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Re: [Qemu-block] [PATCH 2/5] block: Remove dirty bitmaps from bdrv_move_
From: |
Eric Blake |
Subject: |
Re: [Qemu-block] [PATCH 2/5] block: Remove dirty bitmaps from bdrv_move_feature_fields() |
Date: |
Mon, 14 Mar 2016 09:55:00 -0600 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 |
On 03/14/2016 09:44 AM, Kevin Wolf wrote:
> This patch changes dirty bitmaps from following a BlockBackend in graph
> changes to sticking with the node they were created at. For the full
> discussion, read the following mailing list thread:
>
> [Qemu-block] block: Dirty bitmaps and COR in bdrv_move_feature_fields()
> https://lists.nongnu.org/archive/html/qemu-block/2016-02/msg00745.html
>
> In summary, the justification for this change is:
[snip nice list]
>
> At the end of the day it seems to be very clear that it was a mistake to
> include dirty bitmaps in bdrv_move_feature_fields(). The functionality
> of moving bitmaps and/or attaching them to a BlockBackend instead will
> probably be needed, but it should be done with a new explicit QMP
> command or option.
>
> Signed-off-by: Kevin Wolf <address@hidden>
> ---
> block.c | 3 ---
> 1 file changed, 3 deletions(-)
Reviewed-by: Eric Blake <address@hidden>
[Always interesting when a patch is way shorter than the justification
for why we need the patch]
>
> diff --git a/block.c b/block.c
> index a75c4b3..698e2c7 100644
> --- a/block.c
> +++ b/block.c
> @@ -2284,9 +2284,6 @@ static void bdrv_move_feature_fields(BlockDriverState
> *bs_dest,
>
> /* dev info */
> bs_dest->enable_write_cache = bs_src->enable_write_cache;
> -
> - /* dirty bitmap */
> - bs_dest->dirty_bitmaps = bs_src->dirty_bitmaps;
> }
>
> static void change_parent_backing_link(BlockDriverState *from,
>
--
Eric Blake eblake redhat com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
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- [Qemu-block] [PATCH 0/5] block: API changes for 2.6, Kevin Wolf, 2016/03/14
- [Qemu-block] [PATCH 2/5] block: Remove dirty bitmaps from bdrv_move_feature_fields(), Kevin Wolf, 2016/03/14
- Re: [Qemu-block] [PATCH 2/5] block: Remove dirty bitmaps from bdrv_move_feature_fields(),
Eric Blake <=
- [Qemu-block] [PATCH 1/5] block: Remove copy-on-read from bdrv_move_feature_fields(), Kevin Wolf, 2016/03/14
- [Qemu-block] [PATCH 4/5] block: Make backing files always writeback, Kevin Wolf, 2016/03/14
- [Qemu-block] [PATCH 3/5] block: Remove cache.writeback from blockdev-add, Kevin Wolf, 2016/03/14
- [Qemu-block] [PATCH 5/5] block: Reject writethrough mode except at the root, Kevin Wolf, 2016/03/14
- Re: [Qemu-block] [PATCH 0/5] block: API changes for 2.6, Kevin Wolf, 2016/03/18