[PATCH 1/4] nvme-pci: introduce RECONNECTING state to mark initializing procedure

From: Jianchao Wang
Date: Mon Jan 22 2018 - 09:02:45 EST


After Sagi's commit (nvme-rdma: fix concurrent reset and reconnect),
both nvme-fc/rdma have following pattern:
RESETTING - quiesce blk-mq queues, teardown and delete queues/
connections, clear out outstanding IO requests...
RECONNECTING - establish new queues/connections and some other
initializing things.
Introduce RECONNECTING to nvme-pci transport to do the same mark.
Then we get a coherent state definition among nvme pci/rdma/fc
transports.

Suggested-by: James Smart <james.smart@xxxxxxxxxxxx>
Reviewed-by: James Smart <james.smart@xxxxxxxxxxxx>
Signed-off-by: Jianchao Wang <jianchao.w.wang@xxxxxxxxxx>
---
drivers/nvme/host/core.c | 2 +-
drivers/nvme/host/pci.c | 19 +++++++++++++++++--
2 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 230cc09..23b3e53 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -242,7 +242,7 @@ bool nvme_change_ctrl_state(struct nvme_ctrl *ctrl,
switch (new_state) {
case NVME_CTRL_ADMIN_ONLY:
switch (old_state) {
- case NVME_CTRL_RESETTING:
+ case NVME_CTRL_RECONNECTING:
changed = true;
/* FALLTHRU */
default:
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 45f843d..05344be 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -1138,9 +1138,14 @@ 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)
+ /* If there is a reset/reinit ongoing, we shouldn't reset again. */
+ switch (dev->ctrl.state) {
+ case NVME_CTRL_RESETTING:
+ case NVME_CTRL_RECONNECTING:
return false;
+ default:
+ break;
+ }

/* We shouldn't reset unless the controller is on fatal error state
* _or_ if we lost the communication with it.
@@ -2304,6 +2309,16 @@ static void nvme_reset_work(struct work_struct *work)
if (dev->ctrl.ctrl_config & NVME_CC_ENABLE)
nvme_dev_disable(dev, false);

+ /*
+ * Introduce RECONNECTING state from nvme-fc/rdma transports to mark the
+ * initializing procedure here.
+ */
+ if (!nvme_change_ctrl_state(&dev->ctrl, NVME_CTRL_RECONNECTING)) {
+ dev_warn(dev->ctrl.device,
+ "failed to mark controller RECONNECTING\n");
+ goto out;
+ }
+
result = nvme_pci_enable(dev);
if (result)
goto out;
--
2.7.4