Re: [Ocfs2-devel] [PATCH 13/39] ocfs2: Add extended attribute support

Christoph Hellwig
2008-10-08T13:35:28Z

On Wed, Oct 08, 2008 at 09:56:41AM +0800, Tiger Yang wrote:
> I have looked the patch for btrfs about this. We are different.
> Btrfs store the whole xattr name including the prefix "user."
> "trusted.", we store index number instead of it.

I looked at the git tree and there are two users of
ocfs2_xattr_handler().

(1) for using the ->list handler in listattr. That's something I fixed
in btrfs that I wanted to point you to. The whole concept of a
->list handler is stupid, and it was only added as a hack for
the tmpfs "generic" xattr support which is a mess. Instead of
looking up a handler that would only do the same thing anyway
for all on-disk attributes just call the code directly and
have a map from index to prefix (look at
fs/xfs/linux-2.6/xfs_xattr.c for an example). You
also have a check for OCFS2_MOUNT_NOUSERXATTR for the user
attributes, but that's much easier done by just checking the
index in an if (and I'd personally just kill it completely, the
options doesn't seem useful - but that's an unrelated bit)

(2) For generating the hash. I don't quite understand why you want to
also hash the prefix if it's not store on disk anyway but sorted
into the numeric buckets.