From: Nirjhar Roy (IBM) <nirjhar.roy.lists@gmail.com>
Date: Mon, 2 Mar 2026 01:39:59 +0000 (-0800)
Subject: xfs: Refactoring the nagcount and delta calculation
X-Git-Tag: v7.0.0~67
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=1dff948c0bbdd6141bcf7ca176a9c3c870472f0f;p=xfsprogs-dev.git

xfs: Refactoring the nagcount and delta calculation

Source kernel commit: a49b7ff63f98ba1c4503869c568c99ecffa478f2

Introduce xfs_growfs_compute_delta() to calculate the nagcount
and delta blocks and refactor the code from xfs_growfs_data_private().
No functional changes.

Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nirjhar Roy (IBM) <nirjhar.roy.lists@gmail.com>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
---

diff --git a/libxfs/xfs_ag.c b/libxfs/xfs_ag.c
index 5742d59a..fd5f902b 100644
--- a/libxfs/xfs_ag.c
+++ b/libxfs/xfs_ag.c
@@ -870,6 +870,34 @@ resv_err:
 	return err2;
 }
 
+void
+xfs_growfs_compute_deltas(
+	struct xfs_mount	*mp,
+	xfs_rfsblock_t		nb,
+	int64_t			*deltap,
+	xfs_agnumber_t		*nagcountp)
+{
+	xfs_rfsblock_t	nb_div, nb_mod;
+	int64_t		delta;
+	xfs_agnumber_t	nagcount;
+
+	nb_div = nb;
+	nb_mod = do_div(nb_div, mp->m_sb.sb_agblocks);
+	if (nb_mod && nb_mod >= XFS_MIN_AG_BLOCKS)
+		nb_div++;
+	else if (nb_mod)
+		nb = nb_div * mp->m_sb.sb_agblocks;
+
+	if (nb_div > XFS_MAX_AGNUMBER + 1) {
+		nb_div = XFS_MAX_AGNUMBER + 1;
+		nb = nb_div * mp->m_sb.sb_agblocks;
+	}
+	nagcount = nb_div;
+	delta = nb - mp->m_sb.sb_dblocks;
+	*deltap = delta;
+	*nagcountp = nagcount;
+}
+
 /*
  * Extent the AG indicated by the @id by the length passed in
  */
diff --git a/libxfs/xfs_ag.h b/libxfs/xfs_ag.h
index 1f24cfa2..3cd47907 100644
--- a/libxfs/xfs_ag.h
+++ b/libxfs/xfs_ag.h
@@ -331,6 +331,9 @@ struct aghdr_init_data {
 int xfs_ag_init_headers(struct xfs_mount *mp, struct aghdr_init_data *id);
 int xfs_ag_shrink_space(struct xfs_perag *pag, struct xfs_trans **tpp,
 			xfs_extlen_t delta);
+void
+xfs_growfs_compute_deltas(struct xfs_mount *mp, xfs_rfsblock_t nb,
+			int64_t *deltap, xfs_agnumber_t *nagcountp);
 int xfs_ag_extend_space(struct xfs_perag *pag, struct xfs_trans *tp,
 			xfs_extlen_t len);
 int xfs_ag_get_geometry(struct xfs_perag *pag, struct xfs_ag_geometry *ageo);