On Tue, Feb 16, 2010 at 11:56:44AM +0300, Dmitry Monakhov wrote: > what do you mean by "slightly limited" ? > I dont now xfs project-id feature very well. > I cant find good explanation of this feature(except man pages). > Can you please post main design assumptions. The only difference from your subtree quota is that multiple subtrees can belong to a project. XFS project quotas work the following way: - an inode can be marked as belonging to a project, in which case a 32bit project ID is stored in the inode - a flag on the inode is set to inherit the project ID - adding links from outside the subtree is not allowed quota uses the project ID for accounting, similar to the user/group id. One other small difference is that going over the project quota does not return EDQUOT but ENOSPC. > In fact i use get_id in order to support second-level quota feature > *Second-level quota* > In order to isolate user/group quota in one subtree from other subtree > we have to remap quota id similar to: > quota_uid = (subtree_id << 32) | uid; > > And yes, fs-specific quota interfaces are an utter nightmare, speaking > > as the person fixing all this crap up right now. > I've prepare patches against ext4 because: It's perfectly fine to impement it for one filesystem, the important bit is to make sure we have consistant interfaces for it in generic code. I don't think having a get_id callback to allow fs-specific mappings is a good idea for that. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
