From 5b2100f723bd5c2b5552b27208f3e7d7447910d3 Mon Sep 17 00:00:00 2001 From: Jiazi Li Date: Wed, 26 Jun 2024 12:06:30 -0400 Subject: [PATCH] maple_tree: fix alloc node fail issue In the following code, the second call to the mas_node_count will return -ENOMEM: mas_node_count(mas, MAPLE_ALLOC_SLOTS + 1); mas_node_count(mas, MAPLE_ALLOC_SLOTS * 2 + 2); This is because there may be some full maple_alloc node in current maple state. Use full maple_alloc node will make max_req equal to 0. And it leads to mt_alloc_bulk return 0. As a result, mas_node_count set mas.node to MA_ERROR(-ENOMEM). Find a non-full maple_alloc node, and if necessary, use this non-full node in the next while loop. Link: https://lkml.kernel.org/r/20240626160631.3636515-1-Liam.Howlett@oracle.com Fixes: 54a611b60590 ("Maple Tree: add new data structure") Signed-off-by: Jiazi Li Signed-off-by: Liam R. Howlett Suggested-by: Liam R. Howlett Reviewed-by: Wei Yang Signed-off-by: Andrew Morton --- lib/maple_tree.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/lib/maple_tree.c b/lib/maple_tree.c index a5e982e482dd..cdac15168405 100644 --- a/lib/maple_tree.c +++ b/lib/maple_tree.c @@ -1285,7 +1285,10 @@ static inline void mas_alloc_nodes(struct ma_state *mas, gfp_t gfp) node->node_count += count; allocated += count; - node = node->slot[0]; + /* find a non-full node*/ + do { + node = node->slot[0]; + } while (unlikely(node->node_count == MAPLE_ALLOC_SLOTS)); requested -= count; } mas->alloc->total = allocated; -- 2.25.1