Re: [PATCH v3] xfs: add check before calling xfs_mod_fdblocks

[Stephen Zhang]

> I understand that calling __xfs_ag_resv_init on an AG with a maximally
> sized data structure can result in @hidden_space being zero here, but
> why does that matter enough to change the code?  Are you experiencing
> problems when this happens?  Unnecessary slowdowns at mount time?
> Something else?
>
> This is v3 of a patch and I still can't tell why I should care ...?

After applying this patch, we can avoid to call xfs_mod_fdblocks when
delta equals 0. So we can reduce unnecessary operations here.