Re: [Qemu-devel] [PATCH RFC 3/7] replication: add shared-disk and shared-disk-id options

[Changlong Xie <xiecl.fnst@cn.fujitsu.com>]

On 10/20/2016 09:57 PM, zhanghailiang wrote:
> We use these two options to identify which disk is
> shared
>
> Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
> Signed-off-by: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
> ---
>   block/replication.c | 33 +++++++++++++++++++++++++++++++++
>   1 file changed, 33 insertions(+)
>
> diff --git a/block/replication.c b/block/replication.c
> index 3bd1cf1..2a2fdb2 100644
> --- a/block/replication.c
> +++ b/block/replication.c
> @@ -25,9 +25,12 @@
>   typedef struct BDRVReplicationState {
>       ReplicationMode mode;
>       int replication_state;
> +    bool is_shared_disk;
> +    char *shared_disk_id;
>       BdrvChild *active_disk;
>       BdrvChild *hidden_disk;
>       BdrvChild *secondary_disk;
> +    BdrvChild *primary_disk;
>       char *top_id;
>       ReplicationState *rs;
>       Error *blocker;
> @@ -53,6 +56,9 @@ static void replication_stop(ReplicationState *rs, bool failover,
>
>   #define REPLICATION_MODE        "mode"
>   #define REPLICATION_TOP_ID      "top-id"
> +#define REPLICATION_SHARED_DISK "shared-disk"
> +#define REPLICATION_SHARED_DISK_ID "shared-disk-id"
> +
>   static QemuOptsList replication_runtime_opts = {
>       .name = "replication",
>       .head = QTAILQ_HEAD_INITIALIZER(replication_runtime_opts.head),
> @@ -65,6 +71,14 @@ static QemuOptsList replication_runtime_opts = {
>               .name = REPLICATION_TOP_ID,
>               .type = QEMU_OPT_STRING,
>           },
> +        {
> +            .name = REPLICATION_SHARED_DISK_ID,
> +            .type = QEMU_OPT_STRING,
> +        },
> +        {
> +            .name = REPLICATION_SHARED_DISK,
> +            .type = QEMU_OPT_BOOL,
> +        },
>           { /* end of list */ }
>       },
>   };
> @@ -85,6 +99,8 @@ static int replication_open(BlockDriverState *bs, QDict *options,
>       QemuOpts *opts = NULL;
>       const char *mode;
>       const char *top_id;
> +    const char *shared_disk_id;
> +    BlockBackend *blk;
>
>       ret = -EINVAL;
>       opts = qemu_opts_create(&replication_runtime_opts, NULL, 0, &error_abort);
> @@ -114,6 +130,22 @@ static int replication_open(BlockDriverState *bs, QDict *options,
>                      "The option mode's value should be primary or secondary");
>           goto fail;
>       }

Now we have four runtime options 
"mode"/"top-id"/"shared-disk"/"shared-disk-id". But the current checking 
logic is too weak, i think you need enhance it to avoid opts misusage.

> +    s->is_shared_disk = qemu_opt_get_bool(opts, REPLICATION_SHARED_DISK,
> +                                        false);

Missing one space.

> +    if (s->is_shared_disk && (s->mode == REPLICATION_MODE_PRIMARY)) {
> +        shared_disk_id = qemu_opt_get(opts, REPLICATION_SHARED_DISK_ID);
> +        if (!shared_disk_id) {
> +            error_setg(&local_err, "Missing shared disk blk");
> +            goto fail;
> +        }
> +        s->shared_disk_id = g_strdup(shared_disk_id);
> +        blk = blk_by_name(s->shared_disk_id);
> +        if (!blk) {
> +            error_setg(&local_err, "There is no %s block", s->shared_disk_id);
> +            goto fail;
> +        }
> +        s->primary_disk = blk_root(blk);
> +    }
>
>       s->rs = replication_new(bs, &replication_ops);
>
> @@ -130,6 +162,7 @@ static void replication_close(BlockDriverState *bs)
>   {
>       BDRVReplicationState *s = bs->opaque;
>
> +    g_free(s->shared_disk_id);
>       if (s->replication_state == BLOCK_REPLICATION_RUNNING) {
>           replication_stop(s->rs, false, NULL);
>       }
>