Re: [PATCH 7/7][TAKE5] ext4: support new modes

Amit K. Arora
2007-06-28T18:07:54Z

On Wed, Jun 27, 2007 at 10:04:56AM +1000, David Chinner wrote:
> On Wed, Jun 27, 2007 at 12:59:08AM +0530, Amit K. Arora wrote:
> > On Tue, Jun 26, 2007 at 12:14:00PM -0400, Andreas Dilger wrote:
> > > On Jun 26, 2007 17:37 +0530, Amit K. Arora wrote:
> > > > I think, modifying ctime/mtime should be dependent on the other flags.
> > > > E.g., if we do not zero out data blocks on allocation/deallocation,
> > > > update only ctime. Otherwise, update ctime and mtime both.
> > >
> > > I'm only being the advocate for requirements David Chinner has put
> > > forward due to existing behaviour in XFS. This is one of the reasons
> > > why I think the "flags" mechanism we now have - we can encode the
> > > various different behaviours in any way we want and leave it to the
> > > caller.
> >
> > I understand. May be we can confirm once more with David Chinner if this
> > is really required. Will it really be a compatibility issue if new XFS
> > preallocations (ie. via fallocate) update mtime/ctime?
>
> It should be left up to the filesystem to decide. Only the
> filesystem knows whether something changed and the timestamp should
> or should not be updated.

Since Andreas had suggested FA_FL_NO_MTIME flag thinking it as a
requirement from XFS (whereas XFS does not need this flag), I don't think
we need to add this new flag.

Please let know if someone still feels FA_FL_NO_MTIME flag can be
useful.

--
Regards,
Amit Arora