These changes are the raw update to linux-4.4.6-rt14. Kernel sources

are taken from kernel.org, and rt patch from the rt wiki download page.

During the rebasing, the following patch collided:

Force tick interrupt and get rid of softirq magic(I70131fb85).

Collisions have been removed because its logic was found on the
source already.

Change-Id: I7f57a4081d9deaa0d9ccfc41a6c8daccdee3b769
Signed-off-by: José Pekkarinen <jose.pekkarinen@nokia.com>

33 files changed, 2746 insertions, 1926 deletions

diff --git a/kernel/net/sunrpc/Kconfig b/kernel/net/sunrpc/Kconfig
index 9068e72aa..04ce2c0b6 100644
--- a/kernel/net/sunrpc/Kconfig
+++ b/kernel/net/sunrpc/Kconfig
@@ -48,28 +48,16 @@ config SUNRPC_DEBUG
 
 	  If unsure, say Y.
 
-config SUNRPC_XPRT_RDMA_CLIENT
-	tristate "RPC over RDMA Client Support"
+config SUNRPC_XPRT_RDMA
+	tristate "RPC-over-RDMA transport"
 	depends on SUNRPC && INFINIBAND && INFINIBAND_ADDR_TRANS
 	default SUNRPC && INFINIBAND
 	help
-	  This option allows the NFS client to support an RDMA-enabled
-	  transport.
+	  This option allows the NFS client and server to use RDMA
+	  transports (InfiniBand, iWARP, or RoCE).
 
-	  To compile RPC client RDMA transport support as a module,
-	  choose M here: the module will be called xprtrdma.
+	  To compile this support as a module, choose M. The module
+	  will be called rpcrdma.ko.
 
-	  If unsure, say N.
-
-config SUNRPC_XPRT_RDMA_SERVER
-	tristate "RPC over RDMA Server Support"
-	depends on SUNRPC && INFINIBAND && INFINIBAND_ADDR_TRANS
-	default SUNRPC && INFINIBAND
-	help
-	  This option allows the NFS server to support an RDMA-enabled
-	  transport.
-
-	  To compile RPC server RDMA transport support as a module,
-	  choose M here: the module will be called svcrdma.
-
-	  If unsure, say N.
+	  If unsure, or you know there is no RDMA capability on your
+	  hardware platform, say N.
diff --git a/kernel/net/sunrpc/Makefile b/kernel/net/sunrpc/Makefile
index 15e6f6c23..b512fbd9d 100644
--- a/kernel/net/sunrpc/Makefile
+++ b/kernel/net/sunrpc/Makefile
@@ -5,8 +5,7 @@
 
 obj-$(CONFIG_SUNRPC) += sunrpc.o
 obj-$(CONFIG_SUNRPC_GSS) += auth_gss/
-
-obj-y += xprtrdma/
+obj-$(CONFIG_SUNRPC_XPRT_RDMA) += xprtrdma/
 
 sunrpc-y := clnt.o xprt.o socklib.o xprtsock.o sched.o \
 	    auth.o auth_null.o auth_unix.o auth_generic.o \
@@ -15,6 +14,6 @@ sunrpc-y := clnt.o xprt.o socklib.o xprtsock.o sched.o \
 	    sunrpc_syms.o cache.o rpc_pipe.o \
 	    svc_xprt.o
 sunrpc-$(CONFIG_SUNRPC_DEBUG) += debugfs.o
-sunrpc-$(CONFIG_SUNRPC_BACKCHANNEL) += backchannel_rqst.o bc_svc.o
+sunrpc-$(CONFIG_SUNRPC_BACKCHANNEL) += backchannel_rqst.o
 sunrpc-$(CONFIG_PROC_FS) += stats.o
 sunrpc-$(CONFIG_SYSCTL) += sysctl.o
diff --git a/kernel/net/sunrpc/auth.c b/kernel/net/sunrpc/auth.c
index 47f38be41..02f53674d 100644
--- a/kernel/net/sunrpc/auth.c
+++ b/kernel/net/sunrpc/auth.c
@@ -72,7 +72,7 @@ static int param_get_hashtbl_sz(char *buffer, const struct kernel_param *kp)
 
 #define param_check_hashtbl_sz(name, p) __param_check(name, p, unsigned int);
 
-static struct kernel_param_ops param_ops_hashtbl_sz = {
+static const struct kernel_param_ops param_ops_hashtbl_sz = {
 	.set = param_set_hashtbl_sz,
 	.get = param_get_hashtbl_sz,
 };
diff --git a/kernel/net/sunrpc/auth_gss/auth_gss.c b/kernel/net/sunrpc/auth_gss/auth_gss.c
index dace13d76..799e65b94 100644
--- a/kernel/net/sunrpc/auth_gss/auth_gss.c
+++ b/kernel/net/sunrpc/auth_gss/auth_gss.c
@@ -1411,17 +1411,16 @@ gss_key_timeout(struct rpc_cred *rc)
 {
 	struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
 	struct gss_cl_ctx *ctx;
-	unsigned long now = jiffies;
-	unsigned long expire;
+	unsigned long timeout = jiffies + (gss_key_expire_timeo * HZ);
+	int ret = 0;
 
 	rcu_read_lock();
 	ctx = rcu_dereference(gss_cred->gc_ctx);
-	if (ctx)
-		expire = ctx->gc_expiry - (gss_key_expire_timeo * HZ);
+	if (!ctx || time_after(timeout, ctx->gc_expiry))
+		ret = -EACCES;
 	rcu_read_unlock();
-	if (!ctx || time_after(now, expire))
-		return -EACCES;
-	return 0;
+
+	return ret;
 }
 
 static int
diff --git a/kernel/net/sunrpc/auth_gss/gss_krb5_crypto.c b/kernel/net/sunrpc/auth_gss/gss_krb5_crypto.c
index b5408e8a3..fee3c15a4 100644
--- a/kernel/net/sunrpc/auth_gss/gss_krb5_crypto.c
+++ b/kernel/net/sunrpc/auth_gss/gss_krb5_crypto.c
@@ -881,9 +881,7 @@ krb5_rc4_setup_seq_key(struct krb5_ctx *kctx, struct crypto_blkcipher *cipher,
 	if (err)
 		goto out_err;
 
-	sg_init_table(sg, 1);
-	sg_set_buf(sg, &zeroconstant, 4);
-
+	sg_init_one(sg, &zeroconstant, 4);
 	err = crypto_hash_digest(&desc, sg, 4, Kseq);
 	if (err)
 		goto out_err;
@@ -951,9 +949,7 @@ krb5_rc4_setup_enc_key(struct krb5_ctx *kctx, struct crypto_blkcipher *cipher,
 	if (err)
 		goto out_err;
 
-	sg_init_table(sg, 1);
-	sg_set_buf(sg, zeroconstant, 4);
-
+	sg_init_one(sg, zeroconstant, 4);
 	err = crypto_hash_digest(&desc, sg, 4, Kcrypt);
 	if (err)
 		goto out_err;
diff --git a/kernel/net/sunrpc/auth_unix.c b/kernel/net/sunrpc/auth_unix.c
index 4feda2d0a..548240dd1 100644
--- a/kernel/net/sunrpc/auth_unix.c
+++ b/kernel/net/sunrpc/auth_unix.c
@@ -23,7 +23,7 @@ struct unx_cred {
 };
 #define uc_uid			uc_base.cr_uid
 
-#define UNX_WRITESLACK		(21 + (UNX_MAXNODENAME >> 2))
+#define UNX_WRITESLACK		(21 + XDR_QUADLEN(UNX_MAXNODENAME))
 
 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 # define RPCDBG_FACILITY	RPCDBG_AUTH
diff --git a/kernel/net/sunrpc/backchannel_rqst.c b/kernel/net/sunrpc/backchannel_rqst.c
index 28504dfd3..229956bf8 100644
--- a/kernel/net/sunrpc/backchannel_rqst.c
+++ b/kernel/net/sunrpc/backchannel_rqst.c
@@ -37,16 +37,18 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 static inline int xprt_need_to_requeue(struct rpc_xprt *xprt)
 {
-	return xprt->bc_alloc_count > 0;
+	return xprt->bc_alloc_count < atomic_read(&xprt->bc_free_slots);
 }
 
 static inline void xprt_inc_alloc_count(struct rpc_xprt *xprt, unsigned int n)
 {
+	atomic_add(n, &xprt->bc_free_slots);
 	xprt->bc_alloc_count += n;
 }
 
 static inline int xprt_dec_alloc_count(struct rpc_xprt *xprt, unsigned int n)
 {
+	atomic_sub(n, &xprt->bc_free_slots);
 	return xprt->bc_alloc_count -= n;
 }
 
@@ -67,6 +69,55 @@ static void xprt_free_allocation(struct rpc_rqst *req)
 	kfree(req);
 }
 
+static int xprt_alloc_xdr_buf(struct xdr_buf *buf, gfp_t gfp_flags)
+{
+	struct page *page;
+	/* Preallocate one XDR receive buffer */
+	page = alloc_page(gfp_flags);
+	if (page == NULL)
+		return -ENOMEM;
+	buf->head[0].iov_base = page_address(page);
+	buf->head[0].iov_len = PAGE_SIZE;
+	buf->tail[0].iov_base = NULL;
+	buf->tail[0].iov_len = 0;
+	buf->page_len = 0;
+	buf->len = 0;
+	buf->buflen = PAGE_SIZE;
+	return 0;
+}
+
+static
+struct rpc_rqst *xprt_alloc_bc_req(struct rpc_xprt *xprt, gfp_t gfp_flags)
+{
+	struct rpc_rqst *req;
+
+	/* Pre-allocate one backchannel rpc_rqst */
+	req = kzalloc(sizeof(*req), gfp_flags);
+	if (req == NULL)
+		return NULL;
+
+	req->rq_xprt = xprt;
+	INIT_LIST_HEAD(&req->rq_list);
+	INIT_LIST_HEAD(&req->rq_bc_list);
+
+	/* Preallocate one XDR receive buffer */
+	if (xprt_alloc_xdr_buf(&req->rq_rcv_buf, gfp_flags) < 0) {
+		printk(KERN_ERR "Failed to create bc receive xbuf\n");
+		goto out_free;
+	}
+	req->rq_rcv_buf.len = PAGE_SIZE;
+
+	/* Preallocate one XDR send buffer */
+	if (xprt_alloc_xdr_buf(&req->rq_snd_buf, gfp_flags) < 0) {
+		printk(KERN_ERR "Failed to create bc snd xbuf\n");
+		goto out_free;
+	}
+	return req;
+out_free:
+	xprt_free_allocation(req);
+	return NULL;
+}
+
 /*
  * Preallocate up to min_reqs structures and related buffers for use
  * by the backchannel.  This function can be called multiple times
@@ -87,9 +138,15 @@ static void xprt_free_allocation(struct rpc_rqst *req)
  */
 int xprt_setup_backchannel(struct rpc_xprt *xprt, unsigned int min_reqs)
 {
-	struct page *page_rcv = NULL, *page_snd = NULL;
-	struct xdr_buf *xbufp = NULL;
-	struct rpc_rqst *req, *tmp;
+	if (!xprt->ops->bc_setup)
+		return 0;
+	return xprt->ops->bc_setup(xprt, min_reqs);
+}
+EXPORT_SYMBOL_GPL(xprt_setup_backchannel);
+
+int xprt_setup_bc(struct rpc_xprt *xprt, unsigned int min_reqs)
+{
+	struct rpc_rqst *req;
 	struct list_head tmp_list;
 	int i;
 
@@ -106,7 +163,7 @@ int xprt_setup_backchannel(struct rpc_xprt *xprt, unsigned int min_reqs)
 	INIT_LIST_HEAD(&tmp_list);
 	for (i = 0; i < min_reqs; i++) {
 		/* Pre-allocate one backchannel rpc_rqst */
-		req = kzalloc(sizeof(struct rpc_rqst), GFP_KERNEL);
+		req = xprt_alloc_bc_req(xprt, GFP_KERNEL);
 		if (req == NULL) {
 			printk(KERN_ERR "Failed to create bc rpc_rqst\n");
 			goto out_free;
@@ -115,41 +172,6 @@ int xprt_setup_backchannel(struct rpc_xprt *xprt, unsigned int min_reqs)
 		/* Add the allocated buffer to the tmp list */
 		dprintk("RPC:       adding req= %p\n", req);
 		list_add(&req->rq_bc_pa_list, &tmp_list);
-
-		req->rq_xprt = xprt;
-		INIT_LIST_HEAD(&req->rq_list);
-		INIT_LIST_HEAD(&req->rq_bc_list);
-
-		/* Preallocate one XDR receive buffer */
-		page_rcv = alloc_page(GFP_KERNEL);
-		if (page_rcv == NULL) {
-			printk(KERN_ERR "Failed to create bc receive xbuf\n");
-			goto out_free;
-		}
-		xbufp = &req->rq_rcv_buf;
-		xbufp->head[0].iov_base = page_address(page_rcv);
-		xbufp->head[0].iov_len = PAGE_SIZE;
-		xbufp->tail[0].iov_base = NULL;
-		xbufp->tail[0].iov_len = 0;
-		xbufp->page_len = 0;
-		xbufp->len = PAGE_SIZE;
-		xbufp->buflen = PAGE_SIZE;
-
-		/* Preallocate one XDR send buffer */
-		page_snd = alloc_page(GFP_KERNEL);
-		if (page_snd == NULL) {
-			printk(KERN_ERR "Failed to create bc snd xbuf\n");
-			goto out_free;
-		}
-
-		xbufp = &req->rq_snd_buf;
-		xbufp->head[0].iov_base = page_address(page_snd);
-		xbufp->head[0].iov_len = 0;
-		xbufp->tail[0].iov_base = NULL;
-		xbufp->tail[0].iov_len = 0;
-		xbufp->page_len = 0;
-		xbufp->len = 0;
-		xbufp->buflen = PAGE_SIZE;
 	}
 
 	/*
@@ -167,7 +189,10 @@ out_free:
 	/*
 	 * Memory allocation failed, free the temporary list
 	 */
-	list_for_each_entry_safe(req, tmp, &tmp_list, rq_bc_pa_list) {
+	while (!list_empty(&tmp_list)) {
+		req = list_first_entry(&tmp_list,
+				struct rpc_rqst,
+				rq_bc_pa_list);
 		list_del(&req->rq_bc_pa_list);
 		xprt_free_allocation(req);
 	}
@@ -175,7 +200,6 @@ out_free:
 	dprintk("RPC:       setup backchannel transport failed\n");
 	return -ENOMEM;
 }
-EXPORT_SYMBOL_GPL(xprt_setup_backchannel);
 
 /**
  * xprt_destroy_backchannel - Destroys the backchannel preallocated structures.
@@ -188,6 +212,13 @@ EXPORT_SYMBOL_GPL(xprt_setup_backchannel);
  */
 void xprt_destroy_backchannel(struct rpc_xprt *xprt, unsigned int max_reqs)
 {
+	if (xprt->ops->bc_destroy)
+		xprt->ops->bc_destroy(xprt, max_reqs);
+}
+EXPORT_SYMBOL_GPL(xprt_destroy_backchannel);
+
+void xprt_destroy_bc(struct rpc_xprt *xprt, unsigned int max_reqs)
+{
 	struct rpc_rqst *req = NULL, *tmp = NULL;
 
 	dprintk("RPC:        destroy backchannel transport\n");
@@ -210,16 +241,21 @@ out:
 	dprintk("RPC:        backchannel list empty= %s\n",
 		list_empty(&xprt->bc_pa_list) ? "true" : "false");
 }
-EXPORT_SYMBOL_GPL(xprt_destroy_backchannel);
 
 static struct rpc_rqst *xprt_alloc_bc_request(struct rpc_xprt *xprt, __be32 xid)
 {
 	struct rpc_rqst *req = NULL;
 
 	dprintk("RPC:       allocate a backchannel request\n");
-	if (list_empty(&xprt->bc_pa_list))
+	if (atomic_read(&xprt->bc_free_slots) <= 0)
 		goto not_found;
-
+	if (list_empty(&xprt->bc_pa_list)) {
+		req = xprt_alloc_bc_req(xprt, GFP_ATOMIC);
+		if (!req)
+			goto not_found;
+		list_add_tail(&req->rq_bc_pa_list, &xprt->bc_pa_list);
+		xprt->bc_alloc_count++;
+	}
 	req = list_first_entry(&xprt->bc_pa_list, struct rpc_rqst,
 				rq_bc_pa_list);
 	req->rq_reply_bytes_recvd = 0;
@@ -241,15 +277,32 @@ void xprt_free_bc_request(struct rpc_rqst *req)
 {
 	struct rpc_xprt *xprt = req->rq_xprt;
 
+	xprt->ops->bc_free_rqst(req);
+}
+
+void xprt_free_bc_rqst(struct rpc_rqst *req)
+{
+	struct rpc_xprt *xprt = req->rq_xprt;
+
 	dprintk("RPC:       free backchannel req=%p\n", req);
 
 	req->rq_connect_cookie = xprt->connect_cookie - 1;
 	smp_mb__before_atomic();
-	WARN_ON_ONCE(!test_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state));
 	clear_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state);
 	smp_mb__after_atomic();
 
-	if (!xprt_need_to_requeue(xprt)) {
+	/*
+	 * Return it to the list of preallocations so that it
+	 * may be reused by a new callback request.
+	 */
+	spin_lock_bh(&xprt->bc_pa_lock);
+	if (xprt_need_to_requeue(xprt)) {
+		list_add_tail(&req->rq_bc_pa_list, &xprt->bc_pa_list);
+		xprt->bc_alloc_count++;
+		req = NULL;
+	}
+	spin_unlock_bh(&xprt->bc_pa_lock);
+	if (req != NULL) {
 		/*
 		 * The last remaining session was destroyed while this
 		 * entry was in use.  Free the entry and don't attempt
@@ -260,14 +313,6 @@ void xprt_free_bc_request(struct rpc_rqst *req)
 		xprt_free_allocation(req);
 		return;
 	}
-
-	/*
-	 * Return it to the list of preallocations so that it
-	 * may be reused by a new callback request.
-	 */
-	spin_lock_bh(&xprt->bc_pa_lock);
-	list_add_tail(&req->rq_bc_pa_list, &xprt->bc_pa_list);
-	spin_unlock_bh(&xprt->bc_pa_lock);
 }
 
 /*
@@ -311,6 +356,7 @@ void xprt_complete_bc_request(struct rpc_rqst *req, uint32_t copied)
 
 	spin_lock(&xprt->bc_pa_lock);
 	list_del(&req->rq_bc_pa_list);
+	xprt_dec_alloc_count(xprt, 1);
 	spin_unlock(&xprt->bc_pa_lock);
 
 	req->rq_private_buf.len = copied;
diff --git a/kernel/net/sunrpc/bc_svc.c b/kernel/net/sunrpc/bc_svc.c
deleted file mode 100644
index 15c7a8a1c..000000000
--- a/kernel/net/sunrpc/bc_svc.c
+++ /dev/null
@@ -1,63 +0,0 @@
-/******************************************************************************
-
-(c) 2007 Network Appliance, Inc.  All Rights Reserved.
-(c) 2009 NetApp.  All Rights Reserved.
-
-NetApp provides this source code under the GPL v2 License.
-The GPL v2 license is available at
-http://opensource.org/licenses/gpl-license.php.
-
-THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
-CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
-EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
-PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
-PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
-LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
-NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
-SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-******************************************************************************/
-
-/*
- * The NFSv4.1 callback service helper routines.
- * They implement the transport level processing required to send the
- * reply over an existing open connection previously established by the client.
- */
-
-#include <linux/module.h>
-
-#include <linux/sunrpc/xprt.h>
-#include <linux/sunrpc/sched.h>
-#include <linux/sunrpc/bc_xprt.h>
-
-#define RPCDBG_FACILITY	RPCDBG_SVCDSP
-
-/* Empty callback ops */
-static const struct rpc_call_ops nfs41_callback_ops = {
-};
-
-
-/*
- * Send the callback reply
- */
-int bc_send(struct rpc_rqst *req)
-{
-	struct rpc_task *task;
-	int ret;
-
-	dprintk("RPC:       bc_send req= %p\n", req);
-	task = rpc_run_bc_task(req, &nfs41_callback_ops);
-	if (IS_ERR(task))
-		ret = PTR_ERR(task);
-	else {
-		WARN_ON_ONCE(atomic_read(&task->tk_count) != 1);
-		ret = task->tk_status;
-		rpc_put_task(task);
-	}
-	dprintk("RPC:       bc_send ret= %d\n", ret);
-	return ret;
-}
-
diff --git a/kernel/net/sunrpc/cache.c b/kernel/net/sunrpc/cache.c
index 2928afffb..21e203531 100644
--- a/kernel/net/sunrpc/cache.c
+++ b/kernel/net/sunrpc/cache.c
@@ -41,28 +41,30 @@
 static bool cache_defer_req(struct cache_req *req, struct cache_head *item);
 static void cache_revisit_request(struct cache_head *item);
 
-static void cache_init(struct cache_head *h)
+static void cache_init(struct cache_head *h, struct cache_detail *detail)
 {
 	time_t now = seconds_since_boot();
-	h->next = NULL;
+	INIT_HLIST_NODE(&h->cache_list);
 	h->flags = 0;
 	kref_init(&h->ref);
 	h->expiry_time = now + CACHE_NEW_EXPIRY;
+	if (now <= detail->flush_time)
+		/* ensure it isn't already expired */
+		now = detail->flush_time + 1;
 	h->last_refresh = now;
 }
 
 struct cache_head *sunrpc_cache_lookup(struct cache_detail *detail,
 				       struct cache_head *key, int hash)
 {
-	struct cache_head **head,  **hp;
-	struct cache_head *new = NULL, *freeme = NULL;
+	struct cache_head *new = NULL, *freeme = NULL, *tmp = NULL;
+	struct hlist_head *head;
 
 	head = &detail->hash_table[hash];
 
 	read_lock(&detail->hash_lock);
 
-	for (hp=head; *hp != NULL ; hp = &(*hp)->next) {
-		struct cache_head *tmp = *hp;
+	hlist_for_each_entry(tmp, head, cache_list) {
 		if (detail->match(tmp, key)) {
 			if (cache_is_expired(detail, tmp))
 				/* This entry is expired, we will discard it. */
@@ -82,18 +84,16 @@ struct cache_head *sunrpc_cache_lookup(struct cache_detail *detail,
 	 * we might get lose if we need to
 	 * cache_put it soon.
 	 */
-	cache_init(new);
+	cache_init(new, detail);
 	detail->init(new, key);
 
 	write_lock(&detail->hash_lock);
 
 	/* check if entry appeared while we slept */
-	for (hp=head; *hp != NULL ; hp = &(*hp)->next) {
-		struct cache_head *tmp = *hp;
+	hlist_for_each_entry(tmp, head, cache_list) {
 		if (detail->match(tmp, key)) {
 			if (cache_is_expired(detail, tmp)) {
-				*hp = tmp->next;
-				tmp->next = NULL;
+				hlist_del_init(&tmp->cache_list);
 				detail->entries --;
 				freeme = tmp;
 				break;
@@ -104,8 +104,8 @@ struct cache_head *sunrpc_cache_lookup(struct cache_detail *detail,
 			return tmp;
 		}
 	}
-	new->next = *head;
-	*head = new;
+
+	hlist_add_head(&new->cache_list, head);
 	detail->entries++;
 	cache_get(new);
 	write_unlock(&detail->hash_lock);
@@ -119,10 +119,15 @@ EXPORT_SYMBOL_GPL(sunrpc_cache_lookup);
 
 static void cache_dequeue(struct cache_detail *detail, struct cache_head *ch);
 
-static void cache_fresh_locked(struct cache_head *head, time_t expiry)
+static void cache_fresh_locked(struct cache_head *head, time_t expiry,
+			       struct cache_detail *detail)
 {
+	time_t now = seconds_since_boot();
+	if (now <= detail->flush_time)
+		/* ensure it isn't immediately treated as expired */
+		now = detail->flush_time + 1;
 	head->expiry_time = expiry;
-	head->last_refresh = seconds_since_boot();
+	head->last_refresh = now;
 	smp_wmb(); /* paired with smp_rmb() in cache_is_valid() */
 	set_bit(CACHE_VALID, &head->flags);
 }
@@ -143,7 +148,6 @@ struct cache_head *sunrpc_cache_update(struct cache_detail *detail,
 	 * If 'old' is not VALID, we update it directly,
 	 * otherwise we need to replace it
 	 */
-	struct cache_head **head;
 	struct cache_head *tmp;
 
 	if (!test_bit(CACHE_VALID, &old->flags)) {
@@ -153,7 +157,7 @@ struct cache_head *sunrpc_cache_update(struct cache_detail *detail,
 				set_bit(CACHE_NEGATIVE, &old->flags);
 			else
 				detail->update(old, new);
-			cache_fresh_locked(old, new->expiry_time);
+			cache_fresh_locked(old, new->expiry_time, detail);
 			write_unlock(&detail->hash_lock);
 			cache_fresh_unlocked(old, detail);
 			return old;
@@ -166,21 +170,19 @@ struct cache_head *sunrpc_cache_update(struct cache_detail *detail,
 		cache_put(old, detail);
 		return NULL;
 	}
-	cache_init(tmp);
+	cache_init(tmp, detail);
 	detail->init(tmp, old);
-	head = &detail->hash_table[hash];
 
 	write_lock(&detail->hash_lock);
 	if (test_bit(CACHE_NEGATIVE, &new->flags))
 		set_bit(CACHE_NEGATIVE, &tmp->flags);
 	else
 		detail->update(tmp, new);
-	tmp->next = *head;
-	*head = tmp;
+	hlist_add_head(&tmp->cache_list, &detail->hash_table[hash]);
 	detail->entries++;
 	cache_get(tmp);
-	cache_fresh_locked(tmp, new->expiry_time);
-	cache_fresh_locked(old, 0);
+	cache_fresh_locked(tmp, new->expiry_time, detail);
+	cache_fresh_locked(old, 0, detail);
 	write_unlock(&detail->hash_lock);
 	cache_fresh_unlocked(tmp, detail);
 	cache_fresh_unlocked(old, detail);
@@ -225,7 +227,8 @@ static int try_to_negate_entry(struct cache_detail *detail, struct cache_head *h
 	rv = cache_is_valid(h);
 	if (rv == -EAGAIN) {
 		set_bit(CACHE_NEGATIVE, &h->flags);
-		cache_fresh_locked(h, seconds_since_boot()+CACHE_NEW_EXPIRY);
+		cache_fresh_locked(h, seconds_since_boot()+CACHE_NEW_EXPIRY,
+				   detail);
 		rv = -ENOENT;
 	}
 	write_unlock(&detail->hash_lock);
@@ -416,28 +419,29 @@ static int cache_clean(void)
 	/* find a non-empty bucket in the table */
 	while (current_detail &&
 	       current_index < current_detail->hash_size &&
-	       current_detail->hash_table[current_index] == NULL)
+	       hlist_empty(&current_detail->hash_table[current_index]))
 		current_index++;
 
 	/* find a cleanable entry in the bucket and clean it, or set to next bucket */
 
 	if (current_detail && current_index < current_detail->hash_size) {
-		struct cache_head *ch, **cp;
+		struct cache_head *ch = NULL;
 		struct cache_detail *d;
+		struct hlist_head *head;
+		struct hlist_node *tmp;
 
 		write_lock(&current_detail->hash_lock);
 
 		/* Ok, now to clean this strand */
 
-		cp = & current_detail->hash_table[current_index];
-		for (ch = *cp ; ch ; cp = & ch->next, ch = *cp) {
+		head = &current_detail->hash_table[current_index];
+		hlist_for_each_entry_safe(ch, tmp, head, cache_list) {
 			if (current_detail->nextcheck > ch->expiry_time)
 				current_detail->nextcheck = ch->expiry_time+1;
 			if (!cache_is_expired(current_detail, ch))
 				continue;
 
-			*cp = ch->next;
-			ch->next = NULL;
+			hlist_del_init(&ch->cache_list);
 			current_detail->entries--;
 			rv = 1;
 			break;
@@ -492,10 +496,13 @@ EXPORT_SYMBOL_GPL(cache_flush);
 
 void cache_purge(struct cache_detail *detail)
 {
-	detail->flush_time = LONG_MAX;
+	time_t now = seconds_since_boot();
+	if (detail->flush_time >= now)
+		now = detail->flush_time + 1;
+	/* 'now' is the maximum value any 'last_refresh' can have */
+	detail->flush_time = now;
 	detail->nextcheck = seconds_since_boot();
 	cache_flush();
-	detail->flush_time = 1;
 }
 EXPORT_SYMBOL_GPL(cache_purge);
 
@@ -1218,7 +1225,7 @@ int qword_get(char **bpp, char *dest, int bufsize)
 	if (bp[0] == '\\' && bp[1] == 'x') {
 		/* HEX STRING */
 		bp += 2;
-		while (len < bufsize) {
+		while (len < bufsize - 1) {
 			int h, l;
 
 			h = hex_to_bin(bp[0]);
@@ -1270,18 +1277,13 @@ EXPORT_SYMBOL_GPL(qword_get);
  * get a header, then pass each real item in the cache
  */
 
-struct handle {
-	struct cache_detail *cd;
-};
-
-static void *c_start(struct seq_file *m, loff_t *pos)
+void *cache_seq_start(struct seq_file *m, loff_t *pos)
 	__acquires(cd->hash_lock)
 {
 	loff_t n = *pos;
 	unsigned int hash, entry;
 	struct cache_head *ch;
-	struct cache_detail *cd = ((struct handle*)m->private)->cd;
-
+	struct cache_detail *cd = m->private;
 
 	read_lock(&cd->hash_lock);
 	if (!n--)
@@ -1289,7 +1291,7 @@ static void *c_start(struct seq_file *m, loff_t *pos)
 	hash = n >> 32;
 	entry = n & ((1LL<<32) - 1);
 
-	for (ch=cd->hash_table[hash]; ch; ch=ch->next)
+	hlist_for_each_entry(ch, &cd->hash_table[hash], cache_list)
 		if (!entry--)
 			return ch;
 	n &= ~((1LL<<32) - 1);
@@ -1297,51 +1299,57 @@ static void *c_start(struct seq_file *m, loff_t *pos)
 		hash++;
 		n += 1LL<<32;
 	} while(hash < cd->hash_size &&
-		cd->hash_table[hash]==NULL);
+		hlist_empty(&cd->hash_table[hash]));
 	if (hash >= cd->hash_size)
 		return NULL;
 	*pos = n+1;
-	return cd->hash_table[hash];
+	return hlist_entry_safe(cd->hash_table[hash].first,
+				struct cache_head, cache_list);
 }
+EXPORT_SYMBOL_GPL(cache_seq_start);
 
-static void *c_next(struct seq_file *m, void *p, loff_t *pos)
+void *cache_seq_next(struct seq_file *m, void *p, loff_t *pos)
 {
 	struct cache_head *ch = p;
 	int hash = (*pos >> 32);
-	struct cache_detail *cd = ((struct handle*)m->private)->cd;
+	struct cache_detail *cd = m->private;
 
 	if (p == SEQ_START_TOKEN)
 		hash = 0;
-	else if (ch->next == NULL) {
+	else if (ch->cache_list.next == NULL) {
 		hash++;
 		*pos += 1LL<<32;
 	} else {
 		++*pos;
-		return ch->next;
+		return hlist_entry_safe(ch->cache_list.next,
+					struct cache_head, cache_list);
 	}
 	*pos &= ~((1LL<<32) - 1);
 	while (hash < cd->hash_size &&
-	       cd->hash_table[hash] == NULL) {
+	       hlist_empty(&cd->hash_table[hash])) {
 		hash++;
 		*pos += 1LL<<32;
 	}
 	if (hash >= cd->hash_size)
 		return NULL;
 	++*pos;
-	return cd->hash_table[hash];
+	return hlist_entry_safe(cd->hash_table[hash].first,
+				struct cache_head, cache_list);
 }
+EXPORT_SYMBOL_GPL(cache_seq_next);
 
-static void c_stop(struct seq_file *m, void *p)
+void cache_seq_stop(struct seq_file *m, void *p)
 	__releases(cd->hash_lock)
 {
-	struct cache_detail *cd = ((struct handle*)m->private)->cd;
+	struct cache_detail *cd = m->private;
 	read_unlock(&cd->hash_lock);
 }
+EXPORT_SYMBOL_GPL(cache_seq_stop);
 
 static int c_show(struct seq_file *m, void *p)
 {
 	struct cache_head *cp = p;
-	struct cache_detail *cd = ((struct handle*)m->private)->cd;
+	struct cache_detail *cd = m->private;
 
 	if (p == SEQ_START_TOKEN)
 		return cd->cache_show(m, cd, NULL);
@@ -1364,33 +1372,36 @@ static int c_show(struct seq_file *m, void *p)
 }
 
 static const struct seq_operations cache_content_op = {
-	.start	= c_start,
-	.next	= c_next,
-	.stop	= c_stop,
+	.start	= cache_seq_start,
+	.next	= cache_seq_next,
+	.stop	= cache_seq_stop,
 	.show	= c_show,
 };
 
 static int content_open(struct inode *inode, struct file *file,
 			struct cache_detail *cd)
 {
-	struct handle *han;
+	struct seq_file *seq;
+	int err;
 
 	if (!cd || !try_module_get(cd->owner))
 		return -EACCES;
-	han = __seq_open_private(file, &cache_content_op, sizeof(*han));
-	if (han == NULL) {
+
+	err = seq_open(file, &cache_content_op);
+	if (err) {
 		module_put(cd->owner);
-		return -ENOMEM;
+		return err;
 	}
 
-	han->cd = cd;
+	seq = file->private_data;
+	seq->private = cd;
 	return 0;
 }
 
 static int content_release(struct inode *inode, struct file *file,
 		struct cache_detail *cd)
 {
-	int ret = seq_release_private(inode, file);
+	int ret = seq_release(inode, file);
 	module_put(cd->owner);
 	return ret;
 }
@@ -1437,6 +1448,7 @@ static ssize_t write_flush(struct file *file, const char __user *buf,
 {
 	char tbuf[20];
 	char *bp, *ep;
+	time_t then, now;
 
 	if (*ppos || count > sizeof(tbuf)-1)
 		return -EINVAL;
@@ -1448,8 +1460,22 @@ static ssize_t write_flush(struct file *file, const char __user *buf,
 		return -EINVAL;
 
 	bp = tbuf;
-	cd->flush_time = get_expiry(&bp);
-	cd->nextcheck = seconds_since_boot();
+	then = get_expiry(&bp);
+	now = seconds_since_boot();
+	cd->nextcheck = now;
+	/* Can only set flush_time to 1 second beyond "now", or
+	 * possibly 1 second beyond flushtime.  This is because
+	 * flush_time never goes backwards so it mustn't get too far
+	 * ahead of time.
+	 */
+	if (then >= now) {
+		/* Want to flush everything, so behave like cache_purge() */
+		if (cd->flush_time >= now)
+			now = cd->flush_time + 1;
+		then = now;
+	}
+
+	cd->flush_time = then;
 	cache_flush();
 
 	*ppos += count;
@@ -1665,17 +1691,21 @@ EXPORT_SYMBOL_GPL(cache_unregister_net);
 struct cache_detail *cache_create_net(struct cache_detail *tmpl, struct net *net)
 {
 	struct cache_detail *cd;
+	int i;
 
 	cd = kmemdup(tmpl, sizeof(struct cache_detail), GFP_KERNEL);
 	if (cd == NULL)
 		return ERR_PTR(-ENOMEM);
 
-	cd->hash_table = kzalloc(cd->hash_size * sizeof(struct cache_head *),
+	cd->hash_table = kzalloc(cd->hash_size * sizeof(struct hlist_head),
 				 GFP_KERNEL);
 	if (cd->hash_table == NULL) {
 		kfree(cd);
 		return ERR_PTR(-ENOMEM);
 	}
+
+	for (i = 0; i < cd->hash_size; i++)
+		INIT_HLIST_HEAD(&cd->hash_table[i]);
 	cd->net = net;
 	return cd;
 }
diff --git a/kernel/net/sunrpc/clnt.c b/kernel/net/sunrpc/clnt.c
index e6ce15173..23608eb0d 100644
--- a/kernel/net/sunrpc/clnt.c
+++ b/kernel/net/sunrpc/clnt.c
@@ -891,15 +891,8 @@ void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
 			task->tk_flags |= RPC_TASK_SOFT;
 		if (clnt->cl_noretranstimeo)
 			task->tk_flags |= RPC_TASK_NO_RETRANS_TIMEOUT;
-		if (sk_memalloc_socks()) {
-			struct rpc_xprt *xprt;
-
-			rcu_read_lock();
-			xprt = rcu_dereference(clnt->cl_xprt);
-			if (xprt->swapper)
-				task->tk_flags |= RPC_TASK_SWAPPER;
-			rcu_read_unlock();
-		}
+		if (atomic_read(&clnt->cl_swapper))
+			task->tk_flags |= RPC_TASK_SWAPPER;
 		/* Add to the client's list of all tasks */
 		spin_lock(&clnt->cl_lock);
 		list_add_tail(&task->tk_task, &clnt->cl_tasks);
@@ -1031,15 +1024,14 @@ EXPORT_SYMBOL_GPL(rpc_call_async);
  * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
  * rpc_execute against it
  * @req: RPC request
- * @tk_ops: RPC call ops
  */
-struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
-				const struct rpc_call_ops *tk_ops)
+struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req)
 {
 	struct rpc_task *task;
 	struct xdr_buf *xbufp = &req->rq_snd_buf;
 	struct rpc_task_setup task_setup_data = {
-		.callback_ops = tk_ops,
+		.callback_ops = &rpc_default_ops,
+		.flags = RPC_TASK_SOFTCONN,
 	};
 
 	dprintk("RPC: rpc_run_bc_task req= %p\n", req);
@@ -1614,6 +1606,7 @@ call_allocate(struct rpc_task *task)
 					req->rq_callsize + req->rq_rcvsize);
 	if (req->rq_buffer != NULL)
 		return;
+	xprt_inject_disconnect(xprt);
 
 	dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
 
@@ -1909,6 +1902,7 @@ call_transmit_status(struct rpc_task *task)
 
 	switch (task->tk_status) {
 	case -EAGAIN:
+	case -ENOBUFS:
 		break;
 	default:
 		dprint_status(task);
@@ -1935,7 +1929,6 @@ call_transmit_status(struct rpc_task *task)
 	case -ECONNABORTED:
 	case -EADDRINUSE:
 	case -ENOTCONN:
-	case -ENOBUFS:
 	case -EPIPE:
 		rpc_task_force_reencode(task);
 	}
@@ -1951,33 +1944,36 @@ call_bc_transmit(struct rpc_task *task)
 {
 	struct rpc_rqst *req = task->tk_rqstp;
 
-	if (!xprt_prepare_transmit(task)) {
-		/*
-		 * Could not reserve the transport. Try again after the
-		 * transport is released.
-		 */
-		task->tk_status = 0;
-		task->tk_action = call_bc_transmit;
-		return;
-	}
+	if (!xprt_prepare_transmit(task))
+		goto out_retry;
 
-	task->tk_action = rpc_exit_task;
 	if (task->tk_status < 0) {
 		printk(KERN_NOTICE "RPC: Could not send backchannel reply "
 			"error: %d\n", task->tk_status);
-		return;
+		goto out_done;
 	}
+	if (req->rq_connect_cookie != req->rq_xprt->connect_cookie)
+		req->rq_bytes_sent = 0;
 
 	xprt_transmit(task);
+
+	if (task->tk_status == -EAGAIN)
+		goto out_nospace;
+
 	xprt_end_transmit(task);
 	dprint_status(task);
 	switch (task->tk_status) {
 	case 0:
 		/* Success */
-		break;
 	case -EHOSTDOWN:
 	case -EHOSTUNREACH:
 	case -ENETUNREACH:
+	case -ECONNRESET:
+	case -ECONNREFUSED:
+	case -EADDRINUSE:
+	case -ENOTCONN:
+	case -EPIPE:
+		break;
 	case -ETIMEDOUT:
 		/*
 		 * Problem reaching the server.  Disconnect and let the
@@ -2002,6 +1998,13 @@ call_bc_transmit(struct rpc_task *task)
 		break;
 	}
 	rpc_wake_up_queued_task(&req->rq_xprt->pending, task);
+out_done:
+	task->tk_action = rpc_exit_task;
+	return;
+out_nospace:
+	req->rq_connect_cookie = req->rq_xprt->connect_cookie;
+out_retry:
+	task->tk_status = 0;
 }
 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
 
@@ -2054,12 +2057,13 @@ call_status(struct rpc_task *task)
 	case -ECONNABORTED:
 		rpc_force_rebind(clnt);
 	case -EADDRINUSE:
-	case -ENOBUFS:
 		rpc_delay(task, 3*HZ);
 	case -EPIPE:
 	case -ENOTCONN:
 		task->tk_action = call_bind;
 		break;
+	case -ENOBUFS:
+		rpc_delay(task, HZ>>2);
 	case -EAGAIN:
 		task->tk_action = call_transmit;
 		break;
@@ -2476,3 +2480,59 @@ void rpc_show_tasks(struct net *net)
 	spin_unlock(&sn->rpc_client_lock);
 }
 #endif
+
+#if IS_ENABLED(CONFIG_SUNRPC_SWAP)
+int
+rpc_clnt_swap_activate(struct rpc_clnt *clnt)
+{
+	int ret = 0;
+	struct rpc_xprt	*xprt;
+
+	if (atomic_inc_return(&clnt->cl_swapper) == 1) {
+retry:
+		rcu_read_lock();
+		xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
+		rcu_read_unlock();
+		if (!xprt) {
+			/*
+			 * If we didn't get a reference, then we likely are
+			 * racing with a migration event. Wait for a grace
+			 * period and try again.
+			 */
+			synchronize_rcu();
+			goto retry;
+		}
+
+		ret = xprt_enable_swap(xprt);
+		xprt_put(xprt);
+	}
+	return ret;
+}
+EXPORT_SYMBOL_GPL(rpc_clnt_swap_activate);
+
+void
+rpc_clnt_swap_deactivate(struct rpc_clnt *clnt)
+{
+	struct rpc_xprt	*xprt;
+
+	if (atomic_dec_if_positive(&clnt->cl_swapper) == 0) {
+retry:
+		rcu_read_lock();
+		xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
+		rcu_read_unlock();
+		if (!xprt) {
+			/*
+			 * If we didn't get a reference, then we likely are
+			 * racing with a migration event. Wait for a grace
+			 * period and try again.
+			 */
+			synchronize_rcu();
+			goto retry;
+		}
+
+		xprt_disable_swap(xprt);
+		xprt_put(xprt);
+	}
+}
+EXPORT_SYMBOL_GPL(rpc_clnt_swap_deactivate);
+#endif /* CONFIG_SUNRPC_SWAP */
diff --git a/kernel/net/sunrpc/debugfs.c b/kernel/net/sunrpc/debugfs.c
index 82962f7e6..e7b4d9356 100644
--- a/kernel/net/sunrpc/debugfs.c
+++ b/kernel/net/sunrpc/debugfs.c
@@ -10,9 +10,12 @@
 #include "netns.h"
 
 static struct dentry *topdir;
+static struct dentry *rpc_fault_dir;
 static struct dentry *rpc_clnt_dir;
 static struct dentry *rpc_xprt_dir;
 
+unsigned int rpc_inject_disconnect;
+
 struct rpc_clnt_iter {
 	struct rpc_clnt	*clnt;
 	loff_t		pos;
@@ -257,6 +260,8 @@ rpc_xprt_debugfs_register(struct rpc_xprt *xprt)
 		debugfs_remove_recursive(xprt->debugfs);
 		xprt->debugfs = NULL;
 	}
+
+	atomic_set(&xprt->inject_disconnect, rpc_inject_disconnect);
 }
 
 void
@@ -266,11 +271,79 @@ rpc_xprt_debugfs_unregister(struct rpc_xprt *xprt)
 	xprt->debugfs = NULL;
 }
 
+static int
+fault_open(struct inode *inode, struct file *filp)
+{
+	filp->private_data = kmalloc(128, GFP_KERNEL);
+	if (!filp->private_data)
+		return -ENOMEM;
+	return 0;
+}
+
+static int
+fault_release(struct inode *inode, struct file *filp)
+{
+	kfree(filp->private_data);
+	return 0;
+}
+
+static ssize_t
+fault_disconnect_read(struct file *filp, char __user *user_buf,
+		      size_t len, loff_t *offset)
+{
+	char *buffer = (char *)filp->private_data;
+	size_t size;
+
+	size = sprintf(buffer, "%u\n", rpc_inject_disconnect);
+	return simple_read_from_buffer(user_buf, len, offset, buffer, size);
+}
+
+static ssize_t
+fault_disconnect_write(struct file *filp, const char __user *user_buf,
+		       size_t len, loff_t *offset)
+{
+	char buffer[16];
+
+	if (len >= sizeof(buffer))
+		len = sizeof(buffer) - 1;
+	if (copy_from_user(buffer, user_buf, len))
+		return -EFAULT;
+	buffer[len] = '\0';
+	if (kstrtouint(buffer, 10, &rpc_inject_disconnect))
+		return -EINVAL;
+	return len;
+}
+
+static const struct file_operations fault_disconnect_fops = {
+	.owner		= THIS_MODULE,
+	.open		= fault_open,
+	.read		= fault_disconnect_read,
+	.write		= fault_disconnect_write,
+	.release	= fault_release,
+};
+
+static struct dentry *
+inject_fault_dir(struct dentry *topdir)
+{
+	struct dentry *faultdir;
+
+	faultdir = debugfs_create_dir("inject_fault", topdir);
+	if (!faultdir)
+		return NULL;
+
+	if (!debugfs_create_file("disconnect", S_IFREG | S_IRUSR, faultdir,
+				 NULL, &fault_disconnect_fops))
+		return NULL;
+
+	return faultdir;
+}
+
 void __exit
 sunrpc_debugfs_exit(void)
 {
 	debugfs_remove_recursive(topdir);
 	topdir = NULL;
+	rpc_fault_dir = NULL;
 	rpc_clnt_dir = NULL;
 	rpc_xprt_dir = NULL;
 }
@@ -282,6 +355,10 @@ sunrpc_debugfs_init(void)
 	if (!topdir)
 		return;
 
+	rpc_fault_dir = inject_fault_dir(topdir);
+	if (!rpc_fault_dir)
+		goto out_remove;
+
 	rpc_clnt_dir = debugfs_create_dir("rpc_clnt", topdir);
 	if (!rpc_clnt_dir)
 		goto out_remove;
@@ -294,5 +371,6 @@ sunrpc_debugfs_init(void)
 out_remove:
 	debugfs_remove_recursive(topdir);
 	topdir = NULL;
+	rpc_fault_dir = NULL;
 	rpc_clnt_dir = NULL;
 }
diff --git a/kernel/net/sunrpc/sched.c b/kernel/net/sunrpc/sched.c
index 337ca851a..73ad57a59 100644
--- a/kernel/net/sunrpc/sched.c
+++ b/kernel/net/sunrpc/sched.c
@@ -250,11 +250,11 @@ void rpc_destroy_wait_queue(struct rpc_wait_queue *queue)
 }
 EXPORT_SYMBOL_GPL(rpc_destroy_wait_queue);
 
-static int rpc_wait_bit_killable(struct wait_bit_key *key)
+static int rpc_wait_bit_killable(struct wait_bit_key *key, int mode)
 {
-	if (fatal_signal_pending(current))
-		return -ERESTARTSYS;
 	freezable_schedule_unsafe();
+	if (signal_pending_state(mode, current))
+		return -ERESTARTSYS;
 	return 0;
 }
 
@@ -1092,14 +1092,10 @@ void
 rpc_destroy_mempool(void)
 {
 	rpciod_stop();
-	if (rpc_buffer_mempool)
-		mempool_destroy(rpc_buffer_mempool);
-	if (rpc_task_mempool)
-		mempool_destroy(rpc_task_mempool);
-	if (rpc_task_slabp)
-		kmem_cache_destroy(rpc_task_slabp);
-	if (rpc_buffer_slabp)
-		kmem_cache_destroy(rpc_buffer_slabp);
+	mempool_destroy(rpc_buffer_mempool);
+	mempool_destroy(rpc_task_mempool);
+	kmem_cache_destroy(rpc_task_slabp);
+	kmem_cache_destroy(rpc_buffer_slabp);
 	rpc_destroy_wait_queue(&delay_queue);
 }
 
diff --git a/kernel/net/sunrpc/svc.c b/kernel/net/sunrpc/svc.c
index 78974e4d9..cc9852897 100644
--- a/kernel/net/sunrpc/svc.c
+++ b/kernel/net/sunrpc/svc.c
@@ -34,36 +34,19 @@
 
 static void svc_unregister(const struct svc_serv *serv, struct net *net);
 
-#define svc_serv_is_pooled(serv)    ((serv)->sv_function)
+#define svc_serv_is_pooled(serv)    ((serv)->sv_ops->svo_function)
 
-/*
- * Mode for mapping cpus to pools.
- */
-enum {
-	SVC_POOL_AUTO = -1,	/* choose one of the others */
-	SVC_POOL_GLOBAL,	/* no mapping, just a single global pool
-				 * (legacy & UP mode) */
-	SVC_POOL_PERCPU,	/* one pool per cpu */
-	SVC_POOL_PERNODE	/* one pool per numa node */
-};
 #define SVC_POOL_DEFAULT	SVC_POOL_GLOBAL
 
 /*
  * Structure for mapping cpus to pools and vice versa.
  * Setup once during sunrpc initialisation.
  */
-static struct svc_pool_map {
-	int count;			/* How many svc_servs use us */
-	int mode;			/* Note: int not enum to avoid
-					 * warnings about "enumeration value
-					 * not handled in switch" */
-	unsigned int npools;
-	unsigned int *pool_to;		/* maps pool id to cpu or node */
-	unsigned int *to_pool;		/* maps cpu or node to pool id */
-} svc_pool_map = {
-	.count = 0,
+struct svc_pool_map svc_pool_map = {
 	.mode = SVC_POOL_DEFAULT
 };
+EXPORT_SYMBOL_GPL(svc_pool_map);
+
 static DEFINE_MUTEX(svc_pool_map_mutex);/* protects svc_pool_map.count only */
 
 static int
@@ -236,7 +219,7 @@ svc_pool_map_init_pernode(struct svc_pool_map *m)
  * vice versa).  Initialise the map if we're the first user.
  * Returns the number of pools.
  */
-static unsigned int
+unsigned int
 svc_pool_map_get(void)
 {
 	struct svc_pool_map *m = &svc_pool_map;
@@ -271,7 +254,7 @@ svc_pool_map_get(void)
 	mutex_unlock(&svc_pool_map_mutex);
 	return m->npools;
 }
-
+EXPORT_SYMBOL_GPL(svc_pool_map_get);
 
 /*
  * Drop a reference to the global map of cpus to pools.
@@ -280,7 +263,7 @@ svc_pool_map_get(void)
  * mode using the pool_mode module option without
  * rebooting or re-loading sunrpc.ko.
  */
-static void
+void
 svc_pool_map_put(void)
 {
 	struct svc_pool_map *m = &svc_pool_map;
@@ -297,7 +280,7 @@ svc_pool_map_put(void)
 
 	mutex_unlock(&svc_pool_map_mutex);
 }
-
+EXPORT_SYMBOL_GPL(svc_pool_map_put);
 
 static int svc_pool_map_get_node(unsigned int pidx)
 {
@@ -423,7 +406,7 @@ EXPORT_SYMBOL_GPL(svc_bind);
  */
 static struct svc_serv *
 __svc_create(struct svc_program *prog, unsigned int bufsize, int npools,
-	     void (*shutdown)(struct svc_serv *serv, struct net *net))
+	     struct svc_serv_ops *ops)
 {
 	struct svc_serv	*serv;
 	unsigned int vers;
@@ -440,7 +423,7 @@ __svc_create(struct svc_program *prog, unsigned int bufsize, int npools,
 		bufsize = RPCSVC_MAXPAYLOAD;
 	serv->sv_max_payload = bufsize? bufsize : 4096;
 	serv->sv_max_mesg  = roundup(serv->sv_max_payload + PAGE_SIZE, PAGE_SIZE);
-	serv->sv_shutdown  = shutdown;
+	serv->sv_ops = ops;
 	xdrsize = 0;
 	while (prog) {
 		prog->pg_lovers = prog->pg_nvers-1;
@@ -486,26 +469,22 @@ __svc_create(struct svc_program *prog, unsigned int bufsize, int npools,
 
 struct svc_serv *
 svc_create(struct svc_program *prog, unsigned int bufsize,
-	   void (*shutdown)(struct svc_serv *serv, struct net *net))
+	   struct svc_serv_ops *ops)
 {
-	return __svc_create(prog, bufsize, /*npools*/1, shutdown);
+	return __svc_create(prog, bufsize, /*npools*/1, ops);
 }
 EXPORT_SYMBOL_GPL(svc_create);
 
 struct svc_serv *
 svc_create_pooled(struct svc_program *prog, unsigned int bufsize,
-		  void (*shutdown)(struct svc_serv *serv, struct net *net),
-		  svc_thread_fn func, struct module *mod)
+		  struct svc_serv_ops *ops)
 {
 	struct svc_serv *serv;
 	unsigned int npools = svc_pool_map_get();
 
-	serv = __svc_create(prog, bufsize, npools, shutdown);
+	serv = __svc_create(prog, bufsize, npools, ops);
 	if (!serv)
 		goto out_err;
-
-	serv->sv_function = func;
-	serv->sv_module = mod;
 	return serv;
 out_err:
 	svc_pool_map_put();
@@ -517,8 +496,8 @@ void svc_shutdown_net(struct svc_serv *serv, struct net *net)
 {
 	svc_close_net(serv, net);
 
-	if (serv->sv_shutdown)
-		serv->sv_shutdown(serv, net);
+	if (serv->sv_ops->svo_shutdown)
+		serv->sv_ops->svo_shutdown(serv, net);
 }
 EXPORT_SYMBOL_GPL(svc_shutdown_net);
 
@@ -604,40 +583,52 @@ svc_release_buffer(struct svc_rqst *rqstp)
 }
 
 struct svc_rqst *
-svc_prepare_thread(struct svc_serv *serv, struct svc_pool *pool, int node)
+svc_rqst_alloc(struct svc_serv *serv, struct svc_pool *pool, int node)
 {
 	struct svc_rqst	*rqstp;
 
 	rqstp = kzalloc_node(sizeof(*rqstp), GFP_KERNEL, node);
 	if (!rqstp)
-		goto out_enomem;
+		return rqstp;
 
-	serv->sv_nrthreads++;
 	__set_bit(RQ_BUSY, &rqstp->rq_flags);
 	spin_lock_init(&rqstp->rq_lock);
 	rqstp->rq_server = serv;
 	rqstp->rq_pool = pool;
-	spin_lock_bh(&pool->sp_lock);
-	pool->sp_nrthreads++;
-	list_add_rcu(&rqstp->rq_all, &pool->sp_all_threads);
-	spin_unlock_bh(&pool->sp_lock);
 
 	rqstp->rq_argp = kmalloc_node(serv->sv_xdrsize, GFP_KERNEL, node);
 	if (!rqstp->rq_argp)
-		goto out_thread;
+		goto out_enomem;
 
 	rqstp->rq_resp = kmalloc_node(serv->sv_xdrsize, GFP_KERNEL, node);
 	if (!rqstp->rq_resp)
-		goto out_thread;
+		goto out_enomem;
 
 	if (!svc_init_buffer(rqstp, serv->sv_max_mesg, node))
-		goto out_thread;
+		goto out_enomem;
 
 	return rqstp;
-out_thread:
-	svc_exit_thread(rqstp);
 out_enomem:
-	return ERR_PTR(-ENOMEM);
+	svc_rqst_free(rqstp);
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(svc_rqst_alloc);
+
+struct svc_rqst *
+svc_prepare_thread(struct svc_serv *serv, struct svc_pool *pool, int node)
+{
+	struct svc_rqst	*rqstp;
+
+	rqstp = svc_rqst_alloc(serv, pool, node);
+	if (!rqstp)
+		return ERR_PTR(-ENOMEM);
+
+	serv->sv_nrthreads++;
+	spin_lock_bh(&pool->sp_lock);
+	pool->sp_nrthreads++;
+	list_add_rcu(&rqstp->rq_all, &pool->sp_all_threads);
+	spin_unlock_bh(&pool->sp_lock);
+	return rqstp;
 }
 EXPORT_SYMBOL_GPL(svc_prepare_thread);
 
@@ -739,12 +730,12 @@ svc_set_num_threads(struct svc_serv *serv, struct svc_pool *pool, int nrservs)
 			break;
 		}
 
-		__module_get(serv->sv_module);
-		task = kthread_create_on_node(serv->sv_function, rqstp,
+		__module_get(serv->sv_ops->svo_module);
+		task = kthread_create_on_node(serv->sv_ops->svo_function, rqstp,
 					      node, "%s", serv->sv_name);
 		if (IS_ERR(task)) {
 			error = PTR_ERR(task);
-			module_put(serv->sv_module);
+			module_put(serv->sv_ops->svo_module);
 			svc_exit_thread(rqstp);
 			break;
 		}
@@ -772,15 +763,21 @@ EXPORT_SYMBOL_GPL(svc_set_num_threads);
  * mutex" for the service.
  */
 void
-svc_exit_thread(struct svc_rqst *rqstp)
+svc_rqst_free(struct svc_rqst *rqstp)
 {
-	struct svc_serv	*serv = rqstp->rq_server;
-	struct svc_pool	*pool = rqstp->rq_pool;
-
 	svc_release_buffer(rqstp);
 	kfree(rqstp->rq_resp);
 	kfree(rqstp->rq_argp);
 	kfree(rqstp->rq_auth_data);
+	kfree_rcu(rqstp, rq_rcu_head);
+}
+EXPORT_SYMBOL_GPL(svc_rqst_free);
+
+void
+svc_exit_thread(struct svc_rqst *rqstp)
+{
+	struct svc_serv	*serv = rqstp->rq_server;
+	struct svc_pool	*pool = rqstp->rq_pool;
 
 	spin_lock_bh(&pool->sp_lock);
 	pool->sp_nrthreads--;
@@ -788,7 +785,7 @@ svc_exit_thread(struct svc_rqst *rqstp)
 		list_del_rcu(&rqstp->rq_all);
 	spin_unlock_bh(&pool->sp_lock);
 
-	kfree_rcu(rqstp, rq_rcu_head);
+	svc_rqst_free(rqstp);
 
 	/* Release the server */
 	if (serv)
@@ -1290,7 +1287,6 @@ err_bad:
 	svc_putnl(resv, ntohl(rpc_stat));
 	goto sendit;
 }
-EXPORT_SYMBOL_GPL(svc_process);
 
 /*
  * Process the RPC request.
@@ -1338,6 +1334,7 @@ out_drop:
 	svc_drop(rqstp);
 	return 0;
 }
+EXPORT_SYMBOL_GPL(svc_process);
 
 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 /*
@@ -1350,6 +1347,11 @@ bc_svc_process(struct svc_serv *serv, struct rpc_rqst *req,
 {
 	struct kvec	*argv = &rqstp->rq_arg.head[0];
 	struct kvec	*resv = &rqstp->rq_res.head[0];
+	struct rpc_task *task;
+	int proc_error;
+	int error;
+
+	dprintk("svc: %s(%p)\n", __func__, req);
 
 	/* Build the svc_rqst used by the common processing routine */
 	rqstp->rq_xprt = serv->sv_bc_xprt;
@@ -1362,31 +1364,54 @@ bc_svc_process(struct svc_serv *serv, struct rpc_rqst *req,
 	memcpy(&rqstp->rq_arg, &req->rq_rcv_buf, sizeof(rqstp->rq_arg));
 	memcpy(&rqstp->rq_res, &req->rq_snd_buf, sizeof(rqstp->rq_res));
 
+	/* Adjust the argument buffer length */
+	rqstp->rq_arg.len = req->rq_private_buf.len;
+	if (rqstp->rq_arg.len <= rqstp->rq_arg.head[0].iov_len) {
+		rqstp->rq_arg.head[0].iov_len = rqstp->rq_arg.len;
+		rqstp->rq_arg.page_len = 0;
+	} else if (rqstp->rq_arg.len <= rqstp->rq_arg.head[0].iov_len +
+			rqstp->rq_arg.page_len)
+		rqstp->rq_arg.page_len = rqstp->rq_arg.len -
+			rqstp->rq_arg.head[0].iov_len;
+	else
+		rqstp->rq_arg.len = rqstp->rq_arg.head[0].iov_len +
+			rqstp->rq_arg.page_len;
+
 	/* reset result send buffer "put" position */
 	resv->iov_len = 0;
 
-	if (rqstp->rq_prot != IPPROTO_TCP) {
-		printk(KERN_ERR "No support for Non-TCP transports!\n");
-		BUG();
-	}
-
 	/*
 	 * Skip the next two words because they've already been
-	 * processed in the trasport
+	 * processed in the transport
 	 */
 	svc_getu32(argv);	/* XID */
 	svc_getnl(argv);	/* CALLDIR */
 
-	/* Returns 1 for send, 0 for drop */
-	if (svc_process_common(rqstp, argv, resv)) {
-		memcpy(&req->rq_snd_buf, &rqstp->rq_res,
-						sizeof(req->rq_snd_buf));
-		return bc_send(req);
-	} else {
-		/* drop request */
+	/* Parse and execute the bc call */
+	proc_error = svc_process_common(rqstp, argv, resv);
+
+	atomic_inc(&req->rq_xprt->bc_free_slots);
+	if (!proc_error) {
+		/* Processing error: drop the request */
 		xprt_free_bc_request(req);
 		return 0;
 	}
+
+	/* Finally, send the reply synchronously */
+	memcpy(&req->rq_snd_buf, &rqstp->rq_res, sizeof(req->rq_snd_buf));
+	task = rpc_run_bc_task(req);
+	if (IS_ERR(task)) {
+		error = PTR_ERR(task);
+		goto out;
+	}
+
+	WARN_ON_ONCE(atomic_read(&task->tk_count) != 1);
+	error = task->tk_status;
+	rpc_put_task(task);
+
+out:
+	dprintk("svc: %s(), error=%d\n", __func__, error);
+	return error;
 }
 EXPORT_SYMBOL_GPL(bc_svc_process);
 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
diff --git a/kernel/net/sunrpc/svc_xprt.c b/kernel/net/sunrpc/svc_xprt.c
index ba2313cd4..5b69bb580 100644
--- a/kernel/net/sunrpc/svc_xprt.c
+++ b/kernel/net/sunrpc/svc_xprt.c
@@ -24,7 +24,6 @@ static int svc_deferred_recv(struct svc_rqst *rqstp);
 static struct cache_deferred_req *svc_defer(struct cache_req *req);
 static void svc_age_temp_xprts(unsigned long closure);
 static void svc_delete_xprt(struct svc_xprt *xprt);
-static void svc_xprt_do_enqueue(struct svc_xprt *xprt);
 
 /* apparently the "standard" is that clients close
  * idle connections after 5 minutes, servers after
@@ -225,12 +224,12 @@ static void svc_xprt_received(struct svc_xprt *xprt)
 	}
 
 	/* As soon as we clear busy, the xprt could be closed and
-	 * 'put', so we need a reference to call svc_xprt_do_enqueue with:
+	 * 'put', so we need a reference to call svc_enqueue_xprt with:
 	 */
 	svc_xprt_get(xprt);
 	smp_mb__before_atomic();
 	clear_bit(XPT_BUSY, &xprt->xpt_flags);
-	svc_xprt_do_enqueue(xprt);
+	xprt->xpt_server->sv_ops->svo_enqueue_xprt(xprt);
 	svc_xprt_put(xprt);
 }
 
@@ -320,7 +319,7 @@ static bool svc_xprt_has_something_to_do(struct svc_xprt *xprt)
 	return false;
 }
 
-static void svc_xprt_do_enqueue(struct svc_xprt *xprt)
+void svc_xprt_do_enqueue(struct svc_xprt *xprt)
 {
 	struct svc_pool *pool;
 	struct svc_rqst	*rqstp = NULL;
@@ -402,6 +401,7 @@ redo_search:
 out:
 	trace_svc_xprt_do_enqueue(xprt, rqstp);
 }
+EXPORT_SYMBOL_GPL(svc_xprt_do_enqueue);
 
 /*
  * Queue up a transport with data pending. If there are idle nfsd
@@ -412,7 +412,7 @@ void svc_xprt_enqueue(struct svc_xprt *xprt)
 {
 	if (test_bit(XPT_BUSY, &xprt->xpt_flags))
 		return;
-	svc_xprt_do_enqueue(xprt);
+	xprt->xpt_server->sv_ops->svo_enqueue_xprt(xprt);
 }
 EXPORT_SYMBOL_GPL(svc_xprt_enqueue);
 
diff --git a/kernel/net/sunrpc/svcsock.c b/kernel/net/sunrpc/svcsock.c
index 0c8120229..1413cdcc1 100644
--- a/kernel/net/sunrpc/svcsock.c
+++ b/kernel/net/sunrpc/svcsock.c
@@ -181,7 +181,7 @@ int svc_send_common(struct socket *sock, struct xdr_buf *xdr,
 	struct page	**ppage = xdr->pages;
 	size_t		base = xdr->page_base;
 	unsigned int	pglen = xdr->page_len;
-	unsigned int	flags = MSG_MORE;
+	unsigned int	flags = MSG_MORE | MSG_SENDPAGE_NOTLAST;
 	int		slen;
 	int		len = 0;
 
@@ -399,6 +399,31 @@ static int svc_sock_secure_port(struct svc_rqst *rqstp)
 	return svc_port_is_privileged(svc_addr(rqstp));
 }
 
+static bool sunrpc_waitqueue_active(wait_queue_head_t *wq)
+{
+	if (!wq)
+		return false;
+	/*
+	 * There should normally be a memory * barrier here--see
+	 * wq_has_sleeper().
+	 *
+	 * It appears that isn't currently necessary, though, basically
+	 * because callers all appear to have sufficient memory barriers
+	 * between the time the relevant change is made and the
+	 * time they call these callbacks.
+	 *
+	 * The nfsd code itself doesn't actually explicitly wait on
+	 * these waitqueues, but it may wait on them for example in
+	 * sendpage() or sendmsg() calls.  (And those may be the only
+	 * places, since it it uses nonblocking reads.)
+	 *
+	 * Maybe we should add the memory barriers anyway, but these are
+	 * hot paths so we'd need to be convinced there's no sigificant
+	 * penalty.
+	 */
+	return waitqueue_active(wq);
+}
+
 /*
  * INET callback when data has been received on the socket.
  */
@@ -414,7 +439,7 @@ static void svc_udp_data_ready(struct sock *sk)
 		set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
 		svc_xprt_enqueue(&svsk->sk_xprt);
 	}
-	if (wq && waitqueue_active(wq))
+	if (sunrpc_waitqueue_active(wq))
 		wake_up_interruptible(wq);
 }
 
@@ -432,7 +457,7 @@ static void svc_write_space(struct sock *sk)
 		svc_xprt_enqueue(&svsk->sk_xprt);
 	}
 
-	if (wq && waitqueue_active(wq)) {
+	if (sunrpc_waitqueue_active(wq)) {
 		dprintk("RPC svc_write_space: someone sleeping on %p\n",
 		       svsk);
 		wake_up_interruptible(wq);
@@ -787,7 +812,7 @@ static void svc_tcp_listen_data_ready(struct sock *sk)
 	}
 
 	wq = sk_sleep(sk);
-	if (wq && waitqueue_active(wq))
+	if (sunrpc_waitqueue_active(wq))
 		wake_up_interruptible_all(wq);
 }
 
@@ -808,7 +833,7 @@ static void svc_tcp_state_change(struct sock *sk)
 		set_bit(XPT_CLOSE, &svsk->sk_xprt.xpt_flags);
 		svc_xprt_enqueue(&svsk->sk_xprt);
 	}
-	if (wq && waitqueue_active(wq))
+	if (sunrpc_waitqueue_active(wq))
 		wake_up_interruptible_all(wq);
 }
 
@@ -823,7 +848,7 @@ static void svc_tcp_data_ready(struct sock *sk)
 		set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
 		svc_xprt_enqueue(&svsk->sk_xprt);
 	}
-	if (wq && waitqueue_active(wq))
+	if (sunrpc_waitqueue_active(wq))
 		wake_up_interruptible(wq);
 }
 
@@ -1367,7 +1392,6 @@ EXPORT_SYMBOL_GPL(svc_sock_update_bufs);
 
 /*
  * Initialize socket for RPC use and create svc_sock struct
- * XXX: May want to setsockopt SO_SNDBUF and SO_RCVBUF.
  */
 static struct svc_sock *svc_setup_socket(struct svc_serv *serv,
 						struct socket *sock,
@@ -1594,7 +1618,7 @@ static void svc_sock_detach(struct svc_xprt *xprt)
 	sk->sk_write_space = svsk->sk_owspace;
 
 	wq = sk_sleep(sk);
-	if (wq && waitqueue_active(wq))
+	if (sunrpc_waitqueue_active(wq))
 		wake_up_interruptible(wq);
 }
 
diff --git a/kernel/net/sunrpc/sysctl.c b/kernel/net/sunrpc/sysctl.c
index 887f0183b..c88d9bc06 100644
--- a/kernel/net/sunrpc/sysctl.c
+++ b/kernel/net/sunrpc/sysctl.c
@@ -76,7 +76,7 @@ static int
 proc_dodebug(struct ctl_table *table, int write,
 				void __user *buffer, size_t *lenp, loff_t *ppos)
 {
-	char		tmpbuf[20], c, *s;
+	char		tmpbuf[20], c, *s = NULL;
 	char __user *p;
 	unsigned int	value;
 	size_t		left, len;
@@ -103,23 +103,24 @@ proc_dodebug(struct ctl_table *table, int write,
 			return -EFAULT;
 		tmpbuf[left] = '\0';
 
-		for (s = tmpbuf, value = 0; '0' <= *s && *s <= '9'; s++, left--)
-			value = 10 * value + (*s - '0');
-		if (*s && !isspace(*s))
-			return -EINVAL;
-		while (left && isspace(*s))
-			left--, s++;
+		value = simple_strtol(tmpbuf, &s, 0);
+		if (s) {
+			left -= (s - tmpbuf);
+			if (left && !isspace(*s))
+				return -EINVAL;
+			while (left && isspace(*s))
+				left--, s++;
+		} else
+			left = 0;
 		*(unsigned int *) table->data = value;
 		/* Display the RPC tasks on writing to rpc_debug */
 		if (strcmp(table->procname, "rpc_debug") == 0)
 			rpc_show_tasks(&init_net);
 	} else {
-		if (!access_ok(VERIFY_WRITE, buffer, left))
-			return -EFAULT;
-		len = sprintf(tmpbuf, "%d", *(unsigned int *) table->data);
+		len = sprintf(tmpbuf, "0x%04x", *(unsigned int *) table->data);
 		if (len > left)
 			len = left;
-		if (__copy_to_user(buffer, tmpbuf, len))
+		if (copy_to_user(buffer, tmpbuf, len))
 			return -EFAULT;
 		if ((left -= len) > 0) {
 			if (put_user('\n', (char __user *)buffer + len))
diff --git a/kernel/net/sunrpc/xprt.c b/kernel/net/sunrpc/xprt.c
index d109d308e..2e98f4a24 100644
--- a/kernel/net/sunrpc/xprt.c
+++ b/kernel/net/sunrpc/xprt.c
@@ -68,6 +68,7 @@ static void	 xprt_init(struct rpc_xprt *xprt, struct net *net);
 static void	xprt_request_init(struct rpc_task *, struct rpc_xprt *);
 static void	xprt_connect_status(struct rpc_task *task);
 static int      __xprt_get_cong(struct rpc_xprt *, struct rpc_task *);
+static void     __xprt_put_cong(struct rpc_xprt *, struct rpc_rqst *);
 static void	 xprt_destroy(struct rpc_xprt *xprt);
 
 static DEFINE_SPINLOCK(xprt_list_lock);
@@ -250,6 +251,8 @@ int xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task)
 	}
 	xprt_clear_locked(xprt);
 out_sleep:
+	if (req)
+		__xprt_put_cong(xprt, req);
 	dprintk("RPC: %5u failed to lock transport %p\n", task->tk_pid, xprt);
 	task->tk_timeout = 0;
 	task->tk_status = -EAGAIN;
@@ -608,8 +611,8 @@ static void xprt_autoclose(struct work_struct *work)
 	struct rpc_xprt *xprt =
 		container_of(work, struct rpc_xprt, task_cleanup);
 
-	xprt->ops->close(xprt);
 	clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
+	xprt->ops->close(xprt);
 	xprt_release_write(xprt, NULL);
 	wake_up_bit(&xprt->state, XPRT_LOCKED);
 }
@@ -969,6 +972,7 @@ void xprt_transmit(struct rpc_task *task)
 		task->tk_status = status;
 		return;
 	}
+	xprt_inject_disconnect(xprt);
 
 	dprintk("RPC: %5u xmit complete\n", task->tk_pid);
 	task->tk_flags |= RPC_TASK_SENT;
@@ -1287,6 +1291,7 @@ void xprt_release(struct rpc_task *task)
 	spin_unlock_bh(&xprt->transport_lock);
 	if (req->rq_buffer)
 		xprt->ops->buf_free(req->rq_buffer);
+	xprt_inject_disconnect(xprt);
 	if (req->rq_cred != NULL)
 		put_rpccred(req->rq_cred);
 	task->tk_rqstp = NULL;
diff --git a/kernel/net/sunrpc/xprtrdma/Makefile b/kernel/net/sunrpc/xprtrdma/Makefile
index 579f72bbc..33f99d300 100644
--- a/kernel/net/sunrpc/xprtrdma/Makefile
+++ b/kernel/net/sunrpc/xprtrdma/Makefile
@@ -1,9 +1,8 @@
-obj-$(CONFIG_SUNRPC_XPRT_RDMA_CLIENT) += xprtrdma.o
+obj-$(CONFIG_SUNRPC_XPRT_RDMA) += rpcrdma.o
 
-xprtrdma-y := transport.o rpc_rdma.o verbs.o \
-	fmr_ops.o frwr_ops.o physical_ops.o
-
-obj-$(CONFIG_SUNRPC_XPRT_RDMA_SERVER) += svcrdma.o
-
-svcrdma-y := svc_rdma.o svc_rdma_transport.o \
-	svc_rdma_marshal.o svc_rdma_sendto.o svc_rdma_recvfrom.o
+rpcrdma-y := transport.o rpc_rdma.o verbs.o \
+	fmr_ops.o frwr_ops.o physical_ops.o \
+	svc_rdma.o svc_rdma_transport.o \
+	svc_rdma_marshal.o svc_rdma_sendto.o svc_rdma_recvfrom.o \
+	module.o
+rpcrdma-$(CONFIG_SUNRPC_BACKCHANNEL) += backchannel.o
diff --git a/kernel/net/sunrpc/xprtrdma/backchannel.c b/kernel/net/sunrpc/xprtrdma/backchannel.c
new file mode 100644
index 000000000..2dcb44f69
--- /dev/null
+++ b/kernel/net/sunrpc/xprtrdma/backchannel.c
@@ -0,0 +1,394 @@
+/*
+ * Copyright (c) 2015 Oracle.  All rights reserved.
+ *
+ * Support for backward direction RPCs on RPC/RDMA.
+ */
+
+#include <linux/module.h>
+#include <linux/sunrpc/xprt.h>
+#include <linux/sunrpc/svc.h>
+#include <linux/sunrpc/svc_xprt.h>
+
+#include "xprt_rdma.h"
+
+#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
+# define RPCDBG_FACILITY	RPCDBG_TRANS
+#endif
+
+#define RPCRDMA_BACKCHANNEL_DEBUG
+
+static void rpcrdma_bc_free_rqst(struct rpcrdma_xprt *r_xprt,
+				 struct rpc_rqst *rqst)
+{
+	struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
+	struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
+
+	spin_lock(&buf->rb_reqslock);
+	list_del(&req->rl_all);
+	spin_unlock(&buf->rb_reqslock);
+
+	rpcrdma_destroy_req(&r_xprt->rx_ia, req);
+
+	kfree(rqst);
+}
+
+static int rpcrdma_bc_setup_rqst(struct rpcrdma_xprt *r_xprt,
+				 struct rpc_rqst *rqst)
+{
+	struct rpcrdma_ia *ia = &r_xprt->rx_ia;
+	struct rpcrdma_regbuf *rb;
+	struct rpcrdma_req *req;
+	struct xdr_buf *buf;
+	size_t size;
+
+	req = rpcrdma_create_req(r_xprt);
+	if (!req)
+		return -ENOMEM;
+	req->rl_backchannel = true;
+
+	size = RPCRDMA_INLINE_WRITE_THRESHOLD(rqst);
+	rb = rpcrdma_alloc_regbuf(ia, size, GFP_KERNEL);
+	if (IS_ERR(rb))
+		goto out_fail;
+	req->rl_rdmabuf = rb;
+
+	size += RPCRDMA_INLINE_READ_THRESHOLD(rqst);
+	rb = rpcrdma_alloc_regbuf(ia, size, GFP_KERNEL);
+	if (IS_ERR(rb))
+		goto out_fail;
+	rb->rg_owner = req;
+	req->rl_sendbuf = rb;
+	/* so that rpcr_to_rdmar works when receiving a request */
+	rqst->rq_buffer = (void *)req->rl_sendbuf->rg_base;
+
+	buf = &rqst->rq_snd_buf;
+	buf->head[0].iov_base = rqst->rq_buffer;
+	buf->head[0].iov_len = 0;
+	buf->tail[0].iov_base = NULL;
+	buf->tail[0].iov_len = 0;
+	buf->page_len = 0;
+	buf->len = 0;
+	buf->buflen = size;
+
+	return 0;
+
+out_fail:
+	rpcrdma_bc_free_rqst(r_xprt, rqst);
+	return -ENOMEM;
+}
+
+/* Allocate and add receive buffers to the rpcrdma_buffer's
+ * existing list of rep's. These are released when the
+ * transport is destroyed.
+ */
+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--) {
+		rep = rpcrdma_create_rep(r_xprt);
+		if (IS_ERR(rep)) {
+			pr_err("RPC:       %s: reply buffer alloc failed\n",
+			       __func__);
+			rc = PTR_ERR(rep);
+			break;
+		}
+
+		spin_lock_irqsave(&buffers->rb_lock, flags);
+		list_add(&rep->rr_list, &buffers->rb_recv_bufs);
+		spin_unlock_irqrestore(&buffers->rb_lock, flags);
+	}
+
+	return rc;
+}
+
+/**
+ * xprt_rdma_bc_setup - Pre-allocate resources for handling backchannel requests
+ * @xprt: transport associated with these backchannel resources
+ * @reqs: number of concurrent incoming requests to expect
+ *
+ * Returns 0 on success; otherwise a negative errno
+ */
+int xprt_rdma_bc_setup(struct rpc_xprt *xprt, unsigned int reqs)
+{
+	struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
+	struct rpcrdma_buffer *buffer = &r_xprt->rx_buf;
+	struct rpc_rqst *rqst;
+	unsigned int i;
+	int rc;
+
+	/* The backchannel reply path returns each rpc_rqst to the
+	 * bc_pa_list _after_ the reply is sent. If the server is
+	 * faster than the client, it can send another backward
+	 * direction request before the rpc_rqst is returned to the
+	 * list. The client rejects the request in this case.
+	 *
+	 * Twice as many rpc_rqsts are prepared to ensure there is
+	 * always an rpc_rqst available as soon as a reply is sent.
+	 */
+	if (reqs > RPCRDMA_BACKWARD_WRS >> 1)
+		goto out_err;
+
+	for (i = 0; i < (reqs << 1); i++) {
+		rqst = kzalloc(sizeof(*rqst), GFP_KERNEL);
+		if (!rqst) {
+			pr_err("RPC:       %s: Failed to create bc rpc_rqst\n",
+			       __func__);
+			goto out_free;
+		}
+
+		rqst->rq_xprt = &r_xprt->rx_xprt;
+		INIT_LIST_HEAD(&rqst->rq_list);
+		INIT_LIST_HEAD(&rqst->rq_bc_list);
+
+		if (rpcrdma_bc_setup_rqst(r_xprt, rqst))
+			goto out_free;
+
+		spin_lock_bh(&xprt->bc_pa_lock);
+		list_add(&rqst->rq_bc_pa_list, &xprt->bc_pa_list);
+		spin_unlock_bh(&xprt->bc_pa_lock);
+	}
+
+	rc = rpcrdma_bc_setup_reps(r_xprt, reqs);
+	if (rc)
+		goto out_free;
+
+	rc = rpcrdma_ep_post_extra_recv(r_xprt, reqs);
+	if (rc)
+		goto out_free;
+
+	buffer->rb_bc_srv_max_requests = reqs;
+	request_module("svcrdma");
+
+	return 0;
+
+out_free:
+	xprt_rdma_bc_destroy(xprt, reqs);
+
+out_err:
+	pr_err("RPC:       %s: setup backchannel transport failed\n", __func__);
+	return -ENOMEM;
+}
+
+/**
+ * xprt_rdma_bc_up - Create transport endpoint for backchannel service
+ * @serv: server endpoint
+ * @net: network namespace
+ *
+ * The "xprt" is an implied argument: it supplies the name of the
+ * backchannel transport class.
+ *
+ * Returns zero on success, negative errno on failure
+ */
+int xprt_rdma_bc_up(struct svc_serv *serv, struct net *net)
+{
+	int ret;
+
+	ret = svc_create_xprt(serv, "rdma-bc", net, PF_INET, 0, 0);
+	if (ret < 0)
+		return ret;
+	return 0;
+}
+
+/**
+ * rpcrdma_bc_marshal_reply - Send backwards direction reply
+ * @rqst: buffer containing RPC reply data
+ *
+ * Returns zero on success.
+ */
+int rpcrdma_bc_marshal_reply(struct rpc_rqst *rqst)
+{
+	struct rpc_xprt *xprt = rqst->rq_xprt;
+	struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
+	struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
+	struct rpcrdma_msg *headerp;
+	size_t rpclen;
+
+	headerp = rdmab_to_msg(req->rl_rdmabuf);
+	headerp->rm_xid = rqst->rq_xid;
+	headerp->rm_vers = rpcrdma_version;
+	headerp->rm_credit =
+			cpu_to_be32(r_xprt->rx_buf.rb_bc_srv_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;
+
+	rpclen = rqst->rq_svec[0].iov_len;
+
+	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);
+
+	req->rl_send_iov[0].addr = rdmab_addr(req->rl_rdmabuf);
+	req->rl_send_iov[0].length = RPCRDMA_HDRLEN_MIN;
+	req->rl_send_iov[0].lkey = rdmab_lkey(req->rl_rdmabuf);
+
+	req->rl_send_iov[1].addr = rdmab_addr(req->rl_sendbuf);
+	req->rl_send_iov[1].length = rpclen;
+	req->rl_send_iov[1].lkey = rdmab_lkey(req->rl_sendbuf);
+
+	req->rl_niovs = 2;
+	return 0;
+}
+
+/**
+ * xprt_rdma_bc_destroy - Release resources for handling backchannel requests
+ * @xprt: transport associated with these backchannel resources
+ * @reqs: number of incoming requests to destroy; ignored
+ */
+void xprt_rdma_bc_destroy(struct rpc_xprt *xprt, unsigned int reqs)
+{
+	struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
+	struct rpc_rqst *rqst, *tmp;
+
+	spin_lock_bh(&xprt->bc_pa_lock);
+	list_for_each_entry_safe(rqst, tmp, &xprt->bc_pa_list, rq_bc_pa_list) {
+		list_del(&rqst->rq_bc_pa_list);
+		spin_unlock_bh(&xprt->bc_pa_lock);
+
+		rpcrdma_bc_free_rqst(r_xprt, rqst);
+
+		spin_lock_bh(&xprt->bc_pa_lock);
+	}
+	spin_unlock_bh(&xprt->bc_pa_lock);
+}
+
+/**
+ * xprt_rdma_bc_free_rqst - Release a backchannel rqst
+ * @rqst: request to release
+ */
+void xprt_rdma_bc_free_rqst(struct rpc_rqst *rqst)
+{
+	struct rpc_xprt *xprt = rqst->rq_xprt;
+
+	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);
+	smp_mb__after_atomic();
+
+	spin_lock_bh(&xprt->bc_pa_lock);
+	list_add_tail(&rqst->rq_bc_pa_list, &xprt->bc_pa_list);
+	spin_unlock_bh(&xprt->bc_pa_lock);
+}
+
+/**
+ * rpcrdma_bc_receive_call - Handle a backward direction call
+ * @xprt: transport receiving the call
+ * @rep: receive buffer containing the call
+ *
+ * Called in the RPC reply handler, which runs in a tasklet.
+ * Be quick about it.
+ *
+ * Operational assumptions:
+ *    o Backchannel credits are ignored, just as the NFS server
+ *      forechannel currently does
+ *    o The ULP manages a replay cache (eg, NFSv4.1 sessions).
+ *      No replay detection is done at the transport level
+ */
+void rpcrdma_bc_receive_call(struct rpcrdma_xprt *r_xprt,
+			     struct rpcrdma_rep *rep)
+{
+	struct rpc_xprt *xprt = &r_xprt->rx_xprt;
+	struct rpcrdma_msg *headerp;
+	struct svc_serv *bc_serv;
+	struct rpcrdma_req *req;
+	struct rpc_rqst *rqst;
+	struct xdr_buf *buf;
+	size_t size;
+	__be32 *p;
+
+	headerp = rdmab_to_msg(rep->rr_rdmabuf);
+#ifdef RPCRDMA_BACKCHANNEL_DEBUG
+	pr_info("RPC:       %s: callback XID %08x, length=%u\n",
+		__func__, be32_to_cpu(headerp->rm_xid), rep->rr_len);
+	pr_info("RPC:       %s: %*ph\n", __func__, rep->rr_len, headerp);
+#endif
+
+	/* Sanity check:
+	 * Need at least enough bytes for RPC/RDMA header, as code
+	 * here references the header fields by array offset. Also,
+	 * backward calls are always inline, so ensure there
+	 * are some bytes beyond the RPC/RDMA header.
+	 */
+	if (rep->rr_len < RPCRDMA_HDRLEN_MIN + 24)
+		goto out_short;
+	p = (__be32 *)((unsigned char *)headerp + RPCRDMA_HDRLEN_MIN);
+	size = rep->rr_len - RPCRDMA_HDRLEN_MIN;
+
+	/* Grab a free bc rqst */
+	spin_lock(&xprt->bc_pa_lock);
+	if (list_empty(&xprt->bc_pa_list)) {
+		spin_unlock(&xprt->bc_pa_lock);
+		goto out_overflow;
+	}
+	rqst = list_first_entry(&xprt->bc_pa_list,
+				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
+
+	/* Prepare rqst */
+	rqst->rq_reply_bytes_recvd = 0;
+	rqst->rq_bytes_sent = 0;
+	rqst->rq_xid = headerp->rm_xid;
+	set_bit(RPC_BC_PA_IN_USE, &rqst->rq_bc_pa_state);
+
+	buf = &rqst->rq_rcv_buf;
+	memset(buf, 0, sizeof(*buf));
+	buf->head[0].iov_base = p;
+	buf->head[0].iov_len = size;
+	buf->len = size;
+
+	/* The receive buffer has to be hooked to the rpcrdma_req
+	 * so that it can be reposted after the server is done
+	 * parsing it but just before sending the backward
+	 * direction reply.
+	 */
+	req = rpcr_to_rdmar(rqst);
+#ifdef RPCRDMA_BACKCHANNEL_DEBUG
+	pr_info("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 */
+	req->rl_connect_cookie = 0;
+
+	/* Queue rqst for ULP's callback service */
+	bc_serv = xprt->bc_serv;
+	spin_lock(&bc_serv->sv_cb_lock);
+	list_add(&rqst->rq_bc_list, &bc_serv->sv_cb_list);
+	spin_unlock(&bc_serv->sv_cb_lock);
+
+	wake_up(&bc_serv->sv_cb_waitq);
+
+	r_xprt->rx_stats.bcall_count++;
+	return;
+
+out_overflow:
+	pr_warn("RPC/RDMA backchannel overflow\n");
+	xprt_disconnect_done(xprt);
+	/* This receive buffer gets reposted automatically
+	 * when the connection is re-established.
+	 */
+	return;
+
+out_short:
+	pr_warn("RPC/RDMA short backward direction call\n");
+
+	if (rpcrdma_ep_post_recv(&r_xprt->rx_ia, &r_xprt->rx_ep, rep))
+		xprt_disconnect_done(xprt);
+	else
+		pr_warn("RPC:       %s: reposting rep %p\n",
+			__func__, rep);
+}
diff --git a/kernel/net/sunrpc/xprtrdma/fmr_ops.c b/kernel/net/sunrpc/xprtrdma/fmr_ops.c
index 302d4ebf6..f1e8dafbd 100644
--- a/kernel/net/sunrpc/xprtrdma/fmr_ops.c
+++ b/kernel/net/sunrpc/xprtrdma/fmr_ops.c
@@ -11,6 +11,21 @@
  * can take tens of usecs to complete.
  */
 
+/* Normal operation
+ *
+ * A Memory Region is prepared for RDMA READ or WRITE using the
+ * ib_map_phys_fmr verb (fmr_op_map). When the RDMA operation is
+ * finished, the Memory Region is unmapped using the ib_unmap_fmr
+ * verb (fmr_op_unmap).
+ */
+
+/* Transport recovery
+ *
+ * After a transport reconnect, fmr_op_map re-uses the MR already
+ * allocated for the RPC, but generates a fresh rkey then maps the
+ * MR again. This process is synchronous.
+ */
+
 #include "xprt_rdma.h"
 
 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
@@ -50,19 +65,28 @@ fmr_op_init(struct rpcrdma_xprt *r_xprt)
 	struct rpcrdma_mw *r;
 	int i, rc;
 
+	spin_lock_init(&buf->rb_mwlock);
 	INIT_LIST_HEAD(&buf->rb_mws);
 	INIT_LIST_HEAD(&buf->rb_all);
 
-	i = (buf->rb_max_requests + 1) * RPCRDMA_MAX_SEGS;
-	dprintk("RPC:       %s: initializing %d FMRs\n", __func__, i);
+	i = max_t(int, RPCRDMA_MAX_DATA_SEGS / RPCRDMA_MAX_FMR_SGES, 1);
+	i += 2;				/* head + tail */
+	i *= buf->rb_max_requests;	/* one set for each RPC slot */
+	dprintk("RPC:       %s: initalizing %d FMRs\n", __func__, i);
 
+	rc = -ENOMEM;
 	while (i--) {
 		r = kzalloc(sizeof(*r), GFP_KERNEL);
 		if (!r)
-			return -ENOMEM;
+			goto out;
 
-		r->r.fmr = ib_alloc_fmr(pd, mr_access_flags, &fmr_attr);
-		if (IS_ERR(r->r.fmr))
+		r->r.fmr.physaddrs = kmalloc(RPCRDMA_MAX_FMR_SGES *
+					     sizeof(u64), GFP_KERNEL);
+		if (!r->r.fmr.physaddrs)
+			goto out_free;
+
+		r->r.fmr.fmr = ib_alloc_fmr(pd, mr_access_flags, &fmr_attr);
+		if (IS_ERR(r->r.fmr.fmr))
 			goto out_fmr_err;
 
 		list_add(&r->mw_list, &buf->rb_mws);
@@ -71,12 +95,24 @@ fmr_op_init(struct rpcrdma_xprt *r_xprt)
 	return 0;
 
 out_fmr_err:
-	rc = PTR_ERR(r->r.fmr);
+	rc = PTR_ERR(r->r.fmr.fmr);
 	dprintk("RPC:       %s: ib_alloc_fmr status %i\n", __func__, rc);
+	kfree(r->r.fmr.physaddrs);
+out_free:
 	kfree(r);
+out:
 	return rc;
 }
 
+static int
+__fmr_unmap(struct rpcrdma_mw *r)
+{
+	LIST_HEAD(l);
+
+	list_add(&r->r.fmr.fmr->list, &l);
+	return ib_unmap_fmr(&l);
+}
+
 /* Use the ib_map_phys_fmr() verb to register a memory region
  * for remote access via RDMA READ or RDMA WRITE.
  */
@@ -85,12 +121,24 @@ fmr_op_map(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg,
 	   int nsegs, bool writing)
 {
 	struct rpcrdma_ia *ia = &r_xprt->rx_ia;
-	struct ib_device *device = ia->ri_id->device;
+	struct ib_device *device = ia->ri_device;
 	enum dma_data_direction direction = rpcrdma_data_dir(writing);
 	struct rpcrdma_mr_seg *seg1 = seg;
-	struct rpcrdma_mw *mw = seg1->rl_mw;
-	u64 physaddrs[RPCRDMA_MAX_DATA_SEGS];
 	int len, pageoff, i, rc;
+	struct rpcrdma_mw *mw;
+
+	mw = seg1->rl_mw;
+	seg1->rl_mw = NULL;
+	if (!mw) {
+		mw = rpcrdma_get_mw(r_xprt);
+		if (!mw)
+			return -ENOMEM;
+	} else {
+		/* this is a retransmit; generate a fresh rkey */
+		rc = __fmr_unmap(mw);
+		if (rc)
+			return rc;
+	}
 
 	pageoff = offset_in_page(seg1->mr_offset);
 	seg1->mr_offset -= pageoff;	/* start of page */
@@ -100,7 +148,7 @@ fmr_op_map(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg,
 		nsegs = RPCRDMA_MAX_FMR_SGES;
 	for (i = 0; i < nsegs;) {
 		rpcrdma_map_one(device, seg, direction);
-		physaddrs[i] = seg->mr_dma;
+		mw->r.fmr.physaddrs[i] = seg->mr_dma;
 		len += seg->mr_len;
 		++seg;
 		++i;
@@ -110,11 +158,13 @@ fmr_op_map(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg,
 			break;
 	}
 
-	rc = ib_map_phys_fmr(mw->r.fmr, physaddrs, i, seg1->mr_dma);
+	rc = ib_map_phys_fmr(mw->r.fmr.fmr, mw->r.fmr.physaddrs,
+			     i, seg1->mr_dma);
 	if (rc)
 		goto out_maperr;
 
-	seg1->mr_rkey = mw->r.fmr->rkey;
+	seg1->rl_mw = mw;
+	seg1->mr_rkey = mw->r.fmr.fmr->rkey;
 	seg1->mr_base = seg1->mr_dma + pageoff;
 	seg1->mr_nsegs = i;
 	seg1->mr_len = len;
@@ -137,48 +187,28 @@ fmr_op_unmap(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg)
 {
 	struct rpcrdma_ia *ia = &r_xprt->rx_ia;
 	struct rpcrdma_mr_seg *seg1 = seg;
-	struct ib_device *device;
+	struct rpcrdma_mw *mw = seg1->rl_mw;
 	int rc, nsegs = seg->mr_nsegs;
-	LIST_HEAD(l);
 
-	list_add(&seg1->rl_mw->r.fmr->list, &l);
-	rc = ib_unmap_fmr(&l);
-	read_lock(&ia->ri_qplock);
-	device = ia->ri_id->device;
+	dprintk("RPC:       %s: FMR %p\n", __func__, mw);
+
+	seg1->rl_mw = NULL;
 	while (seg1->mr_nsegs--)
-		rpcrdma_unmap_one(device, seg++);
-	read_unlock(&ia->ri_qplock);
+		rpcrdma_unmap_one(ia->ri_device, seg++);
+	rc = __fmr_unmap(mw);
 	if (rc)
 		goto out_err;
+	rpcrdma_put_mw(r_xprt, mw);
 	return nsegs;
 
 out_err:
+	/* The FMR is abandoned, but remains in rb_all. fmr_op_destroy
+	 * will attempt to release it when the transport is destroyed.
+	 */
 	dprintk("RPC:       %s: ib_unmap_fmr status %i\n", __func__, rc);
 	return nsegs;
 }
 
-/* After a disconnect, unmap all FMRs.
- *
- * This is invoked only in the transport connect worker in order
- * to serialize with rpcrdma_register_fmr_external().
- */
-static void
-fmr_op_reset(struct rpcrdma_xprt *r_xprt)
-{
-	struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
-	struct rpcrdma_mw *r;
-	LIST_HEAD(list);
-	int rc;
-
-	list_for_each_entry(r, &buf->rb_all, mw_all)
-		list_add(&r->r.fmr->list, &list);
-
-	rc = ib_unmap_fmr(&list);
-	if (rc)
-		dprintk("RPC:       %s: ib_unmap_fmr failed %i\n",
-			__func__, rc);
-}
-
 static void
 fmr_op_destroy(struct rpcrdma_buffer *buf)
 {
@@ -188,10 +218,13 @@ fmr_op_destroy(struct rpcrdma_buffer *buf)
 	while (!list_empty(&buf->rb_all)) {
 		r = list_entry(buf->rb_all.next, struct rpcrdma_mw, mw_all);
 		list_del(&r->mw_all);
-		rc = ib_dealloc_fmr(r->r.fmr);
+		kfree(r->r.fmr.physaddrs);
+
+		rc = ib_dealloc_fmr(r->r.fmr.fmr);
 		if (rc)
 			dprintk("RPC:       %s: ib_dealloc_fmr failed %i\n",
 				__func__, rc);
+
 		kfree(r);
 	}
 }
@@ -202,7 +235,6 @@ const struct rpcrdma_memreg_ops rpcrdma_fmr_memreg_ops = {
 	.ro_open			= fmr_op_open,
 	.ro_maxpages			= fmr_op_maxpages,
 	.ro_init			= fmr_op_init,
-	.ro_reset			= fmr_op_reset,
 	.ro_destroy			= fmr_op_destroy,
 	.ro_displayname			= "fmr",
 };
diff --git a/kernel/net/sunrpc/xprtrdma/frwr_ops.c b/kernel/net/sunrpc/xprtrdma/frwr_ops.c
index dff0481db..88cf9e726 100644
--- a/kernel/net/sunrpc/xprtrdma/frwr_ops.c
+++ b/kernel/net/sunrpc/xprtrdma/frwr_ops.c
@@ -11,12 +11,136 @@
  * but most complex memory registration mode.
  */
 
+/* Normal operation
+ *
+ * A Memory Region is prepared for RDMA READ or WRITE using a FAST_REG
+ * Work Request (frmr_op_map). When the RDMA operation is finished, this
+ * Memory Region is invalidated using a LOCAL_INV Work Request
+ * (frmr_op_unmap).
+ *
+ * Typically these Work Requests are not signaled, and neither are RDMA
+ * SEND Work Requests (with the exception of signaling occasionally to
+ * prevent provider work queue overflows). This greatly reduces HCA
+ * interrupt workload.
+ *
+ * As an optimization, frwr_op_unmap marks MRs INVALID before the
+ * LOCAL_INV WR is posted. If posting succeeds, the MR is placed on
+ * rb_mws immediately so that no work (like managing a linked list
+ * under a spinlock) is needed in the completion upcall.
+ *
+ * But this means that frwr_op_map() can occasionally encounter an MR
+ * that is INVALID but the LOCAL_INV WR has not completed. Work Queue
+ * ordering prevents a subsequent FAST_REG WR from executing against
+ * that MR while it is still being invalidated.
+ */
+
+/* Transport recovery
+ *
+ * ->op_map and the transport connect worker cannot run at the same
+ * time, but ->op_unmap can fire while the transport connect worker
+ * is running. Thus MR recovery is handled in ->op_map, to guarantee
+ * that recovered MRs are owned by a sending RPC, and not one where
+ * ->op_unmap could fire at the same time transport reconnect is
+ * being done.
+ *
+ * When the underlying transport disconnects, MRs are left in one of
+ * three states:
+ *
+ * INVALID:	The MR was not in use before the QP entered ERROR state.
+ *		(Or, the LOCAL_INV WR has not completed or flushed yet).
+ *
+ * STALE:	The MR was being registered or unregistered when the QP
+ *		entered ERROR state, and the pending WR was flushed.
+ *
+ * VALID:	The MR was registered before the QP entered ERROR state.
+ *
+ * When frwr_op_map encounters STALE and VALID MRs, they are recovered
+ * with ib_dereg_mr and then are re-initialized. Beause MR recovery
+ * allocates fresh resources, it is deferred to a workqueue, and the
+ * recovered MRs are placed back on the rb_mws list when recovery is
+ * complete. frwr_op_map allocates another MR for the current RPC while
+ * the broken MR is reset.
+ *
+ * To ensure that frwr_op_map doesn't encounter an MR that is marked
+ * INVALID but that is about to be flushed due to a previous transport
+ * disconnect, the transport connect worker attempts to drain all
+ * pending send queue WRs before the transport is reconnected.
+ */
+
 #include "xprt_rdma.h"
 
 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 # define RPCDBG_FACILITY	RPCDBG_TRANS
 #endif
 
+static struct workqueue_struct *frwr_recovery_wq;
+
+#define FRWR_RECOVERY_WQ_FLAGS		(WQ_UNBOUND | WQ_MEM_RECLAIM)
+
+int
+frwr_alloc_recovery_wq(void)
+{
+	frwr_recovery_wq = alloc_workqueue("frwr_recovery",
+					   FRWR_RECOVERY_WQ_FLAGS, 0);
+	return !frwr_recovery_wq ? -ENOMEM : 0;
+}
+
+void
+frwr_destroy_recovery_wq(void)
+{
+	struct workqueue_struct *wq;
+
+	if (!frwr_recovery_wq)
+		return;
+
+	wq = frwr_recovery_wq;
+	frwr_recovery_wq = NULL;
+	destroy_workqueue(wq);
+}
+
+/* Deferred reset of a single FRMR. Generate a fresh rkey by
+ * replacing the MR.
+ *
+ * There's no recovery if this fails. The FRMR is abandoned, but
+ * remains in rb_all. It will be cleaned up when the transport is
+ * destroyed.
+ */
+static void
+__frwr_recovery_worker(struct work_struct *work)
+{
+	struct rpcrdma_mw *r = container_of(work, struct rpcrdma_mw,
+					    r.frmr.fr_work);
+	struct rpcrdma_xprt *r_xprt = r->r.frmr.fr_xprt;
+	unsigned int depth = r_xprt->rx_ia.ri_max_frmr_depth;
+	struct ib_pd *pd = r_xprt->rx_ia.ri_pd;
+
+	if (ib_dereg_mr(r->r.frmr.fr_mr))
+		goto out_fail;
+
+	r->r.frmr.fr_mr = ib_alloc_mr(pd, IB_MR_TYPE_MEM_REG, depth);
+	if (IS_ERR(r->r.frmr.fr_mr))
+		goto out_fail;
+
+	dprintk("RPC:       %s: recovered FRMR %p\n", __func__, r);
+	r->r.frmr.fr_state = FRMR_IS_INVALID;
+	rpcrdma_put_mw(r_xprt, r);
+	return;
+
+out_fail:
+	pr_warn("RPC:       %s: FRMR %p unrecovered\n",
+		__func__, r);
+}
+
+/* A broken MR was discovered in a context that can't sleep.
+ * Defer recovery to the recovery worker.
+ */
+static void
+__frwr_queue_recovery(struct rpcrdma_mw *r)
+{
+	INIT_WORK(&r->r.frmr.fr_work, __frwr_recovery_worker);
+	queue_work(frwr_recovery_wq, &r->r.frmr.fr_work);
+}
+
 static int
 __frwr_init(struct rpcrdma_mw *r, struct ib_pd *pd, struct ib_device *device,
 	    unsigned int depth)
@@ -24,24 +148,28 @@ __frwr_init(struct rpcrdma_mw *r, struct ib_pd *pd, struct ib_device *device,
 	struct rpcrdma_frmr *f = &r->r.frmr;
 	int rc;
 
-	f->fr_mr = ib_alloc_fast_reg_mr(pd, depth);
+	f->fr_mr = ib_alloc_mr(pd, IB_MR_TYPE_MEM_REG, depth);
 	if (IS_ERR(f->fr_mr))
 		goto out_mr_err;
-	f->fr_pgl = ib_alloc_fast_reg_page_list(device, depth);
-	if (IS_ERR(f->fr_pgl))
+
+	f->sg = kcalloc(depth, sizeof(*f->sg), GFP_KERNEL);
+	if (!f->sg)
 		goto out_list_err;
+
+	sg_init_table(f->sg, depth);
+
 	return 0;
 
 out_mr_err:
 	rc = PTR_ERR(f->fr_mr);
-	dprintk("RPC:       %s: ib_alloc_fast_reg_mr status %i\n",
+	dprintk("RPC:       %s: ib_alloc_mr status %i\n",
 		__func__, rc);
 	return rc;
 
 out_list_err:
-	rc = PTR_ERR(f->fr_pgl);
-	dprintk("RPC:       %s: ib_alloc_fast_reg_page_list status %i\n",
-		__func__, rc);
+	rc = -ENOMEM;
+	dprintk("RPC:       %s: sg allocation failure\n",
+		__func__);
 	ib_dereg_mr(f->fr_mr);
 	return rc;
 }
@@ -55,7 +183,7 @@ __frwr_release(struct rpcrdma_mw *r)
 	if (rc)
 		dprintk("RPC:       %s: ib_dereg_mr status %i\n",
 			__func__, rc);
-	ib_free_fast_reg_page_list(r->r.frmr.fr_pgl);
+	kfree(r->r.frmr.sg);
 }
 
 static int
@@ -128,8 +256,11 @@ frwr_sendcompletion(struct ib_wc *wc)
 
 	/* WARNING: Only wr_id and status are reliable at this point */
 	r = (struct rpcrdma_mw *)(unsigned long)wc->wr_id;
-	dprintk("RPC:       %s: frmr %p (stale), status %d\n",
-		__func__, r, wc->status);
+	if (wc->status == IB_WC_WR_FLUSH_ERR)
+		dprintk("RPC:       %s: frmr %p flushed\n", __func__, r);
+	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;
 }
 
@@ -137,16 +268,19 @@ static int
 frwr_op_init(struct rpcrdma_xprt *r_xprt)
 {
 	struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
-	struct ib_device *device = r_xprt->rx_ia.ri_id->device;
+	struct ib_device *device = r_xprt->rx_ia.ri_device;
 	unsigned int depth = r_xprt->rx_ia.ri_max_frmr_depth;
 	struct ib_pd *pd = r_xprt->rx_ia.ri_pd;
 	int i;
 
+	spin_lock_init(&buf->rb_mwlock);
 	INIT_LIST_HEAD(&buf->rb_mws);
 	INIT_LIST_HEAD(&buf->rb_all);
 
-	i = (buf->rb_max_requests + 1) * RPCRDMA_MAX_SEGS;
-	dprintk("RPC:       %s: initializing %d FRMRs\n", __func__, i);
+	i = max_t(int, RPCRDMA_MAX_DATA_SEGS / depth, 1);
+	i += 2;				/* head + tail */
+	i *= buf->rb_max_requests;	/* one set for each RPC slot */
+	dprintk("RPC:       %s: initalizing %d FRMRs\n", __func__, i);
 
 	while (i--) {
 		struct rpcrdma_mw *r;
@@ -165,6 +299,7 @@ frwr_op_init(struct rpcrdma_xprt *r_xprt)
 		list_add(&r->mw_list, &buf->rb_mws);
 		list_add(&r->mw_all, &buf->rb_all);
 		r->mw_sendcompletion = frwr_sendcompletion;
+		r->r.frmr.fr_xprt = r_xprt;
 	}
 
 	return 0;
@@ -178,78 +313,103 @@ frwr_op_map(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg,
 	    int nsegs, bool writing)
 {
 	struct rpcrdma_ia *ia = &r_xprt->rx_ia;
-	struct ib_device *device = ia->ri_id->device;
+	struct ib_device *device = ia->ri_device;
 	enum dma_data_direction direction = rpcrdma_data_dir(writing);
 	struct rpcrdma_mr_seg *seg1 = seg;
-	struct rpcrdma_mw *mw = seg1->rl_mw;
-	struct rpcrdma_frmr *frmr = &mw->r.frmr;
-	struct ib_mr *mr = frmr->fr_mr;
-	struct ib_send_wr fastreg_wr, *bad_wr;
+	struct rpcrdma_mw *mw;
+	struct rpcrdma_frmr *frmr;
+	struct ib_mr *mr;
+	struct ib_reg_wr reg_wr;
+	struct ib_send_wr *bad_wr;
+	int rc, i, n, dma_nents;
 	u8 key;
-	int len, pageoff;
-	int i, rc;
-	int seg_len;
-	u64 pa;
-	int page_no;
-
-	pageoff = offset_in_page(seg1->mr_offset);
-	seg1->mr_offset -= pageoff;	/* start of page */
-	seg1->mr_len += pageoff;
-	len = -pageoff;
+
+	mw = seg1->rl_mw;
+	seg1->rl_mw = NULL;
+	do {
+		if (mw)
+			__frwr_queue_recovery(mw);
+		mw = rpcrdma_get_mw(r_xprt);
+		if (!mw)
+			return -ENOMEM;
+	} while (mw->r.frmr.fr_state != FRMR_IS_INVALID);
+	frmr = &mw->r.frmr;
+	frmr->fr_state = FRMR_IS_VALID;
+	mr = frmr->fr_mr;
+
 	if (nsegs > ia->ri_max_frmr_depth)
 		nsegs = ia->ri_max_frmr_depth;
-	for (page_no = i = 0; i < nsegs;) {
-		rpcrdma_map_one(device, seg, direction);
-		pa = seg->mr_dma;
-		for (seg_len = seg->mr_len; seg_len > 0; seg_len -= PAGE_SIZE) {
-			frmr->fr_pgl->page_list[page_no++] = pa;
-			pa += PAGE_SIZE;
-		}
-		len += seg->mr_len;
+
+	for (i = 0; i < nsegs;) {
+		if (seg->mr_page)
+			sg_set_page(&frmr->sg[i],
+				    seg->mr_page,
+				    seg->mr_len,
+				    offset_in_page(seg->mr_offset));
+		else
+			sg_set_buf(&frmr->sg[i], seg->mr_offset,
+				   seg->mr_len);
+
 		++seg;
 		++i;
+
 		/* Check for holes */
 		if ((i < nsegs && offset_in_page(seg->mr_offset)) ||
 		    offset_in_page((seg-1)->mr_offset + (seg-1)->mr_len))
 			break;
 	}
-	dprintk("RPC:       %s: Using frmr %p to map %d segments (%d bytes)\n",
-		__func__, mw, i, len);
+	frmr->sg_nents = i;
 
-	frmr->fr_state = FRMR_IS_VALID;
+	dma_nents = ib_dma_map_sg(device, frmr->sg, frmr->sg_nents, direction);
+	if (!dma_nents) {
+		pr_err("RPC:       %s: failed to dma map sg %p sg_nents %u\n",
+		       __func__, frmr->sg, frmr->sg_nents);
+		return -ENOMEM;
+	}
+
+	n = ib_map_mr_sg(mr, frmr->sg, frmr->sg_nents, PAGE_SIZE);
+	if (unlikely(n != frmr->sg_nents)) {
+		pr_err("RPC:       %s: failed to map mr %p (%u/%u)\n",
+		       __func__, frmr->fr_mr, n, frmr->sg_nents);
+		rc = n < 0 ? n : -EINVAL;
+		goto out_senderr;
+	}
+
+	dprintk("RPC:       %s: Using frmr %p to map %u segments (%u bytes)\n",
+		__func__, mw, frmr->sg_nents, mr->length);
 
-	memset(&fastreg_wr, 0, sizeof(fastreg_wr));
-	fastreg_wr.wr_id = (unsigned long)(void *)mw;
-	fastreg_wr.opcode = IB_WR_FAST_REG_MR;
-	fastreg_wr.wr.fast_reg.iova_start = seg1->mr_dma + pageoff;
-	fastreg_wr.wr.fast_reg.page_list = frmr->fr_pgl;
-	fastreg_wr.wr.fast_reg.page_shift = PAGE_SHIFT;
-	fastreg_wr.wr.fast_reg.page_list_len = page_no;
-	fastreg_wr.wr.fast_reg.length = len;
-	fastreg_wr.wr.fast_reg.access_flags = writing ?
-				IB_ACCESS_REMOTE_WRITE | IB_ACCESS_LOCAL_WRITE :
-				IB_ACCESS_REMOTE_READ;
 	key = (u8)(mr->rkey & 0x000000FF);
 	ib_update_fast_reg_key(mr, ++key);
-	fastreg_wr.wr.fast_reg.rkey = mr->rkey;
+
+	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, &fastreg_wr, &bad_wr);
+	rc = ib_post_send(ia->ri_id->qp, &reg_wr.wr, &bad_wr);
 	if (rc)
 		goto out_senderr;
 
+	seg1->mr_dir = direction;
+	seg1->rl_mw = mw;
 	seg1->mr_rkey = mr->rkey;
-	seg1->mr_base = seg1->mr_dma + pageoff;
-	seg1->mr_nsegs = i;
-	seg1->mr_len = len;
-	return i;
+	seg1->mr_base = mr->iova;
+	seg1->mr_nsegs = frmr->sg_nents;
+	seg1->mr_len = mr->length;
+
+	return frmr->sg_nents;
 
 out_senderr:
 	dprintk("RPC:       %s: ib_post_send status %i\n", __func__, rc);
-	ib_update_fast_reg_key(mr, --key);
-	frmr->fr_state = FRMR_IS_INVALID;
-	while (i--)
-		rpcrdma_unmap_one(device, --seg);
+	ib_dma_unmap_sg(device, frmr->sg, dma_nents, direction);
+	__frwr_queue_recovery(mw);
 	return rc;
 }
 
@@ -261,78 +421,46 @@ frwr_op_unmap(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg)
 {
 	struct rpcrdma_mr_seg *seg1 = 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;
 	int rc, nsegs = seg->mr_nsegs;
-	struct ib_device *device;
 
-	seg1->rl_mw->r.frmr.fr_state = FRMR_IS_INVALID;
+	dprintk("RPC:       %s: FRMR %p\n", __func__, mw);
+
+	seg1->rl_mw = NULL;
+	frmr->fr_state = FRMR_IS_INVALID;
 
 	memset(&invalidate_wr, 0, sizeof(invalidate_wr));
-	invalidate_wr.wr_id = (unsigned long)(void *)seg1->rl_mw;
+	invalidate_wr.wr_id = (unsigned long)(void *)mw;
 	invalidate_wr.opcode = IB_WR_LOCAL_INV;
-	invalidate_wr.ex.invalidate_rkey = seg1->rl_mw->r.frmr.fr_mr->rkey;
+	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);
-	device = ia->ri_id->device;
-	while (seg1->mr_nsegs--)
-		rpcrdma_unmap_one(device, seg++);
 	rc = ib_post_send(ia->ri_id->qp, &invalidate_wr, &bad_wr);
 	read_unlock(&ia->ri_qplock);
 	if (rc)
 		goto out_err;
+
+	rpcrdma_put_mw(r_xprt, mw);
 	return nsegs;
 
 out_err:
-	/* Force rpcrdma_buffer_get() to retry */
-	seg1->rl_mw->r.frmr.fr_state = FRMR_IS_STALE;
 	dprintk("RPC:       %s: ib_post_send status %i\n", __func__, rc);
+	__frwr_queue_recovery(mw);
 	return nsegs;
 }
 
-/* After a disconnect, a flushed FAST_REG_MR can leave an FRMR in
- * an unusable state. Find FRMRs in this state and dereg / reg
- * each.  FRMRs that are VALID and attached to an rpcrdma_req are
- * also torn down.
- *
- * This gives all in-use FRMRs a fresh rkey and leaves them INVALID.
- *
- * This is invoked only in the transport connect worker in order
- * to serialize with rpcrdma_register_frmr_external().
- */
-static void
-frwr_op_reset(struct rpcrdma_xprt *r_xprt)
-{
-	struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
-	struct ib_device *device = r_xprt->rx_ia.ri_id->device;
-	unsigned int depth = r_xprt->rx_ia.ri_max_frmr_depth;
-	struct ib_pd *pd = r_xprt->rx_ia.ri_pd;
-	struct rpcrdma_mw *r;
-	int rc;
-
-	list_for_each_entry(r, &buf->rb_all, mw_all) {
-		if (r->r.frmr.fr_state == FRMR_IS_INVALID)
-			continue;
-
-		__frwr_release(r);
-		rc = __frwr_init(r, pd, device, depth);
-		if (rc) {
-			dprintk("RPC:       %s: mw %p left %s\n",
-				__func__, r,
-				(r->r.frmr.fr_state == FRMR_IS_STALE ?
-					"stale" : "valid"));
-			continue;
-		}
-
-		r->r.frmr.fr_state = FRMR_IS_INVALID;
-	}
-}
-
 static void
 frwr_op_destroy(struct rpcrdma_buffer *buf)
 {
 	struct rpcrdma_mw *r;
 
+	/* Ensure stale MWs for "buf" are no longer in flight */
+	flush_workqueue(frwr_recovery_wq);
+
 	while (!list_empty(&buf->rb_all)) {
 		r = list_entry(buf->rb_all.next, struct rpcrdma_mw, mw_all);
 		list_del(&r->mw_all);
@@ -347,7 +475,6 @@ const struct rpcrdma_memreg_ops rpcrdma_frwr_memreg_ops = {
 	.ro_open			= frwr_op_open,
 	.ro_maxpages			= frwr_op_maxpages,
 	.ro_init			= frwr_op_init,
-	.ro_reset			= frwr_op_reset,
 	.ro_destroy			= frwr_op_destroy,
 	.ro_displayname			= "frwr",
 };
diff --git a/kernel/net/sunrpc/xprtrdma/module.c b/kernel/net/sunrpc/xprtrdma/module.c
new file mode 100644
index 000000000..560712bd9
--- /dev/null
+++ b/kernel/net/sunrpc/xprtrdma/module.c
@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2015 Oracle.  All rights reserved.
+ */
+
+/* rpcrdma.ko module initialization
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/sunrpc/svc_rdma.h>
+#include "xprt_rdma.h"
+
+#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
+# define RPCDBG_FACILITY	RPCDBG_TRANS
+#endif
+
+MODULE_AUTHOR("Open Grid Computing and Network Appliance, Inc.");
+MODULE_DESCRIPTION("RPC/RDMA Transport");
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_ALIAS("svcrdma");
+MODULE_ALIAS("xprtrdma");
+
+static void __exit rpc_rdma_cleanup(void)
+{
+	xprt_rdma_cleanup();
+	svc_rdma_cleanup();
+}
+
+static int __init rpc_rdma_init(void)
+{
+	int rc;
+
+	rc = svc_rdma_init();
+	if (rc)
+		goto out;
+
+	rc = xprt_rdma_init();
+	if (rc)
+		svc_rdma_cleanup();
+
+out:
+	return rc;
+}
+
+module_init(rpc_rdma_init);
+module_exit(rpc_rdma_cleanup);
diff --git a/kernel/net/sunrpc/xprtrdma/physical_ops.c b/kernel/net/sunrpc/xprtrdma/physical_ops.c
index ba518af16..617b76f22 100644
--- a/kernel/net/sunrpc/xprtrdma/physical_ops.c
+++ b/kernel/net/sunrpc/xprtrdma/physical_ops.c
@@ -23,6 +23,21 @@ static int
 physical_op_open(struct rpcrdma_ia *ia, struct rpcrdma_ep *ep,
 		 struct rpcrdma_create_data_internal *cdata)
 {
+	struct ib_mr *mr;
+
+	/* Obtain an rkey to use for RPC data payloads.
+	 */
+	mr = ib_get_dma_mr(ia->ri_pd,
+			   IB_ACCESS_LOCAL_WRITE |
+			   IB_ACCESS_REMOTE_WRITE |
+			   IB_ACCESS_REMOTE_READ);
+	if (IS_ERR(mr)) {
+		pr_err("%s: ib_get_dma_mr for failed with %lX\n",
+		       __func__, PTR_ERR(mr));
+		return -ENOMEM;
+	}
+
+	ia->ri_dma_mr = mr;
 	return 0;
 }
 
@@ -50,9 +65,8 @@ physical_op_map(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg,
 {
 	struct rpcrdma_ia *ia = &r_xprt->rx_ia;
 
-	rpcrdma_map_one(ia->ri_id->device, seg,
-			rpcrdma_data_dir(writing));
-	seg->mr_rkey = ia->ri_bind_mem->rkey;
+	rpcrdma_map_one(ia->ri_device, seg, rpcrdma_data_dir(writing));
+	seg->mr_rkey = ia->ri_dma_mr->rkey;
 	seg->mr_base = seg->mr_dma;
 	seg->mr_nsegs = 1;
 	return 1;
@@ -65,19 +79,11 @@ physical_op_unmap(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg)
 {
 	struct rpcrdma_ia *ia = &r_xprt->rx_ia;
 
-	read_lock(&ia->ri_qplock);
-	rpcrdma_unmap_one(ia->ri_id->device, seg);
-	read_unlock(&ia->ri_qplock);
-
+	rpcrdma_unmap_one(ia->ri_device, seg);
 	return 1;
 }
 
 static void
-physical_op_reset(struct rpcrdma_xprt *r_xprt)
-{
-}
-
-static void
 physical_op_destroy(struct rpcrdma_buffer *buf)
 {
 }
@@ -88,7 +94,6 @@ const struct rpcrdma_memreg_ops rpcrdma_physical_memreg_ops = {
 	.ro_open			= physical_op_open,
 	.ro_maxpages			= physical_op_maxpages,
 	.ro_init			= physical_op_init,
-	.ro_reset			= physical_op_reset,
 	.ro_destroy			= physical_op_destroy,
 	.ro_displayname			= "physical",
 };
diff --git a/kernel/net/sunrpc/xprtrdma/rpc_rdma.c b/kernel/net/sunrpc/xprtrdma/rpc_rdma.c
index 2c53ea9e1..c10d96994 100644
--- a/kernel/net/sunrpc/xprtrdma/rpc_rdma.c
+++ b/kernel/net/sunrpc/xprtrdma/rpc_rdma.c
@@ -71,6 +71,67 @@ static const char transfertypes[][12] = {
 };
 #endif
 
+/* The client can send a request inline as long as the RPCRDMA header
+ * plus the RPC call fit under the transport's inline limit. If the
+ * combined call message size exceeds that limit, the client must use
+ * the read chunk list for this operation.
+ */
+static bool rpcrdma_args_inline(struct rpc_rqst *rqst)
+{
+	unsigned int callsize = RPCRDMA_HDRLEN_MIN + rqst->rq_snd_buf.len;
+
+	return callsize <= RPCRDMA_INLINE_WRITE_THRESHOLD(rqst);
+}
+
+/* The client can't know how large the actual reply will be. Thus it
+ * plans for the largest possible reply for that particular ULP
+ * operation. If the maximum combined reply message size exceeds that
+ * limit, the client must provide a write list or a reply chunk for
+ * this request.
+ */
+static bool rpcrdma_results_inline(struct rpc_rqst *rqst)
+{
+	unsigned int repsize = RPCRDMA_HDRLEN_MIN + rqst->rq_rcv_buf.buflen;
+
+	return repsize <= RPCRDMA_INLINE_READ_THRESHOLD(rqst);
+}
+
+static int
+rpcrdma_tail_pullup(struct xdr_buf *buf)
+{
+	size_t tlen = buf->tail[0].iov_len;
+	size_t skip = tlen & 3;
+
+	/* Do not include the tail if it is only an XDR pad */
+	if (tlen < 4)
+		return 0;
+
+	/* xdr_write_pages() adds a pad at the beginning of the tail
+	 * if the content in "buf->pages" is unaligned. Force the
+	 * tail's actual content to land at the next XDR position
+	 * after the head instead.
+	 */
+	if (skip) {
+		unsigned char *src, *dst;
+		unsigned int count;
+
+		src = buf->tail[0].iov_base;
+		dst = buf->head[0].iov_base;
+		dst += buf->head[0].iov_len;
+
+		src += skip;
+		tlen -= skip;
+
+		dprintk("RPC:       %s: skip=%zu, memmove(%p, %p, %zu)\n",
+			__func__, skip, dst, src, tlen);
+
+		for (count = tlen; count; count--)
+			*dst++ = *src++;
+	}
+
+	return tlen;
+}
+
 /*
  * Chunk assembly from upper layer xdr_buf.
  *
@@ -122,6 +183,10 @@ rpcrdma_convert_iovs(struct xdr_buf *xdrbuf, unsigned int pos,
 	if (len && n == nsegs)
 		return -EIO;
 
+	/* When encoding the read list, the tail is always sent inline */
+	if (type == rpcrdma_readch)
+		return n;
+
 	if (xdrbuf->tail[0].iov_len) {
 		/* the rpcrdma protocol allows us to omit any trailing
 		 * xdr pad bytes, saving the server an RDMA operation. */
@@ -284,9 +349,6 @@ rpcrdma_create_chunks(struct rpc_rqst *rqst, struct xdr_buf *target,
 	return (unsigned char *)iptr - (unsigned char *)headerp;
 
 out:
-	if (r_xprt->rx_ia.ri_memreg_strategy == RPCRDMA_FRMR)
-		return n;
-
 	for (pos = 0; nchunks--;)
 		pos += r_xprt->rx_ia.ri_ops->ro_unmap(r_xprt,
 						      &req->rl_segments[pos]);
@@ -300,8 +362,7 @@ out:
  * pre-registered memory buffer for this request. For small amounts
  * of data, this is efficient. The cutoff value is tunable.
  */
-static int
-rpcrdma_inline_pullup(struct rpc_rqst *rqst, int pad)
+static void rpcrdma_inline_pullup(struct rpc_rqst *rqst)
 {
 	int i, npages, curlen;
 	int copy_len;
@@ -313,16 +374,9 @@ rpcrdma_inline_pullup(struct rpc_rqst *rqst, int pad)
 	destp = rqst->rq_svec[0].iov_base;
 	curlen = rqst->rq_svec[0].iov_len;
 	destp += curlen;
-	/*
-	 * Do optional padding where it makes sense. Alignment of write
-	 * payload can help the server, if our setting is accurate.
-	 */
-	pad -= (curlen + 36/*sizeof(struct rpcrdma_msg_padded)*/);
-	if (pad < 0 || rqst->rq_slen - curlen < RPCRDMA_INLINE_PAD_THRESH)
-		pad = 0;	/* don't pad this request */
 
-	dprintk("RPC:       %s: pad %d destp 0x%p len %d hdrlen %d\n",
-		__func__, pad, destp, rqst->rq_slen, curlen);
+	dprintk("RPC:       %s: destp 0x%p len %d hdrlen %d\n",
+		__func__, destp, rqst->rq_slen, curlen);
 
 	copy_len = rqst->rq_snd_buf.page_len;
 
@@ -358,7 +412,6 @@ rpcrdma_inline_pullup(struct rpc_rqst *rqst, int pad)
 		page_base = 0;
 	}
 	/* header now contains entire send message */
-	return pad;
 }
 
 /*
@@ -383,11 +436,16 @@ rpcrdma_marshal_req(struct rpc_rqst *rqst)
 	struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 	struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
 	char *base;
-	size_t rpclen, padlen;
+	size_t rpclen;
 	ssize_t hdrlen;
 	enum rpcrdma_chunktype rtype, wtype;
 	struct rpcrdma_msg *headerp;
 
+#if defined(CONFIG_SUNRPC_BACKCHANNEL)
+	if (test_bit(RPC_BC_PA_IN_USE, &rqst->rq_bc_pa_state))
+		return rpcrdma_bc_marshal_reply(rqst);
+#endif
+
 	/*
 	 * rpclen gets amount of data in first buffer, which is the
 	 * pre-registered buffer.
@@ -405,28 +463,15 @@ rpcrdma_marshal_req(struct rpc_rqst *rqst)
 	/*
 	 * Chunks needed for results?
 	 *
+	 * o Read ops return data as write chunk(s), header as inline.
 	 * o If the expected result is under the inline threshold, all ops
-	 *   return as inline (but see later).
+	 *   return as inline.
 	 * o Large non-read ops return as a single reply chunk.
-	 * o Large read ops return data as write chunk(s), header as inline.
-	 *
-	 * Note: the NFS code sending down multiple result segments implies
-	 * the op is one of read, readdir[plus], readlink or NFSv4 getacl.
-	 */
-
-	/*
-	 * This code can handle read chunks, write chunks OR reply
-	 * chunks -- only one type. If the request is too big to fit
-	 * inline, then we will choose read chunks. If the request is
-	 * a READ, then use write chunks to separate the file data
-	 * into pages; otherwise use reply chunks.
 	 */
-	if (rqst->rq_rcv_buf.buflen <= RPCRDMA_INLINE_READ_THRESHOLD(rqst))
-		wtype = rpcrdma_noch;
-	else if (rqst->rq_rcv_buf.page_len == 0)
-		wtype = rpcrdma_replych;
-	else if (rqst->rq_rcv_buf.flags & XDRBUF_READ)
+	if (rqst->rq_rcv_buf.flags & XDRBUF_READ)
 		wtype = rpcrdma_writech;
+	else if (rpcrdma_results_inline(rqst))
+		wtype = rpcrdma_noch;
 	else
 		wtype = rpcrdma_replych;
 
@@ -435,21 +480,25 @@ rpcrdma_marshal_req(struct rpc_rqst *rqst)
 	 *
 	 * o If the total request is under the inline threshold, all ops
 	 *   are sent as inline.
-	 * o Large non-write ops are sent with the entire message as a
-	 *   single read chunk (protocol 0-position special case).
 	 * o Large write ops transmit data as read chunk(s), header as
 	 *   inline.
+	 * o Large non-write ops are sent with the entire message as a
+	 *   single read chunk (protocol 0-position special case).
 	 *
-	 * Note: the NFS code sending down multiple argument segments
-	 * implies the op is a write.
-	 * TBD check NFSv4 setacl
+	 * This assumes that the upper layer does not present a request
+	 * that both has a data payload, and whose non-data arguments
+	 * by themselves are larger than the inline threshold.
 	 */
-	if (rqst->rq_snd_buf.len <= RPCRDMA_INLINE_WRITE_THRESHOLD(rqst))
+	if (rpcrdma_args_inline(rqst)) {
 		rtype = rpcrdma_noch;
-	else if (rqst->rq_snd_buf.page_len == 0)
-		rtype = rpcrdma_areadch;
-	else
+	} else if (rqst->rq_snd_buf.flags & XDRBUF_WRITE) {
 		rtype = rpcrdma_readch;
+	} else {
+		r_xprt->rx_stats.nomsg_call_count++;
+		headerp->rm_type = htonl(RDMA_NOMSG);
+		rtype = rpcrdma_areadch;
+		rpclen = 0;
+	}
 
 	/* The following simplification is not true forever */
 	if (rtype != rpcrdma_noch && wtype == rpcrdma_replych)
@@ -461,7 +510,6 @@ rpcrdma_marshal_req(struct rpc_rqst *rqst)
 	}
 
 	hdrlen = RPCRDMA_HDRLEN_MIN;
-	padlen = 0;
 
 	/*
 	 * Pull up any extra send data into the preregistered buffer.
@@ -470,45 +518,15 @@ rpcrdma_marshal_req(struct rpc_rqst *rqst)
 	 */
 	if (rtype == rpcrdma_noch) {
 
-		padlen = rpcrdma_inline_pullup(rqst,
-						RPCRDMA_INLINE_PAD_VALUE(rqst));
-
-		if (padlen) {
-			headerp->rm_type = rdma_msgp;
-			headerp->rm_body.rm_padded.rm_align =
-				cpu_to_be32(RPCRDMA_INLINE_PAD_VALUE(rqst));
-			headerp->rm_body.rm_padded.rm_thresh =
-				cpu_to_be32(RPCRDMA_INLINE_PAD_THRESH);
-			headerp->rm_body.rm_padded.rm_pempty[0] = xdr_zero;
-			headerp->rm_body.rm_padded.rm_pempty[1] = xdr_zero;
-			headerp->rm_body.rm_padded.rm_pempty[2] = xdr_zero;
-			hdrlen += 2 * sizeof(u32); /* extra words in padhdr */
-			if (wtype != rpcrdma_noch) {
-				dprintk("RPC:       %s: invalid chunk list\n",
-					__func__);
-				return -EIO;
-			}
-		} else {
-			headerp->rm_body.rm_nochunks.rm_empty[0] = xdr_zero;
-			headerp->rm_body.rm_nochunks.rm_empty[1] = xdr_zero;
-			headerp->rm_body.rm_nochunks.rm_empty[2] = xdr_zero;
-			/* new length after pullup */
-			rpclen = rqst->rq_svec[0].iov_len;
-			/*
-			 * Currently we try to not actually use read inline.
-			 * Reply chunks have the desirable property that
-			 * they land, packed, directly in the target buffers
-			 * without headers, so they require no fixup. The
-			 * additional RDMA Write op sends the same amount
-			 * of data, streams on-the-wire and adds no overhead
-			 * on receive. Therefore, we request a reply chunk
-			 * for non-writes wherever feasible and efficient.
-			 */
-			if (wtype == rpcrdma_noch)
-				wtype = rpcrdma_replych;
-		}
-	}
+		rpcrdma_inline_pullup(rqst);
 
+		headerp->rm_body.rm_nochunks.rm_empty[0] = xdr_zero;
+		headerp->rm_body.rm_nochunks.rm_empty[1] = xdr_zero;
+		headerp->rm_body.rm_nochunks.rm_empty[2] = xdr_zero;
+		/* new length after pullup */
+		rpclen = rqst->rq_svec[0].iov_len;
+	} else if (rtype == rpcrdma_readch)
+		rpclen += rpcrdma_tail_pullup(&rqst->rq_snd_buf);
 	if (rtype != rpcrdma_noch) {
 		hdrlen = rpcrdma_create_chunks(rqst, &rqst->rq_snd_buf,
 					       headerp, rtype);
@@ -521,9 +539,9 @@ rpcrdma_marshal_req(struct rpc_rqst *rqst)
 	if (hdrlen < 0)
 		return hdrlen;
 
-	dprintk("RPC:       %s: %s: hdrlen %zd rpclen %zd padlen %zd"
+	dprintk("RPC:       %s: %s: hdrlen %zd rpclen %zd"
 		" headerp 0x%p base 0x%p lkey 0x%x\n",
-		__func__, transfertypes[wtype], hdrlen, rpclen, padlen,
+		__func__, transfertypes[wtype], hdrlen, rpclen,
 		headerp, base, rdmab_lkey(req->rl_rdmabuf));
 
 	/*
@@ -537,26 +555,15 @@ rpcrdma_marshal_req(struct rpc_rqst *rqst)
 	req->rl_send_iov[0].length = hdrlen;
 	req->rl_send_iov[0].lkey = rdmab_lkey(req->rl_rdmabuf);
 
+	req->rl_niovs = 1;
+	if (rtype == rpcrdma_areadch)
+		return 0;
+
 	req->rl_send_iov[1].addr = rdmab_addr(req->rl_sendbuf);
 	req->rl_send_iov[1].length = rpclen;
 	req->rl_send_iov[1].lkey = rdmab_lkey(req->rl_sendbuf);
 
 	req->rl_niovs = 2;
-
-	if (padlen) {
-		struct rpcrdma_ep *ep = &r_xprt->rx_ep;
-
-		req->rl_send_iov[2].addr = rdmab_addr(ep->rep_padbuf);
-		req->rl_send_iov[2].length = padlen;
-		req->rl_send_iov[2].lkey = rdmab_lkey(ep->rep_padbuf);
-
-		req->rl_send_iov[3].addr = req->rl_send_iov[1].addr + rpclen;
-		req->rl_send_iov[3].length = rqst->rq_slen - rpclen;
-		req->rl_send_iov[3].lkey = rdmab_lkey(req->rl_sendbuf);
-
-		req->rl_niovs = 4;
-	}
-
 	return 0;
 }
 
@@ -709,6 +716,37 @@ rpcrdma_connect_worker(struct work_struct *work)
 	spin_unlock_bh(&xprt->transport_lock);
 }
 
+#if defined(CONFIG_SUNRPC_BACKCHANNEL)
+/* 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
+rpcrdma_is_bcall(struct rpcrdma_msg *headerp)
+{
+	__be32 *p = (__be32 *)headerp;
+
+	if (headerp->rm_type != rdma_msg)
+		return false;
+	if (headerp->rm_body.rm_chunks[0] != xdr_zero)
+		return false;
+	if (headerp->rm_body.rm_chunks[1] != xdr_zero)
+		return false;
+	if (headerp->rm_body.rm_chunks[2] != xdr_zero)
+		return false;
+
+	/* sanity */
+	if (p[7] != headerp->rm_xid)
+		return false;
+	/* call direction */
+	if (p[8] != cpu_to_be32(RPC_CALL))
+		return false;
+
+	return true;
+}
+#endif	/* CONFIG_SUNRPC_BACKCHANNEL */
+
 /*
  * This function is called when an async event is posted to
  * the connection which changes the connection state. All it
@@ -721,8 +759,8 @@ rpcrdma_conn_func(struct rpcrdma_ep *ep)
 	schedule_delayed_work(&ep->rep_connect_worker, 0);
 }
 
-/*
- * Called as a tasklet to do req/reply match and complete a request
+/* Process received RPC/RDMA messages.
+ *
  * Errors must result in the RPC task either being awakened, or
  * allowed to timeout, to discover the errors at that time.
  */
@@ -732,60 +770,39 @@ rpcrdma_reply_handler(struct rpcrdma_rep *rep)
 	struct rpcrdma_msg *headerp;
 	struct rpcrdma_req *req;
 	struct rpc_rqst *rqst;
-	struct rpc_xprt *xprt = rep->rr_xprt;
-	struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
+	struct rpcrdma_xprt *r_xprt = rep->rr_rxprt;
+	struct rpc_xprt *xprt = &r_xprt->rx_xprt;
 	__be32 *iptr;
 	int rdmalen, status;
 	unsigned long cwnd;
 	u32 credits;
 
-	/* Check status. If bad, signal disconnect and return rep to pool */
-	if (rep->rr_len == ~0U) {
-		rpcrdma_recv_buffer_put(rep);
-		if (r_xprt->rx_ep.rep_connected == 1) {
-			r_xprt->rx_ep.rep_connected = -EIO;
-			rpcrdma_conn_func(&r_xprt->rx_ep);
-		}
-		return;
-	}
-	if (rep->rr_len < RPCRDMA_HDRLEN_MIN) {
-		dprintk("RPC:       %s: short/invalid reply\n", __func__);
-		goto repost;
-	}
+	dprintk("RPC:       %s: incoming rep %p\n", __func__, rep);
+
+	if (rep->rr_len == RPCRDMA_BAD_LEN)
+		goto out_badstatus;
+	if (rep->rr_len < RPCRDMA_HDRLEN_MIN)
+		goto out_shortreply;
+
 	headerp = rdmab_to_msg(rep->rr_rdmabuf);
-	if (headerp->rm_vers != rpcrdma_version) {
-		dprintk("RPC:       %s: invalid version %d\n",
-			__func__, be32_to_cpu(headerp->rm_vers));
-		goto repost;
-	}
+	if (headerp->rm_vers != rpcrdma_version)
+		goto out_badversion;
+#if defined(CONFIG_SUNRPC_BACKCHANNEL)
+	if (rpcrdma_is_bcall(headerp))
+		goto out_bcall;
+#endif
 
-	/* Get XID and try for a match. */
-	spin_lock(&xprt->transport_lock);
+	/* Match incoming rpcrdma_rep to an rpcrdma_req to
+	 * get context for handling any incoming chunks.
+	 */
+	spin_lock_bh(&xprt->transport_lock);
 	rqst = xprt_lookup_rqst(xprt, headerp->rm_xid);
-	if (rqst == NULL) {
-		spin_unlock(&xprt->transport_lock);
-		dprintk("RPC:       %s: reply 0x%p failed "
-			"to match any request xid 0x%08x len %d\n",
-			__func__, rep, be32_to_cpu(headerp->rm_xid),
-			rep->rr_len);
-repost:
-		r_xprt->rx_stats.bad_reply_count++;
-		rep->rr_func = rpcrdma_reply_handler;
-		if (rpcrdma_ep_post_recv(&r_xprt->rx_ia, &r_xprt->rx_ep, rep))
-			rpcrdma_recv_buffer_put(rep);
-
-		return;
-	}
+	if (!rqst)
+		goto out_nomatch;
 
-	/* get request object */
 	req = rpcr_to_rdmar(rqst);
-	if (req->rl_reply) {
-		spin_unlock(&xprt->transport_lock);
-		dprintk("RPC:       %s: duplicate reply 0x%p to RPC "
-			"request 0x%p: xid 0x%08x\n", __func__, rep, req,
-			be32_to_cpu(headerp->rm_xid));
-		goto repost;
-	}
+	if (req->rl_reply)
+		goto out_duplicate;
 
 	dprintk("RPC:       %s: reply 0x%p completes request 0x%p\n"
 		"                   RPC request 0x%p xid 0x%08x\n",
@@ -882,8 +899,50 @@ badheader:
 	if (xprt->cwnd > cwnd)
 		xprt_release_rqst_cong(rqst->rq_task);
 
+	xprt_complete_rqst(rqst->rq_task, status);
+	spin_unlock_bh(&xprt->transport_lock);
 	dprintk("RPC:       %s: xprt_complete_rqst(0x%p, 0x%p, %d)\n",
 			__func__, xprt, rqst, status);
-	xprt_complete_rqst(rqst->rq_task, status);
-	spin_unlock(&xprt->transport_lock);
+	return;
+
+out_badstatus:
+	rpcrdma_recv_buffer_put(rep);
+	if (r_xprt->rx_ep.rep_connected == 1) {
+		r_xprt->rx_ep.rep_connected = -EIO;
+		rpcrdma_conn_func(&r_xprt->rx_ep);
+	}
+	return;
+
+#if defined(CONFIG_SUNRPC_BACKCHANNEL)
+out_bcall:
+	rpcrdma_bc_receive_call(r_xprt, rep);
+	return;
+#endif
+
+out_shortreply:
+	dprintk("RPC:       %s: short/invalid reply\n", __func__);
+	goto repost;
+
+out_badversion:
+	dprintk("RPC:       %s: invalid version %d\n",
+		__func__, be32_to_cpu(headerp->rm_vers));
+	goto repost;
+
+out_nomatch:
+	spin_unlock_bh(&xprt->transport_lock);
+	dprintk("RPC:       %s: no match for incoming xid 0x%08x len %d\n",
+		__func__, be32_to_cpu(headerp->rm_xid),
+		rep->rr_len);
+	goto repost;
+
+out_duplicate:
+	spin_unlock_bh(&xprt->transport_lock);
+	dprintk("RPC:       %s: "
+		"duplicate reply %p to RPC request %p: xid 0x%08x\n",
+		__func__, rep, req, be32_to_cpu(headerp->rm_xid));
+
+repost:
+	r_xprt->rx_stats.bad_reply_count++;
+	if (rpcrdma_ep_post_recv(&r_xprt->rx_ia, &r_xprt->rx_ep, rep))
+		rpcrdma_recv_buffer_put(rep);
 }
diff --git a/kernel/net/sunrpc/xprtrdma/svc_rdma.c b/kernel/net/sunrpc/xprtrdma/svc_rdma.c
index c1b627026..1b7051bdb 100644
--- a/kernel/net/sunrpc/xprtrdma/svc_rdma.c
+++ b/kernel/net/sunrpc/xprtrdma/svc_rdma.c
@@ -38,8 +38,7 @@
  *
  * Author: Tom Tucker <tom@opengridcomputing.com>
  */
-#include <linux/module.h>
-#include <linux/init.h>
+
 #include <linux/slab.h>
 #include <linux/fs.h>
 #include <linux/sysctl.h>
@@ -240,6 +239,9 @@ void svc_rdma_cleanup(void)
 		unregister_sysctl_table(svcrdma_table_header);
 		svcrdma_table_header = NULL;
 	}
+#if defined(CONFIG_SUNRPC_BACKCHANNEL)
+	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);
@@ -287,6 +289,9 @@ int svc_rdma_init(void)
 
 	/* 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);
@@ -295,8 +300,3 @@ int svc_rdma_init(void)
 	destroy_workqueue(svc_rdma_wq);
 	return -ENOMEM;
 }
-MODULE_AUTHOR("Tom Tucker <tom@opengridcomputing.com>");
-MODULE_DESCRIPTION("SVC RDMA Transport");
-MODULE_LICENSE("Dual BSD/GPL");
-module_init(svc_rdma_init);
-module_exit(svc_rdma_cleanup);
diff --git a/kernel/net/sunrpc/xprtrdma/svc_rdma_marshal.c b/kernel/net/sunrpc/xprtrdma/svc_rdma_marshal.c
index b681855cf..e2fca7617 100644
--- a/kernel/net/sunrpc/xprtrdma/svc_rdma_marshal.c
+++ b/kernel/net/sunrpc/xprtrdma/svc_rdma_marshal.c
@@ -50,12 +50,12 @@
 /*
  * Decodes a read chunk list. The expected format is as follows:
  *    descrim  : xdr_one
- *    position : u32 offset into XDR stream
- *    handle   : u32 RKEY
+ *    position : __be32 offset into XDR stream
+ *    handle   : __be32 RKEY
  *    . . .
  *  end-of-list: xdr_zero
  */
-static u32 *decode_read_list(u32 *va, u32 *vaend)
+static __be32 *decode_read_list(__be32 *va, __be32 *vaend)
 {
 	struct rpcrdma_read_chunk *ch = (struct rpcrdma_read_chunk *)va;
 
@@ -67,20 +67,20 @@ static u32 *decode_read_list(u32 *va, u32 *vaend)
 		}
 		ch++;
 	}
-	return (u32 *)&ch->rc_position;
+	return &ch->rc_position;
 }
 
 /*
  * Decodes a write chunk list. The expected format is as follows:
  *    descrim  : xdr_one
  *    nchunks  : <count>
- *       handle   : u32 RKEY              ---+
- *       length   : u32 <len of segment>     |
+ *       handle   : __be32 RKEY           ---+
+ *       length   : __be32 <len of segment>  |
  *       offset   : remove va                + <count>
  *       . . .                               |
  *                                        ---+
  */
-static u32 *decode_write_list(u32 *va, u32 *vaend)
+static __be32 *decode_write_list(__be32 *va, __be32 *vaend)
 {
 	unsigned long start, end;
 	int nchunks;
@@ -90,14 +90,14 @@ static u32 *decode_write_list(u32 *va, u32 *vaend)
 
 	/* Check for not write-array */
 	if (ary->wc_discrim == xdr_zero)
-		return (u32 *)&ary->wc_nchunks;
+		return &ary->wc_nchunks;
 
 	if ((unsigned long)ary + sizeof(struct rpcrdma_write_array) >
 	    (unsigned long)vaend) {
 		dprintk("svcrdma: ary=%p, vaend=%p\n", ary, vaend);
 		return NULL;
 	}
-	nchunks = ntohl(ary->wc_nchunks);
+	nchunks = be32_to_cpu(ary->wc_nchunks);
 
 	start = (unsigned long)&ary->wc_array[0];
 	end = (unsigned long)vaend;
@@ -112,10 +112,10 @@ static u32 *decode_write_list(u32 *va, u32 *vaend)
 	 * rs_length is the 2nd 4B field in wc_target and taking its
 	 * address skips the list terminator
 	 */
-	return (u32 *)&ary->wc_array[nchunks].wc_target.rs_length;
+	return &ary->wc_array[nchunks].wc_target.rs_length;
 }
 
-static u32 *decode_reply_array(u32 *va, u32 *vaend)
+static __be32 *decode_reply_array(__be32 *va, __be32 *vaend)
 {
 	unsigned long start, end;
 	int nchunks;
@@ -124,14 +124,14 @@ static u32 *decode_reply_array(u32 *va, u32 *vaend)
 
 	/* Check for no reply-array */
 	if (ary->wc_discrim == xdr_zero)
-		return (u32 *)&ary->wc_nchunks;
+		return &ary->wc_nchunks;
 
 	if ((unsigned long)ary + sizeof(struct rpcrdma_write_array) >
 	    (unsigned long)vaend) {
 		dprintk("svcrdma: ary=%p, vaend=%p\n", ary, vaend);
 		return NULL;
 	}
-	nchunks = ntohl(ary->wc_nchunks);
+	nchunks = be32_to_cpu(ary->wc_nchunks);
 
 	start = (unsigned long)&ary->wc_array[0];
 	end = (unsigned long)vaend;
@@ -142,15 +142,14 @@ static u32 *decode_reply_array(u32 *va, u32 *vaend)
 			ary, nchunks, vaend);
 		return NULL;
 	}
-	return (u32 *)&ary->wc_array[nchunks];
+	return (__be32 *)&ary->wc_array[nchunks];
 }
 
 int svc_rdma_xdr_decode_req(struct rpcrdma_msg **rdma_req,
 			    struct svc_rqst *rqstp)
 {
 	struct rpcrdma_msg *rmsgp = NULL;
-	u32 *va;
-	u32 *vaend;
+	__be32 *va, *vaend;
 	u32 hdr_len;
 
 	rmsgp = (struct rpcrdma_msg *)rqstp->rq_arg.head[0].iov_base;
@@ -162,22 +161,17 @@ int svc_rdma_xdr_decode_req(struct rpcrdma_msg **rdma_req,
 		return -EINVAL;
 	}
 
-	/* Decode the header */
-	rmsgp->rm_xid = ntohl(rmsgp->rm_xid);
-	rmsgp->rm_vers = ntohl(rmsgp->rm_vers);
-	rmsgp->rm_credit = ntohl(rmsgp->rm_credit);
-	rmsgp->rm_type = ntohl(rmsgp->rm_type);
-
-	if (rmsgp->rm_vers != RPCRDMA_VERSION)
+	if (rmsgp->rm_vers != rpcrdma_version)
 		return -ENOSYS;
 
 	/* Pull in the extra for the padded case and bump our pointer */
-	if (rmsgp->rm_type == RDMA_MSGP) {
+	if (rmsgp->rm_type == rdma_msgp) {
 		int hdrlen;
+
 		rmsgp->rm_body.rm_padded.rm_align =
-			ntohl(rmsgp->rm_body.rm_padded.rm_align);
+			be32_to_cpu(rmsgp->rm_body.rm_padded.rm_align);
 		rmsgp->rm_body.rm_padded.rm_thresh =
-			ntohl(rmsgp->rm_body.rm_padded.rm_thresh);
+			be32_to_cpu(rmsgp->rm_body.rm_padded.rm_thresh);
 
 		va = &rmsgp->rm_body.rm_padded.rm_pempty[4];
 		rqstp->rq_arg.head[0].iov_base = va;
@@ -192,7 +186,7 @@ int svc_rdma_xdr_decode_req(struct rpcrdma_msg **rdma_req,
 	 * chunk list and a reply chunk list.
 	 */
 	va = &rmsgp->rm_body.rm_chunks[0];
-	vaend = (u32 *)((unsigned long)rmsgp + rqstp->rq_arg.len);
+	vaend = (__be32 *)((unsigned long)rmsgp + rqstp->rq_arg.len);
 	va = decode_read_list(va, vaend);
 	if (!va)
 		return -EINVAL;
@@ -211,76 +205,20 @@ int svc_rdma_xdr_decode_req(struct rpcrdma_msg **rdma_req,
 	return hdr_len;
 }
 
-int svc_rdma_xdr_decode_deferred_req(struct svc_rqst *rqstp)
-{
-	struct rpcrdma_msg *rmsgp = NULL;
-	struct rpcrdma_read_chunk *ch;
-	struct rpcrdma_write_array *ary;
-	u32 *va;
-	u32 hdrlen;
-
-	dprintk("svcrdma: processing deferred RDMA header on rqstp=%p\n",
-		rqstp);
-	rmsgp = (struct rpcrdma_msg *)rqstp->rq_arg.head[0].iov_base;
-
-	/* Pull in the extra for the padded case and bump our pointer */
-	if (rmsgp->rm_type == RDMA_MSGP) {
-		va = &rmsgp->rm_body.rm_padded.rm_pempty[4];
-		rqstp->rq_arg.head[0].iov_base = va;
-		hdrlen = (u32)((unsigned long)va - (unsigned long)rmsgp);
-		rqstp->rq_arg.head[0].iov_len -= hdrlen;
-		return hdrlen;
-	}
-
-	/*
-	 * Skip all chunks to find RPC msg. These were previously processed
-	 */
-	va = &rmsgp->rm_body.rm_chunks[0];
-
-	/* Skip read-list */
-	for (ch = (struct rpcrdma_read_chunk *)va;
-	     ch->rc_discrim != xdr_zero; ch++);
-	va = (u32 *)&ch->rc_position;
-
-	/* Skip write-list */
-	ary = (struct rpcrdma_write_array *)va;
-	if (ary->wc_discrim == xdr_zero)
-		va = (u32 *)&ary->wc_nchunks;
-	else
-		/*
-		 * rs_length is the 2nd 4B field in wc_target and taking its
-		 * address skips the list terminator
-		 */
-		va = (u32 *)&ary->wc_array[ary->wc_nchunks].wc_target.rs_length;
-
-	/* Skip reply-array */
-	ary = (struct rpcrdma_write_array *)va;
-	if (ary->wc_discrim == xdr_zero)
-		va = (u32 *)&ary->wc_nchunks;
-	else
-		va = (u32 *)&ary->wc_array[ary->wc_nchunks];
-
-	rqstp->rq_arg.head[0].iov_base = va;
-	hdrlen = (unsigned long)va - (unsigned long)rmsgp;
-	rqstp->rq_arg.head[0].iov_len -= hdrlen;
-
-	return hdrlen;
-}
-
 int svc_rdma_xdr_encode_error(struct svcxprt_rdma *xprt,
 			      struct rpcrdma_msg *rmsgp,
-			      enum rpcrdma_errcode err, u32 *va)
+			      enum rpcrdma_errcode err, __be32 *va)
 {
-	u32 *startp = va;
+	__be32 *startp = va;
 
-	*va++ = htonl(rmsgp->rm_xid);
-	*va++ = htonl(rmsgp->rm_vers);
-	*va++ = htonl(xprt->sc_max_requests);
-	*va++ = htonl(RDMA_ERROR);
-	*va++ = htonl(err);
+	*va++ = rmsgp->rm_xid;
+	*va++ = rmsgp->rm_vers;
+	*va++ = cpu_to_be32(xprt->sc_max_requests);
+	*va++ = rdma_error;
+	*va++ = cpu_to_be32(err);
 	if (err == ERR_VERS) {
-		*va++ = htonl(RPCRDMA_VERSION);
-		*va++ = htonl(RPCRDMA_VERSION);
+		*va++ = rpcrdma_version;
+		*va++ = rpcrdma_version;
 	}
 
 	return (int)((unsigned long)va - (unsigned long)startp);
@@ -297,7 +235,7 @@ int svc_rdma_xdr_get_reply_hdr_len(struct rpcrdma_msg *rmsgp)
 		&rmsgp->rm_body.rm_chunks[1];
 	if (wr_ary->wc_discrim)
 		wr_ary = (struct rpcrdma_write_array *)
-			&wr_ary->wc_array[ntohl(wr_ary->wc_nchunks)].
+			&wr_ary->wc_array[be32_to_cpu(wr_ary->wc_nchunks)].
 			wc_target.rs_length;
 	else
 		wr_ary = (struct rpcrdma_write_array *)
@@ -306,7 +244,7 @@ int svc_rdma_xdr_get_reply_hdr_len(struct rpcrdma_msg *rmsgp)
 	/* skip reply array */
 	if (wr_ary->wc_discrim)
 		wr_ary = (struct rpcrdma_write_array *)
-			&wr_ary->wc_array[ntohl(wr_ary->wc_nchunks)];
+			&wr_ary->wc_array[be32_to_cpu(wr_ary->wc_nchunks)];
 	else
 		wr_ary = (struct rpcrdma_write_array *)
 			&wr_ary->wc_nchunks;
@@ -325,7 +263,7 @@ void svc_rdma_xdr_encode_write_list(struct rpcrdma_msg *rmsgp, int chunks)
 	ary = (struct rpcrdma_write_array *)
 		&rmsgp->rm_body.rm_chunks[1];
 	ary->wc_discrim = xdr_one;
-	ary->wc_nchunks = htonl(chunks);
+	ary->wc_nchunks = cpu_to_be32(chunks);
 
 	/* write-list terminator */
 	ary->wc_array[chunks].wc_target.rs_handle = xdr_zero;
@@ -338,7 +276,7 @@ void svc_rdma_xdr_encode_reply_array(struct rpcrdma_write_array *ary,
 				 int chunks)
 {
 	ary->wc_discrim = xdr_one;
-	ary->wc_nchunks = htonl(chunks);
+	ary->wc_nchunks = cpu_to_be32(chunks);
 }
 
 void svc_rdma_xdr_encode_array_chunk(struct rpcrdma_write_array *ary,
@@ -350,7 +288,7 @@ void svc_rdma_xdr_encode_array_chunk(struct rpcrdma_write_array *ary,
 	struct rpcrdma_segment *seg = &ary->wc_array[chunk_no].wc_target;
 	seg->rs_handle = rs_handle;
 	seg->rs_offset = rs_offset;
-	seg->rs_length = htonl(write_len);
+	seg->rs_length = cpu_to_be32(write_len);
 }
 
 void svc_rdma_xdr_encode_reply_header(struct svcxprt_rdma *xprt,
@@ -358,10 +296,10 @@ void svc_rdma_xdr_encode_reply_header(struct svcxprt_rdma *xprt,
 				  struct rpcrdma_msg *rdma_resp,
 				  enum rpcrdma_proc rdma_type)
 {
-	rdma_resp->rm_xid = htonl(rdma_argp->rm_xid);
-	rdma_resp->rm_vers = htonl(rdma_argp->rm_vers);
-	rdma_resp->rm_credit = htonl(xprt->sc_max_requests);
-	rdma_resp->rm_type = htonl(rdma_type);
+	rdma_resp->rm_xid = rdma_argp->rm_xid;
+	rdma_resp->rm_vers = rdma_argp->rm_vers;
+	rdma_resp->rm_credit = cpu_to_be32(xprt->sc_max_requests);
+	rdma_resp->rm_type = cpu_to_be32(rdma_type);
 
 	/* Encode <nul> chunks lists */
 	rdma_resp->rm_body.rm_chunks[0] = xdr_zero;
diff --git a/kernel/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c b/kernel/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
index f9f13a32d..ff4f01e52 100644
--- a/kernel/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
+++ b/kernel/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
@@ -85,7 +85,7 @@ static void rdma_build_arg_xdr(struct svc_rqst *rqstp,
 
 	/* RDMA_NOMSG: RDMA READ data should land just after RDMA RECV data */
 	rmsgp = (struct rpcrdma_msg *)rqstp->rq_arg.head[0].iov_base;
-	if (be32_to_cpu(rmsgp->rm_type) == RDMA_NOMSG)
+	if (rmsgp->rm_type == rdma_nomsg)
 		rqstp->rq_arg.pages = &rqstp->rq_pages[0];
 	else
 		rqstp->rq_arg.pages = &rqstp->rq_pages[1];
@@ -115,15 +115,6 @@ static void rdma_build_arg_xdr(struct svc_rqst *rqstp,
 	rqstp->rq_arg.tail[0].iov_len = 0;
 }
 
-static int rdma_read_max_sge(struct svcxprt_rdma *xprt, int sge_count)
-{
-	if (rdma_node_get_transport(xprt->sc_cm_id->device->node_type) ==
-	     RDMA_TRANSPORT_IWARP)
-		return 1;
-	else
-		return min_t(int, sge_count, xprt->sc_max_sge);
-}
-
 /* Issue an RDMA_READ using the local lkey to map the data sink */
 int rdma_read_chunk_lcl(struct svcxprt_rdma *xprt,
 			struct svc_rqst *rqstp,
@@ -135,7 +126,7 @@ int rdma_read_chunk_lcl(struct svcxprt_rdma *xprt,
 			u64 rs_offset,
 			bool last)
 {
-	struct ib_send_wr read_wr;
+	struct ib_rdma_wr read_wr;
 	int pages_needed = PAGE_ALIGN(*page_offset + rs_length) >> PAGE_SHIFT;
 	struct svc_rdma_op_ctxt *ctxt = svc_rdma_get_context(xprt);
 	int ret, read, pno;
@@ -144,9 +135,9 @@ int rdma_read_chunk_lcl(struct svcxprt_rdma *xprt,
 
 	ctxt->direction = DMA_FROM_DEVICE;
 	ctxt->read_hdr = head;
-	pages_needed =
-		min_t(int, pages_needed, rdma_read_max_sge(xprt, pages_needed));
-	read = min_t(int, pages_needed << PAGE_SHIFT, rs_length);
+	pages_needed = min_t(int, pages_needed, xprt->sc_max_sge_rd);
+	read = min_t(int, (pages_needed << PAGE_SHIFT) - *page_offset,
+		     rs_length);
 
 	for (pno = 0; pno < pages_needed; pno++) {
 		int len = min_t(int, rs_length, PAGE_SIZE - pg_off);
@@ -189,16 +180,16 @@ int rdma_read_chunk_lcl(struct svcxprt_rdma *xprt,
 		clear_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags);
 
 	memset(&read_wr, 0, sizeof(read_wr));
-	read_wr.wr_id = (unsigned long)ctxt;
-	read_wr.opcode = IB_WR_RDMA_READ;
-	ctxt->wr_op = read_wr.opcode;
-	read_wr.send_flags = IB_SEND_SIGNALED;
-	read_wr.wr.rdma.rkey = rs_handle;
-	read_wr.wr.rdma.remote_addr = rs_offset;
-	read_wr.sg_list = ctxt->sge;
-	read_wr.num_sge = pages_needed;
-
-	ret = svc_rdma_send(xprt, &read_wr);
+	read_wr.wr.wr_id = (unsigned long)ctxt;
+	read_wr.wr.opcode = IB_WR_RDMA_READ;
+	ctxt->wr_op = read_wr.wr.opcode;
+	read_wr.wr.send_flags = IB_SEND_SIGNALED;
+	read_wr.rkey = rs_handle;
+	read_wr.remote_addr = rs_offset;
+	read_wr.wr.sg_list = ctxt->sge;
+	read_wr.wr.num_sge = pages_needed;
+
+	ret = svc_rdma_send(xprt, &read_wr.wr);
 	if (ret) {
 		pr_err("svcrdma: Error %d posting RDMA_READ\n", ret);
 		set_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags);
@@ -228,14 +219,14 @@ int rdma_read_chunk_frmr(struct svcxprt_rdma *xprt,
 			 u64 rs_offset,
 			 bool last)
 {
-	struct ib_send_wr read_wr;
+	struct ib_rdma_wr read_wr;
 	struct ib_send_wr inv_wr;
-	struct ib_send_wr fastreg_wr;
+	struct ib_reg_wr reg_wr;
 	u8 key;
-	int pages_needed = PAGE_ALIGN(*page_offset + rs_length) >> PAGE_SHIFT;
+	int nents = PAGE_ALIGN(*page_offset + rs_length) >> PAGE_SHIFT;
 	struct svc_rdma_op_ctxt *ctxt = svc_rdma_get_context(xprt);
 	struct svc_rdma_fastreg_mr *frmr = svc_rdma_get_frmr(xprt);
-	int ret, read, pno;
+	int ret, read, pno, dma_nents, n;
 	u32 pg_off = *page_offset;
 	u32 pg_no = *page_no;
 
@@ -244,16 +235,14 @@ int rdma_read_chunk_frmr(struct svcxprt_rdma *xprt,
 
 	ctxt->direction = DMA_FROM_DEVICE;
 	ctxt->frmr = frmr;
-	pages_needed = min_t(int, pages_needed, xprt->sc_frmr_pg_list_len);
-	read = min_t(int, pages_needed << PAGE_SHIFT, rs_length);
+	nents = min_t(unsigned int, nents, xprt->sc_frmr_pg_list_len);
+	read = min_t(int, (nents << PAGE_SHIFT) - *page_offset, rs_length);
 
-	frmr->kva = page_address(rqstp->rq_arg.pages[pg_no]);
 	frmr->direction = DMA_FROM_DEVICE;
 	frmr->access_flags = (IB_ACCESS_LOCAL_WRITE|IB_ACCESS_REMOTE_WRITE);
-	frmr->map_len = pages_needed << PAGE_SHIFT;
-	frmr->page_list_len = pages_needed;
+	frmr->sg_nents = nents;
 
-	for (pno = 0; pno < pages_needed; pno++) {
+	for (pno = 0; pno < nents; pno++) {
 		int len = min_t(int, rs_length, PAGE_SIZE - pg_off);
 
 		head->arg.pages[pg_no] = rqstp->rq_arg.pages[pg_no];
@@ -261,17 +250,12 @@ int rdma_read_chunk_frmr(struct svcxprt_rdma *xprt,
 		head->arg.len += len;
 		if (!pg_off)
 			head->count++;
+
+		sg_set_page(&frmr->sg[pno], rqstp->rq_arg.pages[pg_no],
+			    len, pg_off);
+
 		rqstp->rq_respages = &rqstp->rq_arg.pages[pg_no+1];
 		rqstp->rq_next_page = rqstp->rq_respages + 1;
-		frmr->page_list->page_list[pno] =
-			ib_dma_map_page(xprt->sc_cm_id->device,
-					head->arg.pages[pg_no], 0,
-					PAGE_SIZE, DMA_FROM_DEVICE);
-		ret = ib_dma_mapping_error(xprt->sc_cm_id->device,
-					   frmr->page_list->page_list[pno]);
-		if (ret)
-			goto err;
-		atomic_inc(&xprt->sc_dma_used);
 
 		/* adjust offset and wrap to next page if needed */
 		pg_off += len;
@@ -287,43 +271,57 @@ int rdma_read_chunk_frmr(struct svcxprt_rdma *xprt,
 	else
 		clear_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags);
 
+	dma_nents = ib_dma_map_sg(xprt->sc_cm_id->device,
+				  frmr->sg, frmr->sg_nents,
+				  frmr->direction);
+	if (!dma_nents) {
+		pr_err("svcrdma: failed to dma map sg %p\n",
+		       frmr->sg);
+		return -ENOMEM;
+	}
+	atomic_inc(&xprt->sc_dma_used);
+
+	n = ib_map_mr_sg(frmr->mr, frmr->sg, frmr->sg_nents, PAGE_SIZE);
+	if (unlikely(n != frmr->sg_nents)) {
+		pr_err("svcrdma: failed to map mr %p (%d/%d elements)\n",
+		       frmr->mr, n, frmr->sg_nents);
+		return n < 0 ? n : -EINVAL;
+	}
+
 	/* Bump the key */
 	key = (u8)(frmr->mr->lkey & 0x000000FF);
 	ib_update_fast_reg_key(frmr->mr, ++key);
 
-	ctxt->sge[0].addr = (unsigned long)frmr->kva + *page_offset;
+	ctxt->sge[0].addr = frmr->mr->iova;
 	ctxt->sge[0].lkey = frmr->mr->lkey;
-	ctxt->sge[0].length = read;
+	ctxt->sge[0].length = frmr->mr->length;
 	ctxt->count = 1;
 	ctxt->read_hdr = head;
 
-	/* Prepare FASTREG WR */
-	memset(&fastreg_wr, 0, sizeof(fastreg_wr));
-	fastreg_wr.opcode = IB_WR_FAST_REG_MR;
-	fastreg_wr.send_flags = IB_SEND_SIGNALED;
-	fastreg_wr.wr.fast_reg.iova_start = (unsigned long)frmr->kva;
-	fastreg_wr.wr.fast_reg.page_list = frmr->page_list;
-	fastreg_wr.wr.fast_reg.page_list_len = frmr->page_list_len;
-	fastreg_wr.wr.fast_reg.page_shift = PAGE_SHIFT;
-	fastreg_wr.wr.fast_reg.length = frmr->map_len;
-	fastreg_wr.wr.fast_reg.access_flags = frmr->access_flags;
-	fastreg_wr.wr.fast_reg.rkey = frmr->mr->lkey;
-	fastreg_wr.next = &read_wr;
+	/* Prepare REG WR */
+	reg_wr.wr.opcode = IB_WR_REG_MR;
+	reg_wr.wr.wr_id = 0;
+	reg_wr.wr.send_flags = IB_SEND_SIGNALED;
+	reg_wr.wr.num_sge = 0;
+	reg_wr.mr = frmr->mr;
+	reg_wr.key = frmr->mr->lkey;
+	reg_wr.access = frmr->access_flags;
+	reg_wr.wr.next = &read_wr.wr;
 
 	/* Prepare RDMA_READ */
 	memset(&read_wr, 0, sizeof(read_wr));
-	read_wr.send_flags = IB_SEND_SIGNALED;
-	read_wr.wr.rdma.rkey = rs_handle;
-	read_wr.wr.rdma.remote_addr = rs_offset;
-	read_wr.sg_list = ctxt->sge;
-	read_wr.num_sge = 1;
+	read_wr.wr.send_flags = IB_SEND_SIGNALED;
+	read_wr.rkey = rs_handle;
+	read_wr.remote_addr = rs_offset;
+	read_wr.wr.sg_list = ctxt->sge;
+	read_wr.wr.num_sge = 1;
 	if (xprt->sc_dev_caps & SVCRDMA_DEVCAP_READ_W_INV) {
-		read_wr.opcode = IB_WR_RDMA_READ_WITH_INV;
-		read_wr.wr_id = (unsigned long)ctxt;
-		read_wr.ex.invalidate_rkey = ctxt->frmr->mr->lkey;
+		read_wr.wr.opcode = IB_WR_RDMA_READ_WITH_INV;
+		read_wr.wr.wr_id = (unsigned long)ctxt;
+		read_wr.wr.ex.invalidate_rkey = ctxt->frmr->mr->lkey;
 	} else {
-		read_wr.opcode = IB_WR_RDMA_READ;
-		read_wr.next = &inv_wr;
+		read_wr.wr.opcode = IB_WR_RDMA_READ;
+		read_wr.wr.next = &inv_wr;
 		/* Prepare invalidate */
 		memset(&inv_wr, 0, sizeof(inv_wr));
 		inv_wr.wr_id = (unsigned long)ctxt;
@@ -331,10 +329,10 @@ int rdma_read_chunk_frmr(struct svcxprt_rdma *xprt,
 		inv_wr.send_flags = IB_SEND_SIGNALED | IB_SEND_FENCE;
 		inv_wr.ex.invalidate_rkey = frmr->mr->lkey;
 	}
-	ctxt->wr_op = read_wr.opcode;
+	ctxt->wr_op = read_wr.wr.opcode;
 
 	/* Post the chain */
-	ret = svc_rdma_send(xprt, &fastreg_wr);
+	ret = svc_rdma_send(xprt, &reg_wr.wr);
 	if (ret) {
 		pr_err("svcrdma: Error %d posting RDMA_READ\n", ret);
 		set_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags);
@@ -348,7 +346,8 @@ int rdma_read_chunk_frmr(struct svcxprt_rdma *xprt,
 	atomic_inc(&rdma_stat_read);
 	return ret;
  err:
-	svc_rdma_unmap_dma(ctxt);
+	ib_dma_unmap_sg(xprt->sc_cm_id->device,
+			frmr->sg, frmr->sg_nents, frmr->direction);
 	svc_rdma_put_context(ctxt, 0);
 	svc_rdma_put_frmr(xprt, frmr);
 	return ret;
@@ -541,7 +540,7 @@ static int rdma_read_complete(struct svc_rqst *rqstp,
 	rqstp->rq_arg.page_base = head->arg.page_base;
 
 	/* rq_respages starts after the last arg page */
-	rqstp->rq_respages = &rqstp->rq_arg.pages[page_no];
+	rqstp->rq_respages = &rqstp->rq_pages[page_no];
 	rqstp->rq_next_page = rqstp->rq_respages + 1;
 
 	/* Rebuild rq_arg head and tail. */
diff --git a/kernel/net/sunrpc/xprtrdma/svc_rdma_sendto.c b/kernel/net/sunrpc/xprtrdma/svc_rdma_sendto.c
index 7de33d1af..969a1ab75 100644
--- a/kernel/net/sunrpc/xprtrdma/svc_rdma_sendto.c
+++ b/kernel/net/sunrpc/xprtrdma/svc_rdma_sendto.c
@@ -136,6 +136,79 @@ static dma_addr_t dma_map_xdr(struct svcxprt_rdma *xprt,
 	return dma_addr;
 }
 
+/* Returns the address of the first read chunk or <nul> if no read chunk
+ * is present
+ */
+struct rpcrdma_read_chunk *
+svc_rdma_get_read_chunk(struct rpcrdma_msg *rmsgp)
+{
+	struct rpcrdma_read_chunk *ch =
+		(struct rpcrdma_read_chunk *)&rmsgp->rm_body.rm_chunks[0];
+
+	if (ch->rc_discrim == xdr_zero)
+		return NULL;
+	return ch;
+}
+
+/* Returns the address of the first read write array element or <nul>
+ * if no write array list is present
+ */
+static struct rpcrdma_write_array *
+svc_rdma_get_write_array(struct rpcrdma_msg *rmsgp)
+{
+	if (rmsgp->rm_body.rm_chunks[0] != xdr_zero ||
+	    rmsgp->rm_body.rm_chunks[1] == xdr_zero)
+		return NULL;
+	return (struct rpcrdma_write_array *)&rmsgp->rm_body.rm_chunks[1];
+}
+
+/* Returns the address of the first reply array element or <nul> if no
+ * reply array is present
+ */
+static struct rpcrdma_write_array *
+svc_rdma_get_reply_array(struct rpcrdma_msg *rmsgp)
+{
+	struct rpcrdma_read_chunk *rch;
+	struct rpcrdma_write_array *wr_ary;
+	struct rpcrdma_write_array *rp_ary;
+
+	/* XXX: Need to fix when reply chunk may occur with read list
+	 *	and/or write list.
+	 */
+	if (rmsgp->rm_body.rm_chunks[0] != xdr_zero ||
+	    rmsgp->rm_body.rm_chunks[1] != xdr_zero)
+		return NULL;
+
+	rch = svc_rdma_get_read_chunk(rmsgp);
+	if (rch) {
+		while (rch->rc_discrim != xdr_zero)
+			rch++;
+
+		/* The reply chunk follows an empty write array located
+		 * at 'rc_position' here. The reply array is at rc_target.
+		 */
+		rp_ary = (struct rpcrdma_write_array *)&rch->rc_target;
+		goto found_it;
+	}
+
+	wr_ary = svc_rdma_get_write_array(rmsgp);
+	if (wr_ary) {
+		int chunk = be32_to_cpu(wr_ary->wc_nchunks);
+
+		rp_ary = (struct rpcrdma_write_array *)
+			 &wr_ary->wc_array[chunk].wc_target.rs_length;
+		goto found_it;
+	}
+
+	/* No read list, no write list */
+	rp_ary = (struct rpcrdma_write_array *)&rmsgp->rm_body.rm_chunks[2];
+
+ found_it:
+	if (rp_ary->wc_discrim == xdr_zero)
+		return NULL;
+	return rp_ary;
+}
+
 /* Assumptions:
  * - The specified write_len can be represented in sc_max_sge * PAGE_SIZE
  */
@@ -144,7 +217,7 @@ static int send_write(struct svcxprt_rdma *xprt, struct svc_rqst *rqstp,
 		      u32 xdr_off, int write_len,
 		      struct svc_rdma_req_map *vec)
 {
-	struct ib_send_wr write_wr;
+	struct ib_rdma_wr write_wr;
 	struct ib_sge *sge;
 	int xdr_sge_no;
 	int sge_no;
@@ -209,17 +282,17 @@ static int send_write(struct svcxprt_rdma *xprt, struct svc_rqst *rqstp,
 	/* Prepare WRITE WR */
 	memset(&write_wr, 0, sizeof write_wr);
 	ctxt->wr_op = IB_WR_RDMA_WRITE;
-	write_wr.wr_id = (unsigned long)ctxt;
-	write_wr.sg_list = &sge[0];
-	write_wr.num_sge = sge_no;
-	write_wr.opcode = IB_WR_RDMA_WRITE;
-	write_wr.send_flags = IB_SEND_SIGNALED;
-	write_wr.wr.rdma.rkey = rmr;
-	write_wr.wr.rdma.remote_addr = to;
+	write_wr.wr.wr_id = (unsigned long)ctxt;
+	write_wr.wr.sg_list = &sge[0];
+	write_wr.wr.num_sge = sge_no;
+	write_wr.wr.opcode = IB_WR_RDMA_WRITE;
+	write_wr.wr.send_flags = IB_SEND_SIGNALED;
+	write_wr.rkey = rmr;
+	write_wr.remote_addr = to;
 
 	/* Post It */
 	atomic_inc(&rdma_stat_write);
-	if (svc_rdma_send(xprt, &write_wr))
+	if (svc_rdma_send(xprt, &write_wr.wr))
 		goto err;
 	return write_len - bc;
  err:
@@ -240,6 +313,7 @@ static int send_write_chunks(struct svcxprt_rdma *xprt,
 	u32 xdr_off;
 	int chunk_off;
 	int chunk_no;
+	int nchunks;
 	struct rpcrdma_write_array *arg_ary;
 	struct rpcrdma_write_array *res_ary;
 	int ret;
@@ -251,14 +325,15 @@ static int send_write_chunks(struct svcxprt_rdma *xprt,
 		&rdma_resp->rm_body.rm_chunks[1];
 
 	/* Write chunks start at the pagelist */
+	nchunks = be32_to_cpu(arg_ary->wc_nchunks);
 	for (xdr_off = rqstp->rq_res.head[0].iov_len, chunk_no = 0;
-	     xfer_len && chunk_no < arg_ary->wc_nchunks;
+	     xfer_len && chunk_no < nchunks;
 	     chunk_no++) {
 		struct rpcrdma_segment *arg_ch;
 		u64 rs_offset;
 
 		arg_ch = &arg_ary->wc_array[chunk_no].wc_target;
-		write_len = min(xfer_len, ntohl(arg_ch->rs_length));
+		write_len = min(xfer_len, be32_to_cpu(arg_ch->rs_length));
 
 		/* Prepare the response chunk given the length actually
 		 * written */
@@ -270,7 +345,7 @@ static int send_write_chunks(struct svcxprt_rdma *xprt,
 		chunk_off = 0;
 		while (write_len) {
 			ret = send_write(xprt, rqstp,
-					 ntohl(arg_ch->rs_handle),
+					 be32_to_cpu(arg_ch->rs_handle),
 					 rs_offset + chunk_off,
 					 xdr_off,
 					 write_len,
@@ -318,13 +393,13 @@ static int send_reply_chunks(struct svcxprt_rdma *xprt,
 		&rdma_resp->rm_body.rm_chunks[2];
 
 	/* xdr offset starts at RPC message */
-	nchunks = ntohl(arg_ary->wc_nchunks);
+	nchunks = be32_to_cpu(arg_ary->wc_nchunks);
 	for (xdr_off = 0, chunk_no = 0;
 	     xfer_len && chunk_no < nchunks;
 	     chunk_no++) {
 		u64 rs_offset;
 		ch = &arg_ary->wc_array[chunk_no].wc_target;
-		write_len = min(xfer_len, htonl(ch->rs_length));
+		write_len = min(xfer_len, be32_to_cpu(ch->rs_length));
 
 		/* Prepare the reply chunk given the length actually
 		 * written */
@@ -335,7 +410,7 @@ static int send_reply_chunks(struct svcxprt_rdma *xprt,
 		chunk_off = 0;
 		while (write_len) {
 			ret = send_write(xprt, rqstp,
-					 ntohl(ch->rs_handle),
+					 be32_to_cpu(ch->rs_handle),
 					 rs_offset + chunk_off,
 					 xdr_off,
 					 write_len,
@@ -382,6 +457,7 @@ static int send_reply(struct svcxprt_rdma *rdma,
 		      int byte_count)
 {
 	struct ib_send_wr send_wr;
+	u32 xdr_off;
 	int sge_no;
 	int sge_bytes;
 	int page_no;
@@ -416,8 +492,8 @@ static int send_reply(struct svcxprt_rdma *rdma,
 	ctxt->direction = DMA_TO_DEVICE;
 
 	/* Map the payload indicated by 'byte_count' */
+	xdr_off = 0;
 	for (sge_no = 1; byte_count && sge_no < vec->count; sge_no++) {
-		int xdr_off = 0;
 		sge_bytes = min_t(size_t, vec->sge[sge_no].iov_len, byte_count);
 		byte_count -= sge_bytes;
 		ctxt->sge[sge_no].addr =
@@ -455,6 +531,13 @@ static int send_reply(struct svcxprt_rdma *rdma,
 	}
 	rqstp->rq_next_page = rqstp->rq_respages + 1;
 
+	/* The loop above bumps sc_dma_used for each sge. The
+	 * xdr_buf.tail gets a separate sge, but resides in the
+	 * same page as xdr_buf.head. Don't count it twice.
+	 */
+	if (sge_no > ctxt->count)
+		atomic_dec(&rdma->sc_dma_used);
+
 	if (sge_no > rdma->sc_max_sge) {
 		pr_err("svcrdma: Too many sges (%d)\n", sge_no);
 		goto err;
@@ -515,7 +598,7 @@ int svc_rdma_sendto(struct svc_rqst *rqstp)
 	inline_bytes = rqstp->rq_res.len;
 
 	/* Create the RDMA response header */
-	res_page = svc_rdma_get_page();
+	res_page = alloc_page(GFP_KERNEL | __GFP_NOFAIL);
 	rdma_resp = page_address(res_page);
 	reply_ary = svc_rdma_get_reply_array(rdma_argp);
 	if (reply_ary)
diff --git a/kernel/net/sunrpc/xprtrdma/svc_rdma_transport.c b/kernel/net/sunrpc/xprtrdma/svc_rdma_transport.c
index f609c1c2d..b348b4ade 100644
--- a/kernel/net/sunrpc/xprtrdma/svc_rdma_transport.c
+++ b/kernel/net/sunrpc/xprtrdma/svc_rdma_transport.c
@@ -56,6 +56,7 @@
 
 #define RPCDBG_FACILITY	RPCDBG_SVCXPRT
 
+static struct svcxprt_rdma *rdma_create_xprt(struct svc_serv *, int);
 static struct svc_xprt *svc_rdma_create(struct svc_serv *serv,
 					struct net *net,
 					struct sockaddr *sa, int salen,
@@ -95,16 +96,69 @@ struct svc_xprt_class svc_rdma_class = {
 	.xcl_ident = XPRT_TRANSPORT_RDMA,
 };
 
+#if defined(CONFIG_SUNRPC_BACKCHANNEL)
+static struct svc_xprt *svc_rdma_bc_create(struct svc_serv *, struct net *,
+					   struct sockaddr *, int, int);
+static void svc_rdma_bc_detach(struct svc_xprt *);
+static void svc_rdma_bc_free(struct svc_xprt *);
+
+static struct svc_xprt_ops svc_rdma_bc_ops = {
+	.xpo_create = svc_rdma_bc_create,
+	.xpo_detach = svc_rdma_bc_detach,
+	.xpo_free = svc_rdma_bc_free,
+	.xpo_prep_reply_hdr = svc_rdma_prep_reply_hdr,
+	.xpo_secure_port = svc_rdma_secure_port,
+};
+
+struct svc_xprt_class svc_rdma_bc_class = {
+	.xcl_name = "rdma-bc",
+	.xcl_owner = THIS_MODULE,
+	.xcl_ops = &svc_rdma_bc_ops,
+	.xcl_max_payload = (1024 - RPCRDMA_HDRLEN_MIN)
+};
+
+static struct svc_xprt *svc_rdma_bc_create(struct svc_serv *serv,
+					   struct net *net,
+					   struct sockaddr *sa, int salen,
+					   int flags)
+{
+	struct svcxprt_rdma *cma_xprt;
+	struct svc_xprt *xprt;
+
+	cma_xprt = rdma_create_xprt(serv, 0);
+	if (!cma_xprt)
+		return ERR_PTR(-ENOMEM);
+	xprt = &cma_xprt->sc_xprt;
+
+	svc_xprt_init(net, &svc_rdma_bc_class, xprt, serv);
+	serv->sv_bc_xprt = xprt;
+
+	dprintk("svcrdma: %s(%p)\n", __func__, xprt);
+	return xprt;
+}
+
+static void svc_rdma_bc_detach(struct svc_xprt *xprt)
+{
+	dprintk("svcrdma: %s(%p)\n", __func__, xprt);
+}
+
+static void svc_rdma_bc_free(struct svc_xprt *xprt)
+{
+	struct svcxprt_rdma *rdma =
+		container_of(xprt, struct svcxprt_rdma, sc_xprt);
+
+	dprintk("svcrdma: %s(%p)\n", __func__, xprt);
+	if (xprt)
+		kfree(rdma);
+}
+#endif	/* CONFIG_SUNRPC_BACKCHANNEL */
+
 struct svc_rdma_op_ctxt *svc_rdma_get_context(struct svcxprt_rdma *xprt)
 {
 	struct svc_rdma_op_ctxt *ctxt;
 
-	while (1) {
-		ctxt = kmem_cache_alloc(svc_rdma_ctxt_cachep, GFP_KERNEL);
-		if (ctxt)
-			break;
-		schedule_timeout_uninterruptible(msecs_to_jiffies(500));
-	}
+	ctxt = kmem_cache_alloc(svc_rdma_ctxt_cachep,
+				GFP_KERNEL | __GFP_NOFAIL);
 	ctxt->xprt = xprt;
 	INIT_LIST_HEAD(&ctxt->dto_q);
 	ctxt->count = 0;
@@ -156,12 +210,8 @@ void svc_rdma_put_context(struct svc_rdma_op_ctxt *ctxt, int free_pages)
 struct svc_rdma_req_map *svc_rdma_get_req_map(void)
 {
 	struct svc_rdma_req_map *map;
-	while (1) {
-		map = kmem_cache_alloc(svc_rdma_map_cachep, GFP_KERNEL);
-		if (map)
-			break;
-		schedule_timeout_uninterruptible(msecs_to_jiffies(500));
-	}
+	map = kmem_cache_alloc(svc_rdma_map_cachep,
+			       GFP_KERNEL | __GFP_NOFAIL);
 	map->count = 0;
 	return map;
 }
@@ -175,8 +225,8 @@ void svc_rdma_put_req_map(struct svc_rdma_req_map *map)
 static void cq_event_handler(struct ib_event *event, void *context)
 {
 	struct svc_xprt *xprt = context;
-	dprintk("svcrdma: received CQ event id=%d, context=%p\n",
-		event->event, context);
+	dprintk("svcrdma: received CQ event %s (%d), context=%p\n",
+		ib_event_msg(event->event), event->event, context);
 	set_bit(XPT_CLOSE, &xprt->xpt_flags);
 }
 
@@ -191,8 +241,9 @@ static void qp_event_handler(struct ib_event *event, void *context)
 	case IB_EVENT_COMM_EST:
 	case IB_EVENT_SQ_DRAINED:
 	case IB_EVENT_QP_LAST_WQE_REACHED:
-		dprintk("svcrdma: QP event %d received for QP=%p\n",
-			event->event, event->element.qp);
+		dprintk("svcrdma: QP event %s (%d) received for QP=%p\n",
+			ib_event_msg(event->event), event->event,
+			event->element.qp);
 		break;
 	/* These are considered fatal events */
 	case IB_EVENT_PATH_MIG_ERR:
@@ -201,9 +252,10 @@ static void qp_event_handler(struct ib_event *event, void *context)
 	case IB_EVENT_QP_ACCESS_ERR:
 	case IB_EVENT_DEVICE_FATAL:
 	default:
-		dprintk("svcrdma: QP ERROR event %d received for QP=%p, "
+		dprintk("svcrdma: QP ERROR event %s (%d) received for QP=%p, "
 			"closing transport\n",
-			event->event, event->element.qp);
+			ib_event_msg(event->event), event->event,
+			event->element.qp);
 		set_bit(XPT_CLOSE, &xprt->xpt_flags);
 		break;
 	}
@@ -402,7 +454,8 @@ static void sq_cq_reap(struct svcxprt_rdma *xprt)
 		for (i = 0; i < ret; i++) {
 			wc = &wc_a[i];
 			if (wc->status != IB_WC_SUCCESS) {
-				dprintk("svcrdma: sq wc err status %d\n",
+				dprintk("svcrdma: sq wc err status %s (%d)\n",
+					ib_wc_status_msg(wc->status),
 					wc->status);
 
 				/* Close the transport */
@@ -490,18 +543,6 @@ static struct svcxprt_rdma *rdma_create_xprt(struct svc_serv *serv,
 	return cma_xprt;
 }
 
-struct page *svc_rdma_get_page(void)
-{
-	struct page *page;
-
-	while ((page = alloc_page(GFP_KERNEL)) == NULL) {
-		/* If we can't get memory, wait a bit and try again */
-		printk(KERN_INFO "svcrdma: out of memory...retrying in 1s\n");
-		schedule_timeout_uninterruptible(msecs_to_jiffies(1000));
-	}
-	return page;
-}
-
 int svc_rdma_post_recv(struct svcxprt_rdma *xprt)
 {
 	struct ib_recv_wr recv_wr, *bad_recv_wr;
@@ -520,7 +561,7 @@ int svc_rdma_post_recv(struct svcxprt_rdma *xprt)
 			pr_err("svcrdma: Too many sges (%d)\n", sge_no);
 			goto err_put_ctxt;
 		}
-		page = svc_rdma_get_page();
+		page = alloc_page(GFP_KERNEL | __GFP_NOFAIL);
 		ctxt->pages[sge_no] = page;
 		pa = ib_dma_map_page(xprt->sc_cm_id->device,
 				     page, 0, PAGE_SIZE,
@@ -616,7 +657,8 @@ static int rdma_listen_handler(struct rdma_cm_id *cma_id,
 	switch (event->event) {
 	case RDMA_CM_EVENT_CONNECT_REQUEST:
 		dprintk("svcrdma: Connect request on cma_id=%p, xprt = %p, "
-			"event=%d\n", cma_id, cma_id->context, event->event);
+			"event = %s (%d)\n", cma_id, cma_id->context,
+			rdma_event_msg(event->event), event->event);
 		handle_connect_req(cma_id,
 				   event->param.conn.initiator_depth);
 		break;
@@ -636,7 +678,8 @@ static int rdma_listen_handler(struct rdma_cm_id *cma_id,
 
 	default:
 		dprintk("svcrdma: Unexpected event on listening endpoint %p, "
-			"event=%d\n", cma_id, event->event);
+			"event = %s (%d)\n", cma_id,
+			rdma_event_msg(event->event), event->event);
 		break;
 	}
 
@@ -669,15 +712,18 @@ static int rdma_cma_handler(struct rdma_cm_id *cma_id,
 		break;
 	case RDMA_CM_EVENT_DEVICE_REMOVAL:
 		dprintk("svcrdma: Device removal cma_id=%p, xprt = %p, "
-			"event=%d\n", cma_id, xprt, event->event);
+			"event = %s (%d)\n", cma_id, xprt,
+			rdma_event_msg(event->event), event->event);
 		if (xprt) {
 			set_bit(XPT_CLOSE, &xprt->xpt_flags);
 			svc_xprt_enqueue(xprt);
+			svc_xprt_put(xprt);
 		}
 		break;
 	default:
 		dprintk("svcrdma: Unexpected event on DTO endpoint %p, "
-			"event=%d\n", cma_id, event->event);
+			"event = %s (%d)\n", cma_id,
+			rdma_event_msg(event->event), event->event);
 		break;
 	}
 	return 0;
@@ -704,8 +750,8 @@ static struct svc_xprt *svc_rdma_create(struct svc_serv *serv,
 	if (!cma_xprt)
 		return ERR_PTR(-ENOMEM);
 
-	listen_id = rdma_create_id(rdma_listen_handler, cma_xprt, RDMA_PS_TCP,
-				   IB_QPT_RC);
+	listen_id = rdma_create_id(&init_net, rdma_listen_handler, cma_xprt,
+				   RDMA_PS_TCP, IB_QPT_RC);
 	if (IS_ERR(listen_id)) {
 		ret = PTR_ERR(listen_id);
 		dprintk("svcrdma: rdma_create_id failed = %d\n", ret);
@@ -744,24 +790,27 @@ static struct svc_xprt *svc_rdma_create(struct svc_serv *serv,
 static struct svc_rdma_fastreg_mr *rdma_alloc_frmr(struct svcxprt_rdma *xprt)
 {
 	struct ib_mr *mr;
-	struct ib_fast_reg_page_list *pl;
+	struct scatterlist *sg;
 	struct svc_rdma_fastreg_mr *frmr;
+	u32 num_sg;
 
 	frmr = kmalloc(sizeof(*frmr), GFP_KERNEL);
 	if (!frmr)
 		goto err;
 
-	mr = ib_alloc_fast_reg_mr(xprt->sc_pd, RPCSVC_MAXPAGES);
+	num_sg = min_t(u32, RPCSVC_MAXPAGES, xprt->sc_frmr_pg_list_len);
+	mr = ib_alloc_mr(xprt->sc_pd, IB_MR_TYPE_MEM_REG, num_sg);
 	if (IS_ERR(mr))
 		goto err_free_frmr;
 
-	pl = ib_alloc_fast_reg_page_list(xprt->sc_cm_id->device,
-					 RPCSVC_MAXPAGES);
-	if (IS_ERR(pl))
+	sg = kcalloc(RPCSVC_MAXPAGES, sizeof(*sg), GFP_KERNEL);
+	if (!sg)
 		goto err_free_mr;
 
+	sg_init_table(sg, RPCSVC_MAXPAGES);
+
 	frmr->mr = mr;
-	frmr->page_list = pl;
+	frmr->sg = sg;
 	INIT_LIST_HEAD(&frmr->frmr_list);
 	return frmr;
 
@@ -781,8 +830,8 @@ static void rdma_dealloc_frmr_q(struct svcxprt_rdma *xprt)
 		frmr = list_entry(xprt->sc_frmr_q.next,
 				  struct svc_rdma_fastreg_mr, frmr_list);
 		list_del_init(&frmr->frmr_list);
+		kfree(frmr->sg);
 		ib_dereg_mr(frmr->mr);
-		ib_free_fast_reg_page_list(frmr->page_list);
 		kfree(frmr);
 	}
 }
@@ -796,8 +845,7 @@ struct svc_rdma_fastreg_mr *svc_rdma_get_frmr(struct svcxprt_rdma *rdma)
 		frmr = list_entry(rdma->sc_frmr_q.next,
 				  struct svc_rdma_fastreg_mr, frmr_list);
 		list_del_init(&frmr->frmr_list);
-		frmr->map_len = 0;
-		frmr->page_list_len = 0;
+		frmr->sg_nents = 0;
 	}
 	spin_unlock_bh(&rdma->sc_frmr_q_lock);
 	if (frmr)
@@ -806,25 +854,13 @@ struct svc_rdma_fastreg_mr *svc_rdma_get_frmr(struct svcxprt_rdma *rdma)
 	return rdma_alloc_frmr(rdma);
 }
 
-static void frmr_unmap_dma(struct svcxprt_rdma *xprt,
-			   struct svc_rdma_fastreg_mr *frmr)
-{
-	int page_no;
-	for (page_no = 0; page_no < frmr->page_list_len; page_no++) {
-		dma_addr_t addr = frmr->page_list->page_list[page_no];
-		if (ib_dma_mapping_error(frmr->mr->device, addr))
-			continue;
-		atomic_dec(&xprt->sc_dma_used);
-		ib_dma_unmap_page(frmr->mr->device, addr, PAGE_SIZE,
-				  frmr->direction);
-	}
-}
-
 void svc_rdma_put_frmr(struct svcxprt_rdma *rdma,
 		       struct svc_rdma_fastreg_mr *frmr)
 {
 	if (frmr) {
-		frmr_unmap_dma(rdma, frmr);
+		ib_dma_unmap_sg(rdma->sc_cm_id->device,
+				frmr->sg, frmr->sg_nents, frmr->direction);
+		atomic_dec(&rdma->sc_dma_used);
 		spin_lock_bh(&rdma->sc_frmr_q_lock);
 		WARN_ON_ONCE(!list_empty(&frmr->frmr_list));
 		list_add(&frmr->frmr_list, &rdma->sc_frmr_q);
@@ -848,10 +884,11 @@ static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt)
 	struct svcxprt_rdma *listen_rdma;
 	struct svcxprt_rdma *newxprt = NULL;
 	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;
+	int need_dma_mr = 0;
 	int ret;
 	int i;
 
@@ -884,6 +921,8 @@ static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt)
 	 * capabilities of this particular device */
 	newxprt->sc_max_sge = min((size_t)devattr.max_sge,
 				  (size_t)RPCSVC_MAXPAGES);
+	newxprt->sc_max_sge_rd = min_t(size_t, devattr.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;
@@ -900,22 +939,22 @@ static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt)
 		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,
 					 sq_comp_handler,
 					 cq_event_handler,
 					 newxprt,
-					 newxprt->sc_sq_depth,
-					 0);
+					 &cq_attr);
 	if (IS_ERR(newxprt->sc_sq_cq)) {
 		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,
 					 rq_comp_handler,
 					 cq_event_handler,
 					 newxprt,
-					 newxprt->sc_max_requests,
-					 0);
+					 &cq_attr);
 	if (IS_ERR(newxprt->sc_rq_cq)) {
 		dprintk("svcrdma: error creating RQ CQ for connect request\n");
 		goto errout;
@@ -985,35 +1024,26 @@ 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
 	 */
-	switch (rdma_node_get_transport(newxprt->sc_cm_id->device->node_type)) {
-	case RDMA_TRANSPORT_IWARP:
-		newxprt->sc_dev_caps |= SVCRDMA_DEVCAP_READ_W_INV;
-		if (!(newxprt->sc_dev_caps & SVCRDMA_DEVCAP_FAST_REG)) {
-			need_dma_mr = 1;
-			dma_mr_acc =
-				(IB_ACCESS_LOCAL_WRITE |
-				 IB_ACCESS_REMOTE_WRITE);
-		} else if (!(devattr.device_cap_flags & IB_DEVICE_LOCAL_DMA_LKEY)) {
-			need_dma_mr = 1;
-			dma_mr_acc = IB_ACCESS_LOCAL_WRITE;
-		} else
-			need_dma_mr = 0;
-		break;
-	case RDMA_TRANSPORT_IB:
-		if (!(newxprt->sc_dev_caps & SVCRDMA_DEVCAP_FAST_REG)) {
-			need_dma_mr = 1;
-			dma_mr_acc = IB_ACCESS_LOCAL_WRITE;
-		} else if (!(devattr.device_cap_flags &
-			     IB_DEVICE_LOCAL_DMA_LKEY)) {
-			need_dma_mr = 1;
-			dma_mr_acc = IB_ACCESS_LOCAL_WRITE;
-		} else
-			need_dma_mr = 0;
-		break;
-	default:
+	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))
 		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))
+		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 */
@@ -1067,6 +1097,7 @@ static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt)
 		"    remote_ip       : %pI4\n"
 		"    remote_port     : %d\n"
 		"    max_sge         : %d\n"
+		"    max_sge_rd      : %d\n"
 		"    sq_depth        : %d\n"
 		"    max_requests    : %d\n"
 		"    ord             : %d\n",
@@ -1080,6 +1111,7 @@ static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt)
 		ntohs(((struct sockaddr_in *)&newxprt->sc_cm_id->
 		       route.addr.dst_addr)->sin_port),
 		newxprt->sc_max_sge,
+		newxprt->sc_max_sge_rd,
 		newxprt->sc_sq_depth,
 		newxprt->sc_max_requests,
 		newxprt->sc_ord);
@@ -1222,40 +1254,6 @@ static int svc_rdma_secure_port(struct svc_rqst *rqstp)
 	return 1;
 }
 
-/*
- * Attempt to register the kvec representing the RPC memory with the
- * device.
- *
- * Returns:
- *  NULL : The device does not support fastreg or there were no more
- *         fastreg mr.
- *  frmr : The kvec register request was successfully posted.
- *    <0 : An error was encountered attempting to register the kvec.
- */
-int svc_rdma_fastreg(struct svcxprt_rdma *xprt,
-		     struct svc_rdma_fastreg_mr *frmr)
-{
-	struct ib_send_wr fastreg_wr;
-	u8 key;
-
-	/* Bump the key */
-	key = (u8)(frmr->mr->lkey & 0x000000FF);
-	ib_update_fast_reg_key(frmr->mr, ++key);
-
-	/* Prepare FASTREG WR */
-	memset(&fastreg_wr, 0, sizeof fastreg_wr);
-	fastreg_wr.opcode = IB_WR_FAST_REG_MR;
-	fastreg_wr.send_flags = IB_SEND_SIGNALED;
-	fastreg_wr.wr.fast_reg.iova_start = (unsigned long)frmr->kva;
-	fastreg_wr.wr.fast_reg.page_list = frmr->page_list;
-	fastreg_wr.wr.fast_reg.page_list_len = frmr->page_list_len;
-	fastreg_wr.wr.fast_reg.page_shift = PAGE_SHIFT;
-	fastreg_wr.wr.fast_reg.length = frmr->map_len;
-	fastreg_wr.wr.fast_reg.access_flags = frmr->access_flags;
-	fastreg_wr.wr.fast_reg.rkey = frmr->mr->lkey;
-	return svc_rdma_send(xprt, &fastreg_wr);
-}
-
 int svc_rdma_send(struct svcxprt_rdma *xprt, struct ib_send_wr *wr)
 {
 	struct ib_send_wr *bad_wr, *n_wr;
@@ -1319,11 +1317,11 @@ void svc_rdma_send_error(struct svcxprt_rdma *xprt, struct rpcrdma_msg *rmsgp,
 	struct ib_send_wr err_wr;
 	struct page *p;
 	struct svc_rdma_op_ctxt *ctxt;
-	u32 *va;
+	__be32 *va;
 	int length;
 	int ret;
 
-	p = svc_rdma_get_page();
+	p = alloc_page(GFP_KERNEL | __GFP_NOFAIL);
 	va = page_address(p);
 
 	/* XDR encode error */
diff --git a/kernel/net/sunrpc/xprtrdma/transport.c b/kernel/net/sunrpc/xprtrdma/transport.c
index 54f23b1be..8c545f7d7 100644
--- a/kernel/net/sunrpc/xprtrdma/transport.c
+++ b/kernel/net/sunrpc/xprtrdma/transport.c
@@ -48,7 +48,6 @@
  */
 
 #include <linux/module.h>
-#include <linux/init.h>
 #include <linux/slab.h>
 #include <linux/seq_file.h>
 #include <linux/sunrpc/addr.h>
@@ -59,11 +58,6 @@
 # define RPCDBG_FACILITY	RPCDBG_TRANS
 #endif
 
-MODULE_LICENSE("Dual BSD/GPL");
-
-MODULE_DESCRIPTION("RPC/RDMA Transport for Linux kernel NFS");
-MODULE_AUTHOR("Network Appliance, Inc.");
-
 /*
  * tunables
  */
@@ -181,10 +175,8 @@ xprt_rdma_format_addresses6(struct rpc_xprt *xprt, struct sockaddr *sap)
 }
 
 static void
-xprt_rdma_format_addresses(struct rpc_xprt *xprt)
+xprt_rdma_format_addresses(struct rpc_xprt *xprt, struct sockaddr *sap)
 {
-	struct sockaddr *sap = (struct sockaddr *)
-					&rpcx_to_rdmad(xprt).addr;
 	char buf[128];
 
 	switch (sap->sa_family) {
@@ -246,6 +238,16 @@ xprt_rdma_connect_worker(struct work_struct *work)
 	xprt_clear_connecting(xprt);
 }
 
+static void
+xprt_rdma_inject_disconnect(struct rpc_xprt *xprt)
+{
+	struct rpcrdma_xprt *r_xprt = container_of(xprt, struct rpcrdma_xprt,
+						   rx_xprt);
+
+	pr_info("rpcrdma: injecting transport disconnect on xprt=%p\n", xprt);
+	rdma_disconnect(r_xprt->rx_ia.ri_id);
+}
+
 /*
  * xprt_rdma_destroy
  *
@@ -268,8 +270,8 @@ xprt_rdma_destroy(struct rpc_xprt *xprt)
 
 	xprt_clear_connected(xprt);
 
-	rpcrdma_buffer_destroy(&r_xprt->rx_buf);
 	rpcrdma_ep_destroy(&r_xprt->rx_ep, &r_xprt->rx_ia);
+	rpcrdma_buffer_destroy(&r_xprt->rx_buf);
 	rpcrdma_ia_close(&r_xprt->rx_ia);
 
 	xprt_rdma_free_addresses(xprt);
@@ -298,7 +300,7 @@ xprt_setup_rdma(struct xprt_create *args)
 	struct rpc_xprt *xprt;
 	struct rpcrdma_xprt *new_xprt;
 	struct rpcrdma_ep *new_ep;
-	struct sockaddr_in *sin;
+	struct sockaddr *sap;
 	int rc;
 
 	if (args->addrlen > sizeof(xprt->addr)) {
@@ -329,26 +331,20 @@ xprt_setup_rdma(struct xprt_create *args)
 	 * Set up RDMA-specific connect data.
 	 */
 
-	/* Put server RDMA address in local cdata */
-	memcpy(&cdata.addr, args->dstaddr, args->addrlen);
+	sap = (struct sockaddr *)&cdata.addr;
+	memcpy(sap, args->dstaddr, args->addrlen);
 
 	/* Ensure xprt->addr holds valid server TCP (not RDMA)
 	 * address, for any side protocols which peek at it */
 	xprt->prot = IPPROTO_TCP;
 	xprt->addrlen = args->addrlen;
-	memcpy(&xprt->addr, &cdata.addr, xprt->addrlen);
+	memcpy(&xprt->addr, sap, xprt->addrlen);
 
-	sin = (struct sockaddr_in *)&cdata.addr;
-	if (ntohs(sin->sin_port) != 0)
+	if (rpc_get_port(sap))
 		xprt_set_bound(xprt);
 
-	dprintk("RPC:       %s: %pI4:%u\n",
-		__func__, &sin->sin_addr.s_addr, ntohs(sin->sin_port));
-
-	/* Set max requests */
 	cdata.max_requests = xprt->max_reqs;
 
-	/* Set some length limits */
 	cdata.rsize = RPCRDMA_MAX_SEGS * PAGE_SIZE; /* RDMA write max */
 	cdata.wsize = RPCRDMA_MAX_SEGS * PAGE_SIZE; /* RDMA read max */
 
@@ -371,8 +367,7 @@ xprt_setup_rdma(struct xprt_create *args)
 
 	new_xprt = rpcx_to_rdmax(xprt);
 
-	rc = rpcrdma_ia_open(new_xprt, (struct sockaddr *) &cdata.addr,
-				xprt_rdma_memreg_strategy);
+	rc = rpcrdma_ia_open(new_xprt, sap, xprt_rdma_memreg_strategy);
 	if (rc)
 		goto out1;
 
@@ -405,7 +400,7 @@ xprt_setup_rdma(struct xprt_create *args)
 	INIT_DELAYED_WORK(&new_xprt->rx_connect_worker,
 			  xprt_rdma_connect_worker);
 
-	xprt_rdma_format_addresses(xprt);
+	xprt_rdma_format_addresses(xprt, sap);
 	xprt->max_payload = new_xprt->rx_ia.ri_ops->ro_maxpages(new_xprt);
 	if (xprt->max_payload == 0)
 		goto out4;
@@ -416,6 +411,9 @@ xprt_setup_rdma(struct xprt_create *args)
 	if (!try_module_get(THIS_MODULE))
 		goto out4;
 
+	dprintk("RPC:       %s: %s:%s\n", __func__,
+		xprt->address_strings[RPC_DISPLAY_ADDR],
+		xprt->address_strings[RPC_DISPLAY_PORT]);
 	return xprt;
 
 out4:
@@ -618,12 +616,6 @@ xprt_rdma_send_request(struct rpc_task *task)
 	if (req->rl_reply == NULL) 		/* e.g. reconnection */
 		rpcrdma_recv_buffer_get(req);
 
-	if (req->rl_reply) {
-		req->rl_reply->rr_func = rpcrdma_reply_handler;
-		/* this need only be done once, but... */
-		req->rl_reply->rr_xprt = xprt;
-	}
-
 	/* Must suppress retransmit to maintain credits */
 	if (req->rl_connect_cookie == xprt->connect_cookie)
 		goto drop_connection;
@@ -655,31 +647,41 @@ static void xprt_rdma_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
 	if (xprt_connected(xprt))
 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
 
-	seq_printf(seq,
-	  "\txprt:\trdma %u %lu %lu %lu %ld %lu %lu %lu %Lu %Lu "
-	  "%lu %lu %lu %Lu %Lu %Lu %Lu %lu %lu %lu\n",
-
-	   0,	/* need a local port? */
-	   xprt->stat.bind_count,
-	   xprt->stat.connect_count,
-	   xprt->stat.connect_time,
-	   idle_time,
-	   xprt->stat.sends,
-	   xprt->stat.recvs,
-	   xprt->stat.bad_xids,
-	   xprt->stat.req_u,
-	   xprt->stat.bklog_u,
-
-	   r_xprt->rx_stats.read_chunk_count,
-	   r_xprt->rx_stats.write_chunk_count,
-	   r_xprt->rx_stats.reply_chunk_count,
-	   r_xprt->rx_stats.total_rdma_request,
-	   r_xprt->rx_stats.total_rdma_reply,
-	   r_xprt->rx_stats.pullup_copy_count,
-	   r_xprt->rx_stats.fixup_copy_count,
-	   r_xprt->rx_stats.hardway_register_count,
-	   r_xprt->rx_stats.failed_marshal_count,
-	   r_xprt->rx_stats.bad_reply_count);
+	seq_puts(seq, "\txprt:\trdma ");
+	seq_printf(seq, "%u %lu %lu %lu %ld %lu %lu %lu %llu %llu ",
+		   0,	/* need a local port? */
+		   xprt->stat.bind_count,
+		   xprt->stat.connect_count,
+		   xprt->stat.connect_time,
+		   idle_time,
+		   xprt->stat.sends,
+		   xprt->stat.recvs,
+		   xprt->stat.bad_xids,
+		   xprt->stat.req_u,
+		   xprt->stat.bklog_u);
+	seq_printf(seq, "%lu %lu %lu %llu %llu %llu %llu %lu %lu %lu %lu\n",
+		   r_xprt->rx_stats.read_chunk_count,
+		   r_xprt->rx_stats.write_chunk_count,
+		   r_xprt->rx_stats.reply_chunk_count,
+		   r_xprt->rx_stats.total_rdma_request,
+		   r_xprt->rx_stats.total_rdma_reply,
+		   r_xprt->rx_stats.pullup_copy_count,
+		   r_xprt->rx_stats.fixup_copy_count,
+		   r_xprt->rx_stats.hardway_register_count,
+		   r_xprt->rx_stats.failed_marshal_count,
+		   r_xprt->rx_stats.bad_reply_count,
+		   r_xprt->rx_stats.nomsg_call_count);
+}
+
+static int
+xprt_rdma_enable_swap(struct rpc_xprt *xprt)
+{
+	return 0;
+}
+
+static void
+xprt_rdma_disable_swap(struct rpc_xprt *xprt)
+{
 }
 
 /*
@@ -700,7 +702,16 @@ static struct rpc_xprt_ops xprt_rdma_procs = {
 	.send_request		= xprt_rdma_send_request,
 	.close			= xprt_rdma_close,
 	.destroy		= xprt_rdma_destroy,
-	.print_stats		= xprt_rdma_print_stats
+	.print_stats		= xprt_rdma_print_stats,
+	.enable_swap		= xprt_rdma_enable_swap,
+	.disable_swap		= xprt_rdma_disable_swap,
+	.inject_disconnect	= xprt_rdma_inject_disconnect,
+#if defined(CONFIG_SUNRPC_BACKCHANNEL)
+	.bc_setup		= xprt_rdma_bc_setup,
+	.bc_up			= xprt_rdma_bc_up,
+	.bc_free_rqst		= xprt_rdma_bc_free_rqst,
+	.bc_destroy		= xprt_rdma_bc_destroy,
+#endif
 };
 
 static struct xprt_class xprt_rdma = {
@@ -711,7 +722,7 @@ static struct xprt_class xprt_rdma = {
 	.setup			= xprt_setup_rdma,
 };
 
-static void __exit xprt_rdma_cleanup(void)
+void xprt_rdma_cleanup(void)
 {
 	int rc;
 
@@ -726,17 +737,32 @@ static void __exit xprt_rdma_cleanup(void)
 	if (rc)
 		dprintk("RPC:       %s: xprt_unregister returned %i\n",
 			__func__, rc);
+
+	rpcrdma_destroy_wq();
+	frwr_destroy_recovery_wq();
 }
 
-static int __init xprt_rdma_init(void)
+int xprt_rdma_init(void)
 {
 	int rc;
 
-	rc = xprt_register_transport(&xprt_rdma);
-
+	rc = frwr_alloc_recovery_wq();
 	if (rc)
 		return rc;
 
+	rc = rpcrdma_alloc_wq();
+	if (rc) {
+		frwr_destroy_recovery_wq();
+		return rc;
+	}
+
+	rc = xprt_register_transport(&xprt_rdma);
+	if (rc) {
+		rpcrdma_destroy_wq();
+		frwr_destroy_recovery_wq();
+		return rc;
+	}
+
 	dprintk("RPCRDMA Module Init, register RPC RDMA transport\n");
 
 	dprintk("Defaults:\n");
@@ -753,6 +779,3 @@ static int __init xprt_rdma_init(void)
 #endif
 	return 0;
 }
-
-module_init(xprt_rdma_init);
-module_exit(xprt_rdma_cleanup);
diff --git a/kernel/net/sunrpc/xprtrdma/verbs.c b/kernel/net/sunrpc/xprtrdma/verbs.c
index 4870d272e..eadd16551 100644
--- a/kernel/net/sunrpc/xprtrdma/verbs.c
+++ b/kernel/net/sunrpc/xprtrdma/verbs.c
@@ -52,6 +52,7 @@
 #include <linux/prefetch.h>
 #include <linux/sunrpc/addr.h>
 #include <asm/bitops.h>
+#include <linux/module.h> /* try_module_get()/module_put() */
 
 #include "xprt_rdma.h"
 
@@ -67,79 +68,33 @@
  * internal functions
  */
 
-/*
- * handle replies in tasklet context, using a single, global list
- * rdma tasklet function -- just turn around and call the func
- * for all replies on the list
- */
-
-static DEFINE_SPINLOCK(rpcrdma_tk_lock_g);
-static LIST_HEAD(rpcrdma_tasklets_g);
+static struct workqueue_struct *rpcrdma_receive_wq;
 
-static void
-rpcrdma_run_tasklet(unsigned long data)
+int
+rpcrdma_alloc_wq(void)
 {
-	struct rpcrdma_rep *rep;
-	void (*func)(struct rpcrdma_rep *);
-	unsigned long flags;
+	struct workqueue_struct *recv_wq;
 
-	data = data;
-	spin_lock_irqsave(&rpcrdma_tk_lock_g, flags);
-	while (!list_empty(&rpcrdma_tasklets_g)) {
-		rep = list_entry(rpcrdma_tasklets_g.next,
-				 struct rpcrdma_rep, rr_list);
-		list_del(&rep->rr_list);
-		func = rep->rr_func;
-		rep->rr_func = NULL;
-		spin_unlock_irqrestore(&rpcrdma_tk_lock_g, flags);
-
-		if (func)
-			func(rep);
-		else
-			rpcrdma_recv_buffer_put(rep);
-
-		spin_lock_irqsave(&rpcrdma_tk_lock_g, flags);
-	}
-	spin_unlock_irqrestore(&rpcrdma_tk_lock_g, flags);
-}
+	recv_wq = alloc_workqueue("xprtrdma_receive",
+				  WQ_MEM_RECLAIM | WQ_UNBOUND | WQ_HIGHPRI,
+				  0);
+	if (!recv_wq)
+		return -ENOMEM;
 
-static DECLARE_TASKLET(rpcrdma_tasklet_g, rpcrdma_run_tasklet, 0UL);
-
-static const char * const async_event[] = {
-	"CQ error",
-	"QP fatal error",
-	"QP request error",
-	"QP access error",
-	"communication established",
-	"send queue drained",
-	"path migration successful",
-	"path mig error",
-	"device fatal error",
-	"port active",
-	"port error",
-	"LID change",
-	"P_key change",
-	"SM change",
-	"SRQ error",
-	"SRQ limit reached",
-	"last WQE reached",
-	"client reregister",
-	"GID change",
-};
-
-#define ASYNC_MSG(status)					\
-	((status) < ARRAY_SIZE(async_event) ?			\
-		async_event[(status)] : "unknown async error")
+	rpcrdma_receive_wq = recv_wq;
+	return 0;
+}
 
-static void
-rpcrdma_schedule_tasklet(struct list_head *sched_list)
+void
+rpcrdma_destroy_wq(void)
 {
-	unsigned long flags;
+	struct workqueue_struct *wq;
 
-	spin_lock_irqsave(&rpcrdma_tk_lock_g, flags);
-	list_splice_tail(sched_list, &rpcrdma_tasklets_g);
-	spin_unlock_irqrestore(&rpcrdma_tk_lock_g, flags);
-	tasklet_schedule(&rpcrdma_tasklet_g);
+	if (rpcrdma_receive_wq) {
+		wq = rpcrdma_receive_wq;
+		rpcrdma_receive_wq = NULL;
+		destroy_workqueue(wq);
+	}
 }
 
 static void
@@ -148,7 +103,7 @@ rpcrdma_qp_async_error_upcall(struct ib_event *event, void *context)
 	struct rpcrdma_ep *ep = context;
 
 	pr_err("RPC:       %s: %s on device %s ep %p\n",
-	       __func__, ASYNC_MSG(event->event),
+	       __func__, ib_event_msg(event->event),
 		event->device->name, context);
 	if (ep->rep_connected == 1) {
 		ep->rep_connected = -EIO;
@@ -163,7 +118,7 @@ rpcrdma_cq_async_error_upcall(struct ib_event *event, void *context)
 	struct rpcrdma_ep *ep = context;
 
 	pr_err("RPC:       %s: %s on device %s ep %p\n",
-	       __func__, ASYNC_MSG(event->event),
+	       __func__, ib_event_msg(event->event),
 		event->device->name, context);
 	if (ep->rep_connected == 1) {
 		ep->rep_connected = -EIO;
@@ -172,35 +127,6 @@ rpcrdma_cq_async_error_upcall(struct ib_event *event, void *context)
 	}
 }
 
-static const char * const wc_status[] = {
-	"success",
-	"local length error",
-	"local QP operation error",
-	"local EE context operation error",
-	"local protection error",
-	"WR flushed",
-	"memory management operation error",
-	"bad response error",
-	"local access error",
-	"remote invalid request error",
-	"remote access error",
-	"remote operation error",
-	"transport retry counter exceeded",
-	"RNR retry counter exceeded",
-	"local RDD violation error",
-	"remove invalid RD request",
-	"operation aborted",
-	"invalid EE context number",
-	"invalid EE context state",
-	"fatal error",
-	"response timeout error",
-	"general error",
-};
-
-#define COMPLETION_MSG(status)					\
-	((status) < ARRAY_SIZE(wc_status) ?			\
-		wc_status[(status)] : "unexpected completion error")
-
 static void
 rpcrdma_sendcq_process_wc(struct ib_wc *wc)
 {
@@ -209,7 +135,7 @@ rpcrdma_sendcq_process_wc(struct ib_wc *wc)
 		if (wc->status != IB_WC_SUCCESS &&
 		    wc->status != IB_WC_WR_FLUSH_ERR)
 			pr_err("RPC:       %s: SEND: %s\n",
-			       __func__, COMPLETION_MSG(wc->status));
+			       __func__, ib_wc_status_msg(wc->status));
 	} else {
 		struct rpcrdma_mw *r;
 
@@ -218,63 +144,54 @@ rpcrdma_sendcq_process_wc(struct ib_wc *wc)
 	}
 }
 
-static int
-rpcrdma_sendcq_poll(struct ib_cq *cq, struct rpcrdma_ep *ep)
+/* The common case is a single send completion is waiting. By
+ * passing two WC entries to ib_poll_cq, a return code of 1
+ * means there is exactly one WC waiting and no more. We don't
+ * have to invoke ib_poll_cq again to know that the CQ has been
+ * properly drained.
+ */
+static void
+rpcrdma_sendcq_poll(struct ib_cq *cq)
 {
-	struct ib_wc *wcs;
-	int budget, count, rc;
+	struct ib_wc *pos, wcs[2];
+	int count, rc;
 
-	budget = RPCRDMA_WC_BUDGET / RPCRDMA_POLLSIZE;
 	do {
-		wcs = ep->rep_send_wcs;
+		pos = wcs;
 
-		rc = ib_poll_cq(cq, RPCRDMA_POLLSIZE, wcs);
-		if (rc <= 0)
-			return rc;
+		rc = ib_poll_cq(cq, ARRAY_SIZE(wcs), pos);
+		if (rc < 0)
+			break;
 
 		count = rc;
 		while (count-- > 0)
-			rpcrdma_sendcq_process_wc(wcs++);
-	} while (rc == RPCRDMA_POLLSIZE && --budget);
-	return 0;
+			rpcrdma_sendcq_process_wc(pos++);
+	} while (rc == ARRAY_SIZE(wcs));
+	return;
 }
 
-/*
- * Handle send, fast_reg_mr, and local_inv completions.
- *
- * Send events are typically suppressed and thus do not result
- * in an upcall. Occasionally one is signaled, however. This
- * prevents the provider's completion queue from wrapping and
- * losing a completion.
+/* Handle provider send completion upcalls.
  */
 static void
 rpcrdma_sendcq_upcall(struct ib_cq *cq, void *cq_context)
 {
-	struct rpcrdma_ep *ep = (struct rpcrdma_ep *)cq_context;
-	int rc;
-
-	rc = rpcrdma_sendcq_poll(cq, ep);
-	if (rc) {
-		dprintk("RPC:       %s: ib_poll_cq failed: %i\n",
-			__func__, rc);
-		return;
-	}
+	do {
+		rpcrdma_sendcq_poll(cq);
+	} while (ib_req_notify_cq(cq, IB_CQ_NEXT_COMP |
+				  IB_CQ_REPORT_MISSED_EVENTS) > 0);
+}
 
-	rc = ib_req_notify_cq(cq,
-			IB_CQ_NEXT_COMP | IB_CQ_REPORT_MISSED_EVENTS);
-	if (rc == 0)
-		return;
-	if (rc < 0) {
-		dprintk("RPC:       %s: ib_req_notify_cq failed: %i\n",
-			__func__, rc);
-		return;
-	}
+static void
+rpcrdma_receive_worker(struct work_struct *work)
+{
+	struct rpcrdma_rep *rep =
+			container_of(work, struct rpcrdma_rep, rr_work);
 
-	rpcrdma_sendcq_poll(cq, ep);
+	rpcrdma_reply_handler(rep);
 }
 
 static void
-rpcrdma_recvcq_process_wc(struct ib_wc *wc, struct list_head *sched_list)
+rpcrdma_recvcq_process_wc(struct ib_wc *wc)
 {
 	struct rpcrdma_rep *rep =
 			(struct rpcrdma_rep *)(unsigned long)wc->wr_id;
@@ -291,126 +208,70 @@ rpcrdma_recvcq_process_wc(struct ib_wc *wc, struct list_head *sched_list)
 		__func__, rep, wc->byte_len);
 
 	rep->rr_len = wc->byte_len;
-	ib_dma_sync_single_for_cpu(rdmab_to_ia(rep->rr_buffer)->ri_id->device,
+	ib_dma_sync_single_for_cpu(rep->rr_device,
 				   rdmab_addr(rep->rr_rdmabuf),
 				   rep->rr_len, DMA_FROM_DEVICE);
 	prefetch(rdmab_to_msg(rep->rr_rdmabuf));
 
 out_schedule:
-	list_add_tail(&rep->rr_list, sched_list);
+	queue_work(rpcrdma_receive_wq, &rep->rr_work);
 	return;
+
 out_fail:
 	if (wc->status != IB_WC_WR_FLUSH_ERR)
 		pr_err("RPC:       %s: rep %p: %s\n",
-		       __func__, rep, COMPLETION_MSG(wc->status));
-	rep->rr_len = ~0U;
+		       __func__, rep, ib_wc_status_msg(wc->status));
+	rep->rr_len = RPCRDMA_BAD_LEN;
 	goto out_schedule;
 }
 
-static int
-rpcrdma_recvcq_poll(struct ib_cq *cq, struct rpcrdma_ep *ep)
+/* The wc array is on stack: automatic memory is always CPU-local.
+ *
+ * struct ib_wc is 64 bytes, making the poll array potentially
+ * large. But this is at the bottom of the call chain. Further
+ * substantial work is done in another thread.
+ */
+static void
+rpcrdma_recvcq_poll(struct ib_cq *cq)
 {
-	struct list_head sched_list;
-	struct ib_wc *wcs;
-	int budget, count, rc;
+	struct ib_wc *pos, wcs[4];
+	int count, rc;
 
-	INIT_LIST_HEAD(&sched_list);
-	budget = RPCRDMA_WC_BUDGET / RPCRDMA_POLLSIZE;
 	do {
-		wcs = ep->rep_recv_wcs;
+		pos = wcs;
 
-		rc = ib_poll_cq(cq, RPCRDMA_POLLSIZE, wcs);
-		if (rc <= 0)
-			goto out_schedule;
+		rc = ib_poll_cq(cq, ARRAY_SIZE(wcs), pos);
+		if (rc < 0)
+			break;
 
 		count = rc;
 		while (count-- > 0)
-			rpcrdma_recvcq_process_wc(wcs++, &sched_list);
-	} while (rc == RPCRDMA_POLLSIZE && --budget);
-	rc = 0;
-
-out_schedule:
-	rpcrdma_schedule_tasklet(&sched_list);
-	return rc;
+			rpcrdma_recvcq_process_wc(pos++);
+	} while (rc == ARRAY_SIZE(wcs));
 }
 
-/*
- * Handle receive completions.
- *
- * It is reentrant but processes single events in order to maintain
- * ordering of receives to keep server credits.
- *
- * It is the responsibility of the scheduled tasklet to return
- * recv buffers to the pool. NOTE: this affects synchronization of
- * connection shutdown. That is, the structures required for
- * the completion of the reply handler must remain intact until
- * all memory has been reclaimed.
+/* Handle provider receive completion upcalls.
  */
 static void
 rpcrdma_recvcq_upcall(struct ib_cq *cq, void *cq_context)
 {
-	struct rpcrdma_ep *ep = (struct rpcrdma_ep *)cq_context;
-	int rc;
-
-	rc = rpcrdma_recvcq_poll(cq, ep);
-	if (rc) {
-		dprintk("RPC:       %s: ib_poll_cq failed: %i\n",
-			__func__, rc);
-		return;
-	}
-
-	rc = ib_req_notify_cq(cq,
-			IB_CQ_NEXT_COMP | IB_CQ_REPORT_MISSED_EVENTS);
-	if (rc == 0)
-		return;
-	if (rc < 0) {
-		dprintk("RPC:       %s: ib_req_notify_cq failed: %i\n",
-			__func__, rc);
-		return;
-	}
-
-	rpcrdma_recvcq_poll(cq, ep);
+	do {
+		rpcrdma_recvcq_poll(cq);
+	} while (ib_req_notify_cq(cq, IB_CQ_NEXT_COMP |
+				  IB_CQ_REPORT_MISSED_EVENTS) > 0);
 }
 
 static void
 rpcrdma_flush_cqs(struct rpcrdma_ep *ep)
 {
 	struct ib_wc wc;
-	LIST_HEAD(sched_list);
 
 	while (ib_poll_cq(ep->rep_attr.recv_cq, 1, &wc) > 0)
-		rpcrdma_recvcq_process_wc(&wc, &sched_list);
-	if (!list_empty(&sched_list))
-		rpcrdma_schedule_tasklet(&sched_list);
+		rpcrdma_recvcq_process_wc(&wc);
 	while (ib_poll_cq(ep->rep_attr.send_cq, 1, &wc) > 0)
 		rpcrdma_sendcq_process_wc(&wc);
 }
 
-#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
-static const char * const conn[] = {
-	"address resolved",
-	"address error",
-	"route resolved",
-	"route error",
-	"connect request",
-	"connect response",
-	"connect error",
-	"unreachable",
-	"rejected",
-	"established",
-	"disconnected",
-	"device removal",
-	"multicast join",
-	"multicast error",
-	"address change",
-	"timewait exit",
-};
-
-#define CONNECTION_MSG(status)						\
-	((status) < ARRAY_SIZE(conn) ?					\
-		conn[(status)] : "unrecognized connection error")
-#endif
-
 static int
 rpcrdma_conn_upcall(struct rdma_cm_id *id, struct rdma_cm_event *event)
 {
@@ -476,7 +337,7 @@ connected:
 	default:
 		dprintk("RPC:       %s: %pIS:%u (ep 0x%p): %s\n",
 			__func__, sap, rpc_get_port(sap), ep,
-			CONNECTION_MSG(event->event));
+			rdma_event_msg(event->event));
 		break;
 	}
 
@@ -487,7 +348,7 @@ connected:
 
 		pr_info("rpcrdma: connection to %pIS:%u on %s, memreg '%s', %d credits, %d responders%s\n",
 			sap, rpc_get_port(sap),
-			ia->ri_id->device->name,
+			ia->ri_device->name,
 			ia->ri_ops->ro_displayname,
 			xprt->rx_buf.rb_max_requests,
 			ird, ird < 4 && ird < tird / 2 ? " (low!)" : "");
@@ -500,6 +361,14 @@ connected:
 	return 0;
 }
 
+static void rpcrdma_destroy_id(struct rdma_cm_id *id)
+{
+	if (id) {
+		module_put(id->device->owner);
+		rdma_destroy_id(id);
+	}
+}
+
 static struct rdma_cm_id *
 rpcrdma_create_id(struct rpcrdma_xprt *xprt,
 			struct rpcrdma_ia *ia, struct sockaddr *addr)
@@ -509,7 +378,8 @@ rpcrdma_create_id(struct rpcrdma_xprt *xprt,
 
 	init_completion(&ia->ri_done);
 
-	id = rdma_create_id(rpcrdma_conn_upcall, xprt, RDMA_PS_TCP, IB_QPT_RC);
+	id = rdma_create_id(&init_net, rpcrdma_conn_upcall, xprt, RDMA_PS_TCP,
+			    IB_QPT_RC);
 	if (IS_ERR(id)) {
 		rc = PTR_ERR(id);
 		dprintk("RPC:       %s: rdma_create_id() failed %i\n",
@@ -526,6 +396,17 @@ rpcrdma_create_id(struct rpcrdma_xprt *xprt,
 	}
 	wait_for_completion_interruptible_timeout(&ia->ri_done,
 				msecs_to_jiffies(RDMA_RESOLVE_TIMEOUT) + 1);
+
+	/* FIXME:
+	 * Until xprtrdma supports DEVICE_REMOVAL, the provider must
+	 * be pinned while there are active NFS/RDMA mounts to prevent
+	 * hangs and crashes at umount time.
+	 */
+	if (!ia->ri_async_rc && !try_module_get(id->device->owner)) {
+		dprintk("RPC:       %s: Failed to get device module\n",
+			__func__);
+		ia->ri_async_rc = -ENODEV;
+	}
 	rc = ia->ri_async_rc;
 	if (rc)
 		goto out;
@@ -535,16 +416,17 @@ rpcrdma_create_id(struct rpcrdma_xprt *xprt,
 	if (rc) {
 		dprintk("RPC:       %s: rdma_resolve_route() failed %i\n",
 			__func__, rc);
-		goto out;
+		goto put;
 	}
 	wait_for_completion_interruptible_timeout(&ia->ri_done,
 				msecs_to_jiffies(RDMA_RESOLVE_TIMEOUT) + 1);
 	rc = ia->ri_async_rc;
 	if (rc)
-		goto out;
+		goto put;
 
 	return id;
-
+put:
+	module_put(id->device->owner);
 out:
 	rdma_destroy_id(id);
 	return ERR_PTR(rc);
@@ -579,17 +461,20 @@ rpcrdma_clean_cq(struct ib_cq *cq)
 int
 rpcrdma_ia_open(struct rpcrdma_xprt *xprt, struct sockaddr *addr, int memreg)
 {
-	int rc, mem_priv;
 	struct rpcrdma_ia *ia = &xprt->rx_ia;
 	struct ib_device_attr *devattr = &ia->ri_devattr;
+	int rc;
+
+	ia->ri_dma_mr = NULL;
 
 	ia->ri_id = rpcrdma_create_id(xprt, ia, addr);
 	if (IS_ERR(ia->ri_id)) {
 		rc = PTR_ERR(ia->ri_id);
 		goto out1;
 	}
+	ia->ri_device = ia->ri_id->device;
 
-	ia->ri_pd = ib_alloc_pd(ia->ri_id->device);
+	ia->ri_pd = ib_alloc_pd(ia->ri_device);
 	if (IS_ERR(ia->ri_pd)) {
 		rc = PTR_ERR(ia->ri_pd);
 		dprintk("RPC:       %s: ib_alloc_pd() failed %i\n",
@@ -597,69 +482,39 @@ rpcrdma_ia_open(struct rpcrdma_xprt *xprt, struct sockaddr *addr, int memreg)
 		goto out2;
 	}
 
-	rc = ib_query_device(ia->ri_id->device, devattr);
+	rc = ib_query_device(ia->ri_device, devattr);
 	if (rc) {
 		dprintk("RPC:       %s: ib_query_device failed %d\n",
 			__func__, rc);
 		goto out3;
 	}
 
-	if (devattr->device_cap_flags & IB_DEVICE_LOCAL_DMA_LKEY) {
-		ia->ri_have_dma_lkey = 1;
-		ia->ri_dma_lkey = ia->ri_id->device->local_dma_lkey;
-	}
-
 	if (memreg == RPCRDMA_FRMR) {
-		/* Requires both frmr reg and local dma lkey */
-		if (((devattr->device_cap_flags &
-		     (IB_DEVICE_MEM_MGT_EXTENSIONS|IB_DEVICE_LOCAL_DMA_LKEY)) !=
-		    (IB_DEVICE_MEM_MGT_EXTENSIONS|IB_DEVICE_LOCAL_DMA_LKEY)) ||
-		      (devattr->max_fast_reg_page_list_len == 0)) {
+		if (!(devattr->device_cap_flags & IB_DEVICE_MEM_MGT_EXTENSIONS) ||
+		    (devattr->max_fast_reg_page_list_len == 0)) {
 			dprintk("RPC:       %s: FRMR registration "
 				"not supported by HCA\n", __func__);
 			memreg = RPCRDMA_MTHCAFMR;
 		}
 	}
 	if (memreg == RPCRDMA_MTHCAFMR) {
-		if (!ia->ri_id->device->alloc_fmr) {
+		if (!ia->ri_device->alloc_fmr) {
 			dprintk("RPC:       %s: MTHCAFMR registration "
 				"not supported by HCA\n", __func__);
-			memreg = RPCRDMA_ALLPHYSICAL;
+			rc = -EINVAL;
+			goto out3;
 		}
 	}
 
-	/*
-	 * Optionally obtain an underlying physical identity mapping in
-	 * order to do a memory window-based bind. This base registration
-	 * is protected from remote access - that is enabled only by binding
-	 * for the specific bytes targeted during each RPC operation, and
-	 * revoked after the corresponding completion similar to a storage
-	 * adapter.
-	 */
 	switch (memreg) {
 	case RPCRDMA_FRMR:
 		ia->ri_ops = &rpcrdma_frwr_memreg_ops;
 		break;
 	case RPCRDMA_ALLPHYSICAL:
 		ia->ri_ops = &rpcrdma_physical_memreg_ops;
-		mem_priv = IB_ACCESS_LOCAL_WRITE |
-				IB_ACCESS_REMOTE_WRITE |
-				IB_ACCESS_REMOTE_READ;
-		goto register_setup;
+		break;
 	case RPCRDMA_MTHCAFMR:
 		ia->ri_ops = &rpcrdma_fmr_memreg_ops;
-		if (ia->ri_have_dma_lkey)
-			break;
-		mem_priv = IB_ACCESS_LOCAL_WRITE;
-	register_setup:
-		ia->ri_bind_mem = ib_get_dma_mr(ia->ri_pd, mem_priv);
-		if (IS_ERR(ia->ri_bind_mem)) {
-			printk(KERN_ALERT "%s: ib_get_dma_mr for "
-				"phys register failed with %lX\n",
-				__func__, PTR_ERR(ia->ri_bind_mem));
-			rc = -ENOMEM;
-			goto out3;
-		}
 		break;
 	default:
 		printk(KERN_ERR "RPC: Unsupported memory "
@@ -670,9 +525,6 @@ 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);
 
-	/* Else will do memory reg/dereg for each chunk */
-	ia->ri_memreg_strategy = memreg;
-
 	rwlock_init(&ia->ri_qplock);
 	return 0;
 
@@ -680,7 +532,7 @@ out3:
 	ib_dealloc_pd(ia->ri_pd);
 	ia->ri_pd = NULL;
 out2:
-	rdma_destroy_id(ia->ri_id);
+	rpcrdma_destroy_id(ia->ri_id);
 	ia->ri_id = NULL;
 out1:
 	return rc;
@@ -694,25 +546,17 @@ out1:
 void
 rpcrdma_ia_close(struct rpcrdma_ia *ia)
 {
-	int rc;
-
 	dprintk("RPC:       %s: entering\n", __func__);
-	if (ia->ri_bind_mem != NULL) {
-		rc = ib_dereg_mr(ia->ri_bind_mem);
-		dprintk("RPC:       %s: ib_dereg_mr returned %i\n",
-			__func__, rc);
-	}
 	if (ia->ri_id != NULL && !IS_ERR(ia->ri_id)) {
 		if (ia->ri_id->qp)
 			rdma_destroy_qp(ia->ri_id);
-		rdma_destroy_id(ia->ri_id);
+		rpcrdma_destroy_id(ia->ri_id);
 		ia->ri_id = NULL;
 	}
-	if (ia->ri_pd != NULL && !IS_ERR(ia->ri_pd)) {
-		rc = ib_dealloc_pd(ia->ri_pd);
-		dprintk("RPC:       %s: ib_dealloc_pd returned %i\n",
-			__func__, rc);
-	}
+
+	/* If the pd is still busy, xprtrdma missed freeing a resource */
+	if (ia->ri_pd && !IS_ERR(ia->ri_pd))
+		ib_dealloc_pd(ia->ri_pd);
 }
 
 /*
@@ -724,35 +568,44 @@ rpcrdma_ep_create(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia,
 {
 	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) {
+		dprintk("RPC:       %s: insufficient sge's available\n",
+			__func__);
+		return -ENOMEM;
+	}
+
+	if (devattr->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;
+
 	/* check provider's send/recv wr limits */
-	if (cdata->max_requests > devattr->max_qp_wr)
-		cdata->max_requests = devattr->max_qp_wr;
+	if (cdata->max_requests > max_qp_wr)
+		cdata->max_requests = max_qp_wr;
 
 	ep->rep_attr.event_handler = rpcrdma_qp_async_error_upcall;
 	ep->rep_attr.qp_context = ep;
 	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;
 	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_send_sge = (cdata->padding ? 4 : 2);
+	ep->rep_attr.cap.max_recv_wr += RPCRDMA_BACKWARD_WRS;
+	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;
 	ep->rep_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
 	ep->rep_attr.qp_type = IB_QPT_RC;
 	ep->rep_attr.port_num = ~0;
 
-	if (cdata->padding) {
-		ep->rep_padbuf = rpcrdma_alloc_regbuf(ia, cdata->padding,
-						      GFP_KERNEL);
-		if (IS_ERR(ep->rep_padbuf))
-			return PTR_ERR(ep->rep_padbuf);
-	} else
-		ep->rep_padbuf = NULL;
-
 	dprintk("RPC:       %s: requested max: dtos: send %d recv %d; "
 		"iovs: send %d recv %d\n",
 		__func__,
@@ -771,9 +624,9 @@ rpcrdma_ep_create(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia,
 	init_waitqueue_head(&ep->rep_connect_wait);
 	INIT_DELAYED_WORK(&ep->rep_connect_worker, rpcrdma_connect_worker);
 
-	sendcq = ib_create_cq(ia->ri_id->device, rpcrdma_sendcq_upcall,
-				  rpcrdma_cq_async_error_upcall, ep,
-				  ep->rep_attr.cap.max_send_wr + 1, 0);
+	cq_attr.cqe = ep->rep_attr.cap.max_send_wr + 1;
+	sendcq = ib_create_cq(ia->ri_device, rpcrdma_sendcq_upcall,
+			      rpcrdma_cq_async_error_upcall, NULL, &cq_attr);
 	if (IS_ERR(sendcq)) {
 		rc = PTR_ERR(sendcq);
 		dprintk("RPC:       %s: failed to create send CQ: %i\n",
@@ -788,9 +641,9 @@ rpcrdma_ep_create(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia,
 		goto out2;
 	}
 
-	recvcq = ib_create_cq(ia->ri_id->device, rpcrdma_recvcq_upcall,
-				  rpcrdma_cq_async_error_upcall, ep,
-				  ep->rep_attr.cap.max_recv_wr + 1, 0);
+	cq_attr.cqe = ep->rep_attr.cap.max_recv_wr + 1;
+	recvcq = ib_create_cq(ia->ri_device, rpcrdma_recvcq_upcall,
+			      rpcrdma_cq_async_error_upcall, NULL, &cq_attr);
 	if (IS_ERR(recvcq)) {
 		rc = PTR_ERR(recvcq);
 		dprintk("RPC:       %s: failed to create recv CQ: %i\n",
@@ -835,7 +688,8 @@ out2:
 		dprintk("RPC:       %s: ib_destroy_cq returned %i\n",
 			__func__, err);
 out1:
-	rpcrdma_free_regbuf(ia, ep->rep_padbuf);
+	if (ia->ri_dma_mr)
+		ib_dereg_mr(ia->ri_dma_mr);
 	return rc;
 }
 
@@ -856,25 +710,32 @@ rpcrdma_ep_destroy(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
 
 	cancel_delayed_work_sync(&ep->rep_connect_worker);
 
-	if (ia->ri_id->qp) {
+	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) {
 		rdma_destroy_qp(ia->ri_id);
 		ia->ri_id->qp = NULL;
 	}
 
-	rpcrdma_free_regbuf(ia, ep->rep_padbuf);
-
-	rpcrdma_clean_cq(ep->rep_attr.recv_cq);
 	rc = ib_destroy_cq(ep->rep_attr.recv_cq);
 	if (rc)
 		dprintk("RPC:       %s: ib_destroy_cq returned %i\n",
 			__func__, rc);
 
-	rpcrdma_clean_cq(ep->rep_attr.send_cq);
 	rc = ib_destroy_cq(ep->rep_attr.send_cq);
 	if (rc)
 		dprintk("RPC:       %s: ib_destroy_cq returned %i\n",
 			__func__, rc);
+
+	if (ia->ri_dma_mr) {
+		rc = ib_dereg_mr(ia->ri_dma_mr);
+		dprintk("RPC:       %s: ib_dereg_mr returned %i\n",
+			__func__, rc);
+	}
 }
 
 /*
@@ -896,8 +757,6 @@ retry:
 		rpcrdma_flush_cqs(ep);
 
 		xprt = container_of(ia, struct rpcrdma_xprt, rx_ia);
-		ia->ri_ops->ro_reset(xprt);
-
 		id = rpcrdma_create_id(xprt, ia,
 				(struct sockaddr *)&xprt->rx_data.addr);
 		if (IS_ERR(id)) {
@@ -911,10 +770,10 @@ retry:
 		 * More stuff I haven't thought of!
 		 * Rrrgh!
 		 */
-		if (ia->ri_id->device != id->device) {
+		if (ia->ri_device != id->device) {
 			printk("RPC:       %s: can't reconnect on "
 				"different device!\n", __func__);
-			rdma_destroy_id(id);
+			rpcrdma_destroy_id(id);
 			rc = -ENETUNREACH;
 			goto out;
 		}
@@ -923,7 +782,7 @@ retry:
 		if (rc) {
 			dprintk("RPC:       %s: rdma_create_qp failed %i\n",
 				__func__, rc);
-			rdma_destroy_id(id);
+			rpcrdma_destroy_id(id);
 			rc = -ENETUNREACH;
 			goto out;
 		}
@@ -934,7 +793,7 @@ retry:
 		write_unlock(&ia->ri_qplock);
 
 		rdma_destroy_qp(old);
-		rdma_destroy_id(old);
+		rpcrdma_destroy_id(old);
 	} else {
 		dprintk("RPC:       %s: connecting...\n", __func__);
 		rc = rdma_create_qp(ia->ri_id, ia->ri_pd, &ep->rep_attr);
@@ -983,7 +842,21 @@ retry:
 		}
 		rc = ep->rep_connected;
 	} else {
+		struct rpcrdma_xprt *r_xprt;
+		unsigned int extras;
+
 		dprintk("RPC:       %s: connected\n", __func__);
+
+		r_xprt = container_of(ia, struct rpcrdma_xprt, rx_ia);
+		extras = r_xprt->rx_buf.rb_bc_srv_max_requests;
+
+		if (extras) {
+			rc = rpcrdma_ep_post_extra_recv(r_xprt, extras);
+			if (rc)
+				pr_warn("%s: rpcrdma_ep_post_extra_recv: %i\n",
+					__func__, rc);
+				rc = 0;
+		}
 	}
 
 out:
@@ -1020,20 +893,25 @@ rpcrdma_ep_disconnect(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
 	}
 }
 
-static struct rpcrdma_req *
+struct rpcrdma_req *
 rpcrdma_create_req(struct rpcrdma_xprt *r_xprt)
 {
+	struct rpcrdma_buffer *buffer = &r_xprt->rx_buf;
 	struct rpcrdma_req *req;
 
 	req = kzalloc(sizeof(*req), GFP_KERNEL);
 	if (req == NULL)
 		return ERR_PTR(-ENOMEM);
 
+	INIT_LIST_HEAD(&req->rl_free);
+	spin_lock(&buffer->rb_reqslock);
+	list_add(&req->rl_all, &buffer->rb_allreqs);
+	spin_unlock(&buffer->rb_reqslock);
 	req->rl_buffer = &r_xprt->rx_buf;
 	return req;
 }
 
-static struct rpcrdma_rep *
+struct rpcrdma_rep *
 rpcrdma_create_rep(struct rpcrdma_xprt *r_xprt)
 {
 	struct rpcrdma_create_data_internal *cdata = &r_xprt->rx_data;
@@ -1053,7 +931,9 @@ rpcrdma_create_rep(struct rpcrdma_xprt *r_xprt)
 		goto out_free;
 	}
 
-	rep->rr_buffer = &r_xprt->rx_buf;
+	rep->rr_device = ia->ri_device;
+	rep->rr_rxprt = r_xprt;
+	INIT_WORK(&rep->rr_work, rpcrdma_receive_worker);
 	return rep;
 
 out_free:
@@ -1067,44 +947,21 @@ rpcrdma_buffer_create(struct rpcrdma_xprt *r_xprt)
 {
 	struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
 	struct rpcrdma_ia *ia = &r_xprt->rx_ia;
-	struct rpcrdma_create_data_internal *cdata = &r_xprt->rx_data;
-	char *p;
-	size_t len;
 	int i, rc;
 
-	buf->rb_max_requests = cdata->max_requests;
+	buf->rb_max_requests = r_xprt->rx_data.max_requests;
+	buf->rb_bc_srv_max_requests = 0;
 	spin_lock_init(&buf->rb_lock);
 
-	/* Need to allocate:
-	 *   1.  arrays for send and recv pointers
-	 *   2.  arrays of struct rpcrdma_req to fill in pointers
-	 *   3.  array of struct rpcrdma_rep for replies
-	 * Send/recv buffers in req/rep need to be registered
-	 */
-	len = buf->rb_max_requests *
-		(sizeof(struct rpcrdma_req *) + sizeof(struct rpcrdma_rep *));
-
-	p = kzalloc(len, GFP_KERNEL);
-	if (p == NULL) {
-		dprintk("RPC:       %s: req_t/rep_t/pad kzalloc(%zd) failed\n",
-			__func__, len);
-		rc = -ENOMEM;
-		goto out;
-	}
-	buf->rb_pool = p;	/* for freeing it later */
-
-	buf->rb_send_bufs = (struct rpcrdma_req **) p;
-	p = (char *) &buf->rb_send_bufs[buf->rb_max_requests];
-	buf->rb_recv_bufs = (struct rpcrdma_rep **) p;
-	p = (char *) &buf->rb_recv_bufs[buf->rb_max_requests];
-
 	rc = ia->ri_ops->ro_init(r_xprt);
 	if (rc)
 		goto out;
 
+	INIT_LIST_HEAD(&buf->rb_send_bufs);
+	INIT_LIST_HEAD(&buf->rb_allreqs);
+	spin_lock_init(&buf->rb_reqslock);
 	for (i = 0; i < buf->rb_max_requests; i++) {
 		struct rpcrdma_req *req;
-		struct rpcrdma_rep *rep;
 
 		req = rpcrdma_create_req(r_xprt);
 		if (IS_ERR(req)) {
@@ -1113,7 +970,13 @@ rpcrdma_buffer_create(struct rpcrdma_xprt *r_xprt)
 			rc = PTR_ERR(req);
 			goto out;
 		}
-		buf->rb_send_bufs[i] = req;
+		req->rl_backchannel = false;
+		list_add(&req->rl_free, &buf->rb_send_bufs);
+	}
+
+	INIT_LIST_HEAD(&buf->rb_recv_bufs);
+	for (i = 0; i < buf->rb_max_requests + 2; i++) {
+		struct rpcrdma_rep *rep;
 
 		rep = rpcrdma_create_rep(r_xprt);
 		if (IS_ERR(rep)) {
@@ -1122,7 +985,7 @@ rpcrdma_buffer_create(struct rpcrdma_xprt *r_xprt)
 			rc = PTR_ERR(rep);
 			goto out;
 		}
-		buf->rb_recv_bufs[i] = rep;
+		list_add(&rep->rr_list, &buf->rb_recv_bufs);
 	}
 
 	return 0;
@@ -1131,22 +994,38 @@ out:
 	return rc;
 }
 
+static struct rpcrdma_req *
+rpcrdma_buffer_get_req_locked(struct rpcrdma_buffer *buf)
+{
+	struct rpcrdma_req *req;
+
+	req = list_first_entry(&buf->rb_send_bufs,
+			       struct rpcrdma_req, rl_free);
+	list_del(&req->rl_free);
+	return req;
+}
+
+static struct rpcrdma_rep *
+rpcrdma_buffer_get_rep_locked(struct rpcrdma_buffer *buf)
+{
+	struct rpcrdma_rep *rep;
+
+	rep = list_first_entry(&buf->rb_recv_bufs,
+			       struct rpcrdma_rep, rr_list);
+	list_del(&rep->rr_list);
+	return rep;
+}
+
 static void
 rpcrdma_destroy_rep(struct rpcrdma_ia *ia, struct rpcrdma_rep *rep)
 {
-	if (!rep)
-		return;
-
 	rpcrdma_free_regbuf(ia, rep->rr_rdmabuf);
 	kfree(rep);
 }
 
-static void
+void
 rpcrdma_destroy_req(struct rpcrdma_ia *ia, struct rpcrdma_req *req)
 {
-	if (!req)
-		return;
-
 	rpcrdma_free_regbuf(ia, req->rl_sendbuf);
 	rpcrdma_free_regbuf(ia, req->rl_rdmabuf);
 	kfree(req);
@@ -1156,220 +1035,88 @@ void
 rpcrdma_buffer_destroy(struct rpcrdma_buffer *buf)
 {
 	struct rpcrdma_ia *ia = rdmab_to_ia(buf);
-	int i;
-
-	/* clean up in reverse order from create
-	 *   1.  recv mr memory (mr free, then kfree)
-	 *   2.  send mr memory (mr free, then kfree)
-	 *   3.  MWs
-	 */
-	dprintk("RPC:       %s: entering\n", __func__);
-
-	for (i = 0; i < buf->rb_max_requests; i++) {
-		if (buf->rb_recv_bufs)
-			rpcrdma_destroy_rep(ia, buf->rb_recv_bufs[i]);
-		if (buf->rb_send_bufs)
-			rpcrdma_destroy_req(ia, buf->rb_send_bufs[i]);
-	}
-
-	ia->ri_ops->ro_destroy(buf);
 
-	kfree(buf->rb_pool);
-}
+	while (!list_empty(&buf->rb_recv_bufs)) {
+		struct rpcrdma_rep *rep;
 
-/* "*mw" can be NULL when rpcrdma_buffer_get_mrs() fails, leaving
- * some req segments uninitialized.
- */
-static void
-rpcrdma_buffer_put_mr(struct rpcrdma_mw **mw, struct rpcrdma_buffer *buf)
-{
-	if (*mw) {
-		list_add_tail(&(*mw)->mw_list, &buf->rb_mws);
-		*mw = NULL;
+		rep = rpcrdma_buffer_get_rep_locked(buf);
+		rpcrdma_destroy_rep(ia, rep);
 	}
-}
 
-/* Cycle mw's back in reverse order, and "spin" them.
- * This delays and scrambles reuse as much as possible.
- */
-static void
-rpcrdma_buffer_put_mrs(struct rpcrdma_req *req, struct rpcrdma_buffer *buf)
-{
-	struct rpcrdma_mr_seg *seg = req->rl_segments;
-	struct rpcrdma_mr_seg *seg1 = seg;
-	int i;
+	spin_lock(&buf->rb_reqslock);
+	while (!list_empty(&buf->rb_allreqs)) {
+		struct rpcrdma_req *req;
 
-	for (i = 1, seg++; i < RPCRDMA_MAX_SEGS; seg++, i++)
-		rpcrdma_buffer_put_mr(&seg->rl_mw, buf);
-	rpcrdma_buffer_put_mr(&seg1->rl_mw, buf);
-}
+		req = list_first_entry(&buf->rb_allreqs,
+				       struct rpcrdma_req, rl_all);
+		list_del(&req->rl_all);
 
-static void
-rpcrdma_buffer_put_sendbuf(struct rpcrdma_req *req, struct rpcrdma_buffer *buf)
-{
-	buf->rb_send_bufs[--buf->rb_send_index] = req;
-	req->rl_niovs = 0;
-	if (req->rl_reply) {
-		buf->rb_recv_bufs[--buf->rb_recv_index] = req->rl_reply;
-		req->rl_reply->rr_func = NULL;
-		req->rl_reply = NULL;
+		spin_unlock(&buf->rb_reqslock);
+		rpcrdma_destroy_req(ia, req);
+		spin_lock(&buf->rb_reqslock);
 	}
-}
-
-/* rpcrdma_unmap_one() was already done during deregistration.
- * Redo only the ib_post_send().
- */
-static void
-rpcrdma_retry_local_inv(struct rpcrdma_mw *r, struct rpcrdma_ia *ia)
-{
-	struct rpcrdma_xprt *r_xprt =
-				container_of(ia, struct rpcrdma_xprt, rx_ia);
-	struct ib_send_wr invalidate_wr, *bad_wr;
-	int rc;
-
-	dprintk("RPC:       %s: FRMR %p is stale\n", __func__, r);
-
-	/* When this FRMR is re-inserted into rb_mws, it is no longer stale */
-	r->r.frmr.fr_state = FRMR_IS_INVALID;
-
-	memset(&invalidate_wr, 0, sizeof(invalidate_wr));
-	invalidate_wr.wr_id = (unsigned long)(void *)r;
-	invalidate_wr.opcode = IB_WR_LOCAL_INV;
-	invalidate_wr.ex.invalidate_rkey = r->r.frmr.fr_mr->rkey;
-	DECR_CQCOUNT(&r_xprt->rx_ep);
-
-	dprintk("RPC:       %s: frmr %p invalidating rkey %08x\n",
-		__func__, r, r->r.frmr.fr_mr->rkey);
+	spin_unlock(&buf->rb_reqslock);
 
-	read_lock(&ia->ri_qplock);
-	rc = ib_post_send(ia->ri_id->qp, &invalidate_wr, &bad_wr);
-	read_unlock(&ia->ri_qplock);
-	if (rc) {
-		/* Force rpcrdma_buffer_get() to retry */
-		r->r.frmr.fr_state = FRMR_IS_STALE;
-		dprintk("RPC:       %s: ib_post_send failed, %i\n",
-			__func__, rc);
-	}
+	ia->ri_ops->ro_destroy(buf);
 }
 
-static void
-rpcrdma_retry_flushed_linv(struct list_head *stale,
-			   struct rpcrdma_buffer *buf)
+struct rpcrdma_mw *
+rpcrdma_get_mw(struct rpcrdma_xprt *r_xprt)
 {
-	struct rpcrdma_ia *ia = rdmab_to_ia(buf);
-	struct list_head *pos;
-	struct rpcrdma_mw *r;
-	unsigned long flags;
-
-	list_for_each(pos, stale) {
-		r = list_entry(pos, struct rpcrdma_mw, mw_list);
-		rpcrdma_retry_local_inv(r, ia);
-	}
-
-	spin_lock_irqsave(&buf->rb_lock, flags);
-	list_splice_tail(stale, &buf->rb_mws);
-	spin_unlock_irqrestore(&buf->rb_lock, flags);
-}
+	struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
+	struct rpcrdma_mw *mw = NULL;
 
-static struct rpcrdma_req *
-rpcrdma_buffer_get_frmrs(struct rpcrdma_req *req, struct rpcrdma_buffer *buf,
-			 struct list_head *stale)
-{
-	struct rpcrdma_mw *r;
-	int i;
-
-	i = RPCRDMA_MAX_SEGS - 1;
-	while (!list_empty(&buf->rb_mws)) {
-		r = list_entry(buf->rb_mws.next,
-			       struct rpcrdma_mw, mw_list);
-		list_del(&r->mw_list);
-		if (r->r.frmr.fr_state == FRMR_IS_STALE) {
-			list_add(&r->mw_list, stale);
-			continue;
-		}
-		req->rl_segments[i].rl_mw = r;
-		if (unlikely(i-- == 0))
-			return req;	/* Success */
+	spin_lock(&buf->rb_mwlock);
+	if (!list_empty(&buf->rb_mws)) {
+		mw = list_first_entry(&buf->rb_mws,
+				      struct rpcrdma_mw, mw_list);
+		list_del_init(&mw->mw_list);
 	}
+	spin_unlock(&buf->rb_mwlock);
 
-	/* Not enough entries on rb_mws for this req */
-	rpcrdma_buffer_put_sendbuf(req, buf);
-	rpcrdma_buffer_put_mrs(req, buf);
-	return NULL;
+	if (!mw)
+		pr_err("RPC:       %s: no MWs available\n", __func__);
+	return mw;
 }
 
-static struct rpcrdma_req *
-rpcrdma_buffer_get_fmrs(struct rpcrdma_req *req, struct rpcrdma_buffer *buf)
+void
+rpcrdma_put_mw(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mw *mw)
 {
-	struct rpcrdma_mw *r;
-	int i;
-
-	i = RPCRDMA_MAX_SEGS - 1;
-	while (!list_empty(&buf->rb_mws)) {
-		r = list_entry(buf->rb_mws.next,
-			       struct rpcrdma_mw, mw_list);
-		list_del(&r->mw_list);
-		req->rl_segments[i].rl_mw = r;
-		if (unlikely(i-- == 0))
-			return req;	/* Success */
-	}
+	struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
 
-	/* Not enough entries on rb_mws for this req */
-	rpcrdma_buffer_put_sendbuf(req, buf);
-	rpcrdma_buffer_put_mrs(req, buf);
-	return NULL;
+	spin_lock(&buf->rb_mwlock);
+	list_add_tail(&mw->mw_list, &buf->rb_mws);
+	spin_unlock(&buf->rb_mwlock);
 }
 
 /*
  * Get a set of request/reply buffers.
  *
- * Reply buffer (if needed) is attached to send buffer upon return.
- * Rule:
- *    rb_send_index and rb_recv_index MUST always be pointing to the
- *    *next* available buffer (non-NULL). They are incremented after
- *    removing buffers, and decremented *before* returning them.
+ * Reply buffer (if available) is attached to send buffer upon return.
  */
 struct rpcrdma_req *
 rpcrdma_buffer_get(struct rpcrdma_buffer *buffers)
 {
-	struct rpcrdma_ia *ia = rdmab_to_ia(buffers);
-	struct list_head stale;
 	struct rpcrdma_req *req;
-	unsigned long flags;
-
-	spin_lock_irqsave(&buffers->rb_lock, flags);
-	if (buffers->rb_send_index == buffers->rb_max_requests) {
-		spin_unlock_irqrestore(&buffers->rb_lock, flags);
-		dprintk("RPC:       %s: out of request buffers\n", __func__);
-		return ((struct rpcrdma_req *)NULL);
-	}
 
-	req = buffers->rb_send_bufs[buffers->rb_send_index];
-	if (buffers->rb_send_index < buffers->rb_recv_index) {
-		dprintk("RPC:       %s: %d extra receives outstanding (ok)\n",
-			__func__,
-			buffers->rb_recv_index - buffers->rb_send_index);
-		req->rl_reply = NULL;
-	} else {
-		req->rl_reply = buffers->rb_recv_bufs[buffers->rb_recv_index];
-		buffers->rb_recv_bufs[buffers->rb_recv_index++] = NULL;
-	}
-	buffers->rb_send_bufs[buffers->rb_send_index++] = NULL;
+	spin_lock(&buffers->rb_lock);
+	if (list_empty(&buffers->rb_send_bufs))
+		goto out_reqbuf;
+	req = rpcrdma_buffer_get_req_locked(buffers);
+	if (list_empty(&buffers->rb_recv_bufs))
+		goto out_repbuf;
+	req->rl_reply = rpcrdma_buffer_get_rep_locked(buffers);
+	spin_unlock(&buffers->rb_lock);
+	return req;
 
-	INIT_LIST_HEAD(&stale);
-	switch (ia->ri_memreg_strategy) {
-	case RPCRDMA_FRMR:
-		req = rpcrdma_buffer_get_frmrs(req, buffers, &stale);
-		break;
-	case RPCRDMA_MTHCAFMR:
-		req = rpcrdma_buffer_get_fmrs(req, buffers);
-		break;
-	default:
-		break;
-	}
-	spin_unlock_irqrestore(&buffers->rb_lock, flags);
-	if (!list_empty(&stale))
-		rpcrdma_retry_flushed_linv(&stale, buffers);
+out_reqbuf:
+	spin_unlock(&buffers->rb_lock);
+	pr_warn("RPC:       %s: out of request buffers\n", __func__);
+	return NULL;
+out_repbuf:
+	spin_unlock(&buffers->rb_lock);
+	pr_warn("RPC:       %s: out of reply buffers\n", __func__);
+	req->rl_reply = NULL;
 	return req;
 }
 
@@ -1381,39 +1128,31 @@ void
 rpcrdma_buffer_put(struct rpcrdma_req *req)
 {
 	struct rpcrdma_buffer *buffers = req->rl_buffer;
-	struct rpcrdma_ia *ia = rdmab_to_ia(buffers);
-	unsigned long flags;
+	struct rpcrdma_rep *rep = req->rl_reply;
 
-	spin_lock_irqsave(&buffers->rb_lock, flags);
-	rpcrdma_buffer_put_sendbuf(req, buffers);
-	switch (ia->ri_memreg_strategy) {
-	case RPCRDMA_FRMR:
-	case RPCRDMA_MTHCAFMR:
-		rpcrdma_buffer_put_mrs(req, buffers);
-		break;
-	default:
-		break;
-	}
-	spin_unlock_irqrestore(&buffers->rb_lock, flags);
+	req->rl_niovs = 0;
+	req->rl_reply = NULL;
+
+	spin_lock(&buffers->rb_lock);
+	list_add_tail(&req->rl_free, &buffers->rb_send_bufs);
+	if (rep)
+		list_add_tail(&rep->rr_list, &buffers->rb_recv_bufs);
+	spin_unlock(&buffers->rb_lock);
 }
 
 /*
  * Recover reply buffers from pool.
- * This happens when recovering from error conditions.
- * Post-increment counter/array index.
+ * This happens when recovering from disconnect.
  */
 void
 rpcrdma_recv_buffer_get(struct rpcrdma_req *req)
 {
 	struct rpcrdma_buffer *buffers = req->rl_buffer;
-	unsigned long flags;
 
-	spin_lock_irqsave(&buffers->rb_lock, flags);
-	if (buffers->rb_recv_index < buffers->rb_max_requests) {
-		req->rl_reply = buffers->rb_recv_bufs[buffers->rb_recv_index];
-		buffers->rb_recv_bufs[buffers->rb_recv_index++] = NULL;
-	}
-	spin_unlock_irqrestore(&buffers->rb_lock, flags);
+	spin_lock(&buffers->rb_lock);
+	if (!list_empty(&buffers->rb_recv_bufs))
+		req->rl_reply = rpcrdma_buffer_get_rep_locked(buffers);
+	spin_unlock(&buffers->rb_lock);
 }
 
 /*
@@ -1423,13 +1162,11 @@ rpcrdma_recv_buffer_get(struct rpcrdma_req *req)
 void
 rpcrdma_recv_buffer_put(struct rpcrdma_rep *rep)
 {
-	struct rpcrdma_buffer *buffers = rep->rr_buffer;
-	unsigned long flags;
+	struct rpcrdma_buffer *buffers = &rep->rr_rxprt->rx_buf;
 
-	rep->rr_func = NULL;
-	spin_lock_irqsave(&buffers->rb_lock, flags);
-	buffers->rb_recv_bufs[--buffers->rb_recv_index] = rep;
-	spin_unlock_irqrestore(&buffers->rb_lock, flags);
+	spin_lock(&buffers->rb_lock);
+	list_add_tail(&rep->rr_list, &buffers->rb_recv_bufs);
+	spin_unlock(&buffers->rb_lock);
 }
 
 /*
@@ -1444,75 +1181,6 @@ rpcrdma_mapping_error(struct rpcrdma_mr_seg *seg)
 		(unsigned long long)seg->mr_dma, seg->mr_dmalen);
 }
 
-static int
-rpcrdma_register_internal(struct rpcrdma_ia *ia, void *va, int len,
-				struct ib_mr **mrp, struct ib_sge *iov)
-{
-	struct ib_phys_buf ipb;
-	struct ib_mr *mr;
-	int rc;
-
-	/*
-	 * All memory passed here was kmalloc'ed, therefore phys-contiguous.
-	 */
-	iov->addr = ib_dma_map_single(ia->ri_id->device,
-			va, len, DMA_BIDIRECTIONAL);
-	if (ib_dma_mapping_error(ia->ri_id->device, iov->addr))
-		return -ENOMEM;
-
-	iov->length = len;
-
-	if (ia->ri_have_dma_lkey) {
-		*mrp = NULL;
-		iov->lkey = ia->ri_dma_lkey;
-		return 0;
-	} else if (ia->ri_bind_mem != NULL) {
-		*mrp = NULL;
-		iov->lkey = ia->ri_bind_mem->lkey;
-		return 0;
-	}
-
-	ipb.addr = iov->addr;
-	ipb.size = iov->length;
-	mr = ib_reg_phys_mr(ia->ri_pd, &ipb, 1,
-			IB_ACCESS_LOCAL_WRITE, &iov->addr);
-
-	dprintk("RPC:       %s: phys convert: 0x%llx "
-			"registered 0x%llx length %d\n",
-			__func__, (unsigned long long)ipb.addr,
-			(unsigned long long)iov->addr, len);
-
-	if (IS_ERR(mr)) {
-		*mrp = NULL;
-		rc = PTR_ERR(mr);
-		dprintk("RPC:       %s: failed with %i\n", __func__, rc);
-	} else {
-		*mrp = mr;
-		iov->lkey = mr->lkey;
-		rc = 0;
-	}
-
-	return rc;
-}
-
-static int
-rpcrdma_deregister_internal(struct rpcrdma_ia *ia,
-				struct ib_mr *mr, struct ib_sge *iov)
-{
-	int rc;
-
-	ib_dma_unmap_single(ia->ri_id->device,
-			iov->addr, iov->length, DMA_BIDIRECTIONAL);
-
-	if (NULL == mr)
-		return 0;
-
-	rc = ib_dereg_mr(mr);
-	if (rc)
-		dprintk("RPC:       %s: ib_dereg_mr failed %i\n", __func__, rc);
-	return rc;
-}
-
 /**
  * rpcrdma_alloc_regbuf - kmalloc and register memory for SEND/RECV buffers
  * @ia: controlling rpcrdma_ia
@@ -1532,26 +1200,29 @@ struct rpcrdma_regbuf *
 rpcrdma_alloc_regbuf(struct rpcrdma_ia *ia, size_t size, gfp_t flags)
 {
 	struct rpcrdma_regbuf *rb;
-	int rc;
+	struct ib_sge *iov;
 
-	rc = -ENOMEM;
 	rb = kmalloc(sizeof(*rb) + size, flags);
 	if (rb == NULL)
 		goto out;
 
-	rb->rg_size = size;
-	rb->rg_owner = NULL;
-	rc = rpcrdma_register_internal(ia, rb->rg_base, size,
-				       &rb->rg_mr, &rb->rg_iov);
-	if (rc)
+	iov = &rb->rg_iov;
+	iov->addr = ib_dma_map_single(ia->ri_device,
+				      (void *)rb->rg_base, size,
+				      DMA_BIDIRECTIONAL);
+	if (ib_dma_mapping_error(ia->ri_device, iov->addr))
 		goto out_free;
 
+	iov->length = size;
+	iov->lkey = ia->ri_pd->local_dma_lkey;
+	rb->rg_size = size;
+	rb->rg_owner = NULL;
 	return rb;
 
 out_free:
 	kfree(rb);
 out:
-	return ERR_PTR(rc);
+	return ERR_PTR(-ENOMEM);
 }
 
 /**
@@ -1562,10 +1233,15 @@ out:
 void
 rpcrdma_free_regbuf(struct rpcrdma_ia *ia, struct rpcrdma_regbuf *rb)
 {
-	if (rb) {
-		rpcrdma_deregister_internal(ia, rb->rg_mr, &rb->rg_iov);
-		kfree(rb);
-	}
+	struct ib_sge *iov;
+
+	if (!rb)
+		return;
+
+	iov = &rb->rg_iov;
+	ib_dma_unmap_single(ia->ri_device,
+			    iov->addr, iov->length, DMA_BIDIRECTIONAL);
+	kfree(rb);
 }
 
 /*
@@ -1578,9 +1254,11 @@ rpcrdma_ep_post(struct rpcrdma_ia *ia,
 		struct rpcrdma_ep *ep,
 		struct rpcrdma_req *req)
 {
+	struct ib_device *device = ia->ri_device;
 	struct ib_send_wr send_wr, *send_wr_fail;
 	struct rpcrdma_rep *rep = req->rl_reply;
-	int rc;
+	struct ib_sge *iov = req->rl_send_iov;
+	int i, rc;
 
 	if (rep) {
 		rc = rpcrdma_ep_post_recv(ia, ep, rep);
@@ -1591,19 +1269,15 @@ rpcrdma_ep_post(struct rpcrdma_ia *ia,
 
 	send_wr.next = NULL;
 	send_wr.wr_id = RPCRDMA_IGNORE_COMPLETION;
-	send_wr.sg_list = req->rl_send_iov;
+	send_wr.sg_list = iov;
 	send_wr.num_sge = req->rl_niovs;
 	send_wr.opcode = IB_WR_SEND;
-	if (send_wr.num_sge == 4)	/* no need to sync any pad (constant) */
-		ib_dma_sync_single_for_device(ia->ri_id->device,
-			req->rl_send_iov[3].addr, req->rl_send_iov[3].length,
-			DMA_TO_DEVICE);
-	ib_dma_sync_single_for_device(ia->ri_id->device,
-		req->rl_send_iov[1].addr, req->rl_send_iov[1].length,
-		DMA_TO_DEVICE);
-	ib_dma_sync_single_for_device(ia->ri_id->device,
-		req->rl_send_iov[0].addr, req->rl_send_iov[0].length,
-		DMA_TO_DEVICE);
+
+	for (i = 0; i < send_wr.num_sge; i++)
+		ib_dma_sync_single_for_device(device, iov[i].addr,
+					      iov[i].length, DMA_TO_DEVICE);
+	dprintk("RPC:       %s: posting %d s/g entries\n",
+		__func__, send_wr.num_sge);
 
 	if (DECR_CQCOUNT(ep) > 0)
 		send_wr.send_flags = 0;
@@ -1636,7 +1310,7 @@ rpcrdma_ep_post_recv(struct rpcrdma_ia *ia,
 	recv_wr.sg_list = &rep->rr_rdmabuf->rg_iov;
 	recv_wr.num_sge = 1;
 
-	ib_dma_sync_single_for_cpu(ia->ri_id->device,
+	ib_dma_sync_single_for_cpu(ia->ri_device,
 				   rdmab_addr(rep->rr_rdmabuf),
 				   rdmab_length(rep->rr_rdmabuf),
 				   DMA_BIDIRECTIONAL);
@@ -1649,6 +1323,47 @@ rpcrdma_ep_post_recv(struct rpcrdma_ia *ia,
 	return rc;
 }
 
+/**
+ * rpcrdma_ep_post_extra_recv - Post buffers for incoming backchannel requests
+ * @r_xprt: transport associated with these backchannel resources
+ * @min_reqs: minimum number of incoming requests expected
+ *
+ * Returns zero if all requested buffers were posted, or a negative errno.
+ */
+int
+rpcrdma_ep_post_extra_recv(struct rpcrdma_xprt *r_xprt, unsigned int count)
+{
+	struct rpcrdma_buffer *buffers = &r_xprt->rx_buf;
+	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);
+		if (list_empty(&buffers->rb_recv_bufs))
+			goto out_reqbuf;
+		rep = rpcrdma_buffer_get_rep_locked(buffers);
+		spin_unlock_irqrestore(&buffers->rb_lock, flags);
+
+		rc = rpcrdma_ep_post_recv(ia, ep, rep);
+		if (rc)
+			goto out_rc;
+	}
+
+	return 0;
+
+out_reqbuf:
+	spin_unlock_irqrestore(&buffers->rb_lock, flags);
+	pr_warn("%s: no extra receive buffers\n", __func__);
+	return -ENOMEM;
+
+out_rc:
+	rpcrdma_recv_buffer_put(rep);
+	return rc;
+}
+
 /* How many chunk list items fit within our inline buffers?
  */
 unsigned int
diff --git a/kernel/net/sunrpc/xprtrdma/xprt_rdma.h b/kernel/net/sunrpc/xprtrdma/xprt_rdma.h
index 78e0b8bea..ac7f8d4f6 100644
--- a/kernel/net/sunrpc/xprtrdma/xprt_rdma.h
+++ b/kernel/net/sunrpc/xprtrdma/xprt_rdma.h
@@ -51,7 +51,6 @@
 #include <linux/sunrpc/clnt.h> 		/* rpc_xprt */
 #include <linux/sunrpc/rpc_rdma.h> 	/* RPC/RDMA protocol */
 #include <linux/sunrpc/xprtrdma.h> 	/* xprt parameters */
-#include <linux/sunrpc/svc.h>		/* RPCSVC_MAXPAYLOAD */
 
 #define RDMA_RESOLVE_TIMEOUT	(5000)	/* 5 seconds */
 #define RDMA_CONNECT_RETRY_MAX	(2)	/* retries if no listener backlog */
@@ -62,14 +61,12 @@
 struct rpcrdma_ia {
 	const struct rpcrdma_memreg_ops	*ri_ops;
 	rwlock_t		ri_qplock;
+	struct ib_device	*ri_device;
 	struct rdma_cm_id 	*ri_id;
 	struct ib_pd		*ri_pd;
-	struct ib_mr		*ri_bind_mem;
-	u32			ri_dma_lkey;
-	int			ri_have_dma_lkey;
+	struct ib_mr		*ri_dma_mr;
 	struct completion	ri_done;
 	int			ri_async_rc;
-	enum rpcrdma_memreg	ri_memreg_strategy;
 	unsigned int		ri_max_frmr_depth;
 	struct ib_device_attr	ri_devattr;
 	struct ib_qp_attr	ri_qp_attr;
@@ -80,21 +77,15 @@ struct rpcrdma_ia {
  * RDMA Endpoint -- one per transport instance
  */
 
-#define RPCRDMA_WC_BUDGET	(128)
-#define RPCRDMA_POLLSIZE	(16)
-
 struct rpcrdma_ep {
 	atomic_t		rep_cqcount;
 	int			rep_cqinit;
 	int			rep_connected;
 	struct ib_qp_init_attr	rep_attr;
 	wait_queue_head_t 	rep_connect_wait;
-	struct rpcrdma_regbuf	*rep_padbuf;
 	struct rdma_conn_param	rep_remote_cma;
 	struct sockaddr_storage	rep_remote_addr;
 	struct delayed_work	rep_connect_worker;
-	struct ib_wc		rep_send_wcs[RPCRDMA_POLLSIZE];
-	struct ib_wc		rep_recv_wcs[RPCRDMA_POLLSIZE];
 };
 
 /*
@@ -110,6 +101,16 @@ struct rpcrdma_ep {
  */
 #define RPCRDMA_IGNORE_COMPLETION	(0ULL)
 
+/* Pre-allocate extra Work Requests for handling backward receives
+ * and sends. This is a fixed value because the Work Queues are
+ * allocated when the forward channel is set up.
+ */
+#if defined(CONFIG_SUNRPC_BACKCHANNEL)
+#define RPCRDMA_BACKWARD_WRS		(8)
+#else
+#define RPCRDMA_BACKWARD_WRS		(0)
+#endif
+
 /* Registered buffer -- registered kmalloc'd memory for RDMA SEND/RECV
  *
  * The below structure appears at the front of a large region of kmalloc'd
@@ -119,7 +120,6 @@ struct rpcrdma_ep {
 struct rpcrdma_regbuf {
 	size_t			rg_size;
 	struct rpcrdma_req	*rg_owner;
-	struct ib_mr		*rg_mr;
 	struct ib_sge		rg_iov;
 	__be32			rg_base[0] __attribute__ ((aligned(256)));
 };
@@ -165,21 +165,22 @@ rdmab_to_msg(struct rpcrdma_regbuf *rb)
  * struct rpcrdma_buffer. N is the max number of outstanding requests.
  */
 
-/* temporary static scatter/gather max */
-#define RPCRDMA_MAX_DATA_SEGS	(64)	/* max scatter/gather */
+#define RPCRDMA_MAX_DATA_SEGS	((1 * 1024 * 1024) / PAGE_SIZE)
 #define RPCRDMA_MAX_SEGS 	(RPCRDMA_MAX_DATA_SEGS + 2) /* head+tail = 2 */
 
 struct rpcrdma_buffer;
 
 struct rpcrdma_rep {
 	unsigned int		rr_len;
-	struct rpcrdma_buffer	*rr_buffer;
-	struct rpc_xprt		*rr_xprt;
-	void			(*rr_func)(struct rpcrdma_rep *);
+	struct ib_device	*rr_device;
+	struct rpcrdma_xprt	*rr_rxprt;
+	struct work_struct	rr_work;
 	struct list_head	rr_list;
 	struct rpcrdma_regbuf	*rr_rdmabuf;
 };
 
+#define RPCRDMA_BAD_LEN		(~0U)
+
 /*
  * struct rpcrdma_mw - external memory region metadata
  *
@@ -200,14 +201,22 @@ enum rpcrdma_frmr_state {
 };
 
 struct rpcrdma_frmr {
-	struct ib_fast_reg_page_list	*fr_pgl;
+	struct scatterlist		*sg;
+	int				sg_nents;
 	struct ib_mr			*fr_mr;
 	enum rpcrdma_frmr_state		fr_state;
+	struct work_struct		fr_work;
+	struct rpcrdma_xprt		*fr_xprt;
+};
+
+struct rpcrdma_fmr {
+	struct ib_fmr		*fmr;
+	u64			*physaddrs;
 };
 
 struct rpcrdma_mw {
 	union {
-		struct ib_fmr		*fmr;
+		struct rpcrdma_fmr	fmr;
 		struct rpcrdma_frmr	frmr;
 	} r;
 	void			(*mw_sendcompletion)(struct ib_wc *);
@@ -252,16 +261,22 @@ struct rpcrdma_mr_seg {		/* chunk descriptors */
 	char		*mr_offset;	/* kva if no page, else offset */
 };
 
+#define RPCRDMA_MAX_IOVS	(2)
+
 struct rpcrdma_req {
-	unsigned int	rl_niovs;	/* 0, 2 or 4 */
-	unsigned int	rl_nchunks;	/* non-zero if chunks */
-	unsigned int	rl_connect_cookie;	/* retry detection */
-	struct rpcrdma_buffer *rl_buffer; /* home base for this structure */
+	struct list_head	rl_free;
+	unsigned int		rl_niovs;
+	unsigned int		rl_nchunks;
+	unsigned int		rl_connect_cookie;
+	struct rpcrdma_buffer	*rl_buffer;
 	struct rpcrdma_rep	*rl_reply;/* holder for reply buffer */
-	struct ib_sge	rl_send_iov[4];	/* for active requests */
-	struct rpcrdma_regbuf *rl_rdmabuf;
-	struct rpcrdma_regbuf *rl_sendbuf;
-	struct rpcrdma_mr_seg rl_segments[RPCRDMA_MAX_SEGS];
+	struct ib_sge		rl_send_iov[RPCRDMA_MAX_IOVS];
+	struct rpcrdma_regbuf	*rl_rdmabuf;
+	struct rpcrdma_regbuf	*rl_sendbuf;
+	struct rpcrdma_mr_seg	rl_segments[RPCRDMA_MAX_SEGS];
+
+	struct list_head	rl_all;
+	bool			rl_backchannel;
 };
 
 static inline struct rpcrdma_req *
@@ -281,15 +296,19 @@ rpcr_to_rdmar(struct rpc_rqst *rqst)
  * One of these is associated with a transport instance
  */
 struct rpcrdma_buffer {
-	spinlock_t	rb_lock;	/* protects indexes */
-	u32		rb_max_requests;/* client max requests */
-	struct list_head rb_mws;	/* optional memory windows/fmrs/frmrs */
-	struct list_head rb_all;
-	int		rb_send_index;
-	struct rpcrdma_req	**rb_send_bufs;
-	int		rb_recv_index;
-	struct rpcrdma_rep	**rb_recv_bufs;
-	char		*rb_pool;
+	spinlock_t		rb_mwlock;	/* protect rb_mws list */
+	struct list_head	rb_mws;
+	struct list_head	rb_all;
+	char			*rb_pool;
+
+	spinlock_t		rb_lock;	/* protect buf lists */
+	struct list_head	rb_send_bufs;
+	struct list_head	rb_recv_bufs;
+	u32			rb_max_requests;
+
+	u32			rb_bc_srv_max_requests;
+	spinlock_t		rb_reqslock;	/* protect rb_allreqs */
+	struct list_head	rb_allreqs;
 };
 #define rdmab_to_ia(b) (&container_of((b), struct rpcrdma_xprt, rx_buf)->rx_ia)
 
@@ -334,6 +353,8 @@ struct rpcrdma_stats {
 	unsigned long		hardway_register_count;
 	unsigned long		failed_marshal_count;
 	unsigned long		bad_reply_count;
+	unsigned long		nomsg_call_count;
+	unsigned long		bcall_count;
 };
 
 /*
@@ -350,7 +371,6 @@ struct rpcrdma_memreg_ops {
 				   struct rpcrdma_create_data_internal *);
 	size_t		(*ro_maxpages)(struct rpcrdma_xprt *);
 	int		(*ro_init)(struct rpcrdma_xprt *);
-	void		(*ro_reset)(struct rpcrdma_xprt *);
 	void		(*ro_destroy)(struct rpcrdma_buffer *);
 	const char	*ro_displayname;
 };
@@ -410,9 +430,14 @@ int rpcrdma_ep_post_recv(struct rpcrdma_ia *, struct rpcrdma_ep *,
 /*
  * Buffer calls - xprtrdma/verbs.c
  */
+struct rpcrdma_req *rpcrdma_create_req(struct rpcrdma_xprt *);
+struct rpcrdma_rep *rpcrdma_create_rep(struct rpcrdma_xprt *);
+void rpcrdma_destroy_req(struct rpcrdma_ia *, struct rpcrdma_req *);
 int rpcrdma_buffer_create(struct rpcrdma_xprt *);
 void rpcrdma_buffer_destroy(struct rpcrdma_buffer *);
 
+struct rpcrdma_mw *rpcrdma_get_mw(struct rpcrdma_xprt *);
+void rpcrdma_put_mw(struct rpcrdma_xprt *, struct rpcrdma_mw *);
 struct rpcrdma_req *rpcrdma_buffer_get(struct rpcrdma_buffer *);
 void rpcrdma_buffer_put(struct rpcrdma_req *);
 void rpcrdma_recv_buffer_get(struct rpcrdma_req *);
@@ -424,6 +449,13 @@ void rpcrdma_free_regbuf(struct rpcrdma_ia *,
 			 struct rpcrdma_regbuf *);
 
 unsigned int rpcrdma_max_segments(struct rpcrdma_xprt *);
+int rpcrdma_ep_post_extra_recv(struct rpcrdma_xprt *, unsigned int);
+
+int frwr_alloc_recovery_wq(void);
+void frwr_destroy_recovery_wq(void);
+
+int rpcrdma_alloc_wq(void);
+void rpcrdma_destroy_wq(void);
 
 /*
  * Wrappers for chunk registration, shared by read/write chunk code.
@@ -480,6 +512,23 @@ void rpcrdma_reply_handler(struct rpcrdma_rep *);
  */
 int rpcrdma_marshal_req(struct rpc_rqst *);
 
+/* RPC/RDMA module init - xprtrdma/transport.c
+ */
+int xprt_rdma_init(void);
+void xprt_rdma_cleanup(void);
+
+/* Backchannel calls - xprtrdma/backchannel.c
+ */
+#if defined(CONFIG_SUNRPC_BACKCHANNEL)
+int xprt_rdma_bc_setup(struct rpc_xprt *, unsigned int);
+int xprt_rdma_bc_up(struct svc_serv *, struct net *);
+int rpcrdma_bc_post_recv(struct rpcrdma_xprt *, unsigned int);
+void rpcrdma_bc_receive_call(struct rpcrdma_xprt *, struct rpcrdma_rep *);
+int rpcrdma_bc_marshal_reply(struct rpc_rqst *);
+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  */
@@ -487,10 +536,4 @@ extern struct kmem_cache *svc_rdma_ctxt_cachep;
 /* Workqueue created in svc_rdma.c */
 extern struct workqueue_struct *svc_rdma_wq;
 
-#if RPCSVC_MAXPAYLOAD < (RPCRDMA_MAX_DATA_SEGS << PAGE_SHIFT)
-#define RPCSVC_MAXPAYLOAD_RDMA RPCSVC_MAXPAYLOAD
-#else
-#define RPCSVC_MAXPAYLOAD_RDMA (RPCRDMA_MAX_DATA_SEGS << PAGE_SHIFT)
-#endif
-
 #endif				/* _LINUX_SUNRPC_XPRT_RDMA_H */
diff --git a/kernel/net/sunrpc/xprtsock.c b/kernel/net/sunrpc/xprtsock.c
index 5e3ad598d..027c9ef8a 100644
--- a/kernel/net/sunrpc/xprtsock.c
+++ b/kernel/net/sunrpc/xprtsock.c
@@ -360,8 +360,10 @@ static int xs_send_pagedata(struct socket *sock, struct xdr_buf *xdr, unsigned i
 		int flags = XS_SENDMSG_FLAGS;
 
 		remainder -= len;
-		if (remainder != 0 || more)
+		if (more)
 			flags |= MSG_MORE;
+		if (remainder != 0)
+			flags |= MSG_SENDPAGE_NOTLAST | MSG_MORE;
 		err = do_sendpage(sock, *ppage, base, len, flags);
 		if (remainder == 0 || err != len)
 			break;
@@ -396,7 +398,6 @@ static int xs_sendpages(struct socket *sock, struct sockaddr *addr, int addrlen,
 	if (unlikely(!sock))
 		return -ENOTSOCK;
 
-	clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags);
 	if (base != 0) {
 		addr = NULL;
 		addrlen = 0;
@@ -440,7 +441,6 @@ static void xs_nospace_callback(struct rpc_task *task)
 	struct sock_xprt *transport = container_of(task->tk_rqstp->rq_xprt, struct sock_xprt, xprt);
 
 	transport->inet->sk_write_pending--;
-	clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
 }
 
 /**
@@ -465,20 +465,11 @@ static int xs_nospace(struct rpc_task *task)
 
 	/* Don't race with disconnect */
 	if (xprt_connected(xprt)) {
-		if (test_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags)) {
-			/*
-			 * Notify TCP that we're limited by the application
-			 * window size
-			 */
-			set_bit(SOCK_NOSPACE, &transport->sock->flags);
-			sk->sk_write_pending++;
-			/* ...and wait for more buffer space */
-			xprt_wait_for_buffer_space(task, xs_nospace_callback);
-		}
-	} else {
-		clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
+		/* wait for more buffer space */
+		sk->sk_write_pending++;
+		xprt_wait_for_buffer_space(task, xs_nospace_callback);
+	} else
 		ret = -ENOTCONN;
-	}
 
 	spin_unlock_bh(&xprt->transport_lock);
 
@@ -527,6 +518,10 @@ static int xs_local_send_request(struct rpc_task *task)
 			      true, &sent);
 	dprintk("RPC:       %s(%u) = %d\n",
 			__func__, xdr->len - req->rq_bytes_sent, status);
+
+	if (status == -EAGAIN && sock_writeable(transport->inet))
+		status = -ENOBUFS;
+
 	if (likely(sent > 0) || status == 0) {
 		req->rq_bytes_sent += sent;
 		req->rq_xmit_bytes_sent += sent;
@@ -539,6 +534,7 @@ static int xs_local_send_request(struct rpc_task *task)
 
 	switch (status) {
 	case -ENOBUFS:
+		break;
 	case -EAGAIN:
 		status = xs_nospace(task);
 		break;
@@ -589,6 +585,9 @@ static int xs_udp_send_request(struct rpc_task *task)
 	if (status == -EPERM)
 		goto process_status;
 
+	if (status == -EAGAIN && sock_writeable(transport->inet))
+		status = -ENOBUFS;
+
 	if (sent > 0 || status == 0) {
 		req->rq_xmit_bytes_sent += sent;
 		if (sent >= req->rq_slen)
@@ -606,9 +605,6 @@ process_status:
 	case -EAGAIN:
 		status = xs_nospace(task);
 		break;
-	default:
-		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
-			-status);
 	case -ENETUNREACH:
 	case -ENOBUFS:
 	case -EPIPE:
@@ -616,31 +612,16 @@ process_status:
 	case -EPERM:
 		/* When the server has died, an ICMP port unreachable message
 		 * prompts ECONNREFUSED. */
-		clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
+		break;
+	default:
+		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
+			-status);
 	}
 
 	return status;
 }
 
 /**
- * xs_tcp_shutdown - gracefully shut down a TCP socket
- * @xprt: transport
- *
- * Initiates a graceful shutdown of the TCP socket by calling the
- * equivalent of shutdown(SHUT_RDWR);
- */
-static void xs_tcp_shutdown(struct rpc_xprt *xprt)
-{
-	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
-	struct socket *sock = transport->sock;
-
-	if (sock != NULL) {
-		kernel_sock_shutdown(sock, SHUT_RDWR);
-		trace_rpc_socket_shutdown(xprt, sock);
-	}
-}
-
-/**
  * xs_tcp_send_request - write an RPC request to a TCP socket
  * @task: address of RPC task that manages the state of an RPC request
  *
@@ -687,9 +668,6 @@ static int xs_tcp_send_request(struct rpc_task *task)
 		dprintk("RPC:       xs_tcp_send_request(%u) = %d\n",
 				xdr->len - req->rq_bytes_sent, status);
 
-		if (unlikely(sent == 0 && status < 0))
-			break;
-
 		/* If we've sent the entire packet, immediately
 		 * reset the count of bytes sent. */
 		req->rq_bytes_sent += sent;
@@ -699,30 +677,34 @@ static int xs_tcp_send_request(struct rpc_task *task)
 			return 0;
 		}
 
-		if (sent != 0)
-			continue;
-		status = -EAGAIN;
-		break;
+		if (status < 0)
+			break;
+		if (sent == 0) {
+			status = -EAGAIN;
+			break;
+		}
 	}
+	if (status == -EAGAIN && sk_stream_is_writeable(transport->inet))
+		status = -ENOBUFS;
 
 	switch (status) {
 	case -ENOTSOCK:
 		status = -ENOTCONN;
 		/* Should we call xs_close() here? */
 		break;
-	case -ENOBUFS:
 	case -EAGAIN:
 		status = xs_nospace(task);
 		break;
-	default:
-		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
-			-status);
 	case -ECONNRESET:
 	case -ECONNREFUSED:
 	case -ENOTCONN:
 	case -EADDRINUSE:
+	case -ENOBUFS:
 	case -EPIPE:
-		clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
+		break;
+	default:
+		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
+			-status);
 	}
 
 	return status;
@@ -827,6 +809,12 @@ static void xs_reset_transport(struct sock_xprt *transport)
 	if (sk == NULL)
 		return;
 
+	if (atomic_read(&transport->xprt.swapper))
+		sk_clear_memalloc(sk);
+
+	kernel_sock_shutdown(sock, SHUT_RDWR);
+
+	mutex_lock(&transport->recv_mutex);
 	write_lock_bh(&sk->sk_callback_lock);
 	transport->inet = NULL;
 	transport->sock = NULL;
@@ -837,6 +825,7 @@ static void xs_reset_transport(struct sock_xprt *transport)
 	xprt_clear_connected(xprt);
 	write_unlock_bh(&sk->sk_callback_lock);
 	xs_sock_reset_connection_flags(xprt);
+	mutex_unlock(&transport->recv_mutex);
 
 	trace_rpc_socket_close(xprt, sock);
 	sock_release(sock);
@@ -864,6 +853,13 @@ static void xs_close(struct rpc_xprt *xprt)
 	xprt_disconnect_done(xprt);
 }
 
+static void xs_inject_disconnect(struct rpc_xprt *xprt)
+{
+	dprintk("RPC:       injecting transport disconnect on xprt=%p\n",
+		xprt);
+	xprt_disconnect_done(xprt);
+}
+
 static void xs_xprt_free(struct rpc_xprt *xprt)
 {
 	xs_free_peer_addresses(xprt);
@@ -877,9 +873,13 @@ static void xs_xprt_free(struct rpc_xprt *xprt)
  */
 static void xs_destroy(struct rpc_xprt *xprt)
 {
+	struct sock_xprt *transport = container_of(xprt,
+			struct sock_xprt, xprt);
 	dprintk("RPC:       xs_destroy xprt %p\n", xprt);
 
+	cancel_delayed_work_sync(&transport->connect_worker);
 	xs_close(xprt);
+	cancel_work_sync(&transport->recv_worker);
 	xs_xprt_free(xprt);
 	module_put(THIS_MODULE);
 }
@@ -900,45 +900,36 @@ static int xs_local_copy_to_xdr(struct xdr_buf *xdr, struct sk_buff *skb)
 }
 
 /**
- * xs_local_data_ready - "data ready" callback for AF_LOCAL sockets
- * @sk: socket with data to read
- * @len: how much data to read
+ * xs_local_data_read_skb
+ * @xprt: transport
+ * @sk: socket
+ * @skb: skbuff
  *
  * Currently this assumes we can read the whole reply in a single gulp.
  */
-static void xs_local_data_ready(struct sock *sk)
+static void xs_local_data_read_skb(struct rpc_xprt *xprt,
+		struct sock *sk,
+		struct sk_buff *skb)
 {
 	struct rpc_task *task;
-	struct rpc_xprt *xprt;
 	struct rpc_rqst *rovr;
-	struct sk_buff *skb;
-	int err, repsize, copied;
+	int repsize, copied;
 	u32 _xid;
 	__be32 *xp;
 
-	read_lock_bh(&sk->sk_callback_lock);
-	dprintk("RPC:       %s...\n", __func__);
-	xprt = xprt_from_sock(sk);
-	if (xprt == NULL)
-		goto out;
-
-	skb = skb_recv_datagram(sk, 0, 1, &err);
-	if (skb == NULL)
-		goto out;
-
 	repsize = skb->len - sizeof(rpc_fraghdr);
 	if (repsize < 4) {
 		dprintk("RPC:       impossible RPC reply size %d\n", repsize);
-		goto dropit;
+		return;
 	}
 
 	/* Copy the XID from the skb... */
 	xp = skb_header_pointer(skb, sizeof(rpc_fraghdr), sizeof(_xid), &_xid);
 	if (xp == NULL)
-		goto dropit;
+		return;
 
 	/* Look up and lock the request corresponding to the given XID */
-	spin_lock(&xprt->transport_lock);
+	spin_lock_bh(&xprt->transport_lock);
 	rovr = xprt_lookup_rqst(xprt, *xp);
 	if (!rovr)
 		goto out_unlock;
@@ -956,51 +947,68 @@ static void xs_local_data_ready(struct sock *sk)
 	xprt_complete_rqst(task, copied);
 
  out_unlock:
-	spin_unlock(&xprt->transport_lock);
- dropit:
-	skb_free_datagram(sk, skb);
- out:
-	read_unlock_bh(&sk->sk_callback_lock);
+	spin_unlock_bh(&xprt->transport_lock);
+}
+
+static void xs_local_data_receive(struct sock_xprt *transport)
+{
+	struct sk_buff *skb;
+	struct sock *sk;
+	int err;
+
+	mutex_lock(&transport->recv_mutex);
+	sk = transport->inet;
+	if (sk == NULL)
+		goto out;
+	for (;;) {
+		skb = skb_recv_datagram(sk, 0, 1, &err);
+		if (skb == NULL)
+			break;
+		xs_local_data_read_skb(&transport->xprt, sk, skb);
+		skb_free_datagram(sk, skb);
+	}
+out:
+	mutex_unlock(&transport->recv_mutex);
+}
+
+static void xs_local_data_receive_workfn(struct work_struct *work)
+{
+	struct sock_xprt *transport =
+		container_of(work, struct sock_xprt, recv_worker);
+	xs_local_data_receive(transport);
 }
 
 /**
- * xs_udp_data_ready - "data ready" callback for UDP sockets
- * @sk: socket with data to read
- * @len: how much data to read
+ * xs_udp_data_read_skb - receive callback for UDP sockets
+ * @xprt: transport
+ * @sk: socket
+ * @skb: skbuff
  *
  */
-static void xs_udp_data_ready(struct sock *sk)
+static void xs_udp_data_read_skb(struct rpc_xprt *xprt,
+		struct sock *sk,
+		struct sk_buff *skb)
 {
 	struct rpc_task *task;
-	struct rpc_xprt *xprt;
 	struct rpc_rqst *rovr;
-	struct sk_buff *skb;
-	int err, repsize, copied;
+	int repsize, copied;
 	u32 _xid;
 	__be32 *xp;
 
-	read_lock_bh(&sk->sk_callback_lock);
-	dprintk("RPC:       xs_udp_data_ready...\n");
-	if (!(xprt = xprt_from_sock(sk)))
-		goto out;
-
-	if ((skb = skb_recv_datagram(sk, 0, 1, &err)) == NULL)
-		goto out;
-
 	repsize = skb->len - sizeof(struct udphdr);
 	if (repsize < 4) {
 		dprintk("RPC:       impossible RPC reply size %d!\n", repsize);
-		goto dropit;
+		return;
 	}
 
 	/* Copy the XID from the skb... */
 	xp = skb_header_pointer(skb, sizeof(struct udphdr),
 				sizeof(_xid), &_xid);
 	if (xp == NULL)
-		goto dropit;
+		return;
 
 	/* Look up and lock the request corresponding to the given XID */
-	spin_lock(&xprt->transport_lock);
+	spin_lock_bh(&xprt->transport_lock);
 	rovr = xprt_lookup_rqst(xprt, *xp);
 	if (!rovr)
 		goto out_unlock;
@@ -1021,10 +1029,54 @@ static void xs_udp_data_ready(struct sock *sk)
 	xprt_complete_rqst(task, copied);
 
  out_unlock:
-	spin_unlock(&xprt->transport_lock);
- dropit:
-	skb_free_datagram(sk, skb);
- out:
+	spin_unlock_bh(&xprt->transport_lock);
+}
+
+static void xs_udp_data_receive(struct sock_xprt *transport)
+{
+	struct sk_buff *skb;
+	struct sock *sk;
+	int err;
+
+	mutex_lock(&transport->recv_mutex);
+	sk = transport->inet;
+	if (sk == NULL)
+		goto out;
+	for (;;) {
+		skb = skb_recv_datagram(sk, 0, 1, &err);
+		if (skb == NULL)
+			break;
+		xs_udp_data_read_skb(&transport->xprt, sk, skb);
+		skb_free_datagram(sk, skb);
+	}
+out:
+	mutex_unlock(&transport->recv_mutex);
+}
+
+static void xs_udp_data_receive_workfn(struct work_struct *work)
+{
+	struct sock_xprt *transport =
+		container_of(work, struct sock_xprt, recv_worker);
+	xs_udp_data_receive(transport);
+}
+
+/**
+ * xs_data_ready - "data ready" callback for UDP sockets
+ * @sk: socket with data to read
+ *
+ */
+static void xs_data_ready(struct sock *sk)
+{
+	struct rpc_xprt *xprt;
+
+	read_lock_bh(&sk->sk_callback_lock);
+	dprintk("RPC:       xs_data_ready...\n");
+	xprt = xprt_from_sock(sk);
+	if (xprt != NULL) {
+		struct sock_xprt *transport = container_of(xprt,
+				struct sock_xprt, xprt);
+		queue_work(rpciod_workqueue, &transport->recv_worker);
+	}
 	read_unlock_bh(&sk->sk_callback_lock);
 }
 
@@ -1239,12 +1291,12 @@ static inline int xs_tcp_read_reply(struct rpc_xprt *xprt,
 	dprintk("RPC:       read reply XID %08x\n", ntohl(transport->tcp_xid));
 
 	/* Find and lock the request corresponding to this xid */
-	spin_lock(&xprt->transport_lock);
+	spin_lock_bh(&xprt->transport_lock);
 	req = xprt_lookup_rqst(xprt, transport->tcp_xid);
 	if (!req) {
 		dprintk("RPC:       XID %08x request not found!\n",
 				ntohl(transport->tcp_xid));
-		spin_unlock(&xprt->transport_lock);
+		spin_unlock_bh(&xprt->transport_lock);
 		return -1;
 	}
 
@@ -1253,7 +1305,7 @@ static inline int xs_tcp_read_reply(struct rpc_xprt *xprt,
 	if (!(transport->tcp_flags & TCP_RCV_COPY_DATA))
 		xprt_complete_rqst(req->rq_task, transport->tcp_copied);
 
-	spin_unlock(&xprt->transport_lock);
+	spin_unlock_bh(&xprt->transport_lock);
 	return 0;
 }
 
@@ -1273,10 +1325,10 @@ static int xs_tcp_read_callback(struct rpc_xprt *xprt,
 	struct rpc_rqst *req;
 
 	/* Look up and lock the request corresponding to the given XID */
-	spin_lock(&xprt->transport_lock);
+	spin_lock_bh(&xprt->transport_lock);
 	req = xprt_lookup_bc_request(xprt, transport->tcp_xid);
 	if (req == NULL) {
-		spin_unlock(&xprt->transport_lock);
+		spin_unlock_bh(&xprt->transport_lock);
 		printk(KERN_WARNING "Callback slot table overflowed\n");
 		xprt_force_disconnect(xprt);
 		return -1;
@@ -1287,7 +1339,7 @@ static int xs_tcp_read_callback(struct rpc_xprt *xprt,
 
 	if (!(transport->tcp_flags & TCP_RCV_COPY_DATA))
 		xprt_complete_bc_request(req, transport->tcp_copied);
-	spin_unlock(&xprt->transport_lock);
+	spin_unlock_bh(&xprt->transport_lock);
 
 	return 0;
 }
@@ -1302,6 +1354,17 @@ static inline int _xs_tcp_read_data(struct rpc_xprt *xprt,
 		xs_tcp_read_reply(xprt, desc) :
 		xs_tcp_read_callback(xprt, desc);
 }
+
+static int xs_tcp_bc_up(struct svc_serv *serv, struct net *net)
+{
+	int ret;
+
+	ret = svc_create_xprt(serv, "tcp-bc", net, PF_INET, 0,
+			      SVC_SOCK_ANONYMOUS);
+	if (ret < 0)
+		return ret;
+	return 0;
+}
 #else
 static inline int _xs_tcp_read_data(struct rpc_xprt *xprt,
 					struct xdr_skb_reader *desc)
@@ -1387,42 +1450,69 @@ static int xs_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, uns
 	return len - desc.count;
 }
 
+static void xs_tcp_data_receive(struct sock_xprt *transport)
+{
+	struct rpc_xprt *xprt = &transport->xprt;
+	struct sock *sk;
+	read_descriptor_t rd_desc = {
+		.count = 2*1024*1024,
+		.arg.data = xprt,
+	};
+	unsigned long total = 0;
+	int read = 0;
+
+	mutex_lock(&transport->recv_mutex);
+	sk = transport->inet;
+	if (sk == NULL)
+		goto out;
+
+	/* We use rd_desc to pass struct xprt to xs_tcp_data_recv */
+	for (;;) {
+		lock_sock(sk);
+		read = tcp_read_sock(sk, &rd_desc, xs_tcp_data_recv);
+		release_sock(sk);
+		if (read <= 0)
+			break;
+		total += read;
+		rd_desc.count = 65536;
+	}
+out:
+	mutex_unlock(&transport->recv_mutex);
+	trace_xs_tcp_data_ready(xprt, read, total);
+}
+
+static void xs_tcp_data_receive_workfn(struct work_struct *work)
+{
+	struct sock_xprt *transport =
+		container_of(work, struct sock_xprt, recv_worker);
+	xs_tcp_data_receive(transport);
+}
+
 /**
  * xs_tcp_data_ready - "data ready" callback for TCP sockets
  * @sk: socket with data to read
- * @bytes: how much data to read
  *
  */
 static void xs_tcp_data_ready(struct sock *sk)
 {
+	struct sock_xprt *transport;
 	struct rpc_xprt *xprt;
-	read_descriptor_t rd_desc;
-	int read;
-	unsigned long total = 0;
 
 	dprintk("RPC:       xs_tcp_data_ready...\n");
 
 	read_lock_bh(&sk->sk_callback_lock);
-	if (!(xprt = xprt_from_sock(sk))) {
-		read = 0;
+	if (!(xprt = xprt_from_sock(sk)))
 		goto out;
-	}
+	transport = container_of(xprt, struct sock_xprt, xprt);
+
 	/* Any data means we had a useful conversation, so
 	 * the we don't need to delay the next reconnect
 	 */
 	if (xprt->reestablish_timeout)
 		xprt->reestablish_timeout = 0;
+	queue_work(rpciod_workqueue, &transport->recv_worker);
 
-	/* We use rd_desc to pass struct xprt to xs_tcp_data_recv */
-	rd_desc.arg.data = xprt;
-	do {
-		rd_desc.count = 65536;
-		read = tcp_read_sock(sk, &rd_desc, xs_tcp_data_recv);
-		if (read > 0)
-			total += read;
-	} while (read > 0);
 out:
-	trace_xs_tcp_data_ready(xprt, read, total);
 	read_unlock_bh(&sk->sk_callback_lock);
 }
 
@@ -1508,19 +1598,23 @@ static void xs_tcp_state_change(struct sock *sk)
 
 static void xs_write_space(struct sock *sk)
 {
-	struct socket *sock;
+	struct socket_wq *wq;
 	struct rpc_xprt *xprt;
 
-	if (unlikely(!(sock = sk->sk_socket)))
+	if (!sk->sk_socket)
 		return;
-	clear_bit(SOCK_NOSPACE, &sock->flags);
+	clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
 
 	if (unlikely(!(xprt = xprt_from_sock(sk))))
 		return;
-	if (test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags) == 0)
-		return;
+	rcu_read_lock();
+	wq = rcu_dereference(sk->sk_wq);
+	if (!wq || test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags) == 0)
+		goto out;
 
 	xprt_write_space(xprt);
+out:
+	rcu_read_unlock();
 }
 
 /**
@@ -1870,10 +1964,10 @@ static int xs_local_finish_connecting(struct rpc_xprt *xprt,
 		xs_save_old_callbacks(transport, sk);
 
 		sk->sk_user_data = xprt;
-		sk->sk_data_ready = xs_local_data_ready;
+		sk->sk_data_ready = xs_data_ready;
 		sk->sk_write_space = xs_udp_write_space;
 		sk->sk_error_report = xs_error_report;
-		sk->sk_allocation = GFP_ATOMIC;
+		sk->sk_allocation = GFP_NOIO;
 
 		xprt_clear_connected(xprt);
 
@@ -1892,9 +1986,7 @@ static int xs_local_finish_connecting(struct rpc_xprt *xprt,
 
 /**
  * xs_local_setup_socket - create AF_LOCAL socket, connect to a local endpoint
- * @xprt: RPC transport to connect
  * @transport: socket transport to connect
- * @create_sock: function to create a socket of the correct type
  */
 static int xs_local_setup_socket(struct sock_xprt *transport)
 {
@@ -1966,43 +2058,84 @@ static void xs_local_connect(struct rpc_xprt *xprt, struct rpc_task *task)
 		msleep_interruptible(15000);
 }
 
-#ifdef CONFIG_SUNRPC_SWAP
+#if IS_ENABLED(CONFIG_SUNRPC_SWAP)
+/*
+ * Note that this should be called with XPRT_LOCKED held (or when we otherwise
+ * know that we have exclusive access to the socket), to guard against
+ * races with xs_reset_transport.
+ */
 static void xs_set_memalloc(struct rpc_xprt *xprt)
 {
 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
 			xprt);
 
-	if (xprt->swapper)
+	/*
+	 * If there's no sock, then we have nothing to set. The
+	 * reconnecting process will get it for us.
+	 */
+	if (!transport->inet)
+		return;
+	if (atomic_read(&xprt->swapper))
 		sk_set_memalloc(transport->inet);
 }
 
 /**
- * xs_swapper - Tag this transport as being used for swap.
+ * xs_enable_swap - Tag this transport as being used for swap.
  * @xprt: transport to tag
- * @enable: enable/disable
  *
+ * Take a reference to this transport on behalf of the rpc_clnt, and
+ * optionally mark it for swapping if it wasn't already.
  */
-int xs_swapper(struct rpc_xprt *xprt, int enable)
+static int
+xs_enable_swap(struct rpc_xprt *xprt)
 {
-	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
-			xprt);
-	int err = 0;
+	struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
 
-	if (enable) {
-		xprt->swapper++;
-		xs_set_memalloc(xprt);
-	} else if (xprt->swapper) {
-		xprt->swapper--;
-		sk_clear_memalloc(transport->inet);
-	}
+	if (atomic_inc_return(&xprt->swapper) != 1)
+		return 0;
+	if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
+		return -ERESTARTSYS;
+	if (xs->inet)
+		sk_set_memalloc(xs->inet);
+	xprt_release_xprt(xprt, NULL);
+	return 0;
+}
 
-	return err;
+/**
+ * xs_disable_swap - Untag this transport as being used for swap.
+ * @xprt: transport to tag
+ *
+ * Drop a "swapper" reference to this xprt on behalf of the rpc_clnt. If the
+ * swapper refcount goes to 0, untag the socket as a memalloc socket.
+ */
+static void
+xs_disable_swap(struct rpc_xprt *xprt)
+{
+	struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
+
+	if (!atomic_dec_and_test(&xprt->swapper))
+		return;
+	if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
+		return;
+	if (xs->inet)
+		sk_clear_memalloc(xs->inet);
+	xprt_release_xprt(xprt, NULL);
 }
-EXPORT_SYMBOL_GPL(xs_swapper);
 #else
 static void xs_set_memalloc(struct rpc_xprt *xprt)
 {
 }
+
+static int
+xs_enable_swap(struct rpc_xprt *xprt)
+{
+	return -EINVAL;
+}
+
+static void
+xs_disable_swap(struct rpc_xprt *xprt)
+{
+}
 #endif
 
 static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
@@ -2017,9 +2150,9 @@ static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
 		xs_save_old_callbacks(transport, sk);
 
 		sk->sk_user_data = xprt;
-		sk->sk_data_ready = xs_udp_data_ready;
+		sk->sk_data_ready = xs_data_ready;
 		sk->sk_write_space = xs_udp_write_space;
-		sk->sk_allocation = GFP_ATOMIC;
+		sk->sk_allocation = GFP_NOIO;
 
 		xprt_set_connected(xprt);
 
@@ -2063,6 +2196,27 @@ out:
 	xprt_wake_pending_tasks(xprt, status);
 }
 
+/**
+ * xs_tcp_shutdown - gracefully shut down a TCP socket
+ * @xprt: transport
+ *
+ * Initiates a graceful shutdown of the TCP socket by calling the
+ * equivalent of shutdown(SHUT_RDWR);
+ */
+static void xs_tcp_shutdown(struct rpc_xprt *xprt)
+{
+	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
+	struct socket *sock = transport->sock;
+
+	if (sock == NULL)
+		return;
+	if (xprt_connected(xprt)) {
+		kernel_sock_shutdown(sock, SHUT_RDWR);
+		trace_rpc_socket_shutdown(xprt, sock);
+	} else
+		xs_reset_transport(transport);
+}
+
 static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
 {
 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
@@ -2073,6 +2227,7 @@ static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
 		unsigned int keepidle = xprt->timeout->to_initval / HZ;
 		unsigned int keepcnt = xprt->timeout->to_retries + 1;
 		unsigned int opt_on = 1;
+		unsigned int timeo;
 
 		/* TCP Keepalive options */
 		kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
@@ -2084,6 +2239,12 @@ static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
 		kernel_setsockopt(sock, SOL_TCP, TCP_KEEPCNT,
 				(char *)&keepcnt, sizeof(keepcnt));
 
+		/* TCP user timeout (see RFC5482) */
+		timeo = jiffies_to_msecs(xprt->timeout->to_initval) *
+			(xprt->timeout->to_retries + 1);
+		kernel_setsockopt(sock, SOL_TCP, TCP_USER_TIMEOUT,
+				(char *)&timeo, sizeof(timeo));
+
 		write_lock_bh(&sk->sk_callback_lock);
 
 		xs_save_old_callbacks(transport, sk);
@@ -2093,7 +2254,7 @@ static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
 		sk->sk_state_change = xs_tcp_state_change;
 		sk->sk_write_space = xs_tcp_write_space;
 		sk->sk_error_report = xs_error_report;
-		sk->sk_allocation = GFP_ATOMIC;
+		sk->sk_allocation = GFP_NOIO;
 
 		/* socket options */
 		sock_reset_flag(sk, SOCK_LINGER);
@@ -2132,9 +2293,6 @@ out:
 
 /**
  * xs_tcp_setup_socket - create a TCP socket and connect to a remote endpoint
- * @xprt: RPC transport to connect
- * @transport: socket transport to connect
- * @create_sock: function to create a socket of the correct type
  *
  * Invoked by a work queue tasklet.
  */
@@ -2405,7 +2563,7 @@ static int bc_send_request(struct rpc_task *task)
 {
 	struct rpc_rqst *req = task->tk_rqstp;
 	struct svc_xprt	*xprt;
-	u32                     len;
+	int len;
 
 	dprintk("sending request with xid: %08x\n", ntohl(req->rq_xid));
 	/*
@@ -2470,6 +2628,8 @@ static struct rpc_xprt_ops xs_local_ops = {
 	.close			= xs_close,
 	.destroy		= xs_destroy,
 	.print_stats		= xs_local_print_stats,
+	.enable_swap		= xs_enable_swap,
+	.disable_swap		= xs_disable_swap,
 };
 
 static struct rpc_xprt_ops xs_udp_ops = {
@@ -2489,6 +2649,9 @@ static struct rpc_xprt_ops xs_udp_ops = {
 	.close			= xs_close,
 	.destroy		= xs_destroy,
 	.print_stats		= xs_udp_print_stats,
+	.enable_swap		= xs_enable_swap,
+	.disable_swap		= xs_disable_swap,
+	.inject_disconnect	= xs_inject_disconnect,
 };
 
 static struct rpc_xprt_ops xs_tcp_ops = {
@@ -2505,6 +2668,15 @@ static struct rpc_xprt_ops xs_tcp_ops = {
 	.close			= xs_tcp_shutdown,
 	.destroy		= xs_destroy,
 	.print_stats		= xs_tcp_print_stats,
+	.enable_swap		= xs_enable_swap,
+	.disable_swap		= xs_disable_swap,
+	.inject_disconnect	= xs_inject_disconnect,
+#ifdef CONFIG_SUNRPC_BACKCHANNEL
+	.bc_setup		= xprt_setup_bc,
+	.bc_up			= xs_tcp_bc_up,
+	.bc_free_rqst		= xprt_free_bc_rqst,
+	.bc_destroy		= xprt_destroy_bc,
+#endif
 };
 
 /*
@@ -2522,6 +2694,9 @@ static struct rpc_xprt_ops bc_tcp_ops = {
 	.close			= bc_close,
 	.destroy		= bc_destroy,
 	.print_stats		= xs_tcp_print_stats,
+	.enable_swap		= xs_enable_swap,
+	.disable_swap		= xs_disable_swap,
+	.inject_disconnect	= xs_inject_disconnect,
 };
 
 static int xs_init_anyaddr(const int family, struct sockaddr *sap)
@@ -2572,6 +2747,7 @@ static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
 	}
 
 	new = container_of(xprt, struct sock_xprt, xprt);
+	mutex_init(&new->recv_mutex);
 	memcpy(&xprt->addr, args->dstaddr, args->addrlen);
 	xprt->addrlen = args->addrlen;
 	if (args->srcaddr)
@@ -2625,6 +2801,7 @@ static struct rpc_xprt *xs_setup_local(struct xprt_create *args)
 	xprt->ops = &xs_local_ops;
 	xprt->timeout = &xs_local_default_timeout;
 
+	INIT_WORK(&transport->recv_worker, xs_local_data_receive_workfn);
 	INIT_DELAYED_WORK(&transport->connect_worker,
 			xs_dummy_setup_socket);
 
@@ -2696,21 +2873,20 @@ static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
 
 	xprt->timeout = &xs_udp_default_timeout;
 
+	INIT_WORK(&transport->recv_worker, xs_udp_data_receive_workfn);
+	INIT_DELAYED_WORK(&transport->connect_worker, xs_udp_setup_socket);
+
 	switch (addr->sa_family) {
 	case AF_INET:
 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
 			xprt_set_bound(xprt);
 
-		INIT_DELAYED_WORK(&transport->connect_worker,
-					xs_udp_setup_socket);
 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP);
 		break;
 	case AF_INET6:
 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
 			xprt_set_bound(xprt);
 
-		INIT_DELAYED_WORK(&transport->connect_worker,
-					xs_udp_setup_socket);
 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP6);
 		break;
 	default:
@@ -2775,21 +2951,20 @@ static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
 	xprt->ops = &xs_tcp_ops;
 	xprt->timeout = &xs_tcp_default_timeout;
 
+	INIT_WORK(&transport->recv_worker, xs_tcp_data_receive_workfn);
+	INIT_DELAYED_WORK(&transport->connect_worker, xs_tcp_setup_socket);
+
 	switch (addr->sa_family) {
 	case AF_INET:
 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
 			xprt_set_bound(xprt);
 
-		INIT_DELAYED_WORK(&transport->connect_worker,
-					xs_tcp_setup_socket);
 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
 		break;
 	case AF_INET6:
 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
 			xprt_set_bound(xprt);
 
-		INIT_DELAYED_WORK(&transport->connect_worker,
-					xs_tcp_setup_socket);
 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
 		break;
 	default:
@@ -2989,7 +3164,7 @@ static int param_set_portnr(const char *val, const struct kernel_param *kp)
 			RPC_MAX_RESVPORT);
 }
 
-static struct kernel_param_ops param_ops_portnr = {
+static const struct kernel_param_ops param_ops_portnr = {
 	.set = param_set_portnr,
 	.get = param_get_uint,
 };
@@ -3008,7 +3183,7 @@ static int param_set_slot_table_size(const char *val,
 			RPC_MAX_SLOT_TABLE);
 }
 
-static struct kernel_param_ops param_ops_slot_table_size = {
+static const struct kernel_param_ops param_ops_slot_table_size = {
 	.set = param_set_slot_table_size,
 	.get = param_get_uint,
 };
@@ -3024,7 +3199,7 @@ static int param_set_max_slot_table_size(const char *val,
 			RPC_MAX_SLOT_TABLE_LIMIT);
 }
 
-static struct kernel_param_ops param_ops_max_slot_table_size = {
+static const struct kernel_param_ops param_ops_max_slot_table_size = {
 	.set = param_set_max_slot_table_size,
 	.get = param_get_uint,
 };