From: Sagi Grimberg sagi@grimberg.me
commit 72e3b8883a36e80ebfa41015c7b6926ce31ace05 upstream.
When we revalidate paths as part of ns size change (as of commit e7d65803e2bb), it is possible that during the path revalidation, the only paths that is IO capable (i.e. optimized/non-optimized) are the ones that ns resize was not yet informed to the host, which will cause inflight requests to be requeued (as we have available paths but none are IO capable). These requests on the requeue list are waiting for someone to resubmit them at some point.
The IO capable paths will eventually notify the ns resize change to the host, but there is nothing that will kick the requeue list to resubmit the queued requests.
Fix this by always kicking the requeue list, and if no IO capable path exists, these requests will be queued again.
A typical log that indicates that IOs are requeued: -- nvme nvme1: creating 4 I/O queues. nvme nvme1: new ctrl: "testnqn1" nvme nvme2: creating 4 I/O queues. nvme nvme2: mapped 4/0/0 default/read/poll queues. nvme nvme2: new ctrl: NQN "testnqn1", addr 127.0.0.1:8009 nvme nvme1: rescanning namespaces. nvme1n1: detected capacity change from 2097152 to 4194304 block nvme1n1: no usable path - requeuing I/O block nvme1n1: no usable path - requeuing I/O block nvme1n1: no usable path - requeuing I/O block nvme1n1: no usable path - requeuing I/O block nvme1n1: no usable path - requeuing I/O block nvme1n1: no usable path - requeuing I/O block nvme1n1: no usable path - requeuing I/O block nvme1n1: no usable path - requeuing I/O block nvme1n1: no usable path - requeuing I/O block nvme1n1: no usable path - requeuing I/O nvme nvme2: rescanning namespaces. --
Reported-by: Yogev Cohen yogev@lightbitslabs.com Fixes: e7d65803e2bb ("nvme-multipath: revalidate paths during rescan") Signed-off-by: Sagi Grimberg sagi@grimberg.me Cc: stable@vger.kernel.org # v5.15+ Signed-off-by: Christoph Hellwig hch@lst.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/nvme/host/multipath.c | 1 + 1 file changed, 1 insertion(+)
--- a/drivers/nvme/host/multipath.c +++ b/drivers/nvme/host/multipath.c @@ -182,6 +182,7 @@ void nvme_mpath_revalidate_paths(struct
for_each_node(node) rcu_assign_pointer(head->current_path[node], NULL); + kblockd_schedule_work(&head->requeue_work); }
static bool nvme_path_is_disabled(struct nvme_ns *ns)