ascend function cleanups

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

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index 125556c70b0d5d42c16b9678985f3881c47b47ab..311fb58d9a5f8a3771d153718afbd69f61615af8 100644 (file)
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -2807,8 +2807,11 @@ static inline void cp_dst_to_slots(struct maple_copy *cp, unsigned long min,
        cp->max = max;
 }
 
-static inline void cp_new_root(struct maple_copy *cp, struct ma_state *mas)
+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;
 
@@ -2829,6 +2832,18 @@ static inline void cp_new_root(struct maple_copy *cp, struct ma_state *mas)
        cp->dst[0].node->parent = ma_parent_ptr(mas_tree_parent(mas));
        while (!mte_is_root(mas->node))
                mas_ascend(mas);
+
+       return true;
+}
+
+static inline bool cp_converged(struct maple_copy *cp, struct ma_state *mas,
+                               struct ma_state *sib)
+{
+       if (cp->d_count != 1 || sib->end)
+               return false;
+
+       cp->dst[0].node->parent = ma_parent_ptr(mas_mn(mas)->parent);
+       return true;
 }
 
 static bool spanning_ascend(struct maple_copy *cp, struct ma_state *mas,
@@ -2843,10 +2858,8 @@ 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) {
-               cp_new_root(cp, mas);
+       if (cp_is_new_root(cp, mas))
                return false;
-       }
 
        /* Converged and has a single destination */
        if ((cp->d_count == 1) &&
@@ -2855,15 +2868,9 @@ static bool spanning_ascend(struct maple_copy *cp, struct ma_state *mas,
                return false;
        }
 
-       MAS_WR_BUG_ON(l_wr_mas, cp->height > 4);
        cp->height++;
        wr_mas_ascend(l_wr_mas);
        wr_mas_ascend(r_wr_mas);
-       /*
-        * cp->slot[0] should go in l_wr_mas->offset
-        * cp->slot[end] should go in r_wr_mas->offset
-        */
-
        return true;
 }
 
@@ -2899,7 +2906,8 @@ static void mas_wr_spanning_rebalance(struct ma_state *mas,
  * rebalance_ascend() - Ascend the tree and set up for the next loop - if
  * necessary
  *
- * Returns: True if there is more rebalancing to do, false otherwise.
+ * Return: True if there another rebalancing operation on the next level is
+ * needed, false otherwise.
  */
 static inline bool rebalance_ascend(struct maple_copy *cp,
                struct ma_wr_state *wr_mas, struct ma_state *sib)
@@ -2921,17 +2929,12 @@ static inline bool rebalance_ascend(struct maple_copy *cp,
        }
 
        cp_dst_to_slots(cp, min, r->max, mas);
-       if (!cp->min && cp->max == ULONG_MAX) {
-               cp_new_root(cp, mas);
+       if (cp_is_new_root(cp, mas))
                return false;
-       }
 
-       if (cp->d_count == 1 && !sib->end) {
-               cp->dst[0].node->parent = ma_parent_ptr(mas_mn(mas)->parent);
+       if (cp_converged(cp, mas, sib))
                return false;
-       }
 
-       MAS_WR_BUG_ON(wr_mas, cp->height > 4);
        cp->height++;
        mas_ascend(mas);
        wr_mas_setup(wr_mas, mas);
@@ -3687,6 +3690,15 @@ static inline void mas_wr_append(struct ma_wr_state *wr_mas,
        return;
 }
 
+/*
+ * split_ascend() - See if a split operation has to keep walking up the tree
+ * @cp: The maple_copy node
+ * @wr_mas: The maple write state
+ * @sib: the maple state of the sibling
+ *
+ * Return: true if another split operation on the next level is needed, false
+ * otherwise
+ */
 static bool split_ascend(struct maple_copy *cp,
                struct ma_wr_state *wr_mas, struct ma_state *sib)
 {
@@ -3704,15 +3716,11 @@ static bool split_ascend(struct maple_copy *cp,
        }
 
        cp_dst_to_slots(cp, min, max, mas);
-       if (!cp->min && cp->max == ULONG_MAX) {
-               cp_new_root(cp, mas);
+       if (cp_is_new_root(cp, mas))
                return false;
-       }
 
-       if (cp->d_count == 1 && !sib->end) {
-               cp->dst[0].node->parent = ma_parent_ptr(mas_mn(mas)->parent);
+       if (cp_converged(cp, mas, sib))
                return false;
-       }
 
        cp->height++;
        mas_ascend(mas);