[PATCH rdma-next 03/13] RDMA/core: Support renaming a device when changing its net namespace
From: Jiri Pirko <jiri@resnulli.us>
Date: 2026-07-09 09:55:47
Also in:
cgroups, linux-kselftest, linux-rdma, linux-s390
Subsystem:
infiniband subsystem, the rest · Maintainers:
Jason Gunthorpe, Leon Romanovsky, Linus Torvalds
From: Jiri Pirko <redacted> Allow namespace moves to request a destination device name. Keep requested names on the same literal-name path as the existing RDMA rename operation, and keep teardown fallback naming on the trusted kernel-controlled path. Signed-off-by: Jiri Pirko <redacted> --- drivers/infiniband/core/core_priv.h | 2 +- drivers/infiniband/core/device.c | 48 ++++++++++++++++++++--------- drivers/infiniband/core/nldev.c | 2 +- 3 files changed, 35 insertions(+), 17 deletions(-)
diff --git a/drivers/infiniband/core/core_priv.h b/drivers/infiniband/core/core_priv.h
index 19104c542b27..3bd5bb7135a3 100644
--- a/drivers/infiniband/core/core_priv.h
+++ b/drivers/infiniband/core/core_priv.h@@ -356,7 +356,7 @@ void ib_port_unregister_client_groups(struct ib_device *ibdev, u32 port_num, const struct attribute_group **groups); int ib_device_set_netns_put(struct sk_buff *skb, - struct ib_device *dev, u32 ns_fd); + struct ib_device *dev, u32 ns_fd, const char *name); int rdma_nl_net_init(struct rdma_dev_net *rnet); void rdma_nl_net_exit(struct rdma_dev_net *rnet);
diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c
index 8d169658e312..191f05898bae 100644
--- a/drivers/infiniband/core/device.c
+++ b/drivers/infiniband/core/device.c@@ -268,7 +268,8 @@ static struct notifier_block ibdev_lsm_nb = { }; static int rdma_dev_change_netns(struct ib_device *device, struct net *cur_net, - struct net *net, const char *fallback_pattern); + struct net *net, const char *requested_name, + const char *fallback_pattern); /* Pointer to the RCU head at the start of the ib_port_data array */ struct ib_port_data_rcu {
@@ -1173,7 +1174,7 @@ static void rdma_dev_exit_net(struct net *net) */ if (net_eq(net, read_pnet(&dev->coredev.rdma_net))) { ret = rdma_dev_change_netns(dev, net, &init_net, - "ibdev%d"); + NULL, "ibdev%d"); if (ret) WARN(1, "Failed to move RDMA device %s to init_net on netns exit: %d\n",
@@ -1714,12 +1715,13 @@ static bool rdma_dev_name_in_netns(struct ib_device *skip, struct net *net, } /* - * Choose the name @device should use in net namespace @net: keep the current - * name when it is free, otherwise use a trusted '%d' @fallback_pattern - * (namespace teardown) to pick a free index. The caller must hold the write - * side of devices_rwsem. + * Choose the name @device should use in net namespace @net. @requested_name + * is used as a literal device name when set. Otherwise keep the current name + * when it is free, or use a trusted '%d' @fallback_pattern for teardown. The + * caller must hold the write side of devices_rwsem. */ static int rdma_dev_pick_netns_name(struct ib_device *device, struct net *net, + const char *requested_name, const char *fallback_pattern, char *buf, size_t buf_len, const char **new_name)
@@ -1728,6 +1730,15 @@ static int rdma_dev_pick_netns_name(struct ib_device *device, struct net *net, lockdep_assert_held_write(&devices_rwsem); + if (requested_name) { + if (!rdma_dev_name_in_netns(device, net, requested_name)) { + *new_name = requested_name; + return 0; + } + + return -EEXIST; + } + if (!rdma_dev_name_in_netns(device, net, dev_name(&device->dev))) { *new_name = dev_name(&device->dev); return 0;
@@ -1758,7 +1769,8 @@ static int rdma_dev_pick_netns_name(struct ib_device *device, struct net *net, * Naming rules are handled by rdma_dev_pick_netns_name(). */ static int rdma_dev_change_netns(struct ib_device *device, struct net *cur_net, - struct net *net, const char *fallback_pattern) + struct net *net, const char *requested_name, + const char *fallback_pattern) { char buf[IB_DEVICE_NAME_MAX]; const char *new_name;
@@ -1784,8 +1796,9 @@ static int rdma_dev_change_netns(struct ib_device *device, struct net *cur_net, * down, so a doomed user move does not disable a live device. */ down_write(&devices_rwsem); - ret = rdma_dev_pick_netns_name(device, net, fallback_pattern, - buf, sizeof(buf), &new_name); + ret = rdma_dev_pick_netns_name(device, net, requested_name, + fallback_pattern, buf, + sizeof(buf), &new_name); up_write(&devices_rwsem); if (ret) goto out;
@@ -1801,8 +1814,9 @@ static int rdma_dev_change_netns(struct ib_device *device, struct net *cur_net, * level. */ down_write(&devices_rwsem); - ret = rdma_dev_pick_netns_name(device, net, fallback_pattern, buf, - sizeof(buf), &new_name); + ret = rdma_dev_pick_netns_name(device, net, requested_name, + fallback_pattern, buf, sizeof(buf), + &new_name); if (ret) { if (fallback_pattern) { WARN(1,
@@ -1857,7 +1871,7 @@ static int rdma_dev_change_netns(struct ib_device *device, struct net *cur_net, } int ib_device_set_netns_put(struct sk_buff *skb, - struct ib_device *dev, u32 ns_fd) + struct ib_device *dev, u32 ns_fd, const char *name) { struct net *net; int ret;
@@ -1873,9 +1887,12 @@ int ib_device_set_netns_put(struct sk_buff *skb, goto ns_err; } - /* Moving a device to the namespace it already lives in is a no-op. */ + /* + * Moving a device to the namespace it already lives in is a no-op; a + * supplied name still renames it in place. + */ if (net_eq(net, read_pnet(&dev->coredev.rdma_net))) { - ret = 0; + ret = name ? ib_device_rename(dev, name) : 0; goto ns_err; }
@@ -1891,7 +1908,8 @@ int ib_device_set_netns_put(struct sk_buff *skb, get_device(&dev->dev); ib_device_put(dev); - ret = rdma_dev_change_netns(dev, current->nsproxy->net_ns, net, NULL); + ret = rdma_dev_change_netns(dev, current->nsproxy->net_ns, net, name, + NULL); put_device(&dev->dev); put_net(net);
diff --git a/drivers/infiniband/core/nldev.c b/drivers/infiniband/core/nldev.c
index 3a9ec43a16f1..3540cb0b9d4f 100644
--- a/drivers/infiniband/core/nldev.c
+++ b/drivers/infiniband/core/nldev.c@@ -1194,7 +1194,7 @@ static int nldev_set_doit(struct sk_buff *skb, struct nlmsghdr *nlh, u32 ns_fd; ns_fd = nla_get_u32(tb[RDMA_NLDEV_NET_NS_FD]); - err = ib_device_set_netns_put(skb, device, ns_fd); + err = ib_device_set_netns_put(skb, device, ns_fd, NULL); if (err == -EEXIST) NL_SET_ERR_MSG(extack, "Device name already exists in the target net namespace");
--
2.54.0