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Date:   Thu, 13 Jun 2019 09:52:42 -0400
From:   Josef Bacik <josef@toxicpanda.com>
To:     roman.stratiienko@globallogic.com
Cc:     linux-kernel@vger.kernel.org, josef@toxicpanda.com,
        nbd@other.debian.org, A.Bulyshchenko@globallogic.com,
        linux-block@vger.kernel.org, axboe@kernel.dkn.org
Subject: Re: [PATCH 2/2] nbd: add support for nbd as root device
Message-ID: <20190613135241.aghcrrz7rg2au3bw@MacBook-Pro-91.local>
References: <20190612163144.18486-1-roman.stratiienko@globallogic.com>
 <20190612163144.18486-2-roman.stratiienko@globallogic.com>
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On Wed, Jun 12, 2019 at 07:31:44PM +0300, roman.stratiienko@globallogic.com wrote:
> From: Roman Stratiienko <roman.stratiienko@globallogic.com>
> 
> Adding support to nbd to use it as a root device. This code essentially
> provides a minimal nbd-client implementation within the kernel. It opens
> a socket and makes the negotiation with the server. Afterwards it passes
> the socket to the normal nbd-code to handle the connection.
> 
> The arguments for the server are passed via kernel command line.
> The kernel command line has the format
> 'nbdroot=[<SERVER_IP>:]<SERVER_PORT>/<EXPORT_NAME>'.
> SERVER_IP is optional. If it is not available it will use the
> root_server_addr transmitted through DHCP.
> 
> Based on those arguments, the connection to the server is established
> and is connected to the nbd0 device. The rootdevice therefore is
> root=/dev/nbd0.
> 
> Patch was initialy posted by Markus Pargmann <mpa@pengutronix.de>
> and can be found at https://lore.kernel.org/patchwork/patch/532556/
> 
> Change-Id: I78f7313918bf31b9dc01a74a42f0f068bede312c
> Signed-off-by: Roman Stratiienko <roman.stratiienko@globallogic.com>
> Reviewed-by: Aleksandr Bulyshchenko <A.Bulyshchenko@globallogic.com>

Just throw nbd-client in your initramfs.  Every nbd server has it's own
handshake protocol, embedding one particular servers handshake protocol into the
kernel isn't the answer here.  Thanks,

Josef