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From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
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Date: Thu, 13 Oct 2016 19:48:25 +0300
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Subject: Re: [Qemu-devel] [PATCH 11/22] qcow2-bitmap: add
 qcow2_store_persistent_bitmaps()
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To: Max Reitz <mreitz@redhat.com>, qemu-block@nongnu.org, qemu-devel@nongnu.org
Cc: kwolf@redhat.com, armbru@redhat.com, eblake@redhat.com, jsnow@redhat.com, famz@redhat.com, den@openvz.org, stefanha@redhat.com, pbonzini@redhat.com

On 07.10.2016 22:24, Max Reitz wrote:
> On 30.09.2016 12:53, Vladimir Sementsov-Ogievskiy wrote:
>> Realize block bitmap stroing interface, to allow qcow2 images store

[snip]

>> +        uint64_t end = MIN(bm_size, sector + dsc);
>> +        uint64_t write_size =
>> +            bdrv_dirty_bitmap_serialization_size(bitmap, sector, end - sector);
>> +
>> +        int64_t off = qcow2_alloc_clusters(bs, cl_size);
>> +        if (off < 0) {
>> +            ret = off;
>> +            goto finish;
>> +        }
>> +        bitmap_table[cluster] = off;
>> +
>> +        bdrv_dirty_bitmap_serialize_part(bitmap, buf, sector, end);
> s/end/end - sector/?

o_0 terrible mistake, thank you.

>
>> +        if (write_size < cl_size) {
>> +            memset(buf + write_size, 0, cl_size - write_size);
>> +        }
>> +
> I guess there should be a metadata overlap check here.

What is the general rule of checking it? Should I check it before all my 
extension related writes?


-- 
Best regards,
Vladimir