linux-ext4 - Re: [PATCH -V4 00/11] New ACL format for better NFSv4 acl interoperability

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Message-ID: <20101012002409.GH16442@fieldses.org>
Date:	Mon, 11 Oct 2010 20:24:09 -0400
From:	"J. Bruce Fields" <bfields@...i.umich.edu>
To:	"Aneesh Kumar K.V" <aneesh.kumar@...ux.vnet.ibm.com>
Cc:	sfrench@...ibm.com, ffilz@...ibm.com, agruen@...e.de,
	adilger@....com, sandeen@...hat.com, tytso@....edu,
	jlayton@...hat.com, linux-fsdevel@...r.kernel.org,
	nfsv4@...ux-nfs.org, linux-ext4@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH -V4 00/11]  New ACL format for better NFSv4 acl
 interoperability

On Fri, Sep 24, 2010 at 06:18:03PM +0530, Aneesh Kumar K.V wrote:
> 
> Hi,
> 
> The following set of patches implements VFS changes needed to implement
> a new acl model for linux. Rich ACLs are an implementation of NFSv4 ACLs,
> extended by file masks to fit into the standard POSIX file permission model.
> They are designed to work seamlessly locally as well as across the NFSv4 and
> CIFS/SMB2 network file system protocols.
> 
> The patch set consists of four parts:
> 
> The first set of patches, posted as a follow up, contains VFS changes needed
> to implement the Rich ACL model. The second set [1] contains the Rich ACL model
> and Ext4 implementation. The third set [2] contains mapping of Rich ACL to
> NFSv4 ACL (how to apply file mask to access mask) and implementation of
> Richacl ACL for NFS server and client.

That's the part I'd like to review carefully and haven't yet.

> The fourth set [3] contains POSIX ACL
> to Rich ACL mapping and its ext4 usage.

The one thing I remember not liking before was a flag that told the user
whether a given ACL was originally mapped from POSIX or not.  Is that
still there?

Overall I'm for doing this: I don't like NFSv4/Windows ACLs more than
anyone else, but they're too useful to ignore, and the mapping that
Samba and the NFSv4 server try to do is painful for users.

--b.

> 
> [1] git://git.kernel.org/pub/scm/linux/kernel/git/agruen/linux-2.6-richacl.git richacl-minimal
> [2] git://git.kernel.org/pub/scm/linux/kernel/git/agruen/linux-2.6-richacl.git richacl-upstream
> [3] git://git.kernel.org/pub/scm/linux/kernel/git/agruen/linux-2.6-richacl.git richacl-fullset
> 
> A user-space utility for displaying and changing richacls is available at [4]
> (a number of examples can be found at http://acl.bestbits.at/richacl/examples.html).
> 
> [4] git://git.kernel.org/pub/scm/linux/kernel/git/agruen/richacl.git master
> 
> To test richacl on ext4 use -o richacl mount option. This mount option may later be
> dropped in favour of a feature flag.
> 
> More details regarding richacl can be found at 
> http://acl.bestbits.at/richacl/
> 
> Changes from V3:
> a) Droped may_delete and may_create inode operations callback and reworked
>    the patch series to use additional check flags. 
> b) Rebased to the latest kernel
> c) The patch series now contain only the minimal VFS changes.
> 
> Changes from V2:
> 1) Git repo include check-acl branch that drop newly added inode_operations
>    callback in favour for additional access check flags (MAY_CREATE_FILE,
>    MAY_CREATE_DIR, MAY_DELETE_CHILD, MAY_DELETE_SELF, MAY_TAKE_OWNERSHIP,
>    MAY_CHMOD, and MAY_SET_TIMES)
> 2) richacl is now cached in the vfs inode instead of file system inode.
>    (currently kept as a separate patch. We may want to fold that later)
> 3) Added a new acl flag ACL4_MASKED. richacl_apply_masks() can skip transforming acls
>    without this flag, which speeds things up and avoids modifying those acls unnecessarily.
> 4) Owner always allowed permissions are now explicitly included when synthesizing an acl
>    from file mode.
> 
> Changes from V1:
> 1) Split the patches into smaller patches
> 2) Added extensive documentation to the patches.
> 
> -aneesh
> 
> 
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