linux/net/devlink/core.c, branch v6.3

devlink: convert param list to xarray

2023-02-13T09:49:14Z

Loose the linked list for params and use xarray instead. Note that this is required to be eventually possible to call devl_param_driverinit_value_get() without holding instance lock. Signed-off-by: Jiri Pirko Reviewed-by: Simon Horman Acked-by: Jakub Kicinski Reviewed-by: Jacob Keller Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2023-02-09T20:25:40Z

net/devlink/leftover.c / net/core/devlink.c: 565b4824c39f ("devlink: change port event netdev notifier from per-net to global") f05bd8ebeb69 ("devlink: move code to a dedicated directory") 687125b5799c ("devlink: split out core code") https://lore.kernel.org/all/20230208094657.379f2b1a@canb.auug.org.au/ Signed-off-by: Jakub Kicinski

devlink: remove devlink features

2023-01-30T08:37:46Z

Devlink features were introduced to disallow devlink reload calls of userspace before the devlink was fully initialized. The reason for this workaround was the fact that devlink reload was originally called without devlink instance lock held. However, with recent changes that converted devlink reload to be performed under devlink instance lock, this is redundant so remove devlink features entirely. Note that mlx5 used this to enable devlink reload conditionally only when device didn't act as multi port slave. Move the multi port check into mlx5_devlink_reload_down() callback alongside with the other checks preventing the device from reload in certain states. Signed-off-by: Jiri Pirko Reviewed-by: Jacob Keller Signed-off-by: David S. Miller

devlink: remove reporters_lock

2023-01-20T03:08:37Z

Similar to other devlink objects, rely on devlink instance lock and remove object specific reporters_lock. Signed-off-by: Jiri Pirko Reviewed-by: Jacob Keller Signed-off-by: Jakub Kicinski

devlink: remove linecards lock

2023-01-20T03:08:37Z

Similar to other devlink objects, convert the linecards list to be protected by devlink instance lock. Alongside with that rename the create/destroy() functions to devl_* to indicate the devlink instance lock needs to be held while calling them. Signed-off-by: Jiri Pirko Reviewed-by: Ido Schimmel Reviewed-by: Jacob Keller Signed-off-by: Jakub Kicinski

devlink: keep the instance mutex alive until references are gone

2023-01-12T04:49:32Z

The reference needs to keep the instance memory around, but also the instance lock must remain valid. Users will take the lock, check registration status and release the lock. mutex_destroy() etc. belong in the same place as the freeing of the memory. Unfortunately lockdep_unregister_key() sleeps so we need to switch the an rcu_work. Note that the problem is a bit hard to repro, because devlink_pernet_pre_exit() iterates over registered instances. AFAIU the instances must get devlink_free()d concurrently with the namespace getting deleted for the problem to occur. Reported-by: syzbot+d94d214ea473e218fc89@syzkaller.appspotmail.com Reported-by: syzbot+9f0dd863b87113935acf@syzkaller.appspotmail.com Fixes: 9053637e0da7 ("devlink: remove the registration guarantee of references") Reviewed-by: Jiri Pirko Reviewed-by: Jacob Keller Link: https://lore.kernel.org/r/20230111042908.988199-1-kuba@kernel.org Signed-off-by: Jakub Kicinski

devlink: don't require setting features before registration

2023-01-06T12:56:19Z

Requiring devlink_set_features() to be run before devlink is registered is overzealous. devlink_set_features() itself is a leftover from old workarounds which were trying to prevent initiating reload before probe was complete. Signed-off-by: Jakub Kicinski Reviewed-by: Jiri Pirko Signed-off-by: David S. Miller

devlink: remove the registration guarantee of references

2023-01-06T12:56:19Z

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 Signed-off-by: Jakub Kicinski Reviewed-by: Jiri Pirko Signed-off-by: David S. Miller

devlink: always check if the devlink instance is registered

2023-01-06T12:56:19Z

Always check under the instance lock whether the devlink instance is still / already registered. This is a no-op for the most part, as the unregistration path currently waits for all references. On the init path, however, we may temporarily open up a race with netdev code, if netdevs are registered before the devlink instance. This is temporary, the next change fixes it, and this commit has been split out for the ease of review. Note that in case of iterating over sub-objects which have their own lock (regions and line cards) we assume an implicit dependency between those objects existing and devlink unregistration. Signed-off-by: Jakub Kicinski Reviewed-by: Jiri Pirko Signed-off-by: David S. Miller

devlink: update the code in netns move to latest helpers

2023-01-06T12:56:18Z

devlink_pernet_pre_exit() is the only obvious place which takes the instance lock without using the devl_ helpers. Update the code and move the error print after releasing the reference (having unlock and put together feels slightly idiomatic). Reviewed-by: Jiri Pirko Signed-off-by: Jakub Kicinski Signed-off-by: David S. Miller