On Wed, 11 Sep 2013 09:40:08 +0200 Jack Wang <xjtuwjp@xxxxxxxxx> wrote: > On 09/11/2013 01:54 AM, NeilBrown wrote: > > On Tue, 10 Sep 2013 13:09:05 +0200 Jack Wang <jinpu.wang@xxxxxxxxxxxxxxxx> > > wrote: > > > >> snip > >> > >> Hi Neil, > >> > >> I notice you send out pull request for md update, which include fix for > >> this bug. > >> > >> I think we'd better include the fix to stable tree at least from 3.4 > >> above, what do you think? > > > > I don't think it is a situation that is at all like to occur in normal usage, > > so it doesn't seem justified for -stable. > > > > Do you disagree? Did you ever experience the deadlock in normal usage or > > only in artificial situations? > > Yes, we do see this BUG in our production environment, so I think it's > good to include it in stable tree. > I was hoping you would explain how.... Maybe I'm misunderstanding, but as I see it the deadlock can only occur if you run "mdadm --stop" while some other process has the block device open and is writing to it. That seems like a dumb thing to do and my suggest would be to not do it. Is there a good reason why you try to stop the array while it is being written to. Would it make sense for the process to open the block device with O_EXCL. This would encourage exclusive access, and would also prevent the deadlock from happening. NeilBrown
Attachment:
signature.asc
Description: PGP signature
