Re: [Qemu-devel] [PATCH V5 05/13] block: add image info query function bdrv_query_image_info()

[Wenchao Xia]

于 2013-1-29 20:55, Kevin Wolf 写道:
> Am 24.01.2013 03:57, schrieb Wenchao Xia:
> >    This patch add function bdrv_query_image_info(), which will return
> > image info in qmp object format. The implementation code are mostly
> > copied from qemu-img.c, but use block layer function to get snapshot
> > info.
>
> Don't copy code, reuse it.
>
> Can you move the existing qemu-img code to block.c and make qemu-img use
> it from there?
  A bit hard, original code are adjusted to form two API:image_info and
snapshot info. Those code can be moved to block.c in one patch and
in following patch modified, if you like.

> >    A check with bdrv_can_read_snapshot(), was done before collecting
> > snapshot info.
> >
> > Signed-off-by: Wenchao Xia <address@hidden>
> > Reviewed-by: Eric Blake <address@hidden>
> > ---
> >   block.c               |   73 +++++++++++++++++++++++++++++++++++++++++++++++++
> >   include/block/block.h |    1 +
> >   2 files changed, 74 insertions(+), 0 deletions(-)
> >
> > diff --git a/block.c b/block.c
> > index 7cdb6c6..14bf653 100644
> > --- a/block.c
> > +++ b/block.c
> > @@ -2902,6 +2902,79 @@ SnapshotInfoList 
> > *bdrv_query_snapshot_infolist(BlockDriverState *bs,
> >       return head;
> >   }
> >
> > +/* collect all internal snapshot info in a image for ImageInfo */
> > +static void collect_snapshots_info(BlockDriverState *bs,
> > +                                   ImageInfo *info,
> > +                                   Error **errp)
> > +{
> > +    SnapshotInfoList *info_list;
> > +
> > +    if (!bdrv_can_read_snapshot(bs)) {
> > +        return;
> > +    }
> > +    info_list = bdrv_query_snapshot_infolist(bs, NULL, NULL, errp);
> > +    if (info_list != NULL) {
> > +        info->has_snapshots = true;
> > +        info->snapshots = info_list;
> > +    }
> > +}
> > +
> > +static void collect_image_info(BlockDriverState *bs,
> > +                               ImageInfo *info)
> > +{
> > +    uint64_t total_sectors;
> > +    char backing_filename[1024];
> > +    char backing_filename2[1024];
> > +    BlockDriverInfo bdi;
> > +    const char *filename;
> > +
> > +    filename = bdrv_get_filename(bs);
> > +    bdrv_get_geometry(bs, &total_sectors);
> > +
> > +    info->filename        = g_strdup(filename);
> > +    info->format          = g_strdup(bdrv_get_format_name(bs));
> > +    info->virtual_size    = total_sectors * 512;
> > +    info->actual_size     = bdrv_get_allocated_file_size(bs);
> > +    info->has_actual_size = info->actual_size >= 0;
> > +    if (bdrv_is_encrypted(bs)) {
> > +        info->encrypted = true;
> > +        info->has_encrypted = true;
> > +    }
> > +    if (bdrv_get_info(bs, &bdi) >= 0) {
> > +        if (bdi.cluster_size != 0) {
> > +            info->cluster_size = bdi.cluster_size;
> > +            info->has_cluster_size = true;
> > +        }
> > +        info->dirty_flag = bdi.is_dirty;
> > +        info->has_dirty_flag = true;
> > +    }
> > +    bdrv_get_backing_filename(bs, backing_filename, sizeof(backing_filename));
>
> No need to copy this, you can directly access bs->backing_file.
  OK.

> Kevin


--
Best Regards

Wenchao Xia