maple_tree: update mt_validate()

Instead of using mas_first_entry() to find the leftmost leaf, use a simple
loop instead.  Remove an unneeded check for root node.  To make the error
message more accurate, check pivots first and then slots, because checking
slots depend on the node limit pivot to break the loop.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Peng Zhang <[email protected]>
Tested-by: Geert Uytterhoeven <[email protected]>
Reviewed-by: Liam R. Howlett <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

1 files changed, 9 insertions, 10 deletions

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index 31ac4f2c4426..e08ef44926c6 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -7244,21 +7244,20 @@ void mt_validate(struct maple_tree *mt)
 	if (!mas_searchable(&mas))
 		goto done;
 
-	mas_first_entry(&mas, mas_mn(&mas), ULONG_MAX, mte_node_type(mas.node));
+	while (!mte_is_leaf(mas.node))
+		mas_descend(&mas);
+
 	while (!mas_is_none(&mas)) {
 		MAS_WARN_ON(&mas, mte_dead_node(mas.node));
-		if (!mte_is_root(mas.node)) {
-			end = mas_data_end(&mas);
-			if (MAS_WARN_ON(&mas,
-					(end < mt_min_slot_count(mas.node)) &&
-					(mas.max != ULONG_MAX))) {
-				pr_err("Invalid size %u of %p\n", end,
-				       mas_mn(&mas));
-			}
+		end = mas_data_end(&mas);
+		if (MAS_WARN_ON(&mas, (end < mt_min_slot_count(mas.node)) &&
+				(mas.max != ULONG_MAX))) {
+			pr_err("Invalid size %u of %p\n", end, mas_mn(&mas));
 		}
+
 		mas_validate_parent_slot(&mas);
-		mas_validate_child_slot(&mas);
 		mas_validate_limits(&mas);
+		mas_validate_child_slot(&mas);
 		if (mt_is_alloc(mt))
 			mas_validate_gaps(&mas);
 		mas_dfs_postorder(&mas, ULONG_MAX);