From: Jan Kara <jack@suse.cz>
To: Dmitry Monakhov <dmonakhov@openvz.org>
Cc: linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org
Subject: Re: [PATCH 4/5] ext4: add isolated project support
Date: Thu, 4 Mar 2010 21:07:00 +0100 [thread overview]
Message-ID: <20100304200700.GA6092@atrey.karlin.mff.cuni.cz> (raw)
In-Reply-To: <1267727677-11956-5-git-send-email-dmonakhov@openvz.org>
Hi,
> PROJECT_ISOLATION
> This feature allows to create an isolated project subtrees.
> Isolation means what:
> 1) directory subtree has no common inodes (no hadlinks across subtrees)
> 2) All descendants belongs to the same subtree.
>
> Project subtree's isolation assumptions:
> 1)Inode can not belongs to different subtree trees
> Otherwise changes in one subtree result in changes in other subtree
> which contradict to isolation criteria.
Just a curious question:
Do you really need this subtree separation in your envisioned containers
usecase? Because there I imagine you have one project_id per container,
containers form disjoint subtrees (at least their writeable parts) and
each file & directory has this project_id set and you forbid to manipulate
project id's from inside the container (otherwise you'd have problems with
enforcing quota limits I guess).
And when project_id is a per-inode property, quota has no problems with it
(is well defined) even without subtree separation. So is this subtree
separation really needed?
Honza
--
Jan Kara <jack@suse.cz>
SuSE CR Labs
next prev parent reply other threads:[~2010-03-04 20:07 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-03-04 18:34 [PATCH 0/5] RFC: introduce extended inode owner identifier v5 Dmitry Monakhov
2010-03-04 18:34 ` [PATCH 1/5] vfs: Add additional owner identifier Dmitry Monakhov
2010-03-04 18:34 ` [PATCH 2/5] quota: Implement project id support for generic quota Dmitry Monakhov
2010-03-04 18:34 ` [PATCH 3/5] ext4: Implement project ID support for ext4 filesystem Dmitry Monakhov
2010-03-04 18:34 ` [PATCH 4/5] ext4: add isolated project support Dmitry Monakhov
2010-03-04 18:34 ` [PATCH 5/5] ext4: add project quota support Dmitry Monakhov
2010-03-04 20:07 ` Jan Kara [this message]
2010-03-04 20:34 ` [PATCH 4/5] ext4: add isolated project support Dmitry Monakhov
2010-03-11 12:07 ` Christoph Hellwig
2010-03-11 12:06 ` [PATCH 3/5] ext4: Implement project ID support for ext4 filesystem Christoph Hellwig
2010-03-11 13:30 ` Dmitry Monakhov
2010-03-11 19:54 ` Andreas Dilger
2010-03-11 22:01 ` tytso
2010-03-12 9:32 ` Dmitry Monakhov
2010-03-12 20:07 ` J. Bruce Fields
2010-03-11 12:03 ` [PATCH 2/5] quota: Implement project id support for generic quota Christoph Hellwig
2010-03-11 13:17 ` Dmitry Monakhov
2010-03-11 12:01 ` [PATCH 1/5] vfs: Add additional owner identifier Christoph Hellwig
2010-03-11 13:11 ` Dmitry Monakhov
2010-03-11 18:51 ` J. Bruce Fields
2010-03-11 19:40 ` Andreas Dilger
2010-03-12 8:47 ` Dmitry Monakhov
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