idr: Warn if old iterators see large IDs (72fd6c7b) · Commits · 戴 / test

Now that the IDR can be used to store large IDs, it is possible somebody might only partially convert their old code and use the iterators which can only handle IDs up to INT_MAX. It's probably unwise to show them a truncated ID, so settle for spewing warnings to dmesg, and terminating the iteration. Signed-off-by:

Matthew Wilcox <mawilcox@microsoft.com>

lib/idr.c

+8 −1

Original line number	Diff line number	Diff line
		@@ -159,7 +159,11 @@ int idr_for_each(const struct idr *idr,
		void __rcu **slot;

		radix_tree_for_each_slot(slot, &idr->idr_rt, &iter, 0) {
		int ret = fn(iter.index, rcu_dereference_raw(*slot), data);
		int ret;

		if (WARN_ON_ONCE(iter.index > INT_MAX))
		break;
		ret = fn(iter.index, rcu_dereference_raw(*slot), data);
		if (ret)
		return ret;
		}
		@@ -187,6 +191,9 @@ void idr_get_next(struct idr idr, int *nextid)
		if (!slot)
		return NULL;

		if (WARN_ON_ONCE(iter.index > INT_MAX))
		return NULL;

		*nextid = iter.index;
		return rcu_dereference_raw(*slot);
		}

Admin message