Commit 6a559523 authored Oct 18, 2017 by Christoph Hellwig Committed by Greg Kroah-Hartman Dec 20, 2017

nvme: use kref_get_unless_zero in nvme_find_get_ns




[ Upstream commit 2dd4122854f697afc777582d18548dded03ce5dd ]

For kref_get_unless_zero to protect against lookup vs free races we need
to use it in all places where we aren't guaranteed to already hold a
reference.  There is no such guarantee in nvme_find_get_ns, so switch to
kref_get_unless_zero in this function.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent e2fce5a5

drivers/nvme/host/core.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -1619,7 +1619,8 @@ static struct nvme_ns nvme_find_get_ns(struct nvme_ctrl ctrl, unsigned nsid)
		mutex_lock(&ctrl->namespaces_mutex);
		list_for_each_entry(ns, &ctrl->namespaces, list) {
		if (ns->ns_id == nsid) {
		kref_get(&ns->kref);
		if (!kref_get_unless_zero(&ns->kref))
		continue;
		ret = ns;
		break;
		}