Re: [Qemu-devel] [PATCH v2] virtio-blk: add default serial id

[Eric Blake <eblake@redhat.com>]

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On 09/21/2012 07:30 AM, Dave Young wrote:
> 
> For virtio block device, if user does not specify the serial attribute,
> There will be no serial availabe, this is not convenient for identifying
> the disk.
> 
> Doing something similar to ide disks, add a "VD0000?" default serial
> number if user does not specify it.
> 
> [v1->v2 address comments from Eric Blake]:
> fix spell errors in patch description
> decrease drive_serial in virtio_blk_exit as well

Typically, patch changelogs belong...

> 
> Signed-off-by: Dave Young <dyoung@redhat.com>
> ---

...after the --- line, so that 'git am' doesn't make them part of git
history.  Also, I'm not sure that decreasing the serial number is
correct - you've now made it much easier to get duplicate serial numbers
compared to my original complaint of 100000 hotplug cycles.  Now all I
have to do is:

create a guest with two disks
hot unplug disk one
hot plug a new disk

and voila, both disks will now have serial number 2.

> @@ -632,6 +638,7 @@ VirtIODevice *virtio_blk_init(DeviceStat
>                                            sizeof(struct virtio_blk_config),
>                                            sizeof(VirtIOBlock));
>  
> +    s->drive_serial = drive_serial++;
>      s->vdev.get_config = virtio_blk_update_config;
>      s->vdev.set_config = virtio_blk_set_config;
>      s->vdev.get_features = virtio_blk_get_features;
> @@ -664,4 +671,5 @@ void virtio_blk_exit(VirtIODevice *vdev)
>      unregister_savevm(s->qdev, "virtio-blk", s);
>      blockdev_mark_auto_del(s->bs);
>      virtio_cleanup(vdev);
> +    drive_serial--;
>  }
> 
> 

-- 
Eric Blake   eblake@redhat.com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


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