14.02.2019 2:36, John Snow wrote:
> Add an inconsistent bit to dirty-bitmaps that allows us to report a bitmap as
> persistent but potentially inconsistent, i.e. if we find bitmaps on a qcow2
> that have been marked as "in use".
>
> Signed-off-by: John Snow <js...@redhat.com>
> ---
> block/dirty-bitmap.c | 19 +++++++++++++++++++
> include/block/dirty-bitmap.h | 2 ++
> qapi/block-core.json | 9 +++++++--
> 3 files changed, 28 insertions(+), 2 deletions(-)
>
> diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
> index fc390cae94..b1879d7fbd 100644
> --- a/block/dirty-bitmap.c
> +++ b/block/dirty-bitmap.c
> @@ -47,6 +47,9 @@ struct BdrvDirtyBitmap {
> and this bitmap must remain unchanged
> while
> this flag is set. */
> bool persistent; /* bitmap must be saved to owner disk image
> */
> + bool inconsistent; /* bitmap is persistent, but not owned by
> QEMU.
> + * It cannot be used at all in any way,
> except
> + * a QMP user can remove or clear it. */
> bool migration; /* Bitmap is selected for migration, it
> should
> not be stored on the next inactivation
> (persistent flag doesn't matter until
> next
> @@ -461,6 +464,8 @@ BlockDirtyInfoList
> *bdrv_query_dirty_bitmaps(BlockDriverState *bs)
> info->recording = bdrv_dirty_bitmap_recording(bm);
> info->busy = bdrv_dirty_bitmap_busy(bm);
> info->persistent = bm->persistent;
> + info->has_inconsistent = bm->inconsistent;
> + info->inconsistent = bm->inconsistent;
> entry->value = info;
> *plist = entry;
> plist = &entry->next;
> @@ -708,6 +713,15 @@ void bdrv_dirty_bitmap_set_persistance(BdrvDirtyBitmap
> *bitmap, bool persistent)
> qemu_mutex_unlock(bitmap->mutex);
> }
>
> +/* Called with BQL taken. */
Do we need BQL if we use mutex explicitly?
> +void bdrv_dirty_bitmap_set_inconsistent(BdrvDirtyBitmap *bitmap, bool value)
> +{
> + qemu_mutex_lock(bitmap->mutex);
> + bitmap->inconsistent = value;
> + bitmap->disabled = value;
So, set inconsistent to false will enable the bitmap? Seems tricky.
> + qemu_mutex_unlock(bitmap->mutex);
> +}
> +
> /* Called with BQL taken. */
> void bdrv_dirty_bitmap_set_migration(BdrvDirtyBitmap *bitmap, bool
> migration)
> {
> @@ -721,6 +735,11 @@ bool bdrv_dirty_bitmap_get_persistance(BdrvDirtyBitmap
> *bitmap)
> return bitmap->persistent && !bitmap->migration;
> }
>
> +bool bdrv_dirty_bitmap_inconsistent(BdrvDirtyBitmap *bitmap)
> +{
> + return bitmap->inconsistent;
> +}
> +
> bool bdrv_has_changed_persistent_bitmaps(BlockDriverState *bs)
> {
> BdrvDirtyBitmap *bm;
> diff --git a/include/block/dirty-bitmap.h b/include/block/dirty-bitmap.h
> index ba8477b73f..c0d37702fd 100644
> --- a/include/block/dirty-bitmap.h
> +++ b/include/block/dirty-bitmap.h
> @@ -68,6 +68,7 @@ void bdrv_dirty_bitmap_deserialize_finish(BdrvDirtyBitmap
> *bitmap);
> void bdrv_dirty_bitmap_set_readonly(BdrvDirtyBitmap *bitmap, bool value);
> void bdrv_dirty_bitmap_set_persistance(BdrvDirtyBitmap *bitmap,
> bool persistent);
> +void bdrv_dirty_bitmap_set_inconsistent(BdrvDirtyBitmap *bitmap, bool value);
> void bdrv_dirty_bitmap_set_busy(BdrvDirtyBitmap *bitmap, bool busy);
> void bdrv_merge_dirty_bitmap(BdrvDirtyBitmap *dest, const BdrvDirtyBitmap
> *src,
> HBitmap **backup, Error **errp);
> @@ -91,6 +92,7 @@ bool bdrv_dirty_bitmap_readonly(const BdrvDirtyBitmap
> *bitmap);
> bool bdrv_has_readonly_bitmaps(BlockDriverState *bs);
> bool bdrv_dirty_bitmap_get_autoload(const BdrvDirtyBitmap *bitmap);
> bool bdrv_dirty_bitmap_get_persistance(BdrvDirtyBitmap *bitmap);
> +bool bdrv_dirty_bitmap_inconsistent(BdrvDirtyBitmap *bitmap);
> bool bdrv_dirty_bitmap_busy(BdrvDirtyBitmap *bitmap);
> bool bdrv_has_changed_persistent_bitmaps(BlockDriverState *bs);
> BdrvDirtyBitmap *bdrv_dirty_bitmap_next(BlockDriverState *bs,
> diff --git a/qapi/block-core.json b/qapi/block-core.json
> index 5d1d182447..f6b6dc2aff 100644
> --- a/qapi/block-core.json
> +++ b/qapi/block-core.json
> @@ -470,12 +470,17 @@
> # @persistent: true if the bitmap will eventually be flushed to persistent
> # storage (since 4.0)
> #
> +# @inconsistent: true if this is a persistent bitmap that QEMU does not own.
> +# Implies @recording to be false and @busy to be true. To
> +# reclaim ownership, see @block-dirty-bitmap-remove or
> +# @block-dirty-bitmap-clear (since 4.0)
> +#
> # Since: 1.3
> ##
> { 'struct': 'BlockDirtyInfo',
> 'data': {'*name': 'str', 'count': 'int', 'granularity': 'uint32',
> - 'recording': 'bool', 'busy': 'bool',
> - 'status': 'DirtyBitmapStatus', 'persistent': 'bool' } }
> + 'recording': 'bool', 'busy': 'bool', 'status':
> 'DirtyBitmapStatus',
> + 'persistent': 'bool', '*inconsistent': 'bool' } }
>
> ##
> # @Qcow2BitmapInfoFlags:
>
--
Best regards,
Vladimir
