maple_tree: Fix mas_find search.

There was a bug when a null occurred in a non-leaf node.  This commit
addresses that issue as well as trying to fix dead node detection.

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 7044673725097914b5d3e148cbc461c8481a1841..06041c4041fea5858905fe3d28d273ef7693db14 100644 (file)
--- a/include/linux/maple_tree.h
+++ b/include/linux/maple_tree.h
@@ -402,6 +402,7 @@ static inline void mas_set_range(struct ma_state *mas, unsigned long start,
  */
 static inline void mas_set(struct ma_state *mas, unsigned long index)
 {
+
        mas_set_range(mas, index, index);
 }
 #endif

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index dd0360f634f935352b70862f26206dd034e09bcf..8df4eae5e6868af3f9366812565c598513cfde26 100644 (file)
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -3437,12 +3437,22 @@ static inline int mas_safe_slot(struct ma_state *mas, unsigned char *slot,
        return false;
 }
 
-static inline int mas_dead_node(struct ma_state *mas, unsigned long index)
+static inline bool mas_searchable(struct ma_state *mas)
 {
-       if (mas->node == MAS_NONE)
-               return 0;
-
        if (!mas->node)
+               return false;
+
+       if (mas_is_none(mas))
+               return false;
+
+       if (mas_is_ptr(mas))
+               return false;
+
+       return true;
+}
+static inline int mas_dead_node(struct ma_state *mas, unsigned long index)
+{
+       if (!mas_searchable(mas))
                return 0;
 
        if (!mte_dead_node(mas->node))
@@ -3477,51 +3487,60 @@ void *mas_find(struct ma_state *mas, unsigned long max)
        void *entry = NULL;
        unsigned long last_piv;
        unsigned char slot = 0;
+       unsigned char start_index = mas->index;
 
-       if (!mas->node)
+       if (!mas_searchable(mas))
                goto not_found;
 
-       if (mas_is_start(mas)) {
-               if (!_mas_walk(mas))
-                       return NULL;
+       do {
+               if (mas_is_start(mas)) {
+                       _mas_walk(mas);
+                       if (mas_is_ptr(mas))
+                               entry = mas->tree->ma_root;
 
-               if (mas->node == MAS_ROOT)
-                       return mas->tree->ma_root;
+                       if (mas_is_none(mas))
+                               goto not_found;
 
-               do {} while (mas_dead_node(mas, mas->index));
+                       slot = mas_get_slot(mas);
 
-               if (mas->node == MAS_NONE)
-                       goto not_found;
+                       if (slot != MAPLE_NODE_SLOTS)
+                               entry = mte_get_rcu_slot(mas->node, slot);
 
-               slot = mas_get_slot(mas);
+                       if (mt_is_empty(entry)) {
+                               last_piv = mas_safe_next_entry(mas, max);
+                               if (mas_is_none(mas))
+                                       goto not_found;
 
-               last_piv = mas_get_safe_pivot(mas, slot);
-               if (slot != MAPLE_NODE_SLOTS)
-                       entry = mte_get_rcu_slot(mas->node, slot);
+                               if (!mte_is_leaf(mas->node)) {
+                                       mas_set_slot(mas, 0);
+                                       last_piv = mas_first_entry(mas, max);
+                               }
+                               entry = mte_get_rcu_slot(mas->node, slot);
+                       } else {
+                               last_piv = mas_get_safe_pivot(mas, slot);
+                       }
 
-               if (entry) {
-                       mas->index = last_piv;
+                       mas->index = mas_get_prev_pivot(mas, slot) + 1;
                        if (last_piv)
                                mas->index--;
-                       goto done;
-               }
-       }
-       if (mas->node == MAS_ROOT)
-               goto not_found;
+               } else {
 
-       last_piv = mas_safe_next_entry(mas, max);
-       if (mas->node == MAS_NONE)
-               goto not_found;
+                       last_piv = mas_safe_next_entry(mas, max);
+                       if (mas_is_none(mas))
+                               goto not_found;
 
 
-       slot = mas_get_slot(mas);
-       entry = mte_get_rcu_slot(mas->node, slot);
-       if (!entry)
-               goto not_found;
+                       slot = mas_get_slot(mas);
+                       entry = mte_get_rcu_slot(mas->node, slot);
 
+                       if (!entry)
+                               goto not_found;
+
+
+                       mas->index = mas_get_prev_pivot(mas, slot) + 1;
+               }
+       } while (mas_dead_node(mas, start_index));
 
-       mas->index = mas_get_prev_pivot(mas, slot) + 1;
-done:
        mas->last = last_piv;
        mas_set_slot(mas, slot + 1);
        return entry;
@@ -3567,39 +3586,38 @@ void *mt_find(struct maple_tree *mt, unsigned long start,
        rcu_read_lock();
        _mas_walk(&mas);
 
-       if (mas_is_none(&mas))
-               goto done;
-
-       if (mas_is_ptr(&mas)) {
-               if (!start)
-                       entry = mas.tree->ma_root;
-               goto done;
-       }
-
-       do {} while (mas_dead_node(&mas, mas.index));
-
-       slot = mas_get_slot(&mas);
-       if (slot != MAPLE_NODE_SLOTS)
-               entry = mte_get_rcu_slot(mas.node, slot);
-
+       do {
+               if (mas_is_none(&mas))
+                       goto done;
 
-       if (xa_is_zero(entry))
-               entry = NULL;
+               if (mas_is_ptr(&mas)) {
+                       if (!start)
+                               entry = mas.tree->ma_root;
+                       goto done;
+               }
 
-       if (entry)
-               goto done;
+               slot = mas_get_slot(&mas);
+               if (slot != MAPLE_NODE_SLOTS)
+                       entry = mte_get_rcu_slot(mas.node, slot);
 
 retry:
-       mas_safe_next_entry(&mas, max);
-       if (mas_is_none(&mas))
-               goto done;
-
+               if (xa_is_zero(entry))
+                       entry = NULL;
 
-       slot = mas_get_slot(&mas);
-       entry = mte_get_rcu_slot(mas.node, slot);
-       if (xa_is_zero(entry))
-               goto retry;
+               if (mt_is_advanced(entry)) {
+                       mas_safe_next_entry(&mas, max);
+                       if (mas_is_none(&mas)) {
+                               entry = NULL;
+                       } else if (!mte_is_leaf(mas.node)) {
+                               mas_set_slot(&mas, 0);
+                               mas_first_entry(&mas, max);
+                       }
 
+                       slot = mas_get_slot(&mas);
+                       entry = mte_get_rcu_slot(mas.node, slot);
+                       goto retry;
+               }
+       } while (mas_dead_node(&mas, mas.index));
 done:
        rcu_read_unlock();