nvme: retrigger ANA log update if group descriptor isn't found

If ANA is enabled but no ANA group descriptor is found when creating
a new namespace the ANA log is most likely out of date, so trigger
a re-read. The namespace will be tagged with the NS_ANA_PENDING flag
to exclude it from path selection until the ANA log has been re-read.

Fixes: 32acab31 ("nvme: implement multipath access to nvme subsystems")
Reported-by: Martin George <marting@netapp.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/nvme/host/multipath.c

@@ -668,6 +668,10 @@ void nvme_mpath_add_disk(struct nvme_ns *ns, struct nvme_id_ns *id)
 		if (desc.state) {
 			/* found the group desc: update */
 			nvme_update_ns_ana_state(&desc, ns);
+		} else {
+			/* group desc not found: trigger a re-read */
+			set_bit(NVME_NS_ANA_PENDING, &ns->flags);
+			queue_work(nvme_wq, &ns->ctrl->ana_work);
 		}
 	} else {
 		ns->ana_state = NVME_ANA_OPTIMIZED;