[PATCH 16/32] xfs: add a xfs_rtblock_payload helper

[Christoph Hellwig <hch@lst.de>]

Source kernel commit: c63d609c1ed6dd49664e4f822a70abaf2572b35b

Add a helper to calculate the rtblock payload start with or without the
self-describing metadata header.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 libxfs/xfs_rtbitmap.c |  9 ++-------
 libxfs/xfs_rtbitmap.h | 27 ++++++++++++---------------
 2 files changed, 14 insertions(+), 22 deletions(-)

diff --git a/libxfs/xfs_rtbitmap.c b/libxfs/xfs_rtbitmap.c
index 245cdd9c22ca..39a6b45d9526 100644
--- a/libxfs/xfs_rtbitmap.c
+++ b/libxfs/xfs_rtbitmap.c
@@ -1408,7 +1408,6 @@ xfs_rtfile_initialize_block(
 	struct xfs_inode	*ip = rtg->rtg_inodes[type];
 	struct xfs_trans	*tp;
 	struct xfs_buf		*bp;
-	void			*bufdata;
 	const size_t		copylen = mp->m_blockwsize << XFS_WORDLOG;
 	int			error;
 
@@ -1424,16 +1423,12 @@ xfs_rtfile_initialize_block(
 		xfs_trans_cancel(tp);
 		return error;
 	}
-	bufdata = bp->b_addr;
 
 	xfs_rtfile_initialize_buf(rtg, type, bp, tp);
-
-	if (xfs_has_rtgroups(mp))
-		bufdata += sizeof(struct xfs_rtbuf_blkinfo);
 	if (data)
-		memcpy(bufdata, data, copylen);
+		memcpy(xfs_rtblock_payload(bp), data, copylen);
 	else
-		memset(bufdata, 0, copylen);
+		memset(xfs_rtblock_payload(bp), 0, copylen);
 	xfs_trans_log_buf(tp, bp, 0, mp->m_sb.sb_blocksize - 1);
 	return xfs_trans_commit(tp);
 }
diff --git a/libxfs/xfs_rtbitmap.h b/libxfs/xfs_rtbitmap.h
index 4a87e1fd3e99..750d74fbf4ed 100644
--- a/libxfs/xfs_rtbitmap.h
+++ b/libxfs/xfs_rtbitmap.h
@@ -20,6 +20,16 @@ struct xfs_rtalloc_args {
 	xfs_fileoff_t		sumoff;	/* summary block number */
 };
 
+/* Return the payload of the buffer after the optional header. */
+static inline void *
+xfs_rtblock_payload(
+	struct xfs_buf		*bp)
+{
+	if (!xfs_has_rtgroups(bp->b_mount))
+		return bp->b_addr;
+	return bp->b_addr + sizeof(struct xfs_rtbuf_blkinfo);
+}
+
 static inline xfs_rtblock_t
 xfs_rtx_to_rtb(
 	struct xfs_rtgroup	*rtg,
@@ -221,14 +231,7 @@ xfs_rbmblock_wordptr(
 	struct xfs_rtalloc_args	*args,
 	unsigned int		index)
 {
-	struct xfs_mount	*mp = args->mp;
-	union xfs_rtword_raw	*words;
-	struct xfs_rtbuf_blkinfo *hdr = args->rbmbp->b_addr;
-
-	if (xfs_has_rtgroups(mp))
-		words = (union xfs_rtword_raw *)(hdr + 1);
-	else
-		words = args->rbmbp->b_addr;
+	union xfs_rtword_raw	*words = xfs_rtblock_payload(args->rbmbp);
 
 	return words + index;
 }
@@ -312,13 +315,7 @@ xfs_rsumblock_infoptr(
 	struct xfs_rtalloc_args	*args,
 	unsigned int		index)
 {
-	union xfs_suminfo_raw	*info;
-	struct xfs_rtbuf_blkinfo *hdr = args->sumbp->b_addr;
-
-	if (xfs_has_rtgroups(args->mp))
-		info = (union xfs_suminfo_raw *)(hdr + 1);
-	else
-		info = args->sumbp->b_addr;
+	union xfs_suminfo_raw	*info = xfs_rtblock_payload(args->sumbp);
 
 	return info + index;
 }
-- 
2.53.0