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/20230711035444.526-7-zhangpeng.00@bytedance.com
Signed-off-by: Peng Zhang <zhangpeng.00@bytedance.com>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index 31ac4f2..e08ef44 100644 (file)
--- 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);