[PATCH 41/56] xfs: create routine to allocate and initialize a realtime refcount btree inode

["Darrick J. Wong" <djwong@xxxxxxxxxx>]

From: Darrick J. Wong <djwong@xxxxxxxxxx>

Source kernel commit: 4ee3113aaf3f6a3c24fcf952d8489363f56ab375

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

Signed-off-by: "Darrick J. Wong" <djwong@xxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
---
 libxfs/xfs_rtgroup.c          |    2 ++
 libxfs/xfs_rtrefcount_btree.c |   28 ++++++++++++++++++++++++++++
 libxfs/xfs_rtrefcount_btree.h |    3 +++
 3 files changed, 33 insertions(+)


diff --git a/libxfs/xfs_rtgroup.c b/libxfs/xfs_rtgroup.c
index e1f853dd2c5b3e..74701264265ce2 100644
--- a/libxfs/xfs_rtgroup.c
+++ b/libxfs/xfs_rtgroup.c
@@ -31,6 +31,7 @@
 #include "xfs_metafile.h"
 #include "xfs_metadir.h"
 #include "xfs_rtrmap_btree.h"
+#include "xfs_rtrefcount_btree.h"
 
 /* Find the first usable fsblock in this rtgroup. */
 static inline uint32_t
@@ -379,6 +380,7 @@ static const struct xfs_rtginode_ops xfs_rtginode_ops[XFS_RTGI_MAX] = {
 		.fmt_mask	= 1U << XFS_DINODE_FMT_META_BTREE,
 		/* same comment about growfs and rmap inodes applies here */
 		.enabled	= xfs_has_reflink,
+		.create		= xfs_rtrefcountbt_create,
 	},
 };
 
diff --git a/libxfs/xfs_rtrefcount_btree.c b/libxfs/xfs_rtrefcount_btree.c
index cf9f2ee5314dda..fa6c114d9cbc5a 100644
--- a/libxfs/xfs_rtrefcount_btree.c
+++ b/libxfs/xfs_rtrefcount_btree.c
@@ -719,3 +719,31 @@ xfs_iflush_rtrefcount(
 			ifp->if_broot_bytes, dfp,
 			XFS_DFORK_SIZE(dip, ip->i_mount, XFS_DATA_FORK));
 }
+
+/*
+ * Create a realtime refcount btree inode.
+ */
+int
+xfs_rtrefcountbt_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_rtrefcount_broot_space_calc(mp, 0, 0));
+	if (broot)
+		xfs_btree_init_block(mp, broot, &xfs_rtrefcountbt_ops, 0, 0,
+				ip->i_ino);
+	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE | XFS_ILOG_DBROOT);
+	return 0;
+}
diff --git a/libxfs/xfs_rtrefcount_btree.h b/libxfs/xfs_rtrefcount_btree.h
index e558a10c4744ad..a99b7a8aec8659 100644
--- a/libxfs/xfs_rtrefcount_btree.h
+++ b/libxfs/xfs_rtrefcount_btree.h
@@ -183,4 +183,7 @@ void xfs_rtrefcountbt_to_disk(struct xfs_mount *mp,
 		struct xfs_rtrefcount_root *dblock, int dblocklen);
 void xfs_iflush_rtrefcount(struct xfs_inode *ip, struct xfs_dinode *dip);
 
+int xfs_rtrefcountbt_create(struct xfs_rtgroup *rtg, struct xfs_inode *ip,
+		struct xfs_trans *tp, bool init);
+
 #endif	/* __XFS_RTREFCOUNT_BTREE_H__ */