Re: [Qemu-devel] [PATCH] block: Make op blocker recursive

[Benoît Canet]

The Monday 23 Jun 2014 à 12:32:30 (+0800), Fam Zheng wrote :
> On Sat, 06/21 17:40, Benoît Canet wrote:
> > The Saturday 21 Jun 2014 à 17:39:11 (+0200), Benoît Canet wrote :
> > > We still have the issue of unlocking the bottom BDS when a subtree is 
> > > detached
> > > from the graphs by a swap. (It does happen in my drive-mirror arbitrary 
> > > node
> > > replacement series).
> > > 
> > > From my understanding the unlocking of the root BDS is done by 
> > > drive_mirror_complete
> > > while the mirror code tries to unref the orphaned subtree _before_ 
> > > drive_mirror_complete
> > > is called.
> > 
> > One fixe to my sentence:
> > s/drive_mirror_complete/block_job_complete/
> > 
> > 
> > > 
> > > So the bottom BDS would be unrefed before being unlocked.
> 
> I don't see a problem with that, we can do the unlock before unref the node if
> we want.

My concern is that mirror.c does the unref and don't own the Blocker by itself.
The blocker is owned by the blockjob so it's difficult for mirror.c to do the 
unblock.

> 
> Fam