Commit 3012110d authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle)
Browse files

XArray: Fix splitting to non-zero orders 



Splitting an order-4 entry into order-2 entries would leave the array
containing pointers to 000040008000c000 instead of 000044448888cccc.
This is a one-character fix, but enhance the test suite to check this
case.

Reported-by: default avatarZi Yan <ziy@nvidia.com>
Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
parent 12efebab

lib/test_xarray.c

+14 −12
Original line number Diff line number Diff line
@@ -1530,24 +1530,24 @@ static noinline void check_store_range(struct xarray *xa) 


#ifdef CONFIG_XARRAY_MULTI

static void check_split_1(struct xarray *xa, unsigned long index,

							unsigned int order)

				unsigned int order, unsigned int new_order)

{

	XA_STATE(xas, xa, index);

	void *entry;

	unsigned int i = 0;

	XA_STATE_ORDER(xas, xa, index, new_order);

	unsigned int i;



	xa_store_order(xa, index, order, xa, GFP_KERNEL);



	xas_split_alloc(&xas, xa, order, GFP_KERNEL);

	xas_lock(&xas);

	xas_split(&xas, xa, order);

	for (i = 0; i < (1 << order); i += (1 << new_order))

		__xa_store(xa, index + i, xa_mk_index(index + i), 0);

	xas_unlock(&xas);



	xa_for_each(xa, index, entry) {

		XA_BUG_ON(xa, entry != xa);

		i++;

	for (i = 0; i < (1 << order); i++) {

		unsigned int val = index + (i & ~((1 << new_order) - 1));

		XA_BUG_ON(xa, xa_load(xa, index + i) != xa_mk_index(val));

	}

	XA_BUG_ON(xa, i != 1 << order);



	xa_set_mark(xa, index, XA_MARK_0);

	XA_BUG_ON(xa, !xa_get_mark(xa, index, XA_MARK_0));
@@ -1557,14 +1557,16 @@ static void check_split_1(struct xarray *xa, unsigned long index, 


static noinline void check_split(struct xarray *xa)

{

	unsigned int order;

	unsigned int order, new_order;



	XA_BUG_ON(xa, !xa_empty(xa));



	for (order = 1; order < 2 * XA_CHUNK_SHIFT; order++) {

		check_split_1(xa, 0, order);

		check_split_1(xa, 1UL << order, order);

		check_split_1(xa, 3UL << order, order);

		for (new_order = 0; new_order < order; new_order++) {

			check_split_1(xa, 0, order, new_order);

			check_split_1(xa, 1UL << order, order, new_order);

			check_split_1(xa, 3UL << order, order, new_order);

		}

	}

}

#else

lib/xarray.c

+2 −2
Original line number Diff line number Diff line
@@ -1011,7 +1011,7 @@ void xas_split_alloc(struct xa_state *xas, void *entry, unsigned int order, 


	do {

		unsigned int i;

		void *sibling;

		void *sibling = NULL;

		struct xa_node *node;



		node = kmem_cache_alloc(radix_tree_node_cachep, gfp);
@@ -1021,7 +1021,7 @@ void xas_split_alloc(struct xa_state *xas, void *entry, unsigned int order, 
		for (i = 0; i < XA_CHUNK_SIZE; i++) {

			if ((i & mask) == 0) {

				RCU_INIT_POINTER(node->slots[i], entry);

				sibling = xa_mk_sibling(0);

				sibling = xa_mk_sibling(i);

			} else {

				RCU_INIT_POINTER(node->slots[i], sibling);

			}