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Re: [Qemu-devel] [PATCH v3 01/10] block/dirty-bitmap: add recording and
From: |
Vladimir Sementsov-Ogievskiy |
Subject: |
Re: [Qemu-devel] [PATCH v3 01/10] block/dirty-bitmap: add recording and busy properties |
Date: |
Mon, 25 Feb 2019 15:01:56 +0000 |
23.02.2019 3:06, John Snow wrote:
> The current API allows us to report a single status, which we've defined as:
>
> Frozen: has a successor, treated as qmp_locked, may or may not be enabled.
> Locked: no successor, qmp_locked. may or may not be enabled.
> Disabled: Not frozen or locked, disabled.
> Active: Not frozen, locked, or disabled.
>
> The problem is that both "Frozen" and "Locked" mean nearly the same thing,
> and that both of them do not intuit whether they are recording guest writes
> or not.
>
> This patch deprecates that status field and introduces two orthogonal
> properties instead to replace it.
>
> Signed-off-by: John Snow <address@hidden>
> ---
> block/dirty-bitmap.c | 9 +++++++++
> qapi/block-core.json | 10 +++++++++-
> qemu-deprecated.texi | 6 ++++++
> tests/qemu-iotests/236.out | 28 ++++++++++++++++++++++++++++
> 4 files changed, 52 insertions(+), 1 deletion(-)
>
> diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
> index c6d4acebfa..101383b3af 100644
> --- a/block/dirty-bitmap.c
> +++ b/block/dirty-bitmap.c
> @@ -226,6 +226,13 @@ DirtyBitmapStatus
> bdrv_dirty_bitmap_status(BdrvDirtyBitmap *bitmap)
> }
> }
>
> +/* Called with BQL taken. */
> +static bool bdrv_dirty_bitmap_recording(BdrvDirtyBitmap *bitmap)
> +{
> + return !bitmap->disabled || (bitmap->successor &&
> + !bitmap->successor->disabled);
> +}
> +
> /**
> * Create a successor bitmap destined to replace this bitmap after an
> operation.
> * Requires that the bitmap is not frozen and has no successor.
> @@ -448,6 +455,8 @@ BlockDirtyInfoList
> *bdrv_query_dirty_bitmaps(BlockDriverState *bs)
> info->has_name = !!bm->name;
> info->name = g_strdup(bm->name);
> info->status = bdrv_dirty_bitmap_status(bm);
> + info->recording = bdrv_dirty_bitmap_recording(bm);
> + info->busy = bdrv_dirty_bitmap_user_locked(bm);
> info->persistent = bm->persistent;
> entry->value = info;
> *plist = entry;
> diff --git a/qapi/block-core.json b/qapi/block-core.json
> index 2b8afbb924..6e543594b3 100644
> --- a/qapi/block-core.json
> +++ b/qapi/block-core.json
> @@ -458,7 +458,14 @@
> #
> # @granularity: granularity of the dirty bitmap in bytes (since 1.4)
> #
> -# @status: current status of the dirty bitmap (since 2.4)
> +# @status: Deprecated in favor of @recording and @locked. (since 2.4)
> +#
> +# @recording: true if the bitmap is recording new writes from the guest.
> +# Replaces `active` and `disabled` statuses. (since 4.0)
> +#
> +# @busy: true if the bitmap is in-use by some operation (NBD or jobs)
> +# and cannot be modified via QMP or used by another operation.
> +# Replaces `locked` and `frozen` statuses. (since 4.0)
Don't we want instead an array of flags? Which will include also persistent and
inconsistent?
> #
> # @persistent: true if the bitmap will eventually be flushed to persistent
> # storage (since 4.0)
> @@ -467,6 +474,7 @@
> ##
> { 'struct': 'BlockDirtyInfo',
> 'data': {'*name': 'str', 'count': 'int', 'granularity': 'uint32',
> + 'recording': 'bool', 'busy': 'bool',
> 'status': 'DirtyBitmapStatus', 'persistent': 'bool' } }
>
> ##
> diff --git a/qemu-deprecated.texi b/qemu-deprecated.texi
> index 45c57952da..4c7ae8180f 100644
> --- a/qemu-deprecated.texi
> +++ b/qemu-deprecated.texi
> @@ -67,6 +67,12 @@ topologies described with -smp include all possible cpus,
> i.e.
> "autoload" parameter is now ignored. All bitmaps are automatically loaded
> from qcow2 images.
>
> address@hidden query-block result field(s) dirty-bitmaps[i].status (since 4.0)
> +
> +The ``status'' field of the ``BlockDirtyInfo'' structure, returned by
> +the query-block command is deprecated. Two new boolean fields,
> +``recording'' and ``busy'' effectively replace it.
> +
> @subsection query-cpus (since 2.12.0)
>
> The ``query-cpus'' command is replaced by the ``query-cpus-fast'' command.
> diff --git a/tests/qemu-iotests/236.out b/tests/qemu-iotests/236.out
> index 5006f7bca1..815cd053f0 100644
> --- a/tests/qemu-iotests/236.out
> +++ b/tests/qemu-iotests/236.out
> @@ -22,17 +22,21 @@ write -P0xcd 0x3ff0000 64k
> "bitmaps": {
> "drive0": [
> {
> + "busy": false,
> "count": 262144,
> "granularity": 65536,
> "name": "bitmapB",
> "persistent": false,
> + "recording": true,
> "status": "active"
> },
> {
> + "busy": false,
> "count": 262144,
> "granularity": 65536,
> "name": "bitmapA",
> "persistent": false,
> + "recording": true,
> "status": "active"
> }
> ]
> @@ -84,17 +88,21 @@ write -P0xcd 0x3ff0000 64k
> "bitmaps": {
> "drive0": [
> {
> + "busy": false,
> "count": 262144,
> "granularity": 65536,
> "name": "bitmapB",
> "persistent": false,
> + "recording": true,
> "status": "active"
> },
> {
> + "busy": false,
> "count": 262144,
> "granularity": 65536,
> "name": "bitmapA",
> "persistent": false,
> + "recording": true,
> "status": "active"
> }
> ]
> @@ -184,24 +192,30 @@ write -P0xea 0x3fe0000 64k
> "bitmaps": {
> "drive0": [
> {
> + "busy": false,
> "count": 393216,
> "granularity": 65536,
> "name": "bitmapC",
> "persistent": false,
> + "recording": false,
> "status": "disabled"
> },
> {
> + "busy": false,
> "count": 262144,
> "granularity": 65536,
> "name": "bitmapB",
> "persistent": false,
> + "recording": false,
> "status": "disabled"
> },
> {
> + "busy": false,
> "count": 458752,
> "granularity": 65536,
> "name": "bitmapA",
> "persistent": false,
> + "recording": false,
> "status": "disabled"
> }
> ]
> @@ -251,24 +265,30 @@ write -P0xea 0x3fe0000 64k
> "bitmaps": {
> "drive0": [
> {
> + "busy": false,
> "count": 393216,
> "granularity": 65536,
> "name": "bitmapC",
> "persistent": false,
> + "recording": false,
> "status": "disabled"
> },
> {
> + "busy": false,
> "count": 262144,
> "granularity": 65536,
> "name": "bitmapB",
> "persistent": false,
> + "recording": false,
> "status": "disabled"
> },
> {
> + "busy": false,
> "count": 458752,
> "granularity": 65536,
> "name": "bitmapA",
> "persistent": false,
> + "recording": false,
> "status": "disabled"
> }
> ]
> @@ -311,31 +331,39 @@ write -P0xea 0x3fe0000 64k
> "bitmaps": {
> "drive0": [
> {
> + "busy": false,
> "count": 458752,
> "granularity": 65536,
> "name": "bitmapD",
> "persistent": false,
> + "recording": false,
> "status": "disabled"
> },
> {
> + "busy": false,
> "count": 393216,
> "granularity": 65536,
> "name": "bitmapC",
> "persistent": false,
> + "recording": false,
> "status": "disabled"
> },
> {
> + "busy": false,
> "count": 262144,
> "granularity": 65536,
> "name": "bitmapB",
> "persistent": false,
> + "recording": false,
> "status": "disabled"
> },
> {
> + "busy": false,
> "count": 458752,
> "granularity": 65536,
> "name": "bitmapA",
> "persistent": false,
> + "recording": false,
> "status": "disabled"
> }
> ]
>
--
Best regards,
Vladimir
- [Qemu-devel] [PATCH v3 00/10] dirty-bitmaps: deprecate @status field, John Snow, 2019/02/22
- [Qemu-devel] [PATCH v3 02/10] block/dirty-bitmaps: rename frozen predicate helper, John Snow, 2019/02/22
- [Qemu-devel] [PATCH v3 01/10] block/dirty-bitmap: add recording and busy properties, John Snow, 2019/02/22
- [Qemu-devel] [PATCH v3 04/10] block/dirty-bitmap: change semantics of enabled predicate, John Snow, 2019/02/22
- [Qemu-devel] [PATCH v3 09/10] blockdev: remove unused paio parameter documentation, John Snow, 2019/02/22
- [Qemu-devel] [PATCH v3 06/10] block/dirty-bitmap: explicitly lock bitmaps with successors, John Snow, 2019/02/22
- [Qemu-devel] [PATCH v3 05/10] nbd: change error checking order for bitmaps, John Snow, 2019/02/22