Hi cong, we increase the socket inuse in sk_allock ?
On Tue, Nov 14, 2017 at 1:58 PM, Cong Wang <xiyou.wangc...@gmail.com> wrote: > On Mon, Nov 13, 2017 at 7:23 PM, 张军伟(基础平台部) > <zhangjunweimar...@didichuxing.com> wrote: >> >>> On 14 Nov 2017, at 10:09, Cong Wang <xiyou.wangc...@gmail.com> wrote: >>> >>> On Mon, Nov 13, 2017 at 4:36 AM, Tonghao Zhang <xiangxia.m....@gmail.com> >>> wrote: >>>> From: Tonghao Zhang <xiangxia.m....@gmail.com> >>>> >>>> This patch add a member in struct netns_core. and this is >>>> a counter for socket_inuse in the _net_ namespace. The patch >>>> will add/sub counter in the sock_alloc or sock_release. In >>>> the sock_alloc, the private data of inode saves the special >>>> _net_. When releasing it, we can access the special _net_ and >>>> dec the counter of socket in that namespace. >>>> >>>> By the way, we dont use the 'current->nsproxy->net_ns' in the >>>> sock_release. In one case，when one task exits, the 'do_exit' >>>> may set the current->nsproxy NULL, and then call the sock_release. >>>> Use the private data of inode, saving few bytes. >>> >>> Why do you need to hold netns refcnt for socket? sock already holds >>> it, so you can just access it by sock_net(sock->sk) ? >> I think you suggestion is >> replace get_net(net) ===> with sock_net(sock->sk) > > Not literally, but essentially yes. > > >> >> If thus, I think it could not work. >> Because sock->sk is assigned after sock_alloc. >> What we change is done in sock_alloc. > > You don't have to do it in sock_alloc(). > > >> By the way, sock->sk may has been released(NULL) in sock_release. > > My point is since sock is always paired with a sk and sk already > holds refcnt, you don't need to hold it again, it looks unnecessary.
