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>

2 files changed, 53 insertions, 0 deletions

diff --git a/fs/xfs/libxfs/xfs_rtrmap_btree.c b/fs/xfs/libxfs/xfs_rtrmap_btree.c
index 3f47586a7711..6684ec59bc7a 100644
--- a/fs/xfs/libxfs/xfs_rtrmap_btree.c
+++ b/fs/xfs/libxfs/xfs_rtrmap_btree.c
@@ -25,6 +25,7 @@
 #include "xfs_error.h"
 #include "xfs_extent_busy.h"
 #include "xfs_bmap.h"
+#include "xfs_imeta.h"
 
 static struct kmem_cache	*xfs_rtrmapbt_cur_cache;
 
@@ -797,3 +798,50 @@ 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_end	*ic,
+	struct xfs_inode	**ipp)
+{
+	struct xfs_mount	*mp = (*tpp)->t_mountp;
+	struct xfs_ifork	*ifp;
+	struct xfs_inode	*ip;
+	xfs_ino_t		ino = NULLFSINO;
+	int			error;
+
+	*ipp = NULL;
+	error = xfs_imeta_lookup(mp, &XFS_IMETA_RTRMAPBT, &ino);
+	if (error)
+		return error;
+	if (ino != NULLFSINO)
+		return -EEXIST;
+
+	error = xfs_imeta_create(tpp, &XFS_IMETA_RTRMAPBT, S_IFREG, 0, ipp, ic);
+	if (error)
+		return error;
+
+	ip = *ipp;
+	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(ip->i_mount, 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);
+
+	return 0;
+}
diff --git a/fs/xfs/libxfs/xfs_rtrmap_btree.h b/fs/xfs/libxfs/xfs_rtrmap_btree.h
index 704ce98b938b..568fd376bed2 100644
--- a/fs/xfs/libxfs/xfs_rtrmap_btree.h
+++ b/fs/xfs/libxfs/xfs_rtrmap_btree.h
@@ -191,4 +191,9 @@ void xfs_rtrmapbt_to_disk(struct xfs_mount *mp, struct xfs_btree_block *rblock,
 		unsigned int dblocklen);
 void xfs_iflush_rtrmap(struct xfs_inode *ip, struct xfs_dinode *dip);
 
+struct xfs_imeta_end;
+
+int xfs_rtrmapbt_create(struct xfs_trans **tpp, struct xfs_imeta_end *ic,
+		struct xfs_inode **ipp);
+
 #endif	/* __XFS_RTRMAP_BTREE_H__ */