On Mon, Sep 8, 2025 at 1:52 AM Yu Kuai <yukuai1@xxxxxxxxxxxxxxx> wrote: > > Hi, > > 在 2025/09/06 17:16, Eric Dumazet 写道: > > On Fri, Sep 5, 2025 at 1:03 PM Eric Dumazet <edumazet@xxxxxxxxxx> wrote: > >> > >> On Fri, Sep 5, 2025 at 1:00 PM syzbot > >> <syzbot+e1cd6bd8493060bd701d@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > > > Note to NBD maintainers : I held about 20 syzbot reports all pointing > > to NBD accepting various sockets, I can release them if needed, if you prefer > > to triage them. > > > I'm not NBD maintainer, just trying to understand the deadlock first. > > Is this deadlock only possible for some sepecific socket types? Take > a look at the report here: > > Usually issue IO will require the order: > > q_usage_counter -> cmd lock -> tx lock -> sk lock > I have not seen the deadlock being reported with normal TCP sockets. NBD sets sk->sk_allocation to GFP_NOIO | __GFP_MEMALLOC; from __sock_xmit(), and TCP seems to respect this.
