2010-06-04 18:25:07

by Christoph Hellwig

[permalink] [raw]
Subject: Re: [pnfs] [PATCH 3/3] pnfs-blocklayout client: add block device pipe processing based on simple rpc pipefs

Btw, simple reminder that all this has zero chance of going upstream
until someone addresses the issue of a proper API for locking down the
device mappings and getting the final block mapping in kernelspace.



2010-06-09 00:12:36

by J. Bruce Fields

[permalink] [raw]
Subject: Re: [pnfs] [PATCH 3/3] pnfs-blocklayout client: add block device pipe processing based on simple rpc pipefs

On Fri, Jun 04, 2010 at 02:25:06PM -0400, Christoph Hellwig wrote:
> Btw, simple reminder that all this has zero chance of going upstream
> until someone addresses the issue of a proper API for locking down the
> device mappings and getting the final block mapping in kernelspace.

Do you have any more details on the issue? (Reference to a previous
thread?)

My (probably faulty) understanding of the the basic idea of the patches:
a list of block signatures and a description of the desired topology is
passed up to a userspace daemon, and the daemon cobbles together a
device and passes down device major/minor numbers for the result.

Are major/minor numbers the right way to hand off the device? (And what
do you mean by "locking down the device mappings"? Is there a
possibility the device can be destroyed while the kernel's using it?)

--b.

2010-06-04 18:31:37

by Sorin Faibish

[permalink] [raw]
Subject: Re: [pnfs] [PATCH 3/3] pnfs-blocklayout client: add block device pipe processing based on simple rpc pipefs

On Fri, 04 Jun 2010 14:25:06 -0400, Christoph Hellwig <[email protected]=
g> =20
wrote:

> Btw, simple reminder that all this has zero chance of going upstream
> until someone addresses the issue of a proper API for locking down th=
e
> device mappings and getting the final block mapping in kernelspace.
Remember our discussion of 2 years ago. :)

>
>
>



--=20
Best Regards

Sorin Faibish
Corporate Distinguished Engineer
Network Storage Group

EMC=B2
where information lives

Phone: 508-435-1000 x 48545
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Email : [email protected]