From mboxrd@z Thu Jan 1 00:00:00 1970 From: sashal@kernel.org (Sasha Levin) Date: Wed, 5 Dec 2018 04:42:38 -0500 Subject: [PATCH AUTOSEL 4.14 60/69] nvme: flush namespace scanning work just before removing namespaces In-Reply-To: <20181205094247.6556-1-sashal@kernel.org> References: <20181205094247.6556-1-sashal@kernel.org> Message-ID: <20181205094247.6556-60-sashal@kernel.org> From: Sagi Grimberg [ 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 Signed-off-by: Sagi Grimberg Reviewed-by: Keith Busch Reviewed by: James Smart Tested-by: Ewan D. Milne Signed-off-by: Christoph Hellwig Signed-off-by: Sasha Levin --- 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); -- 2.17.1