From: David S. Miller Date: Mon, 1 Nov 2021 13:26:07 +0000 (+0000) Subject: Merge branch 'devlink-locking' X-Git-Tag: v5.16-rc1~159^2~10 X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=1adc58ea2330cd014fde8a254480441e10ee280d;p=tomoyo%2Ftomoyo-test1.git Merge branch 'devlink-locking' Jakub Kicinski says: ==================== improve ethtool/rtnl vs devlink locking During ethtool netlink development we decided to move some of the commmands to devlink. Since we don't want drivers to implement both devlink and ethtool version of the commands ethtool ioctl falls back to calling devlink. Unfortunately devlink locks must be taken before rtnl_lock. This results in a questionable dev_hold() / rtnl_unlock() / devlink / rtnl_lock() / dev_put() pattern. This method "works" but it working depends on drivers in question not doing much in ethtool_ops->begin / complete, and on the netdev not having needs_free_netdev set. Since commit 437ebfd90a25 ("devlink: Count struct devlink consumers") we can hold a reference on a devlink instance and prevent it from going away (sort of like netdev with dev_hold()). We can use this to create a more natural reference nesting where we get a ref on the devlink instance and make the devlink call entirely outside of the rtnl_lock section. ==================== Signed-off-by: David S. Miller --- 1adc58ea2330cd014fde8a254480441e10ee280d