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>

1 files changed, 43 insertions, 0 deletions

diff --git a/fs/xfs/libxfs/xfs_rtrmap_btree.c b/fs/xfs/libxfs/xfs_rtrmap_btree.c
index 80f6d3b34b96..10a487fd81be 100644
--- a/fs/xfs/libxfs/xfs_rtrmap_btree.c
+++ b/fs/xfs/libxfs/xfs_rtrmap_btree.c
@@ -27,6 +27,7 @@
 #include "xfs_extent_busy.h"
 #include "xfs_rtgroup.h"
 #include "xfs_bmap.h"
+#include "xfs_imeta.h"
 
 static struct kmem_cache	*xfs_rtrmapbt_cur_cache;
 
@@ -869,3 +870,45 @@ 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.
+ *
+ * Regardless of the return value, the caller must clean up @ic.  If a new
+ * inode is returned through *ipp, the caller must finish setting up the incore
+ * inode and release it.
+ */
+int
+xfs_rtrmapbt_create(
+	struct xfs_trans	**tpp,
+	struct xfs_imeta_path	*path,
+	struct xfs_imeta_update	*upd,
+	struct xfs_inode	**ipp)
+{
+	struct xfs_mount	*mp = (*tpp)->t_mountp;
+	struct xfs_ifork	*ifp;
+	struct xfs_inode	*ip;
+	int			error;
+
+	*ipp = NULL;
+
+	error = xfs_imeta_create(tpp, path, S_IFREG, 0, &ip, upd);
+	if (error)
+		return error;
+
+	ifp = &ip->i_df;
+	ifp->if_format = XFS_DINODE_FMT_RMAP;
+	ASSERT(ifp->if_broot_bytes == 0);
+	ASSERT(ifp->if_bytes == 0);
+
+	/* Initialize the empty incore btree root. */
+	xfs_iroot_alloc(ip, XFS_DATA_FORK,
+			xfs_rtrmap_broot_space_calc(mp, 0, 0));
+	xfs_btree_init_block_int(mp, ifp->if_broot,
+			XFS_BUF_DADDR_NULL, XFS_BTNUM_RTRMAP, 0, 0, ip->i_ino,
+			XFS_BTREE_LONG_PTRS | XFS_BTREE_CRC_BLOCKS);
+	xfs_trans_log_inode(*tpp, ip, XFS_ILOG_CORE | XFS_ILOG_DBROOT);
+
+	*ipp = ip;
+	return 0;
+}