nvme-fc: retry initial controller connections 3 times

Currently, if a frame is lost of command fails as part of initial
association create for a new controller, the new controller connection
request will immediately fail.

Add in an immediate 3 retry loop before giving up.

Signed-off-by: James Smart <james.smart@broadcom.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
index 8182b19..be49d0f 100644 (file)
--- a/drivers/nvme/host/fc.c
+++ b/drivers/nvme/host/fc.c
@@ -2734,7 +2734,7 @@ nvme_fc_init_ctrl(struct device *dev, struct nvmf_ctrl_options *opts,
 {
        struct nvme_fc_ctrl *ctrl;
        unsigned long flags;
-       int ret, idx;
+       int ret, idx, retry;
 
        if (!(rport->remoteport.port_role &
            (FC_PORT_ROLE_NVME_DISCOVERY | FC_PORT_ROLE_NVME_TARGET))) {
@@ -2826,9 +2826,37 @@ nvme_fc_init_ctrl(struct device *dev, struct nvmf_ctrl_options *opts,
        list_add_tail(&ctrl->ctrl_list, &rport->ctrl_list);
        spin_unlock_irqrestore(&rport->lock, flags);
 
-       ret = nvme_fc_create_association(ctrl);
+       /*
+        * It's possible that transactions used to create the association
+        * may fail. Examples: CreateAssociation LS or CreateIOConnection
+        * LS gets dropped/corrupted/fails; or a frame gets dropped or a
+        * command times out for one of the actions to init the controller
+        * (Connect, Get/Set_Property, Set_Features, etc). Many of these
+        * transport errors (frame drop, LS failure) inherently must kill
+        * the association. The transport is coded so that any command used
+        * to create the association (prior to a LIVE state transition
+        * while NEW or RECONNECTING) will fail if it completes in error or
+        * times out.
+        *
+        * As such: as the connect request was mostly likely due to a
+        * udev event that discovered the remote port, meaning there is
+        * not an admin or script there to restart if the connect
+        * request fails, retry the initial connection creation up to
+        * three times before giving up and declaring failure.
+        */
+       for (retry = 0; retry < 3; retry++) {
+               ret = nvme_fc_create_association(ctrl);
+               if (!ret)
+                       break;
+       }
+
        if (ret) {
+               /* couldn't schedule retry - fail out */
+               dev_err(ctrl->ctrl.device,
+                       "NVME-FC{%d}: Connect retry failed\n", ctrl->cnum);
+
                ctrl->ctrl.opts = NULL;
+
                /* initiate nvme ctrl ref counting teardown */
                nvme_uninit_ctrl(&ctrl->ctrl);
                nvme_put_ctrl(&ctrl->ctrl);