[PATCH] maple_tree: Fix sparse reported issues

Liam Howlett
2022-07-12T14:25:02Z

When building with C=1, the maple tree had some rcu type mismatch &
locking mismatches in the destroy functions. There were cosmetic only
since this happens after the nodes are removed from the tree.

Fixes: f8acc5e9581e (Maple Tree: add new data structure)
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
---
lib/maple_tree.c | 16 +++++++++++-----
1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index 79e07c7dc323..9dc4ffff18d0 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -2319,7 +2319,7 @@ static inline void mast_topiary(struct maple_subtree_state *mast)
MA_WR_STATE(wr_mas, mast->orig_l, NULL);
unsigned char r_start, r_end;
unsigned char l_start, l_end;
- void **l_slots, **r_slots;
+ void __rcu **l_slots, **r_slots;

wr_mas.type = mte_node_type(mast->orig_l->node);
mast->orig_l->index = mast->orig_l->last;
@@ -5461,6 +5461,7 @@ static void mt_free_walk(struct rcu_head *head)
mt_free_bulk(node->slot_len, slots);

start_slots_free:
+ mas_unlock(&mas);
free_leaf:
mt_free_rcu(&node->rcu);
}
@@ -5513,6 +5514,7 @@ static void mt_destroy_walk(struct maple_enode *enode, unsigned char ma_flags,
do {
enum maple_type type;
unsigned char offset;
+ struct maple_enode *parent, *tmp;

node->slot_len = mas_dead_leaves(&mas, slots);
if (free)
@@ -5524,13 +5526,17 @@ static void mt_destroy_walk(struct maple_enode *enode, unsigned char ma_flags,

type = mte_node_type(mas.node);
slots = ma_slots(mte_to_node(mas.node), type);
- if ((offset < mt_slots[type]) && mte_node_type(slots[offset]) &&
- mte_to_node(slots[offset])) {
- struct maple_enode *parent = mas.node;
+ if (offset >= mt_slots[type])
+ goto next;

- mas.node = mas_slot_locked(&mas, slots, offset);
+ tmp = mas_slot_locked(&mas, slots, offset);
+ if (mte_node_type(tmp) && mte_to_node(tmp)) {
+
+ parent = mas.node;
+ mas.node = tmp;
slots = mas_destroy_descend(&mas, parent, offset);
}
+next:
node = mas_mn(&mas);
} while (start != mas.node);

--
2.35.1