On Wed, Oct 11, 2023 at 11:08:03AM -0700, Darrick J. Wong wrote:
> +/* Compute the number of rtsummary blocks needed to track the given rt space. */
> +xfs_filblks_t
> +xfs_rtsummary_blockcount(
> + struct xfs_mount *mp,
> + unsigned int rsumlevels,
> + xfs_extlen_t rbmblocks)
> +{
> + unsigned long long rsumwords;
> +
> + rsumwords = (unsigned long long)rsumlevels * rbmblocks;
> + return XFS_B_TO_FSB(mp, rsumwords << XFS_WORDLOG);
> +}
This helper and its users make complete sense to me and looks good:
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
> +/*
> + * Compute the number of rtsummary info words needed to populate every block of
> + * a summary file that is large enough to track the given rt space.
> + */
> +unsigned long long
> +xfs_rtsummary_wordcount(
> + struct xfs_mount *mp,
> + unsigned int rsumlevels,
> + xfs_extlen_t rbmblocks)
> +{
> + xfs_filblks_t blocks;
> +
> + blocks = xfs_rtsummary_blockcount(mp, rsumlevels, rbmblocks);
> + return XFS_FSB_TO_B(mp, blocks) >> XFS_WORDLOG;
> +}
> @@ -54,8 +55,10 @@ xchk_setup_rtsummary(
> * Create an xfile to construct a new rtsummary file. The xfile allows
> * us to avoid pinning kernel memory for this purpose.
> */
> + wordcnt = xfs_rtsummary_wordcount(mp, mp->m_rsumlevels,
> + mp->m_sb.sb_rbmblocks);
> descr = xchk_xfile_descr(sc, "realtime summary file");
> - error = xfile_create(descr, mp->m_rsumsize, &sc->xfile);
> + error = xfile_create(descr, wordcnt << XFS_WORDLOG, &sc->xfile);
> kfree(descr);
But this confuses me. What problem does it solve over just using
m_rsumsize?
