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Date: Mon, 29 Jul 2013 15:56:38 +0200
From: Paolo Bonzini <pbonzini@redhat.com>
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Subject: Re: [Qemu-devel] [PATCH v3 05/19] block: make bdrv_co_is_allocated
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To: Kevin Wolf <kwolf@redhat.com>
Cc: pl@kamp.de, qemu-devel@nongnu.org, stefanha@redhat.com, Charlie Shepherd <charlie@ctshepherd.com>

Il 29/07/2013 15:21, Kevin Wolf ha scritto:
> Am 25.07.2013 um 16:23 hat Paolo Bonzini geschrieben:
>> bdrv_is_allocated can detect coroutine context and go through a fast
>> path, similar to other block layer functions.
>>
>> Reviewed-by: Eric Blake <eblake@redhat.com>
>> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> 
> It can, but why is this a good idea?

What exactly?  Dropping bdrv_co_is_allocated from the public API, or not
creating always a new coroutine while still dropping bdrv_co_is_allocated?

In the end, the answer is simply for consistency.  bdrv_co_is_allocated
is different from all other APIs in this respect, and I didn't want to
choose between making get_block_status the same as is_allocated vs. the
same as everything else.

> Charlie is working in exactly the opposite direction, namely splitting
> the existing functions in a coroutine-only and a synchronous-only part.
> We should be clear what we really want here.

That's fine---but whatever we do we should do it for all APIs.  So this
patch is just making things consistent before adding another API.

Paolo