Re: [Qemu-devel] [PATCH v5 9/9] qapi: query-blockstat: add driver specific file-posix stats

[Vladimir Sementsov-Ogievskiy]

31.10.2018 14:35, Anton Nefedov wrote:
> A block driver can provide a callback to report driver-specific
> statistics.
> 
> file-posix driver now reports discard statistics
> 
> Signed-off-by: Anton Nefedov <address@hidden>
> ---
>   qapi/block-core.json      | 39 +++++++++++++++++++++++++++++++++++++++
>   include/block/block.h     |  1 +
>   include/block/block_int.h |  1 +
>   block.c                   |  9 +++++++++
>   block/file-posix.c        | 17 +++++++++++++++++
>   block/qapi.c              |  5 +++++
>   6 files changed, 72 insertions(+)
> 
> diff --git a/qapi/block-core.json b/qapi/block-core.json
> index 01da84cb61..cd0344435e 100644
> --- a/qapi/block-core.json
> +++ b/qapi/block-core.json
> @@ -877,6 +877,42 @@
>              '*x_wr_latency_histogram': 'BlockLatencyHistogramInfo',
>              '*x_flush_latency_histogram': 'BlockLatencyHistogramInfo' } }
>   
> +##
> +# @BlockStatsSpecificFile:
> +#
> +# File driver statistics
> +#
> +# @discard-nb-ok: The number of succeeded discard operations performed by
> +#                 the driver.
> +#
> +# @discard-nb-failed: The number of failed discard operations performed by
> +#                     the driver.
> +#
> +# @discard-bytes-ok: The number of bytes discarded by the driver.
> +#
> +# Since 3.1

colon after Since:
Since: 3.1

> +##
> +{ 'struct': 'BlockStatsSpecificFile',
> +  'data': {
> +      'discard-nb-ok': 'int',
> +      'discard-nb-failed': 'int',
> +      'discard-bytes-ok': 'int'
> +  } }

the common stile here is no extra \n around braces, like:

{ 'struct': 'BlockStatsSpecificFile',
   'data': { 'discard-nb-ok': 'int',
             'discard-nb-failed': 'int',
             'discard-bytes-ok': 'int' } }


> +
> +##
> +# @BlockStatsSpecific:
> +#
> +# Block driver specific statistics
> +#
> +# Since: 3.1
> +##
> +{ 'union': 'BlockStatsSpecific',
> +  'base': { 'driver': 'BlockdevDriver' },
> +  'discriminator': 'driver',
> +  'data': {
> +      'file': 'BlockStatsSpecificFile'
> +  } }

and here.

> +
>   ##
>   # @BlockStats:
>   #
> @@ -892,6 +928,8 @@
>   #
>   # @stats:  A @BlockDeviceStats for the device.
>   #
> +# @driver-specific: Optional driver-specific stats. (Since 3.1)
> +#
>   # @parent: This describes the file block device if it has one.
>   #          Contains recursively the statistics of the underlying
>   #          protocol (e.g. the host file for a qcow2 image). If there is
> @@ -905,6 +943,7 @@
>   { 'struct': 'BlockStats',
>     'data': {'*device': 'str', '*qdev': 'str', '*node-name': 'str',
>              'stats': 'BlockDeviceStats',
> +           '*driver-specific': 'BlockStatsSpecific',

[offtopic]
hmm, do anyone know, why thunderbird when quoting patches adds "> " between all 
lines except ones starting with a space, and for lines, starting with space, it 
adds ">  " (two extra spaces, not one), which leads to wrong indenting in 
quotes? And how to fix that?
[/offtopic]

>              '*parent': 'BlockStats',
>              '*backing': 'BlockStats'} }
>   
> diff --git a/include/block/block.h b/include/block/block.h
> index b189cf422e..07a3b31386 100644
> --- a/include/block/block.h
> +++ b/include/block/block.h
> @@ -475,6 +475,7 @@ const char *bdrv_get_device_or_node_name(const 
> BlockDriverState *bs);
>   int bdrv_get_flags(BlockDriverState *bs);
>   int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi);
>   ImageInfoSpecific *bdrv_get_specific_info(BlockDriverState *bs);
> +BlockStatsSpecific *bdrv_get_specific_stats(BlockDriverState *bs);
>   void bdrv_round_to_clusters(BlockDriverState *bs,
>                               int64_t offset, int64_t bytes,
>                               int64_t *cluster_offset,
> diff --git a/include/block/block_int.h b/include/block/block_int.h
> index f605622216..236d4aceef 100644
> --- a/include/block/block_int.h
> +++ b/include/block/block_int.h
> @@ -320,6 +320,7 @@ struct BlockDriver {
>                                     Error **errp);
>       int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi);
>       ImageInfoSpecific *(*bdrv_get_specific_info)(BlockDriverState *bs);
> +    BlockStatsSpecific *(*bdrv_get_specific_stats)(BlockDriverState *bs);
>   
>       int coroutine_fn (*bdrv_save_vmstate)(BlockDriverState *bs,
>                                             QEMUIOVector *qiov,
> diff --git a/block.c b/block.c
> index 95d8635aa1..1e5bba4ac6 100644
> --- a/block.c
> +++ b/block.c
> @@ -4244,6 +4244,15 @@ ImageInfoSpecific 
> *bdrv_get_specific_info(BlockDriverState *bs)
>       return NULL;
>   }
>   
> +BlockStatsSpecific *bdrv_get_specific_stats(BlockDriverState *bs)
> +{
> +    BlockDriver *drv = bs->drv;
> +    if (!drv || !drv->bdrv_get_specific_stats) {
> +        return NULL;
> +    }
> +    return drv->bdrv_get_specific_stats(bs);
> +}
> +
>   void bdrv_debug_event(BlockDriverState *bs, BlkdebugEvent event)
>   {
>       if (!bs || !bs->drv || !bs->drv->bdrv_debug_event) {
> diff --git a/block/file-posix.c b/block/file-posix.c
> index 1a7126046c..a0a06585ab 100644
> --- a/block/file-posix.c
> +++ b/block/file-posix.c
> @@ -2630,6 +2630,21 @@ static int raw_get_info(BlockDriverState *bs, 
> BlockDriverInfo *bdi)
>       return 0;
>   }
>   
> +static BlockStatsSpecific *raw_get_specific_stats(BlockDriverState *bs)
> +{
> +    BDRVRawState *s = bs->opaque;
> +    BlockStatsSpecific *stats = g_new(BlockStatsSpecific, 1);
> +
> +    stats->driver = BLOCKDEV_DRIVER_FILE;

it should be BLOCKDEV_DRIVER_HOST_DEVICE for bdrv_host_device driver I think.

> +    stats->u.file = (BlockStatsSpecificFile){

and than, here we'll have "different" union field - host_device. (and for 
code-style, whitespace before brace)

> +        .discard_nb_ok = s->stats.discard_nb_ok,
> +        .discard_nb_failed = s->stats.discard_nb_failed,
> +        .discard_bytes_ok = s->stats.discard_bytes_ok,
> +    };
> +
> +    return stats;
> +}
> +
>   static QemuOptsList raw_create_opts = {
>       .name = "raw-create-opts",
>       .head = QTAILQ_HEAD_INITIALIZER(raw_create_opts.head),
> @@ -2741,6 +2756,7 @@ BlockDriver bdrv_file = {
>       .bdrv_get_info = raw_get_info,
>       .bdrv_get_allocated_file_size
>                           = raw_get_allocated_file_size,
> +    .bdrv_get_specific_stats = raw_get_specific_stats,
>       .bdrv_check_perm = raw_check_perm,
>       .bdrv_set_perm   = raw_set_perm,
>       .bdrv_abort_perm_update = raw_abort_perm_update,
> @@ -3226,6 +3242,7 @@ static BlockDriver bdrv_host_device = {
>       .bdrv_get_info = raw_get_info,
>       .bdrv_get_allocated_file_size
>                           = raw_get_allocated_file_size,
> +    .bdrv_get_specific_stats = raw_get_specific_stats,
>       .bdrv_check_perm = raw_check_perm,
>       .bdrv_set_perm   = raw_set_perm,
>       .bdrv_abort_perm_update = raw_abort_perm_update,
> diff --git a/block/qapi.c b/block/qapi.c
> index df31f351d2..74f762ea6c 100644
> --- a/block/qapi.c
> +++ b/block/qapi.c
> @@ -535,6 +535,11 @@ static BlockStats *bdrv_query_bds_stats(BlockDriverState 
> *bs,
>   
>       s->stats->wr_highest_offset = stat64_get(&bs->wr_highest_offset);
>   
> +    s->driver_specific = bdrv_get_specific_stats(bs);
> +    if (s->driver_specific) {
> +        s->has_driver_specific = true;
> +    }
> +
>       if (bs->file) {
>           s->has_parent = true;
>           s->parent = bdrv_query_bds_stats(bs->file->bs, blk_level);
> 


-- 
Best regards,
Vladimir