Ahh, I incorporated non-multipath disks into the mix and observing some
trouble. Details below:
On Thu, Nov 09, 2017 at 06:44:47PM +0100, Christoph Hellwig wrote:
> +#ifdef CONFIG_NVME_MULTIPATH
> + if (ns->head->disk) {
> + sprintf(disk_name, "nvme%dc%dn%d", ctrl->subsys->instance,
> + ctrl->cntlid, ns->head->instance);
> + flags = GENHD_FL_HIDDEN;
> + } else
> +#endif
> + sprintf(disk_name, "nvme%dn%d", ctrl->instance, ns->head->instance);
...
> +int nvme_mpath_alloc_disk(struct nvme_ctrl *ctrl, struct nvme_ns_head *head)
> +{
> + struct request_queue *q;
> + bool vwc = false;
> +
> + bio_list_init(&head->requeue_list);
> + spin_lock_init(&head->requeue_lock);
> + INIT_WORK(&head->requeue_work, nvme_requeue_work);
> +
> + /*
> + * Add a multipath node if the subsystems supports multiple controllers.
> + * We also do this for private namespaces as the namespace sharing data could
> + * change after a rescan.
> + */
> + if (!(ctrl->subsys->cmic & (1 << 1)) || !multipath)
> + return 0;
...
> + sprintf(head->disk->disk_name, "nvme%dn%d",
> + ctrl->subsys->instance, head->instance);
If we've CMIC capabilities, we'll use the subsys->instance; if we don't
have CMIC, we use the ctrl->instance.
Since the two instances are independent of each other, they can create
duplicate names.
To fix, I think we'll need to always use the subsys instance for
consistency if CONFIG_NVME_MULTIPATH=y.
---
@@ -2837,8 +2826,10 @@ static void nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid)
ctrl->cntlid, ns->head->instance);
flags = GENHD_FL_HIDDEN;
} else
+ sprintf(disk_name, "nvme%dn%d", ctrl->subsys->instance, ns->head->instance);
+#else
+ sprintf(disk_name, "nvme%dn%d", ctrl->instance, ns->head->instance);
#endif
- sprintf(disk_name, "nvme%dn%d", ctrl->instance, ns->head->instance);
if ((ctrl->quirks & NVME_QUIRK_LIGHTNVM) && id->vs[0] == 0x1) {
if (nvme_nvm_register(ns, disk_name, node)) {
--
This may confuse some people since the block device's name will not always
match up to the controller's chardev name, but I don't see another way
to do it.
