From: Matthew Wilcox (Oracle) willy@infradead.org
[ Upstream commit 3012110d71f41410932924e1d188f9eb57f1f824 ]
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: Zi Yan ziy@nvidia.com Signed-off-by: Matthew Wilcox (Oracle) willy@infradead.org Signed-off-by: Sasha Levin sashal@kernel.org --- lib/test_xarray.c | 26 ++++++++++++++------------ lib/xarray.c | 4 ++-- 2 files changed, 16 insertions(+), 14 deletions(-)
diff --git a/lib/test_xarray.c b/lib/test_xarray.c index 8294f43f4981..8b1c318189ce 100644 --- a/lib/test_xarray.c +++ b/lib/test_xarray.c @@ -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 diff --git a/lib/xarray.c b/lib/xarray.c index 5fa51614802a..ed775dee1074 100644 --- a/lib/xarray.c +++ b/lib/xarray.c @@ -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); }