Re: [PATCH 1/2] fs: Do not dispatch FITRIM through separate super_operation

Matthew Wilcox
2010-11-18T14:20:01Z

On Thu, Nov 18, 2010 at 08:48:04AM -0500, Josef Bacik wrote:
> On Thu, Nov 18, 2010 at 06:06:30AM -0700, Matthew Wilcox wrote:
> > On Thu, Nov 18, 2010 at 08:36:48AM +0100, Lukas Czerner wrote:
> > > There was concern that FITRIM ioctl is not common enough to be included
> > > in core vfs ioctl, as Christoph Hellwig pointed out there's no real point
> > > in dispatching this out to a separate vector instead of just through
> > > ->ioctl.
> >
> > Um, are you and Josef working independently of each other? You don't
> > seem to be cc'ing each other on your patches, and you're basically doing
> > the same thing.
> >
>
> I guess they are the same thing in that we're both dealing with free'ing up
> space, but thats about where the similarities end. Lukas' work is in TRIM'ing
> already free'd space, mine is in creating free'd space. Plus I don't know
> anything nor wish to ever know anything about TRIM ;). Thanks,

I guess I was assuming that, on receiving a FALLOC_FL_PUNCH_HOLE, a
filesystem that was TRIM-aware would pass that information down to the
block device that it's mounted on. I strongly feel that we shouldn't
have two interfaces to do essentially the same thing.

I guess I'm saying that you're going to have to learn about TRIM :-)

--
Matthew Wilcox Intel Open Source Technology Centre
"Bill, look, we understand that you're interested in selling us this
operating system, but compare it to ours. We can't possibly take such
a retrograde step."