[PATCH] xfs: remove the unused m_chsize field

[PATCH] xfs: remove the unused m_chsize field

[Christoph Hellwig]

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/xfs/xfs_mount.h | 1 -
 1 file changed, 1 deletion(-)

diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
index 2dceb446e651..43145a4ab690 100644
--- a/fs/xfs/xfs_mount.h
+++ b/fs/xfs/xfs_mount.h
@@ -155,7 +155,6 @@ typedef struct xfs_mount {
 	int			m_swidth;	/* stripe width */
 	uint8_t			m_sectbb_log;	/* sectlog - BBSHIFT */
 	const struct xfs_nameops *m_dirnameops;	/* vector of dir name ops */
-	uint			m_chsize;	/* size of next field */
 	atomic_t		m_active_trans;	/* number trans frozen */
 	struct xfs_mru_cache	*m_filestream;  /* per-mount filestream data */
 	struct delayed_work	m_reclaim_work;	/* background inode reclaim */
-- 
2.20.1

Re: [PATCH] xfs: remove the unused m_chsize field

[Darrick J. Wong]

On Mon, Nov 11, 2019 at 07:09:57PM +0100, Christoph Hellwig wrote:
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Heh, what was that even used for?

Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>

--D

> ---
>  fs/xfs/xfs_mount.h | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
> index 2dceb446e651..43145a4ab690 100644
> --- a/fs/xfs/xfs_mount.h
> +++ b/fs/xfs/xfs_mount.h
> @@ -155,7 +155,6 @@ typedef struct xfs_mount {
>  	int			m_swidth;	/* stripe width */
>  	uint8_t			m_sectbb_log;	/* sectlog - BBSHIFT */
>  	const struct xfs_nameops *m_dirnameops;	/* vector of dir name ops */
> -	uint			m_chsize;	/* size of next field */
>  	atomic_t		m_active_trans;	/* number trans frozen */
>  	struct xfs_mru_cache	*m_filestream;  /* per-mount filestream data */
>  	struct delayed_work	m_reclaim_work;	/* background inode reclaim */
> -- 
> 2.20.1
> 

Re: [PATCH] xfs: remove the unused m_chsize field

[Eric Sandeen]

On 11/11/19 7:38 PM, Darrick J. Wong wrote:
> On Mon, Nov 11, 2019 at 07:09:57PM +0100, Christoph Hellwig wrote:
>> Signed-off-by: Christoph Hellwig <hch@lst.de>
> 
> Heh, what was that even used for?
> 
> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>

Looks like it was there in the original CVS import,
and got removed in 

commit da353b0d64e070ae7c5342a0d56ec20ae9ef5cfb
Author: David Chinner <dgc@sgi.com>
Date:   Tue Aug 28 14:00:13 2007 +1000

    [XFS] Radix tree based inode caching

Re: [PATCH] xfs: remove the unused m_chsize field

[Dave Chinner]

On Mon, Nov 11, 2019 at 05:38:10PM -0800, Darrick J. Wong wrote:
> On Mon, Nov 11, 2019 at 07:09:57PM +0100, Christoph Hellwig wrote:
> > Signed-off-by: Christoph Hellwig <hch@lst.de>
> 
> Heh, what was that even used for?

> > -	uint			m_chsize;	/* size of next field */

Inode cluster hash size.

We used to keep a linked list of all the inodes in a cluster in a
separate structure, so that we could easily iterate them when needed
(writeback/cluster freeing). They were kept in a separate hash table
so that they could be used as a quick reference inode cluster buffer
cache as well (IIRC it was to speed up things like xfs_imap_to_bp())
without having the overhead of a full buffer cache lookup...

The need for all this went away with the radix tree indexing and
gang lookups - I guess I missed removing this last fragment.

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com