Re: [PATCH 13/43] xfs: add a xfs_rtrmap_highest_rgbno helper

Darrick J. Wong
2025-02-06T20:55:28Z

On Thu, Feb 06, 2025 at 07:44:29AM +0100, Christoph Hellwig wrote:
> Add a helper to find the last offset mapped in the rtrmap. This will be
> used by the zoned code to find out where to start writing again on
> conventional devices without hardware zone support.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Looks ok,
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>

--D

> ---
> fs/xfs/libxfs/xfs_rtrmap_btree.c | 19 +++++++++++++++++++
> fs/xfs/libxfs/xfs_rtrmap_btree.h | 2 ++
> 2 files changed, 21 insertions(+)
>
> diff --git a/fs/xfs/libxfs/xfs_rtrmap_btree.c b/fs/xfs/libxfs/xfs_rtrmap_btree.c
> index e4ec36943cb7..9bdc2cbfc113 100644
> --- a/fs/xfs/libxfs/xfs_rtrmap_btree.c
> +++ b/fs/xfs/libxfs/xfs_rtrmap_btree.c
> @@ -1033,3 +1033,22 @@ xfs_rtrmapbt_init_rtsb(
> xfs_btree_del_cursor(cur, error);
> return error;
> }
> +
> +/*
> + * Return the highest rgbno currently tracked by the rmap for this rtg.
> + */
> +xfs_rgblock_t
> +xfs_rtrmap_highest_rgbno(
> + struct xfs_rtgroup *rtg)
> +{
> + struct xfs_btree_block *block = rtg_rmap(rtg)->i_df.if_broot;
> + union xfs_btree_key key = {};
> + struct xfs_btree_cur *cur;
> +
> + if (block->bb_numrecs == 0)
> + return NULLRGBLOCK;
> + cur = xfs_rtrmapbt_init_cursor(NULL, rtg);
> + xfs_btree_get_keys(cur, block, &key);
> + xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
> + return be32_to_cpu(key.__rmap_bigkey[1].rm_startblock);
> +}
> diff --git a/fs/xfs/libxfs/xfs_rtrmap_btree.h b/fs/xfs/libxfs/xfs_rtrmap_btree.h
> index 9d0915089891..e328fd62a149 100644
> --- a/fs/xfs/libxfs/xfs_rtrmap_btree.h
> +++ b/fs/xfs/libxfs/xfs_rtrmap_btree.h
> @@ -207,4 +207,6 @@ struct xfs_btree_cur *xfs_rtrmapbt_mem_cursor(struct xfs_rtgroup *rtg,
> int xfs_rtrmapbt_mem_init(struct xfs_mount *mp, struct xfbtree *xfbtree,
> struct xfs_buftarg *btp, xfs_rgnumber_t rgno);
>
> +xfs_rgblock_t xfs_rtrmap_highest_rgbno(struct xfs_rtgroup *rtg);
> +
> #endif /* __XFS_RTRMAP_BTREE_H__ */
> --
> 2.45.2
>
>