xfs: refactor free space btree record initialization

Refactor the code that populates the free space btrees of a new AG so
that we can avoid code duplication once things start getting
complicated.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Allison Collins <allison.henderson@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

fs/xfs/libxfs/xfs_ag.c

@@ -56,37 +56,42 @@ xfs_btroot_init(
 	xfs_btree_init_block(mp, bp, id->type, 0, 0, id->agno);
 }
 
-/*
- * Alloc btree root block init functions
- */
+/* Finish initializing a free space btree. */
 static void
-xfs_bnoroot_init(
+xfs_freesp_init_recs(
 	struct xfs_mount	*mp,
 	struct xfs_buf		*bp,
 	struct aghdr_init_data	*id)
 {
 	struct xfs_alloc_rec	*arec;
 
-	xfs_btree_init_block(mp, bp, XFS_BTNUM_BNO, 0, 1, id->agno);
 	arec = XFS_ALLOC_REC_ADDR(mp, XFS_BUF_TO_BLOCK(bp), 1);
 	arec->ar_startblock = cpu_to_be32(mp->m_ag_prealloc_blocks);
 	arec->ar_blockcount = cpu_to_be32(id->agsize -
 					  be32_to_cpu(arec->ar_startblock));
 }
 
+/*
+ * Alloc btree root block init functions
+ */
 static void
-xfs_cntroot_init(
+xfs_bnoroot_init(
 	struct xfs_mount	*mp,
 	struct xfs_buf		*bp,
 	struct aghdr_init_data	*id)
 {
-	struct xfs_alloc_rec	*arec;
+	xfs_btree_init_block(mp, bp, XFS_BTNUM_BNO, 0, 1, id->agno);
+	xfs_freesp_init_recs(mp, bp, id);
+}
 
+static void
+xfs_cntroot_init(
+	struct xfs_mount	*mp,
+	struct xfs_buf		*bp,
+	struct aghdr_init_data	*id)
+{
 	xfs_btree_init_block(mp, bp, XFS_BTNUM_CNT, 0, 1, id->agno);
-	arec = XFS_ALLOC_REC_ADDR(mp, XFS_BUF_TO_BLOCK(bp), 1);
-	arec->ar_startblock = cpu_to_be32(mp->m_ag_prealloc_blocks);
-	arec->ar_blockcount = cpu_to_be32(id->agsize -
-					  be32_to_cpu(arec->ar_startblock));
+	xfs_freesp_init_recs(mp, bp, id);
 }
 
 /*