[PATCH v3 6/7] nvme-pci: trigger device coredump on command timeout

Akinobu Mita
2019-05-12T15:55:02Z

This enables the nvme driver to trigger a device coredump when command
timeout occurs, and it helps diagnose and debug issues.

This can be tested with fail_io_timeout fault injection.

# echo 1 > /sys/kernel/debug/fail_io_timeout/probability
# echo 1 > /sys/kernel/debug/fail_io_timeout/times
# echo 1 > /sys/block/nvme0n1/io-timeout-fail
# dd if=/dev/nvme0n1 of=/dev/null

Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Jens Axboe <axboe@fb.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Minwoo Im <minwoo.im.dev@gmail.com>
Cc: Kenneth Heitke <kenneth.heitke@intel.com>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
---
* v3
- Don't try to get telemetry log when admin queue is not available

drivers/nvme/host/pci.c | 39 +++++++++++++++++++++++----------------
1 file changed, 23 insertions(+), 16 deletions(-)

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 3eebb98..6522592 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -87,12 +87,12 @@ MODULE_PARM_DESC(poll_queues, "Number of queues to use for polled IO.");
struct nvme_dev;
struct nvme_queue;

-static void nvme_dev_disable(struct nvme_dev *dev, bool shutdown);
+static void nvme_dev_disable(struct nvme_dev *dev, bool shutdown, bool dump);
static bool __nvme_disable_io_queues(struct nvme_dev *dev, u8 opcode);

-static void __maybe_unused nvme_coredump_init(struct nvme_dev *dev);
-static void __maybe_unused nvme_coredump_logs(struct nvme_dev *dev);
-static void __maybe_unused nvme_coredump_complete(struct nvme_dev *dev);
+static void nvme_coredump_init(struct nvme_dev *dev);
+static void nvme_coredump_logs(struct nvme_dev *dev);
+static void nvme_coredump_complete(struct nvme_dev *dev);

/*
* Represents an NVM Express device. Each nvme_dev is a PCI function.
@@ -1280,7 +1280,7 @@ static enum blk_eh_timer_return nvme_timeout(struct request *req, bool reserved)
*/
if (nvme_should_reset(dev, csts)) {
nvme_warn_reset(dev, csts);
- nvme_dev_disable(dev, false);
+ nvme_dev_disable(dev, false, true);
nvme_reset_ctrl(&dev->ctrl);
return BLK_EH_DONE;
}
@@ -1309,7 +1309,7 @@ static enum blk_eh_timer_return nvme_timeout(struct request *req, bool reserved)
dev_warn_ratelimited(dev->ctrl.device,
"I/O %d QID %d timeout, disable controller\n",
req->tag, nvmeq->qid);
- nvme_dev_disable(dev, shutdown);
+ nvme_dev_disable(dev, shutdown, true);
nvme_req(req)->flags |= NVME_REQ_CANCELLED;
return BLK_EH_DONE;
default:
@@ -1325,7 +1325,7 @@ static enum blk_eh_timer_return nvme_timeout(struct request *req, bool reserved)
dev_warn(dev->ctrl.device,
"I/O %d QID %d timeout, reset controller\n",
req->tag, nvmeq->qid);
- nvme_dev_disable(dev, false);
+ nvme_dev_disable(dev, false, true);
nvme_reset_ctrl(&dev->ctrl);

nvme_req(req)->flags |= NVME_REQ_CANCELLED;
@@ -2382,7 +2382,7 @@ static void nvme_pci_disable(struct nvme_dev *dev)
}
}

-static void nvme_dev_disable(struct nvme_dev *dev, bool shutdown)
+static void nvme_dev_disable(struct nvme_dev *dev, bool shutdown, bool dump)
{
bool dead = true;
struct pci_dev *pdev = to_pci_dev(dev->dev);
@@ -2407,6 +2407,9 @@ static void nvme_dev_disable(struct nvme_dev *dev, bool shutdown)
nvme_wait_freeze_timeout(&dev->ctrl, NVME_IO_TIMEOUT);
}

+ if (dump)
+ nvme_coredump_init(dev);
+
nvme_stop_queues(&dev->ctrl);

if (!dead && dev->ctrl.queue_count > 0) {
@@ -2477,7 +2480,7 @@ static void nvme_remove_dead_ctrl(struct nvme_dev *dev, int status)
dev_warn(dev->ctrl.device, "Removing after probe failure status: %d\n", status);

nvme_get_ctrl(&dev->ctrl);
- nvme_dev_disable(dev, false);
+ nvme_dev_disable(dev, false, false);
nvme_kill_queues(&dev->ctrl);
if (!queue_work(nvme_wq, &dev->remove_work))
nvme_put_ctrl(&dev->ctrl);
@@ -2499,7 +2502,7 @@ static void nvme_reset_work(struct work_struct *work)
* moving on.
*/
if (dev->ctrl.ctrl_config & NVME_CC_ENABLE)
- nvme_dev_disable(dev, false);
+ nvme_dev_disable(dev, false, false);

mutex_lock(&dev->shutdown_lock);
result = nvme_pci_enable(dev);
@@ -2536,6 +2539,9 @@ static void nvme_reset_work(struct work_struct *work)
if (result)
goto out;

+ nvme_coredump_logs(dev);
+ nvme_coredump_complete(dev);
+
if (dev->ctrl.oacs & NVME_CTRL_OACS_SEC_SUPP) {
if (!dev->ctrl.opal_dev)
dev->ctrl.opal_dev =
@@ -2598,6 +2604,7 @@ static void nvme_reset_work(struct work_struct *work)
out_unlock:
mutex_unlock(&dev->shutdown_lock);
out:
+ nvme_coredump_complete(dev);
nvme_remove_dead_ctrl(dev, result);
}

@@ -2788,7 +2795,7 @@ static int nvme_probe(struct pci_dev *pdev, const struct pci_device_id *id)
static void nvme_reset_prepare(struct pci_dev *pdev)
{
struct nvme_dev *dev = pci_get_drvdata(pdev);
- nvme_dev_disable(dev, false);
+ nvme_dev_disable(dev, false, false);
}

static void nvme_reset_done(struct pci_dev *pdev)
@@ -2800,7 +2807,7 @@ static void nvme_reset_done(struct pci_dev *pdev)
static void nvme_shutdown(struct pci_dev *pdev)
{
struct nvme_dev *dev = pci_get_drvdata(pdev);
- nvme_dev_disable(dev, true);
+ nvme_dev_disable(dev, true, false);
}

/*
@@ -2817,14 +2824,14 @@ static void nvme_remove(struct pci_dev *pdev)

if (!pci_device_is_present(pdev)) {
nvme_change_ctrl_state(&dev->ctrl, NVME_CTRL_DEAD);
- nvme_dev_disable(dev, true);
+ nvme_dev_disable(dev, true, false);
nvme_dev_remove_admin(dev);
}

flush_work(&dev->ctrl.reset_work);
nvme_stop_ctrl(&dev->ctrl);
nvme_remove_namespaces(&dev->ctrl);
- nvme_dev_disable(dev, true);
+ nvme_dev_disable(dev, true, false);
nvme_release_cmb(dev);
nvme_free_host_mem(dev);
nvme_dev_remove_admin(dev);
@@ -2841,7 +2848,7 @@ static int nvme_suspend(struct device *dev)
struct pci_dev *pdev = to_pci_dev(dev);
struct nvme_dev *ndev = pci_get_drvdata(pdev);

- nvme_dev_disable(ndev, true);
+ nvme_dev_disable(ndev, true, false);
return 0;
}

@@ -3313,7 +3320,7 @@ static pci_ers_result_t nvme_error_detected(struct pci_dev *pdev,
case pci_channel_io_frozen:
dev_warn(dev->ctrl.device,
"frozen state error detected, reset controller\n");
- nvme_dev_disable(dev, false);
+ nvme_dev_disable(dev, false, false);
return PCI_ERS_RESULT_NEED_RESET;
case pci_channel_io_perm_failure:
dev_warn(dev->ctrl.device,
--
2.7.4