[PATCH AUTOSEL 4.19 06/15] nvme-multipath: fix ANA state updates when a namespace is not present

[Sasha Levin]

From: Anton Eidelman <anton.eidelman@xxxxxxxxx>

[ Upstream commit 79f528afa93918519574773ea49a444c104bc1bd ]

nvme_update_ana_state() has a deficiency that results in a failure to
properly update the ana state for a namespace in the following case:

  NSIDs in ctrl->namespaces:	1, 3,    4
  NSIDs 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.

Where the update to the ANA state of NSID 3 is missed.  To fix this
increment n and retry the update with the same ns when ns->head->ns_id is
higher than nsid,

Signed-off-by: Anton Eidelman <anton@xxxxxxxxxxxxxxxxx>
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Sagi Grimberg <sagi@xxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 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 64f699a1afd7..022e03643dac 100644
--- a/drivers/nvme/host/multipath.c
+++ b/drivers/nvme/host/multipath.c
@@ -398,14 +398,17 @@ 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;
-- 
2.30.2