fls(bytes / sizeof(struct rpcrdma_segment)) - 1);
-	dprintk("RPC:       %s: max chunk list size = %d segments\n",
-		__func__, segments);
-	return segments;
-}