[RFC PATCH 02/11] test_xarray: add tests for advanced multi-index use

[Daniel Gomez <da.gomez@samsung.com>]

From: Luis Chamberlain <mcgrof@kernel.org>

The multi index selftests are great but they don't replicate
how we deal with the page cache exactly, which makes it a bit
hard to follow as the page cache uses the advanced API.

Add tests which use the advanced API, mimicking what we do in the
page cache, while at it, extend the example to do what is needed for
min order support.

Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Tested-by: Daniel Gomez <da.gomez@samsung.com>
---
 lib/test_xarray.c | 134 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 134 insertions(+)

diff --git a/lib/test_xarray.c b/lib/test_xarray.c
index 6c22588963bc..22a687e33dc5 100644
--- a/lib/test_xarray.c
+++ b/lib/test_xarray.c
@@ -694,6 +694,139 @@ static noinline void check_multi_store(struct xarray *xa)
 #endif
 }
 
+#ifdef CONFIG_XARRAY_MULTI
+static noinline void check_xa_multi_store_adv_add(struct xarray *xa,
+						  unsigned long index,
+						  unsigned int order,
+						  void *p)
+{
+	XA_STATE(xas, xa, index);
+
+	xas_set_order(&xas, index, order);
+
+	do {
+		xas_lock_irq(&xas);
+
+		xas_store(&xas, p);
+		XA_BUG_ON(xa, xas_error(&xas));
+		XA_BUG_ON(xa, xa_load(xa, index) != p);
+
+		xas_unlock_irq(&xas);
+	} while (xas_nomem(&xas, GFP_KERNEL));
+
+	XA_BUG_ON(xa, xas_error(&xas));
+}
+
+static noinline void check_xa_multi_store_adv_delete(struct xarray *xa,
+						     unsigned long index,
+						     unsigned int order)
+{
+	unsigned int nrpages = 1UL << order;
+	unsigned long base = round_down(index, nrpages);
+	XA_STATE(xas, xa, base);
+
+	xas_set_order(&xas, base, order);
+	xas_store(&xas, NULL);
+	xas_init_marks(&xas);
+}
+
+static unsigned long some_val = 0xdeadbeef;
+static unsigned long some_val_2 = 0xdeaddead;
+
+/* mimics the page cache */
+static noinline void check_xa_multi_store_adv(struct xarray *xa,
+					      unsigned long pos,
+					      unsigned int order)
+{
+	unsigned int nrpages = 1UL << order;
+	unsigned long index, base, next_index, next_next_index;
+	unsigned int i;
+
+	index = pos >> PAGE_SHIFT;
+	base = round_down(index, nrpages);
+	next_index = round_down(base + nrpages, nrpages);
+	next_next_index = round_down(next_index + nrpages, nrpages);
+
+	check_xa_multi_store_adv_add(xa, base, order, &some_val);
+
+	for (i = 0; i < nrpages; i++)
+		XA_BUG_ON(xa, xa_load(xa, base + i) != &some_val);
+
+	XA_BUG_ON(xa, xa_load(xa, next_index) != NULL);
+
+	/* Use order 0 for the next item */
+	check_xa_multi_store_adv_add(xa, next_index, 0, &some_val_2);
+	XA_BUG_ON(xa, xa_load(xa, next_index) != &some_val_2);
+
+	/* Remove the next item */
+	check_xa_multi_store_adv_delete(xa, next_index, 0);
+
+	/* Now use order for a new pointer */
+	check_xa_multi_store_adv_add(xa, next_index, order, &some_val_2);
+
+	for (i = 0; i < nrpages; i++)
+		XA_BUG_ON(xa, xa_load(xa, next_index + i) != &some_val_2);
+
+	check_xa_multi_store_adv_delete(xa, next_index, order);
+	check_xa_multi_store_adv_delete(xa, base, order);
+	XA_BUG_ON(xa, !xa_empty(xa));
+
+	/* starting fresh again */
+
+	/* let's test some holes now */
+
+	/* hole at base and next_next */
+	check_xa_multi_store_adv_add(xa, next_index, order, &some_val_2);
+
+	for (i = 0; i < nrpages; i++)
+		XA_BUG_ON(xa, xa_load(xa, base + i) != NULL);
+
+	for (i = 0; i < nrpages; i++)
+		XA_BUG_ON(xa, xa_load(xa, next_index + i) != &some_val_2);
+
+	for (i = 0; i < nrpages; i++)
+		XA_BUG_ON(xa, xa_load(xa, next_next_index + i) != NULL);
+
+	check_xa_multi_store_adv_delete(xa, next_index, order);
+	XA_BUG_ON(xa, !xa_empty(xa));
+
+	/* hole at base and next */
+
+	check_xa_multi_store_adv_add(xa, next_next_index, order, &some_val_2);
+
+	for (i = 0; i < nrpages; i++)
+		XA_BUG_ON(xa, xa_load(xa, base + i) != NULL);
+
+	for (i = 0; i < nrpages; i++)
+		XA_BUG_ON(xa, xa_load(xa, next_index + i) != NULL);
+
+	for (i = 0; i < nrpages; i++)
+		XA_BUG_ON(xa, xa_load(xa, next_next_index + i) != &some_val_2);
+
+	check_xa_multi_store_adv_delete(xa, next_next_index, order);
+	XA_BUG_ON(xa, !xa_empty(xa));
+}
+#endif
+
+static noinline void check_multi_store_advanced(struct xarray *xa)
+{
+#ifdef CONFIG_XARRAY_MULTI
+	unsigned int max_order = IS_ENABLED(CONFIG_XARRAY_MULTI) ? 20 : 1;
+	unsigned long end = ULONG_MAX/2;
+	unsigned long pos, i;
+
+	/*
+	 * About 117 million tests below.
+	 */
+	for (pos = 7; pos < end; pos = (pos * pos) + 564) {
+		for (i = 0; i < max_order; i++) {
+			check_xa_multi_store_adv(xa, pos, i);
+			check_xa_multi_store_adv(xa, pos + 157, i);
+		}
+	}
+#endif
+}
+
 static noinline void check_xa_alloc_1(struct xarray *xa, unsigned int base)
 {
 	int i;
@@ -1825,6 +1958,7 @@ static int xarray_checks(void)
 	check_reserve(&array);
 	check_reserve(&xa0);
 	check_multi_store(&array);
+	check_multi_store_advanced(&array);
 	check_get_order(&array);
 	check_xa_alloc();
 	check_find(&array);
-- 
2.39.2