2010-06-08 16:02:25

by Will Drewry

[permalink] [raw]
Subject: Re: [PATCH 2/2] init, mount: export the name_to_dev_t symbol

On Tue, May 25, 2010 at 1:30 PM, Mike Snitzer <[email protected]> wrote:
> On Tue, May 25 2010 at ?1:21pm -0400,
> Christoph Hellwig <[email protected]> wrote:
>
>> On Tue, May 25, 2010 at 11:11:33AM -0500, Will Drewry wrote:
>> > In addition to getting rid of the code duplication, I'd like device-mapper
>> > to be able to resolve slave devices at boot-time to accommodate a
>> > do_mounts_dm.c equivalent to do_mounts_md.c:
>>
>> So please add a do_mounts_dm.c instead of pushing this somewhere it
>> doesn't belong to.
>
> He is proposing doing just that, you cut out the patchwork url he
> already shared: https://patchwork.kernel.org/patch/101024/
>
> Will's intentions are good: avoid code duplication.
>
> He is also trying to keep DM-specific common code in drivers/md/
>
> So in this instance, avoiding the need to export name_to_dev_t would
> require splitting the internal DM __table_get_device (or more likely:
> dm_get_device) out to a public facing interface that takes a dev_t.

FWIW, I mailed out a new patchset which does not expect the dm core
code to understand device paths before there is a root device. Now it
walks the target parameters supplied to do_mounts_dm.c and attempts
a best-guess replacement with major:minor numbers. It's not as succinct,
but it achieves the isolation requested and negates the need for the
patch on this thread.

The relevant init-time patchwork link:
https://patchwork.kernel.org/patch/104861/
(Full patchset is 58-61)

Any and all comments will be appreciated - thanks!
will