Re: [Qemu-devel] [PATCH] qemu-img info lists bitmap directory entries

[Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>]

27.11.2018 15:41, Andrey Shinkevich wrote:
> The 'Format specific information' of qemu-img info command will show
> the name, flags and granularity for every QCOW2 bitmap.
> 
> Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
> ---
> Dear colleagues,
> 
> With this patch, qemu-img info will display a name, flags and granularity
> information for every bitmap in the directory section of a QCOW2 image.
> That information appears in the 'Format specific information' section as
> it's shown in the following example:
> 

[...]

> --- a/block/qcow2.c
> +++ b/block/qcow2.c
> @@ -4254,6 +4254,13 @@ static ImageInfoSpecific *qcow2_get_specific_info(BlockDriverState *bs)
>       BDRVQcow2State *s = bs->opaque;
>       ImageInfoSpecific *spec_info;
>       QCryptoBlockInfo *encrypt_info = NULL;
> +    Error *local_err = NULL;
> +    Qcow2BitmapInfoList *bitmaps;
> +
> +    bitmaps = qcow2_get_bitmap_info_list(bs, &local_err);
> +    if (local_err != NULL) {
> +        error_report_err(local_err);
> +    }
>   
>       if (s->crypto != NULL) {
>           encrypt_info = qcrypto_block_get_info(s->crypto, &error_abort);
> @@ -4268,6 +4275,7 @@ static ImageInfoSpecific *qcow2_get_specific_info(BlockDriverState *bs)
>           *spec_info->u.qcow2.data = (ImageInfoSpecificQCow2){
>               .compat             = g_strdup("0.10"),
>               .refcount_bits      = s->refcount_bits,
> +            .bitmaps            = bitmaps,

Bitmaps are possible only in version >=3, so this line should be dropped



>           };
>       } else if (s->qcow_version == 3) {
>           *spec_info->u.qcow2.data = (ImageInfoSpecificQCow2){
> @@ -4279,6 +4287,8 @@ static ImageInfoSpecific *qcow2_get_specific_info(BlockDriverState *bs)
>                                     QCOW2_INCOMPAT_CORRUPT,
>               .has_corrupt        = true,
>               .refcount_bits      = s->refcount_bits,
> +            .has_bitmaps        = bitmaps ? true : false,
> +            .bitmaps            = bitmaps,
>           };
>       } else {
>           /* if this assertion fails, this probably means a new version was
> diff --git a/block/qcow2.h b/block/qcow2.h
> index 8662b68..0ec2b3d 100644
> --- a/block/qcow2.h
> +++ b/block/qcow2.h
> @@ -685,6 +685,8 @@ int qcow2_check_bitmaps_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
>                                     void **refcount_table,
>                                     int64_t *refcount_table_size);
>   bool qcow2_load_dirty_bitmaps(BlockDriverState *bs, Error **errp);
> +Qcow2BitmapInfoList *qcow2_get_bitmap_info_list(BlockDriverState *bs,
> +                                                Error **errp);
>   int qcow2_reopen_bitmaps_rw_hint(BlockDriverState *bs, bool *header_updated,
>                                    Error **errp);
>   int qcow2_reopen_bitmaps_rw(BlockDriverState *bs, Error **errp);
> diff --git a/qapi/block-core.json b/qapi/block-core.json
> index f4538fa..e021ead 100644
> --- a/qapi/block-core.json
> +++ b/qapi/block-core.json
> @@ -77,7 +77,8 @@
>         '*lazy-refcounts': 'bool',
>         '*corrupt': 'bool',
>         'refcount-bits': 'int',
> -      '*encrypt': 'ImageInfoSpecificQCow2Encryption'
> +      '*encrypt': 'ImageInfoSpecificQCow2Encryption',
> +      '*bitmaps': ['Qcow2BitmapInfo']
>     } }
>   
>   ##
> @@ -454,6 +455,38 @@
>              'status': 'DirtyBitmapStatus'} }
>   
>   ##
> +# @Qcow2BitmapInfoFlags:
> +#
> +# An enumeration of states that a bitmap can report to the user.
> +#
> +# @in-use: The bitmap was not saved correctly and may be inconsistent.
> +#
> +# @auto: The bitmap must reflect all changes of the virtual disk by any
> +#        application that would write to this qcow2 file.
> +#
> +# Since: 3.2

Hm, I heard, the next is 4.0?

> +##
> +{ 'enum': 'Qcow2BitmapInfoFlags',
> +  'data': ['in-use', 'auto'] }
> +
> +##
> +# @Qcow2BitmapInfo:
> +#
> +# Image bitmap information.
> +#
> +# @name: the name of the dirty bitmap
> +#
> +# @granularity: granularity of the dirty bitmap in bytes
> +#
> +# @flags: flags of the dirty bitmap

drop "dirty" word, they are just bitmaps by spec.

> +#
> +# Since: 3.2

and here, 4.0?

> +##
> +{ 'struct': 'Qcow2BitmapInfo',
> +  'data': {'name': 'str', 'granularity': 'uint32',
> +           'flags': ['Qcow2BitmapInfoFlags']} }
> +
> +##
>   # @BlockLatencyHistogramInfo:
>   #
>   # Block latency histogram.
> 


with these small fixes:

Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>


-- 
Best regards,
Vladimir