We will convert ioctl(SIOCGARP) to RCU, and then we need to copy
dev->name which is currently protected by rtnl_lock().
This patch does the following:
1) Add seqlock netdev_rename_lock to protect dev->name
2) Add netdev_copy_name() that copies dev->name to buffer
under netdev_rename_lock
3) Use netdev_copy_name() in netdev_get_name() and drop
devnet_rename_sem
Suggested-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/netdev/CANn89iJEWs7AYSJqGCUABeVqOCTkErponfZdT5kV-iD=-SajnQ@mail.gmail.com/
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20240430015813.71143-7-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
0840556e5a