Merge tag 'nfs-for-3.17-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

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

   - stable fix for a bug in nfs3_list_one_acl()
   - speed up NFS path walks by supporting LOOKUP_RCU
   - more read/write code cleanups
   - pNFS fixes for layout return on close
   - fixes for the RCU handling in the rpcsec_gss code
   - more NFS/RDMA fixes"

* tag 'nfs-for-3.17-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (79 commits)
  nfs: reject changes to resvport and sharecache during remount
  NFS: Avoid infinite loop when RELEASE_LOCKOWNER getting expired error
  SUNRPC: remove all refcounting of groupinfo from rpcauth_lookupcred
  NFS: fix two problems in lookup_revalidate in RCU-walk
  NFS: allow lockless access to access_cache
  NFS: teach nfs_lookup_verify_inode to handle LOOKUP_RCU
  NFS: teach nfs_neg_need_reval to understand LOOKUP_RCU
  NFS: support RCU_WALK in nfs_permission()
  sunrpc/auth: allow lockless (rcu) lookup of credential cache.
  NFS: prepare for RCU-walk support but pushing tests later in code.
  NFS: nfs4_lookup_revalidate: only evaluate parent if it will be used.
  NFS: add checks for returned value of try_module_get()
  nfs: clear_request_commit while holding i_lock
  pnfs: add pnfs_put_lseg_async
  pnfs: find swapped pages on pnfs commit lists too
  nfs: fix comment and add warn_on for PG_INODE_REF
  nfs: check wait_on_bit_lock err in page_group_lock
  sunrpc: remove "ec" argument from encrypt_v2 operation
  sunrpc: clean up sparse endianness warnings in gss_krb5_wrap.c
  sunrpc: clean up sparse endianness warnings in gss_krb5_seal.c
  ...

16 files changed, 809 insertions, 383 deletions

diff --git a/net/sunrpc/addr.c b/net/sunrpc/addr.c
index a622ad6..2e0a6f9 100644
--- a/net/sunrpc/addr.c
+++ b/net/sunrpc/addr.c
@@ -176,7 +176,7 @@ static int rpc_parse_scope_id(struct net *net, const char *buf,
 	len = (buf + buflen) - delim - 1;
 	p = kstrndup(delim + 1, len, GFP_KERNEL);
 	if (p) {
-		unsigned long scope_id = 0;
+		u32 scope_id = 0;
 		struct net_device *dev;
 
 		dev = dev_get_by_name(net, p);
@@ -184,7 +184,7 @@ static int rpc_parse_scope_id(struct net *net, const char *buf,
 			scope_id = dev->ifindex;
 			dev_put(dev);
 		} else {
-			if (strict_strtoul(p, 10, &scope_id) == 0) {
+			if (kstrtou32(p, 10, &scope_id) == 0) {
 				kfree(p);
 				return 0;
 			}
@@ -304,7 +304,7 @@ char *rpc_sockaddr2uaddr(const struct sockaddr *sap, gfp_t gfp_flags)
  * @sap: buffer into which to plant socket address
  * @salen: size of buffer
  *
- * @uaddr does not have to be '\0'-terminated, but strict_strtoul() and
+ * @uaddr does not have to be '\0'-terminated, but kstrtou8() and
  * rpc_pton() require proper string termination to be successful.
  *
  * Returns the size of the socket address if successful; otherwise
@@ -315,7 +315,7 @@ size_t rpc_uaddr2sockaddr(struct net *net, const char *uaddr,
 			  const size_t salen)
 {
 	char *c, buf[RPCBIND_MAXUADDRLEN + sizeof('\0')];
-	unsigned long portlo, porthi;
+	u8 portlo, porthi;
 	unsigned short port;
 
 	if (uaddr_len > RPCBIND_MAXUADDRLEN)
@@ -327,18 +327,14 @@ size_t rpc_uaddr2sockaddr(struct net *net, const char *uaddr,
 	c = strrchr(buf, '.');
 	if (unlikely(c == NULL))
 		return 0;
-	if (unlikely(strict_strtoul(c + 1, 10, &portlo) != 0))
-		return 0;
-	if (unlikely(portlo > 255))
+	if (unlikely(kstrtou8(c + 1, 10, &portlo) != 0))
 		return 0;
 
 	*c = '\0';
 	c = strrchr(buf, '.');
 	if (unlikely(c == NULL))
 		return 0;
-	if (unlikely(strict_strtoul(c + 1, 10, &porthi) != 0))
-		return 0;
-	if (unlikely(porthi > 255))
+	if (unlikely(kstrtou8(c + 1, 10, &porthi) != 0))
 		return 0;
 
 	port = (unsigned short)((porthi << 8) | portlo);
diff --git a/net/sunrpc/auth.c b/net/sunrpc/auth.c
index f773667..383eb91 100644
--- a/net/sunrpc/auth.c
+++ b/net/sunrpc/auth.c
@@ -48,7 +48,7 @@ static int param_set_hashtbl_sz(const char *val, const struct kernel_param *kp)
 
 	if (!val)
 		goto out_inval;
-	ret = strict_strtoul(val, 0, &num);
+	ret = kstrtoul(val, 0, &num);
 	if (ret == -EINVAL)
 		goto out_inval;
 	nbits = fls(num);
@@ -80,6 +80,10 @@ static struct kernel_param_ops param_ops_hashtbl_sz = {
 module_param_named(auth_hashtable_size, auth_hashbits, hashtbl_sz, 0644);
 MODULE_PARM_DESC(auth_hashtable_size, "RPC credential cache hashtable size");
 
+static unsigned long auth_max_cred_cachesize = ULONG_MAX;
+module_param(auth_max_cred_cachesize, ulong, 0644);
+MODULE_PARM_DESC(auth_max_cred_cachesize, "RPC credential maximum total cache size");
+
 static u32
 pseudoflavor_to_flavor(u32 flavor) {
 	if (flavor > RPC_AUTH_MAXFLAVOR)
@@ -363,6 +367,15 @@ rpcauth_cred_key_to_expire(struct rpc_cred *cred)
 }
 EXPORT_SYMBOL_GPL(rpcauth_cred_key_to_expire);
 
+char *
+rpcauth_stringify_acceptor(struct rpc_cred *cred)
+{
+	if (!cred->cr_ops->crstringify_acceptor)
+		return NULL;
+	return cred->cr_ops->crstringify_acceptor(cred);
+}
+EXPORT_SYMBOL_GPL(rpcauth_stringify_acceptor);
+
 /*
  * Destroy a list of credentials
  */
@@ -472,6 +485,20 @@ rpcauth_prune_expired(struct list_head *free, int nr_to_scan)
 	return freed;
 }
 
+static unsigned long
+rpcauth_cache_do_shrink(int nr_to_scan)
+{
+	LIST_HEAD(free);
+	unsigned long freed;
+
+	spin_lock(&rpc_credcache_lock);
+	freed = rpcauth_prune_expired(&free, nr_to_scan);
+	spin_unlock(&rpc_credcache_lock);
+	rpcauth_destroy_credlist(&free);
+
+	return freed;
+}
+
 /*
  * Run memory cache shrinker.
  */
@@ -479,9 +506,6 @@ static unsigned long
 rpcauth_cache_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
 
 {
-	LIST_HEAD(free);
-	unsigned long freed;
-
 	if ((sc->gfp_mask & GFP_KERNEL) != GFP_KERNEL)
 		return SHRINK_STOP;
 
@@ -489,12 +513,7 @@ rpcauth_cache_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
 	if (list_empty(&cred_unused))
 		return SHRINK_STOP;
 
-	spin_lock(&rpc_credcache_lock);
-	freed = rpcauth_prune_expired(&free, sc->nr_to_scan);
-	spin_unlock(&rpc_credcache_lock);
-	rpcauth_destroy_credlist(&free);
-
-	return freed;
+	return rpcauth_cache_do_shrink(sc->nr_to_scan);
 }
 
 static unsigned long
@@ -504,6 +523,21 @@ rpcauth_cache_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
 	return (number_cred_unused / 100) * sysctl_vfs_cache_pressure;
 }
 
+static void
+rpcauth_cache_enforce_limit(void)
+{
+	unsigned long diff;
+	unsigned int nr_to_scan;
+
+	if (number_cred_unused <= auth_max_cred_cachesize)
+		return;
+	diff = number_cred_unused - auth_max_cred_cachesize;
+	nr_to_scan = 100;
+	if (diff < nr_to_scan)
+		nr_to_scan = diff;
+	rpcauth_cache_do_shrink(nr_to_scan);
+}
+
 /*
  * Look up a process' credentials in the authentication cache
  */
@@ -523,6 +557,12 @@ rpcauth_lookup_credcache(struct rpc_auth *auth, struct auth_cred * acred,
 	hlist_for_each_entry_rcu(entry, &cache->hashtable[nr], cr_hash) {
 		if (!entry->cr_ops->crmatch(acred, entry, flags))
 			continue;
+		if (flags & RPCAUTH_LOOKUP_RCU) {
+			if (test_bit(RPCAUTH_CRED_HASHED, &entry->cr_flags) &&
+			    !test_bit(RPCAUTH_CRED_NEW, &entry->cr_flags))
+				cred = entry;
+			break;
+		}
 		spin_lock(&cache->lock);
 		if (test_bit(RPCAUTH_CRED_HASHED, &entry->cr_flags) == 0) {
 			spin_unlock(&cache->lock);
@@ -537,6 +577,9 @@ rpcauth_lookup_credcache(struct rpc_auth *auth, struct auth_cred * acred,
 	if (cred != NULL)
 		goto found;
 
+	if (flags & RPCAUTH_LOOKUP_RCU)
+		return ERR_PTR(-ECHILD);
+
 	new = auth->au_ops->crcreate(auth, acred, flags);
 	if (IS_ERR(new)) {
 		cred = new;
@@ -557,6 +600,7 @@ rpcauth_lookup_credcache(struct rpc_auth *auth, struct auth_cred * acred,
 	} else
 		list_add_tail(&new->cr_lru, &free);
 	spin_unlock(&cache->lock);
+	rpcauth_cache_enforce_limit();
 found:
 	if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
 	    cred->cr_ops->cr_init != NULL &&
@@ -586,10 +630,8 @@ rpcauth_lookupcred(struct rpc_auth *auth, int flags)
 	memset(&acred, 0, sizeof(acred));
 	acred.uid = cred->fsuid;
 	acred.gid = cred->fsgid;
-	acred.group_info = get_group_info(((struct cred *)cred)->group_info);
-
+	acred.group_info = cred->group_info;
 	ret = auth->au_ops->lookup_cred(auth, &acred, flags);
-	put_group_info(acred.group_info);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(rpcauth_lookupcred);
diff --git a/net/sunrpc/auth_generic.c b/net/sunrpc/auth_generic.c
index ed04869..6f6b829 100644
--- a/net/sunrpc/auth_generic.c
+++ b/net/sunrpc/auth_generic.c
@@ -38,6 +38,12 @@ struct rpc_cred *rpc_lookup_cred(void)
 }
 EXPORT_SYMBOL_GPL(rpc_lookup_cred);
 
+struct rpc_cred *rpc_lookup_cred_nonblock(void)
+{
+	return rpcauth_lookupcred(&generic_auth, RPCAUTH_LOOKUP_RCU);
+}
+EXPORT_SYMBOL_GPL(rpc_lookup_cred_nonblock);
+
 /*
  * Public call interface for looking up machine creds.
  */
diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c
index b6e440b..afb292c 100644
--- a/net/sunrpc/auth_gss/auth_gss.c
+++ b/net/sunrpc/auth_gss/auth_gss.c
@@ -183,8 +183,9 @@ gss_cred_get_ctx(struct rpc_cred *cred)
 	struct gss_cl_ctx *ctx = NULL;
 
 	rcu_read_lock();
-	if (gss_cred->gc_ctx)
-		ctx = gss_get_ctx(gss_cred->gc_ctx);
+	ctx = rcu_dereference(gss_cred->gc_ctx);
+	if (ctx)
+		gss_get_ctx(ctx);
 	rcu_read_unlock();
 	return ctx;
 }
@@ -262,9 +263,22 @@ gss_fill_context(const void *p, const void *end, struct gss_cl_ctx *ctx, struct
 		p = ERR_PTR(ret);
 		goto err;
 	}
-	dprintk("RPC:       %s Success. gc_expiry %lu now %lu timeout %u\n",
-		__func__, ctx->gc_expiry, now, timeout);
-	return q;
+
+	/* is there any trailing data? */
+	if (q == end) {
+		p = q;
+		goto done;
+	}
+
+	/* pull in acceptor name (if there is one) */
+	p = simple_get_netobj(q, end, &ctx->gc_acceptor);
+	if (IS_ERR(p))
+		goto err;
+done:
+	dprintk("RPC:       %s Success. gc_expiry %lu now %lu timeout %u acceptor %.*s\n",
+		__func__, ctx->gc_expiry, now, timeout, ctx->gc_acceptor.len,
+		ctx->gc_acceptor.data);
+	return p;
 err:
 	dprintk("RPC:       %s returns error %ld\n", __func__, -PTR_ERR(p));
 	return p;
@@ -1194,13 +1208,13 @@ gss_destroying_context(struct rpc_cred *cred)
 {
 	struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 	struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
+	struct gss_cl_ctx *ctx = rcu_dereference_protected(gss_cred->gc_ctx, 1);
 	struct rpc_task *task;
 
-	if (gss_cred->gc_ctx == NULL ||
-	    test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
+	if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
 		return 0;
 
-	gss_cred->gc_ctx->gc_proc = RPC_GSS_PROC_DESTROY;
+	ctx->gc_proc = RPC_GSS_PROC_DESTROY;
 	cred->cr_ops = &gss_nullops;
 
 	/* Take a reference to ensure the cred will be destroyed either
@@ -1225,6 +1239,7 @@ gss_do_free_ctx(struct gss_cl_ctx *ctx)
 
 	gss_delete_sec_context(&ctx->gc_gss_ctx);
 	kfree(ctx->gc_wire_ctx.data);
+	kfree(ctx->gc_acceptor.data);
 	kfree(ctx);
 }
 
@@ -1260,7 +1275,7 @@ gss_destroy_nullcred(struct rpc_cred *cred)
 {
 	struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 	struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
-	struct gss_cl_ctx *ctx = gss_cred->gc_ctx;
+	struct gss_cl_ctx *ctx = rcu_dereference_protected(gss_cred->gc_ctx, 1);
 
 	RCU_INIT_POINTER(gss_cred->gc_ctx, NULL);
 	call_rcu(&cred->cr_rcu, gss_free_cred_callback);
@@ -1332,6 +1347,36 @@ gss_cred_init(struct rpc_auth *auth, struct rpc_cred *cred)
 	return err;
 }
 
+static char *
+gss_stringify_acceptor(struct rpc_cred *cred)
+{
+	char *string = NULL;
+	struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
+	struct gss_cl_ctx *ctx;
+	struct xdr_netobj *acceptor;
+
+	rcu_read_lock();
+	ctx = rcu_dereference(gss_cred->gc_ctx);
+	if (!ctx)
+		goto out;
+
+	acceptor = &ctx->gc_acceptor;
+
+	/* no point if there's no string */
+	if (!acceptor->len)
+		goto out;
+
+	string = kmalloc(acceptor->len + 1, GFP_KERNEL);
+	if (!string)
+		goto out;
+
+	memcpy(string, acceptor->data, acceptor->len);
+	string[acceptor->len] = '\0';
+out:
+	rcu_read_unlock();
+	return string;
+}
+
 /*
  * Returns -EACCES if GSS context is NULL or will expire within the
  * timeout (miliseconds)
@@ -1340,15 +1385,16 @@ static int
 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;
 
-	if (gss_cred->gc_ctx == NULL)
-		return -EACCES;
-
-	expire = gss_cred->gc_ctx->gc_expiry - (gss_key_expire_timeo * HZ);
-
-	if (time_after(now, expire))
+	rcu_read_lock();
+	ctx = rcu_dereference(gss_cred->gc_ctx);
+	if (ctx)
+		expire = ctx->gc_expiry - (gss_key_expire_timeo * HZ);
+	rcu_read_unlock();
+	if (!ctx || time_after(now, expire))
 		return -EACCES;
 	return 0;
 }
@@ -1357,13 +1403,19 @@ static int
 gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags)
 {
 	struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
+	struct gss_cl_ctx *ctx;
 	int ret;
 
 	if (test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags))
 		goto out;
 	/* Don't match with creds that have expired. */
-	if (time_after(jiffies, gss_cred->gc_ctx->gc_expiry))
+	rcu_read_lock();
+	ctx = rcu_dereference(gss_cred->gc_ctx);
+	if (!ctx || time_after(jiffies, ctx->gc_expiry)) {
+		rcu_read_unlock();
 		return 0;
+	}
+	rcu_read_unlock();
 	if (!test_bit(RPCAUTH_CRED_UPTODATE, &rc->cr_flags))
 		return 0;
 out:
@@ -1909,29 +1961,31 @@ static const struct rpc_authops authgss_ops = {
 };
 
 static const struct rpc_credops gss_credops = {
-	.cr_name	= "AUTH_GSS",
-	.crdestroy	= gss_destroy_cred,
-	.cr_init	= gss_cred_init,
-	.crbind		= rpcauth_generic_bind_cred,
-	.crmatch	= gss_match,
-	.crmarshal	= gss_marshal,
-	.crrefresh	= gss_refresh,
-	.crvalidate	= gss_validate,
-	.crwrap_req	= gss_wrap_req,
-	.crunwrap_resp	= gss_unwrap_resp,
-	.crkey_timeout	= gss_key_timeout,
+	.cr_name		= "AUTH_GSS",
+	.crdestroy		= gss_destroy_cred,
+	.cr_init		= gss_cred_init,
+	.crbind			= rpcauth_generic_bind_cred,
+	.crmatch		= gss_match,
+	.crmarshal		= gss_marshal,
+	.crrefresh		= gss_refresh,
+	.crvalidate		= gss_validate,
+	.crwrap_req		= gss_wrap_req,
+	.crunwrap_resp		= gss_unwrap_resp,
+	.crkey_timeout		= gss_key_timeout,
+	.crstringify_acceptor	= gss_stringify_acceptor,
 };
 
 static const struct rpc_credops gss_nullops = {
-	.cr_name	= "AUTH_GSS",
-	.crdestroy	= gss_destroy_nullcred,
-	.crbind		= rpcauth_generic_bind_cred,
-	.crmatch	= gss_match,
-	.crmarshal	= gss_marshal,
-	.crrefresh	= gss_refresh_null,
-	.crvalidate	= gss_validate,
-	.crwrap_req	= gss_wrap_req,
-	.crunwrap_resp	= gss_unwrap_resp,
+	.cr_name		= "AUTH_GSS",
+	.crdestroy		= gss_destroy_nullcred,
+	.crbind			= rpcauth_generic_bind_cred,
+	.crmatch		= gss_match,
+	.crmarshal		= gss_marshal,
+	.crrefresh		= gss_refresh_null,
+	.crvalidate		= gss_validate,
+	.crwrap_req		= gss_wrap_req,
+	.crunwrap_resp		= gss_unwrap_resp,
+	.crstringify_acceptor	= gss_stringify_acceptor,
 };
 
 static const struct rpc_pipe_ops gss_upcall_ops_v0 = {
diff --git a/net/sunrpc/auth_gss/gss_krb5_crypto.c b/net/sunrpc/auth_gss/gss_krb5_crypto.c
index 0f43e89..f5ed9f6 100644
--- a/net/sunrpc/auth_gss/gss_krb5_crypto.c
+++ b/net/sunrpc/auth_gss/gss_krb5_crypto.c
@@ -641,7 +641,7 @@ out:
 
 u32
 gss_krb5_aes_encrypt(struct krb5_ctx *kctx, u32 offset,
-		     struct xdr_buf *buf, int ec, struct page **pages)
+		     struct xdr_buf *buf, struct page **pages)
 {
 	u32 err;
 	struct xdr_netobj hmac;
@@ -684,13 +684,8 @@ gss_krb5_aes_encrypt(struct krb5_ctx *kctx, u32 offset,
 		ecptr = buf->tail[0].iov_base;
 	}
 
-	memset(ecptr, 'X', ec);
-	buf->tail[0].iov_len += ec;
-	buf->len += ec;
-
 	/* copy plaintext gss token header after filler (if any) */
-	memcpy(ecptr + ec, buf->head[0].iov_base + offset,
-						GSS_KRB5_TOK_HDR_LEN);
+	memcpy(ecptr, buf->head[0].iov_base + offset, GSS_KRB5_TOK_HDR_LEN);
 	buf->tail[0].iov_len += GSS_KRB5_TOK_HDR_LEN;
 	buf->len += GSS_KRB5_TOK_HDR_LEN;
 
diff --git a/net/sunrpc/auth_gss/gss_krb5_seal.c b/net/sunrpc/auth_gss/gss_krb5_seal.c
index 62ae327..42768e5 100644
--- a/net/sunrpc/auth_gss/gss_krb5_seal.c
+++ b/net/sunrpc/auth_gss/gss_krb5_seal.c
@@ -70,31 +70,37 @@
 
 DEFINE_SPINLOCK(krb5_seq_lock);
 
-static char *
+static void *
 setup_token(struct krb5_ctx *ctx, struct xdr_netobj *token)
 {
-	__be16 *ptr, *krb5_hdr;
+	u16 *ptr;
+	void *krb5_hdr;
 	int body_size = GSS_KRB5_TOK_HDR_LEN + ctx->gk5e->cksumlength;
 
 	token->len = g_token_size(&ctx->mech_used, body_size);
 
-	ptr = (__be16 *)token->data;
+	ptr = (u16 *)token->data;
 	g_make_token_header(&ctx->mech_used, body_size, (unsigned char **)&ptr);
 
 	/* ptr now at start of header described in rfc 1964, section 1.2.1: */
 	krb5_hdr = ptr;
 	*ptr++ = KG_TOK_MIC_MSG;
-	*ptr++ = cpu_to_le16(ctx->gk5e->signalg);
+	/*
+	 * signalg is stored as if it were converted from LE to host endian, even
+	 * though it's an opaque pair of bytes according to the RFC.
+	 */
+	*ptr++ = (__force u16)cpu_to_le16(ctx->gk5e->signalg);
 	*ptr++ = SEAL_ALG_NONE;
-	*ptr++ = 0xffff;
+	*ptr = 0xffff;
 
-	return (char *)krb5_hdr;
+	return krb5_hdr;
 }
 
 static void *
 setup_token_v2(struct krb5_ctx *ctx, struct xdr_netobj *token)
 {
-	__be16 *ptr, *krb5_hdr;
+	u16 *ptr;
+	void *krb5_hdr;
 	u8 *p, flags = 0x00;
 
 	if ((ctx->flags & KRB5_CTX_FLAG_INITIATOR) == 0)
@@ -104,15 +110,15 @@ setup_token_v2(struct krb5_ctx *ctx, struct xdr_netobj *token)
 
 	/* Per rfc 4121, sec 4.2.6.1, there is no header,
 	 * just start the token */
-	krb5_hdr = ptr = (__be16 *)token->data;
+	krb5_hdr = ptr = (u16 *)token->data;
 
 	*ptr++ = KG2_TOK_MIC;
 	p = (u8 *)ptr;
 	*p++ = flags;
 	*p++ = 0xff;
-	ptr = (__be16 *)p;
-	*ptr++ = 0xffff;
+	ptr = (u16 *)p;
 	*ptr++ = 0xffff;
+	*ptr = 0xffff;
 
 	token->len = GSS_KRB5_TOK_HDR_LEN + ctx->gk5e->cksumlength;
 	return krb5_hdr;
@@ -181,7 +187,7 @@ gss_get_mic_v2(struct krb5_ctx *ctx, struct xdr_buf *text,
 	spin_lock(&krb5_seq_lock);
 	seq_send = ctx->seq_send64++;
 	spin_unlock(&krb5_seq_lock);
-	*((u64 *)(krb5_hdr + 8)) = cpu_to_be64(seq_send);
+	*((__be64 *)(krb5_hdr + 8)) = cpu_to_be64(seq_send);
 
 	if (ctx->initiate) {
 		cksumkey = ctx->initiator_sign;
diff --git a/net/sunrpc/auth_gss/gss_krb5_wrap.c b/net/sunrpc/auth_gss/gss_krb5_wrap.c
index 42560e5..4b614c6 100644
--- a/net/sunrpc/auth_gss/gss_krb5_wrap.c
+++ b/net/sunrpc/auth_gss/gss_krb5_wrap.c
@@ -201,9 +201,15 @@ gss_wrap_kerberos_v1(struct krb5_ctx *kctx, int offset,
 
 	msg_start = ptr + GSS_KRB5_TOK_HDR_LEN + kctx->gk5e->cksumlength;
 
-	*(__be16 *)(ptr + 2) = cpu_to_le16(kctx->gk5e->signalg);
-	memset(ptr + 4, 0xff, 4);
-	*(__be16 *)(ptr + 4) = cpu_to_le16(kctx->gk5e->sealalg);
+	/*
+	 * signalg and sealalg are stored as if they were converted from LE
+	 * to host endian, even though they're opaque pairs of bytes according
+	 * to the RFC.
+	 */
+	*(__le16 *)(ptr + 2) = cpu_to_le16(kctx->gk5e->signalg);
+	*(__le16 *)(ptr + 4) = cpu_to_le16(kctx->gk5e->sealalg);
+	ptr[6] = 0xff;
+	ptr[7] = 0xff;
 
 	gss_krb5_make_confounder(msg_start, conflen);
 
@@ -438,7 +444,7 @@ gss_wrap_kerberos_v2(struct krb5_ctx *kctx, u32 offset,
 	u8		*ptr, *plainhdr;
 	s32		now;
 	u8		flags = 0x00;
-	__be16		*be16ptr, ec = 0;
+	__be16		*be16ptr;
 	__be64		*be64ptr;
 	u32		err;
 
@@ -468,16 +474,16 @@ gss_wrap_kerberos_v2(struct krb5_ctx *kctx, u32 offset,
 	be16ptr = (__be16 *)ptr;
 
 	blocksize = crypto_blkcipher_blocksize(kctx->acceptor_enc);
-	*be16ptr++ = cpu_to_be16(ec);
+	*be16ptr++ = 0;
 	/* "inner" token header always uses 0 for RRC */
-	*be16ptr++ = cpu_to_be16(0);
+	*be16ptr++ = 0;
 
 	be64ptr = (__be64 *)be16ptr;
 	spin_lock(&krb5_seq_lock);
 	*be64ptr = cpu_to_be64(kctx->seq_send64++);
 	spin_unlock(&krb5_seq_lock);
 
-	err = (*kctx->gk5e->encrypt_v2)(kctx, offset, buf, ec, pages);
+	err = (*kctx->gk5e->encrypt_v2)(kctx, offset, buf, pages);
 	if (err)
 		return err;
 
diff --git a/net/sunrpc/auth_null.c b/net/sunrpc/auth_null.c
index f0ebe07..712c123 100644
--- a/net/sunrpc/auth_null.c
+++ b/net/sunrpc/auth_null.c
@@ -35,6 +35,8 @@ nul_destroy(struct rpc_auth *auth)
 static struct rpc_cred *
 nul_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
 {
+	if (flags & RPCAUTH_LOOKUP_RCU)
+		return &null_cred;
 	return get_rpccred(&null_cred);
 }
 
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 2e6ab10..488ddee 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -1746,6 +1746,7 @@ call_bind_status(struct rpc_task *task)
 	case -EHOSTDOWN:
 	case -EHOSTUNREACH:
 	case -ENETUNREACH:
+	case -ENOBUFS:
 	case -EPIPE:
 		dprintk("RPC: %5u remote rpcbind unreachable: %d\n",
 				task->tk_pid, task->tk_status);
@@ -1812,6 +1813,8 @@ call_connect_status(struct rpc_task *task)
 	case -ECONNABORTED:
 	case -ENETUNREACH:
 	case -EHOSTUNREACH:
+	case -ENOBUFS:
+	case -EPIPE:
 		if (RPC_IS_SOFTCONN(task))
 			break;
 		/* retry with existing socket, after a delay */
@@ -1918,6 +1921,7 @@ call_transmit_status(struct rpc_task *task)
 	case -ECONNRESET:
 	case -ECONNABORTED:
 	case -ENOTCONN:
+	case -ENOBUFS:
 	case -EPIPE:
 		rpc_task_force_reencode(task);
 	}
@@ -2034,6 +2038,7 @@ call_status(struct rpc_task *task)
 	case -ECONNRESET:
 	case -ECONNABORTED:
 		rpc_force_rebind(clnt);
+	case -ENOBUFS:
 		rpc_delay(task, 3*HZ);
 	case -EPIPE:
 	case -ENOTCONN:
diff --git a/net/sunrpc/rpc_pipe.c b/net/sunrpc/rpc_pipe.c
index b185548..2d12b76 100644
--- a/net/sunrpc/rpc_pipe.c
+++ b/net/sunrpc/rpc_pipe.c
@@ -195,7 +195,7 @@ static struct inode *
 rpc_alloc_inode(struct super_block *sb)
 {
 	struct rpc_inode *rpci;
-	rpci = (struct rpc_inode *)kmem_cache_alloc(rpc_inode_cachep, GFP_KERNEL);
+	rpci = kmem_cache_alloc(rpc_inode_cachep, GFP_KERNEL);
 	if (!rpci)
 		return NULL;
 	return &rpci->vfs_inode;
diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
index 51c6316..56e4e15 100644
--- a/net/sunrpc/xprt.c
+++ b/net/sunrpc/xprt.c
@@ -744,6 +744,7 @@ static void xprt_connect_status(struct rpc_task *task)
 	case -ECONNABORTED:
 	case -ENETUNREACH:
 	case -EHOSTUNREACH:
+	case -EPIPE:
 	case -EAGAIN:
 		dprintk("RPC: %5u xprt_connect_status: retrying\n", task->tk_pid);
 		break;
diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c
index 693966d..6166c98 100644
--- a/net/sunrpc/xprtrdma/rpc_rdma.c
+++ b/net/sunrpc/xprtrdma/rpc_rdma.c
@@ -53,14 +53,6 @@
 # define RPCDBG_FACILITY	RPCDBG_TRANS
 #endif
 
-enum rpcrdma_chunktype {
-	rpcrdma_noch = 0,
-	rpcrdma_readch,
-	rpcrdma_areadch,
-	rpcrdma_writech,
-	rpcrdma_replych
-};
-
 #ifdef RPC_DEBUG
 static const char transfertypes[][12] = {
 	"pure inline",	/* no chunks */
@@ -279,13 +271,37 @@ rpcrdma_create_chunks(struct rpc_rqst *rqst, struct xdr_buf *target,
 	return (unsigned char *)iptr - (unsigned char *)headerp;
 
 out:
-	for (pos = 0; nchunks--;)
-		pos += rpcrdma_deregister_external(
-				&req->rl_segments[pos], r_xprt);
+	if (r_xprt->rx_ia.ri_memreg_strategy != RPCRDMA_FRMR) {
+		for (pos = 0; nchunks--;)
+			pos += rpcrdma_deregister_external(
+					&req->rl_segments[pos], r_xprt);
+	}
 	return n;
 }
 
 /*
+ * Marshal chunks. This routine returns the header length
+ * consumed by marshaling.
+ *
+ * Returns positive RPC/RDMA header size, or negative errno.
+ */
+
+ssize_t
+rpcrdma_marshal_chunks(struct rpc_rqst *rqst, ssize_t result)
+{
+	struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
+	struct rpcrdma_msg *headerp = (struct rpcrdma_msg *)req->rl_base;
+
+	if (req->rl_rtype != rpcrdma_noch)
+		result = rpcrdma_create_chunks(rqst, &rqst->rq_snd_buf,
+					       headerp, req->rl_rtype);
+	else if (req->rl_wtype != rpcrdma_noch)
+		result = rpcrdma_create_chunks(rqst, &rqst->rq_rcv_buf,
+					       headerp, req->rl_wtype);
+	return result;
+}
+
+/*
  * Copy write data inline.
  * This function is used for "small" requests. Data which is passed
  * to RPC via iovecs (or page list) is copied directly into the
@@ -377,7 +393,6 @@ rpcrdma_marshal_req(struct rpc_rqst *rqst)
 	char *base;
 	size_t rpclen, padlen;
 	ssize_t hdrlen;
-	enum rpcrdma_chunktype rtype, wtype;
 	struct rpcrdma_msg *headerp;
 
 	/*
@@ -415,13 +430,13 @@ rpcrdma_marshal_req(struct rpc_rqst *rqst)
 	 * into pages; otherwise use reply chunks.
 	 */
 	if (rqst->rq_rcv_buf.buflen <= RPCRDMA_INLINE_READ_THRESHOLD(rqst))
-		wtype = rpcrdma_noch;
+		req->rl_wtype = rpcrdma_noch;
 	else if (rqst->rq_rcv_buf.page_len == 0)
-		wtype = rpcrdma_replych;
+		req->rl_wtype = rpcrdma_replych;
 	else if (rqst->rq_rcv_buf.flags & XDRBUF_READ)
-		wtype = rpcrdma_writech;
+		req->rl_wtype = rpcrdma_writech;
 	else
-		wtype = rpcrdma_replych;
+		req->rl_wtype = rpcrdma_replych;
 
 	/*
 	 * Chunks needed for arguments?
@@ -438,16 +453,16 @@ rpcrdma_marshal_req(struct rpc_rqst *rqst)
 	 * TBD check NFSv4 setacl
 	 */
 	if (rqst->rq_snd_buf.len <= RPCRDMA_INLINE_WRITE_THRESHOLD(rqst))
-		rtype = rpcrdma_noch;
+		req->rl_rtype = rpcrdma_noch;
 	else if (rqst->rq_snd_buf.page_len == 0)
-		rtype = rpcrdma_areadch;
+		req->rl_rtype = rpcrdma_areadch;
 	else
-		rtype = rpcrdma_readch;
+		req->rl_rtype = rpcrdma_readch;
 
 	/* The following simplification is not true forever */
-	if (rtype != rpcrdma_noch && wtype == rpcrdma_replych)
-		wtype = rpcrdma_noch;
-	if (rtype != rpcrdma_noch && wtype != rpcrdma_noch) {
+	if (req->rl_rtype != rpcrdma_noch && req->rl_wtype == rpcrdma_replych)
+		req->rl_wtype = rpcrdma_noch;
+	if (req->rl_rtype != rpcrdma_noch && req->rl_wtype != rpcrdma_noch) {
 		dprintk("RPC:       %s: cannot marshal multiple chunk lists\n",
 			__func__);
 		return -EIO;
@@ -461,7 +476,7 @@ rpcrdma_marshal_req(struct rpc_rqst *rqst)
 	 * When padding is in use and applies to the transfer, insert
 	 * it and change the message type.
 	 */
-	if (rtype == rpcrdma_noch) {
+	if (req->rl_rtype == rpcrdma_noch) {
 
 		padlen = rpcrdma_inline_pullup(rqst,
 						RPCRDMA_INLINE_PAD_VALUE(rqst));
@@ -476,7 +491,7 @@ rpcrdma_marshal_req(struct rpc_rqst *rqst)
 			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) {
+			if (req->rl_wtype != rpcrdma_noch) {
 				dprintk("RPC:       %s: invalid chunk list\n",
 					__func__);
 				return -EIO;
@@ -497,30 +512,18 @@ rpcrdma_marshal_req(struct rpc_rqst *rqst)
 			 * on receive. Therefore, we request a reply chunk
 			 * for non-writes wherever feasible and efficient.
 			 */
-			if (wtype == rpcrdma_noch)
-				wtype = rpcrdma_replych;
+			if (req->rl_wtype == rpcrdma_noch)
+				req->rl_wtype = rpcrdma_replych;
 		}
 	}
 
-	/*
-	 * Marshal chunks. This routine will return the header length
-	 * consumed by marshaling.
-	 */
-	if (rtype != rpcrdma_noch) {
-		hdrlen = rpcrdma_create_chunks(rqst,
-					&rqst->rq_snd_buf, headerp, rtype);
-		wtype = rtype;	/* simplify dprintk */
-
-	} else if (wtype != rpcrdma_noch) {
-		hdrlen = rpcrdma_create_chunks(rqst,
-					&rqst->rq_rcv_buf, headerp, wtype);
-	}
+	hdrlen = rpcrdma_marshal_chunks(rqst, hdrlen);
 	if (hdrlen < 0)
 		return hdrlen;
 
 	dprintk("RPC:       %s: %s: hdrlen %zd rpclen %zd padlen %zd"
 		" headerp 0x%p base 0x%p lkey 0x%x\n",
-		__func__, transfertypes[wtype], hdrlen, rpclen, padlen,
+		__func__, transfertypes[req->rl_wtype], hdrlen, rpclen, padlen,
 		headerp, base, req->rl_iov.lkey);
 
 	/*
diff --git a/net/sunrpc/xprtrdma/transport.c b/net/sunrpc/xprtrdma/transport.c
index 66f91f0..2faac49 100644
--- a/net/sunrpc/xprtrdma/transport.c
+++ b/net/sunrpc/xprtrdma/transport.c
@@ -296,7 +296,6 @@ xprt_setup_rdma(struct xprt_create *args)
 
 	xprt->resvport = 0;		/* privileged port not needed */
 	xprt->tsh_size = 0;		/* RPC-RDMA handles framing */
-	xprt->max_payload = RPCRDMA_MAX_DATA_SEGS * PAGE_SIZE;
 	xprt->ops = &xprt_rdma_procs;
 
 	/*
@@ -382,6 +381,9 @@ xprt_setup_rdma(struct xprt_create *args)
 	new_ep->rep_xprt = xprt;
 
 	xprt_rdma_format_addresses(xprt);
+	xprt->max_payload = rpcrdma_max_payload(new_xprt);
+	dprintk("RPC:       %s: transport data payload maximum: %zu bytes\n",
+		__func__, xprt->max_payload);
 
 	if (!try_module_get(THIS_MODULE))
 		goto out4;
@@ -412,7 +414,7 @@ xprt_rdma_close(struct rpc_xprt *xprt)
 	if (r_xprt->rx_ep.rep_connected > 0)
 		xprt->reestablish_timeout = 0;
 	xprt_disconnect_done(xprt);
-	(void) rpcrdma_ep_disconnect(&r_xprt->rx_ep, &r_xprt->rx_ia);
+	rpcrdma_ep_disconnect(&r_xprt->rx_ep, &r_xprt->rx_ia);
 }
 
 static void
@@ -595,13 +597,14 @@ xprt_rdma_send_request(struct rpc_task *task)
 	struct rpc_xprt *xprt = rqst->rq_xprt;
 	struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
 	struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
-	int rc;
+	int rc = 0;
 
-	if (req->rl_niovs == 0) {
+	if (req->rl_niovs == 0)
 		rc = rpcrdma_marshal_req(rqst);
-		if (rc < 0)
-			goto failed_marshal;
-	}
+	else if (r_xprt->rx_ia.ri_memreg_strategy == RPCRDMA_FRMR)
+		rc = rpcrdma_marshal_chunks(rqst, 0);
+	if (rc < 0)
+		goto failed_marshal;
 
 	if (req->rl_reply == NULL) 		/* e.g. reconnection */
 		rpcrdma_recv_buffer_get(req);
diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index 13dbd1c..61c4129 100644
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -61,6 +61,8 @@
 # define RPCDBG_FACILITY	RPCDBG_TRANS
 #endif
 
+static void rpcrdma_reset_frmrs(struct rpcrdma_ia *);
+
 /*
  * internal functions
  */
@@ -103,17 +105,6 @@ rpcrdma_run_tasklet(unsigned long data)
 
 static DECLARE_TASKLET(rpcrdma_tasklet_g, rpcrdma_run_tasklet, 0UL);
 
-static inline void
-rpcrdma_schedule_tasklet(struct rpcrdma_rep *rep)
-{
-	unsigned long flags;
-
-	spin_lock_irqsave(&rpcrdma_tk_lock_g, flags);
-	list_add_tail(&rep->rr_list, &rpcrdma_tasklets_g);
-	spin_unlock_irqrestore(&rpcrdma_tk_lock_g, flags);
-	tasklet_schedule(&rpcrdma_tasklet_g);
-}
-
 static void
 rpcrdma_qp_async_error_upcall(struct ib_event *event, void *context)
 {
@@ -153,12 +144,7 @@ rpcrdma_sendcq_process_wc(struct ib_wc *wc)
 	if (wc->wr_id == 0ULL)
 		return;
 	if (wc->status != IB_WC_SUCCESS)
-		return;
-
-	if (wc->opcode == IB_WC_FAST_REG_MR)
-		frmr->r.frmr.state = FRMR_IS_VALID;
-	else if (wc->opcode == IB_WC_LOCAL_INV)
-		frmr->r.frmr.state = FRMR_IS_INVALID;
+		frmr->r.frmr.fr_state = FRMR_IS_STALE;
 }
 
 static int
@@ -217,7 +203,7 @@ rpcrdma_sendcq_upcall(struct ib_cq *cq, void *cq_context)
 }
 
 static void
-rpcrdma_recvcq_process_wc(struct ib_wc *wc)
+rpcrdma_recvcq_process_wc(struct ib_wc *wc, struct list_head *sched_list)
 {
 	struct rpcrdma_rep *rep =
 			(struct rpcrdma_rep *)(unsigned long)wc->wr_id;
@@ -248,28 +234,38 @@ rpcrdma_recvcq_process_wc(struct ib_wc *wc)
 	}
 
 out_schedule:
-	rpcrdma_schedule_tasklet(rep);
+	list_add_tail(&rep->rr_list, sched_list);
 }
 
 static int
 rpcrdma_recvcq_poll(struct ib_cq *cq, struct rpcrdma_ep *ep)
 {
+	struct list_head sched_list;
 	struct ib_wc *wcs;
 	int budget, count, rc;
+	unsigned long flags;
 
+	INIT_LIST_HEAD(&sched_list);
 	budget = RPCRDMA_WC_BUDGET / RPCRDMA_POLLSIZE;
 	do {
 		wcs = ep->rep_recv_wcs;
 
 		rc = ib_poll_cq(cq, RPCRDMA_POLLSIZE, wcs);
 		if (rc <= 0)
-			return rc;
+			goto out_schedule;
 
 		count = rc;
 		while (count-- > 0)
-			rpcrdma_recvcq_process_wc(wcs++);
+			rpcrdma_recvcq_process_wc(wcs++, &sched_list);
 	} while (rc == RPCRDMA_POLLSIZE && --budget);
-	return 0;
+	rc = 0;
+
+out_schedule:
+	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);
+	return rc;
 }
 
 /*
@@ -310,6 +306,13 @@ rpcrdma_recvcq_upcall(struct ib_cq *cq, void *cq_context)
 	rpcrdma_recvcq_poll(cq, ep);
 }
 
+static void
+rpcrdma_flush_cqs(struct rpcrdma_ep *ep)
+{
+	rpcrdma_recvcq_upcall(ep->rep_attr.recv_cq, ep);
+	rpcrdma_sendcq_upcall(ep->rep_attr.send_cq, ep);
+}
+
 #ifdef RPC_DEBUG
 static const char * const conn[] = {
 	"address resolved",
@@ -323,8 +326,16 @@ static const char * const conn[] = {
 	"rejected",
 	"established",
 	"disconnected",
-	"device removal"
+	"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
@@ -382,23 +393,18 @@ rpcrdma_conn_upcall(struct rdma_cm_id *id, struct rdma_cm_event *event)
 	case RDMA_CM_EVENT_DEVICE_REMOVAL:
 		connstate = -ENODEV;
 connected:
-		dprintk("RPC:       %s: %s: %pI4:%u (ep 0x%p event 0x%x)\n",
-			__func__,
-			(event->event <= 11) ? conn[event->event] :
-						"unknown connection error",
-			&addr->sin_addr.s_addr,
-			ntohs(addr->sin_port),
-			ep, event->event);
 		atomic_set(&rpcx_to_rdmax(ep->rep_xprt)->rx_buf.rb_credits, 1);
 		dprintk("RPC:       %s: %sconnected\n",
 					__func__, connstate > 0 ? "" : "dis");
 		ep->rep_connected = connstate;
 		ep->rep_func(ep);
 		wake_up_all(&ep->rep_connect_wait);
-		break;
+		/*FALLTHROUGH*/
 	default:
-		dprintk("RPC:       %s: unexpected CM event %d\n",
-			__func__, event->event);
+		dprintk("RPC:       %s: %pI4:%u (ep 0x%p): %s\n",
+			__func__, &addr->sin_addr.s_addr,
+			ntohs(addr->sin_port), ep,
+			CONNECTION_MSG(event->event));
 		break;
 	}
 
@@ -558,12 +564,7 @@ rpcrdma_ia_open(struct rpcrdma_xprt *xprt, struct sockaddr *addr, int memreg)
 		if (!ia->ri_id->device->alloc_fmr) {
 			dprintk("RPC:       %s: MTHCAFMR registration "
 				"not supported by HCA\n", __func__);
-#if RPCRDMA_PERSISTENT_REGISTRATION
 			memreg = RPCRDMA_ALLPHYSICAL;
-#else
-			rc = -ENOMEM;
-			goto out2;
-#endif
 		}
 	}
 
@@ -578,20 +579,16 @@ rpcrdma_ia_open(struct rpcrdma_xprt *xprt, struct sockaddr *addr, int memreg)
 	switch (memreg) {
 	case RPCRDMA_FRMR:
 		break;
-#if RPCRDMA_PERSISTENT_REGISTRATION
 	case RPCRDMA_ALLPHYSICAL:
 		mem_priv = IB_ACCESS_LOCAL_WRITE |
 				IB_ACCESS_REMOTE_WRITE |
 				IB_ACCESS_REMOTE_READ;
 		goto register_setup;
-#endif
 	case RPCRDMA_MTHCAFMR:
 		if (ia->ri_have_dma_lkey)
 			break;
 		mem_priv = IB_ACCESS_LOCAL_WRITE;
-#if RPCRDMA_PERSISTENT_REGISTRATION
 	register_setup:
-#endif
 		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 "
@@ -613,6 +610,7 @@ rpcrdma_ia_open(struct rpcrdma_xprt *xprt, struct sockaddr *addr, int memreg)
 	/* Else will do memory reg/dereg for each chunk */
 	ia->ri_memreg_strategy = memreg;
 
+	rwlock_init(&ia->ri_qplock);
 	return 0;
 out2:
 	rdma_destroy_id(ia->ri_id);
@@ -826,10 +824,7 @@ rpcrdma_ep_destroy(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
 	cancel_delayed_work_sync(&ep->rep_connect_worker);
 
 	if (ia->ri_id->qp) {
-		rc = rpcrdma_ep_disconnect(ep, ia);
-		if (rc)
-			dprintk("RPC:       %s: rpcrdma_ep_disconnect"
-				" returned %i\n", __func__, rc);
+		rpcrdma_ep_disconnect(ep, ia);
 		rdma_destroy_qp(ia->ri_id);
 		ia->ri_id->qp = NULL;
 	}
@@ -859,7 +854,7 @@ rpcrdma_ep_destroy(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
 int
 rpcrdma_ep_connect(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
 {
-	struct rdma_cm_id *id;
+	struct rdma_cm_id *id, *old;
 	int rc = 0;
 	int retry_count = 0;
 
@@ -867,13 +862,12 @@ rpcrdma_ep_connect(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
 		struct rpcrdma_xprt *xprt;
 retry:
 		dprintk("RPC:       %s: reconnecting...\n", __func__);
-		rc = rpcrdma_ep_disconnect(ep, ia);
-		if (rc && rc != -ENOTCONN)
-			dprintk("RPC:       %s: rpcrdma_ep_disconnect"
-				" status %i\n", __func__, rc);
 
-		rpcrdma_clean_cq(ep->rep_attr.recv_cq);
-		rpcrdma_clean_cq(ep->rep_attr.send_cq);
+		rpcrdma_ep_disconnect(ep, ia);
+		rpcrdma_flush_cqs(ep);
+
+		if (ia->ri_memreg_strategy == RPCRDMA_FRMR)
+			rpcrdma_reset_frmrs(ia);
 
 		xprt = container_of(ia, struct rpcrdma_xprt, rx_ia);
 		id = rpcrdma_create_id(xprt, ia,
@@ -905,9 +899,14 @@ retry:
 			rc = -ENETUNREACH;
 			goto out;
 		}
-		rdma_destroy_qp(ia->ri_id);
-		rdma_destroy_id(ia->ri_id);
+
+		write_lock(&ia->ri_qplock);
+		old = ia->ri_id;
 		ia->ri_id = id;
+		write_unlock(&ia->ri_qplock);
+
+		rdma_destroy_qp(old);
+		rdma_destroy_id(old);
 	} else {
 		dprintk("RPC:       %s: connecting...\n", __func__);
 		rc = rdma_create_qp(ia->ri_id, ia->ri_pd, &ep->rep_attr);
@@ -974,13 +973,12 @@ out:
  * This call is not reentrant, and must not be made in parallel
  * on the same endpoint.
  */
-int
+void
 rpcrdma_ep_disconnect(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
 {
 	int rc;
 
-	rpcrdma_clean_cq(ep->rep_attr.recv_cq);
-	rpcrdma_clean_cq(ep->rep_attr.send_cq);
+	rpcrdma_flush_cqs(ep);
 	rc = rdma_disconnect(ia->ri_id);
 	if (!rc) {
 		/* returns without wait if not connected */
@@ -992,12 +990,93 @@ rpcrdma_ep_disconnect(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
 		dprintk("RPC:       %s: rdma_disconnect %i\n", __func__, rc);
 		ep->rep_connected = rc;
 	}
+}
+
+static int
+rpcrdma_init_fmrs(struct rpcrdma_ia *ia, struct rpcrdma_buffer *buf)
+{
+	int mr_access_flags = IB_ACCESS_REMOTE_WRITE | IB_ACCESS_REMOTE_READ;
+	struct ib_fmr_attr fmr_attr = {
+		.max_pages	= RPCRDMA_MAX_DATA_SEGS,
+		.max_maps	= 1,
+		.page_shift	= PAGE_SHIFT
+	};
+	struct rpcrdma_mw *r;
+	int i, rc;
+
+	i = (buf->rb_max_requests + 1) * RPCRDMA_MAX_SEGS;
+	dprintk("RPC:       %s: initalizing %d FMRs\n", __func__, i);
+
+	while (i--) {
+		r = kzalloc(sizeof(*r), GFP_KERNEL);
+		if (r == NULL)
+			return -ENOMEM;
+
+		r->r.fmr = ib_alloc_fmr(ia->ri_pd, mr_access_flags, &fmr_attr);
+		if (IS_ERR(r->r.fmr)) {
+			rc = PTR_ERR(r->r.fmr);
+			dprintk("RPC:       %s: ib_alloc_fmr failed %i\n",
+				__func__, rc);
+			goto out_free;
+		}
+
+		list_add(&r->mw_list, &buf->rb_mws);
+		list_add(&r->mw_all, &buf->rb_all);
+	}
+	return 0;
+
+out_free:
+	kfree(r);
+	return rc;
+}
+
+static int
+rpcrdma_init_frmrs(struct rpcrdma_ia *ia, struct rpcrdma_buffer *buf)
+{
+	struct rpcrdma_frmr *f;
+	struct rpcrdma_mw *r;
+	int i, rc;
+
+	i = (buf->rb_max_requests + 1) * RPCRDMA_MAX_SEGS;
+	dprintk("RPC:       %s: initalizing %d FRMRs\n", __func__, i);
+
+	while (i--) {
+		r = kzalloc(sizeof(*r), GFP_KERNEL);
+		if (r == NULL)
+			return -ENOMEM;
+		f = &r->r.frmr;
+
+		f->fr_mr = ib_alloc_fast_reg_mr(ia->ri_pd,
+						ia->ri_max_frmr_depth);
+		if (IS_ERR(f->fr_mr)) {
+			rc = PTR_ERR(f->fr_mr);
+			dprintk("RPC:       %s: ib_alloc_fast_reg_mr "
+				"failed %i\n", __func__, rc);
+			goto out_free;
+		}
+
+		f->fr_pgl = ib_alloc_fast_reg_page_list(ia->ri_id->device,
+							ia->ri_max_frmr_depth);
+		if (IS_ERR(f->fr_pgl)) {
+			rc = PTR_ERR(f->fr_pgl);
+			dprintk("RPC:       %s: ib_alloc_fast_reg_page_list "
+				"failed %i\n", __func__, rc);
+
+			ib_dereg_mr(f->fr_mr);
+			goto out_free;
+		}
+
+		list_add(&r->mw_list, &buf->rb_mws);
+		list_add(&r->mw_all, &buf->rb_all);
+	}
+
+	return 0;
+
+out_free:
+	kfree(r);
 	return rc;
 }
 
-/*
- * Initialize buffer memory
- */
 int
 rpcrdma_buffer_create(struct rpcrdma_buffer *buf, struct rpcrdma_ep *ep,
 	struct rpcrdma_ia *ia, struct rpcrdma_create_data_internal *cdata)
@@ -1005,7 +1084,6 @@ rpcrdma_buffer_create(struct rpcrdma_buffer *buf, struct rpcrdma_ep *ep,
 	char *p;
 	size_t len, rlen, wlen;
 	int i, rc;
-	struct rpcrdma_mw *r;
 
 	buf->rb_max_requests = cdata->max_requests;
 	spin_lock_init(&buf->rb_lock);
@@ -1016,28 +1094,12 @@ rpcrdma_buffer_create(struct rpcrdma_buffer *buf, struct rpcrdma_ep *ep,
 	 *   2.  arrays of struct rpcrdma_req to fill in pointers
 	 *   3.  array of struct rpcrdma_rep for replies
 	 *   4.  padding, if any
-	 *   5.  mw's, fmr's or frmr's, if any
 	 * Send/recv buffers in req/rep need to be registered
 	 */
-
 	len = buf->rb_max_requests *
 		(sizeof(struct rpcrdma_req *) + sizeof(struct rpcrdma_rep *));
 	len += cdata->padding;
-	switch (ia->ri_memreg_strategy) {
-	case RPCRDMA_FRMR:
-		len += buf->rb_max_requests * RPCRDMA_MAX_SEGS *
-				sizeof(struct rpcrdma_mw);
-		break;
-	case RPCRDMA_MTHCAFMR:
-		/* TBD we are perhaps overallocating here */
-		len += (buf->rb_max_requests + 1) * RPCRDMA_MAX_SEGS *
-				sizeof(struct rpcrdma_mw);
-		break;
-	default:
-		break;
-	}
 
-	/* allocate 1, 4 and 5 in one shot */
 	p = kzalloc(len, GFP_KERNEL);
 	if (p == NULL) {
 		dprintk("RPC:       %s: req_t/rep_t/pad kzalloc(%zd) failed\n",
@@ -1064,51 +1126,17 @@ rpcrdma_buffer_create(struct rpcrdma_buffer *buf, struct rpcrdma_ep *ep,
 	p += cdata->padding;
 
 	INIT_LIST_HEAD(&buf->rb_mws);
-	r = (struct rpcrdma_mw *)p;
+	INIT_LIST_HEAD(&buf->rb_all);
 	switch (ia->ri_memreg_strategy) {
 	case RPCRDMA_FRMR:
-		for (i = buf->rb_max_requests * RPCRDMA_MAX_SEGS; i; i--) {
-			r->r.frmr.fr_mr = ib_alloc_fast_reg_mr(ia->ri_pd,
-						ia->ri_max_frmr_depth);
-			if (IS_ERR(r->r.frmr.fr_mr)) {
-				rc = PTR_ERR(r->r.frmr.fr_mr);
-				dprintk("RPC:       %s: ib_alloc_fast_reg_mr"
-					" failed %i\n", __func__, rc);
-				goto out;
-			}
-			r->r.frmr.fr_pgl = ib_alloc_fast_reg_page_list(
-						ia->ri_id->device,
-						ia->ri_max_frmr_depth);
-			if (IS_ERR(r->r.frmr.fr_pgl)) {
-				rc = PTR_ERR(r->r.frmr.fr_pgl);
-				dprintk("RPC:       %s: "
-					"ib_alloc_fast_reg_page_list "
-					"failed %i\n", __func__, rc);
-
-				ib_dereg_mr(r->r.frmr.fr_mr);
-				goto out;
-			}
-			list_add(&r->mw_list, &buf->rb_mws);
-			++r;
-		}
+		rc = rpcrdma_init_frmrs(ia, buf);
+		if (rc)
+			goto out;
 		break;
 	case RPCRDMA_MTHCAFMR:
-		/* TBD we are perhaps overallocating here */
-		for (i = (buf->rb_max_requests+1) * RPCRDMA_MAX_SEGS; i; i--) {
-			static struct ib_fmr_attr fa =
-				{ RPCRDMA_MAX_DATA_SEGS, 1, PAGE_SHIFT };
-			r->r.fmr = ib_alloc_fmr(ia->ri_pd,
-				IB_ACCESS_REMOTE_WRITE | IB_ACCESS_REMOTE_READ,
-				&fa);
-			if (IS_ERR(r->r.fmr)) {
-				rc = PTR_ERR(r->r.fmr);
-				dprintk("RPC:       %s: ib_alloc_fmr"
-					" failed %i\n", __func__, rc);
-				goto out;
-			}
-			list_add(&r->mw_list, &buf->rb_mws);
-			++r;
-		}
+		rc = rpcrdma_init_fmrs(ia, buf);
+		if (rc)
+			goto out;
 		break;
 	default:
 		break;
@@ -1176,24 +1204,57 @@ out:
 	return rc;
 }
 
-/*
- * Unregister and destroy buffer memory. Need to deal with
- * partial initialization, so it's callable from failed create.
- * Must be called before destroying endpoint, as registrations
- * reference it.
- */
+static void
+rpcrdma_destroy_fmrs(struct rpcrdma_buffer *buf)
+{
+	struct rpcrdma_mw *r;
+	int rc;
+
+	while (!list_empty(&buf->rb_all)) {
+		r = list_entry(buf->rb_all.next, struct rpcrdma_mw, mw_all);
+		list_del(&r->mw_all);
+		list_del(&r->mw_list);
+
+		rc = ib_dealloc_fmr(r->r.fmr);
+		if (rc)
+			dprintk("RPC:       %s: ib_dealloc_fmr failed %i\n",
+				__func__, rc);
+
+		kfree(r);
+	}
+}
+
+static void
+rpcrdma_destroy_frmrs(struct rpcrdma_buffer *buf)
+{
+	struct rpcrdma_mw *r;
+	int rc;
+
+	while (!list_empty(&buf->rb_all)) {
+		r = list_entry(buf->rb_all.next, struct rpcrdma_mw, mw_all);
+		list_del(&r->mw_all);
+		list_del(&r->mw_list);
+
+		rc = ib_dereg_mr(r->r.frmr.fr_mr);
+		if (rc)
+			dprintk("RPC:       %s: ib_dereg_mr failed %i\n",
+				__func__, rc);
+		ib_free_fast_reg_page_list(r->r.frmr.fr_pgl);
+
+		kfree(r);
+	}
+}
+
 void
 rpcrdma_buffer_destroy(struct rpcrdma_buffer *buf)
 {
-	int rc, i;
 	struct rpcrdma_ia *ia = rdmab_to_ia(buf);
-	struct rpcrdma_mw *r;
+	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.  padding (if any) [moved to rpcrdma_ep_destroy]
-	 *   4.  arrays
+	 *   3.  MWs
 	 */
 	dprintk("RPC:       %s: entering\n", __func__);
 
@@ -1212,34 +1273,217 @@ rpcrdma_buffer_destroy(struct rpcrdma_buffer *buf)
 		}
 	}
 
+	switch (ia->ri_memreg_strategy) {
+	case RPCRDMA_FRMR:
+		rpcrdma_destroy_frmrs(buf);
+		break;
+	case RPCRDMA_MTHCAFMR:
+		rpcrdma_destroy_fmrs(buf);
+		break;
+	default:
+		break;
+	}
+
+	kfree(buf->rb_pool);
+}
+
+/* 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
+rpcrdma_reset_frmrs(struct rpcrdma_ia *ia)
+{
+	struct rpcrdma_xprt *r_xprt =
+				container_of(ia, struct rpcrdma_xprt, rx_ia);
+	struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
+	struct list_head *pos;
+	struct rpcrdma_mw *r;
+	int rc;
+
+	list_for_each(pos, &buf->rb_all) {
+		r = list_entry(pos, struct rpcrdma_mw, mw_all);
+
+		if (r->r.frmr.fr_state == FRMR_IS_INVALID)
+			continue;
+
+		rc = ib_dereg_mr(r->r.frmr.fr_mr);
+		if (rc)
+			dprintk("RPC:       %s: ib_dereg_mr failed %i\n",
+				__func__, rc);
+		ib_free_fast_reg_page_list(r->r.frmr.fr_pgl);
+
+		r->r.frmr.fr_mr = ib_alloc_fast_reg_mr(ia->ri_pd,
+					ia->ri_max_frmr_depth);
+		if (IS_ERR(r->r.frmr.fr_mr)) {
+			rc = PTR_ERR(r->r.frmr.fr_mr);
+			dprintk("RPC:       %s: ib_alloc_fast_reg_mr"
+				" failed %i\n", __func__, rc);
+			continue;
+		}
+		r->r.frmr.fr_pgl = ib_alloc_fast_reg_page_list(
+					ia->ri_id->device,
+					ia->ri_max_frmr_depth);
+		if (IS_ERR(r->r.frmr.fr_pgl)) {
+			rc = PTR_ERR(r->r.frmr.fr_pgl);
+			dprintk("RPC:       %s: "
+				"ib_alloc_fast_reg_page_list "
+				"failed %i\n", __func__, rc);
+
+			ib_dereg_mr(r->r.frmr.fr_mr);
+			continue;
+		}
+		r->r.frmr.fr_state = FRMR_IS_INVALID;
+	}
+}
+
+/* "*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;
+	}
+}
+
+/* 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;
+
+	for (i = 1, seg++; i < RPCRDMA_MAX_SEGS; seg++, i++)
+		rpcrdma_buffer_put_mr(&seg->mr_chunk.rl_mw, buf);
+	rpcrdma_buffer_put_mr(&seg1->mr_chunk.rl_mw, buf);
+}
+
+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;
+	}
+}
+
+/* rpcrdma_unmap_one() was already done by rpcrdma_deregister_frmr_external().
+ * 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);
+			       struct rpcrdma_mw, mw_list);
 		list_del(&r->mw_list);
-		switch (ia->ri_memreg_strategy) {
-		case RPCRDMA_FRMR:
-			rc = ib_dereg_mr(r->r.frmr.fr_mr);
-			if (rc)
-				dprintk("RPC:       %s:"
-					" ib_dereg_mr"
-					" failed %i\n",
-					__func__, rc);
-			ib_free_fast_reg_page_list(r->r.frmr.fr_pgl);
-			break;
-		case RPCRDMA_MTHCAFMR:
-			rc = ib_dealloc_fmr(r->r.fmr);
-			if (rc)
-				dprintk("RPC:       %s:"
-					" ib_dealloc_fmr"
-					" failed %i\n",
-					__func__, rc);
-			break;
-		default:
-			break;
+		if (r->r.frmr.fr_state == FRMR_IS_STALE) {
+			list_add(&r->mw_list, stale);
+			continue;
 		}
+		req->rl_segments[i].mr_chunk.rl_mw = r;
+		if (unlikely(i-- == 0))
+			return req;	/* Success */
 	}
 
-	kfree(buf->rb_pool);
+	/* 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].mr_chunk.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;
 }
 
 /*
@@ -1254,10 +1498,10 @@ rpcrdma_buffer_destroy(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;
-	int i;
-	struct rpcrdma_mw *r;
 
 	spin_lock_irqsave(&buffers->rb_lock, flags);
 	if (buffers->rb_send_index == buffers->rb_max_requests) {
@@ -1277,16 +1521,21 @@ rpcrdma_buffer_get(struct rpcrdma_buffer *buffers)
 		buffers->rb_recv_bufs[buffers->rb_recv_index++] = NULL;
 	}
 	buffers->rb_send_bufs[buffers->rb_send_index++] = NULL;
-	if (!list_empty(&buffers->rb_mws)) {
-		i = RPCRDMA_MAX_SEGS - 1;
-		do {
-			r = list_entry(buffers->rb_mws.next,
-					struct rpcrdma_mw, mw_list);
-			list_del(&r->mw_list);
-			req->rl_segments[i].mr_chunk.rl_mw = r;
-		} while (--i >= 0);
+
+	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;
 }
 
@@ -1299,34 +1548,14 @@ rpcrdma_buffer_put(struct rpcrdma_req *req)
 {
 	struct rpcrdma_buffer *buffers = req->rl_buffer;
 	struct rpcrdma_ia *ia = rdmab_to_ia(buffers);
-	int i;
 	unsigned long flags;
 
 	spin_lock_irqsave(&buffers->rb_lock, flags);
-	buffers->rb_send_bufs[--buffers->rb_send_index] = req;
-	req->rl_niovs = 0;
-	if (req->rl_reply) {
-		buffers->rb_recv_bufs[--buffers->rb_recv_index] = req->rl_reply;
-		req->rl_reply->rr_func = NULL;
-		req->rl_reply = NULL;
-	}
+	rpcrdma_buffer_put_sendbuf(req, buffers);
 	switch (ia->ri_memreg_strategy) {
 	case RPCRDMA_FRMR:
 	case RPCRDMA_MTHCAFMR:
-		/*
-		 * Cycle mw's back in reverse order, and "spin" them.
-		 * This delays and scrambles reuse as much as possible.
-		 */
-		i = 1;
-		do {
-			struct rpcrdma_mw **mw;
-			mw = &req->rl_segments[i].mr_chunk.rl_mw;
-			list_add_tail(&(*mw)->mw_list, &buffers->rb_mws);
-			*mw = NULL;
-		} while (++i < RPCRDMA_MAX_SEGS);
-		list_add_tail(&req->rl_segments[0].mr_chunk.rl_mw->mw_list,
-					&buffers->rb_mws);
-		req->rl_segments[0].mr_chunk.rl_mw = NULL;
+		rpcrdma_buffer_put_mrs(req, buffers);
 		break;
 	default:
 		break;
@@ -1388,6 +1617,9 @@ rpcrdma_register_internal(struct rpcrdma_ia *ia, void *va, int len,
 	 */
 	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) {
@@ -1483,8 +1715,10 @@ rpcrdma_register_frmr_external(struct rpcrdma_mr_seg *seg,
 			struct rpcrdma_xprt *r_xprt)
 {
 	struct rpcrdma_mr_seg *seg1 = seg;
-	struct ib_send_wr invalidate_wr, frmr_wr, *bad_wr, *post_wr;
-
+	struct rpcrdma_mw *mw = seg1->mr_chunk.rl_mw;
+	struct rpcrdma_frmr *frmr = &mw->r.frmr;
+	struct ib_mr *mr = frmr->fr_mr;
+	struct ib_send_wr fastreg_wr, *bad_wr;
 	u8 key;
 	int len, pageoff;
 	int i, rc;
@@ -1502,8 +1736,7 @@ rpcrdma_register_frmr_external(struct rpcrdma_mr_seg *seg,
 		rpcrdma_map_one(ia, seg, writing);
 		pa = seg->mr_dma;
 		for (seg_len = seg->mr_len; seg_len > 0; seg_len -= PAGE_SIZE) {
-			seg1->mr_chunk.rl_mw->r.frmr.fr_pgl->
-				page_list[page_no++] = pa;
+			frmr->fr_pgl->page_list[page_no++] = pa;
 			pa += PAGE_SIZE;
 		}
 		len += seg->mr_len;
@@ -1515,65 +1748,51 @@ rpcrdma_register_frmr_external(struct rpcrdma_mr_seg *seg,
 			break;
 	}
 	dprintk("RPC:       %s: Using frmr %p to map %d segments\n",
-		__func__, seg1->mr_chunk.rl_mw, i);
-
-	if (unlikely(seg1->mr_chunk.rl_mw->r.frmr.state == FRMR_IS_VALID)) {
-		dprintk("RPC:       %s: frmr %x left valid, posting invalidate.\n",
-			__func__,
-			seg1->mr_chunk.rl_mw->r.frmr.fr_mr->rkey);
-		/* Invalidate before using. */
-		memset(&invalidate_wr, 0, sizeof invalidate_wr);
-		invalidate_wr.wr_id = (unsigned long)(void *)seg1->mr_chunk.rl_mw;
-		invalidate_wr.next = &frmr_wr;
-		invalidate_wr.opcode = IB_WR_LOCAL_INV;
-		invalidate_wr.send_flags = IB_SEND_SIGNALED;
-		invalidate_wr.ex.invalidate_rkey =
-			seg1->mr_chunk.rl_mw->r.frmr.fr_mr->rkey;
-		DECR_CQCOUNT(&r_xprt->rx_ep);
-		post_wr = &invalidate_wr;
-	} else
-		post_wr = &frmr_wr;
-
-	/* Prepare FRMR WR */
-	memset(&frmr_wr, 0, sizeof frmr_wr);
-	frmr_wr.wr_id = (unsigned long)(void *)seg1->mr_chunk.rl_mw;
-	frmr_wr.opcode = IB_WR_FAST_REG_MR;
-	frmr_wr.send_flags = IB_SEND_SIGNALED;
-	frmr_wr.wr.fast_reg.iova_start = seg1->mr_dma;
-	frmr_wr.wr.fast_reg.page_list = seg1->mr_chunk.rl_mw->r.frmr.fr_pgl;
-	frmr_wr.wr.fast_reg.page_list_len = page_no;
-	frmr_wr.wr.fast_reg.page_shift = PAGE_SHIFT;
-	frmr_wr.wr.fast_reg.length = page_no << PAGE_SHIFT;
-	if (frmr_wr.wr.fast_reg.length < len) {
-		while (seg1->mr_nsegs--)
-			rpcrdma_unmap_one(ia, seg++);
-		return -EIO;
+		__func__, mw, i);
+
+	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;
+	fastreg_wr.wr.fast_reg.iova_start = seg1->mr_dma;
+	fastreg_wr.wr.fast_reg.page_list = frmr->fr_pgl;
+	fastreg_wr.wr.fast_reg.page_list_len = page_no;
+	fastreg_wr.wr.fast_reg.page_shift = PAGE_SHIFT;
+	fastreg_wr.wr.fast_reg.length = page_no << PAGE_SHIFT;
+	if (fastreg_wr.wr.fast_reg.length < len) {
+		rc = -EIO;
+		goto out_err;
 	}
 
 	/* Bump the key */
-	key = (u8)(seg1->mr_chunk.rl_mw->r.frmr.fr_mr->rkey & 0x000000FF);
-	ib_update_fast_reg_key(seg1->mr_chunk.rl_mw->r.frmr.fr_mr, ++key);
+	key = (u8)(mr->rkey & 0x000000FF);
+	ib_update_fast_reg_key(mr, ++key);
 
-	frmr_wr.wr.fast_reg.access_flags = (writing ?
+	fastreg_wr.wr.fast_reg.access_flags = (writing ?
 				IB_ACCESS_REMOTE_WRITE | IB_ACCESS_LOCAL_WRITE :
 				IB_ACCESS_REMOTE_READ);
-	frmr_wr.wr.fast_reg.rkey = seg1->mr_chunk.rl_mw->r.frmr.fr_mr->rkey;
+	fastreg_wr.wr.fast_reg.rkey = mr->rkey;
 	DECR_CQCOUNT(&r_xprt->rx_ep);
 
-	rc = ib_post_send(ia->ri_id->qp, post_wr, &bad_wr);
-
+	rc = ib_post_send(ia->ri_id->qp, &fastreg_wr, &bad_wr);
 	if (rc) {
 		dprintk("RPC:       %s: failed ib_post_send for register,"
 			" status %i\n", __func__, rc);
-		while (i--)
-			rpcrdma_unmap_one(ia, --seg);
+		ib_update_fast_reg_key(mr, --key);
+		goto out_err;
 	} else {
-		seg1->mr_rkey = seg1->mr_chunk.rl_mw->r.frmr.fr_mr->rkey;
+		seg1->mr_rkey = mr->rkey;
 		seg1->mr_base = seg1->mr_dma + pageoff;
 		seg1->mr_nsegs = i;
 		seg1->mr_len = len;
 	}
 	*nsegs = i;
+	return 0;
+out_err:
+	frmr->fr_state = FRMR_IS_INVALID;
+	while (i--)
+		rpcrdma_unmap_one(ia, --seg);
 	return rc;
 }
 
@@ -1585,20 +1804,25 @@ rpcrdma_deregister_frmr_external(struct rpcrdma_mr_seg *seg,
 	struct ib_send_wr invalidate_wr, *bad_wr;
 	int rc;
 
-	while (seg1->mr_nsegs--)
-		rpcrdma_unmap_one(ia, seg++);
+	seg1->mr_chunk.rl_mw->r.frmr.fr_state = FRMR_IS_INVALID;
 
 	memset(&invalidate_wr, 0, sizeof invalidate_wr);
 	invalidate_wr.wr_id = (unsigned long)(void *)seg1->mr_chunk.rl_mw;
 	invalidate_wr.opcode = IB_WR_LOCAL_INV;
-	invalidate_wr.send_flags = IB_SEND_SIGNALED;
 	invalidate_wr.ex.invalidate_rkey = seg1->mr_chunk.rl_mw->r.frmr.fr_mr->rkey;
 	DECR_CQCOUNT(&r_xprt->rx_ep);
 
+	read_lock(&ia->ri_qplock);
+	while (seg1->mr_nsegs--)
+		rpcrdma_unmap_one(ia, seg++);
 	rc = ib_post_send(ia->ri_id->qp, &invalidate_wr, &bad_wr);
-	if (rc)
+	read_unlock(&ia->ri_qplock);
+	if (rc) {
+		/* Force rpcrdma_buffer_get() to retry */
+		seg1->mr_chunk.rl_mw->r.frmr.fr_state = FRMR_IS_STALE;
 		dprintk("RPC:       %s: failed ib_post_send for invalidate,"
 			" status %i\n", __func__, rc);
+	}
 	return rc;
 }
 
@@ -1656,8 +1880,10 @@ rpcrdma_deregister_fmr_external(struct rpcrdma_mr_seg *seg,
 
 	list_add(&seg1->mr_chunk.rl_mw->r.fmr->list, &l);
 	rc = ib_unmap_fmr(&l);
+	read_lock(&ia->ri_qplock);
 	while (seg1->mr_nsegs--)
 		rpcrdma_unmap_one(ia, seg++);
+	read_unlock(&ia->ri_qplock);
 	if (rc)
 		dprintk("RPC:       %s: failed ib_unmap_fmr,"
 			" status %i\n", __func__, rc);
@@ -1673,7 +1899,6 @@ rpcrdma_register_external(struct rpcrdma_mr_seg *seg,
 
 	switch (ia->ri_memreg_strategy) {
 
-#if RPCRDMA_PERSISTENT_REGISTRATION
 	case RPCRDMA_ALLPHYSICAL:
 		rpcrdma_map_one(ia, seg, writing);
 		seg->mr_rkey = ia->ri_bind_mem->rkey;
@@ -1681,7 +1906,6 @@ rpcrdma_register_external(struct rpcrdma_mr_seg *seg,
 		seg->mr_nsegs = 1;
 		nsegs = 1;
 		break;
-#endif
 
 	/* Registration using frmr registration */
 	case RPCRDMA_FRMR:
@@ -1711,11 +1935,11 @@ rpcrdma_deregister_external(struct rpcrdma_mr_seg *seg,
 
 	switch (ia->ri_memreg_strategy) {
 
-#if RPCRDMA_PERSISTENT_REGISTRATION
 	case RPCRDMA_ALLPHYSICAL:
+		read_lock(&ia->ri_qplock);
 		rpcrdma_unmap_one(ia, seg);
+		read_unlock(&ia->ri_qplock);
 		break;
-#endif
 
 	case RPCRDMA_FRMR:
 		rc = rpcrdma_deregister_frmr_external(seg, ia, r_xprt);
@@ -1809,3 +2033,44 @@ rpcrdma_ep_post_recv(struct rpcrdma_ia *ia,
 			rc);
 	return rc;
 }
+
+/* Physical mapping means one Read/Write list entry per-page.
+ * All list entries must fit within an inline buffer
+ *
+ * NB: The server must return a Write list for NFS READ,
+ *     which has the same constraint. Factor in the inline
+ *     rsize as well.
+ */
+static size_t
+rpcrdma_physical_max_payload(struct rpcrdma_xprt *r_xprt)
+{
+	struct rpcrdma_create_data_internal *cdata = &r_xprt->rx_data;
+	unsigned int inline_size, pages;
+
+	inline_size = min_t(unsigned int,
+			    cdata->inline_wsize, cdata->inline_rsize);
+	inline_size -= RPCRDMA_HDRLEN_MIN;
+	pages = inline_size / sizeof(struct rpcrdma_segment);
+	return pages << PAGE_SHIFT;
+}
+
+static size_t
+rpcrdma_mr_max_payload(struct rpcrdma_xprt *r_xprt)
+{
+	return RPCRDMA_MAX_DATA_SEGS << PAGE_SHIFT;
+}
+
+size_t
+rpcrdma_max_payload(struct rpcrdma_xprt *r_xprt)
+{
+	size_t result;
+
+	switch (r_xprt->rx_ia.ri_memreg_strategy) {
+	case RPCRDMA_ALLPHYSICAL:
+		result = rpcrdma_physical_max_payload(r_xprt);
+		break;
+	default:
+		result = rpcrdma_mr_max_payload(r_xprt);
+	}
+	return result;
+}
diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h
index 89e7cd4..c419498 100644
--- a/net/sunrpc/xprtrdma/xprt_rdma.h
+++ b/net/sunrpc/xprtrdma/xprt_rdma.h
@@ -59,6 +59,7 @@
  * Interface Adapter -- one per transport instance
  */
 struct rpcrdma_ia {
+	rwlock_t		ri_qplock;
 	struct rdma_cm_id 	*ri_id;
 	struct ib_pd		*ri_pd;
 	struct ib_mr		*ri_bind_mem;
@@ -98,6 +99,14 @@ struct rpcrdma_ep {
 #define INIT_CQCOUNT(ep) atomic_set(&(ep)->rep_cqcount, (ep)->rep_cqinit)
 #define DECR_CQCOUNT(ep) atomic_sub_return(1, &(ep)->rep_cqcount)
 
+enum rpcrdma_chunktype {
+	rpcrdma_noch = 0,
+	rpcrdma_readch,
+	rpcrdma_areadch,
+	rpcrdma_writech,
+	rpcrdma_replych
+};
+
 /*
  * struct rpcrdma_rep -- this structure encapsulates state required to recv
  * and complete a reply, asychronously. It needs several pieces of
@@ -137,6 +146,40 @@ struct rpcrdma_rep {
 };
 
 /*
+ * struct rpcrdma_mw - external memory region metadata
+ *
+ * An external memory region is any buffer or page that is registered
+ * on the fly (ie, not pre-registered).
+ *
+ * Each rpcrdma_buffer has a list of free MWs anchored in rb_mws. During
+ * call_allocate, rpcrdma_buffer_get() assigns one to each segment in
+ * an rpcrdma_req. Then rpcrdma_register_external() grabs these to keep
+ * track of registration metadata while each RPC is pending.
+ * rpcrdma_deregister_external() uses this metadata to unmap and
+ * release these resources when an RPC is complete.
+ */
+enum rpcrdma_frmr_state {
+	FRMR_IS_INVALID,	/* ready to be used */
+	FRMR_IS_VALID,		/* in use */
+	FRMR_IS_STALE,		/* failed completion */
+};
+
+struct rpcrdma_frmr {
+	struct ib_fast_reg_page_list	*fr_pgl;
+	struct ib_mr			*fr_mr;
+	enum rpcrdma_frmr_state		fr_state;
+};
+
+struct rpcrdma_mw {
+	union {
+		struct ib_fmr		*fmr;
+		struct rpcrdma_frmr	frmr;
+	} r;
+	struct list_head	mw_list;
+	struct list_head	mw_all;
+};
+
+/*
  * struct rpcrdma_req -- structure central to the request/reply sequence.
  *
  * N of these are associated with a transport instance, and stored in
@@ -163,17 +206,7 @@ struct rpcrdma_rep {
 struct rpcrdma_mr_seg {		/* chunk descriptors */
 	union {				/* chunk memory handles */
 		struct ib_mr	*rl_mr;		/* if registered directly */
-		struct rpcrdma_mw {		/* if registered from region */
-			union {
-				struct ib_fmr	*fmr;
-				struct {
-					struct ib_fast_reg_page_list *fr_pgl;
-					struct ib_mr *fr_mr;
-					enum { FRMR_IS_INVALID, FRMR_IS_VALID  } state;
-				} frmr;
-			} r;
-			struct list_head mw_list;
-		} *rl_mw;
+		struct rpcrdma_mw *rl_mw;	/* if registered from region */
 	} mr_chunk;
 	u64		mr_base;	/* registration result */
 	u32		mr_rkey;	/* registration result */
@@ -191,6 +224,7 @@ 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 */
+	enum rpcrdma_chunktype	rl_rtype, rl_wtype;
 	struct rpcrdma_buffer *rl_buffer; /* home base for this structure */
 	struct rpcrdma_rep	*rl_reply;/* holder for reply buffer */
 	struct rpcrdma_mr_seg rl_segments[RPCRDMA_MAX_SEGS];/* chunk segments */
@@ -214,6 +248,7 @@ struct rpcrdma_buffer {
 	atomic_t	rb_credits;	/* most recent server credits */
 	int		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;
@@ -306,7 +341,7 @@ int rpcrdma_ep_create(struct rpcrdma_ep *, struct rpcrdma_ia *,
 				struct rpcrdma_create_data_internal *);
 void rpcrdma_ep_destroy(struct rpcrdma_ep *, struct rpcrdma_ia *);
 int rpcrdma_ep_connect(struct rpcrdma_ep *, struct rpcrdma_ia *);
-int rpcrdma_ep_disconnect(struct rpcrdma_ep *, struct rpcrdma_ia *);
+void rpcrdma_ep_disconnect(struct rpcrdma_ep *, struct rpcrdma_ia *);
 
 int rpcrdma_ep_post(struct rpcrdma_ia *, struct rpcrdma_ep *,
 				struct rpcrdma_req *);
@@ -346,7 +381,9 @@ void rpcrdma_reply_handler(struct rpcrdma_rep *);
 /*
  * RPC/RDMA protocol calls - xprtrdma/rpc_rdma.c
  */
+ssize_t rpcrdma_marshal_chunks(struct rpc_rqst *, ssize_t);
 int rpcrdma_marshal_req(struct rpc_rqst *);
+size_t rpcrdma_max_payload(struct rpcrdma_xprt *);
 
 /* Temporary NFS request map cache. Created in svc_rdma.c  */
 extern struct kmem_cache *svc_rdma_map_cachep;
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index be8bbd5..43cd89e 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -594,6 +594,7 @@ static int xs_local_send_request(struct rpc_task *task)
 	}
 
 	switch (status) {
+	case -ENOBUFS:
 	case -EAGAIN:
 		status = xs_nospace(task);
 		break;
@@ -661,6 +662,7 @@ static int xs_udp_send_request(struct rpc_task *task)
 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
 			-status);
 	case -ENETUNREACH:
+	case -ENOBUFS:
 	case -EPIPE:
 	case -ECONNREFUSED:
 		/* When the server has died, an ICMP port unreachable message
@@ -758,6 +760,7 @@ static int xs_tcp_send_request(struct rpc_task *task)
 		status = -ENOTCONN;
 		/* Should we call xs_close() here? */
 		break;
+	case -ENOBUFS:
 	case -EAGAIN:
 		status = xs_nospace(task);
 		break;
@@ -1946,6 +1949,7 @@ static int xs_local_setup_socket(struct sock_xprt *transport)
 		dprintk("RPC:       xprt %p connected to %s\n",
 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
 		xprt_set_connected(xprt);
+	case -ENOBUFS:
 		break;
 	case -ENOENT:
 		dprintk("RPC:       xprt %p: socket %s does not exist\n",
@@ -2281,6 +2285,7 @@ static void xs_tcp_setup_socket(struct work_struct *work)
 	case -ECONNREFUSED:
 	case -ECONNRESET:
 	case -ENETUNREACH:
+	case -ENOBUFS:
 		/* retry with existing socket, after a delay */
 		goto out;
 	}
@@ -3054,12 +3059,12 @@ static int param_set_uint_minmax(const char *val,
 		const struct kernel_param *kp,
 		unsigned int min, unsigned int max)
 {
-	unsigned long num;
+	unsigned int num;
 	int ret;
 
 	if (!val)
 		return -EINVAL;
-	ret = strict_strtoul(val, 0, &num);
+	ret = kstrtouint(val, 0, &num);
 	if (ret == -EINVAL || num < min || num > max)
 		return -EINVAL;
 	*((unsigned int *)kp->arg) = num;