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

Liu Yuan namei.unix at gmail.com
Wed May 8 05:16:19 CEST 2013


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.

Thanks,
Yuan



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