Re: [Qemu-devel] [PATCH V9 01/11] quorum: Create quorum.c, add QuorumSingleAIOCB and QuorumAIOCB.

[Max Reitz <mreitz@redhat.com>]

On 2013-10-02 14:39, Benoît Canet wrote:
> Signed-off-by: Benoit Canet <benoit@irqsave.net>
> ---
>   block/Makefile.objs |  1 +
>   block/quorum.c      | 54 +++++++++++++++++++++++++++++++++++++++++++++++++++++
>   2 files changed, 55 insertions(+)
>   create mode 100644 block/quorum.c
>
> diff --git a/block/Makefile.objs b/block/Makefile.objs
> index 3bb85b5..05a65c2 100644
> --- a/block/Makefile.objs
> +++ b/block/Makefile.objs
> @@ -3,6 +3,7 @@ block-obj-y += qcow2.o qcow2-refcount.o qcow2-cluster.o qcow2-snapshot.o qcow2-c
>   block-obj-y += qed.o qed-gencb.o qed-l2-cache.o qed-table.o qed-cluster.o
>   block-obj-y += qed-check.o
>   block-obj-y += vhdx.o
> +block-obj-y += quorum.o
>   block-obj-y += parallels.o blkdebug.o blkverify.o
>   block-obj-y += snapshot.o qapi.o
>   block-obj-$(CONFIG_WIN32) += raw-win32.o win32-aio.o
> diff --git a/block/quorum.c b/block/quorum.c
> new file mode 100644
> index 0000000..76a1fbb
> --- /dev/null
> +++ b/block/quorum.c
> @@ -0,0 +1,54 @@
> +/*
> + * Quorum Block filter
> + *
> + * Copyright (C) 2012-2013 Nodalink, SARL.
> + *
> + * Author:
> + *   Benoît Canet <benoit.canet@irqsave.net>
> + *
> + * Based on the design and code of blkverify.c (Copyright (C) 2010 IBM, Corp)
> + * and blkmirror.c (Copyright (C) 2011 Red Hat, Inc).
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2 or later.
> + * See the COPYING file in the top-level directory.
> + */
> +
> +#include "block/block_int.h"
> +
> +typedef struct QuorumAIOCB QuorumAIOCB;
> +
> +/* Quorum will create one instance of the following structure per read/write
> + * operation it do on it's children.
I'd vote for "operation it performs on its children" or something like that.

Max

> + * So for each read/write operation coming from the upper layer there will be
> + * $children_count QuorumSingleAIOCB.
> + */
> +typedef struct QuorumSingleAIOCB {
> +    BlockDriverAIOCB *aiocb;
> +    QEMUIOVector qiov;
> +    uint8_t *buf;
> +    int ret;
> +    QuorumAIOCB *parent;
> +} QuorumSingleAIOCB;
> +
> +/* Quorum will use the following structure to track progress of each read/write
> + * operation received by the upper layer.
> + * This structure hold pointers to the QuorumSingleAIOCB structures instances
> + * used to do operations on each children and track overall progress.
> + */
> +struct QuorumAIOCB {
> +    BlockDriverAIOCB common;
> +
> +    /* Request metadata */
> +    uint64_t sector_num;
> +    int nb_sectors;
> +
> +    QEMUIOVector *qiov;         /* calling IOV */
> +
> +    QuorumSingleAIOCB *aios;    /* individual AIOs */
> +    int count;                  /* number of completed AIOCB */
> +    int success_count;          /* number of successfully completed AIOCB */
> +    bool *finished;             /* completion signal for cancel */
> +
> +    bool is_read;
> +    int vote_ret;
> +};