From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52734) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eFkJx-000172-Vf for qemu-devel@nongnu.org; Fri, 17 Nov 2017 12:20:55 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eFkJw-00045J-Ox for qemu-devel@nongnu.org; Fri, 17 Nov 2017 12:20:53 -0500 References: <20171030163309.75770-1-vsementsov@virtuozzo.com> <20171030163309.75770-5-vsementsov@virtuozzo.com> From: John Snow Message-ID: Date: Fri, 17 Nov 2017 12:20:31 -0500 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH v8 04/14] block/dirty-bitmap: add bdrv_dirty_bitmap_set_frozen List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Vladimir Sementsov-Ogievskiy , qemu-block@nongnu.org, qemu-devel@nongnu.org, famz@redhat.com Cc: kwolf@redhat.com, peter.maydell@linaro.org, lirans@il.ibm.com, quintela@redhat.com, armbru@redhat.com, mreitz@redhat.com, stefanha@redhat.com, den@openvz.org, amit.shah@redhat.com, pbonzini@redhat.com, dgilbert@redhat.com On 11/17/2017 09:46 AM, Vladimir Sementsov-Ogievskiy wrote: > 14.11.2017 02:32, John Snow wrote: >> >> On 10/30/2017 12:32 PM, Vladimir Sementsov-Ogievskiy wrote: >>> Make it possible to set bitmap 'frozen' without a successor. >>> This is needed to protect the bitmap during outgoing bitmap postcopy >>> migration. >>> >>> Signed-off-by: Vladimir Sementsov-Ogievskiy >>> --- >>> =C2=A0 include/block/dirty-bitmap.h |=C2=A0 1 + >>> =C2=A0 block/dirty-bitmap.c=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0 | 22 ++++++++++++++++++++-- >>> =C2=A0 2 files changed, 21 insertions(+), 2 deletions(-) >>> >>> diff --git a/include/block/dirty-bitmap.h b/include/block/dirty-bitma= p.h >>> index a9e2a92e4f..ae6d697850 100644 >>> --- a/include/block/dirty-bitmap.h >>> +++ b/include/block/dirty-bitmap.h >>> @@ -39,6 +39,7 @@ uint32_t >>> bdrv_get_default_bitmap_granularity(BlockDriverState *bs); >>> =C2=A0 uint32_t bdrv_dirty_bitmap_granularity(const BdrvDirtyBitmap *= bitmap); >>> =C2=A0 bool bdrv_dirty_bitmap_enabled(BdrvDirtyBitmap *bitmap); >>> =C2=A0 bool bdrv_dirty_bitmap_frozen(BdrvDirtyBitmap *bitmap); >>> +void bdrv_dirty_bitmap_set_frozen(BdrvDirtyBitmap *bitmap, bool >>> frozen); >>> =C2=A0 const char *bdrv_dirty_bitmap_name(const BdrvDirtyBitmap *bitm= ap); >>> =C2=A0 int64_t bdrv_dirty_bitmap_size(const BdrvDirtyBitmap *bitmap); >>> =C2=A0 DirtyBitmapStatus bdrv_dirty_bitmap_status(BdrvDirtyBitmap *bi= tmap); >>> diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c >>> index 7578863aa1..67fc6bd6e0 100644 >>> --- a/block/dirty-bitmap.c >>> +++ b/block/dirty-bitmap.c >>> @@ -40,6 +40,8 @@ struct BdrvDirtyBitmap { >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 QemuMutex *mutex; >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 HBitmap *bitmap;=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 /* Dirty bitmap implementation= */ >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 HBitmap *meta;=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 /* Meta dirty bitm= ap */ >>> +=C2=A0=C2=A0=C2=A0 bool frozen;=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2= =A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 /* Bitmap is frozen, = it can't be >>> modified >>> +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2= =A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 through QMP = */ >> I hesitate, because this now means that we have two independent bits o= f >> state we need to update and maintain consistency with. >=20 > it was your proposal))) >=20 > https://lists.gnu.org/archive/html/qemu-devel/2017-07/msg01172.html >=20 > " > Your new use case here sounds like Frozen to me, but it simply does not > have an anonymous successor to force it to be recognized as "frozen." W= e > can add a `bool protected` or `bool frozen` field to force recognition > of this status and adjust the json documentation accordingly. >=20 > I think then we'd have four recognized states: >=20 > FROZEN: Cannot be reset/deleted. Bitmap is in-use by a block job or > other internal process. Bitmap is otherwise ACTIVE. > DISABLED: Not recording any writes (by choice.) > READONLY: Not able to record any writes (by necessity.) > ACTIVE: Normal bitmap status. >=20 > Sound right? > " >=20 >=20 I was afraid you'd say that :( It's okay, anyway. I shouldn't let myself go so long between reviews like this, because you catch me changing my mind. Anyway, please go ahead with it. I don't want to delay you on something that works because I can't make up *my* mind.