4.14-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 <[email protected]> Signed-off-by: Sagi Grimberg <[email protected]> Reviewed-by: Keith Busch <[email protected]> Reviewed by: James Smart <[email protected]> Tested-by: Ewan D. Milne <[email protected]> Signed-off-by: Christoph Hellwig <[email protected]> Signed-off-by: Sasha Levin <[email protected]> --- 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 3a63d58d2ca9..65f3f1a34b6b 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -2572,6 +2572,9 @@ void nvme_remove_namespaces(struct nvme_ctrl *ctrl) { struct nvme_ns *ns, *next; + /* 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 @@ -2743,7 +2746,6 @@ void nvme_stop_ctrl(struct nvme_ctrl *ctrl) { nvme_stop_keep_alive(ctrl); flush_work(&ctrl->async_event_work); - flush_work(&ctrl->scan_work); cancel_work_sync(&ctrl->fw_act_work); } EXPORT_SYMBOL_GPL(nvme_stop_ctrl); -- 2.19.1
