Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 50d97d50 authored by Matthew Wilcox's avatar Matthew Wilcox
Browse files

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: default avatarMatthew Wilcox <willy@infradead.org>
parent 76f070b4

lib/idr.c

+11 −6
Original line number Diff line number Diff line
@@ -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 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.

 *

 * 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.

 * 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);