Re: [PATCH 2/6] libfrog: introduce xfs_fd to wrap an fd to a file on an xfs filesystem

[Dave Chinner <david@fromorbit.com>]

On Tue, Aug 20, 2019 at 01:30:44PM -0700, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@oracle.com>
> 
> Introduce a new "xfs_fd" context structure where we can store a file
> descriptor and all the runtime fs context (geometry, which ioctls work,
> etc.) that goes with it.  We're going to create wrappers for the
> bulkstat and inumbers ioctls in subsequent patches; and when we
> introduce the v5 bulkstat/inumbers ioctls we'll need all that context to
> downgrade gracefully on old kernels.  Start the transition by adopting
> xfs_fd natively in scrub.
> 
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> ---
>  include/xfrog.h    |   20 ++++++++++++++++++++

naming.

>  libfrog/fsgeom.c   |   25 +++++++++++++++++++++++++
>  scrub/fscounters.c |   22 ++++++++++++----------
>  scrub/inodes.c     |   10 +++++-----
>  scrub/phase1.c     |   41 ++++++++++++++++++++---------------------
>  scrub/phase2.c     |    2 +-
>  scrub/phase3.c     |    4 ++--
>  scrub/phase4.c     |    8 ++++----
>  scrub/phase5.c     |    2 +-
>  scrub/phase6.c     |    6 +++---
>  scrub/phase7.c     |    2 +-
>  scrub/repair.c     |    4 ++--
>  scrub/scrub.c      |   12 ++++++------
>  scrub/spacemap.c   |   12 ++++++------
>  scrub/vfs.c        |    2 +-
>  scrub/xfs_scrub.h  |    7 ++++---
>  16 files changed, 113 insertions(+), 66 deletions(-)
> 
> 
> diff --git a/include/xfrog.h b/include/xfrog.h
> index 5420b47c..f3808911 100644
> --- a/include/xfrog.h
> +++ b/include/xfrog.h
> @@ -19,4 +19,24 @@
>  struct xfs_fsop_geom;
>  int xfrog_geometry(int fd, struct xfs_fsop_geom *fsgeo);
>  
> +/*
> + * Structure for recording whatever observations we want about the level of
> + * xfs runtime support for this fd.  Right now we only store the fd and fs
> + * geometry.
> + */
> +struct xfs_fd {
> +	/* ioctl file descriptor */
> +	int			fd;
> +
> +	/* filesystem geometry */
> +	struct xfs_fsop_geom	fsgeom;
> +};
> +
> +/* Static initializers */
> +#define XFS_FD_INIT(_fd)	{ .fd = (_fd), }
> +#define XFS_FD_INIT_EMPTY	XFS_FD_INIT(-1)
> +
> +int xfrog_prepare_geometry(struct xfs_fd *xfd);
> +int xfrog_close(struct xfs_fd *xfd);

I'd much prefer to see these named xfd_prepare_geometry() and
xfd_close()...

>  	ci = calloc(1, sizeof(struct xfs_count_inodes) +
> -			(ctx->geo.agcount * sizeof(uint64_t)));
> +			(ctx->mnt.fsgeom.agcount * sizeof(uint64_t)));

This gets a bit verbose, but.... <shrug> .... doesn't make that much
of a mess...

Ok, apart from the naming thing, this looks ok.

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com