[RFC PATCH 0/3] RDMA/smbdirect: introduce and use rdma_restrict_node_type()

[RFC PATCH 0/3] RDMA/smbdirect: introduce and use rdma_restrict_node_type()

[Stefan Metzmacher]

Hi,

for smbdirect it required to use different ports depending
on the RDMA protocol. E.g. for iWarp 5445 is needed
(as tcp port 445 already used by the raw tcp transport for SMB),
while InfiniBand, RoCEv1 and RoCEv2 use port 445, as they
use an independent port range (even for RoCEv2, which uses udp
port 4791 itself).

Currently ksmbd is not able to function correctly at
all if the system has iWarp (RDMA_NODE_RNIC) interface(s)
and any InfiniBand, RoCEv1 and/or RoCEv2 interface(s)
at the same time.

And cifs.ko uses 5445 with a fallback to 445, which
means depending on the available interfaces, it tries
5445 in the RoCE range or may tries iWarp with 445
as a fallback. This leads to strange error messages
and strange network captures.

To avoid these problems they will be able to
use rdma_restrict_node_type(RDMA_NODE_RNIC) before
trying port 5445 and rdma_restrict_node_type(RDMA_NODE_IB_CA)
before trying port 445. It means we'll get early
-ENODEV early from rdma_resolve_addr() without any
network traffic and timeouts.

This is marked as RFC as I want to get feedback
if the rdma_restrict_node_type() function is acceptable
for the RDMA layer. And because the current form of
the smb patches are not tested, I only tested the
rdma part with my branch the prepares IPPROTO_SMBDIRECT
sockets.

I'm not sure if this would be acceptable for 6.19
in order to avoid the smb layer problems, if the
RDMA layer change is only acceptable for 7.0 that's
also fine.

This is based on the following fix applied:
smb: server: reset smb_direct_port = SMB_DIRECT_PORT_INFINIBAND on init
https://lore.kernel.org/linux-cifs/20251208154919.934760-1-metze@samba.org/
It's not yet in Linus' tree, so if this gets ready
before it's merged we can squash it.

Stefan Metzmacher (3):
  RDMA/core: introduce rdma_restrict_node_type()
  smb: client: make use of rdma_restrict_node_type()
  smb: server: make use of rdma_restrict_node_type()

 drivers/infiniband/core/cma.c      |  30 ++++++++
 drivers/infiniband/core/cma_priv.h |   1 +
 fs/smb/client/smbdirect.c          |  26 +++++++
 fs/smb/server/transport_rdma.c     | 108 +++++++++++++++++++++--------
 include/rdma/rdma_cm.h             |  17 +++++
 5 files changed, 154 insertions(+), 28 deletions(-)

-- 
2.43.0

[RFC PATCH 1/3] RDMA/core: introduce rdma_restrict_node_type()

[Stefan Metzmacher]

For smbdirect it required to use different ports depending
on the RDMA protocol. E.g. for iWarp 5445 is needed
(as tcp port 445 already used by the raw tcp transport for SMB),
while InfiniBand, RoCEv1 and RoCEv2 use port 445, as they
use an independent port range (even for RoCEv2, which uses udp
port 4791 itself).

Currently ksmbd is not able to function correctly at
all if the system has iWarp (RDMA_NODE_RNIC) interface(s)
and any InfiniBand, RoCEv1 and/or RoCEv2 interface(s)
at the same time.

And cifs.ko uses 5445 with a fallback to 445, which
means depending on the available interfaces, it tries
5445 in the RoCE range or may tries iWarp with 445
as a fallback. This leads to strange error messages
and strange network captures.

To avoid these problems they will be able to
use rdma_restrict_node_type(RDMA_NODE_RNIC) before
trying port 5445 and rdma_restrict_node_type(RDMA_NODE_IB_CA)
before trying port 445. It means we'll get early
-ENODEV early from rdma_resolve_addr() without any
network traffic and timeouts.

This is designed to be called before calling any
of rdma_bind_addr(), rdma_resolve_addr() or rdma_listen().

Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Long Li <longli@microsoft.com>
Cc: Namjae Jeon <linkinjeon@kernel.org>
Cc: linux-rdma@vger.kernel.org
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Signed-off-by: Stefan Metzmacher <metze@samba.org>
---
 drivers/infiniband/core/cma.c      | 30 ++++++++++++++++++++++++++++++
 drivers/infiniband/core/cma_priv.h |  1 +
 include/rdma/rdma_cm.h             | 17 +++++++++++++++++
 3 files changed, 48 insertions(+)

diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index f00f1d3fbd9c..0ee855a71ed4 100644
--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -793,6 +793,9 @@ static int cma_acquire_dev_by_src_ip(struct rdma_id_private *id_priv)
 
 	mutex_lock(&lock);
 	list_for_each_entry(cma_dev, &dev_list, list) {
+		if (id_priv->restricted_node_type != RDMA_NODE_UNSPECIFIED &&
+		    id_priv->restricted_node_type != cma_dev->device->node_type)
+			continue;
 		rdma_for_each_port (cma_dev->device, port) {
 			gidp = rdma_protocol_roce(cma_dev->device, port) ?
 			       &iboe_gid : &gid;
@@ -1015,6 +1018,7 @@ __rdma_create_id(struct net *net, rdma_cm_event_handler event_handler,
 		return ERR_PTR(-ENOMEM);
 
 	id_priv->state = RDMA_CM_IDLE;
+	id_priv->restricted_node_type = RDMA_NODE_UNSPECIFIED;
 	id_priv->id.context = context;
 	id_priv->id.event_handler = event_handler;
 	id_priv->id.ps = ps;
@@ -4177,6 +4181,32 @@ int rdma_resolve_addr(struct rdma_cm_id *id, struct sockaddr *src_addr,
 }
 EXPORT_SYMBOL(rdma_resolve_addr);
 
+int rdma_restrict_node_type(struct rdma_cm_id *id, u8 node_type)
+{
+	struct rdma_id_private *id_priv =
+		container_of(id, struct rdma_id_private, id);
+	int ret = 0;
+
+	switch (node_type) {
+	case RDMA_NODE_UNSPECIFIED:
+	case RDMA_NODE_IB_CA:
+	case RDMA_NODE_RNIC:
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	mutex_lock(&lock);
+	if (id_priv->cma_dev)
+		ret = -EALREADY;
+	else
+		id_priv->restricted_node_type = node_type;
+	mutex_unlock(&lock);
+
+	return ret;
+}
+EXPORT_SYMBOL(rdma_restrict_node_type);
+
 int rdma_bind_addr(struct rdma_cm_id *id, struct sockaddr *addr)
 {
 	struct rdma_id_private *id_priv =
diff --git a/drivers/infiniband/core/cma_priv.h b/drivers/infiniband/core/cma_priv.h
index c604b601f4d9..04332eb82668 100644
--- a/drivers/infiniband/core/cma_priv.h
+++ b/drivers/infiniband/core/cma_priv.h
@@ -72,6 +72,7 @@ struct rdma_id_private {
 
 	int			internal_id;
 	enum rdma_cm_state	state;
+	u8			restricted_node_type;
 	spinlock_t		lock;
 	struct mutex		qp_mutex;
 
diff --git a/include/rdma/rdma_cm.h b/include/rdma/rdma_cm.h
index 9bd930a83e6e..6de6fd8bd15e 100644
--- a/include/rdma/rdma_cm.h
+++ b/include/rdma/rdma_cm.h
@@ -168,6 +168,23 @@ struct rdma_cm_id *rdma_create_user_id(rdma_cm_event_handler event_handler,
   */
 void rdma_destroy_id(struct rdma_cm_id *id);
 
+/**
+ * rdma_restrict_node_type - Restrict an RDMA identifier to specific
+ *   RDMA device node type.
+ *
+ * @id: RDMA identifier.
+ * @node_type: The device node type. Only RDMA_NODE_UNSPECIFIED (default),
+ *   RDMA_NODE_RNIC and RDMA_NODE_IB_CA are allowed
+ *
+ * This allows the caller to restrict the possible devices
+ * used to iWarp (RDMA_NODE_RNIC) or InfiniBand/RoCEv1/RoCEv2 (RDMA_NODE_IB_CA).
+ *
+ * It needs to be called before the RDMA identifier is bound
+ * to an device, which mean it should be called before
+ * rdma_bind_addr(), rdma_bind_addr() and rdma_listen().
+ */
+int rdma_restrict_node_type(struct rdma_cm_id *id, u8 node_type);
+
 /**
  * rdma_bind_addr - Bind an RDMA identifier to a source address and
  *   associated RDMA device, if needed.
-- 
2.43.0

Re: [RFC PATCH 1/3] RDMA/core: introduce rdma_restrict_node_type()

[Leon Romanovsky]

On Wed, Jan 21, 2026 at 09:07:11PM +0100, Stefan Metzmacher wrote:
> For smbdirect it required to use different ports depending
> on the RDMA protocol. E.g. for iWarp 5445 is needed
> (as tcp port 445 already used by the raw tcp transport for SMB),
> while InfiniBand, RoCEv1 and RoCEv2 use port 445, as they
> use an independent port range (even for RoCEv2, which uses udp
> port 4791 itself).
> 
> Currently ksmbd is not able to function correctly at
> all if the system has iWarp (RDMA_NODE_RNIC) interface(s)
> and any InfiniBand, RoCEv1 and/or RoCEv2 interface(s)
> at the same time.
> 
> And cifs.ko uses 5445 with a fallback to 445, which
> means depending on the available interfaces, it tries
> 5445 in the RoCE range or may tries iWarp with 445
> as a fallback. This leads to strange error messages
> and strange network captures.
> 
> To avoid these problems they will be able to
> use rdma_restrict_node_type(RDMA_NODE_RNIC) before
> trying port 5445 and rdma_restrict_node_type(RDMA_NODE_IB_CA)
> before trying port 445. It means we'll get early
> -ENODEV early from rdma_resolve_addr() without any
> network traffic and timeouts.
> 
> This is designed to be called before calling any
> of rdma_bind_addr(), rdma_resolve_addr() or rdma_listen().
> 
> Cc: Jason Gunthorpe <jgg@ziepe.ca>
> Cc: Leon Romanovsky <leon@kernel.org>
> Cc: Steve French <smfrench@gmail.com>
> Cc: Tom Talpey <tom@talpey.com>
> Cc: Long Li <longli@microsoft.com>
> Cc: Namjae Jeon <linkinjeon@kernel.org>
> Cc: linux-rdma@vger.kernel.org
> Cc: linux-cifs@vger.kernel.org
> Cc: samba-technical@lists.samba.org
> Signed-off-by: Stefan Metzmacher <metze@samba.org>
> ---
>  drivers/infiniband/core/cma.c      | 30 ++++++++++++++++++++++++++++++
>  drivers/infiniband/core/cma_priv.h |  1 +
>  include/rdma/rdma_cm.h             | 17 +++++++++++++++++
>  3 files changed, 48 insertions(+)

Thanks,
Acked-by: Leon Romanovsky <leon@kernel.org>

[RFC PATCH 2/3] smb: client: make use of rdma_restrict_node_type()

[Stefan Metzmacher]

For smbdirect it required to use different ports depending
on the RDMA protocol. E.g. for iWarp 5445 is needed
(as tcp port 445 already used by the raw tcp transport for SMB),
while InfiniBand, RoCEv1 and RoCEv2 use port 445, as they
use an independent port range (even for RoCEv2, which uses udp
port 4791 itself).

And cifs.ko uses 5445 with a fallback to 445, which
means depending on the available interfaces, it tries
5445 in the RoCE range or may tries iWarp with 445
as a fallback. This leads to strange error messages
and strange network captures.

To avoid these problems they will be able to
use rdma_restrict_node_type(RDMA_NODE_RNIC) before
trying port 5445 and rdma_restrict_node_type(RDMA_NODE_IB_CA)
before trying port 445. It means we'll get early
-ENODEV early from rdma_resolve_addr() without any
network traffic and timeouts.

Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Long Li <longli@microsoft.com>
Cc: Namjae Jeon <linkinjeon@kernel.org>
Cc: linux-rdma@vger.kernel.org
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Signed-off-by: Stefan Metzmacher <metze@samba.org>
---
 fs/smb/client/smbdirect.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/fs/smb/client/smbdirect.c b/fs/smb/client/smbdirect.c
index 2900b02f90cd..e69bce88cc9c 100644
--- a/fs/smb/client/smbdirect.c
+++ b/fs/smb/client/smbdirect.c
@@ -903,6 +903,7 @@ static struct rdma_cm_id *smbd_create_id(
 {
 	struct smbdirect_socket_parameters *sp = &sc->parameters;
 	struct rdma_cm_id *id;
+	u8 node_type = RDMA_NODE_UNSPECIFIED;
 	int rc;
 	__be16 *sport;
 
@@ -914,6 +915,31 @@ static struct rdma_cm_id *smbd_create_id(
 		return id;
 	}
 
+	switch (port) {
+	case SMBD_PORT:
+		/*
+		 * only allow iWarp devices
+		 * for port 5445.
+		 */
+		node_type = RDMA_NODE_RNIC;
+		break;
+	case SMB_PORT:
+		/*
+		 * only allow InfiniBand, RoCEv1 or RoCEv2
+		 * devices for port 445.
+		 *
+		 * (Basically don't allow iWarp devices)
+		 */
+		node_type = RDMA_NODE_IB_CA;
+		break;
+	}
+	rc = rdma_restrict_node_type(id, node_type);
+	if (rc) {
+		log_rdma_event(ERR, "rdma_restrict_node_type(%u) failed %i\n",
+			       node_type, rc);
+		goto out;
+	}
+
 	if (dstaddr->sa_family == AF_INET6)
 		sport = &((struct sockaddr_in6 *)dstaddr)->sin6_port;
 	else
-- 
2.43.0

[RFC PATCH 3/3] smb: server: make use of rdma_restrict_node_type()

[Stefan Metzmacher]

For smbdirect it required to use different ports depending
on the RDMA protocol. E.g. for iWarp 5445 is needed
(as tcp port 445 already used by the raw tcp transport for SMB),
while InfiniBand, RoCEv1 and RoCEv2 use port 445, as they
use an independent port range (even for RoCEv2, which uses udp
port 4791 itself).

Currently ksmbd is not able to function correctly at
all if the system has iWarp (RDMA_NODE_RNIC) interface(s)
and any InfiniBand, RoCEv1 and/or RoCEv2 interface(s)
at the same time.

Now we do a wildcard listen on port 5445 only
for iWarp devices and another wildcard listen
on port 445 of any InfiniBand, RoCEv1 and/or RoCEv2
devices.

The wildcard listeners also work if there is
no device of the requested node_type, this
is the same logic as we had before, but before
we had to decide between port 5445 or 445
and now both are possible at the same time.

Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Long Li <longli@microsoft.com>
Cc: Namjae Jeon <linkinjeon@kernel.org>
Cc: linux-rdma@vger.kernel.org
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Signed-off-by: Stefan Metzmacher <metze@samba.org>
---
 fs/smb/server/transport_rdma.c | 108 ++++++++++++++++++++++++---------
 1 file changed, 80 insertions(+), 28 deletions(-)

diff --git a/fs/smb/server/transport_rdma.c b/fs/smb/server/transport_rdma.c
index 541e51a7c0ce..675194a24e36 100644
--- a/fs/smb/server/transport_rdma.c
+++ b/fs/smb/server/transport_rdma.c
@@ -61,9 +61,6 @@
  * Those may change after a SMB_DIRECT negotiation
  */
 
-/* Set 445 port to SMB Direct port by default */
-static int smb_direct_port = SMB_DIRECT_PORT_INFINIBAND;
-
 /* The local peer's maximum number of credits to grant to the peer */
 static int smb_direct_receive_credit_max = 255;
 
@@ -90,8 +87,9 @@ struct smb_direct_device {
 };
 
 static struct smb_direct_listener {
+	int			port;
 	struct rdma_cm_id	*cm_id;
-} smb_direct_listener;
+} smb_direct_ib_listener, smb_direct_iw_listener;
 
 static struct workqueue_struct *smb_direct_wq;
 
@@ -2621,6 +2619,7 @@ static bool rdma_frwr_is_supported(struct ib_device_attr *attrs)
 static int smb_direct_handle_connect_request(struct rdma_cm_id *new_cm_id,
 					     struct rdma_cm_event *event)
 {
+	struct smb_direct_listener *listener = new_cm_id->context;
 	struct smb_direct_transport *t;
 	struct smbdirect_socket *sc;
 	struct smbdirect_socket_parameters *sp;
@@ -2709,7 +2708,7 @@ static int smb_direct_handle_connect_request(struct rdma_cm_id *new_cm_id,
 
 	handler = kthread_run(ksmbd_conn_handler_loop,
 			      KSMBD_TRANS(t)->conn, "ksmbd:r%u",
-			      smb_direct_port);
+			      listener->port);
 	if (IS_ERR(handler)) {
 		ret = PTR_ERR(handler);
 		pr_err("Can't start thread\n");
@@ -2746,39 +2745,73 @@ static int smb_direct_listen_handler(struct rdma_cm_id *cm_id,
 	return 0;
 }
 
-static int smb_direct_listen(int port)
+static int smb_direct_listen(struct smb_direct_listener *listener,
+			     int port)
 {
 	int ret;
 	struct rdma_cm_id *cm_id;
+	u8 node_type = RDMA_NODE_UNSPECIFIED;
 	struct sockaddr_in sin = {
 		.sin_family		= AF_INET,
 		.sin_addr.s_addr	= htonl(INADDR_ANY),
 		.sin_port		= htons(port),
 	};
 
+	switch (port) {
+	case SMB_DIRECT_PORT_IWARP:
+		/*
+		 * only allow iWarp devices
+		 * for port 5445.
+		 */
+		node_type = RDMA_NODE_RNIC;
+		break;
+	case SMB_DIRECT_PORT_INFINIBAND:
+		/*
+		 * only allow InfiniBand, RoCEv1 or RoCEv2
+		 * devices for port 445.
+		 *
+		 * (Basically don't allow iWarp devices)
+		 */
+		node_type = RDMA_NODE_IB_CA;
+		break;
+	default:
+		pr_err("unsupported smbdirect port=%d!\n", port);
+		return -ENODEV;
+	}
+
 	cm_id = rdma_create_id(&init_net, smb_direct_listen_handler,
-			       &smb_direct_listener, RDMA_PS_TCP, IB_QPT_RC);
+			       listener, RDMA_PS_TCP, IB_QPT_RC);
 	if (IS_ERR(cm_id)) {
 		pr_err("Can't create cm id: %ld\n", PTR_ERR(cm_id));
 		return PTR_ERR(cm_id);
 	}
 
+	ret = rdma_restrict_node_type(cm_id, node_type);
+	if (ret) {
+		pr_err("rdma_restrict_node_type(%u) failed %d\n",
+		       node_type, ret);
+		goto err;
+	}
+
 	ret = rdma_bind_addr(cm_id, (struct sockaddr *)&sin);
 	if (ret) {
 		pr_err("Can't bind: %d\n", ret);
 		goto err;
 	}
 
-	smb_direct_listener.cm_id = cm_id;
-
 	ret = rdma_listen(cm_id, 10);
 	if (ret) {
 		pr_err("Can't listen: %d\n", ret);
 		goto err;
 	}
+
+	listener->port = port;
+	listener->cm_id = cm_id;
+
 	return 0;
 err:
-	smb_direct_listener.cm_id = NULL;
+	listener->port = 0;
+	listener->cm_id = NULL;
 	rdma_destroy_id(cm_id);
 	return ret;
 }
@@ -2787,10 +2820,6 @@ static int smb_direct_ib_client_add(struct ib_device *ib_dev)
 {
 	struct smb_direct_device *smb_dev;
 
-	/* Set 5445 port if device type is iWARP(No IB) */
-	if (ib_dev->node_type != RDMA_NODE_IB_CA)
-		smb_direct_port = SMB_DIRECT_PORT_IWARP;
-
 	if (!rdma_frwr_is_supported(&ib_dev->attrs))
 		return 0;
 
@@ -2833,8 +2862,9 @@ int ksmbd_rdma_init(void)
 {
 	int ret;
 
-	smb_direct_port = SMB_DIRECT_PORT_INFINIBAND;
-	smb_direct_listener.cm_id = NULL;
+	smb_direct_ib_listener = smb_direct_iw_listener = (struct smb_direct_listener) {
+		.cm_id = NULL,
+	};
 
 	ret = ib_register_client(&smb_direct_ib_client);
 	if (ret) {
@@ -2850,31 +2880,53 @@ int ksmbd_rdma_init(void)
 	smb_direct_wq = alloc_workqueue("ksmbd-smb_direct-wq",
 					WQ_HIGHPRI | WQ_MEM_RECLAIM | WQ_PERCPU,
 					0);
-	if (!smb_direct_wq)
-		return -ENOMEM;
+	if (!smb_direct_wq) {
+		ret = -ENOMEM;
+		goto err;
+	}
 
-	ret = smb_direct_listen(smb_direct_port);
+	ret = smb_direct_listen(&smb_direct_ib_listener,
+				SMB_DIRECT_PORT_INFINIBAND);
 	if (ret) {
-		destroy_workqueue(smb_direct_wq);
-		smb_direct_wq = NULL;
-		pr_err("Can't listen: %d\n", ret);
-		return ret;
+		pr_err("Can't listen on InfiniBand/RoCEv1/RoCEv2: %d\n", ret);
+		goto err;
 	}
 
-	ksmbd_debug(RDMA, "init RDMA listener. cm_id=%p\n",
-		    smb_direct_listener.cm_id);
+	ksmbd_debug(RDMA, "InfiniBand/RoCEv1/RoCEv2 RDMA listener. cm_id=%p\n",
+		    smb_direct_ib_listener.cm_id);
+
+	ret = smb_direct_listen(&smb_direct_iw_listener,
+				SMB_DIRECT_PORT_IWARP);
+	if (ret) {
+		pr_err("Can't listen on iWarp: %d\n", ret);
+		goto err;
+	}
+
+	ksmbd_debug(RDMA, "iWarp RDMA listener. cm_id=%p\n",
+		    smb_direct_iw_listener.cm_id);
+
 	return 0;
+err:
+	ksmbd_rdma_stop_listening();
+	ksmbd_rdma_destroy();
+	return ret;
 }
 
 void ksmbd_rdma_stop_listening(void)
 {
-	if (!smb_direct_listener.cm_id)
+	if (!smb_direct_ib_listener.cm_id && !smb_direct_iw_listener.cm_id)
 		return;
 
 	ib_unregister_client(&smb_direct_ib_client);
-	rdma_destroy_id(smb_direct_listener.cm_id);
 
-	smb_direct_listener.cm_id = NULL;
+	if (smb_direct_ib_listener.cm_id)
+		rdma_destroy_id(smb_direct_ib_listener.cm_id);
+	if (smb_direct_iw_listener.cm_id)
+		rdma_destroy_id(smb_direct_iw_listener.cm_id);
+
+	smb_direct_ib_listener = smb_direct_iw_listener = (struct smb_direct_listener) {
+		.cm_id = NULL,
+	};
 }
 
 void ksmbd_rdma_destroy(void)
-- 
2.43.0

Re: [RFC PATCH 0/3] RDMA/smbdirect: introduce and use rdma_restrict_node_type()

[Leon Romanovsky]

On Wed, Jan 21, 2026 at 09:07:10PM +0100, Stefan Metzmacher wrote:
> Hi,
> 
> for smbdirect it required to use different ports depending
> on the RDMA protocol. E.g. for iWarp 5445 is needed
> (as tcp port 445 already used by the raw tcp transport for SMB),
> while InfiniBand, RoCEv1 and RoCEv2 use port 445, as they
> use an independent port range (even for RoCEv2, which uses udp
> port 4791 itself).
> 
> Currently ksmbd is not able to function correctly at
> all if the system has iWarp (RDMA_NODE_RNIC) interface(s)
> and any InfiniBand, RoCEv1 and/or RoCEv2 interface(s)
> at the same time.
> 
> And cifs.ko uses 5445 with a fallback to 445, which
> means depending on the available interfaces, it tries
> 5445 in the RoCE range or may tries iWarp with 445
> as a fallback. This leads to strange error messages
> and strange network captures.
> 
> To avoid these problems they will be able to
> use rdma_restrict_node_type(RDMA_NODE_RNIC) before
> trying port 5445 and rdma_restrict_node_type(RDMA_NODE_IB_CA)
> before trying port 445. It means we'll get early
> -ENODEV early from rdma_resolve_addr() without any
> network traffic and timeouts.
> 
> This is marked as RFC as I want to get feedback
> if the rdma_restrict_node_type() function is acceptable
> for the RDMA layer. And because the current form of
> the smb patches are not tested, I only tested the
> rdma part with my branch the prepares IPPROTO_SMBDIRECT
> sockets.
> 
> I'm not sure if this would be acceptable for 6.19
> in order to avoid the smb layer problems, if the
> RDMA layer change is only acceptable for 7.0 that's
> also fine.
> 
> This is based on the following fix applied:
> smb: server: reset smb_direct_port = SMB_DIRECT_PORT_INFINIBAND on init
> https://lore.kernel.org/linux-cifs/20251208154919.934760-1-metze@samba.org/
> It's not yet in Linus' tree, so if this gets ready
> before it's merged we can squash it.
> 
> Stefan Metzmacher (3):
>   RDMA/core: introduce rdma_restrict_node_type()
>   smb: client: make use of rdma_restrict_node_type()
>   smb: server: make use of rdma_restrict_node_type()

The approach looks reasonable. Do you want me to take it through RDMA
tree?

Thanks

> 
>  drivers/infiniband/core/cma.c      |  30 ++++++++
>  drivers/infiniband/core/cma_priv.h |   1 +
>  fs/smb/client/smbdirect.c          |  26 +++++++
>  fs/smb/server/transport_rdma.c     | 108 +++++++++++++++++++++--------
>  include/rdma/rdma_cm.h             |  17 +++++
>  5 files changed, 154 insertions(+), 28 deletions(-)
> 
> -- 
> 2.43.0
> 

Re: [RFC PATCH 0/3] RDMA/smbdirect: introduce and use rdma_restrict_node_type()

[Stefan Metzmacher]

Am 28.01.26 um 15:11 schrieb Leon Romanovsky:
> On Wed, Jan 21, 2026 at 09:07:10PM +0100, Stefan Metzmacher wrote:
>> Hi,
>>
>> for smbdirect it required to use different ports depending
>> on the RDMA protocol. E.g. for iWarp 5445 is needed
>> (as tcp port 445 already used by the raw tcp transport for SMB),
>> while InfiniBand, RoCEv1 and RoCEv2 use port 445, as they
>> use an independent port range (even for RoCEv2, which uses udp
>> port 4791 itself).
>>
>> Currently ksmbd is not able to function correctly at
>> all if the system has iWarp (RDMA_NODE_RNIC) interface(s)
>> and any InfiniBand, RoCEv1 and/or RoCEv2 interface(s)
>> at the same time.
>>
>> And cifs.ko uses 5445 with a fallback to 445, which
>> means depending on the available interfaces, it tries
>> 5445 in the RoCE range or may tries iWarp with 445
>> as a fallback. This leads to strange error messages
>> and strange network captures.
>>
>> To avoid these problems they will be able to
>> use rdma_restrict_node_type(RDMA_NODE_RNIC) before
>> trying port 5445 and rdma_restrict_node_type(RDMA_NODE_IB_CA)
>> before trying port 445. It means we'll get early
>> -ENODEV early from rdma_resolve_addr() without any
>> network traffic and timeouts.
>>
>> This is marked as RFC as I want to get feedback
>> if the rdma_restrict_node_type() function is acceptable
>> for the RDMA layer. And because the current form of
>> the smb patches are not tested, I only tested the
>> rdma part with my branch the prepares IPPROTO_SMBDIRECT
>> sockets.
>>
>> I'm not sure if this would be acceptable for 6.19
>> in order to avoid the smb layer problems, if the
>> RDMA layer change is only acceptable for 7.0 that's
>> also fine.
>>
>> This is based on the following fix applied:
>> smb: server: reset smb_direct_port = SMB_DIRECT_PORT_INFINIBAND on init
>> https://lore.kernel.org/linux-cifs/20251208154919.934760-1-metze@samba.org/
>> It's not yet in Linus' tree, so if this gets ready
>> before it's merged we can squash it.
>>
>> Stefan Metzmacher (3):
>>    RDMA/core: introduce rdma_restrict_node_type()
>>    smb: client: make use of rdma_restrict_node_type()
>>    smb: server: make use of rdma_restrict_node_type()
>
> The approach looks reasonable.

Thanks!

> Do you want me to take it through RDMA
> tree?

As I also have other smb patches on top changing/using
it I guess it would be easier if Steve would take them.

Steve, Leon what do you think?

Thanks!
metze

Re: [RFC PATCH 0/3] RDMA/smbdirect: introduce and use rdma_restrict_node_type()

[Leon Romanovsky]

On Tue, Feb 03, 2026 at 04:25:35PM +0100, Stefan Metzmacher wrote:
> Am 28.01.26 um 15:11 schrieb Leon Romanovsky:
> > On Wed, Jan 21, 2026 at 09:07:10PM +0100, Stefan Metzmacher wrote:
> > > Hi,
> > > 
> > > for smbdirect it required to use different ports depending
> > > on the RDMA protocol. E.g. for iWarp 5445 is needed
> > > (as tcp port 445 already used by the raw tcp transport for SMB),
> > > while InfiniBand, RoCEv1 and RoCEv2 use port 445, as they
> > > use an independent port range (even for RoCEv2, which uses udp
> > > port 4791 itself).
> > > 
> > > Currently ksmbd is not able to function correctly at
> > > all if the system has iWarp (RDMA_NODE_RNIC) interface(s)
> > > and any InfiniBand, RoCEv1 and/or RoCEv2 interface(s)
> > > at the same time.
> > > 
> > > And cifs.ko uses 5445 with a fallback to 445, which
> > > means depending on the available interfaces, it tries
> > > 5445 in the RoCE range or may tries iWarp with 445
> > > as a fallback. This leads to strange error messages
> > > and strange network captures.
> > > 
> > > To avoid these problems they will be able to
> > > use rdma_restrict_node_type(RDMA_NODE_RNIC) before
> > > trying port 5445 and rdma_restrict_node_type(RDMA_NODE_IB_CA)
> > > before trying port 445. It means we'll get early
> > > -ENODEV early from rdma_resolve_addr() without any
> > > network traffic and timeouts.
> > > 
> > > This is marked as RFC as I want to get feedback
> > > if the rdma_restrict_node_type() function is acceptable
> > > for the RDMA layer. And because the current form of
> > > the smb patches are not tested, I only tested the
> > > rdma part with my branch the prepares IPPROTO_SMBDIRECT
> > > sockets.
> > > 
> > > I'm not sure if this would be acceptable for 6.19
> > > in order to avoid the smb layer problems, if the
> > > RDMA layer change is only acceptable for 7.0 that's
> > > also fine.
> > > 
> > > This is based on the following fix applied:
> > > smb: server: reset smb_direct_port = SMB_DIRECT_PORT_INFINIBAND on init
> > > https://lore.kernel.org/linux-cifs/20251208154919.934760-1-metze@samba.org/
> > > It's not yet in Linus' tree, so if this gets ready
> > > before it's merged we can squash it.
> > > 
> > > Stefan Metzmacher (3):
> > >    RDMA/core: introduce rdma_restrict_node_type()
> > >    smb: client: make use of rdma_restrict_node_type()
> > >    smb: server: make use of rdma_restrict_node_type()
> > 
> > The approach looks reasonable.
> 
> Thanks!
> 
> > Do you want me to take it through RDMA
> > tree?
> 
> As I also have other smb patches on top changing/using
> it I guess it would be easier if Steve would take them.
> 
> Steve, Leon what do you think?

I'm ok with that, let's me add my Acked-by on first patch.

Thanks

> 
> Thanks!
> metze

Re: [RFC PATCH 0/3] RDMA/smbdirect: introduce and use rdma_restrict_node_type()

[Steve French]

On Tue, Feb 3, 2026 at 9:25 AM Stefan Metzmacher <metze@samba.org> wrote:
>
> Am 28.01.26 um 15:11 schrieb Leon Romanovsky:
> > On Wed, Jan 21, 2026 at 09:07:10PM +0100, Stefan Metzmacher wrote:
> >> Hi,
> >>
> >> for smbdirect it required to use different ports depending
> >> on the RDMA protocol. E.g. for iWarp 5445 is needed
> >> (as tcp port 445 already used by the raw tcp transport for SMB),
> >> while InfiniBand, RoCEv1 and RoCEv2 use port 445, as they
> >> use an independent port range (even for RoCEv2, which uses udp
> >> port 4791 itself).
> >>
> >> Currently ksmbd is not able to function correctly at
> >> all if the system has iWarp (RDMA_NODE_RNIC) interface(s)
> >> and any InfiniBand, RoCEv1 and/or RoCEv2 interface(s)
> >> at the same time.
> >>
> >> And cifs.ko uses 5445 with a fallback to 445, which
> >> means depending on the available interfaces, it tries
> >> 5445 in the RoCE range or may tries iWarp with 445
> >> as a fallback. This leads to strange error messages
> >> and strange network captures.
> >>
> >> To avoid these problems they will be able to
> >> use rdma_restrict_node_type(RDMA_NODE_RNIC) before
> >> trying port 5445 and rdma_restrict_node_type(RDMA_NODE_IB_CA)
> >> before trying port 445. It means we'll get early
> >> -ENODEV early from rdma_resolve_addr() without any
> >> network traffic and timeouts.
> >>
> >> This is marked as RFC as I want to get feedback
> >> if the rdma_restrict_node_type() function is acceptable
> >> for the RDMA layer. And because the current form of
> >> the smb patches are not tested, I only tested the
> >> rdma part with my branch the prepares IPPROTO_SMBDIRECT
> >> sockets.
> >>
> >> I'm not sure if this would be acceptable for 6.19
> >> in order to avoid the smb layer problems, if the
> >> RDMA layer change is only acceptable for 7.0 that's
> >> also fine.
> >>
> >> This is based on the following fix applied:
> >> smb: server: reset smb_direct_port = SMB_DIRECT_PORT_INFINIBAND on init
> >> https://lore.kernel.org/linux-cifs/20251208154919.934760-1-metze@samba.org/
> >> It's not yet in Linus' tree, so if this gets ready
> >> before it's merged we can squash it.
> >>
> >> Stefan Metzmacher (3):
> >>    RDMA/core: introduce rdma_restrict_node_type()
> >>    smb: client: make use of rdma_restrict_node_type()
> >>    smb: server: make use of rdma_restrict_node_type()
> >
> > The approach looks reasonable.
>
> Thanks!
>
> > Do you want me to take it through RDMA
> > tree?
>
> As I also have other smb patches on top changing/using
> it I guess it would be easier if Steve would take them.
>
> Steve, Leon what do you think?

I am ok with taking it via the ksmbd tree (smb3-kernel ksmbd-for-next
branch), unless it is practical to merge the RDMA changes through the
RDMA tree in the first few days of the merge window and merge the
ksmbd-for-next branch a few days later (which sounds potentially
trickier)


-- 
Thanks,

Steve

Re: [RFC PATCH 0/3] RDMA/smbdirect: introduce and use rdma_restrict_node_type()

[Leon Romanovsky]

On Tue, Feb 03, 2026 at 11:37:42AM -0600, Steve French wrote:
> On Tue, Feb 3, 2026 at 9:25 AM Stefan Metzmacher <metze@samba.org> wrote:
> >
> > Am 28.01.26 um 15:11 schrieb Leon Romanovsky:
> > > On Wed, Jan 21, 2026 at 09:07:10PM +0100, Stefan Metzmacher wrote:
> > >> Hi,
> > >>
> > >> for smbdirect it required to use different ports depending
> > >> on the RDMA protocol. E.g. for iWarp 5445 is needed
> > >> (as tcp port 445 already used by the raw tcp transport for SMB),
> > >> while InfiniBand, RoCEv1 and RoCEv2 use port 445, as they
> > >> use an independent port range (even for RoCEv2, which uses udp
> > >> port 4791 itself).
> > >>
> > >> Currently ksmbd is not able to function correctly at
> > >> all if the system has iWarp (RDMA_NODE_RNIC) interface(s)
> > >> and any InfiniBand, RoCEv1 and/or RoCEv2 interface(s)
> > >> at the same time.
> > >>
> > >> And cifs.ko uses 5445 with a fallback to 445, which
> > >> means depending on the available interfaces, it tries
> > >> 5445 in the RoCE range or may tries iWarp with 445
> > >> as a fallback. This leads to strange error messages
> > >> and strange network captures.
> > >>
> > >> To avoid these problems they will be able to
> > >> use rdma_restrict_node_type(RDMA_NODE_RNIC) before
> > >> trying port 5445 and rdma_restrict_node_type(RDMA_NODE_IB_CA)
> > >> before trying port 445. It means we'll get early
> > >> -ENODEV early from rdma_resolve_addr() without any
> > >> network traffic and timeouts.
> > >>
> > >> This is marked as RFC as I want to get feedback
> > >> if the rdma_restrict_node_type() function is acceptable
> > >> for the RDMA layer. And because the current form of
> > >> the smb patches are not tested, I only tested the
> > >> rdma part with my branch the prepares IPPROTO_SMBDIRECT
> > >> sockets.
> > >>
> > >> I'm not sure if this would be acceptable for 6.19
> > >> in order to avoid the smb layer problems, if the
> > >> RDMA layer change is only acceptable for 7.0 that's
> > >> also fine.
> > >>
> > >> This is based on the following fix applied:
> > >> smb: server: reset smb_direct_port = SMB_DIRECT_PORT_INFINIBAND on init
> > >> https://lore.kernel.org/linux-cifs/20251208154919.934760-1-metze@samba.org/
> > >> It's not yet in Linus' tree, so if this gets ready
> > >> before it's merged we can squash it.
> > >>
> > >> Stefan Metzmacher (3):
> > >>    RDMA/core: introduce rdma_restrict_node_type()
> > >>    smb: client: make use of rdma_restrict_node_type()
> > >>    smb: server: make use of rdma_restrict_node_type()
> > >
> > > The approach looks reasonable.
> >
> > Thanks!
> >
> > > Do you want me to take it through RDMA
> > > tree?
> >
> > As I also have other smb patches on top changing/using
> > it I guess it would be easier if Steve would take them.
> >
> > Steve, Leon what do you think?
> 
> I am ok with taking it via the ksmbd tree (smb3-kernel ksmbd-for-next
> branch), unless it is practical to merge the RDMA changes through the
> RDMA tree in the first few days of the merge window and merge the
> ksmbd-for-next branch a few days later (which sounds potentially
> trickier)

The latter is a common merge workflow used to avoid merge conflicts, but it
is not needed here. There are no changes in the rdma-cm area for this cycle,
so I do not expect any merge conflicts during the final days of the cycle.

Thanks

> 
> 
> -- 
> Thanks,
> 
> Steve
> 

Re: [RFC PATCH 0/3] RDMA/smbdirect: introduce and use rdma_restrict_node_type()

[Namjae Jeon]

On Thu, Jan 22, 2026 at 5:07 AM Stefan Metzmacher <metze@samba.org> wrote:
>
> Hi,
>
> for smbdirect it required to use different ports depending
> on the RDMA protocol. E.g. for iWarp 5445 is needed
> (as tcp port 445 already used by the raw tcp transport for SMB),
> while InfiniBand, RoCEv1 and RoCEv2 use port 445, as they
> use an independent port range (even for RoCEv2, which uses udp
> port 4791 itself).
>
> Currently ksmbd is not able to function correctly at
> all if the system has iWarp (RDMA_NODE_RNIC) interface(s)
> and any InfiniBand, RoCEv1 and/or RoCEv2 interface(s)
> at the same time.
>
> And cifs.ko uses 5445 with a fallback to 445, which
> means depending on the available interfaces, it tries
> 5445 in the RoCE range or may tries iWarp with 445
> as a fallback. This leads to strange error messages
> and strange network captures.
>
> To avoid these problems they will be able to
> use rdma_restrict_node_type(RDMA_NODE_RNIC) before
> trying port 5445 and rdma_restrict_node_type(RDMA_NODE_IB_CA)
> before trying port 445. It means we'll get early
> -ENODEV early from rdma_resolve_addr() without any
> network traffic and timeouts.
>
> This is marked as RFC as I want to get feedback
> if the rdma_restrict_node_type() function is acceptable
> for the RDMA layer. And because the current form of
> the smb patches are not tested, I only tested the
> rdma part with my branch the prepares IPPROTO_SMBDIRECT
> sockets.
>
> I'm not sure if this would be acceptable for 6.19
> in order to avoid the smb layer problems, if the
> RDMA layer change is only acceptable for 7.0 that's
> also fine.
>
> This is based on the following fix applied:
> smb: server: reset smb_direct_port = SMB_DIRECT_PORT_INFINIBAND on init
> https://lore.kernel.org/linux-cifs/20251208154919.934760-1-metze@samba.org/
> It's not yet in Linus' tree, so if this gets ready
> before it's merged we can squash it.
Acked-by: Namjae Jeon <linkinjeon@kernel.org>

Thanks!
>
> Stefan Metzmacher (3):
>   RDMA/core: introduce rdma_restrict_node_type()
>   smb: client: make use of rdma_restrict_node_type()
>   smb: server: make use of rdma_restrict_node_type()
>
>  drivers/infiniband/core/cma.c      |  30 ++++++++
>  drivers/infiniband/core/cma_priv.h |   1 +
>  fs/smb/client/smbdirect.c          |  26 +++++++
>  fs/smb/server/transport_rdma.c     | 108 +++++++++++++++++++++--------
>  include/rdma/rdma_cm.h             |  17 +++++
>  5 files changed, 154 insertions(+), 28 deletions(-)
>
> --
> 2.43.0
>