XArray: Fix xa_find_after with multi-index entries
If the entry is of an order which is a multiple of XA_CHUNK_SIZE,
the current detection of sibling entries does not work. Factor out
an xas_sibling() function to make xa_find_after() a little more
understandable, and write a new implementation that doesn't suffer from
the same bug.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: stable@vger.kernel.org
diff --git a/lib/test_xarray.c b/lib/test_xarray.c
index 90584c6..c8cc97d 100644
--- a/lib/test_xarray.c
+++ b/lib/test_xarray.c
@@ -902,28 +902,30 @@
XA_BUG_ON(xa, !xa_empty(xa));
}
-static noinline void check_multi_find(struct xarray *xa)
+static noinline void check_multi_find_1(struct xarray *xa, unsigned order)
{
#ifdef CONFIG_XARRAY_MULTI
+ unsigned long multi = 3 << order;
+ unsigned long next = 4 << order;
unsigned long index;
- xa_store_order(xa, 12, 2, xa_mk_value(12), GFP_KERNEL);
- XA_BUG_ON(xa, xa_store_index(xa, 16, GFP_KERNEL) != NULL);
+ xa_store_order(xa, multi, order, xa_mk_value(multi), GFP_KERNEL);
+ XA_BUG_ON(xa, xa_store_index(xa, next, GFP_KERNEL) != NULL);
index = 0;
XA_BUG_ON(xa, xa_find(xa, &index, ULONG_MAX, XA_PRESENT) !=
- xa_mk_value(12));
- XA_BUG_ON(xa, index != 12);
- index = 13;
+ xa_mk_value(multi));
+ XA_BUG_ON(xa, index != multi);
+ index = multi + 1;
XA_BUG_ON(xa, xa_find(xa, &index, ULONG_MAX, XA_PRESENT) !=
- xa_mk_value(12));
- XA_BUG_ON(xa, (index < 12) || (index >= 16));
+ xa_mk_value(multi));
+ XA_BUG_ON(xa, (index < multi) || (index >= next));
XA_BUG_ON(xa, xa_find_after(xa, &index, ULONG_MAX, XA_PRESENT) !=
- xa_mk_value(16));
- XA_BUG_ON(xa, index != 16);
+ xa_mk_value(next));
+ XA_BUG_ON(xa, index != next);
- xa_erase_index(xa, 12);
- xa_erase_index(xa, 16);
+ xa_erase_index(xa, multi);
+ xa_erase_index(xa, next);
XA_BUG_ON(xa, !xa_empty(xa));
#endif
}
@@ -1064,11 +1066,15 @@
static noinline void check_find(struct xarray *xa)
{
+ unsigned i;
+
check_find_1(xa);
check_find_2(xa);
check_find_3(xa);
check_find_4(xa);
- check_multi_find(xa);
+
+ for (i = 2; i < 10; i++)
+ check_multi_find_1(xa, i);
check_multi_find_2(xa);
}