Re: [PATCH 0/5] block: loop: add file format subsystem and QCOW2 file format driver

From: Manuel Bentele <manuel-bentele@web.de>
To: Bart Van Assche <bvanassche@acm.org>,
	development@manuel-bentele.de, linux-block@vger.kernel.org
Subject: Re: [PATCH 0/5] block: loop: add file format subsystem and QCOW2 file format driver
Date: Sat, 24 Aug 2019 11:14:20 +0200	[thread overview]
Message-ID: <4cc02259-24c0-0858-5439-5b1b0649d4f2@web.de> (raw)
In-Reply-To: <da0a76ae-0627-24b8-1aa5-62463e8b3759@acm.org>

Hi Bart

Thanks for your quick reply.

On 8/24/19 5:37 AM, Bart Van Assche wrote:
> On 8/23/19 3:56 PM, development@manuel-bentele.de wrote:
>> During the discussion, it turned out that the implementation as device
>> mapper target is not applicable. The device mapper stacks different
>> functionality such as compression or encryption on multiple block device
>> layers whereas an implementation for the QCOW2 container format provides
>> these functionalities on one block device layer.
>
> Hi Manuel,
>
> Is there a more detailed discussion available of this subject?
No, the only discussion is the referenced one [1]. But there was a
similar discussion in the master's thesis of Francesc Zacarias Ribot
[2]. Unfortunately, I found no attempt on the mailing list that proposes
his solution.

> Are you familiar with the dm-crypt driver?
I don't know the specific implementation details, but I use this driver
personally and I like it. Do you want to propose that only the storage
aspect of the QCOW2 container format should be used and all other
functionality inside the container should be provided by available
device mapper targets?

> [...]

Regards,
Manuel

[1] https://www.spinics.net/lists/linux-block/msg39538.html
[2] Francesc Zacarias Ribot: QLOOP Linux driver to mount QCOW2 virtual
disks; June 23, 2010;
https://upcommons.upc.edu/bitstream/handle/2099.1/9619/65757.pdf