[PATCH V4 1/2] nvme: add NVME_CTRL_RESET_PREPARE state

Jianchao Wang jianchao.w.wang at oracle.com
Tue Jan 16 20:54:36 PST 2018


Currently, the ctrl->state will be changed to NVME_CTRL_RESETTING
before queue the reset work. This is not so strict. There could be
a big gap before the reset_work callback is invoked. In addition,
there is some disable work in the reset_work callback, strictly
speaking, not part of reset work, and could lead to some confusion.

In addition, after set state to RESETTING and disable procedure,
nvme-rdma/fc use NVME_CTRL_RECONNECTING to mark the setup and
reconnect procedure. The RESETTING state has been narrowed.

This patch add NVME_CTRL_RESET_PREPARE state to mark the reset_work
or error recovery work, scheduling gap and disable procedure.
After that,
 - For nvme-pci, nvmet-loop, set state to RESETTING, start
   initialization.
 - For nvme-rdma, nvme-fc, set state to RECONNECTING, start
   initialization or reconnect.

Suggested-by: Christoph Hellwig <hch at lst.de>
Signed-off-by: Jianchao Wang <jianchao.w.wang at oracle.com>
---
 drivers/nvme/host/core.c   | 18 +++++++++++++++---
 drivers/nvme/host/fc.c     |  4 ++--
 drivers/nvme/host/nvme.h   |  8 ++++++++
 drivers/nvme/host/pci.c    | 25 +++++++++++++++++++++----
 drivers/nvme/host/rdma.c   |  2 +-
 drivers/nvme/target/loop.c |  5 +++++
 6 files changed, 52 insertions(+), 10 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 230cc09..87d209f 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -87,7 +87,7 @@ static __le32 nvme_get_log_dw10(u8 lid, size_t size)
 
 int nvme_reset_ctrl(struct nvme_ctrl *ctrl)
 {
-	if (!nvme_change_ctrl_state(ctrl, NVME_CTRL_RESETTING))
+	if (!nvme_change_ctrl_state(ctrl, NVME_CTRL_RESET_PREPARE))
 		return -EBUSY;
 	if (!queue_work(nvme_wq, &ctrl->reset_work))
 		return -EBUSY;
@@ -260,7 +260,7 @@ bool nvme_change_ctrl_state(struct nvme_ctrl *ctrl,
 			break;
 		}
 		break;
-	case NVME_CTRL_RESETTING:
+	case NVME_CTRL_RESET_PREPARE:
 		switch (old_state) {
 		case NVME_CTRL_NEW:
 		case NVME_CTRL_LIVE:
@@ -271,10 +271,20 @@ bool nvme_change_ctrl_state(struct nvme_ctrl *ctrl,
 			break;
 		}
 		break;
+
+	case NVME_CTRL_RESETTING:
+		switch (old_state) {
+		case NVME_CTRL_RESET_PREPARE:
+			changed = true;
+			/* FALLTHRU */
+		default:
+			break;
+		}
+		break;
 	case NVME_CTRL_RECONNECTING:
 		switch (old_state) {
 		case NVME_CTRL_LIVE:
-		case NVME_CTRL_RESETTING:
+		case NVME_CTRL_RESET_PREPARE:
 			changed = true;
 			/* FALLTHRU */
 		default:
@@ -286,6 +296,7 @@ bool nvme_change_ctrl_state(struct nvme_ctrl *ctrl,
 		case NVME_CTRL_LIVE:
 		case NVME_CTRL_ADMIN_ONLY:
 		case NVME_CTRL_RESETTING:
+		case NVME_CTRL_RESET_PREPARE:
 		case NVME_CTRL_RECONNECTING:
 			changed = true;
 			/* FALLTHRU */
@@ -2660,6 +2671,7 @@ static ssize_t nvme_sysfs_show_state(struct device *dev,
 		[NVME_CTRL_LIVE]	= "live",
 		[NVME_CTRL_ADMIN_ONLY]	= "only-admin",
 		[NVME_CTRL_RESETTING]	= "resetting",
+		[NVME_CTRL_RESET_PREPARE]	= "reset-prepare",
 		[NVME_CTRL_RECONNECTING]= "reconnecting",
 		[NVME_CTRL_DELETING]	= "deleting",
 		[NVME_CTRL_DEAD]	= "dead",
diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
index 306aee4..1ba0669 100644
--- a/drivers/nvme/host/fc.c
+++ b/drivers/nvme/host/fc.c
@@ -546,7 +546,7 @@ nvme_fc_resume_controller(struct nvme_fc_ctrl *ctrl)
 		queue_delayed_work(nvme_wq, &ctrl->connect_work, 0);
 		break;
 
-	case NVME_CTRL_RESETTING:
+	case NVME_CTRL_RESET_PREPARE:
 		/*
 		 * Controller is already in the process of terminating the
 		 * association. No need to do anything further. The reconnect
@@ -789,7 +789,7 @@ nvme_fc_ctrl_connectivity_loss(struct nvme_fc_ctrl *ctrl)
 		 */
 		break;
 
-	case NVME_CTRL_RESETTING:
+	case NVME_CTRL_RESET_PREPARE:
 		/*
 		 * Controller is already in the process of terminating the
 		 * association.  No need to do anything further. The reconnect
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index a44eeca..e4cae21 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -116,10 +116,18 @@ static inline struct nvme_request *nvme_req(struct request *req)
  */
 #define NVME_QUIRK_DELAY_AMOUNT		2300
 
+/*
+ * RESET_PREPARE - mark the state of scheduling gap and disable procedure
+ * RESETTING     - nvme-pci, nvmet loop use it to mark the state of setup
+ *				   procedure
+ * RECONNECTING  - nvme-fc, nvme-rdma use it to mark the state of setup
+ *				   and reconnect procedure
+ */
 enum nvme_ctrl_state {
 	NVME_CTRL_NEW,
 	NVME_CTRL_LIVE,
 	NVME_CTRL_ADMIN_ONLY,    /* Only admin queue live */
+	NVME_CTRL_RESET_PREPARE,
 	NVME_CTRL_RESETTING,
 	NVME_CTRL_RECONNECTING,
 	NVME_CTRL_DELETING,
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 45f843d..f4b47b9 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -1139,8 +1139,13 @@ static bool nvme_should_reset(struct nvme_dev *dev, u32 csts)
 	bool nssro = dev->subsystem && (csts & NVME_CSTS_NSSRO);
 
 	/* If there is a reset ongoing, we shouldn't reset again. */
-	if (dev->ctrl.state == NVME_CTRL_RESETTING)
+	switch (dev->ctrl.state) {
+	case NVME_CTRL_RESETTING:
+	case NVME_CTRL_RESET_PREPARE:
 		return false;
+	default:
+		break;
+	}
 
 	/* We shouldn't reset unless the controller is on fatal error state
 	 * _or_ if we lost the communication with it.
@@ -2181,9 +2186,16 @@ static void nvme_dev_disable(struct nvme_dev *dev, bool shutdown)
 	if (pci_is_enabled(pdev)) {
 		u32 csts = readl(dev->bar + NVME_REG_CSTS);
 
-		if (dev->ctrl.state == NVME_CTRL_LIVE ||
-		    dev->ctrl.state == NVME_CTRL_RESETTING)
+		switch (dev->ctrl.state) {
+		case NVME_CTRL_LIVE:
+		case NVME_CTRL_RESETTING:
+		case NVME_CTRL_RESET_PREPARE:
 			nvme_start_freeze(&dev->ctrl);
+			break;
+		default:
+			break;
+		}
+
 		dead = !!((csts & NVME_CSTS_CFS) || !(csts & NVME_CSTS_RDY) ||
 			pdev->error_state  != pci_channel_io_normal);
 	}
@@ -2294,7 +2306,7 @@ static void nvme_reset_work(struct work_struct *work)
 	int result = -ENODEV;
 	enum nvme_ctrl_state new_state = NVME_CTRL_LIVE;
 
-	if (WARN_ON(dev->ctrl.state != NVME_CTRL_RESETTING))
+	if (WARN_ON(dev->ctrl.state != NVME_CTRL_RESET_PREPARE))
 		goto out;
 
 	/*
@@ -2304,6 +2316,11 @@ static void nvme_reset_work(struct work_struct *work)
 	if (dev->ctrl.ctrl_config & NVME_CC_ENABLE)
 		nvme_dev_disable(dev, false);
 
+	if (!nvme_change_ctrl_state(&dev->ctrl, NVME_CTRL_RESETTING)) {
+		WARN_ON_ONCE(dev->ctrl.state != NVME_CTRL_DELETING);
+		goto out;
+	}
+
 	result = nvme_pci_enable(dev);
 	if (result)
 		goto out;
diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c
index d49b1e7..6b5f2f4 100644
--- a/drivers/nvme/host/rdma.c
+++ b/drivers/nvme/host/rdma.c
@@ -985,7 +985,7 @@ static void nvme_rdma_error_recovery_work(struct work_struct *work)
 
 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_RESET_PREPARE))
 		return;
 
 	queue_work(nvme_wq, &ctrl->err_work);
diff --git a/drivers/nvme/target/loop.c b/drivers/nvme/target/loop.c
index fdfcc96..cbc9249 100644
--- a/drivers/nvme/target/loop.c
+++ b/drivers/nvme/target/loop.c
@@ -481,6 +481,11 @@ static void nvme_loop_reset_ctrl_work(struct work_struct *work)
 	nvme_stop_ctrl(&ctrl->ctrl);
 	nvme_loop_shutdown_ctrl(ctrl);
 
+	changed = nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_RESETTING);
+	if (!changed) {
+		WARN_ON_ONCE(ctrl->ctrl.state != NVME_CTRL_DELETING);
+		return;
+	}
 	ret = nvme_loop_configure_admin_queue(ctrl);
 	if (ret)
 		goto out_disable;
-- 
2.7.4




More information about the Linux-nvme mailing list