Commit 4ac76436 authored Jan 11, 2020 by Amol Grover Committed by Keith Busch Feb 04, 2020

nvmet: Pass lockdep expression to RCU lists



ctrl->subsys->namespaces and subsys->namespaces are traversed with
list_for_each_entry_rcu outside an RCU read-side critical section but
under the protection of ctrl->subsys->lock and subsys->lock respectively.

Hence, add the corresponding lockdep expression to the list traversal
primitive to silence false-positive lockdep warnings, and harden RCU
lists.

Reported-by: kbuild test robot <lkp@intel.com>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Amol Grover <frextrite@gmail.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>

parent c92bddee

drivers/nvme/target/core.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -555,7 +555,8 @@ int nvmet_ns_enable(struct nvmet_ns *ns)
		} else {
		struct nvmet_ns *old;

		list_for_each_entry_rcu(old, &subsys->namespaces, dev_link) {
		list_for_each_entry_rcu(old, &subsys->namespaces, dev_link,
		lockdep_is_held(&subsys->lock)) {
		BUG_ON(ns->nsid == old->nsid);
		if (ns->nsid < old->nsid)
		break;
		@@ -1172,7 +1173,8 @@ static void nvmet_setup_p2p_ns_map(struct nvmet_ctrl *ctrl,

		ctrl->p2p_client = get_device(req->p2p_client);

		list_for_each_entry_rcu(ns, &ctrl->subsys->namespaces, dev_link)
		list_for_each_entry_rcu(ns, &ctrl->subsys->namespaces, dev_link,
		lockdep_is_held(&ctrl->subsys->lock))
		nvmet_p2pmem_ns_add_p2p(ctrl, ns);
		}

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