Re: [PATCH 08/14] NFSv4: Add label recommended attribute and NFSv4flags

From: James Morris
Date: Fri Apr 03 2009 - 04:33:36 EST


On Wed, 26 Nov 2008, David P. Quigley wrote:

> diff --git a/include/linux/nfs4.h b/include/linux/nfs4.h
> index ea03667..144eacf 100644
> --- a/include/linux/nfs4.h
> +++ b/include/linux/nfs4.h
> @@ -21,6 +21,7 @@
> #define NFS4_FHSIZE 128
> #define NFS4_MAXPATHLEN PATH_MAX
> #define NFS4_MAXNAMLEN NAME_MAX
> +#define NFS4_MAXLABELLEN 4096

I can't recall if this has been discussed before, but why is the label
length limited to this value?

SELinux on-disk labels can be up to 64KB in size (XATTR_SIZE_MAX), and I'd
like to ensure that we don't end up with an unnecessary disk vs. network
label size incompatibility.

While it seems unlikely that SELinux (and other forms of MAC) security
labels would currently exceed 4K, we don't know how SELinux might be
extended in the future, and should avoid limiting label flexibility
beyond existing constraints.


- James
--
James Morris
<jmorris@xxxxxxxxx>
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