Dennis Gilmore wrote:
On Tuesday 20 March 2007 11:00:14 am Warren Togami wrote:
NOTE: This info is not relevant to the near-term Fedora merge or any
infrastructure supporting it. We will continue to use the existing CVS
+ ACL system.
Toshio was wondering about the possibility of using filesystem ACL's as
part of a future ideal SCM's ACL enforcement. It would work something
like this:
1) PackageDB knows about all packages, owners, granted permissions,
groups, etc.
2) PackageDB generates xattrs or FS ACL (themselves based on xattrs)
within the SCM files/directories.
3) SCM has a custom ACL enforcement script that reads those xattrs,
making it very fast and flexible. ACL's could be enforced based on a
list of users, groups, or a combination of users and groups.
Sounds very sane to me
I talked with a few filesystem experts within Red Hat. They said...
- ext3 has a limit of 4KB for xattr data. If you use the standard
encoding of 8 bytes per uid, that has a limit of roughly 100 entities
that could be associated with a file. Is this too limiting? I dunno.
Perhaps it need not be too limiting if more extensive use of
group-based-ACL's are used.
I would like to encourage use of acls based on groups extensivly. i.e KDE SIG
security etc. 8KB would probably be a little better but 4KB will be fine.
- XFS could possibly allow a maximum of 64KB xattr's per file, but that
is very inefficient in filesystem storage.
- xattr's are currently not supported by NFS.
i currently use linux ACL's over nfs very effectively
I forgot to mention this to the list but we are currently using ACL's
effectively with the docs team. Basically all the translators have
access to the doc's cvs /cvs/docs/*/po/ using the extended acls. I have
a script that runs regularly that sets up these perms.
-Mike
