On Fri, Aug 27, 2021 at 12:18:02PM -0700, Luis Chamberlain wrote: > @@ -479,13 +479,17 @@ int nvme_mpath_alloc_disk(struct nvme_ctrl *ctrl, struct nvme_ns_head *head) > static void nvme_mpath_set_live(struct nvme_ns *ns) > { > struct nvme_ns_head *head = ns->head; > + int rc; > > if (!head->disk) > return; > > - if (!test_and_set_bit(NVME_NSHEAD_DISK_LIVE, &head->flags)) { > - device_add_disk(&head->subsys->dev, head->disk, > - nvme_ns_id_attr_groups); > + if (!test_bit(NVME_NSHEAD_DISK_LIVE, &head->flags)) { This should still be test_and_set_bit() because it is protecting against two nvme paths simultaneously calling device_add_disk() on the same namespace head. > + rc = device_add_disk(&head->subsys->dev, head->disk, > + nvme_ns_id_attr_groups); > + if (rc) > + return; > + set_bit(NVME_NSHEAD_DISK_LIVE, &head->flags); > nvme_add_ns_head_cdev(head); > }