xarray: Add XArray iterators
The xa_for_each iterator allows the user to efficiently walk a range
of the array, executing the loop body once for each entry in that
range that matches the filter. This commit also includes xa_find()
and xa_find_after() which are helper functions for xa_for_each() but
may also be useful in their own right.
In the xas family of functions, we have xas_for_each(), xas_find(),
xas_next_entry(), xas_for_each_tagged(), xas_find_tagged(),
xas_next_tagged() and xas_pause().
Signed-off-by: Matthew Wilcox <willy@infradead.org>
diff --git a/lib/test_xarray.c b/lib/test_xarray.c
index fb47225..e3c2d4d 100644
--- a/lib/test_xarray.c
+++ b/lib/test_xarray.c
@@ -75,6 +75,48 @@
// XA_BUG_ON(xa, xa_err(xa_store(xa, 0, xa_mk_internal(0), 0)) != -EINVAL);
}
+static noinline void check_xas_retry(struct xarray *xa)
+{
+ XA_STATE(xas, xa, 0);
+ void *entry;
+
+ xa_store_index(xa, 0, GFP_KERNEL);
+ xa_store_index(xa, 1, GFP_KERNEL);
+
+ rcu_read_lock();
+ XA_BUG_ON(xa, xas_find(&xas, ULONG_MAX) != xa_mk_value(0));
+ xa_erase_index(xa, 1);
+ XA_BUG_ON(xa, !xa_is_retry(xas_reload(&xas)));
+ XA_BUG_ON(xa, xas_retry(&xas, NULL));
+ XA_BUG_ON(xa, xas_retry(&xas, xa_mk_value(0)));
+ xas_reset(&xas);
+ XA_BUG_ON(xa, xas.xa_node != XAS_RESTART);
+ XA_BUG_ON(xa, xas_next_entry(&xas, ULONG_MAX) != xa_mk_value(0));
+ XA_BUG_ON(xa, xas.xa_node != NULL);
+
+ XA_BUG_ON(xa, xa_store_index(xa, 1, GFP_KERNEL) != NULL);
+ XA_BUG_ON(xa, !xa_is_internal(xas_reload(&xas)));
+ xas.xa_node = XAS_RESTART;
+ XA_BUG_ON(xa, xas_next_entry(&xas, ULONG_MAX) != xa_mk_value(0));
+ rcu_read_unlock();
+
+ /* Make sure we can iterate through retry entries */
+ xas_lock(&xas);
+ xas_set(&xas, 0);
+ xas_store(&xas, XA_RETRY_ENTRY);
+ xas_set(&xas, 1);
+ xas_store(&xas, XA_RETRY_ENTRY);
+
+ xas_set(&xas, 0);
+ xas_for_each(&xas, entry, ULONG_MAX) {
+ xas_store(&xas, xa_mk_value(xas.xa_index));
+ }
+ xas_unlock(&xas);
+
+ xa_erase_index(xa, 0);
+ xa_erase_index(xa, 1);
+}
+
static noinline void check_xa_load(struct xarray *xa)
{
unsigned long i, j;
@@ -217,6 +259,44 @@
XA_BUG_ON(xa, !xa_empty(xa));
}
+static noinline void check_xas_erase(struct xarray *xa)
+{
+ XA_STATE(xas, xa, 0);
+ void *entry;
+ unsigned long i, j;
+
+ for (i = 0; i < 200; i++) {
+ for (j = i; j < 2 * i + 17; j++) {
+ xas_set(&xas, j);
+ do {
+ xas_lock(&xas);
+ xas_store(&xas, xa_mk_value(j));
+ xas_unlock(&xas);
+ } while (xas_nomem(&xas, GFP_KERNEL));
+ }
+
+ xas_set(&xas, ULONG_MAX);
+ do {
+ xas_lock(&xas);
+ xas_store(&xas, xa_mk_value(0));
+ xas_unlock(&xas);
+ } while (xas_nomem(&xas, GFP_KERNEL));
+
+ xas_lock(&xas);
+ xas_store(&xas, NULL);
+
+ xas_set(&xas, 0);
+ j = i;
+ xas_for_each(&xas, entry, ULONG_MAX) {
+ XA_BUG_ON(xa, entry != xa_mk_value(j));
+ xas_store(&xas, NULL);
+ j++;
+ }
+ xas_unlock(&xas);
+ XA_BUG_ON(xa, !xa_empty(xa));
+ }
+}
+
static noinline void check_multi_store(struct xarray *xa)
{
#ifdef CONFIG_XARRAY_MULTI
@@ -285,16 +365,119 @@
#endif
}
+static noinline void check_multi_find(struct xarray *xa)
+{
+#ifdef CONFIG_XARRAY_MULTI
+ 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);
+
+ 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_BUG_ON(xa, xa_find(xa, &index, ULONG_MAX, XA_PRESENT) !=
+ xa_mk_value(12));
+ XA_BUG_ON(xa, (index < 12) || (index >= 16));
+ XA_BUG_ON(xa, xa_find_after(xa, &index, ULONG_MAX, XA_PRESENT) !=
+ xa_mk_value(16));
+ XA_BUG_ON(xa, index != 16);
+
+ xa_erase_index(xa, 12);
+ xa_erase_index(xa, 16);
+ XA_BUG_ON(xa, !xa_empty(xa));
+#endif
+}
+
+static noinline void check_multi_find_2(struct xarray *xa)
+{
+ unsigned int max_order = IS_ENABLED(CONFIG_XARRAY_MULTI) ? 10 : 1;
+ unsigned int i, j;
+ void *entry;
+
+ for (i = 0; i < max_order; i++) {
+ unsigned long index = 1UL << i;
+ for (j = 0; j < index; j++) {
+ XA_STATE(xas, xa, j + index);
+ xa_store_index(xa, index - 1, GFP_KERNEL);
+ xa_store_order(xa, index, i, xa_mk_value(index),
+ GFP_KERNEL);
+ rcu_read_lock();
+ xas_for_each(&xas, entry, ULONG_MAX) {
+ xa_erase_index(xa, index);
+ }
+ rcu_read_unlock();
+ xa_erase_index(xa, index - 1);
+ XA_BUG_ON(xa, !xa_empty(xa));
+ }
+ }
+}
+
+static noinline void check_find(struct xarray *xa)
+{
+ unsigned long i, j, k;
+
+ XA_BUG_ON(xa, !xa_empty(xa));
+
+ /*
+ * Check xa_find with all pairs between 0 and 99 inclusive,
+ * starting at every index between 0 and 99
+ */
+ for (i = 0; i < 100; i++) {
+ XA_BUG_ON(xa, xa_store_index(xa, i, GFP_KERNEL) != NULL);
+ xa_set_mark(xa, i, XA_MARK_0);
+ for (j = 0; j < i; j++) {
+ XA_BUG_ON(xa, xa_store_index(xa, j, GFP_KERNEL) !=
+ NULL);
+ xa_set_mark(xa, j, XA_MARK_0);
+ for (k = 0; k < 100; k++) {
+ unsigned long index = k;
+ void *entry = xa_find(xa, &index, ULONG_MAX,
+ XA_PRESENT);
+ if (k <= j)
+ XA_BUG_ON(xa, index != j);
+ else if (k <= i)
+ XA_BUG_ON(xa, index != i);
+ else
+ XA_BUG_ON(xa, entry != NULL);
+
+ index = k;
+ entry = xa_find(xa, &index, ULONG_MAX,
+ XA_MARK_0);
+ if (k <= j)
+ XA_BUG_ON(xa, index != j);
+ else if (k <= i)
+ XA_BUG_ON(xa, index != i);
+ else
+ XA_BUG_ON(xa, entry != NULL);
+ }
+ xa_erase_index(xa, j);
+ XA_BUG_ON(xa, xa_get_mark(xa, j, XA_MARK_0));
+ XA_BUG_ON(xa, !xa_get_mark(xa, i, XA_MARK_0));
+ }
+ xa_erase_index(xa, i);
+ XA_BUG_ON(xa, xa_get_mark(xa, i, XA_MARK_0));
+ }
+ XA_BUG_ON(xa, !xa_empty(xa));
+ check_multi_find(xa);
+ check_multi_find_2(xa);
+}
+
static DEFINE_XARRAY(array);
static int xarray_checks(void)
{
check_xa_err(&array);
+ check_xas_retry(&array);
check_xa_load(&array);
check_xa_mark(&array);
check_xa_shrink(&array);
+ check_xas_erase(&array);
check_cmpxchg(&array);
check_multi_store(&array);
+ check_find(&array);
printk("XArray: %u of %u tests passed\n", tests_passed, tests_run);
return (tests_run == tests_passed) ? 0 : -EINVAL;