From mboxrd@z Thu Jan  1 00:00:00 1970
From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Subject: Re: Trigger xen_vbd_resize
Date: Thu, 15 Aug 2013 16:18:18 -0400
Message-ID: <20130815201817.GE5337@konrad-lan.dumpdata.com>
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To: Steve Prochniak <steve.prochniak@oracle.com>
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On Thu, Aug 15, 2013 at 09:03:11AM -0700, Steve Prochniak wrote:
> I can see that there is support for dynamically resizing of virtual disks in blockback, but how do I trigger backend_changed->xen_blkif_schedule->xen_vbd_resize() when I use something like dd to expand my file backed storage?

That would imply you are using the loop back device. If you look in the
blkback driver you will see that it checks on every request that:

#define vbd_sz(_v)      ((_v)->bdev->bd_part ? \
                         (_v)->bdev->bd_part->nr_sects : \
                          get_capacity((_v)->bdev->bd_disk))

And if you follow get_capacity, you get to:

static inline sector_t get_capacity(struct gendisk *disk)
{
        return disk->part0.nr_sects;
}

Looking in the loop device.. well, I will let you figure this out -
hint: figure_loop_size


> 
>  

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