4.19-stable review patch. If anyone has any objections, please let me know. ------------------ [ Upstream commit f6c8e432cb0479255322c5d0335b9f1699a0270c ] nvme_stop_ctrl can be called also for reset flow and there is no need to flush the scan_work as namespaces are not being removed. This can cause deadlock in rdma, fc and loop drivers since nvme_stop_ctrl barriers before controller teardown (and specifically I/O cancellation of the scan_work itself) takes place, but the scan_work will be blocked anyways so there is no need to flush it. Instead, move scan_work flush to nvme_remove_namespaces() where it really needs to flush. Reported-by: Ming Lei <ming.lei@xxxxxxxxxx> Signed-off-by: Sagi Grimberg <sagi@xxxxxxxxxxx> Reviewed-by: Keith Busch <keith.busch@xxxxxxxxx> Reviewed by: James Smart <jsmart2021@xxxxxxxxx> Tested-by: Ewan D. Milne <emilne@xxxxxxxxxx> Signed-off-by: Christoph Hellwig <hch@xxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/nvme/host/core.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index 0ba301f7e8b4..b7b2659e02fa 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -3308,6 +3308,9 @@ void nvme_remove_namespaces(struct nvme_ctrl *ctrl) struct nvme_ns *ns, *next; LIST_HEAD(ns_list); + /* prevent racing with ns scanning */ + flush_work(&ctrl->scan_work); + /* * The dead states indicates the controller was not gracefully * disconnected. In that case, we won't be able to flush any data while @@ -3463,7 +3466,6 @@ void nvme_stop_ctrl(struct nvme_ctrl *ctrl) nvme_mpath_stop(ctrl); nvme_stop_keep_alive(ctrl); flush_work(&ctrl->async_event_work); - flush_work(&ctrl->scan_work); cancel_work_sync(&ctrl->fw_act_work); if (ctrl->ops->stop_ctrl) ctrl->ops->stop_ctrl(ctrl); -- 2.19.1
