ida: Lock the IDA in ida_destroy
The user has no need to handle locking between ida_simple_get() and
ida_simple_remove(). They shouldn't be forced to think about whether
ida_destroy() might be called at the same time as any of their other
IDA manipulation calls. Improve the documnetation while I'm in here.
Signed-off-by: Matthew Wilcox <willy@infradead.org>
diff --git a/lib/idr.c b/lib/idr.c
index ed9c169..352c616 100644
--- a/lib/idr.c
+++ b/lib/idr.c
@@ -523,25 +523,30 @@ void ida_remove(struct ida *ida, int id)
EXPORT_SYMBOL(ida_remove);
/**
- * ida_destroy - Free the contents of an ida
- * @ida: ida handle
+ * ida_destroy() - Free all IDs.
+ * @ida: IDA handle.
*
- * Calling this function releases all resources associated with an IDA. When
- * this call returns, the IDA is empty and can be reused or freed. The caller
- * should not allow ida_remove() or ida_get_new_above() to be called at the
- * same time.
+ * Calling this function frees all IDs and releases all resources used
+ * by an IDA. When this call returns, the IDA is empty and can be reused
+ * or freed. If the IDA is already empty, there is no need to call this
+ * function.
+ *
+ * Context: Any context.
*/
void ida_destroy(struct ida *ida)
{
+ unsigned long flags;
struct radix_tree_iter iter;
void __rcu **slot;
+ xa_lock_irqsave(&ida->ida_rt, flags);
radix_tree_for_each_slot(slot, &ida->ida_rt, &iter, 0) {
struct ida_bitmap *bitmap = rcu_dereference_raw(*slot);
if (!radix_tree_exception(bitmap))
kfree(bitmap);
radix_tree_iter_delete(&ida->ida_rt, &iter, slot);
}
+ xa_unlock_irqrestore(&ida->ida_rt, flags);
}
EXPORT_SYMBOL(ida_destroy);