From 50d97d50715a8664f6bddc18211279cd74b8c3bf Mon Sep 17 00:00:00 2001 From: Matthew Wilcox Date: Thu, 21 Jun 2018 15:36:45 -0400 Subject: 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 --- lib/idr.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) (limited to 'lib') diff --git a/lib/idr.c b/lib/idr.c index ed9c169c12bd..352c6160e2e0 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 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); -- cgit v1.2.3-59-g8ed1b