From: Parav Pandit <parav@xxxxxxxxxxxx>
Implement compatibility layer sysfs entries of ib_core so that non
init_net net namespaces can also discover rdma devices.
Each non init_net net namespace has ib_core_device created in it.
Such ib_core_device sysfs tree resembles rdma devices found in
init_net namespace.
This allows discovering rdma devices in multiple non init_net
net namespaces via sysfs entries and helpful to rdma-core userspace.
Signed-off-by: Parav Pandit <parav@xxxxxxxxxxxx>
Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxxxx>
---
drivers/infiniband/core/device.c | 261 ++++++++++++++++++++++++++++++-
include/rdma/ib_verbs.h | 6 +
2 files changed, 263 insertions(+), 4 deletions(-)
diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c
index 270222602f54..5c911bc451af 100644
--- a/drivers/infiniband/core/device.c
+++ b/drivers/infiniband/core/device.c
@@ -38,6 +38,8 @@
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/netdevice.h>
+#include <net/net_namespace.h>
+#include <net/netns/generic.h>
#include <linux/security.h>
#include <linux/notifier.h>
#include <linux/hashtable.h>
@@ -101,6 +103,30 @@ static DECLARE_RWSEM(clients_rwsem);
* be registered.
*/
#define CLIENT_DATA_REGISTERED XA_MARK_1
+
+/**
+ * struct rdma_dev_net - rdma net namespace metadata for a net
+ * @net: Pointer to owner net namespace
+ * @id: xarray id to identify the net namespace.
+ */
+struct rdma_dev_net {
+ possible_net_t net;
+ u32 id;
+};
+
+static unsigned int rdma_dev_net_id;
+
+/*
+ * A list of net namespaces is maintained in an xarray. This is necessary
+ * because we can't get the locking right using the existing net ns list. We
+ * would require a init_net callback after the list is updated.
+ */
+static DEFINE_XARRAY_FLAGS(rdma_nets, XA_FLAGS_ALLOC);
+/*
+ * rwsem to protect accessing the rdma_nets xarray entries.
+ */
+static DECLARE_RWSEM(rdma_nets_rwsem);
+
/*
* xarray has this behavior where it won't iterate over NULL values stored in
* allocated arrays. So we need our own iterator to see all values stored in
@@ -268,6 +294,26 @@ struct ib_device *ib_device_get_by_name(const char *name,
}
EXPORT_SYMBOL(ib_device_get_by_name);
+static int rename_compat_devs(struct ib_device *device)
+{
+ struct ib_core_device *cdev;
+ unsigned long index;
+ int ret = 0;
+
+ mutex_lock(&device->compat_devs_mutex);
+ xa_for_each (&device->compat_devs, index, cdev) {
+ ret = device_rename(&cdev->dev, dev_name(&device->dev));
+ if (ret) {
+ dev_warn(&cdev->dev,
+ "Fail to rename compatdev to new name %s\n",
+ dev_name(&device->dev));
+ break;
+ }
+ }
+ mutex_unlock(&device->compat_devs_mutex);
+ return ret;
+}
+
int ib_device_rename(struct ib_device *ibdev, const char *name)
{
int ret;
@@ -287,6 +333,7 @@ int ib_device_rename(struct ib_device *ibdev, const char *name)
if (ret)
goto out;
strlcpy(ibdev->name, name, IB_DEVICE_NAME_MAX);
+ ret = rename_compat_devs(ibdev);
out:
up_write(&devices_rwsem);
return ret;
@@ -336,6 +383,7 @@ static void ib_device_release(struct device *device)
WARN_ON(refcount_read(&dev->refcount));
ib_cache_release_one(dev);
ib_security_release_port_pkey_list(dev);
+ xa_destroy(&dev->compat_devs);
xa_destroy(&dev->client_data);
if (dev->port_data)
kfree_rcu(container_of(dev->port_data, struct ib_port_data_rcu,
@@ -359,7 +407,10 @@ static int ib_device_uevent(struct device *device,
static const void *net_namespace(struct device *d)
{
- return &init_net;
+ struct ib_core_device *coredev =
+ container_of(d, struct ib_core_device, dev);
+
+ return read_pnet(&coredev->rdma_net);
}
static struct class ib_class = {
@@ -371,7 +422,7 @@ static struct class ib_class = {
};
static void rdma_init_coredev(struct ib_core_device *coredev,
- struct ib_device *dev)
+ struct ib_device *dev, struct net *net)
{
/* This BUILD_BUG_ON is intended to catch layout change
* of union of ib_core_device and device.
@@ -387,6 +438,7 @@ static void rdma_init_coredev(struct ib_core_device *coredev,
device_initialize(&coredev->dev);
coredev->owner = dev;
INIT_LIST_HEAD(&coredev->port_list);
+ write_pnet(&coredev->rdma_net, net);
}
/**
@@ -416,7 +468,7 @@ struct ib_device *_ib_alloc_device(size_t size)
}
device->groups[0] = &ib_dev_attr_group;
- rdma_init_coredev(&device->coredev, device);
+ rdma_init_coredev(&device->coredev, device, &init_net);
INIT_LIST_HEAD(&device->event_handler_list);
spin_lock_init(&device->event_handler_lock);
@@ -427,6 +479,8 @@ struct ib_device *_ib_alloc_device(size_t size)
*/
xa_init_flags(&device->client_data, XA_FLAGS_ALLOC);
init_rwsem(&device->client_data_rwsem);
+ xa_init_flags(&device->compat_devs, XA_FLAGS_ALLOC);
+ mutex_init(&device->compat_devs_mutex);
init_completion(&device->unreg_completion);
INIT_WORK(&device->unregistration_work, ib_unregister_work);
@@ -459,6 +513,7 @@ void ib_dealloc_device(struct ib_device *device)
/* Expedite releasing netdev references */
free_netdevs(device);
+ WARN_ON(!xa_empty(&device->compat_devs));
WARN_ON(!xa_empty(&device->client_data));
WARN_ON(refcount_read(&device->refcount));
rdma_restrack_clean(device);
@@ -667,6 +722,180 @@ static int ib_security_change(struct notifier_block *nb, unsigned long event,
return NOTIFY_OK;
}
+static void compatdev_release(struct device *dev)
+{
+ struct ib_core_device *cdev =
+ container_of(dev, struct ib_core_device, dev);
+
+ kfree(cdev);
+}
+
+static int add_one_compat_dev(struct ib_device *device,
+ struct rdma_dev_net *rnet)
+{
+ struct ib_core_device *cdev;
+ int ret;
+
+ /*
+ * Create and add compat device in all namespaces other than where it
+ * is currently bound to.
+ */
+ if (net_eq(read_pnet(&rnet->net),
+ read_pnet(&device->coredev.rdma_net)))
+ return 0;
+
+ /*
+ * The first of init_net() or ib_register_device() to take the
+ * compat_devs_mutex wins and gets to add the device. Others will wait
+ * for completion here.
+ */
+ mutex_lock(&device->compat_devs_mutex);
+ cdev = xa_load(&device->compat_devs, rnet->id);
+ if (cdev) {
+ ret = 0;
+ goto done;
+ }
+ ret = xa_reserve(&device->compat_devs, rnet->id, GFP_KERNEL);
+ if (ret)
+ goto done;
+
+ cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
+ if (!cdev) {
+ ret = -ENOMEM;
+ goto cdev_err;
+ }
+
+ cdev->dev.parent = device->dev.parent;
+ rdma_init_coredev(cdev, device, read_pnet(&rnet->net));
+ cdev->dev.release = compatdev_release;
+ dev_set_name(&cdev->dev, "%s", dev_name(&device->dev));
+
+ ret = device_add(&cdev->dev);
+ if (ret)
+ goto add_err;
+
+ ret = xa_err(xa_store(&device->compat_devs, rnet->id,
+ cdev, GFP_KERNEL));
+ if (ret)
+ goto insert_err;
+
+ mutex_unlock(&device->compat_devs_mutex);
+ return 0;
+
+insert_err:
+ device_del(&cdev->dev);
+add_err:
+ put_device(&cdev->dev);
+cdev_err:
+ xa_release(&device->compat_devs, rnet->id);
+done:
+ mutex_unlock(&device->compat_devs_mutex);
+ return ret;
+}
+
+static void remove_one_compat_dev(struct ib_device *device, u32 id)
+{
+ struct ib_core_device *cdev;
+
+ mutex_lock(&device->compat_devs_mutex);
+ cdev = xa_erase(&device->compat_devs, id);
+ mutex_unlock(&device->compat_devs_mutex);
+ if (cdev) {
+ device_del(&cdev->dev);
+ put_device(&cdev->dev);
+ }
+}
+
+static void remove_compat_devs(struct ib_device *device)
+{
+ struct ib_core_device *cdev;
+ unsigned long index;
+
+ xa_for_each (&device->compat_devs, index, cdev)
+ remove_one_compat_dev(device, index);
+}
+
+static int add_compat_devs(struct ib_device *device)
+{
+ struct rdma_dev_net *rnet;
+ unsigned long index;
+ int ret = 0;
+
+ down_read(&rdma_nets_rwsem);
+ xa_for_each (&rdma_nets, index, rnet) {
+ ret = add_one_compat_dev(device, rnet);
+ if (ret)
+ break;
+ }
+ up_read(&rdma_nets_rwsem);
+ return ret;
+}
+
+static void rdma_dev_exit_net(struct net *net)
+{
+ struct rdma_dev_net *rnet = net_generic(net, rdma_dev_net_id);
+ struct ib_device *dev;
+ unsigned long index;
+ int ret;
+
+ down_write(&rdma_nets_rwsem);
+ /*
+ * Prevent the ID from being re-used and hide the id from xa_for_each.
+ */
+ ret = xa_err(xa_store(&rdma_nets, rnet->id, NULL, GFP_KERNEL));
+ WARN_ON(ret);
+ up_write(&rdma_nets_rwsem);
+
+ down_read(&devices_rwsem);
+ xa_for_each (&devices, index, dev) {
+ get_device(&dev->dev);
+ /*
+ * Release the devices_rwsem so that pontentially blocking
+ * device_del, doesn't hold the devices_rwsem for too long.
+ */
+ up_read(&devices_rwsem);
+
+ remove_one_compat_dev(dev, rnet->id);
+
+ put_device(&dev->dev);
+ down_read(&devices_rwsem);
+ }
+ up_read(&devices_rwsem);
+
+ xa_erase(&rdma_nets, rnet->id);
+}
+
+static __net_init int rdma_dev_init_net(struct net *net)
+{
+ struct rdma_dev_net *rnet = net_generic(net, rdma_dev_net_id);
+ unsigned long index;
+ struct ib_device *dev;
+ int ret;
+
+ /* No need to create any compat devices in default init_net. */
+ if (net_eq(net, &init_net))
+ return 0;
+
+ write_pnet(&rnet->net, net);
+
+ ret = xa_alloc(&rdma_nets, &rnet->id, U32_MAX, rnet, GFP_KERNEL);
+ if (ret)
+ return ret;
+
+ down_read(&devices_rwsem);
+ xa_for_each_marked (&devices, index, dev, DEVICE_REGISTERED) {
+ ret = add_one_compat_dev(dev, rnet);
+ if (ret)
+ break;
+ }
+ up_read(&devices_rwsem);
+
+ if (ret)
+ rdma_dev_exit_net(net);
+
+ return ret;
+}
+
/*
* Assign the unique string device name and the unique device index. This is
* undone by ib_dealloc_device.
@@ -797,6 +1026,13 @@ static void disable_device(struct ib_device *device)
ib_device_put(device);
wait_for_completion(&device->unreg_completion);
+ /*
+ * compat devices must be removed after device refcount drops to zero.
+ * Otherwise init_net() may add more compatdevs after removing compat
+ * devices and before device is disabled.
+ */
+ remove_compat_devs(device);
+
/* Expedite removing unregistered pointers from the hash table */
free_netdevs(device);
}
@@ -839,7 +1075,8 @@ static int enable_device_and_get(struct ib_device *device)
break;
}
up_read(&clients_rwsem);
-
+ if (!ret)
+ ret = add_compat_devs(device);
out:
up_read(&devices_rwsem);
return ret;
@@ -1070,6 +1307,13 @@ void ib_unregister_device_queued(struct ib_device *ib_dev)
}
EXPORT_SYMBOL(ib_unregister_device_queued);
+static struct pernet_operations rdma_dev_net_ops = {
+ .init = rdma_dev_init_net,
+ .exit = rdma_dev_exit_net,
+ .id = &rdma_dev_net_id,
+ .size = sizeof(struct rdma_dev_net),
+};
+
static int assign_client_id(struct ib_client *client)
{
int ret;
@@ -1934,12 +2178,20 @@ static int __init ib_core_init(void)
goto err_sa;
}
+ ret = register_pernet_device(&rdma_dev_net_ops);
+ if (ret) {
+ pr_warn("Couldn't init compat dev. ret %d\n", ret);
+ goto err_compat;
+ }
+
nldev_init();
rdma_nl_register(RDMA_NL_LS, ibnl_ls_cb_table);
roce_gid_mgmt_init();
return 0;
+err_compat:
+ unregister_lsm_notifier(&ibdev_lsm_nb);
err_sa:
ib_sa_cleanup();
err_mad:
@@ -1964,6 +2216,7 @@ static void __exit ib_core_cleanup(void)
roce_gid_mgmt_cleanup();
nldev_exit();
rdma_nl_unregister(RDMA_NL_LS);
+ unregister_pernet_device(&rdma_dev_net_ops);
unregister_lsm_notifier(&ibdev_lsm_nb);
ib_sa_cleanup();
ib_mad_cleanup();
diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index 5f9f4fcdc4cc..d42267e72c4b 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -2559,6 +2559,7 @@ struct ib_core_device {
* union of ib_core_device and device exists in ib_device.
*/
struct device dev;
+ possible_net_t rdma_net;
struct kobject *ports_kobj;
struct list_head port_list;
struct ib_device *owner; /* reach back to owner ib_device */
@@ -2636,6 +2637,11 @@ struct ib_device {
struct work_struct unregistration_work;
const struct rdma_link_ops *link_ops;
+
+ /* Protects compat_devs xarray modifications */
+ struct mutex compat_devs_mutex;
+ /* Maintains compat devices for each net namespace */
+ struct xarray compat_devs;
};
struct ib_client {
--
2.19.1
