Re: [Qemu-devel] [PATCH for-4.1] util/hbitmap: update orig_size on truncate

[Max Reitz <mreitz@redhat.com>]

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On 05.08.19 14:01, Vladimir Sementsov-Ogievskiy wrote:
> Without this, hbitmap_next_zero and hbitmap_next_dirty_area are broken
> after truncate. So, orig_size is broken since it's introduction in
> 76d570dc495c56bb.
> 
> Fixes: 76d570dc495c56bb
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
> ---
> 
> Hi!
> 
> Here is one more hbitmap bug I noticed. It's my fault, I'm sorry :(
> Broken in 4.0, but if we are already going to fix in 4.1 some things
> around it, it's a small meaningful addition.

Hm. :-/

> Users of broken API are incremental backup, sync mirror (but it may not
> be broken, if truncates not allowed during mirror, are they?),

It doesn’t appear that way (we don’t share BLK_PERM_RESIZE).

> bitmap export through NBD.

I suppose that counts as block-y enough for me to take it.  Well, I’d
still like a test case to see the impact...  I’ll see whether I can come
up with something.

>  util/hbitmap.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)

Reviewed-by: Max Reitz <mreitz@redhat.com>


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