Commit 5159d64b authored by Liam R. Howlett's avatar Liam R. Howlett Committed by Andrew Morton
Browse files

test_maple_tree: test modifications while iterating 

Add a testcase to ensure the iterator detects bad states on modifications
and does what the user expects

Link: https://lkml.kernel.org/r/20230120162650.984577-5-Liam.Howlett@oracle.com


Signed-off-by: default avatarLiam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 50e81c82

lib/test_maple_tree.c

+72 −0
Original line number Diff line number Diff line
@@ -1709,6 +1709,74 @@ static noinline void check_forking(struct maple_tree *mt) 
	mtree_destroy(&newmt);

}



static noinline void check_iteration(struct maple_tree *mt)

{

	int i, nr_entries = 125;

	void *val;

	MA_STATE(mas, mt, 0, 0);



	for (i = 0; i <= nr_entries; i++)

		mtree_store_range(mt, i * 10, i * 10 + 9,

				  xa_mk_value(i), GFP_KERNEL);



	mt_set_non_kernel(99999);



	i = 0;

	mas_lock(&mas);

	mas_for_each(&mas, val, 925) {

		MT_BUG_ON(mt, mas.index != i * 10);

		MT_BUG_ON(mt, mas.last != i * 10 + 9);

		/* Overwrite end of entry 92 */

		if (i == 92) {

			mas.index = 925;

			mas.last = 929;

			mas_store(&mas, val);

		}

		i++;

	}

	/* Ensure mas_find() gets the next value */

	val = mas_find(&mas, ULONG_MAX);

	MT_BUG_ON(mt, val != xa_mk_value(i));



	mas_set(&mas, 0);

	i = 0;

	mas_for_each(&mas, val, 785) {

		MT_BUG_ON(mt, mas.index != i * 10);

		MT_BUG_ON(mt, mas.last != i * 10 + 9);

		/* Overwrite start of entry 78 */

		if (i == 78) {

			mas.index = 780;

			mas.last = 785;

			mas_store(&mas, val);

		} else {

			i++;

		}

	}

	val = mas_find(&mas, ULONG_MAX);

	MT_BUG_ON(mt, val != xa_mk_value(i));



	mas_set(&mas, 0);

	i = 0;

	mas_for_each(&mas, val, 765) {

		MT_BUG_ON(mt, mas.index != i * 10);

		MT_BUG_ON(mt, mas.last != i * 10 + 9);

		/* Overwrite end of entry 76 and advance to the end */

		if (i == 76) {

			mas.index = 760;

			mas.last = 765;

			mas_store(&mas, val);

			mas_next(&mas, ULONG_MAX);

		}

		i++;

	}

	/* Make sure the next find returns the one after 765, 766-769 */

	val = mas_find(&mas, ULONG_MAX);

	MT_BUG_ON(mt, val != xa_mk_value(76));

	mas_unlock(&mas);

	mas_destroy(&mas);

	mt_set_non_kernel(0);

}



static noinline void check_mas_store_gfp(struct maple_tree *mt)

{
@@ -2659,6 +2727,10 @@ static int maple_tree_seed(void) 
	goto skip;

#endif



	mt_init_flags(&tree, MT_FLAGS_ALLOC_RANGE);

	check_iteration(&tree);

	mtree_destroy(&tree);



	mt_init_flags(&tree, MT_FLAGS_ALLOC_RANGE);

	check_forking(&tree);

	mtree_destroy(&tree);