25.02.2019 17:18, Vladimir Sementsov-Ogievskiy wrote:
> 23.02.2019 3:22, 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 | 8 ++++++--
>> 3 files changed, 27 insertions(+), 2 deletions(-)
>>
>> diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
>> index 86c3b87ab9..9042c04788 100644
>> --- a/block/dirty-bitmap.c
>> +++ b/block/dirty-bitmap.c
>> @@ -46,6 +46,9 @@ 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 it. */
>> bool migration; /* Bitmap is selected for migration, it
>> should
>> not be stored on the next inactivation
>> (persistent flag doesn't matter until
>> next
>> @@ -462,6 +465,8 @@ 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;
>> @@ -709,6 +714,15 @@ void bdrv_dirty_bitmap_set_persistance(BdrvDirtyBitmap
>> *bitmap, bool persistent)
>> qemu_mutex_unlock(bitmap->mutex);
>> }
>> +/* Called with BQL taken. */
>> +void bdrv_dirty_bitmap_set_inconsistent(BdrvDirtyBitmap *bitmap)
>> +{
>> + qemu_mutex_lock(bitmap->mutex);
>> + bitmap->inconsistent = true;
>> + bitmap->disabled = true;
>> + qemu_mutex_unlock(bitmap->mutex);
>> +}
>
> Didn't you consider separate bdrv_create_inconsistent_bitmap, which will not
> allocate HBitmap?
>
> It may be done separately ofcourse..
>
>> +
>> /* Called with BQL taken. */
>> void bdrv_dirty_bitmap_set_migration(BdrvDirtyBitmap *bitmap, bool
>> migration)
>> {
>> @@ -722,6 +736,11 @@ 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..b270773f7e 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);
>> 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 6e543594b3..a7209fce22 100644
>> --- a/qapi/block-core.json
>> +++ b/qapi/block-core.json
>> @@ -470,12 +470,16 @@
>> # @persistent: true if the bitmap will eventually be flushed to persistent
>> # storage (since 4.0)
so, bitmap can't be inconsistent and persistent, as we don't want to flush
inconsistent bitmaps...
>> #
>> +# @inconsistent: true if this is a persistent bitmap that QEMU does not own.
>> +# Implies @recording and @busy to be false. To reclaim
>> +# ownership, use @block-dirty-bitmap-remove. (since 4.0)
>
> If we opened an image for rw with in-use bitmaps, the main thing about them
> not
> that QEMU doesn't own them, but that they are truly inconsistent. Nobody owns
> them.
>
> Also, "QEMU does not own" sound like somebody other may own. Then removing it
> don't
> seem a correct thing to do.
>
> And removing don't reclaim ownership, but just remove (looks like it was more
> about
> previous version with -clear).
>
> So for me something like: "Bitmap was not correctly saved after last usage,
> so it
> may be inconsistent. It's useless and only take place in a list. The only
> possible
> operation on it is remove." seems better.
>
>> +#
>> # 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
