Re: [Qemu-devel] [PATCH V17 02/12] quorum: Create BDRVQuorumState and BlkDriver and do init.

[Max Reitz <mreitz@redhat.com>]

On 12.02.2014 23:06, Benoît Canet wrote:
> From: Benoît Canet <benoit@irqsave.net>
>
> Create the structure holding the quorum settings and write the minimal block
> driver instanciation boilerplate.
>
> Signed-off-by: Benoit Canet <benoit@irqsave.net>
> Reviewed-by: Max Reitz <mreitz@redhat.com>
> ---
>   block/quorum.c | 31 +++++++++++++++++++++++++++++++
>   1 file changed, 31 insertions(+)
>
> diff --git a/block/quorum.c b/block/quorum.c
> index 950f5cc..36c5bb8 100644
> --- a/block/quorum.c
> +++ b/block/quorum.c
> @@ -15,6 +15,23 @@
>   
>   #include "block/block_int.h"
>   
> +/* the following structure holds the state of one quorum instance */
> +typedef struct BDRVQuorumState {
> +    BlockDriverState **bs; /* children BlockDriverStates */
> +    int num_children;      /* children count */
> +    int threshold;         /* if less than threshold children reads gave the
> +                            * same result a quorum error occurs.
> +                            */
> +    bool is_blkverify;     /* true if the driver is in blkverify mode
> +                            * Writes are mirrored on two children devices.
> +                            * On reads the two children devices contents are

Probably better with apostrophe: "children devices' contents".

> +                            * compared and when a difference is spotted its

Since we're not rooting for an error, I'd prefer an "if" instead of "when".

> +                            * location is printed and the code abort.

"aborts"

Reviewed-by: Max Reitz <mreitz@redhat.com>

> +                            * It is useful to debug other block drivers by
> +                            * comparing them with a reference one.
> +                            */
> +} BDRVQuorumState;
> +
>   typedef struct QuorumAIOCB QuorumAIOCB;
>   
>   /* Quorum will create one instance of the following structure per operation it
> @@ -51,3 +68,17 @@ struct QuorumAIOCB {
>       bool is_read;
>       int vote_ret;
>   };
> +
> +static BlockDriver bdrv_quorum = {
> +    .format_name        = "quorum",
> +    .protocol_name      = "quorum",
> +
> +    .instance_size      = sizeof(BDRVQuorumState),
> +};
> +
> +static void bdrv_quorum_init(void)
> +{
> +    bdrv_register(&bdrv_quorum);
> +}
> +
> +block_init(bdrv_quorum_init);