Commit 5b2100f7 authored by Jiazi Li's avatar Jiazi Li Committed by Andrew Morton
Browse files

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: 54a611b6 ("Maple Tree: add new data structure")
Signed-off-by: default avatarJiazi Li <jqqlijiazi@gmail.com>
Signed-off-by: default avatarLiam R. Howlett <Liam.Howlett@oracle.com>
Suggested-by: default avatarLiam R. Howlett <Liam.Howlett@oracle.com>
Reviewed-by: default avatarWei Yang <richard.weiyang@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent f69c2e4d

lib/maple_tree.c

+4 −1
Original line number Diff line number Diff line
@@ -1285,7 +1285,10 @@ static inline void mas_alloc_nodes(struct ma_state *mas, gfp_t gfp) 


		node->node_count += count;

		allocated += count;

		/* find a non-full node*/

		do {

			node = node->slot[0];

		} while (unlikely(node->node_count == MAPLE_ALLOC_SLOTS));

		requested -= count;

	}

	mas->alloc->total = allocated;