On 12/21/21 9:03 AM, Eric Dumazet wrote: > On Tue, Dec 21, 2021 at 7:25 AM Jens Axboe <axboe@xxxxxxxxx> wrote: >> >> On 12/21/21 3:44 AM, Eric Dumazet wrote: >>> On Tue, Dec 21, 2021 at 1:52 AM syzbot >>> <syzbot+8836466a79f4175961b0@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: >>>> >>>> syzbot has bisected this issue to: >>>> >>>> commit e4b8954074f6d0db01c8c97d338a67f9389c042f >>>> Author: Eric Dumazet <edumazet@xxxxxxxxxx> >>>> Date: Tue Dec 7 01:30:37 2021 +0000 >>>> >>>> netlink: add net device refcount tracker to struct ethnl_req_info >>>> >>> >>> Unfortunately this commit will be in the way of many bisections. >>> >>> Real bug was added in >>> >>> commit 5fc11eebb4a98df5324a4de369bb5ab7f0007ff7 >>> Author: Christoph Hellwig <hch@xxxxxx> >>> Date: Thu Dec 9 07:31:29 2021 +0100 >>> >>> block: open code create_task_io_context in set_task_ioprio >>> >>> The flow in set_task_ioprio can be simplified by simply open coding >>> create_task_io_context, which removes a refcount roundtrip on the I/O >>> context. >>> >>> Signed-off-by: Christoph Hellwig <hch@xxxxxx> >>> Reviewed-by: Jan Kara <jack@xxxxxxx> >>> Link: https://lore.kernel.org/r/20211209063131.18537-10-hch@xxxxxx >>> Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> >> >> There are only really 5 patches in between the broken commit and the one >> that fixes it, and it only affects things trying to set the ioprio with >> a dead task. Is this a huge issue? I don't see why this would cause a >> lot of bisection headaches. >> > > I was saying that my commit was polluting syzbot bisection, this is a > distraction in this report. > (Or if you prefer, please ignore syzbot bisection) Ah got it, yes makes sense. > linux-next has still this bug in set_task_ioprio() linux-next often trails by a few days, once it catches up hopefully this will be behind us. -- Jens Axboe
