From: Anton Eidelman anton@lightbitslabs.com
[ Upstream commit e01f91dff91c7b16a6e3faf2565017d497a73f83 ]
ANA log parsing invokes nvme_update_ana_state() per ANA group desc. This updates the state of namespaces with nsids in desc->nsids[].
Both ctrl->namespaces list and desc->nsids[] array are sorted by nsid. Hence nvme_update_ana_state() performs a single walk over ctrl->namespaces: - if current namespace matches the current desc->nsids[n], this namespace is updated, and n is incremented. - the process stops when it encounters the end of either ctrl->namespaces end or desc->nsids[]
In case desc->nsids[n] does not match any of ctrl->namespaces, the remaining nsids following desc->nsids[n] will not be updated. Such situation was considered abnormal and generated WARN_ON_ONCE.
However ANA log MAY contain nsids not (yet) found in ctrl->namespaces. For example, lets consider the following scenario: - nvme0 exposes namespaces with nsids = [2, 3] to the host - a new namespace nsid = 1 is added dynamically - also, a ANA topology change is triggered - NS_CHANGED aen is generated and triggers scan_work - before scan_work discovers nsid=1 and creates a namespace, a NOTICE_ANA aen was issues and ana_work receives ANA log with nsids=[1, 2, 3]
Result: ana_work fails to update ANA state on existing namespaces [2, 3]
Solution: Change the way nvme_update_ana_state() namespace list walk checks the current namespace against desc->nsids[n] as follows: a) ns->head->ns_id < desc->nsids[n]: keep walking ctrl->namespaces. b) ns->head->ns_id == desc->nsids[n]: match, update the namespace c) ns->head->ns_id >= desc->nsids[n]: skip to desc->nsids[n+1]
This enables correct operation in the scenario described above. This also allows ANA log to contain nsids currently invisible to the host, i.e. inactive nsids.
Signed-off-by: Anton Eidelman anton@lightbitslabs.com Reviewed-by: James Smart james.smart@broadcom.com Reviewed-by: Hannes Reinecke hare@suse.com Reviewed-by: Christoph Hellwig hch@lst.de Signed-off-by: Sagi Grimberg sagi@grimberg.me Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/nvme/host/multipath.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c index 304aa8a65f2f8..f928bcfc57b5b 100644 --- a/drivers/nvme/host/multipath.c +++ b/drivers/nvme/host/multipath.c @@ -501,14 +501,16 @@ static int nvme_update_ana_state(struct nvme_ctrl *ctrl,
down_write(&ctrl->namespaces_rwsem); list_for_each_entry(ns, &ctrl->namespaces, list) { - if (ns->head->ns_id != le32_to_cpu(desc->nsids[n])) + unsigned nsid = le32_to_cpu(desc->nsids[n]); + + if (ns->head->ns_id < nsid) continue; - nvme_update_ns_ana_state(desc, ns); + if (ns->head->ns_id == nsid) + nvme_update_ns_ana_state(desc, ns); if (++n == nr_nsids) break; } up_write(&ctrl->namespaces_rwsem); - WARN_ON_ONCE(n < nr_nsids); return 0; }