From: Liam R. Howlett <Liam.Howlett@Oracle.com>
Date: Fri, 6 Nov 2020 21:52:59 +0000 (-0500)
Subject: maple_tree: Add mas_store_gfp() and fix mas_prev() and mas_store()
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=5112428a959bfdba6205f8182e42c059430469b0;p=users%2Fjedix%2Flinux-maple.git

maple_tree: Add mas_store_gfp() and fix mas_prev() and mas_store()

When searching for the previous value, walk the node first.  Don't just assume we are looking for the
last entry if it's MAS_START.

mas_store() and mas_destroy() now workk better with MAS_START as well.

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

diff --git a/include/linux/maple_tree.h b/include/linux/maple_tree.h
index 496e539bc54e..06506c529fd7 100644
--- a/include/linux/maple_tree.h
+++ b/include/linux/maple_tree.h
@@ -244,6 +244,7 @@ struct ma_state {
 
 void *mas_walk(struct ma_state *mas);
 void *mas_store(struct ma_state *mas, void *entry);
+int mas_store_gfp(struct ma_state *mas, void *entry, gfp_t gfp);
 void *mas_find(struct ma_state *mas, unsigned long max);
 
 bool mas_nomem(struct ma_state *mas, gfp_t gfp);
diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index a6e8736b312c..6b5284db50af 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -3808,9 +3808,10 @@ void *mas_prev(struct ma_state *mas, unsigned long min)
 	if (!mas_searchable(mas))
 		return NULL;
 
+
 	if (mas_is_start(mas)) {
 		mas_start(mas);
-		return mas_last_entry(mas, ULONG_MAX);
+		mas_walk(mas);
 	}
 
 	do {
@@ -4910,14 +4911,49 @@ EXPORT_SYMBOL(mtree_destroy);
  */
 void *mas_store(struct ma_state *mas, void *entry)
 {
-	if (mas->index <= mas->last)
-		return _mas_store(mas, entry, true);
+	void *existing = NULL;
+
+	if (mas->index > mas->last)
+		goto invalid_range;
+
+	existing = _mas_store(mas, entry, true);
+	if (mas_is_err(mas))
+		return existing;
+
+	if (!mte_is_leaf(mas->node)) // gaps were updated
+		mas->node = MAS_START;
 
+	return existing;
+
+invalid_range:
 	mas_set_err(mas, -EINVAL);
 	return NULL;
 
 }
 
+int mas_store_gfp(struct ma_state *mas, void *entry, gfp_t gfp)
+{
+
+	// Detect spanning store.
+	if ((mas->last == mas->max && !entry) ||
+	    (mas->last > mas->max))
+		mas->node = MAS_START;
+
+retry:
+	_mas_store(mas, entry, true);
+	if (mas_nomem(mas, gfp))
+		goto retry;
+
+	if (mas_is_err(mas))
+		return xa_err(mas->node);
+
+	if (!mte_is_leaf(mas->node)) // gaps were updated
+		mas->node = MAS_START;
+
+	return 0;
+
+}
+
 /*
  * mas_entry_count() - Set the expected number of entries that will be inserted.
  *
@@ -4981,6 +5017,9 @@ void mas_destroy(struct ma_state *mas)
 		unsigned char end;
 		unsigned long range_min, range_max;
 
+		if (mas_is_start(mas))
+			mas_start(mas);
+
 		__mas_walk(mas, &range_min, &range_max);
 		end = mas_data_end(mas) + 1;
 		if (end < mt_min_slot_count(mas->node) - 1) {