Merge branch 'xarray' of git://git.infradead.org/users/willy/linux-dax

Pull XArray conversion from Matthew Wilcox:
 "The XArray provides an improved interface to the radix tree data
  structure, providing locking as part of the API, specifying GFP flags
  at allocation time, eliminating preloading, less re-walking the tree,
  more efficient iterations and not exposing RCU-protected pointers to
  its users.

  This patch set

   1. Introduces the XArray implementation

   2. Converts the pagecache to use it

   3. Converts memremap to use it

  The page cache is the most complex and important user of the radix
  tree, so converting it was most important. Converting the memremap
  code removes the only other user of the multiorder code, which allows
  us to remove the radix tree code that supported it.

  I have 40+ followup patches to convert many other users of the radix
  tree over to the XArray, but I'd like to get this part in first. The
  other conversions haven't been in linux-next and aren't suitable for
  applying yet, but you can see them in the xarray-conv branch if you're
  interested"

* 'xarray' of git://git.infradead.org/users/willy/linux-dax: (90 commits)
  radix tree: Remove multiorder support
  radix tree test: Convert multiorder tests to XArray
  radix tree tests: Convert item_delete_rcu to XArray
  radix tree tests: Convert item_kill_tree to XArray
  radix tree tests: Move item_insert_order
  radix tree test suite: Remove multiorder benchmarking
  radix tree test suite: Remove __item_insert
  memremap: Convert to XArray
  xarray: Add range store functionality
  xarray: Move multiorder_check to in-kernel tests
  xarray: Move multiorder_shrink to kernel tests
  xarray: Move multiorder account test in-kernel
  radix tree test suite: Convert iteration test to XArray
  radix tree test suite: Convert tag_tagged_items to XArray
  radix tree: Remove radix_tree_clear_tags
  radix tree: Remove radix_tree_maybe_preload_order
  radix tree: Remove split/join code
  radix tree: Remove radix_tree_update_node_t
  page cache: Finish XArray conversion
  dax: Convert page fault handlers to XArray
  ...

1 files changed, 64 insertions, 545 deletions

diff --git a/tools/testing/radix-tree/multiorder.c b/tools/testing/radix-tree/multiorder.c
index 7bf405638b0b..ff27a74d9762 100644
--- a/tools/testing/radix-tree/multiorder.c
+++ b/tools/testing/radix-tree/multiorder.c
@@ -20,230 +20,39 @@
 
 #include "test.h"
 
-#define for_each_index(i, base, order) \
-	for (i = base; i < base + (1 << order); i++)
-
-static void __multiorder_tag_test(int index, int order)
-{
-	RADIX_TREE(tree, GFP_KERNEL);
-	int base, err, i;
-
-	/* our canonical entry */
-	base = index & ~((1 << order) - 1);
-
-	printv(2, "Multiorder tag test with index %d, canonical entry %d\n",
-			index, base);
-
-	err = item_insert_order(&tree, index, order);
-	assert(!err);
-
-	/*
-	 * Verify we get collisions for covered indices.  We try and fail to
-	 * insert an exceptional entry so we don't leak memory via
-	 * item_insert_order().
-	 */
-	for_each_index(i, base, order) {
-		err = __radix_tree_insert(&tree, i, order,
-				(void *)(0xA0 | RADIX_TREE_EXCEPTIONAL_ENTRY));
-		assert(err == -EEXIST);
-	}
-
-	for_each_index(i, base, order) {
-		assert(!radix_tree_tag_get(&tree, i, 0));
-		assert(!radix_tree_tag_get(&tree, i, 1));
-	}
-
-	assert(radix_tree_tag_set(&tree, index, 0));
-
-	for_each_index(i, base, order) {
-		assert(radix_tree_tag_get(&tree, i, 0));
-		assert(!radix_tree_tag_get(&tree, i, 1));
-	}
-
-	assert(tag_tagged_items(&tree, NULL, 0, ~0UL, 10, 0, 1) == 1);
-	assert(radix_tree_tag_clear(&tree, index, 0));
-
-	for_each_index(i, base, order) {
-		assert(!radix_tree_tag_get(&tree, i, 0));
-		assert(radix_tree_tag_get(&tree, i, 1));
-	}
-
-	assert(radix_tree_tag_clear(&tree, index, 1));
-
-	assert(!radix_tree_tagged(&tree, 0));
-	assert(!radix_tree_tagged(&tree, 1));
-
-	item_kill_tree(&tree);
-}
-
-static void __multiorder_tag_test2(unsigned order, unsigned long index2)
+static int item_insert_order(struct xarray *xa, unsigned long index,
+			unsigned order)
 {
-	RADIX_TREE(tree, GFP_KERNEL);
-	unsigned long index = (1 << order);
-	index2 += index;
-
-	assert(item_insert_order(&tree, 0, order) == 0);
-	assert(item_insert(&tree, index2) == 0);
-
-	assert(radix_tree_tag_set(&tree, 0, 0));
-	assert(radix_tree_tag_set(&tree, index2, 0));
-
-	assert(tag_tagged_items(&tree, NULL, 0, ~0UL, 10, 0, 1) == 2);
-
-	item_kill_tree(&tree);
-}
-
-static void multiorder_tag_tests(void)
-{
-	int i, j;
-
-	/* test multi-order entry for indices 0-7 with no sibling pointers */
-	__multiorder_tag_test(0, 3);
-	__multiorder_tag_test(5, 3);
-
-	/* test multi-order entry for indices 8-15 with no sibling pointers */
-	__multiorder_tag_test(8, 3);
-	__multiorder_tag_test(15, 3);
-
-	/*
-	 * Our order 5 entry covers indices 0-31 in a tree with height=2.
-	 * This is broken up as follows:
-	 * 0-7:		canonical entry
-	 * 8-15:	sibling 1
-	 * 16-23:	sibling 2
-	 * 24-31:	sibling 3
-	 */
-	__multiorder_tag_test(0, 5);
-	__multiorder_tag_test(29, 5);
-
-	/* same test, but with indices 32-63 */
-	__multiorder_tag_test(32, 5);
-	__multiorder_tag_test(44, 5);
-
-	/*
-	 * Our order 8 entry covers indices 0-255 in a tree with height=3.
-	 * This is broken up as follows:
-	 * 0-63:	canonical entry
-	 * 64-127:	sibling 1
-	 * 128-191:	sibling 2
-	 * 192-255:	sibling 3
-	 */
-	__multiorder_tag_test(0, 8);
-	__multiorder_tag_test(190, 8);
-
-	/* same test, but with indices 256-511 */
-	__multiorder_tag_test(256, 8);
-	__multiorder_tag_test(300, 8);
-
-	__multiorder_tag_test(0x12345678UL, 8);
-
-	for (i = 1; i < 10; i++)
-		for (j = 0; j < (10 << i); j++)
-			__multiorder_tag_test2(i, j);
-}
-
-static void multiorder_check(unsigned long index, int order)
-{
-	unsigned long i;
-	unsigned long min = index & ~((1UL << order) - 1);
-	unsigned long max = min + (1UL << order);
-	void **slot;
-	struct item *item2 = item_create(min, order);
-	RADIX_TREE(tree, GFP_KERNEL);
-
-	printv(2, "Multiorder index %ld, order %d\n", index, order);
-
-	assert(item_insert_order(&tree, index, order) == 0);
-
-	for (i = min; i < max; i++) {
-		struct item *item = item_lookup(&tree, i);
-		assert(item != 0);
-		assert(item->index == index);
-	}
-	for (i = 0; i < min; i++)
-		item_check_absent(&tree, i);
-	for (i = max; i < 2*max; i++)
-		item_check_absent(&tree, i);
-	for (i = min; i < max; i++)
-		assert(radix_tree_insert(&tree, i, item2) == -EEXIST);
-
-	slot = radix_tree_lookup_slot(&tree, index);
-	free(*slot);
-	radix_tree_replace_slot(&tree, slot, item2);
-	for (i = min; i < max; i++) {
-		struct item *item = item_lookup(&tree, i);
-		assert(item != 0);
-		assert(item->index == min);
-	}
-
-	assert(item_delete(&tree, min) != 0);
-
-	for (i = 0; i < 2*max; i++)
-		item_check_absent(&tree, i);
-}
-
-static void multiorder_shrink(unsigned long index, int order)
-{
-	unsigned long i;
-	unsigned long max = 1 << order;
-	RADIX_TREE(tree, GFP_KERNEL);
-	struct radix_tree_node *node;
-
-	printv(2, "Multiorder shrink index %ld, order %d\n", index, order);
+	XA_STATE_ORDER(xas, xa, index, order);
+	struct item *item = item_create(index, order);
 
-	assert(item_insert_order(&tree, 0, order) == 0);
-
-	node = tree.rnode;
-
-	assert(item_insert(&tree, index) == 0);
-	assert(node != tree.rnode);
-
-	assert(item_delete(&tree, index) != 0);
-	assert(node == tree.rnode);
-
-	for (i = 0; i < max; i++) {
-		struct item *item = item_lookup(&tree, i);
-		assert(item != 0);
-		assert(item->index == 0);
-	}
-	for (i = max; i < 2*max; i++)
-		item_check_absent(&tree, i);
-
-	if (!item_delete(&tree, 0)) {
-		printv(2, "failed to delete index %ld (order %d)\n", index, order);
-		abort();
-	}
-
-	for (i = 0; i < 2*max; i++)
-		item_check_absent(&tree, i);
-}
-
-static void multiorder_insert_bug(void)
-{
-	RADIX_TREE(tree, GFP_KERNEL);
+	do {
+		xas_lock(&xas);
+		xas_store(&xas, item);
+		xas_unlock(&xas);
+	} while (xas_nomem(&xas, GFP_KERNEL));
 
-	item_insert(&tree, 0);
-	radix_tree_tag_set(&tree, 0, 0);
-	item_insert_order(&tree, 3 << 6, 6);
+	if (!xas_error(&xas))
+		return 0;
 
-	item_kill_tree(&tree);
+	free(item);
+	return xas_error(&xas);
 }
 
-void multiorder_iteration(void)
+void multiorder_iteration(struct xarray *xa)
 {
-	RADIX_TREE(tree, GFP_KERNEL);
-	struct radix_tree_iter iter;
-	void **slot;
+	XA_STATE(xas, xa, 0);
+	struct item *item;
 	int i, j, err;
 
-	printv(1, "Multiorder iteration test\n");
-
 #define NUM_ENTRIES 11
 	int index[NUM_ENTRIES] = {0, 2, 4, 8, 16, 32, 34, 36, 64, 72, 128};
 	int order[NUM_ENTRIES] = {1, 1, 2, 3,  4,  1,  0,  1,  3,  0, 7};
 
+	printv(1, "Multiorder iteration test\n");
+
 	for (i = 0; i < NUM_ENTRIES; i++) {
-		err = item_insert_order(&tree, index[i], order[i]);
+		err = item_insert_order(xa, index[i], order[i]);
 		assert(!err);
 	}
 
@@ -252,14 +61,14 @@ void multiorder_iteration(void)
 			if (j <= (index[i] | ((1 << order[i]) - 1)))
 				break;
 
-		radix_tree_for_each_slot(slot, &tree, &iter, j) {
-			int height = order[i] / RADIX_TREE_MAP_SHIFT;
-			int shift = height * RADIX_TREE_MAP_SHIFT;
+		xas_set(&xas, j);
+		xas_for_each(&xas, item, ULONG_MAX) {
+			int height = order[i] / XA_CHUNK_SHIFT;
+			int shift = height * XA_CHUNK_SHIFT;
 			unsigned long mask = (1UL << order[i]) - 1;
-			struct item *item = *slot;
 
-			assert((iter.index | mask) == (index[i] | mask));
-			assert(iter.shift == shift);
+			assert((xas.xa_index | mask) == (index[i] | mask));
+			assert(xas.xa_node->shift == shift);
 			assert(!radix_tree_is_internal_node(item));
 			assert((item->index | mask) == (index[i] | mask));
 			assert(item->order == order[i]);
@@ -267,18 +76,15 @@ void multiorder_iteration(void)
 		}
 	}
 
-	item_kill_tree(&tree);
+	item_kill_tree(xa);
 }
 
-void multiorder_tagged_iteration(void)
+void multiorder_tagged_iteration(struct xarray *xa)
 {
-	RADIX_TREE(tree, GFP_KERNEL);
-	struct radix_tree_iter iter;
-	void **slot;
+	XA_STATE(xas, xa, 0);
+	struct item *item;
 	int i, j;
 
-	printv(1, "Multiorder tagged iteration test\n");
-
 #define MT_NUM_ENTRIES 9
 	int index[MT_NUM_ENTRIES] = {0, 2, 4, 16, 32, 40, 64, 72, 128};
 	int order[MT_NUM_ENTRIES] = {1, 0, 2, 4,  3,  1,  3,  0,   7};
@@ -286,13 +92,15 @@ void multiorder_tagged_iteration(void)
 #define TAG_ENTRIES 7
 	int tag_index[TAG_ENTRIES] = {0, 4, 16, 40, 64, 72, 128};
 
+	printv(1, "Multiorder tagged iteration test\n");
+
 	for (i = 0; i < MT_NUM_ENTRIES; i++)
-		assert(!item_insert_order(&tree, index[i], order[i]));
+		assert(!item_insert_order(xa, index[i], order[i]));
 
-	assert(!radix_tree_tagged(&tree, 1));
+	assert(!xa_marked(xa, XA_MARK_1));
 
 	for (i = 0; i < TAG_ENTRIES; i++)
-		assert(radix_tree_tag_set(&tree, tag_index[i], 1));
+		xa_set_mark(xa, tag_index[i], XA_MARK_1);
 
 	for (j = 0; j < 256; j++) {
 		int k;
@@ -304,23 +112,23 @@ void multiorder_tagged_iteration(void)
 				break;
 		}
 
-		radix_tree_for_each_tagged(slot, &tree, &iter, j, 1) {
+		xas_set(&xas, j);
+		xas_for_each_marked(&xas, item, ULONG_MAX, XA_MARK_1) {
 			unsigned long mask;
-			struct item *item = *slot;
 			for (k = i; index[k] < tag_index[i]; k++)
 				;
 			mask = (1UL << order[k]) - 1;
 
-			assert((iter.index | mask) == (tag_index[i] | mask));
-			assert(!radix_tree_is_internal_node(item));
+			assert((xas.xa_index | mask) == (tag_index[i] | mask));
+			assert(!xa_is_internal(item));
 			assert((item->index | mask) == (tag_index[i] | mask));
 			assert(item->order == order[k]);
 			i++;
 		}
 	}
 
-	assert(tag_tagged_items(&tree, NULL, 0, ~0UL, TAG_ENTRIES, 1, 2) ==
-				TAG_ENTRIES);
+	assert(tag_tagged_items(xa, 0, ULONG_MAX, TAG_ENTRIES, XA_MARK_1,
+				XA_MARK_2) == TAG_ENTRIES);
 
 	for (j = 0; j < 256; j++) {
 		int mask, k;
@@ -332,297 +140,31 @@ void multiorder_tagged_iteration(void)
 				break;
 		}
 
-		radix_tree_for_each_tagged(slot, &tree, &iter, j, 2) {
-			struct item *item = *slot;
+		xas_set(&xas, j);
+		xas_for_each_marked(&xas, item, ULONG_MAX, XA_MARK_2) {
 			for (k = i; index[k] < tag_index[i]; k++)
 				;
 			mask = (1 << order[k]) - 1;
 
-			assert((iter.index | mask) == (tag_index[i] | mask));
-			assert(!radix_tree_is_internal_node(item));
+			assert((xas.xa_index | mask) == (tag_index[i] | mask));
+			assert(!xa_is_internal(item));
 			assert((item->index | mask) == (tag_index[i] | mask));
 			assert(item->order == order[k]);
 			i++;
 		}
 	}
 
-	assert(tag_tagged_items(&tree, NULL, 1, ~0UL, MT_NUM_ENTRIES * 2, 1, 0)
-			== TAG_ENTRIES);
+	assert(tag_tagged_items(xa, 1, ULONG_MAX, MT_NUM_ENTRIES * 2, XA_MARK_1,
+				XA_MARK_0) == TAG_ENTRIES);
 	i = 0;
-	radix_tree_for_each_tagged(slot, &tree, &iter, 0, 0) {
-		assert(iter.index == tag_index[i]);
+	xas_set(&xas, 0);
+	xas_for_each_marked(&xas, item, ULONG_MAX, XA_MARK_0) {
+		assert(xas.xa_index == tag_index[i]);
 		i++;
 	}
+	assert(i == TAG_ENTRIES);
 
-	item_kill_tree(&tree);
-}
-
-/*
- * Basic join checks: make sure we can't find an entry in the tree after
- * a larger entry has replaced it
- */
-static void multiorder_join1(unsigned long index,
-				unsigned order1, unsigned order2)
-{
-	unsigned long loc;
-	void *item, *item2 = item_create(index + 1, order1);
-	RADIX_TREE(tree, GFP_KERNEL);
-
-	item_insert_order(&tree, index, order2);
-	item = radix_tree_lookup(&tree, index);
-	radix_tree_join(&tree, index + 1, order1, item2);
-	loc = find_item(&tree, item);
-	if (loc == -1)
-		free(item);
-	item = radix_tree_lookup(&tree, index + 1);
-	assert(item == item2);
-	item_kill_tree(&tree);
-}
-
-/*
- * Check that the accounting of exceptional entries is handled correctly
- * by joining an exceptional entry to a normal pointer.
- */
-static void multiorder_join2(unsigned order1, unsigned order2)
-{
-	RADIX_TREE(tree, GFP_KERNEL);
-	struct radix_tree_node *node;
-	void *item1 = item_create(0, order1);
-	void *item2;
-
-	item_insert_order(&tree, 0, order2);
-	radix_tree_insert(&tree, 1 << order2, (void *)0x12UL);
-	item2 = __radix_tree_lookup(&tree, 1 << order2, &node, NULL);
-	assert(item2 == (void *)0x12UL);
-	assert(node->exceptional == 1);
-
-	item2 = radix_tree_lookup(&tree, 0);
-	free(item2);
-
-	radix_tree_join(&tree, 0, order1, item1);
-	item2 = __radix_tree_lookup(&tree, 1 << order2, &node, NULL);
-	assert(item2 == item1);
-	assert(node->exceptional == 0);
-	item_kill_tree(&tree);
-}
-
-/*
- * This test revealed an accounting bug for exceptional entries at one point.
- * Nodes were being freed back into the pool with an elevated exception count
- * by radix_tree_join() and then radix_tree_split() was failing to zero the
- * count of exceptional entries.
- */
-static void multiorder_join3(unsigned int order)
-{
-	RADIX_TREE(tree, GFP_KERNEL);
-	struct radix_tree_node *node;
-	void **slot;
-	struct radix_tree_iter iter;
-	unsigned long i;
-
-	for (i = 0; i < (1 << order); i++) {
-		radix_tree_insert(&tree, i, (void *)0x12UL);
-	}
-
-	radix_tree_join(&tree, 0, order, (void *)0x16UL);
-	rcu_barrier();
-
-	radix_tree_split(&tree, 0, 0);
-
-	radix_tree_for_each_slot(slot, &tree, &iter, 0) {
-		radix_tree_iter_replace(&tree, &iter, slot, (void *)0x12UL);
-	}
-
-	__radix_tree_lookup(&tree, 0, &node, NULL);
-	assert(node->exceptional == node->count);
-
-	item_kill_tree(&tree);
-}
-
-static void multiorder_join(void)
-{
-	int i, j, idx;
-
-	for (idx = 0; idx < 1024; idx = idx * 2 + 3) {
-		for (i = 1; i < 15; i++) {
-			for (j = 0; j < i; j++) {
-				multiorder_join1(idx, i, j);
-			}
-		}
-	}
-
-	for (i = 1; i < 15; i++) {
-		for (j = 0; j < i; j++) {
-			multiorder_join2(i, j);
-		}
-	}
-
-	for (i = 3; i < 10; i++) {
-		multiorder_join3(i);
-	}
-}
-
-static void check_mem(unsigned old_order, unsigned new_order, unsigned alloc)
-{
-	struct radix_tree_preload *rtp = &radix_tree_preloads;
-	if (rtp->nr != 0)
-		printv(2, "split(%u %u) remaining %u\n", old_order, new_order,
-							rtp->nr);
-	/*
-	 * Can't check for equality here as some nodes may have been
-	 * RCU-freed while we ran.  But we should never finish with more
-	 * nodes allocated since they should have all been preloaded.
-	 */
-	if (nr_allocated > alloc)
-		printv(2, "split(%u %u) allocated %u %u\n", old_order, new_order,
-							alloc, nr_allocated);
-}
-
-static void __multiorder_split(int old_order, int new_order)
-{
-	RADIX_TREE(tree, GFP_ATOMIC);
-	void **slot;
-	struct radix_tree_iter iter;
-	unsigned alloc;
-	struct item *item;
-
-	radix_tree_preload(GFP_KERNEL);
-	assert(item_insert_order(&tree, 0, old_order) == 0);
-	radix_tree_preload_end();
-
-	/* Wipe out the preloaded cache or it'll confuse check_mem() */
-	radix_tree_cpu_dead(0);
-
-	item = radix_tree_tag_set(&tree, 0, 2);
-
-	radix_tree_split_preload(old_order, new_order, GFP_KERNEL);
-	alloc = nr_allocated;
-	radix_tree_split(&tree, 0, new_order);
-	check_mem(old_order, new_order, alloc);
-	radix_tree_for_each_slot(slot, &tree, &iter, 0) {
-		radix_tree_iter_replace(&tree, &iter, slot,
-					item_create(iter.index, new_order));
-	}
-	radix_tree_preload_end();
-
-	item_kill_tree(&tree);
-	free(item);
-}
-
-static void __multiorder_split2(int old_order, int new_order)
-{
-	RADIX_TREE(tree, GFP_KERNEL);
-	void **slot;
-	struct radix_tree_iter iter;
-	struct radix_tree_node *node;
-	void *item;
-
-	__radix_tree_insert(&tree, 0, old_order, (void *)0x12);
-
-	item = __radix_tree_lookup(&tree, 0, &node, NULL);
-	assert(item == (void *)0x12);
-	assert(node->exceptional > 0);
-
-	radix_tree_split(&tree, 0, new_order);
-	radix_tree_for_each_slot(slot, &tree, &iter, 0) {
-		radix_tree_iter_replace(&tree, &iter, slot,
-					item_create(iter.index, new_order));
-	}
-
-	item = __radix_tree_lookup(&tree, 0, &node, NULL);
-	assert(item != (void *)0x12);
-	assert(node->exceptional == 0);
-
-	item_kill_tree(&tree);
-}
-
-static void __multiorder_split3(int old_order, int new_order)
-{
-	RADIX_TREE(tree, GFP_KERNEL);
-	void **slot;
-	struct radix_tree_iter iter;
-	struct radix_tree_node *node;
-	void *item;
-
-	__radix_tree_insert(&tree, 0, old_order, (void *)0x12);
-
-	item = __radix_tree_lookup(&tree, 0, &node, NULL);
-	assert(item == (void *)0x12);
-	assert(node->exceptional > 0);
-
-	radix_tree_split(&tree, 0, new_order);
-	radix_tree_for_each_slot(slot, &tree, &iter, 0) {
-		radix_tree_iter_replace(&tree, &iter, slot, (void *)0x16);
-	}
-
-	item = __radix_tree_lookup(&tree, 0, &node, NULL);
-	assert(item == (void *)0x16);
-	assert(node->exceptional > 0);
-
-	item_kill_tree(&tree);
-
-	__radix_tree_insert(&tree, 0, old_order, (void *)0x12);
-
-	item = __radix_tree_lookup(&tree, 0, &node, NULL);
-	assert(item == (void *)0x12);
-	assert(node->exceptional > 0);
-
-	radix_tree_split(&tree, 0, new_order);
-	radix_tree_for_each_slot(slot, &tree, &iter, 0) {
-		if (iter.index == (1 << new_order))
-			radix_tree_iter_replace(&tree, &iter, slot,
-						(void *)0x16);
-		else
-			radix_tree_iter_replace(&tree, &iter, slot, NULL);
-	}
-
-	item = __radix_tree_lookup(&tree, 1 << new_order, &node, NULL);
-	assert(item == (void *)0x16);
-	assert(node->count == node->exceptional);
-	do {
-		node = node->parent;
-		if (!node)
-			break;
-		assert(node->count == 1);
-		assert(node->exceptional == 0);
-	} while (1);
-
-	item_kill_tree(&tree);
-}
-
-static void multiorder_split(void)
-{
-	int i, j;
-
-	for (i = 3; i < 11; i++)
-		for (j = 0; j < i; j++) {
-			__multiorder_split(i, j);
-			__multiorder_split2(i, j);
-			__multiorder_split3(i, j);
-		}
-}
-
-static void multiorder_account(void)
-{
-	RADIX_TREE(tree, GFP_KERNEL);
-	struct radix_tree_node *node;
-	void **slot;
-
-	item_insert_order(&tree, 0, 5);
-
-	__radix_tree_insert(&tree, 1 << 5, 5, (void *)0x12);
-	__radix_tree_lookup(&tree, 0, &node, NULL);
-	assert(node->count == node->exceptional * 2);
-	radix_tree_delete(&tree, 1 << 5);
-	assert(node->exceptional == 0);
-
-	__radix_tree_insert(&tree, 1 << 5, 5, (void *)0x12);
-	__radix_tree_lookup(&tree, 1 << 5, &node, &slot);
-	assert(node->count == node->exceptional * 2);
-	__radix_tree_replace(&tree, node, slot, NULL, NULL);
-	assert(node->exceptional == 0);
-
-	item_kill_tree(&tree);
+	item_kill_tree(xa);
 }
 
 bool stop_iteration = false;
@@ -645,68 +187,45 @@ static void *creator_func(void *ptr)
 
 static void *iterator_func(void *ptr)
 {
-	struct radix_tree_root *tree = ptr;
-	struct radix_tree_iter iter;
+	XA_STATE(xas, ptr, 0);
 	struct item *item;
-	void **slot;
 
 	while (!stop_iteration) {
 		rcu_read_lock();
-		radix_tree_for_each_slot(slot, tree, &iter, 0) {
-			item = radix_tree_deref_slot(slot);
-
-			if (!item)
+		xas_for_each(&xas, item, ULONG_MAX) {
+			if (xas_retry(&xas, item))
 				continue;
-			if (radix_tree_deref_retry(item)) {
-				slot = radix_tree_iter_retry(&iter);
-				continue;
-			}
 
-			item_sanity(item, iter.index);
+			item_sanity(item, xas.xa_index);
 		}
 		rcu_read_unlock();
 	}
 	return NULL;
 }
 
-static void multiorder_iteration_race(void)
+static void multiorder_iteration_race(struct xarray *xa)
 {
 	const int num_threads = sysconf(_SC_NPROCESSORS_ONLN);
 	pthread_t worker_thread[num_threads];
-	RADIX_TREE(tree, GFP_KERNEL);
 	int i;
 
-	pthread_create(&worker_thread[0], NULL, &creator_func, &tree);
+	pthread_create(&worker_thread[0], NULL, &creator_func, xa);
 	for (i = 1; i < num_threads; i++)
-		pthread_create(&worker_thread[i], NULL, &iterator_func, &tree);
+		pthread_create(&worker_thread[i], NULL, &iterator_func, xa);
 
 	for (i = 0; i < num_threads; i++)
 		pthread_join(worker_thread[i], NULL);
 
-	item_kill_tree(&tree);
+	item_kill_tree(xa);
 }
 
+static DEFINE_XARRAY(array);
+
 void multiorder_checks(void)
 {
-	int i;
-
-	for (i = 0; i < 20; i++) {
-		multiorder_check(200, i);
-		multiorder_check(0, i);
-		multiorder_check((1UL << i) + 1, i);
-	}
-
-	for (i = 0; i < 15; i++)
-		multiorder_shrink((1UL << (i + RADIX_TREE_MAP_SHIFT)), i);
-
-	multiorder_insert_bug();
-	multiorder_tag_tests();
-	multiorder_iteration();
-	multiorder_tagged_iteration();
-	multiorder_join();
-	multiorder_split();
-	multiorder_account();
-	multiorder_iteration_race();
+	multiorder_iteration(&array);
+	multiorder_tagged_iteration(&array);
+	multiorder_iteration_race(&array);
 
 	radix_tree_cpu_dead(0);
 }