[PATCH 12/48] xfs: add CRC checking to dir2 leaf blocks

[Ben Myers]

On Fri, Jun 07, 2013 at 10:25:35AM +1000, Dave Chinner wrote:
> From: Dave Chinner <dchinner at redhat.com>
> 
> This addition follows the same pattern as the dir2 block CRCs.
> Seeing as both LEAF1 and LEAFN types need to changed at the same
> time, this is a pretty large amount of change. leaf block headers
> need to be abstracted away from the on-disk structures (struct
> xfs_dir3_icleaf_hdr), as do the base leaf entry locations.
> 
> This header abstract allows the in-core header and leaf entry
> location to be passed around instead of the leaf block itself. This
> saves a lot of converting individual variables from on-disk format
> to host format where they are used, so there's a good chance that
> the compiler will be able to produce much more optimal code as it's
> not having to byteswap variables all over the place.
> 
> Signed-off-by: Dave Chinner <dchinner at redhat.com>

Looks good.  Note that xfs_dir3_leafn_read_verify and
xfs_dir3_leafn_write_verify are static in the kernel but not in userspace.  

Reviewed-by: Ben Myers <bpm at sgi.com>