Re: [PATCH 4/6] libfrog: create online fs geometry converters

From: "Darrick J. Wong" <darrick.wong@oracle.com>
To: Dave Chinner <david@fromorbit.com>
Cc: sandeen@sandeen.net, linux-xfs@vger.kernel.org
Subject: Re: [PATCH 4/6] libfrog: create online fs geometry converters
Date: Wed, 28 Aug 2019 10:35:34 -0700	[thread overview]
Message-ID: <20190828173534.GG1037350@magnolia> (raw)
In-Reply-To: <20190827071106.GD1119@dread.disaster.area>

On Tue, Aug 27, 2019 at 05:11:06PM +1000, Dave Chinner wrote:
> On Tue, Aug 20, 2019 at 01:30:57PM -0700, Darrick J. Wong wrote:
> > From: Darrick J. Wong <darrick.wong@oracle.com>
> > 
> > Create helper functions to perform unit conversions against a runtime
> > filesystem, then remove the open-coded versions in scrub.
> 
> .... and there they are...
> 
> > +/* Convert fs block number into bytes */
> > +static inline uint64_t
> > +xfrog_fsb_to_b(
> > +	const struct xfs_fd	*xfd,
> > +	uint64_t		fsb)
> > +{
> > +	return fsb << xfd->blocklog;
> > +}
> 
> FWIW, this is for converting linear offsets in fsb /units/, not the
> sparse fsbno (= agno | agbno) to bytes. I've always found it a bit
> nasty that this distinction is not clearly made in the core FSB
> conversion macros.
> 
> perhaps off_fsb_to_b?

Ok to both.

--D

> > +/* Convert bytes into (rounded down) fs block number */
> > +static inline uint64_t
> > +xfrog_b_to_fsbt(
> > +	const struct xfs_fd	*xfd,
> > +	uint64_t		bytes)
> > +{
> > +	return bytes >> xfd->blocklog;
> > +}
> 
> Ditto.
> 
> Otherwise looks ok.
> 
> Cheers,
> 
> Dave.
> -- 
> Dave Chinner
> david@fromorbit.com