Re: [PATCH 3/5] ext4: Implement project ID support for ext4 filesystem

[Dmitry Monakhov <dmonakhov@openvz.org>]

Christoph Hellwig <hch@infradead.org> writes:

> On Thu, Mar 04, 2010 at 09:34:35PM +0300, Dmitry Monakhov wrote:
>>   Project id is stored on disk inside xattr usually inside ibody.
>>   Xattr is used only as a data storage, It has not user visible xattr
>>   interface.
>> 
>> * User interface
>>   Project id is accessible via generic xattr interface "system.project_id"
>> 
>> TODO: implement e2libfs support for project_id.
>
> I think you'd be much better off storing it inide the inode core itself.
> E.g. you could ue the never used fragment address in the ext2/3/4 disk
> inode.http://patchwork.ozlabs.org/patch/38766
This was already discussed at the first RFC
http://patchwork.ozlabs.org/patch/38766
and Andreas was strongly against this idea.
>
>> +#ifdef CONFIG_QUOTA
>> +	qid[PRJQUOTA] = new_prjid;
>> +	ret = inode->i_sb->dq_op->transfer(inode, qid, 1 << PRJQUOTA);
>> +	if (ret)
>> +		return ret;
>> +#endif
>
> This needs to be updated to use dquot_transfer directly.