From: James Smart <jsmart2021@gmail.com>
Date: Wed, 13 Jun 2018 14:07:37 -0700
Subject: [PATCH] nvme-fc: change controllers first connect to use reconnect
path
References: bsc#1098706
Git-commit: 4c984154efa13175bbb1e2aeb1de9fb2960ca28c
Patch-mainline: v4.18-rc1
Current code follows the framework that has been in the transports
from the beginning where initial link-side controller connect occurs
as part of "creating the controller". Thus that first connect fully
talks to the controller and obtains values that can then be used in
for blk-mq setup, etc. It also means that everything about the
controller is fully know before the "create controller" call returns.
This has several weaknesses:
- The initial create_ctrl call made by the cli will block for a long
time as wire transactions are performed synchronously. This delay
becomes longer if errors occur or connectivity is lost and retries
need to be performed.
- Code wise, it means there is a separate connect path for initial
controller connect vs the (same) steps used in the reconnect path.
- And as there's separate paths, it means there's separate error
handling and retry logic. It also plays havoc with the NEW state
(should transition out of it after successful initial connect) vs
the RESETTING and CONNECTING (reconnect) states that want to be
transitioned to on error.
- As there's separate paths, to recover from errors and disruptions,
it requires separate recovery/retry paths as well and can severely
convolute the controller state.
This patch reworks the fc transport to use the same connect paths
for the initial connection as it uses for reconnect. This makes a
single path for error recovery and handling.
This patch:
- Removes the driving of the initial connect and replaces it with
a state transition to CONNECTING and initiating the reconnect
thread. A dummy state transition of RESETTING had to be traversed
as a direct transtion of NEW->CONNECTING is not allowed. Given
that the controller is "new", the RESETTING transition is a simple
no-op. Once in the reconnecting thread, the normal behaviors of
ctrl_loss_tmo (max_retries * connect_delay) and dev_loss_tmo will
apply before the controller is torn down.
- Only if the state transitions couldn't be traversed and the
reconnect thread not scheduled, will the controller be torn down
while in create_ctrl.
- The prior code used the controller state of NEW to indicate
whether request queues had been initialized or not. For the admin
queue, the request queue is always created, so there's no need to
check a state. For IO queues, change to tracking whether a successful
io request queue create has occurred (e.g. 1st successful connect).
- The initial controller id is initialized to the dynamic controller
id used in the initial connect message. It will be overwritten by
the real controller id once the controller is connected on the wire.
Signed-off-by: James Smart <james.smart@broadcom.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Hannes Reinecke <hare@suse.de>
---
drivers/nvme/host/fc.c | 104 ++++++++++++++++++++++---------------------------
1 file changed, 47 insertions(+), 57 deletions(-)
diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
index 46bf6b332167..0794f2707a9a 100644
--- a/drivers/nvme/host/fc.c
+++ b/drivers/nvme/host/fc.c
@@ -144,6 +144,7 @@ struct nvme_fc_ctrl {
struct nvme_fc_rport *rport;
u32 cnum;
+ bool ioq_live;
bool assoc_active;
u64 association_id;
@@ -2473,6 +2474,8 @@ nvme_fc_create_io_queues(struct nvme_fc_ctrl *ctrl)
if (ret)
goto out_delete_hw_queues;
+ ctrl->ioq_live = true;
+
return 0;
out_delete_hw_queues:
@@ -2625,8 +2628,7 @@ nvme_fc_create_association(struct nvme_fc_ctrl *ctrl)
if (ret)
goto out_delete_hw_queue;
- if (ctrl->ctrl.state != NVME_CTRL_NEW)
- blk_mq_unquiesce_queue(ctrl->ctrl.admin_q);
+ blk_mq_unquiesce_queue(ctrl->ctrl.admin_q);
ret = nvmf_connect_admin_queue(&ctrl->ctrl);
if (ret)
@@ -2699,7 +2701,7 @@ nvme_fc_create_association(struct nvme_fc_ctrl *ctrl)
*/
if (ctrl->ctrl.queue_count > 1) {
- if (ctrl->ctrl.state == NVME_CTRL_NEW)
+ if (!ctrl->ioq_live)
ret = nvme_fc_create_io_queues(ctrl);
else
ret = nvme_fc_reinit_io_queues(ctrl);
@@ -2786,8 +2788,7 @@ nvme_fc_delete_association(struct nvme_fc_ctrl *ctrl)
* use blk_mq_tagset_busy_itr() and the transport routine to
* terminate the exchanges.
*/
- if (ctrl->ctrl.state != NVME_CTRL_NEW)
- blk_mq_quiesce_queue(ctrl->ctrl.admin_q);
+ blk_mq_quiesce_queue(ctrl->ctrl.admin_q);
blk_mq_tagset_busy_iter(&ctrl->admin_tag_set,
nvme_fc_terminate_exchange, &ctrl->ctrl);
@@ -2945,7 +2946,7 @@ nvme_fc_connect_ctrl_work(struct work_struct *work)
nvme_fc_reconnect_or_delete(ctrl, ret);
else
dev_info(ctrl->ctrl.device,
- "NVME-FC{%d}: controller reconnect complete\n",
+ "NVME-FC{%d}: controller connect complete\n",
ctrl->cnum);
}
@@ -2993,7 +2994,7 @@ nvme_fc_init_ctrl(struct device *dev, struct nvmf_ctrl_options *opts,
{
struct nvme_fc_ctrl *ctrl;
unsigned long flags;
- int ret, idx, retry;
+ int ret, idx;
if (!(rport->remoteport.port_role &
(FC_PORT_ROLE_NVME_DISCOVERY | FC_PORT_ROLE_NVME_TARGET))) {
@@ -3020,11 +3021,13 @@ nvme_fc_init_ctrl(struct device *dev, struct nvmf_ctrl_options *opts,
}
ctrl->ctrl.opts = opts;
+ ctrl->ctrl.nr_reconnects = 0;
INIT_LIST_HEAD(&ctrl->ctrl_list);
ctrl->lport = lport;
ctrl->rport = rport;
ctrl->dev = lport->dev;
ctrl->cnum = idx;
+ ctrl->ioq_live = false;
ctrl->assoc_active = false;
init_waitqueue_head(&ctrl->ioabort_wait);
@@ -3043,6 +3046,7 @@ nvme_fc_init_ctrl(struct device *dev, struct nvmf_ctrl_options *opts,
ctrl->ctrl.sqsize = opts->queue_size - 1;
ctrl->ctrl.kato = opts->kato;
+ ctrl->ctrl.cntlid = 0xffff;
ret = -ENOMEM;
ctrl->queues = kcalloc(ctrl->ctrl.queue_count,
@@ -3092,62 +3096,24 @@ 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);
- /*
- * 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 CONNECTING) 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) {
- nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_DELETING);
- cancel_work_sync(&ctrl->ctrl.reset_work);
- cancel_delayed_work_sync(&ctrl->connect_work);
-
- /* couldn't schedule retry - fail out */
+ if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_RESETTING) ||
+ !nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_CONNECTING)) {
dev_err(ctrl->ctrl.device,
- "NVME-FC{%d}: Connect retry failed\n", ctrl->cnum);
-
- ctrl->ctrl.opts = NULL;
+ "NVME-FC{%d}: failed to init ctrl state\n", ctrl->cnum);
+ goto fail_ctrl;
+ }
- /* initiate nvme ctrl ref counting teardown */
- nvme_uninit_ctrl(&ctrl->ctrl);
+ nvme_get_ctrl(&ctrl->ctrl);
- /* Remove core ctrl ref. */
+ if (!queue_delayed_work(nvme_wq, &ctrl->connect_work, 0)) {
nvme_put_ctrl(&ctrl->ctrl);
-
- /* as we're past the point where we transition to the ref
- * counting teardown path, if we return a bad pointer here,
- * the calling routine, thinking it's prior to the
- * transition, will do an rport put. Since the teardown
- * path also does a rport put, we do an extra get here to
- * so proper order/teardown happens.
- */
- nvme_fc_rport_get(rport);
-
- if (ret > 0)
- ret = -EIO;
- return ERR_PTR(ret);
+ dev_err(ctrl->ctrl.device,
+ "NVME-FC{%d}: failed to schedule initial connect\n",
+ ctrl->cnum);
+ goto fail_ctrl;
}
- nvme_get_ctrl(&ctrl->ctrl);
+ flush_delayed_work(&ctrl->connect_work);
dev_info(ctrl->ctrl.device,
"NVME-FC{%d}: new ctrl: NQN \"%s\"\n",
@@ -3155,6 +3121,30 @@ nvme_fc_init_ctrl(struct device *dev, struct nvmf_ctrl_options *opts,
return &ctrl->ctrl;
+fail_ctrl:
+ nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_DELETING);
+ cancel_work_sync(&ctrl->ctrl.reset_work);
+ cancel_delayed_work_sync(&ctrl->connect_work);
+
+ ctrl->ctrl.opts = NULL;
+
+ /* initiate nvme ctrl ref counting teardown */
+ nvme_uninit_ctrl(&ctrl->ctrl);
+
+ /* Remove core ctrl ref. */
+ nvme_put_ctrl(&ctrl->ctrl);
+
+ /* as we're past the point where we transition to the ref
+ * counting teardown path, if we return a bad pointer here,
+ * the calling routine, thinking it's prior to the
+ * transition, will do an rport put. Since the teardown
+ * path also does a rport put, we do an extra get here to
+ * so proper order/teardown happens.
+ */
+ nvme_fc_rport_get(rport);
+
+ return ERR_PTR(-EIO);
+
out_cleanup_admin_q:
blk_cleanup_queue(ctrl->ctrl.admin_q);
out_free_admin_tag_set:
--
2.12.3