[RFC PATCH 1/4] xfs: introduce a new helper xfs_inobt_reada_chunk()

[Christoph Hellwig]

> > I'd prefer to factor this out even further. xfs_ialloc_inode_init and
> > xfs_ifree_cluster already have two pieces of code that calculate these
> > two (with more readable names) and an additional nuber buffers counter
> > we won't need here, it might make most sense to factor that into a
> > single common helper.
> Yup, I also thought this can be factored out, however, I can not figure out
> a meaningful function name at that time due to my poor skill...
> 
> How about if we introduce an inline helper to xfs_ialloc.h as below?
> 
> /* Helper function to extract the # of blocks/inodes/buffers hint per cluster */
> static inline void
> xfs_ialloc_get_cluster_hints(
> 	struct xfs_mount	*mp,
> 	int			*nblks;
> 	int			*ninodes;
> 	int			*nbufs)
> {
> 	....
> }

Probably fine to make it an inline.  I don't think we need the nbufs
parameter, as it requires the length to calculate, and it's a trivial
length / blks_per_cluster.

Similarly the ninodes value is trivially calculatable, so it might be
as easy as:

static inline int
xfs_ialloc_blks_per_cluster(struct xfs_mount *mp)
{
	if (mp->m_sb.sb_blocksize >= XFS_INODE_CLUSTER_SIZE(mp))
		return 1;
	return XFS_INODE_CLUSTER_SIZE(mp) / mp->m_sb.sb_blocksize;
}


...

	blks_per_cluster = xfs_ialloc_blks_per_cluster(mp);
	nbufs = length / blks_per_cluster;
	ninodes = blks_per_cluster * mp->m_sb.sb_inopblock;