nvme-pci: introduce RECONNECTING state to mark initializing procedure

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@broadcom.com>
Reviewed-by: James Smart <james.smart@broadcom.com>
Reviewed-by: Reviewed-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jianchao Wang <jianchao.w.wang@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

2 files changed, 18 insertions, 3 deletions

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index fde6fd2e7eef..63c2c469112d 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -260,7 +260,7 @@ 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 e2342d365d3c..0bc6a9e48c8e 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -1140,9 +1140,14 @@ 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.
@@ -2284,6 +2289,16 @@ 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;