Re: [Qemu-devel] [PATCH 1/3] block: add bdrv_get_device_or_node_name()

[Markus Armbruster <armbru@redhat.com>]

Alberto Garcia <berto@igalia.com> writes:

> This function gets the device name associated with a BlockDriverState,
> or its node name if the device name is empty.
>
> Signed-off-by: Alberto Garcia <berto@igalia.com>
> ---
>  block.c               | 5 +++++
>  block/quorum.c        | 5 +----
>  include/block/block.h | 1 +
>  3 files changed, 7 insertions(+), 4 deletions(-)
>
> diff --git a/block.c b/block.c
> index 0fe97de..af284e3 100644
> --- a/block.c
> +++ b/block.c
> @@ -3920,6 +3920,11 @@ const char *bdrv_get_device_name(const BlockDriverState *bs)
>      return bs->blk ? blk_name(bs->blk) : "";
>  }
>  
> +const char *bdrv_get_device_or_node_name(const BlockDriverState *bs)
> +{
> +    return bs->blk ? blk_name(bs->blk) : bs->node_name;
> +}
> +

Does this have uses beyond identifying @bs to the user?

>  int bdrv_get_flags(BlockDriverState *bs)
>  {
>      return bs->open_flags;
> diff --git a/block/quorum.c b/block/quorum.c
> index 437b122..f91ef75 100644
> --- a/block/quorum.c
> +++ b/block/quorum.c
> @@ -226,10 +226,7 @@ static void quorum_report_bad(QuorumAIOCB *acb, char *node_name, int ret)
>  
>  static void quorum_report_failure(QuorumAIOCB *acb)
>  {
> -    const char *reference = bdrv_get_device_name(acb->common.bs)[0] ?
> -                            bdrv_get_device_name(acb->common.bs) :
> -                            acb->common.bs->node_name;
> -
> +    const char *reference = bdrv_get_device_or_node_name(acb->common.bs);
>      qapi_event_send_quorum_failure(reference, acb->sector_num,
>                                     acb->nb_sectors, &error_abort);
>  }

Preexisting: what if reference is null?

event.json suggests it can't be null:

    ##
    # @QUORUM_FAILURE
    #
    # Emitted by the Quorum block driver if it fails to establish a quorum
    #
    # @reference: device name if defined else node name
    #
    # @sector-num: number of the first sector of the failed read operation
    #
    # @sectors-count: failed read operation sector count
    #
    # Since: 2.0
    ##
    { 'event': 'QUORUM_FAILURE',
      'data': { 'reference': 'str', 'sector-num': 'int', 'sectors-count': 'int' } }

> diff --git a/include/block/block.h b/include/block/block.h
> index 4c57d63..b285e0d 100644
> --- a/include/block/block.h
> +++ b/include/block/block.h
> @@ -398,6 +398,7 @@ void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
>                           void *opaque);
>  const char *bdrv_get_node_name(const BlockDriverState *bs);
>  const char *bdrv_get_device_name(const BlockDriverState *bs);
> +const char *bdrv_get_device_or_node_name(const BlockDriverState *bs);
>  int bdrv_get_flags(BlockDriverState *bs);
>  int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num,
>                            const uint8_t *buf, int nb_sectors);