cbaaa6326b
rtnl_newlink() needs to hold 3 per-netns RTNL: 2 for a new device and 1 for its peer. We will add rtnl_nets_lock() later, which performs the nested locking based on struct rtnl_nets, which has an array of struct net pointers. rtnl_nets_add() adds a net pointer to the array and sorts it so that rtnl_nets_lock() can simply acquire per-netns RTNL from array[0] to [2]. Before calling rtnl_nets_add(), get_net() must be called for the net, and rtnl_nets_destroy() will call put_net() for each. Let's apply the helpers to rtnl_newlink(). When CONFIG_DEBUG_NET_SMALL_RTNL is disabled, we do not call rtnl_net_lock() thus do not care about the array order, so rtnl_net_cmp_locks() returns -1 so that the loop in rtnl_nets_add() can be optimised to NOP. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org> Link: https://patch.msgid.link/20241108004823.29419-5-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.