From: Liam R. Howlett <Liam.Howlett@Oracle.com>
Date: Thu, 10 Jan 2019 19:05:43 +0000 (-0500)
Subject: maple_tree: Change ma_coalesce to return the number of slots removed.
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=f67fa28bef6485e2e82111d6883dfd34ffa586c3;p=users%2Fjedix%2Flinux-maple.git

maple_tree: Change ma_coalesce to return the number of slots removed.

Set ma->node to the new node, so save the previous node before calling
the function.  Also fix an off-by-one error in ma_coalesce.

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

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index f90fd7f5b025..e2586362caaa 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -438,27 +438,28 @@ static void mas_update_limits(struct ma_state *ms, unsigned char slot)
 /* Private
  * Combine nulls with the same pivot value
  */
-static void *mas_coalesce(struct ma_state *mas)
+static int mas_coalesce(struct ma_state *mas)
 {
 	struct maple_range_64 *src = &mt_to_node(mas->node)->mr64;
+	unsigned char s_slot, d_slot = 0;
 	unsigned long last = mas->max;
 	struct maple_range_64 *dst;
 	struct maple_node *mn;
-	unsigned char s_slot, d_slot = 0;
 
 	/* Allocate a new node */
 	mas_node_cnt(mas, 1);
 	if (mas_is_err(mas))
-		return NULL;
+		return 0;
 
 	mn = ma_next_alloc(mas);
 	dst = &mn->mr64;
+	mas->node = mt_mk_node(mn, maple_leaf_64);
 
-	for (s_slot = 0; s_slot < MAPLE_RANGE64_SLOTS - 1; s_slot++) {
-		if (last == src->pivot[s_slot])
-			continue;
-
+	for (s_slot = 0; s_slot < MAPLE_RANGE64_SLOTS; s_slot++) {
 		if (s_slot < MAPLE_RANGE64_SLOTS - 1) {
+			if (last == src->pivot[s_slot])
+				continue;
+
 			if (s_slot != 0 && src->pivot[s_slot] == 0)
 				break;
 
@@ -468,7 +469,7 @@ static void *mas_coalesce(struct ma_state *mas)
 		RCU_INIT_POINTER(dst->slot[d_slot], src->slot[s_slot]);
 		last = dst->pivot[d_slot++];
 	}
-	return mn;
+	return s_slot - d_slot;
 }
 
 static void ma_adopt_children(struct maple_node *parent)
@@ -582,7 +583,6 @@ void *ma_insert(struct ma_state *mas, void *entry)
 {
 	void *p_entry; // Previous entry.
 	unsigned char slot = MAPLE_NODE_SLOTS;
-	struct maple_node *mn;
 	bool leaf;
 
 
@@ -612,13 +612,11 @@ void *ma_insert(struct ma_state *mas, void *entry)
 		}
 	}
 
-	mn = mas_coalesce(mas);
+	p_entry = mas->node;
+	mas_coalesce(mas);
 	if (mas_is_err(mas))
 		goto error;
 
-	p_entry = mas->node;
-
-	mas->node = mt_mk_node(mn, maple_leaf_64);
 	/* Do the insert */
 	_ma_insert(mas, entry, slot);
 	if (mas_is_err(mas))
@@ -685,7 +683,6 @@ int ma_erase(struct ma_state *mas)
 	unsigned long piv_val;
 	int cnt = -EINVAL;
 	void *p_entry; // Previous entry.
-	struct maple_node *mn;
 
 	if (slot == MAPLE_NODE_SLOTS)
 		return cnt;
@@ -707,12 +704,10 @@ int ma_erase(struct ma_state *mas)
 		mr64->pivot[slot] = piv_val;
 		cnt++;
 	}
-
-	mn = mas_coalesce(mas);
+	p_entry = mas->node;
+	mas_coalesce(mas);
 	if (mas_is_err(mas))
 		goto error;
-	p_entry = mas->node;
-	mas->node = mt_mk_node(mn, maple_leaf_64);
 	mt_replace(mas, p_entry, leaf);
 
 error: