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authorMatthew Wilcox (Oracle) <willy@infradead.org>2020-11-19 08:32:31 -0500
committerMatthew Wilcox (Oracle) <willy@infradead.org>2021-03-30 13:42:33 -0400
commit3012110d71f41410932924e1d188f9eb57f1f824 (patch)
treebdad57981759c2fe3fc329cef4577297ab9a76b8
parent12efebab09e383bf366bec323bd296b7d90e1c43 (diff)
downloadvfs-3012110d71f41410932924e1d188f9eb57f1f824.tar.gz
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: Zi Yan <ziy@nvidia.com> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
-rw-r--r--lib/test_xarray.c26
-rw-r--r--lib/xarray.c4
2 files changed, 16 insertions, 14 deletions
diff --git a/lib/test_xarray.c b/lib/test_xarray.c
index 8294f43f498164..8b1c318189ce80 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 fb3a0ccebb7e8c..f5d8f54907b4f8 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);
}