From: Liam R. Howlett <Liam.Howlett@Oracle.com>
Date: Thu, 29 Oct 2020 19:11:39 +0000 (-0400)
Subject: maple_tree: Fix _mas_store() expand null
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=d642d6a6db8b60f76c34465ea70ca8e36df6c006;p=users%2Fjedix%2Flinux-maple.git

maple_tree: Fix _mas_store() expand null

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

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index ce4c0d15deb7..b58d84fd2134 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -3315,29 +3315,33 @@ static inline void *_mas_store(struct ma_state *mas, void *entry, bool overwrite
 				mas->last = r_max;
 			// if this one is null the next and prev are not.
 		} else {
-			// Check prev slot if we are overwriting the start.
-			if (mas->index == r_min && mas->offset &&
-			    !slots[mas->offset - 1]) {
-				mas->offset--;
-				r_min = mas->index = mas_safe_min(mas, pivots,
-								  mas->offset);
-				r_max = pivots[mas->offset];
-			}
-
 			// Check next slot if we are overwriting the end.
-			if (mas->last == r_max && !slots[mas->offset + 1]) {
-				mas->last = pivots[mas->offset + 1];
-			}
-			else if (mas->last > r_max) { // expand over this slot if necessary.
+			if ((mas->last == r_max) && !slots[mas->offset + 1]) {
+				if (mas->offset < mt_pivots[mt] - 1 &&
+				    pivots[mas->offset + 1])
+					mas->last = pivots[mas->offset + 1];
+				else
+					mas->last = mas->max;
+			} else if (mas->last > r_max) { // expand over this slot if necessary.
 				unsigned long piv;
+
 				do {
 					piv = _mas_safe_pivot(mas, pivots,
 							      ++offset_end, mt);
-				} while (mas->last > piv);
+				} while (mas->last >= piv);
 
 				if (!slots[offset_end])
 					mas->last = piv;
 			}
+
+			// Check prev slot if we are overwriting the start.
+			if (mas->index == r_min && mas->offset &&
+			    !slots[mas->offset - 1]) {
+				mas->offset--;
+				r_min = mas->index = mas_safe_min(mas, pivots,
+								  mas->offset);
+				r_max = pivots[mas->offset];
+			}
 		}
 	}