xarray: Add xas_for_each_conflict

This iterator iterates over each entry that is stored in the index or
indices specified by the xa_state.  This is intended for use for a
conditional store of a multiindex entry, or to allow entries which are
about to be removed from the xarray to be disposed of properly.

Signed-off-by: Matthew Wilcox <willy@infradead.org>
This commit is contained in:
Matthew Wilcox
2018-06-01 22:46:02 -04:00
parent 64d3e9a9e0
commit 4e99d4e957
3 changed files with 146 additions and 0 deletions

View File

@@ -365,6 +365,73 @@ static noinline void check_multi_store(struct xarray *xa)
#endif
}
static noinline void __check_store_iter(struct xarray *xa, unsigned long start,
unsigned int order, unsigned int present)
{
XA_STATE_ORDER(xas, xa, start, order);
void *entry;
unsigned int count = 0;
retry:
xas_lock(&xas);
xas_for_each_conflict(&xas, entry) {
XA_BUG_ON(xa, !xa_is_value(entry));
XA_BUG_ON(xa, entry < xa_mk_value(start));
XA_BUG_ON(xa, entry > xa_mk_value(start + (1UL << order) - 1));
count++;
}
xas_store(&xas, xa_mk_value(start));
xas_unlock(&xas);
if (xas_nomem(&xas, GFP_KERNEL)) {
count = 0;
goto retry;
}
XA_BUG_ON(xa, xas_error(&xas));
XA_BUG_ON(xa, count != present);
XA_BUG_ON(xa, xa_load(xa, start) != xa_mk_value(start));
XA_BUG_ON(xa, xa_load(xa, start + (1UL << order) - 1) !=
xa_mk_value(start));
xa_erase_index(xa, start);
}
static noinline void check_store_iter(struct xarray *xa)
{
unsigned int i, j;
unsigned int max_order = IS_ENABLED(CONFIG_XARRAY_MULTI) ? 20 : 1;
for (i = 0; i < max_order; i++) {
unsigned int min = 1 << i;
unsigned int max = (2 << i) - 1;
__check_store_iter(xa, 0, i, 0);
XA_BUG_ON(xa, !xa_empty(xa));
__check_store_iter(xa, min, i, 0);
XA_BUG_ON(xa, !xa_empty(xa));
xa_store_index(xa, min, GFP_KERNEL);
__check_store_iter(xa, min, i, 1);
XA_BUG_ON(xa, !xa_empty(xa));
xa_store_index(xa, max, GFP_KERNEL);
__check_store_iter(xa, min, i, 1);
XA_BUG_ON(xa, !xa_empty(xa));
for (j = 0; j < min; j++)
xa_store_index(xa, j, GFP_KERNEL);
__check_store_iter(xa, 0, i, min);
XA_BUG_ON(xa, !xa_empty(xa));
for (j = 0; j < min; j++)
xa_store_index(xa, min + j, GFP_KERNEL);
__check_store_iter(xa, min, i, min);
XA_BUG_ON(xa, !xa_empty(xa));
}
#ifdef CONFIG_XARRAY_MULTI
xa_store_index(xa, 63, GFP_KERNEL);
xa_store_index(xa, 65, GFP_KERNEL);
__check_store_iter(xa, 64, 2, 1);
xa_erase_index(xa, 63);
#endif
XA_BUG_ON(xa, !xa_empty(xa));
}
static noinline void check_multi_find(struct xarray *xa)
{
#ifdef CONFIG_XARRAY_MULTI
@@ -627,6 +694,7 @@ static int xarray_checks(void)
check_find(&array);
check_destroy(&array);
check_move(&array);
check_store_iter(&array);
printk("XArray: %u of %u tests passed\n", tests_passed, tests_run);
return (tests_run == tests_passed) ? 0 : -EINVAL;