No subject

#define XFS_ACL_MAX_ENTRIES 25
....
/* On-disk XFS access control list structure */
struct xfs_acl {
	__be32	  acl_cnt;
	struct xfs_acl_entry {
		__be32  ae_tag;
		__be32  ae_id;
		__be16  ae_perm;
	} acl_entry[XFS_ACL_MAX_ENTRIES];
};

It's basically a limitation of the on-disk format definition that
has been carried over from Irix. It is an arbitrary limit - the real
limit is the maximum size of an attribute (64KB) and we plan to
raise it to that limit as part of the upcoming on-disk format
changes for metadata checksums...

Cheers,

Dave.
-- 
Dave Chinner
david at fromorbit.com