Re: [PATCH 4/5] xfs: precalculate inodes and blocks per inode cluster

[Brian Foster <bfoster@redhat.com>]

On Thu, Nov 08, 2018 at 03:20:33PM -0800, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@oracle.com>
> 
> Store the number of inodes and blocks per inode cluster in the mount
> data so that we don't have to keep recalculating them.
> 
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> ---
>  fs/xfs/libxfs/xfs_ialloc.c |   23 ++++++++++-------------
>  fs/xfs/scrub/ialloc.c      |   14 ++++++--------
>  fs/xfs/xfs_inode.c         |   14 +++++---------
>  fs/xfs/xfs_itable.c        |   14 ++++++--------
>  fs/xfs/xfs_log_recover.c   |    8 +++-----
>  fs/xfs/xfs_mount.c         |    2 ++
>  fs/xfs/xfs_mount.h         |    2 ++
>  7 files changed, 34 insertions(+), 43 deletions(-)
> 
> 
...
> diff --git a/fs/xfs/scrub/ialloc.c b/fs/xfs/scrub/ialloc.c
> index 426eb1a5503c..332ac7b61789 100644
> --- a/fs/xfs/scrub/ialloc.c
> +++ b/fs/xfs/scrub/ialloc.c
> @@ -193,18 +193,16 @@ xchk_iallocbt_check_freemask(
>  	xfs_agino_t			chunkino;
>  	xfs_agino_t			clusterino;
>  	xfs_agblock_t			agbno;
> -	int				blks_per_cluster;
>  	uint16_t			holemask;
>  	uint16_t			ir_holemask;
>  	int				error = 0;
>  
>  	/* Make sure the freemask matches the inode records. */
> -	blks_per_cluster = xfs_icluster_size_fsb(mp);
> -	nr_inodes = XFS_FSB_TO_INO(mp, blks_per_cluster);
> +	nr_inodes = mp->m_inodes_per_cluster;

Why keep nr_inodes? Doesn't look like it changes anywhere..

>  
>  	for (agino = irec->ir_startino;
>  	     agino < irec->ir_startino + XFS_INODES_PER_CHUNK;
> -	     agino += blks_per_cluster * mp->m_sb.sb_inopblock) {
> +	     agino += mp->m_blocks_per_cluster * mp->m_sb.sb_inopblock) {

... and this looks like m_inodes_per_cluster.

>  		fsino = XFS_AGINO_TO_INO(mp, bs->cur->bc_private.a.agno, agino);
>  		chunkino = agino - irec->ir_startino;
>  		agbno = XFS_AGINO_TO_AGBNO(mp, agino);
> @@ -225,18 +223,18 @@ xchk_iallocbt_check_freemask(
>  		/* If any part of this is a hole, skip it. */
>  		if (ir_holemask) {
>  			xchk_xref_is_not_owned_by(bs->sc, agbno,
> -					blks_per_cluster,
> +					mp->m_blocks_per_cluster,
>  					&XFS_RMAP_OINFO_INODES);
>  			continue;
>  		}
>  
> -		xchk_xref_is_owned_by(bs->sc, agbno, blks_per_cluster,
> +		xchk_xref_is_owned_by(bs->sc, agbno, mp->m_blocks_per_cluster,
>  				&XFS_RMAP_OINFO_INODES);
>  
>  		/* Grab the inode cluster buffer. */
>  		imap.im_blkno = XFS_AGB_TO_DADDR(mp, bs->cur->bc_private.a.agno,
>  				agbno);
> -		imap.im_len = XFS_FSB_TO_BB(mp, blks_per_cluster);
> +		imap.im_len = XFS_FSB_TO_BB(mp, mp->m_blocks_per_cluster);
>  		imap.im_boffset = 0;
>  
>  		error = xfs_imap_to_bp(mp, bs->cur->bc_tp, &imap,
> @@ -303,7 +301,7 @@ xchk_iallocbt_rec(
>  	/* Make sure this record is aligned to cluster and inoalignmnt size. */
>  	agbno = XFS_AGINO_TO_AGBNO(mp, irec.ir_startino);
>  	if ((agbno & (xfs_ialloc_cluster_alignment(mp) - 1)) ||
> -	    (agbno & (xfs_icluster_size_fsb(mp) - 1)))
> +	    (agbno & (mp->m_blocks_per_cluster - 1)))
>  		xchk_btree_set_corrupt(bs->sc, bs->cur, 0);
>  
>  	*inode_blocks += XFS_B_TO_FSB(mp,
...
> diff --git a/fs/xfs/xfs_itable.c b/fs/xfs/xfs_itable.c
> index 18d8d3b812a7..00828b57e1f8 100644
> --- a/fs/xfs/xfs_itable.c
> +++ b/fs/xfs/xfs_itable.c
> @@ -167,20 +167,18 @@ xfs_bulkstat_ichunk_ra(
>  {
>  	xfs_agblock_t			agbno;
>  	struct blk_plug			plug;
> -	int				blks_per_cluster;
> -	int				inodes_per_cluster;
>  	int				i;	/* inode chunk index */
>  
>  	agbno = XFS_AGINO_TO_AGBNO(mp, irec->ir_startino);
> -	blks_per_cluster = xfs_icluster_size_fsb(mp);
> -	inodes_per_cluster = XFS_FSB_TO_INO(mp, blks_per_cluster);
>  
>  	blk_start_plug(&plug);
>  	for (i = 0; i < XFS_INODES_PER_CHUNK;
> -	     i += inodes_per_cluster, agbno += blks_per_cluster) {
> -		if (xfs_inobt_maskn(i, inodes_per_cluster) & ~irec->ir_free) {
> -			xfs_btree_reada_bufs(mp, agno, agbno, blks_per_cluster,
> -					     &xfs_inode_buf_ops);
> +	     i += mp->m_inodes_per_cluster, agbno += mp->m_blocks_per_cluster) {
> +		if (xfs_inobt_maskn(i, mp->m_inodes_per_cluster) &
> +				~irec->ir_free) {

Just another nit, this should probably be aligned like so:

		if (xfs_inobt_maskn(i, mp->m_inodes_per_cluster) &
		    ~irec->ir_free) {
			...
		}

... right?

Brian

> +			xfs_btree_reada_bufs(mp, agno, agbno,
> +					mp->m_blocks_per_cluster,
> +					&xfs_inode_buf_ops);
>  		}
>  	}
>  	blk_finish_plug(&plug);
> diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c
> index 1fc9e9042e0e..9fe88d125f0a 100644
> --- a/fs/xfs/xfs_log_recover.c
> +++ b/fs/xfs/xfs_log_recover.c
> @@ -3850,7 +3850,6 @@ xlog_recover_do_icreate_pass2(
>  	unsigned int		count;
>  	unsigned int		isize;
>  	xfs_agblock_t		length;
> -	int			blks_per_cluster;
>  	int			bb_per_cluster;
>  	int			cancel_count;
>  	int			nbufs;
> @@ -3918,14 +3917,13 @@ xlog_recover_do_icreate_pass2(
>  	 * buffers for cancellation so we don't overwrite anything written after
>  	 * a cancellation.
>  	 */
> -	blks_per_cluster = xfs_icluster_size_fsb(mp);
> -	bb_per_cluster = XFS_FSB_TO_BB(mp, blks_per_cluster);
> -	nbufs = length / blks_per_cluster;
> +	bb_per_cluster = XFS_FSB_TO_BB(mp, mp->m_blocks_per_cluster);
> +	nbufs = length / mp->m_blocks_per_cluster;
>  	for (i = 0, cancel_count = 0; i < nbufs; i++) {
>  		xfs_daddr_t	daddr;
>  
>  		daddr = XFS_AGB_TO_DADDR(mp, agno,
> -					 agbno + i * blks_per_cluster);
> +					 agbno + i * mp->m_blocks_per_cluster);
>  		if (xlog_check_buffer_cancelled(log, daddr, bb_per_cluster, 0))
>  			cancel_count++;
>  	}
> diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
> index 02d15098dbee..56d374675fd5 100644
> --- a/fs/xfs/xfs_mount.c
> +++ b/fs/xfs/xfs_mount.c
> @@ -798,6 +798,8 @@ xfs_mountfs(
>  		if (mp->m_sb.sb_inoalignmt >= XFS_B_TO_FSBT(mp, new_size))
>  			mp->m_inode_cluster_size = new_size;
>  	}
> +	mp->m_blocks_per_cluster = xfs_icluster_size_fsb(mp);
> +	mp->m_inodes_per_cluster = XFS_FSB_TO_INO(mp, mp->m_blocks_per_cluster);
>  
>  	/*
>  	 * If enabled, sparse inode chunk alignment is expected to match the
> diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
> index 7964513c3128..58a037bfac22 100644
> --- a/fs/xfs/xfs_mount.h
> +++ b/fs/xfs/xfs_mount.h
> @@ -101,6 +101,8 @@ typedef struct xfs_mount {
>  	uint8_t			m_agno_log;	/* log #ag's */
>  	uint8_t			m_agino_log;	/* #bits for agino in inum */
>  	uint			m_inode_cluster_size;/* min inode buf size */
> +	unsigned int		m_inodes_per_cluster;
> +	unsigned int		m_blocks_per_cluster;
>  	uint			m_blockmask;	/* sb_blocksize-1 */
>  	uint			m_blockwsize;	/* sb_blocksize in words */
>  	uint			m_blockwmask;	/* blockwsize-1 */
>