Merge tag 'nfs-for-4.2-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

Pull NFS client updates from Trond Myklebust:
 "Highlights include:

  Stable patches:
   - Fix a crash in the NFSv4 file locking code.
   - Fix an fsync() regression, where we were failing to retry I/O in
     some circumstances.
   - Fix an infinite loop in NFSv4.0 OPEN stateid recovery
   - Fix a memory leak when an attempted pnfs fails.
   - Fix a memory leak in the backchannel code
   - Large hostnames were not supported correctly in NFSv4.1
   - Fix a pNFS/flexfiles bug that was impeding error reporting on I/O.
   - Fix a couple of credential issues in pNFS/flexfiles

  Bugfixes + cleanups:
   - Open flag sanity checks in the NFSv4 atomic open codepath
   - More NFSv4 delegation related bugfixes
   - Various NFSv4.1 backchannel bugfixes and cleanups
   - Fix the NFS swap socket code
   - Various cleanups of the NFSv4 SETCLIENTID and EXCHANGE_ID code
   - Fix a UDP transport deadlock issue

  Features:
   - More RDMA client transport improvements
   - NFSv4.2 LAYOUTSTATS functionality for pnfs flexfiles"

* tag 'nfs-for-4.2-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (87 commits)
  nfs: Remove invalid tk_pid from debug message
  nfs: Remove invalid NFS_ATTR_FATTR_V4_REFERRAL checking in nfs4_get_rootfh
  nfs: Drop bad comment in nfs41_walk_client_list()
  nfs: Remove unneeded micro checking of CONFIG_PROC_FS
  nfs: Don't setting FILE_CREATED flags always
  nfs: Use remove_proc_subtree() instead remove_proc_entry()
  nfs: Remove unused argument in nfs_server_set_fsinfo()
  nfs: Fix a memory leak when meeting an unsupported state protect
  nfs: take extra reference to fl->fl_file when running a LOCKU operation
  NFSv4: When returning a delegation, don't reclaim an incompatible open mode.
  NFSv4.2: LAYOUTSTATS is optional to implement
  NFSv4.2: Fix up a decoding error in layoutstats
  pNFS/flexfiles: Fix the reset of struct pgio_header when resending
  pNFS/flexfiles: Turn off layoutcommit for servers that don't need it
  pnfs/flexfiles: protect ktime manipulation with mirror lock
  nfs: provide pnfs_report_layoutstat when NFS42 is disabled
  nfs: verify open flags before allowing open
  nfs: always update creds in mirror, even when we have an already connected ds
  nfs: fix potential credential leak in ff_layout_update_mirror_cred
  pnfs/flexfiles: report layoutstat regularly
  ...

15 files changed, 751 insertions, 532 deletions

diff --git a/net/sunrpc/Makefile b/net/sunrpc/Makefile
index 936ad0a..b512fbd 100644
--- a/net/sunrpc/Makefile
+++ b/net/sunrpc/Makefile
@@ -14,6 +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/net/sunrpc/backchannel_rqst.c b/net/sunrpc/backchannel_rqst.c
index 9dd0ea8d..9825ff0 100644
--- a/net/sunrpc/backchannel_rqst.c
+++ b/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;
 }
 
@@ -60,13 +62,62 @@ static void xprt_free_allocation(struct rpc_rqst *req)
 
 	dprintk("RPC:        free allocations for req= %p\n", req);
 	WARN_ON_ONCE(test_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state));
-	xbufp = &req->rq_private_buf;
+	xbufp = &req->rq_rcv_buf;
 	free_page((unsigned long)xbufp->head[0].iov_base);
 	xbufp = &req->rq_snd_buf;
 	free_page((unsigned long)xbufp->head[0].iov_base);
 	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 +138,7 @@ 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;
+	struct rpc_rqst *req;
 	struct list_head tmp_list;
 	int i;
 
@@ -106,7 +155,7 @@ 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 +164,6 @@ 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 +181,10 @@ 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);
 	}
@@ -217,9 +234,15 @@ 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;
+		/* Note: this 'free' request adds it to xprt->bc_pa_list */
+		xprt_free_bc_request(req);
+	}
 	req = list_first_entry(&xprt->bc_pa_list, struct rpc_rqst,
 				rq_bc_pa_list);
 	req->rq_reply_bytes_recvd = 0;
@@ -245,11 +268,21 @@ void xprt_free_bc_request(struct rpc_rqst *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 +293,6 @@ 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 +336,7 @@ 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->bc_alloc_count--;
 	spin_unlock(&xprt->bc_pa_lock);
 
 	req->rq_private_buf.len = copied;
diff --git a/net/sunrpc/bc_svc.c b/net/sunrpc/bc_svc.c
deleted file mode 100644
index 15c7a8a..0000000
--- a/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/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index e6ce151..cbc6af9 100644
--- a/net/sunrpc/clnt.c
+++ b/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);
 
@@ -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 */
 
@@ -2476,3 +2479,59 @@ 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/net/sunrpc/debugfs.c b/net/sunrpc/debugfs.c
index 82962f7..e7b4d93 100644
--- a/net/sunrpc/debugfs.c
+++ b/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/net/sunrpc/svc.c b/net/sunrpc/svc.c
index 852ae60..5a16d8d 100644
--- a/net/sunrpc/svc.c
+++ b/net/sunrpc/svc.c
@@ -1350,6 +1350,11 @@ 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;
@@ -1372,21 +1377,36 @@ bc_svc_process(struct svc_serv *serv, struct rpc_rqst *req,
 
 	/*
 	 * 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/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
index 1d4fe24..ab5dd62 100644
--- a/net/sunrpc/xprt.c
+++ b/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);
 }
 
@@ -967,6 +970,7 @@ 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;
@@ -1285,6 +1289,7 @@ 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/net/sunrpc/xprtrdma/fmr_ops.c b/net/sunrpc/xprtrdma/fmr_ops.c
index 302d4eb..f1e8daf 100644
--- a/net/sunrpc/xprtrdma/fmr_ops.c
+++ b/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/net/sunrpc/xprtrdma/frwr_ops.c b/net/sunrpc/xprtrdma/frwr_ops.c
index d234521..04ea914 100644
--- a/net/sunrpc/xprtrdma/frwr_ops.c
+++ b/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_fast_reg_mr(pd, 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)
@@ -128,7 +252,7 @@ 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 %s (%d)\n",
+	pr_warn("RPC:       %s: frmr %p flushed, status %s (%d)\n",
 		__func__, r, ib_wc_status_msg(wc->status), wc->status);
 	r->r.frmr.fr_state = FRMR_IS_STALE;
 }
@@ -137,16 +261,19 @@ 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 +292,7 @@ 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;
@@ -178,12 +306,12 @@ 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 rpcrdma_mw *mw;
+	struct rpcrdma_frmr *frmr;
+	struct ib_mr *mr;
 	struct ib_send_wr fastreg_wr, *bad_wr;
 	u8 key;
 	int len, pageoff;
@@ -192,12 +320,25 @@ frwr_op_map(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg,
 	u64 pa;
 	int page_no;
 
+	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;
+
 	pageoff = offset_in_page(seg1->mr_offset);
 	seg1->mr_offset -= pageoff;	/* start of page */
 	seg1->mr_len += pageoff;
 	len = -pageoff;
 	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;
@@ -216,8 +357,6 @@ frwr_op_map(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg,
 	dprintk("RPC:       %s: Using frmr %p to map %d segments (%d bytes)\n",
 		__func__, mw, i, len);
 
-	frmr->fr_state = FRMR_IS_VALID;
-
 	memset(&fastreg_wr, 0, sizeof(fastreg_wr));
 	fastreg_wr.wr_id = (unsigned long)(void *)mw;
 	fastreg_wr.opcode = IB_WR_FAST_REG_MR;
@@ -229,6 +368,7 @@ frwr_op_map(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg,
 	fastreg_wr.wr.fast_reg.access_flags = writing ?
 				IB_ACCESS_REMOTE_WRITE | IB_ACCESS_LOCAL_WRITE :
 				IB_ACCESS_REMOTE_READ;
+	mr = frmr->fr_mr;
 	key = (u8)(mr->rkey & 0x000000FF);
 	ib_update_fast_reg_key(mr, ++key);
 	fastreg_wr.wr.fast_reg.rkey = mr->rkey;
@@ -238,6 +378,7 @@ frwr_op_map(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg,
 	if (rc)
 		goto out_senderr;
 
+	seg1->rl_mw = mw;
 	seg1->mr_rkey = mr->rkey;
 	seg1->mr_base = seg1->mr_dma + pageoff;
 	seg1->mr_nsegs = i;
@@ -246,10 +387,9 @@ frwr_op_map(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg,
 
 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);
+	__frwr_queue_recovery(mw);
 	return rc;
 }
 
@@ -261,78 +401,46 @@ 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 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;
+	mw->r.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 = mw->r.frmr.fr_mr->rkey;
 	DECR_CQCOUNT(&r_xprt->rx_ep);
 
-	read_lock(&ia->ri_qplock);
-	device = ia->ri_id->device;
 	while (seg1->mr_nsegs--)
-		rpcrdma_unmap_one(device, seg++);
+		rpcrdma_unmap_one(ia->ri_device, seg++);
+	read_lock(&ia->ri_qplock);
 	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 +455,6 @@ 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/net/sunrpc/xprtrdma/physical_ops.c b/net/sunrpc/xprtrdma/physical_ops.c
index ba518af..41985d0 100644
--- a/net/sunrpc/xprtrdma/physical_ops.c
+++ b/net/sunrpc/xprtrdma/physical_ops.c
@@ -50,8 +50,7 @@ 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));
+	rpcrdma_map_one(ia->ri_device, seg, rpcrdma_data_dir(writing));
 	seg->mr_rkey = ia->ri_bind_mem->rkey;
 	seg->mr_base = seg->mr_dma;
 	seg->mr_nsegs = 1;
@@ -65,19 +64,11 @@ 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 +79,6 @@ 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/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c
index 2c53ea9..84ea37d 100644
--- a/net/sunrpc/xprtrdma/rpc_rdma.c
+++ b/net/sunrpc/xprtrdma/rpc_rdma.c
@@ -284,9 +284,6 @@ 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]);
@@ -732,8 +729,8 @@ 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;
@@ -770,7 +767,6 @@ rpcrdma_reply_handler(struct rpcrdma_rep *rep)
 			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);
 
diff --git a/net/sunrpc/xprtrdma/transport.c b/net/sunrpc/xprtrdma/transport.c
index 436da2c..680f888 100644
--- a/net/sunrpc/xprtrdma/transport.c
+++ b/net/sunrpc/xprtrdma/transport.c
@@ -240,6 +240,16 @@ 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
  *
@@ -612,12 +622,6 @@ 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;
@@ -676,6 +680,17 @@ static void xprt_rdma_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
 	   r_xprt->rx_stats.bad_reply_count);
 }
 
+static int
+xprt_rdma_enable_swap(struct rpc_xprt *xprt)
+{
+	return -EINVAL;
+}
+
+static void
+xprt_rdma_disable_swap(struct rpc_xprt *xprt)
+{
+}
+
 /*
  * Plumbing for rpc transport switch and kernel module
  */
@@ -694,7 +709,10 @@ 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
 };
 
 static struct xprt_class xprt_rdma = {
@@ -720,17 +738,24 @@ void xprt_rdma_cleanup(void)
 	if (rc)
 		dprintk("RPC:       %s: xprt_unregister returned %i\n",
 			__func__, rc);
+
+	frwr_destroy_recovery_wq();
 }
 
 int xprt_rdma_init(void)
 {
 	int rc;
 
-	rc = xprt_register_transport(&xprt_rdma);
-
+	rc = frwr_alloc_recovery_wq();
 	if (rc)
 		return rc;
 
+	rc = xprt_register_transport(&xprt_rdma);
+	if (rc) {
+		frwr_destroy_recovery_wq();
+		return rc;
+	}
+
 	dprintk("RPCRDMA Module Init, register RPC RDMA transport\n");
 
 	dprintk("Defaults:\n");
diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index 52df265..891c4ed 100644
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -80,7 +80,6 @@ static void
 rpcrdma_run_tasklet(unsigned long data)
 {
 	struct rpcrdma_rep *rep;
-	void (*func)(struct rpcrdma_rep *);
 	unsigned long flags;
 
 	data = data;
@@ -89,14 +88,9 @@ rpcrdma_run_tasklet(unsigned long data)
 		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);
+		rpcrdma_reply_handler(rep);
 
 		spin_lock_irqsave(&rpcrdma_tk_lock_g, flags);
 	}
@@ -236,7 +230,7 @@ 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));
@@ -407,7 +401,7 @@ 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!)" : "");
@@ -508,8 +502,9 @@ rpcrdma_ia_open(struct rpcrdma_xprt *xprt, struct sockaddr *addr, int memreg)
 		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",
@@ -517,7 +512,7 @@ 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);
@@ -526,7 +521,7 @@ rpcrdma_ia_open(struct rpcrdma_xprt *xprt, struct sockaddr *addr, int memreg)
 
 	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;
+		ia->ri_dma_lkey = ia->ri_device->local_dma_lkey;
 	}
 
 	if (memreg == RPCRDMA_FRMR) {
@@ -541,7 +536,7 @@ rpcrdma_ia_open(struct rpcrdma_xprt *xprt, struct sockaddr *addr, int memreg)
 		}
 	}
 	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;
@@ -590,9 +585,6 @@ 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;
 
@@ -622,17 +614,17 @@ rpcrdma_ia_close(struct rpcrdma_ia *ia)
 		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);
 		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))
+		WARN_ON(ib_dealloc_pd(ia->ri_pd));
 }
 
 /*
@@ -693,8 +685,8 @@ rpcrdma_ep_create(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia,
 	INIT_DELAYED_WORK(&ep->rep_connect_worker, rpcrdma_connect_worker);
 
 	cq_attr.cqe = ep->rep_attr.cap.max_send_wr + 1;
-	sendcq = ib_create_cq(ia->ri_id->device, rpcrdma_sendcq_upcall,
-				  rpcrdma_cq_async_error_upcall, ep, &cq_attr);
+	sendcq = ib_create_cq(ia->ri_device, rpcrdma_sendcq_upcall,
+			      rpcrdma_cq_async_error_upcall, ep, &cq_attr);
 	if (IS_ERR(sendcq)) {
 		rc = PTR_ERR(sendcq);
 		dprintk("RPC:       %s: failed to create send CQ: %i\n",
@@ -710,8 +702,8 @@ rpcrdma_ep_create(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia,
 	}
 
 	cq_attr.cqe = ep->rep_attr.cap.max_recv_wr + 1;
-	recvcq = ib_create_cq(ia->ri_id->device, rpcrdma_recvcq_upcall,
-				  rpcrdma_cq_async_error_upcall, ep, &cq_attr);
+	recvcq = ib_create_cq(ia->ri_device, rpcrdma_recvcq_upcall,
+			      rpcrdma_cq_async_error_upcall, ep, &cq_attr);
 	if (IS_ERR(recvcq)) {
 		rc = PTR_ERR(recvcq);
 		dprintk("RPC:       %s: failed to create recv CQ: %i\n",
@@ -817,8 +809,6 @@ 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)) {
@@ -832,7 +822,7 @@ 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);
@@ -974,7 +964,8 @@ 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;
 	return rep;
 
 out_free:
@@ -1098,31 +1089,33 @@ rpcrdma_buffer_destroy(struct rpcrdma_buffer *buf)
 	kfree(buf->rb_pool);
 }
 
-/* "*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)
+struct rpcrdma_mw *
+rpcrdma_get_mw(struct rpcrdma_xprt *r_xprt)
 {
-	if (*mw) {
-		list_add_tail(&(*mw)->mw_list, &buf->rb_mws);
-		*mw = NULL;
+	struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
+	struct rpcrdma_mw *mw = NULL;
+
+	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);
+
+	if (!mw)
+		pr_err("RPC:       %s: no MWs available\n", __func__);
+	return mw;
 }
 
-/* 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)
+void
+rpcrdma_put_mw(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mw *mw)
 {
-	struct rpcrdma_mr_seg *seg = req->rl_segments;
-	struct rpcrdma_mr_seg *seg1 = seg;
-	int i;
+	struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
 
-	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);
+	spin_lock(&buf->rb_mwlock);
+	list_add_tail(&mw->mw_list, &buf->rb_mws);
+	spin_unlock(&buf->rb_mwlock);
 }
 
 static void
@@ -1132,115 +1125,10 @@ rpcrdma_buffer_put_sendbuf(struct rpcrdma_req *req, struct rpcrdma_buffer *buf)
 	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;
 	}
 }
 
-/* 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);
-
-	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);
-	}
-}
-
-static void
-rpcrdma_retry_flushed_linv(struct list_head *stale,
-			   struct rpcrdma_buffer *buf)
-{
-	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);
-}
-
-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 */
-	}
-
-	/* Not enough entries on rb_mws for this req */
-	rpcrdma_buffer_put_sendbuf(req, buf);
-	rpcrdma_buffer_put_mrs(req, buf);
-	return NULL;
-}
-
-static struct rpcrdma_req *
-rpcrdma_buffer_get_fmrs(struct rpcrdma_req *req, struct rpcrdma_buffer *buf)
-{
-	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 */
-	}
-
-	/* Not enough entries on rb_mws for this req */
-	rpcrdma_buffer_put_sendbuf(req, buf);
-	rpcrdma_buffer_put_mrs(req, buf);
-	return NULL;
-}
-
 /*
  * Get a set of request/reply buffers.
  *
@@ -1253,12 +1141,11 @@ rpcrdma_buffer_get_fmrs(struct rpcrdma_req *req, struct rpcrdma_buffer *buf)
 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__);
@@ -1277,20 +1164,7 @@ rpcrdma_buffer_get(struct rpcrdma_buffer *buffers)
 	}
 	buffers->rb_send_bufs[buffers->rb_send_index++] = NULL;
 
-	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);
 	return req;
 }
 
@@ -1302,19 +1176,10 @@ 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;
 
 	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);
 }
 
@@ -1344,10 +1209,9 @@ rpcrdma_recv_buffer_get(struct rpcrdma_req *req)
 void
 rpcrdma_recv_buffer_put(struct rpcrdma_rep *rep)
 {
-	struct rpcrdma_buffer *buffers = rep->rr_buffer;
+	struct rpcrdma_buffer *buffers = &rep->rr_rxprt->rx_buf;
 	unsigned long flags;
 
-	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);
@@ -1376,9 +1240,9 @@ rpcrdma_register_internal(struct rpcrdma_ia *ia, void *va, int len,
 	/*
 	 * All memory passed here was kmalloc'ed, therefore phys-contiguous.
 	 */
-	iov->addr = ib_dma_map_single(ia->ri_id->device,
+	iov->addr = ib_dma_map_single(ia->ri_device,
 			va, len, DMA_BIDIRECTIONAL);
-	if (ib_dma_mapping_error(ia->ri_id->device, iov->addr))
+	if (ib_dma_mapping_error(ia->ri_device, iov->addr))
 		return -ENOMEM;
 
 	iov->length = len;
@@ -1422,8 +1286,8 @@ rpcrdma_deregister_internal(struct rpcrdma_ia *ia,
 {
 	int rc;
 
-	ib_dma_unmap_single(ia->ri_id->device,
-			iov->addr, iov->length, DMA_BIDIRECTIONAL);
+	ib_dma_unmap_single(ia->ri_device,
+			    iov->addr, iov->length, DMA_BIDIRECTIONAL);
 
 	if (NULL == mr)
 		return 0;
@@ -1516,15 +1380,18 @@ rpcrdma_ep_post(struct rpcrdma_ia *ia,
 	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);
+		ib_dma_sync_single_for_device(ia->ri_device,
+					      req->rl_send_iov[3].addr,
+					      req->rl_send_iov[3].length,
+					      DMA_TO_DEVICE);
+	ib_dma_sync_single_for_device(ia->ri_device,
+				      req->rl_send_iov[1].addr,
+				      req->rl_send_iov[1].length,
+				      DMA_TO_DEVICE);
+	ib_dma_sync_single_for_device(ia->ri_device,
+				      req->rl_send_iov[0].addr,
+				      req->rl_send_iov[0].length,
+				      DMA_TO_DEVICE);
 
 	if (DECR_CQCOUNT(ep) > 0)
 		send_wr.send_flags = 0;
@@ -1557,7 +1424,7 @@ 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);
diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h
index 58163b8..f49dd8b 100644
--- a/net/sunrpc/xprtrdma/xprt_rdma.h
+++ b/net/sunrpc/xprtrdma/xprt_rdma.h
@@ -62,6 +62,7 @@
 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;
@@ -69,7 +70,6 @@ struct rpcrdma_ia {
 	int			ri_have_dma_lkey;
 	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;
@@ -173,9 +173,8 @@ 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 list_head	rr_list;
 	struct rpcrdma_regbuf	*rr_rdmabuf;
 };
@@ -203,11 +202,18 @@ struct rpcrdma_frmr {
 	struct ib_fast_reg_page_list	*fr_pgl;
 	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 *);
@@ -281,15 +287,17 @@ 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;
+	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 arrays */
+	u32			rb_max_requests;
+	int			rb_send_index;
+	int			rb_recv_index;
 	struct rpcrdma_req	**rb_send_bufs;
-	int		rb_recv_index;
 	struct rpcrdma_rep	**rb_recv_bufs;
-	char		*rb_pool;
 };
 #define rdmab_to_ia(b) (&container_of((b), struct rpcrdma_xprt, rx_buf)->rx_ia)
 
@@ -350,7 +358,6 @@ 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;
 };
@@ -413,6 +420,8 @@ int rpcrdma_ep_post_recv(struct rpcrdma_ia *, struct rpcrdma_ep *,
 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 *);
@@ -425,6 +434,9 @@ void rpcrdma_free_regbuf(struct rpcrdma_ia *,
 
 unsigned int rpcrdma_max_segments(struct rpcrdma_xprt *);
 
+int frwr_alloc_recovery_wq(void);
+void frwr_destroy_recovery_wq(void);
+
 /*
  * Wrappers for chunk registration, shared by read/write chunk code.
  */
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index b051728..e193c2b 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -623,24 +623,6 @@ process_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
  *
@@ -786,6 +768,7 @@ static void xs_sock_mark_closed(struct rpc_xprt *xprt)
 	xs_sock_reset_connection_flags(xprt);
 	/* Mark transport as closed and wake up all pending tasks */
 	xprt_disconnect_done(xprt);
+	xprt_force_disconnect(xprt);
 }
 
 /**
@@ -827,6 +810,9 @@ static void xs_reset_transport(struct sock_xprt *transport)
 	if (sk == NULL)
 		return;
 
+	if (atomic_read(&transport->xprt.swapper))
+		sk_clear_memalloc(sk);
+
 	write_lock_bh(&sk->sk_callback_lock);
 	transport->inet = NULL;
 	transport->sock = NULL;
@@ -863,6 +849,13 @@ 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);
@@ -901,7 +894,6 @@ 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
  *
  * Currently this assumes we can read the whole reply in a single gulp.
  */
@@ -965,7 +957,6 @@ static void xs_local_data_ready(struct sock *sk)
 /**
  * xs_udp_data_ready - "data ready" callback for UDP sockets
  * @sk: socket with data to read
- * @len: how much data to read
  *
  */
 static void xs_udp_data_ready(struct sock *sk)
@@ -1389,7 +1380,6 @@ static int xs_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, uns
 /**
  * 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)
@@ -1886,9 +1876,7 @@ 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)
 {
@@ -1960,43 +1948,84 @@ 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)
@@ -2057,6 +2086,27 @@ 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);
@@ -2067,6 +2117,7 @@ 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,
@@ -2078,6 +2129,12 @@ 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);
@@ -2125,9 +2182,6 @@ 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.
  */
@@ -2463,6 +2517,8 @@ 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 = {
@@ -2482,6 +2538,9 @@ 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 = {
@@ -2498,6 +2557,9 @@ 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,
 };
 
 /*
@@ -2515,6 +2577,9 @@ 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)