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Date: Mon, 16 Mar 2015 15:51:01 +0100
From: Paolo Bonzini <pbonzini@redhat.com>
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Subject: Re: [Qemu-devel] [PATCH 20/25] block/nbd: Comment on discard/flush
	silently failing
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To: Max Reitz <mreitz@redhat.com>, qemu-block@nongnu.org
Cc: Kevin Wolf <kwolf@redhat.com>, qemu-devel@nongnu.org, Stefan Hajnoczi <stefanha@redhat.com>



On 16/03/2015 15:49, Max Reitz wrote:
>>>
>> Right, but a better model than block.c should be for example
>> block/raw-posix.c, which returns ENOTSUP (I checked now...).
> 
> Maybe we should catch ENOTSUP in bdrv_co_discard() and override it?

That's what it does:

        if (ret && ret != -ENOTSUP) {
            return ret;
        }

Returning 0 for NBD's flush_to_disk, by the way, is okay.

Paolo