2 files changed, 31 insertions, 0 deletions

diff --git a/fs/xfs/libxfs/xfs_rtbitmap.h b/fs/xfs/libxfs/xfs_rtbitmap.h
index ecf5645dd670..3686a53e0aed 100644
--- a/fs/xfs/libxfs/xfs_rtbitmap.h
+++ b/fs/xfs/libxfs/xfs_rtbitmap.h
@@ -11,6 +11,9 @@ xfs_rtx_to_rtb(
 	struct xfs_mount	*mp,
 	xfs_rtxnum_t		rtx)
 {
+	if (mp->m_rtxblklog >= 0)
+		return rtx << mp->m_rtxblklog;
+
 	return rtx * mp->m_sb.sb_rextsize;
 }
 
@@ -19,6 +22,9 @@ xfs_rtxlen_to_extlen(
 	struct xfs_mount	*mp,
 	xfs_rtxlen_t		rtxlen)
 {
+	if (mp->m_rtxblklog >= 0)
+		return rtxlen << mp->m_rtxblklog;
+
 	return rtxlen * mp->m_sb.sb_rextsize;
 }
 
@@ -28,6 +34,9 @@ xfs_extlen_to_rtxmod(
 	struct xfs_mount	*mp,
 	xfs_extlen_t		len)
 {
+	if (mp->m_rtxblklog >= 0)
+		return len & mp->m_rtxblkmask;
+
 	return len % mp->m_sb.sb_rextsize;
 }
 
@@ -36,6 +45,9 @@ xfs_extlen_to_rtxlen(
 	struct xfs_mount	*mp,
 	xfs_extlen_t		len)
 {
+	if (mp->m_rtxblklog >= 0)
+		return len >> mp->m_rtxblklog;
+
 	return len / mp->m_sb.sb_rextsize;
 }
 
@@ -45,6 +57,9 @@ xfs_rtb_to_rtx(
 	struct xfs_mount	*mp,
 	xfs_rtblock_t		rtbno)
 {
+	if (likely(mp->m_rtxblklog >= 0))
+		return rtbno >> mp->m_rtxblklog;
+
 	return div_u64(rtbno, mp->m_sb.sb_rextsize);
 }
 
@@ -54,6 +69,9 @@ xfs_rtb_to_rtxoff(
 	struct xfs_mount	*mp,
 	xfs_rtblock_t		rtbno)
 {
+	if (likely(mp->m_rtxblklog >= 0))
+		return rtbno & mp->m_rtxblkmask;
+
 	return do_div(rtbno, mp->m_sb.sb_rextsize);
 }
 
@@ -67,6 +85,11 @@ xfs_rtb_to_rtxrem(
 	xfs_rtblock_t		rtbno,
 	xfs_extlen_t		*off)
 {
+	if (likely(mp->m_rtxblklog >= 0)) {
+		*off = rtbno & mp->m_rtxblkmask;
+		return rtbno >> mp->m_rtxblklog;
+	}
+
 	return div_u64_rem(rtbno, mp->m_sb.sb_rextsize, off);
 }
 
@@ -79,6 +102,12 @@ xfs_rtb_to_rtxup(
 	struct xfs_mount	*mp,
 	xfs_rtblock_t		rtbno)
 {
+	if (likely(mp->m_rtxblklog >= 0)) {
+		if (rtbno & mp->m_rtxblkmask)
+			return (rtbno >> mp->m_rtxblklog) + 1;
+		return rtbno >> mp->m_rtxblklog;
+	}
+
 	if (do_div(rtbno, mp->m_sb.sb_rextsize))
 		rtbno++;
 	return rtbno;
diff --git a/fs/xfs/libxfs/xfs_sb.c b/fs/xfs/libxfs/xfs_sb.c
index 6264daaab37b..1f74d0cd1618 100644
--- a/fs/xfs/libxfs/xfs_sb.c
+++ b/fs/xfs/libxfs/xfs_sb.c
@@ -975,6 +975,8 @@ xfs_sb_mount_common(
 	mp->m_blockmask = sbp->sb_blocksize - 1;
 	mp->m_blockwsize = sbp->sb_blocksize >> XFS_WORDLOG;
 	mp->m_blockwmask = mp->m_blockwsize - 1;
+	mp->m_rtxblklog = log2_if_power2(sbp->sb_rextsize);
+	mp->m_rtxblkmask = mask64_if_power2(sbp->sb_rextsize);
 
 	mp->m_alloc_mxr[0] = xfs_allocbt_maxrecs(mp, sbp->sb_blocksize, 1);
 	mp->m_alloc_mxr[1] = xfs_allocbt_maxrecs(mp, sbp->sb_blocksize, 0);