Commit 97b2512a authored by Nigel Kirkland's avatar Nigel Kirkland Committed by Jens Axboe

nvme: prevent warning triggered by nvme_stop_keep_alive

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: default avatarNigel Kirkland <nigel.kirkland@broadcom.com>
Signed-off-by: default avatarJames Smart <jsmart2021@gmail.com>
Reviewed-by: default avatarSagi Grimberg <sagi@grimberg.me>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarKeith Busch <kbusch@kernel.org>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 2d570a7c
...@@ -66,8 +66,8 @@ MODULE_PARM_DESC(streams, "turn on support for Streams write directives"); ...@@ -66,8 +66,8 @@ MODULE_PARM_DESC(streams, "turn on support for Streams write directives");
* nvme_reset_wq - hosts nvme reset works * nvme_reset_wq - hosts nvme reset works
* nvme_delete_wq - hosts nvme delete works * nvme_delete_wq - hosts nvme delete works
* *
* nvme_wq will host works such are scan, aen handling, fw activation, * nvme_wq will host works such as scan, aen handling, fw activation,
* keep-alive error recovery, periodic reconnects etc. nvme_reset_wq * keep-alive, periodic reconnects etc. nvme_reset_wq
* runs reset works which also flush works hosted on nvme_wq for * runs reset works which also flush works hosted on nvme_wq for
* serialization purposes. nvme_delete_wq host controller deletion * serialization purposes. nvme_delete_wq host controller deletion
* works which flush reset works for serialization. * works which flush reset works for serialization.
...@@ -976,7 +976,7 @@ static void nvme_keep_alive_end_io(struct request *rq, blk_status_t status) ...@@ -976,7 +976,7 @@ static void nvme_keep_alive_end_io(struct request *rq, blk_status_t status)
startka = true; startka = true;
spin_unlock_irqrestore(&ctrl->lock, flags); spin_unlock_irqrestore(&ctrl->lock, flags);
if (startka) 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) static int nvme_keep_alive(struct nvme_ctrl *ctrl)
...@@ -1006,7 +1006,7 @@ static void nvme_keep_alive_work(struct work_struct *work) ...@@ -1006,7 +1006,7 @@ static void nvme_keep_alive_work(struct work_struct *work)
dev_dbg(ctrl->device, dev_dbg(ctrl->device,
"reschedule traffic based keep-alive timer\n"); "reschedule traffic based keep-alive timer\n");
ctrl->comp_seen = false; 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; return;
} }
...@@ -1023,7 +1023,7 @@ static void nvme_start_keep_alive(struct nvme_ctrl *ctrl) ...@@ -1023,7 +1023,7 @@ static void nvme_start_keep_alive(struct nvme_ctrl *ctrl)
if (unlikely(ctrl->kato == 0)) if (unlikely(ctrl->kato == 0))
return; 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) void nvme_stop_keep_alive(struct nvme_ctrl *ctrl)
......
...@@ -1088,7 +1088,7 @@ static void nvme_rdma_error_recovery(struct nvme_rdma_ctrl *ctrl) ...@@ -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)) if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_RESETTING))
return; 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, static void nvme_rdma_wr_error(struct ib_cq *cq, struct ib_wc *wc,
......
...@@ -422,7 +422,7 @@ static void nvme_tcp_error_recovery(struct nvme_ctrl *ctrl) ...@@ -422,7 +422,7 @@ static void nvme_tcp_error_recovery(struct nvme_ctrl *ctrl)
if (!nvme_change_ctrl_state(ctrl, NVME_CTRL_RESETTING)) if (!nvme_change_ctrl_state(ctrl, NVME_CTRL_RESETTING))
return; 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, static int nvme_tcp_process_nvme_cqe(struct nvme_tcp_queue *queue,
......
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