smb: smbdirect: introduce smbdirect_netdev_rdma_capable_mode_type()

This is basically a copy of ksmbd_rdma_capable_netdev() in the
server, but this also prints a message when a device is renamed.

The differences are:
- It uses rdma_for_each_port() instead of implementing the
  same logic again.
- It returns RDMA_NODE_{UNSPECIFIED,IB_CA,RNIC} values instead of bool

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-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

fs/smb/common/smbdirect/Makefile

@@ -14,4 +14,5 @@ smbdirect-y := \
 	smbdirect_connect.o	\
 	smbdirect_listen.o	\
 	smbdirect_accept.o	\
+	smbdirect_devices.o	\
 	smbdirect_main.o

fs/smb/common/smbdirect/smbdirect_devices.c

@@ -0,0 +1,277 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *   Copyright (C) 2017, Microsoft Corporation.
+ *   Copyright (C) 2018, LG Electronics.
+ *   Copyright (c) 2025 Stefan Metzmacher
+ */
+
+#include "smbdirect_internal.h"
+
+static u8 smbdirect_ib_device_rdma_capable_node_type(struct ib_device *ib_dev)
+{
+	if (!smbdirect_frwr_is_supported(&ib_dev->attrs))
+		return RDMA_NODE_UNSPECIFIED;
+
+	switch (ib_dev->node_type) {
+	case RDMA_NODE_IB_CA: /* Infiniband, RoCE v1 and v2 */
+	case RDMA_NODE_RNIC:  /* iWarp */
+		return ib_dev->node_type;
+	}
+
+	return RDMA_NODE_UNSPECIFIED;
+}
+
+static int smbdirect_ib_client_add(struct ib_device *ib_dev)
+{
+	u8 node_type = smbdirect_ib_device_rdma_capable_node_type(ib_dev);
+	struct smbdirect_device *sdev;
+	const char *node_str;
+	const char *action;
+	u32 pidx;
+
+	switch (node_type) {
+	case RDMA_NODE_IB_CA:
+		node_str = "IB_CA";
+		action = "added";
+		break;
+	case RDMA_NODE_RNIC:
+		node_str = "RNIC";
+		action = "added";
+		break;
+	case RDMA_NODE_UNSPECIFIED:
+		node_str = "UNSPECIFIED";
+		action = "ignored";
+		break;
+	default:
+		node_str = "UNKNOWN";
+		action = "ignored";
+		node_type = RDMA_NODE_UNSPECIFIED;
+		break;
+	}
+
+	pr_info("ib_dev[%.*s]: %s: %s %s=%u %s=0x%llx %s=0x%llx %s=0x%llx\n",
+		IB_DEVICE_NAME_MAX,
+		ib_dev->name,
+		action,
+		node_str,
+		"max_fast_reg_page_list_len",
+		ib_dev->attrs.max_fast_reg_page_list_len,
+		"device_cap_flags",
+		ib_dev->attrs.device_cap_flags,
+		"kernel_cap_flags",
+		ib_dev->attrs.kernel_cap_flags,
+		"page_size_cap",
+		ib_dev->attrs.page_size_cap);
+
+	if (node_type == RDMA_NODE_UNSPECIFIED)
+		return 0;
+
+	pr_info("ib_dev[%.*s]: %s=%u %s=%u %s=%u %s=%u %s=%u %s=%u %s=%u %s=%u %s=%u\n",
+		IB_DEVICE_NAME_MAX,
+		ib_dev->name,
+		"num_ports",
+		rdma_end_port(ib_dev),
+		"max_qp_rd_atom",
+		ib_dev->attrs.max_qp_rd_atom,
+		"max_qp_init_rd_atom",
+		ib_dev->attrs.max_qp_init_rd_atom,
+		"max_sgl_rd",
+		ib_dev->attrs.max_sgl_rd,
+		"max_sge_rd",
+		ib_dev->attrs.max_sge_rd,
+		"max_cqe",
+		ib_dev->attrs.max_cqe,
+		"max_qp_wr",
+		ib_dev->attrs.max_qp_wr,
+		"max_send_sge",
+		ib_dev->attrs.max_send_sge,
+		"max_recv_sge",
+		ib_dev->attrs.max_recv_sge);
+
+	rdma_for_each_port(ib_dev, pidx) {
+		const struct ib_port_immutable *ib_pi =
+			ib_port_immutable_read(ib_dev, pidx);
+		u32 core_cap_flags = ib_pi ? ib_pi->core_cap_flags : 0;
+
+		pr_info("ib_dev[%.*s]PORT[%u]: %s=%u %s=%u %s=%u %s=%u %s=%u %s=0x%x\n",
+			IB_DEVICE_NAME_MAX,
+			ib_dev->name,
+			pidx,
+			"iwarp",
+			rdma_protocol_iwarp(ib_dev, pidx),
+			"ib",
+			rdma_protocol_ib(ib_dev, pidx),
+			"roce",
+			rdma_protocol_roce(ib_dev, pidx),
+			"v1",
+			rdma_protocol_roce_eth_encap(ib_dev, pidx),
+			"v2",
+			rdma_protocol_roce_udp_encap(ib_dev, pidx),
+			"core_cap_flags",
+			core_cap_flags);
+	}
+
+	sdev = kzalloc_obj(*sdev);
+	if (!sdev)
+		return -ENOMEM;
+	sdev->ib_dev = ib_dev;
+	snprintf(sdev->ib_name, ARRAY_SIZE(sdev->ib_name), "%.*s",
+		 IB_DEVICE_NAME_MAX, ib_dev->name);
+
+	write_lock(&smbdirect_globals.devices.lock);
+	list_add(&sdev->list, &smbdirect_globals.devices.list);
+	write_unlock(&smbdirect_globals.devices.lock);
+
+	return 0;
+}
+
+static void smbdirect_ib_client_remove(struct ib_device *ib_dev, void *client_data)
+{
+	struct smbdirect_device *sdev, *tmp;
+
+	write_lock(&smbdirect_globals.devices.lock);
+	list_for_each_entry_safe(sdev, tmp, &smbdirect_globals.devices.list, list) {
+		if (sdev->ib_dev == ib_dev) {
+			list_del(&sdev->list);
+			pr_info("ib_dev[%.*s] removed\n",
+				IB_DEVICE_NAME_MAX, sdev->ib_name);
+			kfree(sdev);
+			break;
+		}
+	}
+	write_unlock(&smbdirect_globals.devices.lock);
+}
+
+static void smbdirect_ib_client_rename(struct ib_device *ib_dev, void *client_data)
+{
+	struct smbdirect_device *sdev;
+
+	write_lock(&smbdirect_globals.devices.lock);
+	list_for_each_entry(sdev, &smbdirect_globals.devices.list, list) {
+		if (sdev->ib_dev == ib_dev) {
+			pr_info("ib_dev[%.*s] renamed to [%.*s]\n",
+				IB_DEVICE_NAME_MAX, sdev->ib_name,
+				IB_DEVICE_NAME_MAX, ib_dev->name);
+			snprintf(sdev->ib_name, ARRAY_SIZE(sdev->ib_name), "%.*s",
+				 IB_DEVICE_NAME_MAX, ib_dev->name);
+			break;
+		}
+	}
+	write_unlock(&smbdirect_globals.devices.lock);
+}
+
+static struct ib_client smbdirect_ib_client = {
+	.name	= "smbdirect_ib_client",
+	.add	= smbdirect_ib_client_add,
+	.remove	= smbdirect_ib_client_remove,
+	.rename	= smbdirect_ib_client_rename,
+};
+
+static u8 smbdirect_netdev_find_rdma_capable_node_type(struct net_device *netdev)
+{
+	struct smbdirect_device *sdev;
+	u8 node_type = RDMA_NODE_UNSPECIFIED;
+
+	read_lock(&smbdirect_globals.devices.lock);
+	list_for_each_entry(sdev, &smbdirect_globals.devices.list, list) {
+		u32 pi;
+
+		rdma_for_each_port(sdev->ib_dev, pi) {
+			struct net_device *ndev;
+
+			ndev = ib_device_get_netdev(sdev->ib_dev, pi);
+			if (!ndev)
+				continue;
+
+			if (ndev == netdev) {
+				dev_put(ndev);
+				node_type = sdev->ib_dev->node_type;
+				goto out;
+			}
+			dev_put(ndev);
+		}
+	}
+out:
+	read_unlock(&smbdirect_globals.devices.lock);
+
+	if (node_type == RDMA_NODE_UNSPECIFIED) {
+		struct ib_device *ibdev;
+
+		ibdev = ib_device_get_by_netdev(netdev, RDMA_DRIVER_UNKNOWN);
+		if (ibdev) {
+			node_type = smbdirect_ib_device_rdma_capable_node_type(ibdev);
+			ib_device_put(ibdev);
+		}
+	}
+
+	return node_type;
+}
+
+/*
+ * Returns RDMA_NODE_UNSPECIFIED when the netdev has
+ * no support for smbdirect capable rdma.
+ *
+ * Otherwise RDMA_NODE_RNIC is returned for iwarp devices
+ * and RDMA_NODE_IB_CA or Infiniband and RoCE (v1 and v2)
+ */
+u8 smbdirect_netdev_rdma_capable_node_type(struct net_device *netdev)
+{
+	struct net_device *lower_dev;
+	struct list_head *iter;
+	u8 node_type = RDMA_NODE_UNSPECIFIED;
+
+	node_type = smbdirect_netdev_find_rdma_capable_node_type(netdev);
+	if (node_type != RDMA_NODE_UNSPECIFIED)
+		return node_type;
+
+	/* check if netdev is bridge or VLAN */
+	if (netif_is_bridge_master(netdev) || netdev->priv_flags & IFF_802_1Q_VLAN)
+		netdev_for_each_lower_dev(netdev, lower_dev, iter) {
+			node_type = smbdirect_netdev_find_rdma_capable_node_type(lower_dev);
+			if (node_type != RDMA_NODE_UNSPECIFIED)
+				return node_type;
+		}
+
+	/* check if netdev is IPoIB safely without layer violation */
+	if (netdev->type == ARPHRD_INFINIBAND)
+		return RDMA_NODE_IB_CA;
+
+	return RDMA_NODE_UNSPECIFIED;
+}
+__SMBDIRECT_EXPORT_SYMBOL__(smbdirect_netdev_rdma_capable_node_type);
+
+__init int smbdirect_devices_init(void)
+{
+	int ret;
+
+	rwlock_init(&smbdirect_globals.devices.lock);
+	INIT_LIST_HEAD(&smbdirect_globals.devices.list);
+
+	ret = ib_register_client(&smbdirect_ib_client);
+	if (ret) {
+		pr_crit("failed to ib_register_client: %d %1pe\n",
+			ret, SMBDIRECT_DEBUG_ERR_PTR(ret));
+		return ret;
+	}
+
+	return 0;
+}
+
+__exit void smbdirect_devices_exit(void)
+{
+	struct smbdirect_device *sdev, *tmp;
+
+	/*
+	 * On exist we just cleanup so that
+	 * smbdirect_ib_client_remove() won't
+	 * print removals of devices.
+	 */
+	write_lock(&smbdirect_globals.devices.lock);
+	list_for_each_entry_safe(sdev, tmp, &smbdirect_globals.devices.list, list) {
+		list_del(&sdev->list);
+		kfree(sdev);
+	}
+	write_unlock(&smbdirect_globals.devices.lock);
+
+	ib_unregister_client(&smbdirect_ib_client);
+}

fs/smb/common/smbdirect/smbdirect_internal.h

@@ -18,12 +18,27 @@
 
 struct smbdirect_module_state {
 	struct mutex mutex;
+
+	struct {
+		rwlock_t lock;
+		struct list_head list;
+	} devices;
 };
 
 extern struct smbdirect_module_state smbdirect_globals;
 
 #include "smbdirect_socket.h"
 
+struct smbdirect_device {
+	struct list_head list;
+	struct ib_device *ib_dev;
+	/*
+	 * copy of ib_dev->name,
+	 * in order to print renames
+	 */
+	char ib_name[IB_DEVICE_NAME_MAX];
+};
+
 #ifdef SMBDIRECT_USE_INLINE_C_FILES
 /* this is temporary while this file is included in others */
 #define __SMBDIRECT_PRIVATE__ __maybe_unused static
@@ -143,4 +158,7 @@ void smbdirect_connection_destroy_mr_list(struct smbdirect_socket *sc);
 
 void smbdirect_accept_negotiate_finish(struct smbdirect_socket *sc, u32 ntstatus);
 
+__init int smbdirect_devices_init(void);
+__exit void smbdirect_devices_exit(void);
+
 #endif /* __FS_SMB_COMMON_SMBDIRECT_INTERNAL_H__ */

fs/smb/common/smbdirect/smbdirect_main.c

@@ -12,14 +12,24 @@ struct smbdirect_module_state smbdirect_globals = {
 
 static __init int smbdirect_module_init(void)
 {
+	int ret;
+
 	pr_notice("subsystem loading...\n");
 	mutex_lock(&smbdirect_globals.mutex);
 
-	/* TODO... */
+	ret = smbdirect_devices_init();
+	if (ret)
+		goto devices_init_failed;
 
 	mutex_unlock(&smbdirect_globals.mutex);
 	pr_notice("subsystem loaded\n");
 	return 0;
+
+devices_init_failed:
+	mutex_unlock(&smbdirect_globals.mutex);
+	pr_crit("failed to loaded: %d (%1pe)\n",
+		ret, SMBDIRECT_DEBUG_ERR_PTR(ret));
+	return ret;
 }
 
 static __exit void smbdirect_module_exit(void)
@@ -27,7 +37,7 @@ static __exit void smbdirect_module_exit(void)
 	pr_notice("subsystem unloading...\n");
 	mutex_lock(&smbdirect_globals.mutex);
 
-	/* TODO... */
+	smbdirect_devices_exit();
 
 	mutex_unlock(&smbdirect_globals.mutex);
 	pr_notice("subsystem unloaded\n");

fs/smb/common/smbdirect/smbdirect_public.h

@@ -24,6 +24,9 @@ struct smbdirect_mr_io;
 
 #include <rdma/rw.h>
 
+__SMBDIRECT_PUBLIC__
+u8 smbdirect_netdev_rdma_capable_node_type(struct net_device *netdev);
+
 __SMBDIRECT_PUBLIC__
 bool smbdirect_frwr_is_supported(const struct ib_device_attr *attrs);