[sheepdog] [PATCH v3 3/3] journal: new journal flag JF_DELETE_OBJ for deleting object

[Hitoshi Mitake]

At Wed, 08 May 2013 11:16:19 +0800,
Liu Yuan wrote:
> 
> On 05/08/2013 12:06 AM, Hitoshi Mitake wrote:
> >> > On 05/06/2013 10:15 PM, Hitoshi Mitake wrote:
> >>> > > Ah, I see. But the preallocated objects would consume disk
> >>> > > space. Removing them physically would be benefitical for thin
> >>> > > provisioning, I think. How do you think?
> >> > 
> >> > This is just the very unusual case and even if happens, only one extra
> >> > object is created, no?
> > I'm not sure about that. A number of removed objects would not be
> > 1. The number would depend on a way of using disks of guest OSes. How
> > do you think?
> > 
> >> > By the way, if we don't log the delete operation,
> >> > the 'discard command' doesn't return to the guest. So after restarting,
> >> > the guest will see the file is still there because inode isn't updated
> >> > successfully yet. Then people can re-delete the file, no?
> > Do you mean a failure during discard command? If so, I agree with your
> > opinion. But failures _after_ discard commands would cause problems
> > when the journaling mechanism is enabled.
> 
> Okay, please rebase the patch onto the master.

OK, I'll send v2 later.

Thanks,
Hitoshi