From mboxrd@z Thu Jan  1 00:00:00 1970
From: Joe Thornber <thornber@redhat.com>
Subject: Re: [PATCH v3] staging: writeboost: Add dm-writeboost
Date: Fri, 20 Feb 2015 16:17:59 +0000
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To: Akira Hayakawa <ruby.wktk@gmail.com>
Cc: ejt@redhat.com, Greg KH <gregkh@linuxfoundation.org>, snitzer@redhat.com, dm-devel@redhat.com, driverdev-devel@linuxdriverproject.org, linux-kernel@vger.kernel.org
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On Sat, Feb 21, 2015 at 01:06:08AM +0900, Akira Hayakawa wrote:
> The size is configurable but typically 512KB (that's the default).
> 
> Refer to bio payload sounds really dangerous but it may be possible
> in some tricky way. but at the moment I am not sure how the
> implementation would be.
> 
> Is there some fancy function that is like memcpy but actually "move"
> the ownership?

When building up your log chunk bio copy the bio_vecs (not the data)
from the original bios.  You can't complete the original bios until
your log chunk has been written.

- Joe