diff mbox

[08/17] nvme: use kref_get_unless_zero in nvme_find_get_ns

Message ID 20171018165258.23212-9-hch@lst.de (mailing list archive)
State New, archived
Headers show

Commit Message

Christoph Hellwig Oct. 18, 2017, 4:52 p.m. UTC 
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>
---
 drivers/nvme/host/core.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

Johannes Thumshirn Oct. 19, 2017, 6:54 a.m. UTC | #1 
Looks good,
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Sagi Grimberg Oct. 19, 2017, 6:59 a.m. UTC | #2 
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
diff mbox

Patch

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index bdae1e4fcd0b..3f51bd0326b5 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -2290,7 +2290,8 @@  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;
 		}