OpenCloudOS-Kernel/net/devlink/core.c

319 lines
7.6 KiB
C
Raw Normal View History

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (c) 2016 Mellanox Technologies. All rights reserved.
* Copyright (c) 2016 Jiri Pirko <jiri@mellanox.com>
*/
#include <net/genetlink.h>
#include "devl_internal.h"
DEFINE_XARRAY_FLAGS(devlinks, XA_FLAGS_ALLOC);
void *devlink_priv(struct devlink *devlink)
{
return &devlink->priv;
}
EXPORT_SYMBOL_GPL(devlink_priv);
struct devlink *priv_to_devlink(void *priv)
{
return container_of(priv, struct devlink, priv);
}
EXPORT_SYMBOL_GPL(priv_to_devlink);
struct device *devlink_to_dev(const struct devlink *devlink)
{
return devlink->dev;
}
EXPORT_SYMBOL_GPL(devlink_to_dev);
struct net *devlink_net(const struct devlink *devlink)
{
return read_pnet(&devlink->_net);
}
EXPORT_SYMBOL_GPL(devlink_net);
void devl_assert_locked(struct devlink *devlink)
{
lockdep_assert_held(&devlink->lock);
}
EXPORT_SYMBOL_GPL(devl_assert_locked);
#ifdef CONFIG_LOCKDEP
/* For use in conjunction with LOCKDEP only e.g. rcu_dereference_protected() */
bool devl_lock_is_held(struct devlink *devlink)
{
return lockdep_is_held(&devlink->lock);
}
EXPORT_SYMBOL_GPL(devl_lock_is_held);
#endif
void devl_lock(struct devlink *devlink)
{
mutex_lock(&devlink->lock);
}
EXPORT_SYMBOL_GPL(devl_lock);
int devl_trylock(struct devlink *devlink)
{
return mutex_trylock(&devlink->lock);
}
EXPORT_SYMBOL_GPL(devl_trylock);
void devl_unlock(struct devlink *devlink)
{
mutex_unlock(&devlink->lock);
}
EXPORT_SYMBOL_GPL(devl_unlock);
/**
* devlink_try_get() - try to obtain a reference on a devlink instance
* @devlink: instance to reference
*
* Obtain a reference on a devlink instance. A reference on a devlink instance
* only implies that it's safe to take the instance lock. It does not imply
* that the instance is registered, use devl_is_registered() after taking
* the instance lock to check registration status.
*/
struct devlink *__must_check devlink_try_get(struct devlink *devlink)
{
if (refcount_inc_not_zero(&devlink->refcount))
return devlink;
return NULL;
}
static void devlink_release(struct work_struct *work)
{
struct devlink *devlink;
devlink = container_of(to_rcu_work(work), struct devlink, rwork);
mutex_destroy(&devlink->lock);
lockdep_unregister_key(&devlink->lock_key);
kfree(devlink);
}
void devlink_put(struct devlink *devlink)
{
if (refcount_dec_and_test(&devlink->refcount))
queue_rcu_work(system_wq, &devlink->rwork);
}
struct devlink *devlinks_xa_find_get(struct net *net, unsigned long *indexp)
{
struct devlink *devlink = NULL;
rcu_read_lock();
retry:
devlink = xa_find(&devlinks, indexp, ULONG_MAX, DEVLINK_REGISTERED);
if (!devlink)
goto unlock;
if (!devlink_try_get(devlink))
goto next;
if (!net_eq(devlink_net(devlink), net)) {
devlink_put(devlink);
goto next;
}
unlock:
rcu_read_unlock();
return devlink;
next:
(*indexp)++;
goto retry;
}
/**
devlink: remove the registration guarantee of references The objective of exposing the devlink instance locks to drivers was to let them use these locks to prevent user space from accessing the device before it's fully initialized. This is difficult because devlink_unregister() waits for all references to be released, meaning that devlink_unregister() can't itself be called under the instance lock. To avoid this issue devlink_register() was moved after subobject registration a while ago. Unfortunately the netdev paths get a hold of the devlink instances _before_ they are registered. Ideally netdev should wait for devlink init to finish (synchronizing on the instance lock). This can't work because we don't know if the instance will _ever_ be registered (in case of failures it may not). The other option of returning an error until devlink_register() is called is unappealing (user space would get a notification netdev exist but would have to wait arbitrary amount of time before accessing some of its attributes). Weaken the guarantees of the devlink references. Holding a reference will now only guarantee that the memory of the object is around. Another way of looking at it is that the reference now protects the object not its "registered" status. Use devlink instance lock to synchronize unregistration. This implies that releasing of the "main" reference of the devlink instance moves from devlink_unregister() to devlink_free(). Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-01-06 14:33:58 +08:00
* devl_register - Register devlink instance
* @devlink: devlink
*/
devlink: remove the registration guarantee of references The objective of exposing the devlink instance locks to drivers was to let them use these locks to prevent user space from accessing the device before it's fully initialized. This is difficult because devlink_unregister() waits for all references to be released, meaning that devlink_unregister() can't itself be called under the instance lock. To avoid this issue devlink_register() was moved after subobject registration a while ago. Unfortunately the netdev paths get a hold of the devlink instances _before_ they are registered. Ideally netdev should wait for devlink init to finish (synchronizing on the instance lock). This can't work because we don't know if the instance will _ever_ be registered (in case of failures it may not). The other option of returning an error until devlink_register() is called is unappealing (user space would get a notification netdev exist but would have to wait arbitrary amount of time before accessing some of its attributes). Weaken the guarantees of the devlink references. Holding a reference will now only guarantee that the memory of the object is around. Another way of looking at it is that the reference now protects the object not its "registered" status. Use devlink instance lock to synchronize unregistration. This implies that releasing of the "main" reference of the devlink instance moves from devlink_unregister() to devlink_free(). Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-01-06 14:33:58 +08:00
int devl_register(struct devlink *devlink)
{
ASSERT_DEVLINK_NOT_REGISTERED(devlink);
devlink: remove the registration guarantee of references The objective of exposing the devlink instance locks to drivers was to let them use these locks to prevent user space from accessing the device before it's fully initialized. This is difficult because devlink_unregister() waits for all references to be released, meaning that devlink_unregister() can't itself be called under the instance lock. To avoid this issue devlink_register() was moved after subobject registration a while ago. Unfortunately the netdev paths get a hold of the devlink instances _before_ they are registered. Ideally netdev should wait for devlink init to finish (synchronizing on the instance lock). This can't work because we don't know if the instance will _ever_ be registered (in case of failures it may not). The other option of returning an error until devlink_register() is called is unappealing (user space would get a notification netdev exist but would have to wait arbitrary amount of time before accessing some of its attributes). Weaken the guarantees of the devlink references. Holding a reference will now only guarantee that the memory of the object is around. Another way of looking at it is that the reference now protects the object not its "registered" status. Use devlink instance lock to synchronize unregistration. This implies that releasing of the "main" reference of the devlink instance moves from devlink_unregister() to devlink_free(). Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-01-06 14:33:58 +08:00
devl_assert_locked(devlink);
xa_set_mark(&devlinks, devlink->index, DEVLINK_REGISTERED);
devlink_notify_register(devlink);
devlink: remove the registration guarantee of references The objective of exposing the devlink instance locks to drivers was to let them use these locks to prevent user space from accessing the device before it's fully initialized. This is difficult because devlink_unregister() waits for all references to be released, meaning that devlink_unregister() can't itself be called under the instance lock. To avoid this issue devlink_register() was moved after subobject registration a while ago. Unfortunately the netdev paths get a hold of the devlink instances _before_ they are registered. Ideally netdev should wait for devlink init to finish (synchronizing on the instance lock). This can't work because we don't know if the instance will _ever_ be registered (in case of failures it may not). The other option of returning an error until devlink_register() is called is unappealing (user space would get a notification netdev exist but would have to wait arbitrary amount of time before accessing some of its attributes). Weaken the guarantees of the devlink references. Holding a reference will now only guarantee that the memory of the object is around. Another way of looking at it is that the reference now protects the object not its "registered" status. Use devlink instance lock to synchronize unregistration. This implies that releasing of the "main" reference of the devlink instance moves from devlink_unregister() to devlink_free(). Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-01-06 14:33:58 +08:00
return 0;
}
EXPORT_SYMBOL_GPL(devl_register);
void devlink_register(struct devlink *devlink)
{
devl_lock(devlink);
devl_register(devlink);
devl_unlock(devlink);
}
EXPORT_SYMBOL_GPL(devlink_register);
/**
devlink: remove the registration guarantee of references The objective of exposing the devlink instance locks to drivers was to let them use these locks to prevent user space from accessing the device before it's fully initialized. This is difficult because devlink_unregister() waits for all references to be released, meaning that devlink_unregister() can't itself be called under the instance lock. To avoid this issue devlink_register() was moved after subobject registration a while ago. Unfortunately the netdev paths get a hold of the devlink instances _before_ they are registered. Ideally netdev should wait for devlink init to finish (synchronizing on the instance lock). This can't work because we don't know if the instance will _ever_ be registered (in case of failures it may not). The other option of returning an error until devlink_register() is called is unappealing (user space would get a notification netdev exist but would have to wait arbitrary amount of time before accessing some of its attributes). Weaken the guarantees of the devlink references. Holding a reference will now only guarantee that the memory of the object is around. Another way of looking at it is that the reference now protects the object not its "registered" status. Use devlink instance lock to synchronize unregistration. This implies that releasing of the "main" reference of the devlink instance moves from devlink_unregister() to devlink_free(). Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-01-06 14:33:58 +08:00
* devl_unregister - Unregister devlink instance
* @devlink: devlink
*/
devlink: remove the registration guarantee of references The objective of exposing the devlink instance locks to drivers was to let them use these locks to prevent user space from accessing the device before it's fully initialized. This is difficult because devlink_unregister() waits for all references to be released, meaning that devlink_unregister() can't itself be called under the instance lock. To avoid this issue devlink_register() was moved after subobject registration a while ago. Unfortunately the netdev paths get a hold of the devlink instances _before_ they are registered. Ideally netdev should wait for devlink init to finish (synchronizing on the instance lock). This can't work because we don't know if the instance will _ever_ be registered (in case of failures it may not). The other option of returning an error until devlink_register() is called is unappealing (user space would get a notification netdev exist but would have to wait arbitrary amount of time before accessing some of its attributes). Weaken the guarantees of the devlink references. Holding a reference will now only guarantee that the memory of the object is around. Another way of looking at it is that the reference now protects the object not its "registered" status. Use devlink instance lock to synchronize unregistration. This implies that releasing of the "main" reference of the devlink instance moves from devlink_unregister() to devlink_free(). Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-01-06 14:33:58 +08:00
void devl_unregister(struct devlink *devlink)
{
ASSERT_DEVLINK_REGISTERED(devlink);
devlink: remove the registration guarantee of references The objective of exposing the devlink instance locks to drivers was to let them use these locks to prevent user space from accessing the device before it's fully initialized. This is difficult because devlink_unregister() waits for all references to be released, meaning that devlink_unregister() can't itself be called under the instance lock. To avoid this issue devlink_register() was moved after subobject registration a while ago. Unfortunately the netdev paths get a hold of the devlink instances _before_ they are registered. Ideally netdev should wait for devlink init to finish (synchronizing on the instance lock). This can't work because we don't know if the instance will _ever_ be registered (in case of failures it may not). The other option of returning an error until devlink_register() is called is unappealing (user space would get a notification netdev exist but would have to wait arbitrary amount of time before accessing some of its attributes). Weaken the guarantees of the devlink references. Holding a reference will now only guarantee that the memory of the object is around. Another way of looking at it is that the reference now protects the object not its "registered" status. Use devlink instance lock to synchronize unregistration. This implies that releasing of the "main" reference of the devlink instance moves from devlink_unregister() to devlink_free(). Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-01-06 14:33:58 +08:00
devl_assert_locked(devlink);
devlink_notify_unregister(devlink);
xa_clear_mark(&devlinks, devlink->index, DEVLINK_REGISTERED);
devlink: remove the registration guarantee of references The objective of exposing the devlink instance locks to drivers was to let them use these locks to prevent user space from accessing the device before it's fully initialized. This is difficult because devlink_unregister() waits for all references to be released, meaning that devlink_unregister() can't itself be called under the instance lock. To avoid this issue devlink_register() was moved after subobject registration a while ago. Unfortunately the netdev paths get a hold of the devlink instances _before_ they are registered. Ideally netdev should wait for devlink init to finish (synchronizing on the instance lock). This can't work because we don't know if the instance will _ever_ be registered (in case of failures it may not). The other option of returning an error until devlink_register() is called is unappealing (user space would get a notification netdev exist but would have to wait arbitrary amount of time before accessing some of its attributes). Weaken the guarantees of the devlink references. Holding a reference will now only guarantee that the memory of the object is around. Another way of looking at it is that the reference now protects the object not its "registered" status. Use devlink instance lock to synchronize unregistration. This implies that releasing of the "main" reference of the devlink instance moves from devlink_unregister() to devlink_free(). Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-01-06 14:33:58 +08:00
}
EXPORT_SYMBOL_GPL(devl_unregister);
void devlink_unregister(struct devlink *devlink)
{
devl_lock(devlink);
devl_unregister(devlink);
devl_unlock(devlink);
}
EXPORT_SYMBOL_GPL(devlink_unregister);
/**
* devlink_alloc_ns - Allocate new devlink instance resources
* in specific namespace
*
* @ops: ops
* @priv_size: size of user private data
* @net: net namespace
* @dev: parent device
*
* Allocate new devlink instance resources, including devlink index
* and name.
*/
struct devlink *devlink_alloc_ns(const struct devlink_ops *ops,
size_t priv_size, struct net *net,
struct device *dev)
{
struct devlink *devlink;
static u32 last_id;
int ret;
WARN_ON(!ops || !dev);
if (!devlink_reload_actions_valid(ops))
return NULL;
devlink = kzalloc(sizeof(*devlink) + priv_size, GFP_KERNEL);
if (!devlink)
return NULL;
ret = xa_alloc_cyclic(&devlinks, &devlink->index, devlink, xa_limit_31b,
&last_id, GFP_KERNEL);
if (ret < 0)
goto err_xa_alloc;
devlink->dev = dev;
devlink->ops = ops;
xa_init_flags(&devlink->ports, XA_FLAGS_ALLOC);
xa_init_flags(&devlink->params, XA_FLAGS_ALLOC);
xa_init_flags(&devlink->snapshot_ids, XA_FLAGS_ALLOC);
write_pnet(&devlink->_net, net);
INIT_LIST_HEAD(&devlink->rate_list);
INIT_LIST_HEAD(&devlink->linecard_list);
INIT_LIST_HEAD(&devlink->sb_list);
INIT_LIST_HEAD_RCU(&devlink->dpipe_table_list);
INIT_LIST_HEAD(&devlink->resource_list);
INIT_LIST_HEAD(&devlink->region_list);
INIT_LIST_HEAD(&devlink->reporter_list);
INIT_LIST_HEAD(&devlink->trap_list);
INIT_LIST_HEAD(&devlink->trap_group_list);
INIT_LIST_HEAD(&devlink->trap_policer_list);
INIT_RCU_WORK(&devlink->rwork, devlink_release);
lockdep_register_key(&devlink->lock_key);
mutex_init(&devlink->lock);
lockdep_set_class(&devlink->lock, &devlink->lock_key);
refcount_set(&devlink->refcount, 1);
return devlink;
err_xa_alloc:
kfree(devlink);
return NULL;
}
EXPORT_SYMBOL_GPL(devlink_alloc_ns);
/**
* devlink_free - Free devlink instance resources
*
* @devlink: devlink
*/
void devlink_free(struct devlink *devlink)
{
ASSERT_DEVLINK_NOT_REGISTERED(devlink);
WARN_ON(!list_empty(&devlink->trap_policer_list));
WARN_ON(!list_empty(&devlink->trap_group_list));
WARN_ON(!list_empty(&devlink->trap_list));
WARN_ON(!list_empty(&devlink->reporter_list));
WARN_ON(!list_empty(&devlink->region_list));
WARN_ON(!list_empty(&devlink->resource_list));
WARN_ON(!list_empty(&devlink->dpipe_table_list));
WARN_ON(!list_empty(&devlink->sb_list));
WARN_ON(!list_empty(&devlink->rate_list));
WARN_ON(!list_empty(&devlink->linecard_list));
WARN_ON(!xa_empty(&devlink->ports));
xa_destroy(&devlink->snapshot_ids);
xa_destroy(&devlink->params);
xa_destroy(&devlink->ports);
xa_erase(&devlinks, devlink->index);
devlink: remove the registration guarantee of references The objective of exposing the devlink instance locks to drivers was to let them use these locks to prevent user space from accessing the device before it's fully initialized. This is difficult because devlink_unregister() waits for all references to be released, meaning that devlink_unregister() can't itself be called under the instance lock. To avoid this issue devlink_register() was moved after subobject registration a while ago. Unfortunately the netdev paths get a hold of the devlink instances _before_ they are registered. Ideally netdev should wait for devlink init to finish (synchronizing on the instance lock). This can't work because we don't know if the instance will _ever_ be registered (in case of failures it may not). The other option of returning an error until devlink_register() is called is unappealing (user space would get a notification netdev exist but would have to wait arbitrary amount of time before accessing some of its attributes). Weaken the guarantees of the devlink references. Holding a reference will now only guarantee that the memory of the object is around. Another way of looking at it is that the reference now protects the object not its "registered" status. Use devlink instance lock to synchronize unregistration. This implies that releasing of the "main" reference of the devlink instance moves from devlink_unregister() to devlink_free(). Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-01-06 14:33:58 +08:00
devlink_put(devlink);
}
EXPORT_SYMBOL_GPL(devlink_free);
static void __net_exit devlink_pernet_pre_exit(struct net *net)
{
struct devlink *devlink;
u32 actions_performed;
unsigned long index;
int err;
/* In case network namespace is getting destroyed, reload
* all devlink instances from this namespace into init_net.
*/
devlinks_xa_for_each_registered_get(net, index, devlink) {
devl_lock(devlink);
err = 0;
if (devl_is_registered(devlink))
err = devlink_reload(devlink, &init_net,
DEVLINK_RELOAD_ACTION_DRIVER_REINIT,
DEVLINK_RELOAD_LIMIT_UNSPEC,
&actions_performed, NULL);
devl_unlock(devlink);
devlink_put(devlink);
if (err && err != -EOPNOTSUPP)
pr_warn("Failed to reload devlink instance into init_net\n");
}
}
static struct pernet_operations devlink_pernet_ops __net_initdata = {
.pre_exit = devlink_pernet_pre_exit,
};
devlink: Fix crash with CONFIG_NET_NS=n '__net_initdata' becomes a no-op with CONFIG_NET_NS=y, but when this option is disabled it becomes '__initdata', which means the data can be freed after the initialization phase. This annotation is obviously incorrect for the devlink net device notifier block which is still registered after the initialization phase [1]. Fix this crash by removing the '__net_initdata' annotation. [1] general protection fault, probably for non-canonical address 0xcccccccccccccccc: 0000 [#1] PREEMPT SMP CPU: 3 PID: 117 Comm: (udev-worker) Not tainted 6.4.0-rc1-custom-gdf0acdc59b09 #64 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-1.fc37 04/01/2014 RIP: 0010:notifier_call_chain+0x58/0xc0 [...] Call Trace: <TASK> dev_set_mac_address+0x85/0x120 dev_set_mac_address_user+0x30/0x50 do_setlink+0x219/0x1270 rtnl_setlink+0xf7/0x1a0 rtnetlink_rcv_msg+0x142/0x390 netlink_rcv_skb+0x58/0x100 netlink_unicast+0x188/0x270 netlink_sendmsg+0x214/0x470 __sys_sendto+0x12f/0x1a0 __x64_sys_sendto+0x24/0x30 do_syscall_64+0x38/0x80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Fixes: e93c9378e33f ("devlink: change per-devlink netdev notifier to static one") Reported-by: Marek Szyprowski <m.szyprowski@samsung.com> Closes: https://lore.kernel.org/netdev/600ddf9e-589a-2aa0-7b69-a438f833ca10@samsung.com/ Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Link: https://lore.kernel.org/r/20230515162925.1144416-1-idosch@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-05-16 00:29:25 +08:00
static struct notifier_block devlink_port_netdevice_nb = {
devlink: change per-devlink netdev notifier to static one The commit 565b4824c39f ("devlink: change port event netdev notifier from per-net to global") changed original per-net notifier to be per-devlink instance. That fixed the issue of non-receiving events of netdev uninit if that moved to a different namespace. That worked fine in -net tree. However, later on when commit ee75f1fc44dd ("net/mlx5e: Create separate devlink instance for ethernet auxiliary device") and commit 72ed5d5624af ("net/mlx5: Suspend auxiliary devices only in case of PCI device suspend") were merged, a deadlock was introduced when removing a namespace with devlink instance with another nested instance. Here there is the bad flow example resulting in deadlock with mlx5: net_cleanup_work -> cleanup_net (takes down_read(&pernet_ops_rwsem) -> devlink_pernet_pre_exit() -> devlink_reload() -> mlx5_devlink_reload_down() -> mlx5_unload_one_devl_locked() -> mlx5_detach_device() -> del_adev() -> mlx5e_remove() -> mlx5e_destroy_devlink() -> devlink_free() -> unregister_netdevice_notifier() (takes down_write(&pernet_ops_rwsem) Steps to reproduce: $ modprobe mlx5_core $ ip netns add ns1 $ devlink dev reload pci/0000:08:00.0 netns ns1 $ ip netns del ns1 Resolve this by converting the notifier from per-devlink instance to a static one registered during init phase and leaving it registered forever. Use this notifier for all devlink port instances created later on. Note what a tree needs this fix only in case all of the cited fixes commits are present. Reported-by: Moshe Shemesh <moshe@nvidia.com> Fixes: 565b4824c39f ("devlink: change port event netdev notifier from per-net to global") Fixes: ee75f1fc44dd ("net/mlx5e: Create separate devlink instance for ethernet auxiliary device") Fixes: 72ed5d5624af ("net/mlx5: Suspend auxiliary devices only in case of PCI device suspend") Signed-off-by: Jiri Pirko <jiri@nvidia.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Link: https://lore.kernel.org/r/20230510144621.932017-1-jiri@resnulli.us Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-05-10 22:46:21 +08:00
.notifier_call = devlink_port_netdevice_event,
};
static int __init devlink_init(void)
{
int err;
err = genl_register_family(&devlink_nl_family);
if (err)
goto out;
err = register_pernet_subsys(&devlink_pernet_ops);
devlink: change per-devlink netdev notifier to static one The commit 565b4824c39f ("devlink: change port event netdev notifier from per-net to global") changed original per-net notifier to be per-devlink instance. That fixed the issue of non-receiving events of netdev uninit if that moved to a different namespace. That worked fine in -net tree. However, later on when commit ee75f1fc44dd ("net/mlx5e: Create separate devlink instance for ethernet auxiliary device") and commit 72ed5d5624af ("net/mlx5: Suspend auxiliary devices only in case of PCI device suspend") were merged, a deadlock was introduced when removing a namespace with devlink instance with another nested instance. Here there is the bad flow example resulting in deadlock with mlx5: net_cleanup_work -> cleanup_net (takes down_read(&pernet_ops_rwsem) -> devlink_pernet_pre_exit() -> devlink_reload() -> mlx5_devlink_reload_down() -> mlx5_unload_one_devl_locked() -> mlx5_detach_device() -> del_adev() -> mlx5e_remove() -> mlx5e_destroy_devlink() -> devlink_free() -> unregister_netdevice_notifier() (takes down_write(&pernet_ops_rwsem) Steps to reproduce: $ modprobe mlx5_core $ ip netns add ns1 $ devlink dev reload pci/0000:08:00.0 netns ns1 $ ip netns del ns1 Resolve this by converting the notifier from per-devlink instance to a static one registered during init phase and leaving it registered forever. Use this notifier for all devlink port instances created later on. Note what a tree needs this fix only in case all of the cited fixes commits are present. Reported-by: Moshe Shemesh <moshe@nvidia.com> Fixes: 565b4824c39f ("devlink: change port event netdev notifier from per-net to global") Fixes: ee75f1fc44dd ("net/mlx5e: Create separate devlink instance for ethernet auxiliary device") Fixes: 72ed5d5624af ("net/mlx5: Suspend auxiliary devices only in case of PCI device suspend") Signed-off-by: Jiri Pirko <jiri@nvidia.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Link: https://lore.kernel.org/r/20230510144621.932017-1-jiri@resnulli.us Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-05-10 22:46:21 +08:00
if (err)
goto out;
err = register_netdevice_notifier(&devlink_port_netdevice_nb);
out:
WARN_ON(err);
return err;
}
subsys_initcall(devlink_init);