xfs: factor out xfs_attr3_leaf_init

Factor out wrapper xfs_attr3_leaf_init function, which exported for
external use.

Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Long Li <leo.lilong@huawei.com>
Signed-off-by: Carlos Maiolino <cem@kernel.org>

Author: Long Li

fs/xfs/libxfs/xfs_attr_leaf.c

@@ -1415,6 +1415,28 @@ xfs_attr3_leaf_create(
 	return 0;
 }
 
+/*
+ * Reinitialize an existing attr fork block as an empty leaf, and attach
+ * the buffer to tp.
+ */
+int
+xfs_attr3_leaf_init(
+	struct xfs_trans	*tp,
+	struct xfs_inode	*dp,
+	xfs_dablk_t		blkno)
+{
+	struct xfs_buf		*bp = NULL;
+	struct xfs_da_args	args = {
+		.trans		= tp,
+		.dp		= dp,
+		.owner		= dp->i_ino,
+		.geo		= dp->i_mount->m_attr_geo,
+	};
+
+	ASSERT(tp != NULL);
+
+	return xfs_attr3_leaf_create(&args, blkno, &bp);
+}
 /*
  * Split the leaf node, rebalance, then add the new entry.
  *

fs/xfs/libxfs/xfs_attr_leaf.h

@@ -87,6 +87,9 @@ int	xfs_attr3_leaf_list_int(struct xfs_buf *bp,
 /*
  * Routines used for shrinking the Btree.
  */
+
+int	xfs_attr3_leaf_init(struct xfs_trans *tp, struct xfs_inode *dp,
+				xfs_dablk_t blkno);
 int	xfs_attr3_leaf_toosmall(struct xfs_da_state *state, int *retval);
 void	xfs_attr3_leaf_unbalance(struct xfs_da_state *state,
 				       struct xfs_da_state_blk *drop_blk,