On 24.10.2016 12:32, Vladimir Sementsov-Ogievskiy wrote: > 21.10.2016 22:58, Max Reitz пишет: >> On 21.10.2016 17:34, Vladimir Sementsov-Ogievskiy wrote: >>> 07.10.2016 22:44, Max Reitz пишет: >>>> On 30.09.2016 12:53, Vladimir Sementsov-Ogievskiy wrote: >>>>> This flag means that the bitmap is now in use by the software or >>>>> was not >>>>> successfully saved. In any way, with this flag set the bitmap data >>>>> must >>>>> be considered inconsistent and should not be loaded. >>>>> >>>>> With current implementation this flag is never set, as we just remove >>>>> bitmaps from the image after loading. But it defined in qcow2 spec and >>>>> must be handled. Also, it can be used in future, if async schemes of >>>>> bitmap loading/saving are implemented. >>>>> >>>>> We also remove in-use bitmaps from the image on open. >>>>> >>>>> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com> >>>>> --- >>>>> block/qcow2-bitmap.c | 17 ++++++++++++++++- >>>>> 1 file changed, 16 insertions(+), 1 deletion(-) >>>> Don't you want to make use of this flag? It would appear useful to >>>> me if >>>> you just marked autoload bitmaps as in_use instead of deleting them >>>> from >>>> the image when it's opened and then overwrite them when the image is >>>> closed. >>> And what is the use of it? >> You don't need to free any bitmaps when opening the file, and you don't >> need to allocate any new bitmap space when closing it. > > As bitmaps are sparce in file, I need to allocate new space when > closing. Or free it...
May happen. But not necessarily, and it will probably still save time as you can reuse existing allocations and don't have to free everything. Max
signature.asc
Description: OpenPGP digital signature
