Re: [PATCH 8/9] xfs: add fsgeom flag for v5 superblock support.

Ben Myers
2013-05-29T21:47:03Z

On Wed, May 29, 2013 at 04:43:01PM -0500, Ben Myers wrote:
> Hi Eric,
>
> On Wed, May 29, 2013 at 10:10:13AM -0500, Eric Sandeen wrote:
> > On 5/27/13 1:38 AM, Dave Chinner wrote:
> > > From: Dave Chinner <dchinner@redhat.com>
> > >
> > > Currently userspace has no way of determining that a filesystem is
> > > CRC enabled. Add a flag to the XFS_IOC_FSGEOMETRY ioctl output to
> > > indicate that the filesystem has v5 superblock support enabled.
> > > This will allow xfs_info to correctly report the state of the
> > > filesystem.
> >
> >
> > Looks fine,
> >
> > Reviewed-by: Eric Sandeen <sandeen@redhat.com>
> >
> > Ben, having this in place for for the next point release will let
> > userspace work & testing proceed w/o the need for a patched
> > kernel... if you could consider pulling it in that'd be great.
>
> Sounds reasonable. I'll check it out.
>
> > Dave, just out of curiosity, most other features sort of match between
> > the "_has_*" and the flag names, is there a reason for the
> > crc <-> sbv5 difference? Just semantics, but just curious.
> >
> > (i.e. xfs_sb_version_hasprojid32bit checks XFS_SB_VERSION2_PROJID32BIT,
> > but xfs_sb_version_hascrc checks XFS_SB_VERSION_5)
> >
> > Answering my own question maybe, I guess SB_VERSION_5 was conceived
> > with crc already in place, so there's no need for a feature flag on
> > top of the sb version, right...?
>
> Seems like we're also out of space in xfs_fsop_geom.flags.

> There may even be
> people who prefer to use v5 super blocks without crcs turned on, so maybe
> conflating the two ideas here is undesireable.

Nevermind. That was silly.