maple_tree: Add cp_is_new_root() helper

Add a helper to do what is needed when the maple copy node contains a
new root node.  This is useful for future commits and is
self-documenting code.

Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index 992b824c3610752a0f5311b488c69152be7ad3c2..78468d8b7865190f9642cbc3741098bb1221d17f 100644 (file)
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -3532,6 +3532,36 @@ static void mas_spanning_rebalance(struct ma_state *mas,
        mas_spanning_rebalance_loop(mas, mast, count);
 }
 
+static inline bool cp_is_new_root(struct maple_copy *cp, struct ma_state *mas)
+{
+       if (cp->min || cp->max != ULONG_MAX)
+               return false;
+
+       if (cp->d_count != 1) {
+               enum maple_type mt = maple_arange_64;
+
+               if (!mt_is_alloc(mas->tree))
+                       mt = maple_range_64;
+
+               cp->data = cp->d_count;
+               cp->s_count = 0;
+               dst_setup(cp, mas, mt);
+               init_cp_src(cp);
+               node_copy(mas, cp->src[0].node, 0, cp->data, cp->max, maple_copy,
+                         cp->dst[0].node, 0, mt);
+               node_finalise(cp->dst[0].node, mt, cp->end + 1);
+               cp->slot[0] = mt_mk_node(cp->dst[0].node, mt);
+               cp->height++;
+       }
+       WARN_ON_ONCE(cp->dst[0].node != mte_to_node(cp->slot[0]));
+       cp->dst[0].node->parent = ma_parent_ptr(mas_tree_parent(mas));
+       mas->min = 0;
+       mas->max = ULONG_MAX;
+       mas->depth = 0;
+       mas->node = mas_root_locked(mas);
+       return true;
+}
+
 /*
  * spanning_ascend() - See if a spanning store operation has to keep walking up
  * the tree
@@ -3554,32 +3584,8 @@ static bool spanning_ascend(struct maple_copy *cp, struct ma_state *mas,
        }
 
        cp_dst_to_slots(cp, l_wr_mas->mas->min, r_wr_mas->mas->max, mas);
-       if (!cp->min && cp->max == ULONG_MAX) {
-               /* New root */
-               if (cp->d_count != 1) {
-                       enum maple_type mt = maple_arange_64;
-
-                       if (!mt_is_alloc(mas->tree))
-                               mt = maple_range_64;
-
-                       cp->data = cp->d_count;
-                       cp->s_count = 0;
-                       dst_setup(cp, mas, mt);
-                       init_cp_src(cp);
-                       node_copy(mas, cp->src[0].node, 0, cp->data, cp->max, maple_copy,
-                                 cp->dst[0].node, 0, mt);
-                       node_finalise(cp->dst[0].node, mt, cp->end + 1);
-                       cp->slot[0] = mt_mk_node(cp->dst[0].node, mt);
-                       cp->height++;
-               }
-               WARN_ON_ONCE(cp->dst[0].node != mte_to_node(cp->slot[0]));
-               cp->dst[0].node->parent = ma_parent_ptr(mas_tree_parent(mas));
-               mas->min = 0;
-               mas->max = ULONG_MAX;
-               mas->depth = 0;
-               mas->node = mas_root_locked(mas);
+       if (cp_is_new_root(cp, mas))
                return false;
-       }
 
        /* Converged and has a single destination */
        if ((cp->d_count == 1) &&