On Sat, Apr 14, 2018 at 5:26 PM, Tetsuo Handa <penguin-ker...@i-love.sakura.ne.jp> wrote: > OK. The patch was sent to linux.git as commit 1e047eaab3bb5564. > > #syz fix: block/loop: fix deadlock after loop_set_status > > Dmitry Vyukov <dvyu...@google.com>" wrote: >> On Tue, Apr 10, 2018 at 3:04 PM, Tetsuo Handa >> <penguin-ker...@i-love.sakura.ne.jp> wrote: >> > Dmitry Vyukov wrote: >> >> On Tue, Apr 10, 2018 at 12:55 PM, Tetsuo Handa >> >> <penguin-ker...@i-love.sakura.ne.jp> wrote: >> >> > Hello. >> >> > >> >> > Since syzbot is reporting so many hung up bug which involves /dev/loopX >> >> > , >> >> > is it possible to "temporarily" apply below patch for testing under >> >> > syzbot >> >> >> >> Unfortunately it's not possible, for full explanation please see: >> >> https://github.com/google/syzkaller/blob/master/docs/syzbot.md#no-custom-patches >> >> >> > >> > I mean, sending custom patch to linux.git for -rc and revert the custom >> > patch >> > before -final is released. It won't take so much period until we get the >> > result. >> >> Ah, I see, then I guess it wasn't a question to me. >> > I noticed that there already is the lockdep report at > > possible deadlock in blkdev_reread_part > > https://syzkaller.appspot.com/bug?id=bf154052f0eea4bc7712499e4569505907d15889 > > entry, and no patch is proposed yet: > > > https://groups.google.com/forum/#!msg/syzkaller-bugs/2Rw8-OM6IbM/SI4DyK-1AQAJ
If it's lock inversion, I wonder why there were no lockdep report before "task hung" report... Various assorted "task hung" reports seems to be plague for syzbot at the moment. Lockdep reports should be way more actionable based solely on the inversion report.