From: Liam R. Howlett <Liam.Howlett@Oracle.com>
Date: Tue, 27 Oct 2020 18:10:59 +0000 (-0400)
Subject: maple_tree: Fix _mas_store() rmin expansion on null.
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=a0c6410a735e4a153cc54e13bf0ff7b44f6871cd;p=users%2Fjedix%2Flinux-maple.git

maple_tree: Fix _mas_store() rmin expansion on null.

When the offset changes on expanding null, ensure the min slot value changes
as well.  This avoids a fall-through to the slow path and uses the
mas_node_store() instead.

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

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index 5ee0a6d96ef4..f2035bb0e3b1 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -3177,9 +3177,8 @@ static inline bool mas_node_store(struct ma_state *mas, void *entry,
 		return false;
 
 	if (!mte_is_root(mas->node) && (new_end <= mt_min_slots[mt]) &&
-	    !(mas->mas_flags & MA_STATE_ADVANCED_OP)) {// not enough data.
+	    !(mas->mas_flags & MA_STATE_ADVANCED_OP)) // not enough data.
 		return false;
-	}
 
 	// set up node.
 	if (mt_in_rcu(mas->tree)) {
@@ -3260,10 +3259,10 @@ static inline bool mas_slot_store(struct ma_state *mas, void *entry,
 	if (offset + 1 >= mt_slots[mt]) // out of room.
 		return false;
 
-	lmax = mas_logical_pivot(mas, pivots, offset + 1, mt);
 	if (max > mas->last) // going to split a single entry.
 		goto try_node_store;
 
+	lmax = mas_logical_pivot(mas, pivots, offset + 1, mt);
 	if (lmax < mas->last) // going to overwrite too many slots.
 		goto try_node_store;
 
@@ -3337,6 +3336,9 @@ static inline void *_mas_store(struct ma_state *mas, void *entry, bool overwrite
 
 	if (!entry) {
 		unsigned long rmin, rmax;
+		enum maple_type mt = mte_node_type(mas->node);
+		unsigned long *pivots = ma_pivots(mas_mn(mas),mt);
+
 		MA_STATE(r_mas, mas->tree, mas->last, mas->last);
 
 		mas_set_offset(&r_mas, offset);
@@ -3346,7 +3348,8 @@ static inline void *_mas_store(struct ma_state *mas, void *entry, bool overwrite
 		mas_extend_null(mas, &r_mas);
 		mas->last = r_mas.last;
 		offset = mas_offset(mas);
-		r_max = mas_safe_pivot(mas, mas_offset(mas));
+		r_min = mas_safe_min(mas, pivots, offset);
+		r_max = _mas_safe_pivot(mas, pivots, offset, mt);
 	}
 
 	end = mas_data_end(mas);