Commit b02fcc08 authored by Liam R. Howlett's avatar Liam R. Howlett Committed by Andrew Morton
Browse files

test_maple_tree: test exhausted upper limit of mtree_alloc_cyclic() 

When the upper bound of the search is exhausted, the maple state may be
returned in an error state of -EBUSY.  This means maple state needs to be
reset before the second search in mas_alloc_cylic() to ensure the search
happens.  This test ensures the issue is not recreated.

Link: https://lkml.kernel.org/r/20241216190113.1226145-3-Liam.Howlett@oracle.com


Signed-off-by: default avatarLiam R. Howlett <Liam.Howlett@Oracle.com>
Reviewed-by: default avatarYang Erkun <yangerkun@huawei.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Chuck Lever <chuck.lever@oracle.com> says:
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent e2c9e619

lib/test_maple_tree.c

+28 −0
Original line number Diff line number Diff line
@@ -3738,6 +3738,34 @@ static noinline void __init alloc_cyclic_testing(struct maple_tree *mt) 
	}



	mtree_destroy(mt);



	/*

	 * Issue with reverse search was discovered

	 * https://lore.kernel.org/all/20241216060600.287B4C4CED0@smtp.kernel.org/

	 * Exhausting the allocation area and forcing the search to wrap needs a

	 * mas_reset() in mas_alloc_cyclic().

	 */

	next = 0;

	mt_init_flags(mt, MT_FLAGS_ALLOC_RANGE);

	for (int i = 0; i < 1023; i++) {

		mtree_alloc_cyclic(mt, &location, mt, 2, 1024, &next, GFP_KERNEL);

		MT_BUG_ON(mt, i != location - 2);

		MT_BUG_ON(mt, i != next - 3);

		MT_BUG_ON(mt, mtree_load(mt, location) != mt);

	}

	mtree_erase(mt, 123);

	MT_BUG_ON(mt, mtree_load(mt, 123) != NULL);

	mtree_alloc_cyclic(mt, &location, mt, 2, 1024, &next, GFP_KERNEL);

	MT_BUG_ON(mt, 123 != location);

	MT_BUG_ON(mt, 124 != next);

	MT_BUG_ON(mt, mtree_load(mt, location) != mt);

	mtree_erase(mt, 100);

	mtree_alloc_cyclic(mt, &location, mt, 2, 1024, &next, GFP_KERNEL);

	MT_BUG_ON(mt, 100 != location);

	MT_BUG_ON(mt, 101 != next);

	MT_BUG_ON(mt, mtree_load(mt, location) != mt);

	mtree_destroy(mt);



	/* Overflow test */

	next = ULONG_MAX - 1;

	ret = mtree_alloc_cyclic(mt, &location, mt, 2, ULONG_MAX, &next, GFP_KERNEL);