xfs: create routine to allocate and initialize a realtime rmap btree inode

Create a library routine to allocate and initialize an empty realtime
rmapbt inode.  We'll use this for mkfs and repair.

Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

1 files changed, 54 insertions, 0 deletions

diff --git a/fs/xfs/libxfs/xfs_rtrmap_btree.c b/fs/xfs/libxfs/xfs_rtrmap_btree.c
index af0df0c7e61e1..4de7720d2f4e9 100644
--- a/fs/xfs/libxfs/xfs_rtrmap_btree.c
+++ b/fs/xfs/libxfs/xfs_rtrmap_btree.c
@@ -832,3 +832,57 @@ xfs_iflush_rtrmap(
 	xfs_rtrmapbt_to_disk(ip->i_mount, ifp->if_broot, ifp->if_broot_bytes,
 			dfp, XFS_DFORK_SIZE(dip, ip->i_mount, XFS_DATA_FORK));
 }
+
+/*
+ * Create a realtime rmap btree inode.
+ */
+int
+xfs_rtrmapbt_create(
+	struct xfs_rtgroup	*rtg,
+	struct xfs_inode	*ip,
+	struct xfs_trans	*tp,
+	bool			init)
+{
+	struct xfs_ifork	*ifp = xfs_ifork_ptr(ip, XFS_DATA_FORK);
+	struct xfs_mount	*mp = ip->i_mount;
+	struct xfs_btree_block	*broot;
+
+	ifp->if_format = XFS_DINODE_FMT_META_BTREE;
+	ASSERT(ifp->if_broot_bytes == 0);
+	ASSERT(ifp->if_bytes == 0);
+
+	/* Initialize the empty incore btree root. */
+	broot = xfs_broot_realloc(ifp, xfs_rtrmap_broot_space_calc(mp, 0, 0));
+	if (broot)
+		xfs_btree_init_block(mp, broot, &xfs_rtrmapbt_ops, 0, 0,
+				ip->i_ino);
+	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE | XFS_ILOG_DBROOT);
+
+	return 0;
+}
+
+/*
+ * Initialize an rmap for a realtime superblock using the potentially updated
+ * rt geometry in the provided @mp.
+ */
+int
+xfs_rtrmapbt_init_rtsb(
+	struct xfs_mount	*mp,
+	struct xfs_rtgroup	*rtg,
+	struct xfs_trans	*tp)
+{
+	struct xfs_rmap_irec	rmap = {
+		.rm_blockcount	= mp->m_sb.sb_rextsize,
+		.rm_owner	= XFS_RMAP_OWN_FS,
+	};
+	struct xfs_btree_cur	*cur;
+	int			error;
+
+	ASSERT(xfs_has_rtsb(mp));
+	ASSERT(rtg_rgno(rtg) == 0);
+
+	cur = xfs_rtrmapbt_init_cursor(tp, rtg);
+	error = xfs_rmap_map_raw(cur, &rmap);
+	xfs_btree_del_cursor(cur, error);
+	return error;
+}