Re: [Qemu-devel] [PATCH 22/24] block/dirty-bitmap: deep release dirty bitmaps

[Max Reitz]

On 01.02.2017 00:00, Max Reitz wrote:
> On 31.01.2017 17:03, Vladimir Sementsov-Ogievskiy wrote:

[...]

>> I've started to rewrite it in that way and it seems like deep almost
>> always will be false. What about just move call to
>> bs->drv->bdrv_remove_persistent_dirty_bitmap() directly to
>> qmp_block_dirty_bitmap_remove and add parameter
>> 'remove_persistent' (or 'remove_from_storage', to make it maximum
>> descriptive) only to this qmp command?
> 
> Or you could add an explicit bdrv_remove_persistent_dirty_bitmap() which
> just wraps the bs->drv function.
> 
>> Or even without that parameter, as leaving inconsistent version of
>> bitmap in the storage doesn't seem useful.
> 
> Hm, right, the bitmap will be automatically removed from the image once
> it's closed, right?

[No, it won't.]

But you're right, if a persistent bitmap is completely removed by the
user, it should probably be always removed from the image file, too.

The only use I could think of for dropping a bitmap from memory but
wanting to keep it in the file is for keeping it at a certain state. It
would make more sense to allow the user to disable a bitmap to achieve
this, though.

We don't have a block-dirty-bitmap-disable command yet, though, but I
guess it shouldn't be too hard to add...?

(Anyway, it's something that's out of scope for this series, I think.)

Max

signature.asc
Description: OpenPGP digital signature