Re: [Qemu-devel] [PATCH 08/11] qmp: add interface blockdev-snapshot-internal-sync

[Fam Zheng <famz@redhat.com>]

On Sat, 06/08 14:58, Wenchao Xia wrote:
> This interface can generate snapshot name automatically if it is not
> specified, since it is a single opertion.
> 
> Snapshot ID can't be specified in this interface.
> 
> Signed-off-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com>
> ---
>  blockdev.c       |   25 +++++++++++++++++++++++++
>  qapi-schema.json |   21 +++++++++++++++++++++
>  qmp-commands.hx  |   31 +++++++++++++++++++++++++++++++
>  3 files changed, 77 insertions(+), 0 deletions(-)
> 
> diff --git a/blockdev.c b/blockdev.c
> index aaeb0e8..6a952cd 100644
> --- a/blockdev.c
> +++ b/blockdev.c
> @@ -777,6 +777,31 @@ void qmp_blockdev_snapshot_sync(const char *device, const char *snapshot_file,
>                         &snapshot, errp);
>  }
>  
> +void qmp_blockdev_snapshot_internal_sync(const char *device,
> +                                         bool has_name, const char *name,
> +                                         Error **errp)
> +{
> +    qemu_timeval tv;
> +    struct tm tm;
> +    char name1[128];
> +
> +    BlockdevSnapshotInternal snapshot = {
> +        .device = (char *) device,
> +    };
> +
> +    if (has_name) {
> +        snapshot.name = (char *) name;
> +    } else {
> +        qemu_gettimeofday(&tv);
> +        localtime_r((const time_t *)&tv.tv_sec, &tm);
> +        strftime(name1, sizeof(name1), "vm-%Y%m%d%H%M%S", &tm);
> +        snapshot.name = name1;
> +    }
> +
> +    blockdev_do_action(TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_INTERNAL_SYNC,
> +                       &snapshot, errp);
> +}
> +
>  
>  /* New and old BlockDriverState structs for group snapshots */
>  
> diff --git a/qapi-schema.json b/qapi-schema.json
> index 9e143a8..fd2f8ce 100644
> --- a/qapi-schema.json
> +++ b/qapi-schema.json
> @@ -1689,6 +1689,27 @@
>              '*mode': 'NewImageMode'} }
>  
>  ##
> +# @blockdev-snapshot-internal-sync
> +#
> +# Generates a synchronous internal snapshot of a block device, when the format
> +# of the image used support it.
Confusing to say synchronous internal snapshot, "Synchronously take an
internal snapshot" from below is better. And s/support/supports/.  Maybe
document the return value for unsupported format too?
> +#
> +# @device: the name of the device to generate the snapshot from
> +#
> +# @name: #optional the new snapshot name. If not specified, a name will be
> +# generated according to time by qemu
> +#
> +# Returns: nothing on success
> +#          If @device is not a valid block device, DeviceNotFound
> +#          If any snapshot matching @name exist, or the name is a numeric which
> +#          may mess up with snapshot ID, generic error will be returned
> +#
> +# Since 1.6
> +##
> +{ 'command': 'blockdev-snapshot-internal-sync',
> +  'data': { 'device': 'str', '*name': 'str'} }
> +
> +##
>  # @human-monitor-command:
>  #
>  # Execute a command on the human monitor and return the output.
> diff --git a/qmp-commands.hx b/qmp-commands.hx
> index d31f518..e41e98a 100644
> --- a/qmp-commands.hx
> +++ b/qmp-commands.hx
> @@ -1044,6 +1044,37 @@ Example:
>  EQMP
>  
>      {
> +        .name       = "blockdev-snapshot-internal-sync",
> +        .args_type  = "device:B,name:s?",
> +        .mhandler.cmd_new = qmp_marshal_input_blockdev_snapshot_internal_sync,
> +    },
> +
> +SQMP
> +blockdev-snapshot-internal-sync
> +-------------------------------
> +
> +Synchronously take an internal snapshot of a block device when the format of
> +image used support it.  If name is not specified, it will be automatically
I meant here: This is easier to understand.
s/support/supports/
> +generated by qemu according to host time.  If the name is a numeric string
> +which may mess up with ID, such as "19", the operation will fail.  If a
> +snapshot with name already exist, the operation will fail.
s/exist/exists/
> +
> +Arguments:
> +
> +- "device": device name to snapshot (json-string)
> +- "name": name of the new snapshot (json-string, optional)
> +
> +Example:
> +
> +-> { "execute": "blockdev-snapshot-internal-sync",
> +                "arguments": { "device": "ide-hd0",
> +                               "name": "snapshot0" }
> +   }
> +<- { "return": {} }
> +
> +EQMP
> +
> +    {
>          .name       = "drive-mirror",
>          .args_type  = "sync:s,device:B,target:s,speed:i?,mode:s?,format:s?,"
>                        "on-source-error:s?,on-target-error:s?,"
> -- 
> 1.7.1
> 
> 
> 

-- 
Fam