Re: [Qemu-block] [PATCH v7 07/16] block/dirty-bitmap: add bdrv_dirty_bitmap_release_successor

[Vladimir Sementsov-Ogievskiy]

10.07.2017 19:30, Vladimir Sementsov-Ogievskiy wrote:
> To just release successor and unfreeze bitmap without any additional
> work.
>
> Signed-off-by: Vladimir Sementsov-Ogievskiy <address@hidden>
> Signed-off-by: Denis V. Lunev <address@hidden>
> ---
>   block/dirty-bitmap.c         | 13 +++++++++++++
>   include/block/dirty-bitmap.h |  2 ++
>   2 files changed, 15 insertions(+)
>
> diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
> index 7b598c36bf..b5678d2d25 100644
> --- a/block/dirty-bitmap.c
> +++ b/block/dirty-bitmap.c
> @@ -303,6 +303,19 @@ BdrvDirtyBitmap 
> *bdrv_reclaim_dirty_bitmap(BlockDriverState *bs,
>       return parent;
>   }
>   
> +/* Called with BQL taken. */
> +void bdrv_dirty_bitmap_release_successor(BlockDriverState *bs,
> +                                         BdrvDirtyBitmap *parent)
> +{
> +    qemu_mutex_lock(parent->mutex);
> +
> +    if (parent->successor) {
> +        bdrv_release_dirty_bitmap(bs, parent->successor);

this will try to lock same mutex and deadlock.

> +        parent->successor = NULL;
> +    }
> +
> +    qemu_mutex_unlock(parent->mutex);
> +}
>   /**
>    * Truncates _all_ bitmaps attached to a BDS.
>    * Called with BQL taken.
> diff --git a/include/block/dirty-bitmap.h b/include/block/dirty-bitmap.h
> index d00a7a4b7c..fa2f670050 100644
> --- a/include/block/dirty-bitmap.h
> +++ b/include/block/dirty-bitmap.h
> @@ -20,6 +20,8 @@ BdrvDirtyBitmap *bdrv_dirty_bitmap_abdicate(BlockDriverState 
> *bs,
>   BdrvDirtyBitmap *bdrv_reclaim_dirty_bitmap(BlockDriverState *bs,
>                                              BdrvDirtyBitmap *bitmap,
>                                              Error **errp);
> +void bdrv_dirty_bitmap_release_successor(BlockDriverState *bs,
> +                                         BdrvDirtyBitmap *bitmap);
>   void bdrv_dirty_bitmap_enable_successor(BdrvDirtyBitmap *bitmap);
>   BdrvDirtyBitmap *bdrv_find_dirty_bitmap(BlockDriverState *bs,
>                                           const char *name);


--
Best regards,
Vladimir