1 files changed, 45 insertions, 0 deletions

diff --git a/fs/xfs/xfs_alloc_btree.c b/fs/xfs/xfs_alloc_btree.c
index 3ce2645508ae..60c121f1e81b 100644
--- a/fs/xfs/xfs_alloc_btree.c
+++ b/fs/xfs/xfs_alloc_btree.c
@@ -2209,3 +2209,48 @@ xfs_alloc_update(
         }
         return 0;
 }
+
+STATIC struct xfs_btree_cur *
+xfs_allocbt_dup_cursor(
+        struct xfs_btree_cur    *cur)
+{
+        return xfs_allocbt_init_cursor(cur->bc_mp, cur->bc_tp,
+                        cur->bc_private.a.agbp, cur->bc_private.a.agno,
+                        cur->bc_btnum);
+}
+
+static const struct xfs_btree_ops xfs_allocbt_ops = {
+        .dup_cursor             = xfs_allocbt_dup_cursor,
+};
+
+/*
+ * Allocate a new allocation btree cursor.
+ */
+struct xfs_btree_cur *                  /* new alloc btree cursor */
+xfs_allocbt_init_cursor(
+        struct xfs_mount        *mp,            /* file system mount point */
+        struct xfs_trans        *tp,            /* transaction pointer */
+        struct xfs_buf          *agbp,          /* buffer for agf structure */
+        xfs_agnumber_t          agno,           /* allocation group number */
+        xfs_btnum_t             btnum)          /* btree identifier */
+{
+        struct xfs_agf          *agf = XFS_BUF_TO_AGF(agbp);
+        struct xfs_btree_cur    *cur;
+
+        ASSERT(btnum == XFS_BTNUM_BNO || btnum == XFS_BTNUM_CNT);
+
+        cur = kmem_zone_zalloc(xfs_btree_cur_zone, KM_SLEEP);
+
+        cur->bc_tp = tp;
+        cur->bc_mp = mp;
+        cur->bc_nlevels = be32_to_cpu(agf->agf_levels[btnum]);
+        cur->bc_btnum = btnum;
+        cur->bc_blocklog = mp->m_sb.sb_blocklog;
+
+        cur->bc_ops = &xfs_allocbt_ops;
+
+        cur->bc_private.a.agbp = agbp;
+        cur->bc_private.a.agno = agno;
+
+        return cur;
+}