Re: [PATCH 19/21] xfs: report RT data checksum information via XFS_FSOP_GEOM

["Darrick J. Wong" <djwong@kernel.org>]

On Thu, Sep 24, 2026 at 11:59:51AM +0200, Christoph Hellwig wrote:
> Report the RT data checksum flag and the checksum algorithm to userspace.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Looks good to me
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>

--D

> ---
>  fs/xfs/libxfs/xfs_fs.h | 6 +++++-
>  fs/xfs/libxfs/xfs_sb.c | 5 +++++
>  2 files changed, 10 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/xfs/libxfs/xfs_fs.h b/fs/xfs/libxfs/xfs_fs.h
> index 185f09f327c0..afe83ff23ef3 100644
> --- a/fs/xfs/libxfs/xfs_fs.h
> +++ b/fs/xfs/libxfs/xfs_fs.h
> @@ -191,7 +191,10 @@ struct xfs_fsop_geom {
>  	__u32		rgcount;	/* number of realtime groups	*/
>  	__u64		rtstart;	/* start of internal rt section */
>  	__u64		rtreserved;	/* RT (zoned) reserved blocks	*/
> -	__u64		reserved[14];	/* reserved space		*/
> +	__u8		rtcsum_type;	/* RT data checksum type	*/
> +	__u8		rtcsum_blklog;	/* log2 of rtcsum bsize		*/
> +	__u8		reserved_pad[6];/* reserved space		*/
> +	__u64		reserved[13];	/* reserved space		*/
>  };
>  
>  #define XFS_FSOP_GEOM_SICK_COUNTERS	(1 << 0)  /* summary counters */
> @@ -250,6 +253,7 @@ typedef struct xfs_fsop_resblks {
>  #define XFS_FSOP_GEOM_FLAGS_PARENT	(1 << 25) /* linux parent pointers */
>  #define XFS_FSOP_GEOM_FLAGS_METADIR	(1 << 26) /* metadata directories */
>  #define XFS_FSOP_GEOM_FLAGS_ZONED	(1 << 27) /* zoned rt device */
> +#define XFS_FSOP_GEOM_FLAGS_DATA_CSUM	(1 << 28) /* data checksums */
>  
>  /*
>   * Minimum and maximum sizes need for growth checks.
> diff --git a/fs/xfs/libxfs/xfs_sb.c b/fs/xfs/libxfs/xfs_sb.c
> index 3a470aec6c0c..506caf3e5201 100644
> --- a/fs/xfs/libxfs/xfs_sb.c
> +++ b/fs/xfs/libxfs/xfs_sb.c
> @@ -1660,6 +1660,11 @@ xfs_fs_geometry(
>  		geo->flags |= XFS_FSOP_GEOM_FLAGS_METADIR;
>  	if (xfs_has_zoned(mp))
>  		geo->flags |= XFS_FSOP_GEOM_FLAGS_ZONED;
> +	if (xfs_has_rtcsum(mp)) {
> +		geo->flags |= XFS_FSOP_GEOM_FLAGS_DATA_CSUM;
> +		geo->rtcsum_type = mp->m_sb.sb_rtcsum_type;
> +		geo->rtcsum_blklog = mp->m_sb.sb_rtcsum_blklog;
> +	}
>  	geo->rtsectsize = sbp->sb_blocksize;
>  	geo->dirblocksize = xfs_dir2_dirblock_bytes(sbp);
>  
> -- 
> 2.53.0
> 
>