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Re: [PATCH 3/4] block: add dbg_dump_block_layer()
From: |
Eric Blake |
Subject: |
Re: [PATCH 3/4] block: add dbg_dump_block_layer() |
Date: |
Thu, 19 Nov 2020 11:02:36 -0600 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.4.0 |
On 11/19/20 7:16 AM, Vladimir Sementsov-Ogievskiy wrote:
> Add function for debugging: we already have x-debug-query-block-graph
> qmp command and scripts/render_block_graph.py which can dump
> block-layer graph for running vm using qmp command. But when debug
> block layer code, its often needed to dump some intermediate state
> during some operation, so separate qmp command doesn't help.
>
> So, let's introduce a function which can dump needed information into
> json file.
>
> In next commit we'll update scripts/render_block_graph.py so that it
> will be able to parse json files.
>
> For new function to not crash if we have mirror_top filter node not yet
> bdrv_append()ed (to debug why it can't be appended), make
> bdrv_get_allocated_file_size() and bdrv_refresh_filename() not crash on
> filters without a child.
>
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
> ---
> +++ b/qapi/block-core.json
> @@ -1908,6 +1908,19 @@
> ##
> { 'command': 'x-debug-query-block-graph', 'returns': 'XDbgBlockGraph' }
>
> +##
> +# @XDbgBlockLayerDump:
> +#
> +# Unite query-named-block-nodes, query-block-jobs and
> +# x-debug-query-block-graph results into one structure for block_layer_dump()
> +# function.
> +#
> +# Since: 5.3
The next release will be numbered 6.0, not 5.3.
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3226
Virtualization: qemu.org | libvirt.org