[PATCH v3 1/3] nvme/multipath: fix failure to update ns ana state

[Anton Eidelman]

nvme_update_ana_state() has a deficiency that results
in failure to update the ana state for a namespace
in the following case:
nsid's in ctrl->namespaces: 1, 3, 4
nsid's in desc->nsids: 1, 2, 3, 4

Loop iteration 0:
    ns index = 0, n = 0, ns->head->ns_id = 1, nsid = 1, MATCH.
Loop iteration 1:
    ns index = 1, n = 1, ns->head->ns_id = 3, nsid = 2, NO MATCH.
Loop iteration 2:
    ns index = 2, n = 2, ns->head->ns_id = 4, nsid = 4, MATCH.

Result: missed nsid=3 and did not update its ana state.

Solution: when ns->head->ns_id is higher than nsid,
increment n and RETRY with the SAME ns.

Signed-off-by: Anton Eidelman <anton at lightbitslabs.com>
---
 drivers/nvme/host/multipath.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c
index 5d7bc58a27bd..e8ccdd398f78 100644
--- a/drivers/nvme/host/multipath.c
+++ b/drivers/nvme/host/multipath.c
@@ -600,14 +600,17 @@ static int nvme_update_ana_state(struct nvme_ctrl *ctrl,
 
 	down_read(&ctrl->namespaces_rwsem);
 	list_for_each_entry(ns, &ctrl->namespaces, list) {
-		unsigned nsid = le32_to_cpu(desc->nsids[n]);
-
+		unsigned nsid;
+again:
+		nsid = le32_to_cpu(desc->nsids[n]);
 		if (ns->head->ns_id < nsid)
 			continue;
 		if (ns->head->ns_id == nsid)
 			nvme_update_ns_ana_state(desc, ns);
 		if (++n == nr_nsids)
 			break;
+		if (ns->head->ns_id > nsid)
+			goto again;
 	}
 	up_read(&ctrl->namespaces_rwsem);
 	return 0;
-- 
2.25.1