From: Nigel Kirkland nigel.kirkland@broadcom.com
[ Upstream commit 97b2512ad000a409b4073dd1a71e4157d76675cb ]
Delayed keep alive work is queued on system workqueue and may be cancelled via nvme_stop_keep_alive from nvme_reset_wq, nvme_fc_wq or nvme_wq.
Check_flush_dependency detects mismatched attributes between the work-queue context used to cancel the keep alive work and system-wq. Specifically system-wq does not have the WQ_MEM_RECLAIM flag, whereas the contexts used to cancel keep alive work have WQ_MEM_RECLAIM flag.
Example warning:
workqueue: WQ_MEM_RECLAIM nvme-reset-wq:nvme_fc_reset_ctrl_work [nvme_fc] is flushing !WQ_MEM_RECLAIM events:nvme_keep_alive_work [nvme_core]
To avoid the flags mismatch, delayed keep alive work is queued on nvme_wq.
However this creates a secondary concern where work and a request to cancel that work may be in the same work queue - namely err_work in the rdma and tcp transports, which will want to flush/cancel the keep alive work which will now be on nvme_wq.
After reviewing the transports, it looks like err_work can be moved to nvme_reset_wq. In fact that aligns them better with transition into RESETTING and performing related reset work in nvme_reset_wq.
Change nvme-rdma and nvme-tcp to perform err_work in nvme_reset_wq.
Signed-off-by: Nigel Kirkland nigel.kirkland@broadcom.com Signed-off-by: James Smart jsmart2021@gmail.com Reviewed-by: Sagi Grimberg sagi@grimberg.me Reviewed-by: Christoph Hellwig hch@lst.de Signed-off-by: Keith Busch kbusch@kernel.org Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/nvme/host/core.c | 10 +++++----- drivers/nvme/host/rdma.c | 2 +- drivers/nvme/host/tcp.c | 2 +- 3 files changed, 7 insertions(+), 7 deletions(-)
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index e703827d27e9c..7dacfd102a992 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -66,8 +66,8 @@ MODULE_PARM_DESC(streams, "turn on support for Streams write directives"); * nvme_reset_wq - hosts nvme reset works * nvme_delete_wq - hosts nvme delete works * - * nvme_wq will host works such are scan, aen handling, fw activation, - * keep-alive error recovery, periodic reconnects etc. nvme_reset_wq + * nvme_wq will host works such as scan, aen handling, fw activation, + * keep-alive, periodic reconnects etc. nvme_reset_wq * runs reset works which also flush works hosted on nvme_wq for * serialization purposes. nvme_delete_wq host controller deletion * works which flush reset works for serialization. @@ -972,7 +972,7 @@ static void nvme_keep_alive_end_io(struct request *rq, blk_status_t status) startka = true; spin_unlock_irqrestore(&ctrl->lock, flags); if (startka) - schedule_delayed_work(&ctrl->ka_work, ctrl->kato * HZ); + queue_delayed_work(nvme_wq, &ctrl->ka_work, ctrl->kato * HZ); }
static int nvme_keep_alive(struct nvme_ctrl *ctrl) @@ -1002,7 +1002,7 @@ static void nvme_keep_alive_work(struct work_struct *work) dev_dbg(ctrl->device, "reschedule traffic based keep-alive timer\n"); ctrl->comp_seen = false; - schedule_delayed_work(&ctrl->ka_work, ctrl->kato * HZ); + queue_delayed_work(nvme_wq, &ctrl->ka_work, ctrl->kato * HZ); return; }
@@ -1019,7 +1019,7 @@ static void nvme_start_keep_alive(struct nvme_ctrl *ctrl) if (unlikely(ctrl->kato == 0)) return;
- schedule_delayed_work(&ctrl->ka_work, ctrl->kato * HZ); + queue_delayed_work(nvme_wq, &ctrl->ka_work, ctrl->kato * HZ); }
void nvme_stop_keep_alive(struct nvme_ctrl *ctrl) diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c index cb4c3000a57e8..4ff51da3b13fa 100644 --- a/drivers/nvme/host/rdma.c +++ b/drivers/nvme/host/rdma.c @@ -1088,7 +1088,7 @@ static void nvme_rdma_error_recovery(struct nvme_rdma_ctrl *ctrl) if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_RESETTING)) return;
- queue_work(nvme_wq, &ctrl->err_work); + queue_work(nvme_reset_wq, &ctrl->err_work); }
static void nvme_rdma_wr_error(struct ib_cq *cq, struct ib_wc *wc, diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c index a870144542159..244984420b41b 100644 --- a/drivers/nvme/host/tcp.c +++ b/drivers/nvme/host/tcp.c @@ -422,7 +422,7 @@ static void nvme_tcp_error_recovery(struct nvme_ctrl *ctrl) if (!nvme_change_ctrl_state(ctrl, NVME_CTRL_RESETTING)) return;
- queue_work(nvme_wq, &to_tcp_ctrl(ctrl)->err_work); + queue_work(nvme_reset_wq, &to_tcp_ctrl(ctrl)->err_work); }
static int nvme_tcp_process_nvme_cqe(struct nvme_tcp_queue *queue,