Re: [PATCH 31/43] xfs: support growfs on zoned file systems

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

On Wed, Dec 11, 2024 at 09:54:56AM +0100, Christoph Hellwig wrote:
> Replace the inner loop growing one RT bitmap block at a time with
> one just modifying the superblock counters for growing an entire
> zone (aka RTG).  The big restriction is just like at mkfs time only
> a RT extent size of a single FSB is allowed, and the file system
> capacity needs to be aligned to the zone size.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Got it, that really is nice to do growfs a group at a time.
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>

--D

> ---
>  fs/xfs/xfs_rtalloc.c | 121 ++++++++++++++++++++++++++++++++++++-------
>  1 file changed, 101 insertions(+), 20 deletions(-)
> 
> diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c
> index 47c94ac74259..e21baa494c33 100644
> --- a/fs/xfs/xfs_rtalloc.c
> +++ b/fs/xfs/xfs_rtalloc.c
> @@ -860,6 +860,84 @@ xfs_growfs_rt_init_rtsb(
>  	return error;
>  }
>  
> +static void
> +xfs_growfs_rt_sb_fields(
> +	struct xfs_trans	*tp,
> +	const struct xfs_mount	*nmp)
> +{
> +	struct xfs_mount	*mp = tp->t_mountp;
> +
> +	if (nmp->m_sb.sb_rextsize != mp->m_sb.sb_rextsize)
> +		xfs_trans_mod_sb(tp, XFS_TRANS_SB_REXTSIZE,
> +			nmp->m_sb.sb_rextsize - mp->m_sb.sb_rextsize);
> +	if (nmp->m_sb.sb_rbmblocks != mp->m_sb.sb_rbmblocks)
> +		xfs_trans_mod_sb(tp, XFS_TRANS_SB_RBMBLOCKS,
> +			nmp->m_sb.sb_rbmblocks - mp->m_sb.sb_rbmblocks);
> +	if (nmp->m_sb.sb_rblocks != mp->m_sb.sb_rblocks)
> +		xfs_trans_mod_sb(tp, XFS_TRANS_SB_RBLOCKS,
> +			nmp->m_sb.sb_rblocks - mp->m_sb.sb_rblocks);
> +	if (nmp->m_sb.sb_rextents != mp->m_sb.sb_rextents)
> +		xfs_trans_mod_sb(tp, XFS_TRANS_SB_REXTENTS,
> +			nmp->m_sb.sb_rextents - mp->m_sb.sb_rextents);
> +	if (nmp->m_sb.sb_rextslog != mp->m_sb.sb_rextslog)
> +		xfs_trans_mod_sb(tp, XFS_TRANS_SB_REXTSLOG,
> +			nmp->m_sb.sb_rextslog - mp->m_sb.sb_rextslog);
> +	if (nmp->m_sb.sb_rgcount != mp->m_sb.sb_rgcount)
> +		xfs_trans_mod_sb(tp, XFS_TRANS_SB_RGCOUNT,
> +			nmp->m_sb.sb_rgcount - mp->m_sb.sb_rgcount);
> +}
> +
> +static int
> +xfs_growfs_rt_zoned(
> +	struct xfs_rtgroup	*rtg,
> +	xfs_rfsblock_t		nrblocks)
> +{
> +	struct xfs_mount	*mp = rtg_mount(rtg);
> +	struct xfs_mount	*nmp;
> +	struct xfs_trans	*tp;
> +	xfs_rtbxlen_t		freed_rtx;
> +	int			error;
> +
> +	/*
> +	 * Calculate new sb and mount fields for this round.  Also ensure the
> +	 * rtg_extents value is uptodate as the rtbitmap code relies on it.
> +	 */
> +	nmp = xfs_growfs_rt_alloc_fake_mount(mp, nrblocks,
> +			mp->m_sb.sb_rextsize);
> +	if (!nmp)
> +		return -ENOMEM;
> +	freed_rtx = nmp->m_sb.sb_rextents - mp->m_sb.sb_rextents;
> +
> +	xfs_rtgroup_calc_geometry(nmp, rtg, rtg_rgno(rtg),
> +			nmp->m_sb.sb_rgcount, nmp->m_sb.sb_rextents);
> +
> +	error = xfs_trans_alloc(mp, &M_RES(nmp)->tr_growrtfree, 0, 0, 0, &tp);
> +	if (error)
> +		goto out_free;
> +
> +	xfs_rtgroup_lock(rtg, XFS_RTGLOCK_RMAP);
> +	xfs_rtgroup_trans_join(tp, rtg, XFS_RTGLOCK_RMAP);
> +
> +	xfs_growfs_rt_sb_fields(tp, nmp);
> +	xfs_trans_mod_sb(tp, XFS_TRANS_SB_FREXTENTS, freed_rtx);
> +
> +	error = xfs_trans_commit(tp);
> +	if (error)
> +		goto out_free;
> +
> +	/*
> +	 * Ensure the mount RT feature flag is now set, and compute new
> +	 * maxlevels for rt btrees.
> +	 */
> +	mp->m_features |= XFS_FEAT_REALTIME;
> +	xfs_rtrmapbt_compute_maxlevels(mp);
> +	xfs_rtrefcountbt_compute_maxlevels(mp);
> +	xfs_zoned_add_available(mp, freed_rtx);
> +out_free:
> +	kfree(nmp);
> +	return error;
> +}
> +
>  static int
>  xfs_growfs_rt_bmblock(
>  	struct xfs_rtgroup	*rtg,
> @@ -945,24 +1023,7 @@ xfs_growfs_rt_bmblock(
>  	/*
>  	 * Update superblock fields.
>  	 */
> -	if (nmp->m_sb.sb_rextsize != mp->m_sb.sb_rextsize)
> -		xfs_trans_mod_sb(args.tp, XFS_TRANS_SB_REXTSIZE,
> -			nmp->m_sb.sb_rextsize - mp->m_sb.sb_rextsize);
> -	if (nmp->m_sb.sb_rbmblocks != mp->m_sb.sb_rbmblocks)
> -		xfs_trans_mod_sb(args.tp, XFS_TRANS_SB_RBMBLOCKS,
> -			nmp->m_sb.sb_rbmblocks - mp->m_sb.sb_rbmblocks);
> -	if (nmp->m_sb.sb_rblocks != mp->m_sb.sb_rblocks)
> -		xfs_trans_mod_sb(args.tp, XFS_TRANS_SB_RBLOCKS,
> -			nmp->m_sb.sb_rblocks - mp->m_sb.sb_rblocks);
> -	if (nmp->m_sb.sb_rextents != mp->m_sb.sb_rextents)
> -		xfs_trans_mod_sb(args.tp, XFS_TRANS_SB_REXTENTS,
> -			nmp->m_sb.sb_rextents - mp->m_sb.sb_rextents);
> -	if (nmp->m_sb.sb_rextslog != mp->m_sb.sb_rextslog)
> -		xfs_trans_mod_sb(args.tp, XFS_TRANS_SB_REXTSLOG,
> -			nmp->m_sb.sb_rextslog - mp->m_sb.sb_rextslog);
> -	if (nmp->m_sb.sb_rgcount != mp->m_sb.sb_rgcount)
> -		xfs_trans_mod_sb(args.tp, XFS_TRANS_SB_RGCOUNT,
> -			nmp->m_sb.sb_rgcount - mp->m_sb.sb_rgcount);
> +	xfs_growfs_rt_sb_fields(args.tp, nmp);
>  
>  	/*
>  	 * Free the new extent.
> @@ -1129,6 +1190,11 @@ xfs_growfs_rtg(
>  			goto out_rele;
>  	}
>  
> +	if (xfs_has_zoned(mp)) {
> +		error = xfs_growfs_rt_zoned(rtg, nrblocks);
> +		goto out_rele;
> +	}
> +
>  	error = xfs_growfs_rt_alloc_blocks(rtg, nrblocks, rextsize, &bmblocks);
>  	if (error)
>  		goto out_rele;
> @@ -1148,8 +1214,7 @@ xfs_growfs_rtg(
>  
>  	if (old_rsum_cache)
>  		kvfree(old_rsum_cache);
> -	xfs_rtgroup_rele(rtg);
> -	return 0;
> +	goto out_rele;
>  
>  out_error:
>  	/*
> @@ -1197,6 +1262,22 @@ xfs_growfs_check_rtgeom(
>  
>  	if (min_logfsbs > mp->m_sb.sb_logblocks)
>  		return -EINVAL;
> +
> +	if (xfs_has_zoned(mp)) {
> +		uint32_t	gblocks = mp->m_groups[XG_TYPE_RTG].blocks;
> +		uint32_t	rem;
> +
> +		if (rextsize != 1)
> +			return -EINVAL;
> +		div_u64_rem(mp->m_sb.sb_rblocks, gblocks, &rem);
> +		if (rem) {
> +			xfs_warn(mp,
> +"new RT volume size (%lld) not aligned to RT group size (%d)",
> +				mp->m_sb.sb_rblocks, gblocks);
> +			return -EINVAL;
> +		}
> +	}
> +
>  	return 0;
>  }
>  
> -- 
> 2.45.2
> 
>