Linux-libre 4.5-gnu

14 files changed, 1004 insertions, 269 deletions

diff --git a/net/sunrpc/xprtrdma/Makefile b/net/sunrpc/xprtrdma/Makefile
index 33f99d300..dc9f3b513 100644
--- a/net/sunrpc/xprtrdma/Makefile
+++ b/net/sunrpc/xprtrdma/Makefile
@@ -2,7 +2,7 @@ obj-$(CONFIG_SUNRPC_XPRT_RDMA) += rpcrdma.o
 
 rpcrdma-y := transport.o rpc_rdma.o verbs.o \
 	fmr_ops.o frwr_ops.o physical_ops.o \
-	svc_rdma.o svc_rdma_transport.o \
+	svc_rdma.o svc_rdma_backchannel.o svc_rdma_transport.o \
 	svc_rdma_marshal.o svc_rdma_sendto.o svc_rdma_recvfrom.o \
 	module.o
 rpcrdma-$(CONFIG_SUNRPC_BACKCHANNEL) += backchannel.o
diff --git a/net/sunrpc/xprtrdma/backchannel.c b/net/sunrpc/xprtrdma/backchannel.c
index 2dcb44f69..2dcd7640e 100644
--- a/net/sunrpc/xprtrdma/backchannel.c
+++ b/net/sunrpc/xprtrdma/backchannel.c
@@ -15,7 +15,7 @@
 # define RPCDBG_FACILITY	RPCDBG_TRANS
 #endif
 
-#define RPCRDMA_BACKCHANNEL_DEBUG
+#undef RPCRDMA_BACKCHANNEL_DEBUG
 
 static void rpcrdma_bc_free_rqst(struct rpcrdma_xprt *r_xprt,
 				 struct rpc_rqst *rqst)
@@ -42,8 +42,8 @@ static int rpcrdma_bc_setup_rqst(struct rpcrdma_xprt *r_xprt,
 	size_t size;
 
 	req = rpcrdma_create_req(r_xprt);
-	if (!req)
-		return -ENOMEM;
+	if (IS_ERR(req))
+		return PTR_ERR(req);
 	req->rl_backchannel = true;
 
 	size = RPCRDMA_INLINE_WRITE_THRESHOLD(rqst);
@@ -84,9 +84,7 @@ out_fail:
 static int rpcrdma_bc_setup_reps(struct rpcrdma_xprt *r_xprt,
 				 unsigned int count)
 {
-	struct rpcrdma_buffer *buffers = &r_xprt->rx_buf;
 	struct rpcrdma_rep *rep;
-	unsigned long flags;
 	int rc = 0;
 
 	while (count--) {
@@ -98,9 +96,7 @@ static int rpcrdma_bc_setup_reps(struct rpcrdma_xprt *r_xprt,
 			break;
 		}
 
-		spin_lock_irqsave(&buffers->rb_lock, flags);
-		list_add(&rep->rr_list, &buffers->rb_recv_bufs);
-		spin_unlock_irqrestore(&buffers->rb_lock, flags);
+		rpcrdma_recv_buffer_put(rep);
 	}
 
 	return rc;
@@ -140,6 +136,7 @@ int xprt_rdma_bc_setup(struct rpc_xprt *xprt, unsigned int reqs)
 			       __func__);
 			goto out_free;
 		}
+		dprintk("RPC:       %s: new rqst %p\n", __func__, rqst);
 
 		rqst->rq_xprt = &r_xprt->rx_xprt;
 		INIT_LIST_HEAD(&rqst->rq_list);
@@ -220,12 +217,14 @@ int rpcrdma_bc_marshal_reply(struct rpc_rqst *rqst)
 
 	rpclen = rqst->rq_svec[0].iov_len;
 
+#ifdef RPCRDMA_BACKCHANNEL_DEBUG
 	pr_info("RPC:       %s: rpclen %zd headerp 0x%p lkey 0x%x\n",
 		__func__, rpclen, headerp, rdmab_lkey(req->rl_rdmabuf));
 	pr_info("RPC:       %s: RPC/RDMA: %*ph\n",
 		__func__, (int)RPCRDMA_HDRLEN_MIN, headerp);
 	pr_info("RPC:       %s:      RPC: %*ph\n",
 		__func__, (int)rpclen, rqst->rq_svec[0].iov_base);
+#endif
 
 	req->rl_send_iov[0].addr = rdmab_addr(req->rl_rdmabuf);
 	req->rl_send_iov[0].length = RPCRDMA_HDRLEN_MIN;
@@ -269,6 +268,9 @@ void xprt_rdma_bc_free_rqst(struct rpc_rqst *rqst)
 {
 	struct rpc_xprt *xprt = rqst->rq_xprt;
 
+	dprintk("RPC:       %s: freeing rqst %p (req %p)\n",
+		__func__, rqst, rpcr_to_rdmar(rqst));
+
 	smp_mb__before_atomic();
 	WARN_ON_ONCE(!test_bit(RPC_BC_PA_IN_USE, &rqst->rq_bc_pa_state));
 	clear_bit(RPC_BC_PA_IN_USE, &rqst->rq_bc_pa_state);
@@ -333,14 +335,14 @@ void rpcrdma_bc_receive_call(struct rpcrdma_xprt *r_xprt,
 				struct rpc_rqst, rq_bc_pa_list);
 	list_del(&rqst->rq_bc_pa_list);
 	spin_unlock(&xprt->bc_pa_lock);
-#ifdef RPCRDMA_BACKCHANNEL_DEBUG
-	pr_info("RPC:       %s: using rqst %p\n", __func__, rqst);
-#endif
+	dprintk("RPC:       %s: using rqst %p\n", __func__, rqst);
 
 	/* Prepare rqst */
 	rqst->rq_reply_bytes_recvd = 0;
 	rqst->rq_bytes_sent = 0;
 	rqst->rq_xid = headerp->rm_xid;
+
+	rqst->rq_private_buf.len = size;
 	set_bit(RPC_BC_PA_IN_USE, &rqst->rq_bc_pa_state);
 
 	buf = &rqst->rq_rcv_buf;
@@ -355,10 +357,8 @@ void rpcrdma_bc_receive_call(struct rpcrdma_xprt *r_xprt,
 	 * direction reply.
 	 */
 	req = rpcr_to_rdmar(rqst);
-#ifdef RPCRDMA_BACKCHANNEL_DEBUG
-	pr_info("RPC:       %s: attaching rep %p to req %p\n",
+	dprintk("RPC:       %s: attaching rep %p to req %p\n",
 		__func__, rep, req);
-#endif
 	req->rl_reply = rep;
 
 	/* Defeat the retransmit detection logic in send_request */
diff --git a/net/sunrpc/xprtrdma/fmr_ops.c b/net/sunrpc/xprtrdma/fmr_ops.c
index f1e8dafbd..c14f3a4bf 100644
--- a/net/sunrpc/xprtrdma/fmr_ops.c
+++ b/net/sunrpc/xprtrdma/fmr_ops.c
@@ -179,6 +179,69 @@ out_maperr:
 	return rc;
 }
 
+static void
+__fmr_dma_unmap(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg)
+{
+	struct ib_device *device = r_xprt->rx_ia.ri_device;
+	struct rpcrdma_mw *mw = seg->rl_mw;
+	int nsegs = seg->mr_nsegs;
+
+	seg->rl_mw = NULL;
+
+	while (nsegs--)
+		rpcrdma_unmap_one(device, seg++);
+
+	rpcrdma_put_mw(r_xprt, mw);
+}
+
+/* Invalidate all memory regions that were registered for "req".
+ *
+ * Sleeps until it is safe for the host CPU to access the
+ * previously mapped memory regions.
+ */
+static void
+fmr_op_unmap_sync(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req)
+{
+	struct rpcrdma_mr_seg *seg;
+	unsigned int i, nchunks;
+	struct rpcrdma_mw *mw;
+	LIST_HEAD(unmap_list);
+	int rc;
+
+	dprintk("RPC:       %s: req %p\n", __func__, req);
+
+	/* ORDER: Invalidate all of the req's MRs first
+	 *
+	 * ib_unmap_fmr() is slow, so use a single call instead
+	 * of one call per mapped MR.
+	 */
+	for (i = 0, nchunks = req->rl_nchunks; nchunks; nchunks--) {
+		seg = &req->rl_segments[i];
+		mw = seg->rl_mw;
+
+		list_add(&mw->r.fmr.fmr->list, &unmap_list);
+
+		i += seg->mr_nsegs;
+	}
+	rc = ib_unmap_fmr(&unmap_list);
+	if (rc)
+		pr_warn("%s: ib_unmap_fmr failed (%i)\n", __func__, rc);
+
+	/* ORDER: Now DMA unmap all of the req's MRs, and return
+	 * them to the free MW list.
+	 */
+	for (i = 0, nchunks = req->rl_nchunks; nchunks; nchunks--) {
+		seg = &req->rl_segments[i];
+
+		__fmr_dma_unmap(r_xprt, seg);
+
+		i += seg->mr_nsegs;
+		seg->mr_nsegs = 0;
+	}
+
+	req->rl_nchunks = 0;
+}
+
 /* Use the ib_unmap_fmr() verb to prevent further remote
  * access via RDMA READ or RDMA WRITE.
  */
@@ -231,6 +294,7 @@ fmr_op_destroy(struct rpcrdma_buffer *buf)
 
 const struct rpcrdma_memreg_ops rpcrdma_fmr_memreg_ops = {
 	.ro_map				= fmr_op_map,
+	.ro_unmap_sync			= fmr_op_unmap_sync,
 	.ro_unmap			= fmr_op_unmap,
 	.ro_open			= fmr_op_open,
 	.ro_maxpages			= fmr_op_maxpages,
diff --git a/net/sunrpc/xprtrdma/frwr_ops.c b/net/sunrpc/xprtrdma/frwr_ops.c
index 88cf9e726..e16567389 100644
--- a/net/sunrpc/xprtrdma/frwr_ops.c
+++ b/net/sunrpc/xprtrdma/frwr_ops.c
@@ -190,12 +190,11 @@ static int
 frwr_op_open(struct rpcrdma_ia *ia, struct rpcrdma_ep *ep,
 	     struct rpcrdma_create_data_internal *cdata)
 {
-	struct ib_device_attr *devattr = &ia->ri_devattr;
 	int depth, delta;
 
 	ia->ri_max_frmr_depth =
 			min_t(unsigned int, RPCRDMA_MAX_DATA_SEGS,
-			      devattr->max_fast_reg_page_list_len);
+			      ia->ri_device->attrs.max_fast_reg_page_list_len);
 	dprintk("RPC:       %s: device's max FR page list len = %u\n",
 		__func__, ia->ri_max_frmr_depth);
 
@@ -222,8 +221,8 @@ frwr_op_open(struct rpcrdma_ia *ia, struct rpcrdma_ep *ep,
 	}
 
 	ep->rep_attr.cap.max_send_wr *= depth;
-	if (ep->rep_attr.cap.max_send_wr > devattr->max_qp_wr) {
-		cdata->max_requests = devattr->max_qp_wr / depth;
+	if (ep->rep_attr.cap.max_send_wr > ia->ri_device->attrs.max_qp_wr) {
+		cdata->max_requests = ia->ri_device->attrs.max_qp_wr / depth;
 		if (!cdata->max_requests)
 			return -EINVAL;
 		ep->rep_attr.cap.max_send_wr = cdata->max_requests *
@@ -245,12 +244,14 @@ frwr_op_maxpages(struct rpcrdma_xprt *r_xprt)
 		     rpcrdma_max_segments(r_xprt) * ia->ri_max_frmr_depth);
 }
 
-/* If FAST_REG or LOCAL_INV failed, indicate the frmr needs to be reset. */
+/* If FAST_REG or LOCAL_INV failed, indicate the frmr needs
+ * to be reset.
+ *
+ * WARNING: Only wr_id and status are reliable at this point
+ */
 static void
-frwr_sendcompletion(struct ib_wc *wc)
+__frwr_sendcompletion_flush(struct ib_wc *wc, struct rpcrdma_mw *r)
 {
-	struct rpcrdma_mw *r;
-
 	if (likely(wc->status == IB_WC_SUCCESS))
 		return;
 
@@ -261,9 +262,23 @@ frwr_sendcompletion(struct ib_wc *wc)
 	else
 		pr_warn("RPC:       %s: frmr %p error, status %s (%d)\n",
 			__func__, r, ib_wc_status_msg(wc->status), wc->status);
+
 	r->r.frmr.fr_state = FRMR_IS_STALE;
 }
 
+static void
+frwr_sendcompletion(struct ib_wc *wc)
+{
+	struct rpcrdma_mw *r = (struct rpcrdma_mw *)(unsigned long)wc->wr_id;
+	struct rpcrdma_frmr *f = &r->r.frmr;
+
+	if (unlikely(wc->status != IB_WC_SUCCESS))
+		__frwr_sendcompletion_flush(wc, r);
+
+	if (f->fr_waiter)
+		complete(&f->fr_linv_done);
+}
+
 static int
 frwr_op_init(struct rpcrdma_xprt *r_xprt)
 {
@@ -319,7 +334,7 @@ frwr_op_map(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg,
 	struct rpcrdma_mw *mw;
 	struct rpcrdma_frmr *frmr;
 	struct ib_mr *mr;
-	struct ib_reg_wr reg_wr;
+	struct ib_reg_wr *reg_wr;
 	struct ib_send_wr *bad_wr;
 	int rc, i, n, dma_nents;
 	u8 key;
@@ -335,7 +350,9 @@ frwr_op_map(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg,
 	} while (mw->r.frmr.fr_state != FRMR_IS_INVALID);
 	frmr = &mw->r.frmr;
 	frmr->fr_state = FRMR_IS_VALID;
+	frmr->fr_waiter = false;
 	mr = frmr->fr_mr;
+	reg_wr = &frmr->fr_regwr;
 
 	if (nsegs > ia->ri_max_frmr_depth)
 		nsegs = ia->ri_max_frmr_depth;
@@ -381,19 +398,19 @@ frwr_op_map(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg,
 	key = (u8)(mr->rkey & 0x000000FF);
 	ib_update_fast_reg_key(mr, ++key);
 
-	reg_wr.wr.next = NULL;
-	reg_wr.wr.opcode = IB_WR_REG_MR;
-	reg_wr.wr.wr_id = (uintptr_t)mw;
-	reg_wr.wr.num_sge = 0;
-	reg_wr.wr.send_flags = 0;
-	reg_wr.mr = mr;
-	reg_wr.key = mr->rkey;
-	reg_wr.access = writing ?
-			IB_ACCESS_REMOTE_WRITE | IB_ACCESS_LOCAL_WRITE :
-			IB_ACCESS_REMOTE_READ;
+	reg_wr->wr.next = NULL;
+	reg_wr->wr.opcode = IB_WR_REG_MR;
+	reg_wr->wr.wr_id = (uintptr_t)mw;
+	reg_wr->wr.num_sge = 0;
+	reg_wr->wr.send_flags = 0;
+	reg_wr->mr = mr;
+	reg_wr->key = mr->rkey;
+	reg_wr->access = writing ?
+			 IB_ACCESS_REMOTE_WRITE | IB_ACCESS_LOCAL_WRITE :
+			 IB_ACCESS_REMOTE_READ;
 
 	DECR_CQCOUNT(&r_xprt->rx_ep);
-	rc = ib_post_send(ia->ri_id->qp, &reg_wr.wr, &bad_wr);
+	rc = ib_post_send(ia->ri_id->qp, &reg_wr->wr, &bad_wr);
 	if (rc)
 		goto out_senderr;
 
@@ -413,6 +430,116 @@ out_senderr:
 	return rc;
 }
 
+static struct ib_send_wr *
+__frwr_prepare_linv_wr(struct rpcrdma_mr_seg *seg)
+{
+	struct rpcrdma_mw *mw = seg->rl_mw;
+	struct rpcrdma_frmr *f = &mw->r.frmr;
+	struct ib_send_wr *invalidate_wr;
+
+	f->fr_waiter = false;
+	f->fr_state = FRMR_IS_INVALID;
+	invalidate_wr = &f->fr_invwr;
+
+	memset(invalidate_wr, 0, sizeof(*invalidate_wr));
+	invalidate_wr->wr_id = (unsigned long)(void *)mw;
+	invalidate_wr->opcode = IB_WR_LOCAL_INV;
+	invalidate_wr->ex.invalidate_rkey = f->fr_mr->rkey;
+
+	return invalidate_wr;
+}
+
+static void
+__frwr_dma_unmap(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg,
+		 int rc)
+{
+	struct ib_device *device = r_xprt->rx_ia.ri_device;
+	struct rpcrdma_mw *mw = seg->rl_mw;
+	struct rpcrdma_frmr *f = &mw->r.frmr;
+
+	seg->rl_mw = NULL;
+
+	ib_dma_unmap_sg(device, f->sg, f->sg_nents, seg->mr_dir);
+
+	if (!rc)
+		rpcrdma_put_mw(r_xprt, mw);
+	else
+		__frwr_queue_recovery(mw);
+}
+
+/* Invalidate all memory regions that were registered for "req".
+ *
+ * Sleeps until it is safe for the host CPU to access the
+ * previously mapped memory regions.
+ */
+static void
+frwr_op_unmap_sync(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req)
+{
+	struct ib_send_wr *invalidate_wrs, *pos, *prev, *bad_wr;
+	struct rpcrdma_ia *ia = &r_xprt->rx_ia;
+	struct rpcrdma_mr_seg *seg;
+	unsigned int i, nchunks;
+	struct rpcrdma_frmr *f;
+	int rc;
+
+	dprintk("RPC:       %s: req %p\n", __func__, req);
+
+	/* ORDER: Invalidate all of the req's MRs first
+	 *
+	 * Chain the LOCAL_INV Work Requests and post them with
+	 * a single ib_post_send() call.
+	 */
+	invalidate_wrs = pos = prev = NULL;
+	seg = NULL;
+	for (i = 0, nchunks = req->rl_nchunks; nchunks; nchunks--) {
+		seg = &req->rl_segments[i];
+
+		pos = __frwr_prepare_linv_wr(seg);
+
+		if (!invalidate_wrs)
+			invalidate_wrs = pos;
+		else
+			prev->next = pos;
+		prev = pos;
+
+		i += seg->mr_nsegs;
+	}
+	f = &seg->rl_mw->r.frmr;
+
+	/* Strong send queue ordering guarantees that when the
+	 * last WR in the chain completes, all WRs in the chain
+	 * are complete.
+	 */
+	f->fr_invwr.send_flags = IB_SEND_SIGNALED;
+	f->fr_waiter = true;
+	init_completion(&f->fr_linv_done);
+	INIT_CQCOUNT(&r_xprt->rx_ep);
+
+	/* Transport disconnect drains the receive CQ before it
+	 * replaces the QP. The RPC reply handler won't call us
+	 * unless ri_id->qp is a valid pointer.
+	 */
+	rc = ib_post_send(ia->ri_id->qp, invalidate_wrs, &bad_wr);
+	if (rc)
+		pr_warn("%s: ib_post_send failed %i\n", __func__, rc);
+
+	wait_for_completion(&f->fr_linv_done);
+
+	/* ORDER: Now DMA unmap all of the req's MRs, and return
+	 * them to the free MW list.
+	 */
+	for (i = 0, nchunks = req->rl_nchunks; nchunks; nchunks--) {
+		seg = &req->rl_segments[i];
+
+		__frwr_dma_unmap(r_xprt, seg, rc);
+
+		i += seg->mr_nsegs;
+		seg->mr_nsegs = 0;
+	}
+
+	req->rl_nchunks = 0;
+}
+
 /* Post a LOCAL_INV Work Request to prevent further remote access
  * via RDMA READ or RDMA WRITE.
  */
@@ -423,23 +550,24 @@ frwr_op_unmap(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg)
 	struct rpcrdma_ia *ia = &r_xprt->rx_ia;
 	struct rpcrdma_mw *mw = seg1->rl_mw;
 	struct rpcrdma_frmr *frmr = &mw->r.frmr;
-	struct ib_send_wr invalidate_wr, *bad_wr;
+	struct ib_send_wr *invalidate_wr, *bad_wr;
 	int rc, nsegs = seg->mr_nsegs;
 
 	dprintk("RPC:       %s: FRMR %p\n", __func__, mw);
 
 	seg1->rl_mw = NULL;
 	frmr->fr_state = FRMR_IS_INVALID;
+	invalidate_wr = &mw->r.frmr.fr_invwr;
 
-	memset(&invalidate_wr, 0, sizeof(invalidate_wr));
-	invalidate_wr.wr_id = (unsigned long)(void *)mw;
-	invalidate_wr.opcode = IB_WR_LOCAL_INV;
-	invalidate_wr.ex.invalidate_rkey = frmr->fr_mr->rkey;
+	memset(invalidate_wr, 0, sizeof(*invalidate_wr));
+	invalidate_wr->wr_id = (uintptr_t)mw;
+	invalidate_wr->opcode = IB_WR_LOCAL_INV;
+	invalidate_wr->ex.invalidate_rkey = frmr->fr_mr->rkey;
 	DECR_CQCOUNT(&r_xprt->rx_ep);
 
 	ib_dma_unmap_sg(ia->ri_device, frmr->sg, frmr->sg_nents, seg1->mr_dir);
 	read_lock(&ia->ri_qplock);
-	rc = ib_post_send(ia->ri_id->qp, &invalidate_wr, &bad_wr);
+	rc = ib_post_send(ia->ri_id->qp, invalidate_wr, &bad_wr);
 	read_unlock(&ia->ri_qplock);
 	if (rc)
 		goto out_err;
@@ -471,6 +599,7 @@ frwr_op_destroy(struct rpcrdma_buffer *buf)
 
 const struct rpcrdma_memreg_ops rpcrdma_frwr_memreg_ops = {
 	.ro_map				= frwr_op_map,
+	.ro_unmap_sync			= frwr_op_unmap_sync,
 	.ro_unmap			= frwr_op_unmap,
 	.ro_open			= frwr_op_open,
 	.ro_maxpages			= frwr_op_maxpages,
diff --git a/net/sunrpc/xprtrdma/physical_ops.c b/net/sunrpc/xprtrdma/physical_ops.c
index 617b76f22..dbb302ecf 100644
--- a/net/sunrpc/xprtrdma/physical_ops.c
+++ b/net/sunrpc/xprtrdma/physical_ops.c
@@ -83,6 +83,18 @@ physical_op_unmap(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg)
 	return 1;
 }
 
+/* DMA unmap all memory regions that were mapped for "req".
+ */
+static void
+physical_op_unmap_sync(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req)
+{
+	struct ib_device *device = r_xprt->rx_ia.ri_device;
+	unsigned int i;
+
+	for (i = 0; req->rl_nchunks; --req->rl_nchunks)
+		rpcrdma_unmap_one(device, &req->rl_segments[i++]);
+}
+
 static void
 physical_op_destroy(struct rpcrdma_buffer *buf)
 {
@@ -90,6 +102,7 @@ physical_op_destroy(struct rpcrdma_buffer *buf)
 
 const struct rpcrdma_memreg_ops rpcrdma_physical_memreg_ops = {
 	.ro_map				= physical_op_map,
+	.ro_unmap_sync			= physical_op_unmap_sync,
 	.ro_unmap			= physical_op_unmap,
 	.ro_open			= physical_op_open,
 	.ro_maxpages			= physical_op_maxpages,
diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c
index c10d96994..0f28f2d74 100644
--- a/net/sunrpc/xprtrdma/rpc_rdma.c
+++ b/net/sunrpc/xprtrdma/rpc_rdma.c
@@ -804,6 +804,11 @@ rpcrdma_reply_handler(struct rpcrdma_rep *rep)
 	if (req->rl_reply)
 		goto out_duplicate;
 
+	/* Sanity checking has passed. We are now committed
+	 * to complete this transaction.
+	 */
+	list_del_init(&rqst->rq_list);
+	spin_unlock_bh(&xprt->transport_lock);
 	dprintk("RPC:       %s: reply 0x%p completes request 0x%p\n"
 		"                   RPC request 0x%p xid 0x%08x\n",
 			__func__, rep, req, rqst,
@@ -888,12 +893,23 @@ badheader:
 		break;
 	}
 
+	/* Invalidate and flush the data payloads before waking the
+	 * waiting application. This guarantees the memory region is
+	 * properly fenced from the server before the application
+	 * accesses the data. It also ensures proper send flow
+	 * control: waking the next RPC waits until this RPC has
+	 * relinquished all its Send Queue entries.
+	 */
+	if (req->rl_nchunks)
+		r_xprt->rx_ia.ri_ops->ro_unmap_sync(r_xprt, req);
+
 	credits = be32_to_cpu(headerp->rm_credit);
 	if (credits == 0)
 		credits = 1;	/* don't deadlock */
 	else if (credits > r_xprt->rx_buf.rb_max_requests)
 		credits = r_xprt->rx_buf.rb_max_requests;
 
+	spin_lock_bh(&xprt->transport_lock);
 	cwnd = xprt->cwnd;
 	xprt->cwnd = credits << RPC_CWNDSHIFT;
 	if (xprt->cwnd > cwnd)
diff --git a/net/sunrpc/xprtrdma/svc_rdma.c b/net/sunrpc/xprtrdma/svc_rdma.c
index 1b7051bdb..c846ca9f1 100644
--- a/net/sunrpc/xprtrdma/svc_rdma.c
+++ b/net/sunrpc/xprtrdma/svc_rdma.c
@@ -55,6 +55,7 @@ unsigned int svcrdma_ord = RPCRDMA_ORD;
 static unsigned int min_ord = 1;
 static unsigned int max_ord = 4096;
 unsigned int svcrdma_max_requests = RPCRDMA_MAX_REQUESTS;
+unsigned int svcrdma_max_bc_requests = RPCRDMA_MAX_BC_REQUESTS;
 static unsigned int min_max_requests = 4;
 static unsigned int max_max_requests = 16384;
 unsigned int svcrdma_max_req_size = RPCRDMA_MAX_REQ_SIZE;
@@ -71,10 +72,6 @@ atomic_t rdma_stat_rq_prod;
 atomic_t rdma_stat_sq_poll;
 atomic_t rdma_stat_sq_prod;
 
-/* Temporary NFS request map and context caches */
-struct kmem_cache *svc_rdma_map_cachep;
-struct kmem_cache *svc_rdma_ctxt_cachep;
-
 struct workqueue_struct *svc_rdma_wq;
 
 /*
@@ -243,17 +240,16 @@ void svc_rdma_cleanup(void)
 	svc_unreg_xprt_class(&svc_rdma_bc_class);
 #endif
 	svc_unreg_xprt_class(&svc_rdma_class);
-	kmem_cache_destroy(svc_rdma_map_cachep);
-	kmem_cache_destroy(svc_rdma_ctxt_cachep);
 }
 
 int svc_rdma_init(void)
 {
 	dprintk("SVCRDMA Module Init, register RPC RDMA transport\n");
 	dprintk("\tsvcrdma_ord      : %d\n", svcrdma_ord);
-	dprintk("\tmax_requests     : %d\n", svcrdma_max_requests);
-	dprintk("\tsq_depth         : %d\n",
+	dprintk("\tmax_requests     : %u\n", svcrdma_max_requests);
+	dprintk("\tsq_depth         : %u\n",
 		svcrdma_max_requests * RPCRDMA_SQ_DEPTH_MULT);
+	dprintk("\tmax_bc_requests  : %u\n", svcrdma_max_bc_requests);
 	dprintk("\tmax_inline       : %d\n", svcrdma_max_req_size);
 
 	svc_rdma_wq = alloc_workqueue("svc_rdma", 0, 0);
@@ -264,39 +260,10 @@ int svc_rdma_init(void)
 		svcrdma_table_header =
 			register_sysctl_table(svcrdma_root_table);
 
-	/* Create the temporary map cache */
-	svc_rdma_map_cachep = kmem_cache_create("svc_rdma_map_cache",
-						sizeof(struct svc_rdma_req_map),
-						0,
-						SLAB_HWCACHE_ALIGN,
-						NULL);
-	if (!svc_rdma_map_cachep) {
-		printk(KERN_INFO "Could not allocate map cache.\n");
-		goto err0;
-	}
-
-	/* Create the temporary context cache */
-	svc_rdma_ctxt_cachep =
-		kmem_cache_create("svc_rdma_ctxt_cache",
-				  sizeof(struct svc_rdma_op_ctxt),
-				  0,
-				  SLAB_HWCACHE_ALIGN,
-				  NULL);
-	if (!svc_rdma_ctxt_cachep) {
-		printk(KERN_INFO "Could not allocate WR ctxt cache.\n");
-		goto err1;
-	}
-
 	/* Register RDMA with the SVC transport switch */
 	svc_reg_xprt_class(&svc_rdma_class);
 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 	svc_reg_xprt_class(&svc_rdma_bc_class);
 #endif
 	return 0;
- err1:
-	kmem_cache_destroy(svc_rdma_map_cachep);
- err0:
-	unregister_sysctl_table(svcrdma_table_header);
-	destroy_workqueue(svc_rdma_wq);
-	return -ENOMEM;
 }
diff --git a/net/sunrpc/xprtrdma/svc_rdma_backchannel.c b/net/sunrpc/xprtrdma/svc_rdma_backchannel.c
new file mode 100644
index 000000000..65a7c232a
--- /dev/null
+++ b/net/sunrpc/xprtrdma/svc_rdma_backchannel.c
@@ -0,0 +1,371 @@
+/*
+ * Copyright (c) 2015 Oracle.  All rights reserved.
+ *
+ * Support for backward direction RPCs on RPC/RDMA (server-side).
+ */
+
+#include <linux/sunrpc/svc_rdma.h>
+#include "xprt_rdma.h"
+
+#define RPCDBG_FACILITY	RPCDBG_SVCXPRT
+
+#undef SVCRDMA_BACKCHANNEL_DEBUG
+
+int svc_rdma_handle_bc_reply(struct rpc_xprt *xprt, struct rpcrdma_msg *rmsgp,
+			     struct xdr_buf *rcvbuf)
+{
+	struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
+	struct kvec *dst, *src = &rcvbuf->head[0];
+	struct rpc_rqst *req;
+	unsigned long cwnd;
+	u32 credits;
+	size_t len;
+	__be32 xid;
+	__be32 *p;
+	int ret;
+
+	p = (__be32 *)src->iov_base;
+	len = src->iov_len;
+	xid = rmsgp->rm_xid;
+
+#ifdef SVCRDMA_BACKCHANNEL_DEBUG
+	pr_info("%s: xid=%08x, length=%zu\n",
+		__func__, be32_to_cpu(xid), len);
+	pr_info("%s: RPC/RDMA: %*ph\n",
+		__func__, (int)RPCRDMA_HDRLEN_MIN, rmsgp);
+	pr_info("%s:      RPC: %*ph\n",
+		__func__, (int)len, p);
+#endif
+
+	ret = -EAGAIN;
+	if (src->iov_len < 24)
+		goto out_shortreply;
+
+	spin_lock_bh(&xprt->transport_lock);
+	req = xprt_lookup_rqst(xprt, xid);
+	if (!req)
+		goto out_notfound;
+
+	dst = &req->rq_private_buf.head[0];
+	memcpy(&req->rq_private_buf, &req->rq_rcv_buf, sizeof(struct xdr_buf));
+	if (dst->iov_len < len)
+		goto out_unlock;
+	memcpy(dst->iov_base, p, len);
+
+	credits = be32_to_cpu(rmsgp->rm_credit);
+	if (credits == 0)
+		credits = 1;	/* don't deadlock */
+	else if (credits > r_xprt->rx_buf.rb_bc_max_requests)
+		credits = r_xprt->rx_buf.rb_bc_max_requests;
+
+	cwnd = xprt->cwnd;
+	xprt->cwnd = credits << RPC_CWNDSHIFT;
+	if (xprt->cwnd > cwnd)
+		xprt_release_rqst_cong(req->rq_task);
+
+	ret = 0;
+	xprt_complete_rqst(req->rq_task, rcvbuf->len);
+	rcvbuf->len = 0;
+
+out_unlock:
+	spin_unlock_bh(&xprt->transport_lock);
+out:
+	return ret;
+
+out_shortreply:
+	dprintk("svcrdma: short bc reply: xprt=%p, len=%zu\n",
+		xprt, src->iov_len);
+	goto out;
+
+out_notfound:
+	dprintk("svcrdma: unrecognized bc reply: xprt=%p, xid=%08x\n",
+		xprt, be32_to_cpu(xid));
+
+	goto out_unlock;
+}
+
+/* Send a backwards direction RPC call.
+ *
+ * Caller holds the connection's mutex and has already marshaled
+ * the RPC/RDMA request.
+ *
+ * This is similar to svc_rdma_reply, but takes an rpc_rqst
+ * instead, does not support chunks, and avoids blocking memory
+ * allocation.
+ *
+ * XXX: There is still an opportunity to block in svc_rdma_send()
+ * if there are no SQ entries to post the Send. This may occur if
+ * the adapter has a small maximum SQ depth.
+ */
+static int svc_rdma_bc_sendto(struct svcxprt_rdma *rdma,
+			      struct rpc_rqst *rqst)
+{
+	struct xdr_buf *sndbuf = &rqst->rq_snd_buf;
+	struct svc_rdma_op_ctxt *ctxt;
+	struct svc_rdma_req_map *vec;
+	struct ib_send_wr send_wr;
+	int ret;
+
+	vec = svc_rdma_get_req_map(rdma);
+	ret = svc_rdma_map_xdr(rdma, sndbuf, vec);
+	if (ret)
+		goto out_err;
+
+	/* Post a recv buffer to handle the reply for this request. */
+	ret = svc_rdma_post_recv(rdma, GFP_NOIO);
+	if (ret) {
+		pr_err("svcrdma: Failed to post bc receive buffer, err=%d.\n",
+		       ret);
+		pr_err("svcrdma: closing transport %p.\n", rdma);
+		set_bit(XPT_CLOSE, &rdma->sc_xprt.xpt_flags);
+		ret = -ENOTCONN;
+		goto out_err;
+	}
+
+	ctxt = svc_rdma_get_context(rdma);
+	ctxt->pages[0] = virt_to_page(rqst->rq_buffer);
+	ctxt->count = 1;
+
+	ctxt->wr_op = IB_WR_SEND;
+	ctxt->direction = DMA_TO_DEVICE;
+	ctxt->sge[0].lkey = rdma->sc_pd->local_dma_lkey;
+	ctxt->sge[0].length = sndbuf->len;
+	ctxt->sge[0].addr =
+	    ib_dma_map_page(rdma->sc_cm_id->device, ctxt->pages[0], 0,
+			    sndbuf->len, DMA_TO_DEVICE);
+	if (ib_dma_mapping_error(rdma->sc_cm_id->device, ctxt->sge[0].addr)) {
+		ret = -EIO;
+		goto out_unmap;
+	}
+	atomic_inc(&rdma->sc_dma_used);
+
+	memset(&send_wr, 0, sizeof(send_wr));
+	send_wr.wr_id = (unsigned long)ctxt;
+	send_wr.sg_list = ctxt->sge;
+	send_wr.num_sge = 1;
+	send_wr.opcode = IB_WR_SEND;
+	send_wr.send_flags = IB_SEND_SIGNALED;
+
+	ret = svc_rdma_send(rdma, &send_wr);
+	if (ret) {
+		ret = -EIO;
+		goto out_unmap;
+	}
+
+out_err:
+	svc_rdma_put_req_map(rdma, vec);
+	dprintk("svcrdma: %s returns %d\n", __func__, ret);
+	return ret;
+
+out_unmap:
+	svc_rdma_unmap_dma(ctxt);
+	svc_rdma_put_context(ctxt, 1);
+	goto out_err;
+}
+
+/* Server-side transport endpoint wants a whole page for its send
+ * buffer. The client RPC code constructs the RPC header in this
+ * buffer before it invokes ->send_request.
+ *
+ * Returns NULL if there was a temporary allocation failure.
+ */
+static void *
+xprt_rdma_bc_allocate(struct rpc_task *task, size_t size)
+{
+	struct rpc_rqst *rqst = task->tk_rqstp;
+	struct svc_xprt *sxprt = rqst->rq_xprt->bc_xprt;
+	struct svcxprt_rdma *rdma;
+	struct page *page;
+
+	rdma = container_of(sxprt, struct svcxprt_rdma, sc_xprt);
+
+	/* Prevent an infinite loop: try to make this case work */
+	if (size > PAGE_SIZE)
+		WARN_ONCE(1, "svcrdma: large bc buffer request (size %zu)\n",
+			  size);
+
+	page = alloc_page(RPCRDMA_DEF_GFP);
+	if (!page)
+		return NULL;
+
+	return page_address(page);
+}
+
+static void
+xprt_rdma_bc_free(void *buffer)
+{
+	/* No-op: ctxt and page have already been freed. */
+}
+
+static int
+rpcrdma_bc_send_request(struct svcxprt_rdma *rdma, struct rpc_rqst *rqst)
+{
+	struct rpc_xprt *xprt = rqst->rq_xprt;
+	struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
+	struct rpcrdma_msg *headerp = (struct rpcrdma_msg *)rqst->rq_buffer;
+	int rc;
+
+	/* Space in the send buffer for an RPC/RDMA header is reserved
+	 * via xprt->tsh_size.
+	 */
+	headerp->rm_xid = rqst->rq_xid;
+	headerp->rm_vers = rpcrdma_version;
+	headerp->rm_credit = cpu_to_be32(r_xprt->rx_buf.rb_bc_max_requests);
+	headerp->rm_type = rdma_msg;
+	headerp->rm_body.rm_chunks[0] = xdr_zero;
+	headerp->rm_body.rm_chunks[1] = xdr_zero;
+	headerp->rm_body.rm_chunks[2] = xdr_zero;
+
+#ifdef SVCRDMA_BACKCHANNEL_DEBUG
+	pr_info("%s: %*ph\n", __func__, 64, rqst->rq_buffer);
+#endif
+
+	rc = svc_rdma_bc_sendto(rdma, rqst);
+	if (rc)
+		goto drop_connection;
+	return rc;
+
+drop_connection:
+	dprintk("svcrdma: failed to send bc call\n");
+	xprt_disconnect_done(xprt);
+	return -ENOTCONN;
+}
+
+/* Send an RPC call on the passive end of a transport
+ * connection.
+ */
+static int
+xprt_rdma_bc_send_request(struct rpc_task *task)
+{
+	struct rpc_rqst *rqst = task->tk_rqstp;
+	struct svc_xprt *sxprt = rqst->rq_xprt->bc_xprt;
+	struct svcxprt_rdma *rdma;
+	int ret;
+
+	dprintk("svcrdma: sending bc call with xid: %08x\n",
+		be32_to_cpu(rqst->rq_xid));
+
+	if (!mutex_trylock(&sxprt->xpt_mutex)) {
+		rpc_sleep_on(&sxprt->xpt_bc_pending, task, NULL);
+		if (!mutex_trylock(&sxprt->xpt_mutex))
+			return -EAGAIN;
+		rpc_wake_up_queued_task(&sxprt->xpt_bc_pending, task);
+	}
+
+	ret = -ENOTCONN;
+	rdma = container_of(sxprt, struct svcxprt_rdma, sc_xprt);
+	if (!test_bit(XPT_DEAD, &sxprt->xpt_flags))
+		ret = rpcrdma_bc_send_request(rdma, rqst);
+
+	mutex_unlock(&sxprt->xpt_mutex);
+
+	if (ret < 0)
+		return ret;
+	return 0;
+}
+
+static void
+xprt_rdma_bc_close(struct rpc_xprt *xprt)
+{
+	dprintk("svcrdma: %s: xprt %p\n", __func__, xprt);
+}
+
+static void
+xprt_rdma_bc_put(struct rpc_xprt *xprt)
+{
+	dprintk("svcrdma: %s: xprt %p\n", __func__, xprt);
+
+	xprt_free(xprt);
+	module_put(THIS_MODULE);
+}
+
+static struct rpc_xprt_ops xprt_rdma_bc_procs = {
+	.reserve_xprt		= xprt_reserve_xprt_cong,
+	.release_xprt		= xprt_release_xprt_cong,
+	.alloc_slot		= xprt_alloc_slot,
+	.release_request	= xprt_release_rqst_cong,
+	.buf_alloc		= xprt_rdma_bc_allocate,
+	.buf_free		= xprt_rdma_bc_free,
+	.send_request		= xprt_rdma_bc_send_request,
+	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
+	.close			= xprt_rdma_bc_close,
+	.destroy		= xprt_rdma_bc_put,
+	.print_stats		= xprt_rdma_print_stats
+};
+
+static const struct rpc_timeout xprt_rdma_bc_timeout = {
+	.to_initval = 60 * HZ,
+	.to_maxval = 60 * HZ,
+};
+
+/* It shouldn't matter if the number of backchannel session slots
+ * doesn't match the number of RPC/RDMA credits. That just means
+ * one or the other will have extra slots that aren't used.
+ */
+static struct rpc_xprt *
+xprt_setup_rdma_bc(struct xprt_create *args)
+{
+	struct rpc_xprt *xprt;
+	struct rpcrdma_xprt *new_xprt;
+
+	if (args->addrlen > sizeof(xprt->addr)) {
+		dprintk("RPC:       %s: address too large\n", __func__);
+		return ERR_PTR(-EBADF);
+	}
+
+	xprt = xprt_alloc(args->net, sizeof(*new_xprt),
+			  RPCRDMA_MAX_BC_REQUESTS,
+			  RPCRDMA_MAX_BC_REQUESTS);
+	if (!xprt) {
+		dprintk("RPC:       %s: couldn't allocate rpc_xprt\n",
+			__func__);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	xprt->timeout = &xprt_rdma_bc_timeout;
+	xprt_set_bound(xprt);
+	xprt_set_connected(xprt);
+	xprt->bind_timeout = RPCRDMA_BIND_TO;
+	xprt->reestablish_timeout = RPCRDMA_INIT_REEST_TO;
+	xprt->idle_timeout = RPCRDMA_IDLE_DISC_TO;
+
+	xprt->prot = XPRT_TRANSPORT_BC_RDMA;
+	xprt->tsh_size = RPCRDMA_HDRLEN_MIN / sizeof(__be32);
+	xprt->ops = &xprt_rdma_bc_procs;
+
+	memcpy(&xprt->addr, args->dstaddr, args->addrlen);
+	xprt->addrlen = args->addrlen;
+	xprt_rdma_format_addresses(xprt, (struct sockaddr *)&xprt->addr);
+	xprt->resvport = 0;
+
+	xprt->max_payload = xprt_rdma_max_inline_read;
+
+	new_xprt = rpcx_to_rdmax(xprt);
+	new_xprt->rx_buf.rb_bc_max_requests = xprt->max_reqs;
+
+	xprt_get(xprt);
+	args->bc_xprt->xpt_bc_xprt = xprt;
+	xprt->bc_xprt = args->bc_xprt;
+
+	if (!try_module_get(THIS_MODULE))
+		goto out_fail;
+
+	/* Final put for backchannel xprt is in __svc_rdma_free */
+	xprt_get(xprt);
+	return xprt;
+
+out_fail:
+	xprt_rdma_free_addresses(xprt);
+	args->bc_xprt->xpt_bc_xprt = NULL;
+	xprt_put(xprt);
+	xprt_free(xprt);
+	return ERR_PTR(-EINVAL);
+}
+
+struct xprt_class xprt_rdma_bc = {
+	.list			= LIST_HEAD_INIT(xprt_rdma_bc.list),
+	.name			= "rdma backchannel",
+	.owner			= THIS_MODULE,
+	.ident			= XPRT_TRANSPORT_BC_RDMA,
+	.setup			= xprt_setup_rdma_bc,
+};
diff --git a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
index ff4f01e52..c8b8a8b41 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
@@ -144,6 +144,7 @@ int rdma_read_chunk_lcl(struct svcxprt_rdma *xprt,
 
 		head->arg.pages[pg_no] = rqstp->rq_arg.pages[pg_no];
 		head->arg.page_len += len;
+
 		head->arg.len += len;
 		if (!pg_off)
 			head->count++;
@@ -160,8 +161,7 @@ int rdma_read_chunk_lcl(struct svcxprt_rdma *xprt,
 			goto err;
 		atomic_inc(&xprt->sc_dma_used);
 
-		/* The lkey here is either a local dma lkey or a dma_mr lkey */
-		ctxt->sge[pno].lkey = xprt->sc_dma_lkey;
+		ctxt->sge[pno].lkey = xprt->sc_pd->local_dma_lkey;
 		ctxt->sge[pno].length = len;
 		ctxt->count++;
 
@@ -567,6 +567,38 @@ static int rdma_read_complete(struct svc_rqst *rqstp,
 	return ret;
 }
 
+/* By convention, backchannel calls arrive via rdma_msg type
+ * messages, and never populate the chunk lists. This makes
+ * the RPC/RDMA header small and fixed in size, so it is
+ * straightforward to check the RPC header's direction field.
+ */
+static bool
+svc_rdma_is_backchannel_reply(struct svc_xprt *xprt, struct rpcrdma_msg *rmsgp)
+{
+	__be32 *p = (__be32 *)rmsgp;
+
+	if (!xprt->xpt_bc_xprt)
+		return false;
+
+	if (rmsgp->rm_type != rdma_msg)
+		return false;
+	if (rmsgp->rm_body.rm_chunks[0] != xdr_zero)
+		return false;
+	if (rmsgp->rm_body.rm_chunks[1] != xdr_zero)
+		return false;
+	if (rmsgp->rm_body.rm_chunks[2] != xdr_zero)
+		return false;
+
+	/* sanity */
+	if (p[7] != rmsgp->rm_xid)
+		return false;
+	/* call direction */
+	if (p[8] == cpu_to_be32(RPC_CALL))
+		return false;
+
+	return true;
+}
+
 /*
  * Set up the rqstp thread context to point to the RQ buffer. If
  * necessary, pull additional data from the client with an RDMA_READ
@@ -632,6 +664,15 @@ int svc_rdma_recvfrom(struct svc_rqst *rqstp)
 		goto close_out;
 	}
 
+	if (svc_rdma_is_backchannel_reply(xprt, rmsgp)) {
+		ret = svc_rdma_handle_bc_reply(xprt->xpt_bc_xprt, rmsgp,
+					       &rqstp->rq_arg);
+		svc_rdma_put_context(ctxt, 0);
+		if (ret)
+			goto repost;
+		return ret;
+	}
+
 	/* Read read-list data. */
 	ret = rdma_read_chunks(rdma_xprt, rmsgp, rqstp, ctxt);
 	if (ret > 0) {
@@ -668,4 +709,15 @@ int svc_rdma_recvfrom(struct svc_rqst *rqstp)
 	set_bit(XPT_CLOSE, &xprt->xpt_flags);
 defer:
 	return 0;
+
+repost:
+	ret = svc_rdma_post_recv(rdma_xprt, GFP_KERNEL);
+	if (ret) {
+		pr_err("svcrdma: could not post a receive buffer, err=%d.\n",
+		       ret);
+		pr_err("svcrdma: closing transport %p.\n", rdma_xprt);
+		set_bit(XPT_CLOSE, &rdma_xprt->sc_xprt.xpt_flags);
+		ret = -ENOTCONN;
+	}
+	return ret;
 }
diff --git a/net/sunrpc/xprtrdma/svc_rdma_sendto.c b/net/sunrpc/xprtrdma/svc_rdma_sendto.c
index 969a1ab75..df57f3ce6 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_sendto.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_sendto.c
@@ -50,9 +50,9 @@
 
 #define RPCDBG_FACILITY	RPCDBG_SVCXPRT
 
-static int map_xdr(struct svcxprt_rdma *xprt,
-		   struct xdr_buf *xdr,
-		   struct svc_rdma_req_map *vec)
+int svc_rdma_map_xdr(struct svcxprt_rdma *xprt,
+		     struct xdr_buf *xdr,
+		     struct svc_rdma_req_map *vec)
 {
 	int sge_no;
 	u32 sge_bytes;
@@ -62,7 +62,7 @@ static int map_xdr(struct svcxprt_rdma *xprt,
 
 	if (xdr->len !=
 	    (xdr->head[0].iov_len + xdr->page_len + xdr->tail[0].iov_len)) {
-		pr_err("svcrdma: map_xdr: XDR buffer length error\n");
+		pr_err("svcrdma: %s: XDR buffer length error\n", __func__);
 		return -EIO;
 	}
 
@@ -97,9 +97,9 @@ static int map_xdr(struct svcxprt_rdma *xprt,
 		sge_no++;
 	}
 
-	dprintk("svcrdma: map_xdr: sge_no %d page_no %d "
+	dprintk("svcrdma: %s: sge_no %d page_no %d "
 		"page_base %u page_len %u head_len %zu tail_len %zu\n",
-		sge_no, page_no, xdr->page_base, xdr->page_len,
+		__func__, sge_no, page_no, xdr->page_base, xdr->page_len,
 		xdr->head[0].iov_len, xdr->tail[0].iov_len);
 
 	vec->count = sge_no;
@@ -265,7 +265,7 @@ static int send_write(struct svcxprt_rdma *xprt, struct svc_rqst *rqstp,
 					 sge[sge_no].addr))
 			goto err;
 		atomic_inc(&xprt->sc_dma_used);
-		sge[sge_no].lkey = xprt->sc_dma_lkey;
+		sge[sge_no].lkey = xprt->sc_pd->local_dma_lkey;
 		ctxt->count++;
 		sge_off = 0;
 		sge_no++;
@@ -465,7 +465,7 @@ static int send_reply(struct svcxprt_rdma *rdma,
 	int ret;
 
 	/* Post a recv buffer to handle another request. */
-	ret = svc_rdma_post_recv(rdma);
+	ret = svc_rdma_post_recv(rdma, GFP_KERNEL);
 	if (ret) {
 		printk(KERN_INFO
 		       "svcrdma: could not post a receive buffer, err=%d."
@@ -480,7 +480,7 @@ static int send_reply(struct svcxprt_rdma *rdma,
 	ctxt->count = 1;
 
 	/* Prepare the SGE for the RPCRDMA Header */
-	ctxt->sge[0].lkey = rdma->sc_dma_lkey;
+	ctxt->sge[0].lkey = rdma->sc_pd->local_dma_lkey;
 	ctxt->sge[0].length = svc_rdma_xdr_get_reply_hdr_len(rdma_resp);
 	ctxt->sge[0].addr =
 	    ib_dma_map_page(rdma->sc_cm_id->device, page, 0,
@@ -504,7 +504,7 @@ static int send_reply(struct svcxprt_rdma *rdma,
 					 ctxt->sge[sge_no].addr))
 			goto err;
 		atomic_inc(&rdma->sc_dma_used);
-		ctxt->sge[sge_no].lkey = rdma->sc_dma_lkey;
+		ctxt->sge[sge_no].lkey = rdma->sc_pd->local_dma_lkey;
 		ctxt->sge[sge_no].length = sge_bytes;
 	}
 	if (byte_count != 0) {
@@ -591,14 +591,17 @@ int svc_rdma_sendto(struct svc_rqst *rqstp)
 	/* Build an req vec for the XDR */
 	ctxt = svc_rdma_get_context(rdma);
 	ctxt->direction = DMA_TO_DEVICE;
-	vec = svc_rdma_get_req_map();
-	ret = map_xdr(rdma, &rqstp->rq_res, vec);
+	vec = svc_rdma_get_req_map(rdma);
+	ret = svc_rdma_map_xdr(rdma, &rqstp->rq_res, vec);
 	if (ret)
 		goto err0;
 	inline_bytes = rqstp->rq_res.len;
 
 	/* Create the RDMA response header */
-	res_page = alloc_page(GFP_KERNEL | __GFP_NOFAIL);
+	ret = -ENOMEM;
+	res_page = alloc_page(GFP_KERNEL);
+	if (!res_page)
+		goto err0;
 	rdma_resp = page_address(res_page);
 	reply_ary = svc_rdma_get_reply_array(rdma_argp);
 	if (reply_ary)
@@ -630,14 +633,14 @@ int svc_rdma_sendto(struct svc_rqst *rqstp)
 
 	ret = send_reply(rdma, rqstp, res_page, rdma_resp, ctxt, vec,
 			 inline_bytes);
-	svc_rdma_put_req_map(vec);
+	svc_rdma_put_req_map(rdma, vec);
 	dprintk("svcrdma: send_reply returns %d\n", ret);
 	return ret;
 
  err1:
 	put_page(res_page);
  err0:
-	svc_rdma_put_req_map(vec);
+	svc_rdma_put_req_map(rdma, vec);
 	svc_rdma_put_context(ctxt, 0);
 	return ret;
 }
diff --git a/net/sunrpc/xprtrdma/svc_rdma_transport.c b/net/sunrpc/xprtrdma/svc_rdma_transport.c
index b348b4ade..5763825d0 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_transport.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_transport.c
@@ -153,18 +153,76 @@ static void svc_rdma_bc_free(struct svc_xprt *xprt)
 }
 #endif	/* CONFIG_SUNRPC_BACKCHANNEL */
 
-struct svc_rdma_op_ctxt *svc_rdma_get_context(struct svcxprt_rdma *xprt)
+static struct svc_rdma_op_ctxt *alloc_ctxt(struct svcxprt_rdma *xprt,
+					   gfp_t flags)
 {
 	struct svc_rdma_op_ctxt *ctxt;
 
-	ctxt = kmem_cache_alloc(svc_rdma_ctxt_cachep,
-				GFP_KERNEL | __GFP_NOFAIL);
-	ctxt->xprt = xprt;
-	INIT_LIST_HEAD(&ctxt->dto_q);
+	ctxt = kmalloc(sizeof(*ctxt), flags);
+	if (ctxt) {
+		ctxt->xprt = xprt;
+		INIT_LIST_HEAD(&ctxt->free);
+		INIT_LIST_HEAD(&ctxt->dto_q);
+	}
+	return ctxt;
+}
+
+static bool svc_rdma_prealloc_ctxts(struct svcxprt_rdma *xprt)
+{
+	unsigned int i;
+
+	/* Each RPC/RDMA credit can consume a number of send
+	 * and receive WQEs. One ctxt is allocated for each.
+	 */
+	i = xprt->sc_sq_depth + xprt->sc_rq_depth;
+
+	while (i--) {
+		struct svc_rdma_op_ctxt *ctxt;
+
+		ctxt = alloc_ctxt(xprt, GFP_KERNEL);
+		if (!ctxt) {
+			dprintk("svcrdma: No memory for RDMA ctxt\n");
+			return false;
+		}
+		list_add(&ctxt->free, &xprt->sc_ctxts);
+	}
+	return true;
+}
+
+struct svc_rdma_op_ctxt *svc_rdma_get_context(struct svcxprt_rdma *xprt)
+{
+	struct svc_rdma_op_ctxt *ctxt = NULL;
+
+	spin_lock_bh(&xprt->sc_ctxt_lock);
+	xprt->sc_ctxt_used++;
+	if (list_empty(&xprt->sc_ctxts))
+		goto out_empty;
+
+	ctxt = list_first_entry(&xprt->sc_ctxts,
+				struct svc_rdma_op_ctxt, free);
+	list_del_init(&ctxt->free);
+	spin_unlock_bh(&xprt->sc_ctxt_lock);
+
+out:
 	ctxt->count = 0;
 	ctxt->frmr = NULL;
-	atomic_inc(&xprt->sc_ctxt_used);
 	return ctxt;
+
+out_empty:
+	/* Either pre-allocation missed the mark, or send
+	 * queue accounting is broken.
+	 */
+	spin_unlock_bh(&xprt->sc_ctxt_lock);
+
+	ctxt = alloc_ctxt(xprt, GFP_NOIO);
+	if (ctxt)
+		goto out;
+
+	spin_lock_bh(&xprt->sc_ctxt_lock);
+	xprt->sc_ctxt_used--;
+	spin_unlock_bh(&xprt->sc_ctxt_lock);
+	WARN_ONCE(1, "svcrdma: empty RDMA ctxt list?\n");
+	return NULL;
 }
 
 void svc_rdma_unmap_dma(struct svc_rdma_op_ctxt *ctxt)
@@ -174,11 +232,11 @@ void svc_rdma_unmap_dma(struct svc_rdma_op_ctxt *ctxt)
 	for (i = 0; i < ctxt->count && ctxt->sge[i].length; i++) {
 		/*
 		 * Unmap the DMA addr in the SGE if the lkey matches
-		 * the sc_dma_lkey, otherwise, ignore it since it is
+		 * the local_dma_lkey, otherwise, ignore it since it is
 		 * an FRMR lkey and will be unmapped later when the
 		 * last WR that uses it completes.
 		 */
-		if (ctxt->sge[i].lkey == xprt->sc_dma_lkey) {
+		if (ctxt->sge[i].lkey == xprt->sc_pd->local_dma_lkey) {
 			atomic_dec(&xprt->sc_dma_used);
 			ib_dma_unmap_page(xprt->sc_cm_id->device,
 					    ctxt->sge[i].addr,
@@ -190,35 +248,108 @@ void svc_rdma_unmap_dma(struct svc_rdma_op_ctxt *ctxt)
 
 void svc_rdma_put_context(struct svc_rdma_op_ctxt *ctxt, int free_pages)
 {
-	struct svcxprt_rdma *xprt;
+	struct svcxprt_rdma *xprt = ctxt->xprt;
 	int i;
 
-	xprt = ctxt->xprt;
 	if (free_pages)
 		for (i = 0; i < ctxt->count; i++)
 			put_page(ctxt->pages[i]);
 
-	kmem_cache_free(svc_rdma_ctxt_cachep, ctxt);
-	atomic_dec(&xprt->sc_ctxt_used);
+	spin_lock_bh(&xprt->sc_ctxt_lock);
+	xprt->sc_ctxt_used--;
+	list_add(&ctxt->free, &xprt->sc_ctxts);
+	spin_unlock_bh(&xprt->sc_ctxt_lock);
 }
 
-/*
- * Temporary NFS req mappings are shared across all transport
- * instances. These are short lived and should be bounded by the number
- * of concurrent server threads * depth of the SQ.
- */
-struct svc_rdma_req_map *svc_rdma_get_req_map(void)
+static void svc_rdma_destroy_ctxts(struct svcxprt_rdma *xprt)
+{
+	while (!list_empty(&xprt->sc_ctxts)) {
+		struct svc_rdma_op_ctxt *ctxt;
+
+		ctxt = list_first_entry(&xprt->sc_ctxts,
+					struct svc_rdma_op_ctxt, free);
+		list_del(&ctxt->free);
+		kfree(ctxt);
+	}
+}
+
+static struct svc_rdma_req_map *alloc_req_map(gfp_t flags)
 {
 	struct svc_rdma_req_map *map;
-	map = kmem_cache_alloc(svc_rdma_map_cachep,
-			       GFP_KERNEL | __GFP_NOFAIL);
+
+	map = kmalloc(sizeof(*map), flags);
+	if (map)
+		INIT_LIST_HEAD(&map->free);
+	return map;
+}
+
+static bool svc_rdma_prealloc_maps(struct svcxprt_rdma *xprt)
+{
+	unsigned int i;
+
+	/* One for each receive buffer on this connection. */
+	i = xprt->sc_max_requests;
+
+	while (i--) {
+		struct svc_rdma_req_map *map;
+
+		map = alloc_req_map(GFP_KERNEL);
+		if (!map) {
+			dprintk("svcrdma: No memory for request map\n");
+			return false;
+		}
+		list_add(&map->free, &xprt->sc_maps);
+	}
+	return true;
+}
+
+struct svc_rdma_req_map *svc_rdma_get_req_map(struct svcxprt_rdma *xprt)
+{
+	struct svc_rdma_req_map *map = NULL;
+
+	spin_lock(&xprt->sc_map_lock);
+	if (list_empty(&xprt->sc_maps))
+		goto out_empty;
+
+	map = list_first_entry(&xprt->sc_maps,
+			       struct svc_rdma_req_map, free);
+	list_del_init(&map->free);
+	spin_unlock(&xprt->sc_map_lock);
+
+out:
 	map->count = 0;
 	return map;
+
+out_empty:
+	spin_unlock(&xprt->sc_map_lock);
+
+	/* Pre-allocation amount was incorrect */
+	map = alloc_req_map(GFP_NOIO);
+	if (map)
+		goto out;
+
+	WARN_ONCE(1, "svcrdma: empty request map list?\n");
+	return NULL;
+}
+
+void svc_rdma_put_req_map(struct svcxprt_rdma *xprt,
+			  struct svc_rdma_req_map *map)
+{
+	spin_lock(&xprt->sc_map_lock);
+	list_add(&map->free, &xprt->sc_maps);
+	spin_unlock(&xprt->sc_map_lock);
 }
 
-void svc_rdma_put_req_map(struct svc_rdma_req_map *map)
+static void svc_rdma_destroy_maps(struct svcxprt_rdma *xprt)
 {
-	kmem_cache_free(svc_rdma_map_cachep, map);
+	while (!list_empty(&xprt->sc_maps)) {
+		struct svc_rdma_req_map *map;
+
+		map = list_first_entry(&xprt->sc_maps,
+				       struct svc_rdma_req_map, free);
+		list_del(&map->free);
+		kfree(map);
+	}
 }
 
 /* ib_cq event handler */
@@ -386,46 +517,44 @@ static void rq_cq_reap(struct svcxprt_rdma *xprt)
 static void process_context(struct svcxprt_rdma *xprt,
 			    struct svc_rdma_op_ctxt *ctxt)
 {
+	struct svc_rdma_op_ctxt *read_hdr;
+	int free_pages = 0;
+
 	svc_rdma_unmap_dma(ctxt);
 
 	switch (ctxt->wr_op) {
 	case IB_WR_SEND:
-		if (ctxt->frmr)
-			pr_err("svcrdma: SEND: ctxt->frmr != NULL\n");
-		svc_rdma_put_context(ctxt, 1);
+		free_pages = 1;
 		break;
 
 	case IB_WR_RDMA_WRITE:
-		if (ctxt->frmr)
-			pr_err("svcrdma: WRITE: ctxt->frmr != NULL\n");
-		svc_rdma_put_context(ctxt, 0);
 		break;
 
 	case IB_WR_RDMA_READ:
 	case IB_WR_RDMA_READ_WITH_INV:
 		svc_rdma_put_frmr(xprt, ctxt->frmr);
-		if (test_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags)) {
-			struct svc_rdma_op_ctxt *read_hdr = ctxt->read_hdr;
-			if (read_hdr) {
-				spin_lock_bh(&xprt->sc_rq_dto_lock);
-				set_bit(XPT_DATA, &xprt->sc_xprt.xpt_flags);
-				list_add_tail(&read_hdr->dto_q,
-					      &xprt->sc_read_complete_q);
-				spin_unlock_bh(&xprt->sc_rq_dto_lock);
-			} else {
-				pr_err("svcrdma: ctxt->read_hdr == NULL\n");
-			}
-			svc_xprt_enqueue(&xprt->sc_xprt);
-		}
+
+		if (!test_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags))
+			break;
+
+		read_hdr = ctxt->read_hdr;
 		svc_rdma_put_context(ctxt, 0);
-		break;
+
+		spin_lock_bh(&xprt->sc_rq_dto_lock);
+		set_bit(XPT_DATA, &xprt->sc_xprt.xpt_flags);
+		list_add_tail(&read_hdr->dto_q,
+			      &xprt->sc_read_complete_q);
+		spin_unlock_bh(&xprt->sc_rq_dto_lock);
+		svc_xprt_enqueue(&xprt->sc_xprt);
+		return;
 
 	default:
-		printk(KERN_ERR "svcrdma: unexpected completion type, "
-		       "opcode=%d\n",
-		       ctxt->wr_op);
+		dprintk("svcrdma: unexpected completion opcode=%d\n",
+			ctxt->wr_op);
 		break;
 	}
+
+	svc_rdma_put_context(ctxt, free_pages);
 }
 
 /*
@@ -523,19 +652,15 @@ static struct svcxprt_rdma *rdma_create_xprt(struct svc_serv *serv,
 	INIT_LIST_HEAD(&cma_xprt->sc_rq_dto_q);
 	INIT_LIST_HEAD(&cma_xprt->sc_read_complete_q);
 	INIT_LIST_HEAD(&cma_xprt->sc_frmr_q);
+	INIT_LIST_HEAD(&cma_xprt->sc_ctxts);
+	INIT_LIST_HEAD(&cma_xprt->sc_maps);
 	init_waitqueue_head(&cma_xprt->sc_send_wait);
 
 	spin_lock_init(&cma_xprt->sc_lock);
 	spin_lock_init(&cma_xprt->sc_rq_dto_lock);
 	spin_lock_init(&cma_xprt->sc_frmr_q_lock);
-
-	cma_xprt->sc_ord = svcrdma_ord;
-
-	cma_xprt->sc_max_req_size = svcrdma_max_req_size;
-	cma_xprt->sc_max_requests = svcrdma_max_requests;
-	cma_xprt->sc_sq_depth = svcrdma_max_requests * RPCRDMA_SQ_DEPTH_MULT;
-	atomic_set(&cma_xprt->sc_sq_count, 0);
-	atomic_set(&cma_xprt->sc_ctxt_used, 0);
+	spin_lock_init(&cma_xprt->sc_ctxt_lock);
+	spin_lock_init(&cma_xprt->sc_map_lock);
 
 	if (listener)
 		set_bit(XPT_LISTENER, &cma_xprt->sc_xprt.xpt_flags);
@@ -543,7 +668,7 @@ static struct svcxprt_rdma *rdma_create_xprt(struct svc_serv *serv,
 	return cma_xprt;
 }
 
-int svc_rdma_post_recv(struct svcxprt_rdma *xprt)
+int svc_rdma_post_recv(struct svcxprt_rdma *xprt, gfp_t flags)
 {
 	struct ib_recv_wr recv_wr, *bad_recv_wr;
 	struct svc_rdma_op_ctxt *ctxt;
@@ -561,7 +686,9 @@ int svc_rdma_post_recv(struct svcxprt_rdma *xprt)
 			pr_err("svcrdma: Too many sges (%d)\n", sge_no);
 			goto err_put_ctxt;
 		}
-		page = alloc_page(GFP_KERNEL | __GFP_NOFAIL);
+		page = alloc_page(flags);
+		if (!page)
+			goto err_put_ctxt;
 		ctxt->pages[sge_no] = page;
 		pa = ib_dma_map_page(xprt->sc_cm_id->device,
 				     page, 0, PAGE_SIZE,
@@ -571,7 +698,7 @@ int svc_rdma_post_recv(struct svcxprt_rdma *xprt)
 		atomic_inc(&xprt->sc_dma_used);
 		ctxt->sge[sge_no].addr = pa;
 		ctxt->sge[sge_no].length = PAGE_SIZE;
-		ctxt->sge[sge_no].lkey = xprt->sc_dma_lkey;
+		ctxt->sge[sge_no].lkey = xprt->sc_pd->local_dma_lkey;
 		ctxt->count = sge_no + 1;
 		buflen += PAGE_SIZE;
 	}
@@ -886,11 +1013,9 @@ static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt)
 	struct rdma_conn_param conn_param;
 	struct ib_cq_init_attr cq_attr = {};
 	struct ib_qp_init_attr qp_attr;
-	struct ib_device_attr devattr;
-	int uninitialized_var(dma_mr_acc);
-	int need_dma_mr = 0;
-	int ret;
-	int i;
+	struct ib_device *dev;
+	unsigned int i;
+	int ret = 0;
 
 	listen_rdma = container_of(xprt, struct svcxprt_rdma, sc_xprt);
 	clear_bit(XPT_CONN, &xprt->xpt_flags);
@@ -910,37 +1035,42 @@ static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt)
 	dprintk("svcrdma: newxprt from accept queue = %p, cm_id=%p\n",
 		newxprt, newxprt->sc_cm_id);
 
-	ret = ib_query_device(newxprt->sc_cm_id->device, &devattr);
-	if (ret) {
-		dprintk("svcrdma: could not query device attributes on "
-			"device %p, rc=%d\n", newxprt->sc_cm_id->device, ret);
-		goto errout;
-	}
+	dev = newxprt->sc_cm_id->device;
 
 	/* Qualify the transport resource defaults with the
 	 * capabilities of this particular device */
-	newxprt->sc_max_sge = min((size_t)devattr.max_sge,
+	newxprt->sc_max_sge = min((size_t)dev->attrs.max_sge,
 				  (size_t)RPCSVC_MAXPAGES);
-	newxprt->sc_max_sge_rd = min_t(size_t, devattr.max_sge_rd,
+	newxprt->sc_max_sge_rd = min_t(size_t, dev->attrs.max_sge_rd,
 				       RPCSVC_MAXPAGES);
-	newxprt->sc_max_requests = min((size_t)devattr.max_qp_wr,
-				   (size_t)svcrdma_max_requests);
-	newxprt->sc_sq_depth = RPCRDMA_SQ_DEPTH_MULT * newxprt->sc_max_requests;
+	newxprt->sc_max_req_size = svcrdma_max_req_size;
+	newxprt->sc_max_requests = min_t(u32, dev->attrs.max_qp_wr,
+					 svcrdma_max_requests);
+	newxprt->sc_max_bc_requests = min_t(u32, dev->attrs.max_qp_wr,
+					    svcrdma_max_bc_requests);
+	newxprt->sc_rq_depth = newxprt->sc_max_requests +
+			       newxprt->sc_max_bc_requests;
+	newxprt->sc_sq_depth = RPCRDMA_SQ_DEPTH_MULT * newxprt->sc_rq_depth;
+
+	if (!svc_rdma_prealloc_ctxts(newxprt))
+		goto errout;
+	if (!svc_rdma_prealloc_maps(newxprt))
+		goto errout;
 
 	/*
 	 * Limit ORD based on client limit, local device limit, and
 	 * configured svcrdma limit.
 	 */
-	newxprt->sc_ord = min_t(size_t, devattr.max_qp_rd_atom, newxprt->sc_ord);
+	newxprt->sc_ord = min_t(size_t, dev->attrs.max_qp_rd_atom, newxprt->sc_ord);
 	newxprt->sc_ord = min_t(size_t,	svcrdma_ord, newxprt->sc_ord);
 
-	newxprt->sc_pd = ib_alloc_pd(newxprt->sc_cm_id->device);
+	newxprt->sc_pd = ib_alloc_pd(dev);
 	if (IS_ERR(newxprt->sc_pd)) {
 		dprintk("svcrdma: error creating PD for connect request\n");
 		goto errout;
 	}
 	cq_attr.cqe = newxprt->sc_sq_depth;
-	newxprt->sc_sq_cq = ib_create_cq(newxprt->sc_cm_id->device,
+	newxprt->sc_sq_cq = ib_create_cq(dev,
 					 sq_comp_handler,
 					 cq_event_handler,
 					 newxprt,
@@ -949,8 +1079,8 @@ static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt)
 		dprintk("svcrdma: error creating SQ CQ for connect request\n");
 		goto errout;
 	}
-	cq_attr.cqe = newxprt->sc_max_requests;
-	newxprt->sc_rq_cq = ib_create_cq(newxprt->sc_cm_id->device,
+	cq_attr.cqe = newxprt->sc_rq_depth;
+	newxprt->sc_rq_cq = ib_create_cq(dev,
 					 rq_comp_handler,
 					 cq_event_handler,
 					 newxprt,
@@ -964,7 +1094,7 @@ static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt)
 	qp_attr.event_handler = qp_event_handler;
 	qp_attr.qp_context = &newxprt->sc_xprt;
 	qp_attr.cap.max_send_wr = newxprt->sc_sq_depth;
-	qp_attr.cap.max_recv_wr = newxprt->sc_max_requests;
+	qp_attr.cap.max_recv_wr = newxprt->sc_rq_depth;
 	qp_attr.cap.max_send_sge = newxprt->sc_max_sge;
 	qp_attr.cap.max_recv_sge = newxprt->sc_max_sge;
 	qp_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
@@ -978,7 +1108,7 @@ static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt)
 		"    cap.max_send_sge = %d\n"
 		"    cap.max_recv_sge = %d\n",
 		newxprt->sc_cm_id, newxprt->sc_pd,
-		newxprt->sc_cm_id->device, newxprt->sc_pd->device,
+		dev, newxprt->sc_pd->device,
 		qp_attr.cap.max_send_wr,
 		qp_attr.cap.max_recv_wr,
 		qp_attr.cap.max_send_sge,
@@ -1014,9 +1144,9 @@ static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt)
 	 *	of an RDMA_READ. IB does not.
 	 */
 	newxprt->sc_reader = rdma_read_chunk_lcl;
-	if (devattr.device_cap_flags & IB_DEVICE_MEM_MGT_EXTENSIONS) {
+	if (dev->attrs.device_cap_flags & IB_DEVICE_MEM_MGT_EXTENSIONS) {
 		newxprt->sc_frmr_pg_list_len =
-			devattr.max_fast_reg_page_list_len;
+			dev->attrs.max_fast_reg_page_list_len;
 		newxprt->sc_dev_caps |= SVCRDMA_DEVCAP_FAST_REG;
 		newxprt->sc_reader = rdma_read_chunk_frmr;
 	}
@@ -1024,44 +1154,16 @@ static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt)
 	/*
 	 * Determine if a DMA MR is required and if so, what privs are required
 	 */
-	if (!rdma_protocol_iwarp(newxprt->sc_cm_id->device,
-				 newxprt->sc_cm_id->port_num) &&
-	    !rdma_ib_or_roce(newxprt->sc_cm_id->device,
-			     newxprt->sc_cm_id->port_num))
+	if (!rdma_protocol_iwarp(dev, newxprt->sc_cm_id->port_num) &&
+	    !rdma_ib_or_roce(dev, newxprt->sc_cm_id->port_num))
 		goto errout;
 
-	if (!(newxprt->sc_dev_caps & SVCRDMA_DEVCAP_FAST_REG) ||
-	    !(devattr.device_cap_flags & IB_DEVICE_LOCAL_DMA_LKEY)) {
-		need_dma_mr = 1;
-		dma_mr_acc = IB_ACCESS_LOCAL_WRITE;
-		if (rdma_protocol_iwarp(newxprt->sc_cm_id->device,
-					newxprt->sc_cm_id->port_num) &&
-		    !(newxprt->sc_dev_caps & SVCRDMA_DEVCAP_FAST_REG))
-			dma_mr_acc |= IB_ACCESS_REMOTE_WRITE;
-	}
-
-	if (rdma_protocol_iwarp(newxprt->sc_cm_id->device,
-				newxprt->sc_cm_id->port_num))
+	if (rdma_protocol_iwarp(dev, newxprt->sc_cm_id->port_num))
 		newxprt->sc_dev_caps |= SVCRDMA_DEVCAP_READ_W_INV;
 
-	/* Create the DMA MR if needed, otherwise, use the DMA LKEY */
-	if (need_dma_mr) {
-		/* Register all of physical memory */
-		newxprt->sc_phys_mr =
-			ib_get_dma_mr(newxprt->sc_pd, dma_mr_acc);
-		if (IS_ERR(newxprt->sc_phys_mr)) {
-			dprintk("svcrdma: Failed to create DMA MR ret=%d\n",
-				ret);
-			goto errout;
-		}
-		newxprt->sc_dma_lkey = newxprt->sc_phys_mr->lkey;
-	} else
-		newxprt->sc_dma_lkey =
-			newxprt->sc_cm_id->device->local_dma_lkey;
-
 	/* Post receive buffers */
-	for (i = 0; i < newxprt->sc_max_requests; i++) {
-		ret = svc_rdma_post_recv(newxprt);
+	for (i = 0; i < newxprt->sc_rq_depth; i++) {
+		ret = svc_rdma_post_recv(newxprt, GFP_KERNEL);
 		if (ret) {
 			dprintk("svcrdma: failure posting receive buffers\n");
 			goto errout;
@@ -1160,12 +1262,14 @@ static void __svc_rdma_free(struct work_struct *work)
 {
 	struct svcxprt_rdma *rdma =
 		container_of(work, struct svcxprt_rdma, sc_work);
-	dprintk("svcrdma: svc_rdma_free(%p)\n", rdma);
+	struct svc_xprt *xprt = &rdma->sc_xprt;
+
+	dprintk("svcrdma: %s(%p)\n", __func__, rdma);
 
 	/* We should only be called from kref_put */
-	if (atomic_read(&rdma->sc_xprt.xpt_ref.refcount) != 0)
+	if (atomic_read(&xprt->xpt_ref.refcount) != 0)
 		pr_err("svcrdma: sc_xprt still in use? (%d)\n",
-		       atomic_read(&rdma->sc_xprt.xpt_ref.refcount));
+		       atomic_read(&xprt->xpt_ref.refcount));
 
 	/*
 	 * Destroy queued, but not processed read completions. Note
@@ -1193,15 +1297,22 @@ static void __svc_rdma_free(struct work_struct *work)
 	}
 
 	/* Warn if we leaked a resource or under-referenced */
-	if (atomic_read(&rdma->sc_ctxt_used) != 0)
+	if (rdma->sc_ctxt_used != 0)
 		pr_err("svcrdma: ctxt still in use? (%d)\n",
-		       atomic_read(&rdma->sc_ctxt_used));
+		       rdma->sc_ctxt_used);
 	if (atomic_read(&rdma->sc_dma_used) != 0)
 		pr_err("svcrdma: dma still in use? (%d)\n",
 		       atomic_read(&rdma->sc_dma_used));
 
-	/* De-allocate fastreg mr */
+	/* Final put of backchannel client transport */
+	if (xprt->xpt_bc_xprt) {
+		xprt_put(xprt->xpt_bc_xprt);
+		xprt->xpt_bc_xprt = NULL;
+	}
+
 	rdma_dealloc_frmr_q(rdma);
+	svc_rdma_destroy_ctxts(rdma);
+	svc_rdma_destroy_maps(rdma);
 
 	/* Destroy the QP if present (not a listener) */
 	if (rdma->sc_qp && !IS_ERR(rdma->sc_qp))
@@ -1213,9 +1324,6 @@ static void __svc_rdma_free(struct work_struct *work)
 	if (rdma->sc_rq_cq && !IS_ERR(rdma->sc_rq_cq))
 		ib_destroy_cq(rdma->sc_rq_cq);
 
-	if (rdma->sc_phys_mr && !IS_ERR(rdma->sc_phys_mr))
-		ib_dereg_mr(rdma->sc_phys_mr);
-
 	if (rdma->sc_pd && !IS_ERR(rdma->sc_pd))
 		ib_dealloc_pd(rdma->sc_pd);
 
@@ -1321,7 +1429,9 @@ void svc_rdma_send_error(struct svcxprt_rdma *xprt, struct rpcrdma_msg *rmsgp,
 	int length;
 	int ret;
 
-	p = alloc_page(GFP_KERNEL | __GFP_NOFAIL);
+	p = alloc_page(GFP_KERNEL);
+	if (!p)
+		return;
 	va = page_address(p);
 
 	/* XDR encode error */
@@ -1341,7 +1451,7 @@ void svc_rdma_send_error(struct svcxprt_rdma *xprt, struct rpcrdma_msg *rmsgp,
 		return;
 	}
 	atomic_inc(&xprt->sc_dma_used);
-	ctxt->sge[0].lkey = xprt->sc_dma_lkey;
+	ctxt->sge[0].lkey = xprt->sc_pd->local_dma_lkey;
 	ctxt->sge[0].length = length;
 
 	/* Prepare SEND WR */
diff --git a/net/sunrpc/xprtrdma/transport.c b/net/sunrpc/xprtrdma/transport.c
index 8c545f7d7..b1b009f10 100644
--- a/net/sunrpc/xprtrdma/transport.c
+++ b/net/sunrpc/xprtrdma/transport.c
@@ -63,7 +63,7 @@
  */
 
 static unsigned int xprt_rdma_slot_table_entries = RPCRDMA_DEF_SLOT_TABLE;
-static unsigned int xprt_rdma_max_inline_read = RPCRDMA_DEF_INLINE;
+unsigned int xprt_rdma_max_inline_read = RPCRDMA_DEF_INLINE;
 static unsigned int xprt_rdma_max_inline_write = RPCRDMA_DEF_INLINE;
 static unsigned int xprt_rdma_inline_write_padding;
 static unsigned int xprt_rdma_memreg_strategy = RPCRDMA_FRMR;
@@ -143,12 +143,7 @@ static struct ctl_table sunrpc_table[] = {
 
 #endif
 
-#define RPCRDMA_BIND_TO		(60U * HZ)
-#define RPCRDMA_INIT_REEST_TO	(5U * HZ)
-#define RPCRDMA_MAX_REEST_TO	(30U * HZ)
-#define RPCRDMA_IDLE_DISC_TO	(5U * 60 * HZ)
-
-static struct rpc_xprt_ops xprt_rdma_procs;	/* forward reference */
+static struct rpc_xprt_ops xprt_rdma_procs;	/*forward reference */
 
 static void
 xprt_rdma_format_addresses4(struct rpc_xprt *xprt, struct sockaddr *sap)
@@ -174,7 +169,7 @@ xprt_rdma_format_addresses6(struct rpc_xprt *xprt, struct sockaddr *sap)
 	xprt->address_strings[RPC_DISPLAY_NETID] = RPCBIND_NETID_RDMA6;
 }
 
-static void
+void
 xprt_rdma_format_addresses(struct rpc_xprt *xprt, struct sockaddr *sap)
 {
 	char buf[128];
@@ -203,7 +198,7 @@ xprt_rdma_format_addresses(struct rpc_xprt *xprt, struct sockaddr *sap)
 	xprt->address_strings[RPC_DISPLAY_PROTO] = "rdma";
 }
 
-static void
+void
 xprt_rdma_free_addresses(struct rpc_xprt *xprt)
 {
 	unsigned int i;
@@ -499,7 +494,7 @@ xprt_rdma_allocate(struct rpc_task *task, size_t size)
 	if (req == NULL)
 		return NULL;
 
-	flags = GFP_NOIO | __GFP_NOWARN;
+	flags = RPCRDMA_DEF_GFP;
 	if (RPC_IS_SWAPPER(task))
 		flags = __GFP_MEMALLOC | GFP_NOWAIT | __GFP_NOWARN;
 
@@ -576,6 +571,9 @@ xprt_rdma_free(void *buffer)
 
 	rb = container_of(buffer, struct rpcrdma_regbuf, rg_base[0]);
 	req = rb->rg_owner;
+	if (req->rl_backchannel)
+		return;
+
 	r_xprt = container_of(req->rl_buffer, struct rpcrdma_xprt, rx_buf);
 
 	dprintk("RPC:       %s: called on 0x%p\n", __func__, req->rl_reply);
@@ -639,7 +637,7 @@ drop_connection:
 	return -ENOTCONN;	/* implies disconnect */
 }
 
-static void xprt_rdma_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
+void xprt_rdma_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
 {
 	struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 	long idle_time = 0;
@@ -740,6 +738,11 @@ void xprt_rdma_cleanup(void)
 
 	rpcrdma_destroy_wq();
 	frwr_destroy_recovery_wq();
+
+	rc = xprt_unregister_transport(&xprt_rdma_bc);
+	if (rc)
+		dprintk("RPC:       %s: xprt_unregister(bc) returned %i\n",
+			__func__, rc);
 }
 
 int xprt_rdma_init(void)
@@ -763,6 +766,14 @@ int xprt_rdma_init(void)
 		return rc;
 	}
 
+	rc = xprt_register_transport(&xprt_rdma_bc);
+	if (rc) {
+		xprt_unregister_transport(&xprt_rdma);
+		rpcrdma_destroy_wq();
+		frwr_destroy_recovery_wq();
+		return rc;
+	}
+
 	dprintk("RPCRDMA Module Init, register RPC RDMA transport\n");
 
 	dprintk("Defaults:\n");
diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index eadd16551..878f1bfb1 100644
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -462,7 +462,6 @@ int
 rpcrdma_ia_open(struct rpcrdma_xprt *xprt, struct sockaddr *addr, int memreg)
 {
 	struct rpcrdma_ia *ia = &xprt->rx_ia;
-	struct ib_device_attr *devattr = &ia->ri_devattr;
 	int rc;
 
 	ia->ri_dma_mr = NULL;
@@ -482,16 +481,10 @@ rpcrdma_ia_open(struct rpcrdma_xprt *xprt, struct sockaddr *addr, int memreg)
 		goto out2;
 	}
 
-	rc = ib_query_device(ia->ri_device, devattr);
-	if (rc) {
-		dprintk("RPC:       %s: ib_query_device failed %d\n",
-			__func__, rc);
-		goto out3;
-	}
-
 	if (memreg == RPCRDMA_FRMR) {
-		if (!(devattr->device_cap_flags & IB_DEVICE_MEM_MGT_EXTENSIONS) ||
-		    (devattr->max_fast_reg_page_list_len == 0)) {
+		if (!(ia->ri_device->attrs.device_cap_flags &
+				IB_DEVICE_MEM_MGT_EXTENSIONS) ||
+		    (ia->ri_device->attrs.max_fast_reg_page_list_len == 0)) {
 			dprintk("RPC:       %s: FRMR registration "
 				"not supported by HCA\n", __func__);
 			memreg = RPCRDMA_MTHCAFMR;
@@ -566,24 +559,23 @@ int
 rpcrdma_ep_create(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia,
 				struct rpcrdma_create_data_internal *cdata)
 {
-	struct ib_device_attr *devattr = &ia->ri_devattr;
 	struct ib_cq *sendcq, *recvcq;
 	struct ib_cq_init_attr cq_attr = {};
 	unsigned int max_qp_wr;
 	int rc, err;
 
-	if (devattr->max_sge < RPCRDMA_MAX_IOVS) {
+	if (ia->ri_device->attrs.max_sge < RPCRDMA_MAX_IOVS) {
 		dprintk("RPC:       %s: insufficient sge's available\n",
 			__func__);
 		return -ENOMEM;
 	}
 
-	if (devattr->max_qp_wr <= RPCRDMA_BACKWARD_WRS) {
+	if (ia->ri_device->attrs.max_qp_wr <= RPCRDMA_BACKWARD_WRS) {
 		dprintk("RPC:       %s: insufficient wqe's available\n",
 			__func__);
 		return -ENOMEM;
 	}
-	max_qp_wr = devattr->max_qp_wr - RPCRDMA_BACKWARD_WRS;
+	max_qp_wr = ia->ri_device->attrs.max_qp_wr - RPCRDMA_BACKWARD_WRS;
 
 	/* check provider's send/recv wr limits */
 	if (cdata->max_requests > max_qp_wr)
@@ -616,10 +608,8 @@ rpcrdma_ep_create(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia,
 
 	/* set trigger for requesting send completion */
 	ep->rep_cqinit = ep->rep_attr.cap.max_send_wr/2 - 1;
-	if (ep->rep_cqinit > RPCRDMA_MAX_UNSIGNALED_SENDS)
-		ep->rep_cqinit = RPCRDMA_MAX_UNSIGNALED_SENDS;
-	else if (ep->rep_cqinit <= 2)
-		ep->rep_cqinit = 0;
+	if (ep->rep_cqinit <= 2)
+		ep->rep_cqinit = 0;	/* always signal? */
 	INIT_CQCOUNT(ep);
 	init_waitqueue_head(&ep->rep_connect_wait);
 	INIT_DELAYED_WORK(&ep->rep_connect_worker, rpcrdma_connect_worker);
@@ -670,11 +660,11 @@ rpcrdma_ep_create(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia,
 
 	/* Client offers RDMA Read but does not initiate */
 	ep->rep_remote_cma.initiator_depth = 0;
-	if (devattr->max_qp_rd_atom > 32)	/* arbitrary but <= 255 */
+	if (ia->ri_device->attrs.max_qp_rd_atom > 32)	/* arbitrary but <= 255 */
 		ep->rep_remote_cma.responder_resources = 32;
 	else
 		ep->rep_remote_cma.responder_resources =
-						devattr->max_qp_rd_atom;
+						ia->ri_device->attrs.max_qp_rd_atom;
 
 	ep->rep_remote_cma.retry_count = 7;
 	ep->rep_remote_cma.flow_control = 0;
@@ -852,10 +842,11 @@ retry:
 
 		if (extras) {
 			rc = rpcrdma_ep_post_extra_recv(r_xprt, extras);
-			if (rc)
+			if (rc) {
 				pr_warn("%s: rpcrdma_ep_post_extra_recv: %i\n",
 					__func__, rc);
 				rc = 0;
+			}
 		}
 	}
 
@@ -1337,15 +1328,14 @@ rpcrdma_ep_post_extra_recv(struct rpcrdma_xprt *r_xprt, unsigned int count)
 	struct rpcrdma_ia *ia = &r_xprt->rx_ia;
 	struct rpcrdma_ep *ep = &r_xprt->rx_ep;
 	struct rpcrdma_rep *rep;
-	unsigned long flags;
 	int rc;
 
 	while (count--) {
-		spin_lock_irqsave(&buffers->rb_lock, flags);
+		spin_lock(&buffers->rb_lock);
 		if (list_empty(&buffers->rb_recv_bufs))
 			goto out_reqbuf;
 		rep = rpcrdma_buffer_get_rep_locked(buffers);
-		spin_unlock_irqrestore(&buffers->rb_lock, flags);
+		spin_unlock(&buffers->rb_lock);
 
 		rc = rpcrdma_ep_post_recv(ia, ep, rep);
 		if (rc)
@@ -1355,7 +1345,7 @@ rpcrdma_ep_post_extra_recv(struct rpcrdma_xprt *r_xprt, unsigned int count)
 	return 0;
 
 out_reqbuf:
-	spin_unlock_irqrestore(&buffers->rb_lock, flags);
+	spin_unlock(&buffers->rb_lock);
 	pr_warn("%s: no extra receive buffers\n", __func__);
 	return -ENOMEM;
 
diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h
index ac7f8d4f6..38fe11b09 100644
--- a/net/sunrpc/xprtrdma/xprt_rdma.h
+++ b/net/sunrpc/xprtrdma/xprt_rdma.h
@@ -55,6 +55,11 @@
 #define RDMA_RESOLVE_TIMEOUT	(5000)	/* 5 seconds */
 #define RDMA_CONNECT_RETRY_MAX	(2)	/* retries if no listener backlog */
 
+#define RPCRDMA_BIND_TO		(60U * HZ)
+#define RPCRDMA_INIT_REEST_TO	(5U * HZ)
+#define RPCRDMA_MAX_REEST_TO	(30U * HZ)
+#define RPCRDMA_IDLE_DISC_TO	(5U * 60 * HZ)
+
 /*
  * Interface Adapter -- one per transport instance
  */
@@ -68,7 +73,6 @@ struct rpcrdma_ia {
 	struct completion	ri_done;
 	int			ri_async_rc;
 	unsigned int		ri_max_frmr_depth;
-	struct ib_device_attr	ri_devattr;
 	struct ib_qp_attr	ri_qp_attr;
 	struct ib_qp_init_attr	ri_qp_init_attr;
 };
@@ -88,12 +92,6 @@ struct rpcrdma_ep {
 	struct delayed_work	rep_connect_worker;
 };
 
-/*
- * Force a signaled SEND Work Request every so often,
- * in case the provider needs to do some housekeeping.
- */
-#define RPCRDMA_MAX_UNSIGNALED_SENDS	(32)
-
 #define INIT_CQCOUNT(ep) atomic_set(&(ep)->rep_cqcount, (ep)->rep_cqinit)
 #define DECR_CQCOUNT(ep) atomic_sub_return(1, &(ep)->rep_cqcount)
 
@@ -148,6 +146,8 @@ rdmab_to_msg(struct rpcrdma_regbuf *rb)
 	return (struct rpcrdma_msg *)rb->rg_base;
 }
 
+#define RPCRDMA_DEF_GFP		(GFP_NOIO | __GFP_NOWARN)
+
 /*
  * struct rpcrdma_rep -- this structure encapsulates state required to recv
  * and complete a reply, asychronously. It needs several pieces of
@@ -207,6 +207,12 @@ struct rpcrdma_frmr {
 	enum rpcrdma_frmr_state		fr_state;
 	struct work_struct		fr_work;
 	struct rpcrdma_xprt		*fr_xprt;
+	bool				fr_waiter;
+	struct completion		fr_linv_done;;
+	union {
+		struct ib_reg_wr	fr_regwr;
+		struct ib_send_wr	fr_invwr;
+	};
 };
 
 struct rpcrdma_fmr {
@@ -309,6 +315,8 @@ struct rpcrdma_buffer {
 	u32			rb_bc_srv_max_requests;
 	spinlock_t		rb_reqslock;	/* protect rb_allreqs */
 	struct list_head	rb_allreqs;
+
+	u32			rb_bc_max_requests;
 };
 #define rdmab_to_ia(b) (&container_of((b), struct rpcrdma_xprt, rx_buf)->rx_ia)
 
@@ -364,6 +372,8 @@ struct rpcrdma_xprt;
 struct rpcrdma_memreg_ops {
 	int		(*ro_map)(struct rpcrdma_xprt *,
 				  struct rpcrdma_mr_seg *, int, bool);
+	void		(*ro_unmap_sync)(struct rpcrdma_xprt *,
+					 struct rpcrdma_req *);
 	int		(*ro_unmap)(struct rpcrdma_xprt *,
 				    struct rpcrdma_mr_seg *);
 	int		(*ro_open)(struct rpcrdma_ia *,
@@ -514,6 +524,10 @@ int rpcrdma_marshal_req(struct rpc_rqst *);
 
 /* RPC/RDMA module init - xprtrdma/transport.c
  */
+extern unsigned int xprt_rdma_max_inline_read;
+void xprt_rdma_format_addresses(struct rpc_xprt *xprt, struct sockaddr *sap);
+void xprt_rdma_free_addresses(struct rpc_xprt *xprt);
+void xprt_rdma_print_stats(struct rpc_xprt *xprt, struct seq_file *seq);
 int xprt_rdma_init(void);
 void xprt_rdma_cleanup(void);
 
@@ -529,11 +543,6 @@ void xprt_rdma_bc_free_rqst(struct rpc_rqst *);
 void xprt_rdma_bc_destroy(struct rpc_xprt *, unsigned int);
 #endif	/* CONFIG_SUNRPC_BACKCHANNEL */
 
-/* Temporary NFS request map cache. Created in svc_rdma.c  */
-extern struct kmem_cache *svc_rdma_map_cachep;
-/* WR context cache. Created in svc_rdma.c  */
-extern struct kmem_cache *svc_rdma_ctxt_cachep;
-/* Workqueue created in svc_rdma.c */
-extern struct workqueue_struct *svc_rdma_wq;
+extern struct xprt_class xprt_rdma_bc;
 
 #endif				/* _LINUX_SUNRPC_XPRT_RDMA_H */