Re: [Qemu-devel] [PATCH v16 11/22] block: introduce persistent dirty bitmaps

[Max Reitz <mreitz@redhat.com>]

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On 25.02.2017 18:07, Vladimir Sementsov-Ogievskiy wrote:
> New field BdrvDirtyBitmap.persistent means, that bitmap should be saved
> on bdrv_close, using format driver.

Somehow this sentence stays valid, but it has a much different meaning
now. bdrv_close() no longer directly takes care of saving bitmaps but
its completely up to the format driver. In any case, this patch has no
longer anything to do with that, so I think this statement should be
changed.

Max

>                                     Format driver should maintain bitmap
> storing.
> 
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
> ---
>  block/dirty-bitmap.c         | 26 ++++++++++++++++++++++++++
>  block/qcow2-bitmap.c         |  1 +
>  include/block/dirty-bitmap.h |  6 ++++++
>  3 files changed, 33 insertions(+)
> 
> diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
> index a9dfce8d00..d2fbf55964 100644
> --- a/block/dirty-bitmap.c
> +++ b/block/dirty-bitmap.c
> @@ -44,6 +44,7 @@ struct BdrvDirtyBitmap {
>      int64_t size;               /* Size of the bitmap (Number of sectors) */
>      bool disabled;              /* Bitmap is read-only */
>      int active_iterators;       /* How many iterators are active */
> +    bool persistent;            /* bitmap must be saved to owner disk image */
>      bool autoload;              /* For persistent bitmaps: bitmap must be
>                                     autoloaded on image opening */
>      QLIST_ENTRY(BdrvDirtyBitmap) list;
> @@ -72,6 +73,7 @@ void bdrv_dirty_bitmap_make_anon(BdrvDirtyBitmap *bitmap)
>      assert(!bdrv_dirty_bitmap_frozen(bitmap));
>      g_free(bitmap->name);
>      bitmap->name = NULL;
> +    bitmap->persistent = false;
>      bitmap->autoload = false;
>  }
>  
> @@ -241,6 +243,8 @@ BdrvDirtyBitmap *bdrv_dirty_bitmap_abdicate(BlockDriverState *bs,
>      bitmap->name = NULL;
>      successor->name = name;
>      bitmap->successor = NULL;
> +    successor->persistent = bitmap->persistent;
> +    bitmap->persistent = false;
>      successor->autoload = bitmap->autoload;
>      bitmap->autoload = false;
>      bdrv_release_dirty_bitmap(bs, bitmap);
> @@ -555,3 +559,25 @@ bool bdrv_dirty_bitmap_get_autoload(const BdrvDirtyBitmap *bitmap)
>  {
>      return bitmap->autoload;
>  }
> +
> +void bdrv_dirty_bitmap_set_persistance(BdrvDirtyBitmap *bitmap, bool persistent)
> +{
> +    bitmap->persistent = persistent;
> +}
> +
> +bool bdrv_dirty_bitmap_get_persistance(BdrvDirtyBitmap *bitmap)
> +{
> +    return bitmap->persistent;
> +}
> +
> +bool bdrv_has_persistent_bitmaps(BlockDriverState *bs)
> +{
> +    BdrvDirtyBitmap *bm;
> +    QLIST_FOREACH(bm, &bs->dirty_bitmaps, list) {
> +        if (bm->persistent) {
> +            return true;
> +        }
> +    }
> +
> +    return false;
> +}
> diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c
> index 6b1a2c9c67..ba72b7d2ac 100644
> --- a/block/qcow2-bitmap.c
> +++ b/block/qcow2-bitmap.c
> @@ -780,6 +780,7 @@ void qcow2_load_autoloading_dirty_bitmaps(BlockDriverState *bs, Error **errp)
>                  goto fail;
>              }
>  
> +            bdrv_dirty_bitmap_set_persistance(bitmap, true);
>              bdrv_dirty_bitmap_set_autoload(bitmap, true);
>              bm->flags |= BME_FLAG_IN_USE;
>              created_dirty_bitmaps =
> diff --git a/include/block/dirty-bitmap.h b/include/block/dirty-bitmap.h
> index 45a389a20a..8dbd16b040 100644
> --- a/include/block/dirty-bitmap.h
> +++ b/include/block/dirty-bitmap.h
> @@ -77,4 +77,10 @@ void bdrv_dirty_bitmap_deserialize_finish(BdrvDirtyBitmap *bitmap);
>  
>  void bdrv_dirty_bitmap_set_autoload(BdrvDirtyBitmap *bitmap, bool autoload);
>  bool bdrv_dirty_bitmap_get_autoload(const BdrvDirtyBitmap *bitmap);
> +void bdrv_dirty_bitmap_set_persistance(BdrvDirtyBitmap *bitmap,
> +                                                bool persistent);
> +bool bdrv_dirty_bitmap_get_persistance(BdrvDirtyBitmap *bitmap);
> +
> +bool bdrv_has_persistent_bitmaps(BlockDriverState *bs);
> +
>  #endif
> 



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