> -----Original Message----- > From: Coly Li [mailto:i@xxxxxxx] > Sent: Tuesday, September 26, 2017 4:09 PM > To: Michael Lyle; Coly Li > Cc: linux-bcache@xxxxxxxxxxxxxxx; linux-block@xxxxxxxxxxxxxxx; > axboe@xxxxxxxxx; Eric Wheeler; Byungchul Park; Kent Overstreet > Subject: Re: [PATCH 04/12] bcache: Don't reinvent the wheel but use existing > llist API > > On 2017/9/26 下午12:38, Michael Lyle wrote: > > I believe this introduces a critical bug. > > > > cl->list is used to link together the llists for both things waiting, > > and for things that are being woken. > > > > If a closure that is woken decides to wait again, it will corrupt the > > llist that __closure_wake_up is using. > > > > The previous iteration structure gets the next element of the list > > before waking and is therefore safe. > > > > Hi Mike, > > Good catch! I see llist_del_all() but forget cl->list can be modified in > closure_wait(). Yes there is potential chance to mislead > llist_for_each_entry() to iterate wrong list. > llist_for_each_entry_safe() should be used here. I will send a fix to > Jens, hope to catch up 4.14 still. I see. You have a plan to do it. Please fix it. Thank you. > Thanks! > -- > Coly Li
